text:
Engineering Acoustics/Moving Coil Loudspeaker

=Moving Coil Transducer= The purpose of the acoustic transducer is to convert electrical energy into acoustic energy. Many variations of acoustic transducers exist, although the most common is the moving coil-permanent magnet transducer. The classic loudspeaker is of the moving coil-permanent magnet type.

The classic electrodynamic loudspeaker driver can be divided into three key components:

1) The Magnet Motor Drive System

2) The Loudspeaker Cone System

3) The Loudspeaker Suspension

Figure 1 Cut-away of a moving coil-permanent magnet loudspeaker

The Magnet Motor Drive System
The main purpose of the Magnet Motor Drive System is to establish a symmetrical magnetic field in which the voice coil will operate. The Magnet Motor Drive System is comprised of a front focusing plate, permanent magnet, back plate, and a pole piece. In figure 2, the assembled drive system is illustrated. In most cases, the back plate and the pole piece are built into one piece called the yoke. The yoke and the front focusing plate are normally made of a very soft cast iron. Iron is a material that is used in conjunction with magnetic structures because the iron is easily saturated when exposed to a magnetic field. Notice in figure 2, that an air gap was intentionally left between the front focusing plate and the yoke. The magnetic field is coupled through the air gap. The magnetic field strength (B) of the air gap is typically optimized for uniformity across the gap. [1]

Figure 2 Permanent Magnet Structure

When a coil of wire with a current flowing is place inside the permanent magnetic field, a force is produced. B is the magnetic field strength, l is the length of the coil, and I is the current flowing through the coil.

$$F = Bli$$

Figure 3 Voice Coil Mounted in Permanent Magnetic Structure

The coil is excited with the AC signal that is intended for sound reproduction, when the changing magnetic field of the coil interacts with the permanent magnetic field then the coil moves back and forth in order to reproduce the input signal. The coil of a loudspeaker is known as the voice coil.

Figure 4 Photograph - Voice Coil

The Loudspeaker Cone System
On a typical loudspeaker, the cone serves the purpose of creating a larger radiating area allowing more air to be moved when excited by the voice coil. The cone serves a piston that is excited by the voice coil. The cone then displaces air creating a sound wave. In an ideal environment, the cone should be infinitely rigid and have zero mass, but in reality neither is true. Cone materials vary from carbon fiber, paper, bamboo, and just about any other material that can be shaped into a stiff conical shape. The loudspeaker cone is a very critical part of the loudspeaker. Since the cone is not infinitely rigid, it tends to have different types of resonance modes form at different frequencies, which in turn alters and colors the reproduction of the sound waves. The shape of the cone directly influences the directivity and frequency response of the loudspeaker. When the cone is attached to the voice coil, a large gap above the voice coil is left exposed. This could be a problem if foreign particles make their way into the air gap of the voice coil and the permanent magnet structure. The solution to this problem is to place what is known as a dust cap on the cone to cover the air gap. Below a figure of the cone and dust cap are shown.

Figure 6 Cone and Dust Cap attached to Voice Coil

The Loudspeaker Suspension
Most moving coil loudspeakers have a two piece suspension system, also known as a flexure system. The combination of the two flexures allows the voice coil to maintain linear travel as the voice coil is energized and provide a restoring force for the voice coil system. The two piece system consists of large flexible membrane surrounding the outside edge of the cone, called the surround, and an additional flexure connected directly to the voice coil, called the spider. The surround has another purpose and that is to seal the loudspeaker when mounted in an enclosure. Commonly, the surround is made of a variety of different materials, such as, folded paper, cloth, rubber, and foam. Construction of the spider consists of different woven cloth or synthetic materials that are compressed to form a flexible membrane. The following two figures illustrate where the suspension components are physically at on the loudspeaker and how they function as the loudspeaker operates.

Figure 7 Loudspeaker Suspension System

Figure 8 Moving Loudspeaker

Modeling the Loudspeaker as a Lumped System
Before implementing a loudspeaker into a specific application, a series of parameters characterizing the loudspeaker must be extracted. The equivalent circuit of the loudspeaker is key when developing enclosures. The circuit models all aspects of the loudspeaker through an equivalent electrical, mechanical, and acoustical circuit. Figure 9 shows how the three equivalent circuits are connected. The electrical circuit is comprised of the DC resistance of the voice coil, Re, the imaginary part of the voice coil inductance, Le, and the real part of the voice coil inductance, Revc. The mechanical system has electrical components that model different physical parameters of the loudspeaker. In the mechanical circuit, Mm, is the electrical capacitance due to the moving mass, Cm, is the electrical inductance due to the compliance of the moving mass, and Rm, is the electrical resistance due to the suspension system. In the acoustical equivalent circuit, Ma models the air mass and Ra models the radiation impedance[2]. This equivalent circuit allows insight into what parameters change the characteristics of the loudspeaker. Figure 10 shows the electrical input impedance as a function of frequency developed using the equivalent circuit of the loudspeaker. Figure 9 Loudspeaker Analogous Circuit

Figure 10 Electrical Input Impedance


text:
Engineering Acoustics/Noise in Hydraulic Systems

Noise in Hydraulic Systems
Hydraulic systems are the most preferred source of power transmission in most of the industrial and mobile equipments due to their advantages in power density, compactness, flexibility, fast response and efficiency. The field hydraulics and pneumatics is also known as 'Fluid Power Technology'. Fluid power systems have a wide range of applications which include industrial, off-road vehicles, automotive system and aircrafts. In spite of these advantages, there are also some disadvantages. One of the main drawbacks with the hydraulic fluid power systems is the vibration and noise generated by them. The health and safety issues relating to noise, vibration and harshness (NVH) have been recognized for many years and legislation is now placing clear demands on manufacturers to reduce noise levels [1]. Hence, a lot of attention has been paid on reducing the noise of hydraulic fluid power systems both from the industrial and academic researchers. A good understanding of the noise generation, transmission and propagation is very important in order to improve the NVH performance of hydraulic fluid power systems.

Sound in fluids
The speed of sound in fluids can be determined using the following relation.

$$c = \sqrt {\frac{K}{\rho}} $$ where K - fluid bulk modulus, $$\rho $$- fluid density, c - velocity of sound

Typical value of bulk modulus range from 2e9 to 2.5e9 N/m2. For a particular oil, with a density of 889 kg/m3, speed of sound $$ c = \sqrt {\frac{2e9}{889}}= 1499.9 m/s $$

Source of Noise
The main source of noise in hydraulic systems is the pump which supplies the flow. Most of the pumps used are positive displacement pumps. Of the positive displacement pumps, axial piston swash plate type is mostly preferred due to their controllability and efficiency.

The noise generation in an axial piston pump can be classified under two categories: (i) fluidborne noise and

(ii) Structureborne noise

Fluidborne Noise (FBN)
Among the positive displacement pumps, highest levels of FBN are generated by axial piston pumps and lowest levels by screw pumps and in between these lie the external gear pump and vane pump [1]. The discussion in this page is mainly focused on axial piston swash plate type pumps. An axial piston pump has a fixed number of displacement chambers arranged in a circular pattern separated from each other by an angular pitch equal to $$ \phi = \frac {360}{n} $$ where n is the number of displacement chambers. As each chamber discharges a specific volume of fluid, the discharge at the pump outlet is sum of all the discharge from the individual chambers. The discontinuity in flow between adjacent chambers results in a kinematic flow ripple. The amplitude of the kinematic ripple can be theoretically determined given the size of the pump and the number of displament chambers. The kinematic ripple is the main cause of the fluidborne noise. The kinematic ripples is a theoretical value. The actual flow ripple at the pump outlet is much larger than the theoretical value because the kinematic ripple is combined with a compressibility component which is due to the fluid compressibility. These ripples (also referred as flow pulsations) generated at the pump are transmitted through the pipe or flexible hose connected to the pump and travel to all parts of the hydraulic circuit.

The pump is considered an ideal flow source. The pressure in the system will be decided by resistance to the flow or otherwise known as system load. The flow pulsations result in pressure pulsations. The pressure pulsations are superimposed on the mean system pressure. Both the flow and pressure pulsations easily travel to all part of the circuit and affect the performance of the components like control valve and actuators in the system and make the component vibrate, sometimes even resonate. This vibration of system components adds to the noise generated by the flow pulsations. The transmission of FBN in the circuit is discussed under transmission below.

A typical axial piston pump with 9 pistons running at 1000 rpm can produce a sound pressure level of more than 70 dBs.

Structureborne Noise (SBN)
In swash plate type pumps, the main sources of the structureborne noise are the fluctuating forces and moments of the swas plate. These fluctuating forces arise as a result of the varying pressure inside the displacement chamber. As the displacing elements move from suction stroke to discharge stroke, the pressure varies accordingly from few bars to few hundred bars. This pressure changes are reflected on the displacement elements (in this case, pistons) as forces and these force are exerted on the swash plate causing the swash plate to vibrate. This vibration of the swash plate is the main cause of structureborne noise. There are other components in the system which also vibrate and lead to structureborne noise, but the swash is the major contributor.

''' Fig. 1 shows an exploded view of axial piston pump. Also the flow pulsations and the oscillating forces on the swash plate, which cause FBN and SBN respectively are shown for one revolution of the pump. '''

FBN
The transmission of FBN is a complex phenomenon. Over the past few decades, considerable amount of research had gone into mathematical modeling of pressure and flow transient in the circuit. This involves the solution of wave equations, with piping treated as a distributed parameter system known as a transmission line [1] & [3].

Lets consider a simple pump-pipe-loading valve circuit as shown in Fig. 2. The pressure and flow ripple at ay location in the pipe can be described by the relations:

$$ \frac {}{} P = Ae^{-k x} + Be^{-k x}$$ .........(1)

$$ Q = \frac {1}{Z_{0}}(Ae^{-k x} - Be^{-k x})$$.....(2) where $$\frac {}{} A $$ and $$\frac {}{} B $$ are frequency dependent complex coefficients which are directly proportional to pump (source) flow ripple, but also functions of the source impedance $$\frac {}{} Z_{s}$$, characteristic impedance of the pipe $$\frac {}{} Z_{0}$$ and the termination impedance $$\frac {}{} Z_{t}$$. These impedances ,usually vary as the system operating pressure and flow rate changes, can be determined experimentally.

Fig.2 Schematic of a pump connected to a hydraulic line

For complex systems with several system components, the pressure and flow ripples are estimated using the transformation matrix approach. For this, the system components can be treated as lumped impedances (a throttle valve or accumulator), or distributed impedances (flexible hose or silencer). Various software packages are available today to predict the pressure pulsations.

SBN
The transmission of SBN follows the classic source-path-noise model. The vibrations of the swash plate, the main cause of SBN, is transferred to the pump casing which encloses all the rotating group in the pump including displacement chambers (also known as cylinder block), pistons and the swash plate. The pump case, apart from vibrating itself, transfers the vibration down to the mount on which the pump is mounted. The mount then passes the vibrations down to the main mounted structure or the vehicle. Thus the SBN is transferred from the swash plate to the main strucuture or vehicle via pumpcasing and mount.

Some of the machine structures, along the path of transmission, are good at transmitting this vribational energy and they even resonate and reinforce it. By converting only a fraction of 1% of the pump structureborne noise into sound, a member in the transmission path could radiate more ABN than the pump itself [4].

Airborne noise (ABN)
Both FBN and SBN, impart high fatigue loads on the system components and make them vibrate. All of these vibrations are radiated as airborne noise and can be heard by a human operator. Also, the flow and pressure pulsations make the system components such as a control valve to resonate. This vibration of the particular component again radiates airborne noise.

Noise reduction
The reduction of the noise radiated from the hydraulic system can be approached in two ways.

(i) Reduction at Source - which is the reduction of noise at the pump. A large amount of open literature are availabale on the reduction techniques with some techniques focusing on reducing FBN at source and others focusing on SBN. Reduction in FBN and SBN at the source has a large influence on the ABN that is radiated. Even though, a lot of progress had been made in reducing the FBN and SBN separately, the problem of noise in hydraulic systems is not fully solved and lot need to be done. The reason is that the FBN and SBN are interlated, in a sense that, if one tried to reduce the FBN at the pump, it tends to affect the SBN characteristics. Currently, one of the main researches in noise reduction in pumps, is a systematic approach in understanding the coupling between FBN and SBN and targeting them simultaneously instead of treating them as two separte sources. Such an unified approach, demands not only well trained researchers but also sophisticated computer based mathematical model of the pump which can accurately output the necessary results for optimization of pump design. The amplitude of fluid pulsations can be reduced, at the source, with the use of an hydraulic attenuator(5).

(ii) Reduction at Component level - which focuses on the reduction of noise from individual component like hose, control valve, pump mounts and fixtures. This can be accomplished by a suitable design modification of the component so that it radiates least amount of noise. Optimization using computer based models can be one of the ways.

Hydraulic System noise
Fig.3 Domain of hydraulic system noise generation and transmission (Figure recreated from [1])

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
Engineering Acoustics/Basic Acoustics of the Marimba

Introduction

Like a xylophone, a marimba has octaves of wooden bars that are struck with mallets to produce tones. Unlike the harsh sound of a xylophone, a marimba produces a deep, rich tone. Marimbas are not uncommon and are played in most high school bands.

Now, while all the trumpet and flute and clarinet players are busy tuning up their instruments, the marimba player is back in the percussion section with her feet up just relaxing. This is a bit surprising, however, since the marimba is a melodic instrument that needs to be in tune to sound good. So what gives? Why is the marimba never tuned? How would you even go about tuning a marimba? To answer these questions, the acoustics behind (or within) a marimba must be understood.

Components of Sound
What gives the marimba its unique sound? It can be boiled down to two components: the bars and the resonators. Typically, the bars are made of rosewood (or some synthetic version of wood). They are cut to size depending on what note is desired, then the tuning is refined by shaving wood from the underside of the bar.

Example: Rosewood bar, middle C, 1 cm thick
The resonators are made from metal (usually aluminum) and their lengths also differ depending on the desired note. It is important to know that each resonator is open at the top but closed by a stopper at the bottom end.

Resonator Shape
The shape of the resonator is an important factor in determining the quality of sound that can be produced. The ideal shape is a sphere. This is modeled by the Helmholtz resonator. (For more see Helmholtz Resonator page) However, mounting big, round, beach ball-like resonators under the keys is typically impractical. The worst choices for resonators are square or oval tubes. These shapes amplify the non-harmonic pitches sometimes referred to as “junk pitches”. The round tube is typically chosen because it does the best job (aside from the sphere) at amplifying the desired harmonic and not much else.

As mentioned in the second example above, the resonator on a marimba can be modeled by a closed pipe. This model can be used to predict what type of sound (full and rich vs dull) the marimba will produce. Each pipe is a "quarter wave resonator" that amplifies the sound waves produced by of the bar. This means that in order to produce a full, rich sound, the length of the resonator must exactly match one-quarter of the wavelength. If the length is off, the marimba will produce a dull or off-key sound for that note.

Why would the marimba need tuning?
In the theoretical world where it is always 72 degrees with low humidity, a marimba would not need tuning. But, since weather can be a factor (especially for the marching band) marimbas do not always perform the same way. Hot and cold weather can wreak havoc on all kinds of percussion instruments, and the marimba is no exception. On hot days, the marimba tends to be sharp and for cold days it tends to be flat. This is the exact opposite of what happens to string instruments. Why? The tone of a string instrument depends mainly on the tension in the string, which decreases as the string expands with heat. The decrease in tension leads to a flat note. Marimbas on the other hand produce sound by moving air through the resonators. The speed at which this air is moved is the speed of sound, which varies proportionately with temperature! So, as the temperature increases, so does the speed of sound. From the equation given in example 2 from above, you can see that an increase in the speed of sound (c) means a longer pipe is needed to resonate the same note. If the length of the resonator is not increased, the note will sound sharp. Now, the heat can also cause the wooden bars to expand, but the effect of this expansion is insignificant compared to the effect of the change in the speed of sound.

Tuning Myths
It is a common myth among percussionists that the marimba can be tuned by simply moving the resonators up or down (while the bars remain in the same position.) The thought behind this is that by moving the resonators down, for example, you are in effect lengthening them. While this may sound like sound reasoning, it actually does not hold true in practice. Judging by how the marimba is constructed (cutting bars and resonators to specific lengths), it seems that there are really two options to consider when looking to tune a marimba: shave some wood off the underside of the bars, or change the length of the resonator. For obvious reasons, shaving wood off the keys every time the weather changes is not a practical solution. Therefore, the only option left is to change the length of the resonator. As mentioned above, each resonator is plugged by a stopper at the bottom end. So, by simply shoving the stopper farther up the pipe, you can shorten the resonator and sharpen the note. Conversely, pushing the stopper down the pipe can flatten the note. Most marimbas do not come with tunable resonators, so this process can be a little challenging. (Broomsticks and hammers are common tools of the trade.)

Example: Middle C Resonator lengthened by 1 cm
The acoustics behind the tuning a marimba go back to the design that each resonator is to be ¼ of the total wavelength of the desired note. When marimbas get out of tune, this length is no longer exactly equal to ¼ the wavelength due to the lengthening or shortening of the resonator as described above. Because the length has changed, resonance is no longer achieved, and the tone can become muffled or off-key.

Conclusions
Some marimba builders are now changing their designs to include tunable resonators. There are in fact several marimba companies that have had tunable resonators for decades. However, only a few offer full range tuning. Since any leak in the end-seal will cause major loss of volume and richness of the tone, this is proving to be a very difficult task. At least now, though, armed with the acoustic background of their instruments, percussionists everywhere will now have something to do when the conductor says, “tune up!”

Links and References

 * 1)  http://www.gppercussion.com/html/resonators.html
 * 2)  http://www.mostlymarimba.com/
 * 3)  http://www.craftymusicteachers.com/bassmarimba/

Back to main page


text:
Georgia Water/External Links

 * Rivers, Lakes, Aquifers
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 * Major Water Projects
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title: Georgia Water/External Links


text:
Bartending/Contributors

The following have contributed to creating the Bartending Wikibook. This list includes those who contributed text under licences compatible with the GNU Free Documentation Licence, but not to Wikibooks itself. In particular it includes those who contributed to our sister project, Wikipedia.

 * 4.46.52.220
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 * AbsoluteArchitype
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External references
Cunningham, Stephen Kittredge, The Bartender's Black Book, 7th Edition. The Bartender's Black Book, Inc. (Brockton, MA), 2005, ISBN 0-9657746-4-3 Chambord, La Vie de Chambord Liqueur Dias-Blue, Anthony

Edwards, Griffith, M.D., Alcohol. St. Martin's Press, N.Y., 2002. Jose Cuervo (copyright) Drink Recipes, distillers recipe booklet terroir-france.com The German Wine Society Online Wineguide.com

title: Bartending/Contributors


text: User talk:68.41.254.251

title: User talk:68.41.254.251


text:
Talk:Saxophone/The Saxophone Family

If this is intended to be an introductory book for people learning to play the saxophone, I'm not sure what value there is in telling them about saxello's and tubaxes and the L.A. sax company and Jay C. Easton's homepage and such oddities. Wouldn't it be better to, say, touch on the main types, what key they're in, point out that the fingering is similar/the same for the whole lot of them, and then redirect them to Wikipedia for such minutiae as "L.A. Sax makes a straight alto" and "there are some sopranos that are curved"? Also there are a few statements in the current version ("Altos are not that difficult to play" and "Alto players will usually find it easy to play the baritone") which are subjective at best.

70.226.157.248 21:21, 21 March 2006 (UTC) JoAnne

title: Talk:Saxophone/The Saxophone Family


text:
Georgia Water/External Links/Library

General Library Information

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Documents listed by author
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See list of publications on each organization's webpage.

title: Georgia Water/External Links/Library


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text:
XML - Managing Data Exchange/Web Services/Exercises

Exercises
 1.Use the following WSDL file to create a SOAP request and response for getting the exchange rate between two countries.

<?xml version="1.0"?> <definitions name="CurrencyExchangeService" targetNamespace="http://www.xmethods.net/sd/CurrencyExchangeService.wsdl" xmlns:tns="http://www.xmethods.net/sd/CurrencyExchangeService.wsdl" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns="http://schemas.xmlsoap.org/wsdl/"> <message name="getRateRequest"> <part name="country1" type="xsd:string"/> <part name="country2" type="xsd:string"/> </message> <message name="getRateResponse"> <part name="Result" type="xsd:float"/> </message> <portType name="CurrencyExchangePortType"> <operation name="getRate"> <input message="tns:getRateRequest"/> <output message="tns:getRateResponse"/> </operation> </portType> <binding name="CurrencyExchangeBinding" type="tns:CurrencyExchangePortType"> <soap:binding style="rpc" transport="http://schemas.xmlsoap.org/soap/http"/> <operation name="getRate"> <soap:operation soapAction=""/> <input> <soap:body use="encoded" namespace="urn:xmethods-CurrencyExchang" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/> </input> <output> <soap:body use="encoded" namespace="urn:xmethods-CurrencyExchange" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/> </output> </operation> </binding>

<service name="CurrencyExchangeService"> <documentation>Returns the exchange rate between the two currencies</documentation> <port name="CurrencyExchangePort" binding="tns:CurrencyExchangeBinding"> <soap:address location="http://services.xmethods.net:80/soap"/> </port> </service>

</definitions>

2. Use the following SOAP request and response documents to create a WSDL file with the input being a city, and the output being population of that city.

Request

 <?xml version="1.0" encoding="UTF-8" standalone="no"?/> <SOAP-ENV:Envelope SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"> <SOAP-ENV:Body> <m:getPopulation xmlns:m="urn:xmethods-Population"> <city xsi:type="xsd:string">Athens </city> </m:getPopulation> </SOAP-ENV:Body> </SOAP-ENV:Envelope>

 Response

<?xml version="1.0" encoding="UTF-8" standalone="no"?/> <SOAP-ENV:Envelope SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"> <SOAP-ENV:Body> <SOAPSDK1:getPopulationResponse xmlns:SOAPSDK1="urn:xmethods-Population"> <Result xsi:type="xsd:float">140,372</Result> </SOAPSDK1:getPopulationResponse> </SOAP-ENV:Body> </SOAP-ENV:Envelope>


text:
Proteomics/Protein Separations - Chromatography

Presentation
Chapter written by: Laura Grell and Alexander Butarbutar Contact llg3875@rit.edu or nbb3924@rit.edu for contributions Chapter modified by Kai Burnett and Dalia Ghoneim Contact kab9783@rit.edu or dxg6098@rit.edu

Introduction

(Res1) To obtain a pure protein sample, a protein must be isolated from all other proteins and cellular components. This can prove to be a difficult task as a single protein often makes up only 1% of the total protein concentration of a cell. Therefore 99% of the protein components of a sample must be removed before it can be classified as pure. A task that is equally challenging is keeping the protein in its active form. When we purify proteins we remove them from their natural environments. As a result, it is necessary to simulate the pH, salt concentration and reducing conditions in which they are normally found. In the process of obtaining an active and pure sample we want to minimize the number of steps taken in order to maximize the yield at the end of the separation. Finally, since proteins are made with the intention of only functioning for a short period of time, it is also critical to obtain our sample as quickly as possible. All these components of protein separations can be successfully achieved by a group of separation methods collectively known as chromatography.

There are several properties of proteins that can be taken advantage of to separate proteins. Different types of chromatography take advantage of different properties. Proteins can be separated by:
 * size
 * shape
 * hydrophobicity
 * affinity to molecules
 * charge

In this chapter several different chromatographic methods will be introduced and described. While the methods outlined below all use different characteristics of proteins to separate proteins from one another, they all utilize an insoluble stationary phase and a mobile phase that passes over it. The mobile phase is commonly a liquid solution. It contains the protein we want to isolate. The stationary phase on the other hand is made up of a grouping of beads, usually based on a carbohydrate or acrylamide derivative, that are bound to ionically charged species, hydrophobic characters, or affinity ligands. Much of the success of chromatography is associated with the selection of an appropriate stationary phase.

In column chromatography, when a protein sample is applied to the column, it equilibrates between the stationary phase and the mobile phase. Depending on the type of chromatography, proteins with certain characteristics will bind to the stationary phase while those lacking the sought characteristics will remain in the mobile phase and pass through the column. For example in ion exchange chromatography, a positively charged protein would bind to a negatively charged stationary phase, while the negatively charge protein will be eluted from the column with the mobile phase. The final step involves displacing the protein from the stationary phase, also known as elution, by introducing a particle which will compete with the protein binding site on the stationary phase. Today various commercial column are readily available, specifically Bio-Rad, Sigma-Aldrich,GE Healthcare and Omnifit offers a wide variety of chromatography column.

The image above is a chromatogram that shows the results of a separation based on signals interpreted by a detector.

tm - the time required for the mobile phase to travel the entire length of the column

tr - the time required for a specific protein to elute from the column

Resources

 * 1) Craig, P. Designing a Separation
 * 2) Florida State University, "Chromatography" Michael Blaber's Biochemistry Lab
 * 3) GE Healthcare - -
 * 4) BioPharm International Guide Basics of Chromatography (2003).
 * 5) Bio-Rad  Chromatography Protein Purification || Green Fluorescent Protein Chromatography Kit
 * 6) BioForum Topics In Chromatography
 * 7) Journal of Chromatographic Science
 * 8) M.Isabel Pedraza Mayer Chromatography Database


text:
XML - Managing Data Exchange/Web Services/Appendix

Appendix
 A .NET Perspective

Now we will create a simple .NET web service using C# and ASP.NET. This web service will provide two methods for it's clients. One will be an adding service and the other will be a subtracting service. Both methods are marked with the [WebMethod] attribute in the following code snippet.

using System; using System.Web; using System.Web.Services; using System.Web.Services.Protocols;

[WebService(Namespace = "http://tempuri.org/")] [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)] public class Service : System.Web.Services.WebService {	#region Construction

/// 	/// Default Construction /// 	public Service {

}

#endregion

#region Operations

/// 	/// Add a values passed in and return the sum. /// 	/// All values to be added together. /// Sum of all values passed in. [WebMethod] public double Add(double numOne, double numTwo) {		return numOne + numTwo; }

/// 	/// Return the difference between numOne and numTow /// 	/// The difference between numOne and numTwo [WebMethod] public double Subtract(double numOne, double numTwo) {		return numOne - numTwo; }

#endregion

}

When executing the web service in a debug mode using Visual Studio 2005, we will get the following screen. Note the two methods available for this web service.

Exhibit 1: .Net

If we click on the add link, we will get the following page.

Exhibit 2: .Net

On this page, we will use the add method and enter our parameters for our web service call. For this example, we will enter 10 as the first number and 5 as the second number. After entering numbers and pressing the invoke button, the client will receive the following XML stream containing the sum value of 15.

 15

Technologies Used  Visual Studio 2005 Beta 2 .NET Framework 2.0 ASP.NET 2.0

The example provided is very simple and does not come close to demonstrating the power of .NET Web Services. For more information on implementing .NET Web Services, please visit http://msdn.microsoft.com/webservices/.


text:
Speech-Language Pathology/Stuttering/Fluency-Shaping Therapy/Motor Learning and Control

Motor learning and control is the study of how our brains execute complex muscle movements. Motor means muscle in this context.

This section will explain how we learn complex, precise movements, eventually perform a skill without even thinking about it. You'll also learn about the role of cognition (mental attention): many of these skills can only be performed when we don't think about them. Our performance degrades when we exert conscious control.

Four Steps from Sensation to Execution
A muscle movement takes about 200 milliseconds (one-fifth of a second) to execute:

 Sensation, or neural transmission from sensory receptors in your eyes, ears, etc., to your brain, takes about 15 milliseconds. Perception, which retrieves long-term memories to organize, classify, and interpret your sensations, takes about 45 milliseconds. In other words, perception changes sensation data into perceived information or meaning. Response selection takes about 75 milliseconds. You use current perception and past experiences to formulate a course or action. For example, in baseball, a batter watches the pitcher and decides whether to swing at a pitch, hit to left field or right, etc. Psychologists differentiate conscious decisions from unconscious translations, or relating a particular stimulus to a particular response. Response execution of an action plan—a step-by-step sequence of events that make up the planned movement—takes about 15 milliseconds. In these events, motor neurons carry signals from the brain or spinal cord to muscles.

Closed-Loop Motor Control
We perform muscle movements with either open-loop or closed-loop motor control.

Closed-loop motor control uses perception to consciously, continuously adjust muscle movements. E.g., threading a needle. You look at the needle. You look at the thread. You move the thread towards the needle. You look at the needle again. You look at the thread again. You correct your movement. You do this dozens of times until the thread is through the needle.

Each stimulus-response adjustment takes at least 200 milliseconds (one-fifth of a second). If you make ten adjustments, the task takes at least two seconds.

Closed-loop motor control has two advantages. It enables precise control, and it enables execution of novel movements (activities you've never done before). E.g., threading a needle on the deck of a rolling ship.

Closed-loop motor control has two disadvantages. It's slow, and it requires your full attention.

Closed-loop motor control is good for learning new skills, or for executing skills you rarely need. But you don't want to use closed-loop motor control for fast-paced, frequently used skills.

Open-Loop Motor Control
200 milliseconds—a split second—may seem fast, but it's too slow for many motor tasks. For example, a gymnast's double-back somersault requires muscle movements lasting only tens of milliseconds.

How is it possible to executes you a muscle movement in tens of milliseconds, when the sensation to execution cycle requires about 200 milliseconds? Simple—don't do the sensation, perception, and response selection stages. Just do the response execution. This final stage of muscle movements can be performed in as little as 15 milliseconds. This is called  open-loop motor control. Open-loop motor control is the execution of preprogrammed movements, called a motor program, without perceptual feedback.

The colloquial term for this is "muscle memory." For example, gymnasts practice hours each day for years, until they can execute complex routines seemingly effortlessly.

After winning the gold medal in gymnastics at the 1984 Olympics, Mary Lou Retton said that coach

Bela [Karolyi] can really teach, I've learned so much from him. Many long hours were spent in the gymnasium…repetition, feedback, repetition, and experimentation. Somehow, after a lot of bumps and bruises, it got easier, as if I could float.

Karolyi added,

Someone should be able to sneak up and drag you out at midnight and push you out on some strange floor, and you should be able to do your entire routine sound asleep in your pajamas. Without a mistake. That's the secret. It's got to be a natural reaction.

Open-loop motor control has two advantages:

 It's fast. You can execute muscle movements in tens of milliseconds. It requires no attention. Movements under open-loop control are automatic and mentally effortless.

Open-loop motor control has three disadvantages:

If your motor program contains errors, you'll execute the errors. You can't stop and adjust a mistake. You may not even be aware that you made a mistake.

Developing open-loop control of a motor skill requires long practice—especially for adults. Children learn some motor skills easily, that adults struggle for years to master.

Novel or new situations can't be handled. E.g., in the 2000 Olympics, officials set the gymnastic vault two inches too low. The officials didn't correct the height until 18 of the 36 women had performed. These 18 athletes performed poorly, eliminating their hopes of winning medals. The American hopeful, Elise Ray, suffered a "devastating fall."

Learning New Motor Skills
Use closed-loop motor control for learning a new motor skill. Then gradually increase your speed until you can perform the motor skill with open-loop motor control.

For example, if you take tennis or golf lessons the coach will have you start with swinging the club or racquet slowly. When you've perfected your form, your coach will have you gradually increase the speed and force, while continuing to use your perfect form. After extensive practice you'll be executing perfect open-loop motor programs. You'll smash the ball hard and fast and accurately without thinking about your elbows or knees or anything other than the ball.

Speech Motor Control
Normal speech uses open-loop motor control:

Speech is fast. Phonemes (speech sounds) are typically 20 to 40 milliseconds.

Speech is complex, requiring coordination of hundreds of muscles to produce sounds.

Speech is automatic and effortless. Speakers think about what they're saying, not about the muscles they're moving.

Fluency shaping stuttering therapy uses closed-loop speech motor control. You consciously relax your breathing. Then, as you exhale, you slowly increase your vocal fold tension, until your vocal folds hum. Then you slowly move your lips, jaw, and tongue to form the sounds of each word. Stuttering is impossible when using closed-loop speech motor control. Stuttering dysfluencies are open-loop speech motor programs.

Closed-loop speech motor control is slow. Closed-loop motor control takes about 200 milliseconds per muscle movement. Open-loop speech sounds are typically in the 20-40 millisecond range. You can see why switching to closed-loop speech motor control slows speech five to ten times, or one or two seconds per syllable.

Closed-loop speech motor control demands your full attention. You must pay attention to your breathing, vocal folds, and lips, jaw, and tongue. This isn't a problem when reading a list of words, but is impossible to use in conversations.

Your speech loses prosody (rhythm and emotional intonation).

Prosody, Parameterization Schema, and Response Selection
Why closed-loop speech motor control loses prosody is an interesting question. A study of television talk show guests found that 94% of what viewers remembered was prosody, or what actors call emoting, or what lawyers call affect. Much—or almost all—meaning is communicated by prosody. Schemata theory suggests that you learn certain invariable characteristics of a motor skill, and you learn certain execution rules or parameterization schema. You then combine the invariable elements with the rules to produce a motor plan. E.g., you could read algebra problems in an angry voice, in a sad voice, and then with the rhythm and emotional intonation of a stand-up comedian.

Accents are another parameterization schema that conveys meaning. For example, a waitress from Oklahoma asked me if I wanted ah-iss. When I figured out that she was asking about ice, I affirmatively answered yay-iss. I knew the invariable characteristics of "yes," and when I'd learned the rules of an Oklahoma accent—e.g., break monosyllabic words into two syllables—I was able to say a word I'd never heard.

In normal speech, we produce prosody through unconscious response selection of parameterization schema. Different environmental cues cause us to select different responses. E.g., you walk into a church and immediately lower your vocal volume. But if no one else is in the church, you could yell "I hate to wear pants!" while turning somersaults down the aisle. OK, that's one of my eccentric hobbies, but most people wouldn't do that.

Another example is a person who grew up in Vermont and Georgia. When she's in New England she speaks in a Yankee accent. When she's in the South she switches to a southern accent. Different environmental cues cause her to unconsciously selects different parameterization schema to produce each accent.

Like prosody and accents, stuttering is a parameterization schema. A stutterer responds to environmental cues to unconsciously select fluent speech parameters or stuttering speech parameters, which are then combined with invariable characteristics of words to produce fluent or stuttered speech. Thus you can treat stuttering by training stutterers to respond differently to environmental cues, or by training stutterers to use fluent speech parameterization schema.

For example, training a stutterer to not feel fear or anxiety when answering the telephone is changing the response selection to an environmental cue (a ringing telephone). In contrast, training a stutterer to speak with relaxed vocal folds changes a speech parameter.

Snake Oil and Charlatans
Closed-loop speech motor control is the "wizard behind the curtain" of many stuttering therapy programs. Switch any stutterer to closed-loop speech motor control and he or she will be nearly fluent.

You can switch to closed-loop speech motor control by making any speech process conscious instead of unconscious. For example, focusing on relaxed, slow breathing will switch you into closed-loop speech motor control, with your vocal folds and articulators (lips, jaw, and tongue) following right along. Or you can focus on producing "gentle onset" with your vocal folds. This will switch your breathing and articulators to closed-loop speech motor control. Or you can focus on "reduced articulatory pressure" and your breathing and vocal folds will follow.

Always these "wizards" claim that their therapies are 100% effective if the stutterer "really tries," that is, if he devotes his full attention to closed-loop speech motor control. If he instead pays attention to a conversation, switches into open-loop speech motor control, and then stutters, then he wasn't "really trying."

And the closed-loop speech motor control effect has caused speech-language pathologists to hypothesize various theories that stutterers have something wrong with their breathing, or with their vocal folds, or with their articulators, or even that stutterers' brains are slow in some way. That's like saying that student drivers have slower brains than Indy 500 race car drivers because student drivers are safe at 20 mph but crash when driving at 200 mph. Everyone performs slowly when attentively learning a new motor skill. For stutterers in speech therapy, the new motor skill is fluent speech.

Some speech clinics tell stutterers that they'll always have to speak slowly. That's like training a student driver to drive 20 mph, then telling him never to go faster.

Slow Speech Is Not the Goal of Stuttering Therapy
If you learn tennis or golf, you'll use closed-loop motor control when you're learning to swing the club or racquet. As you practice, increasing your speed and force, you'll gradually reinforce open-loop motor programs.

Similarly, you'll use closed-loop speech motor control when working with your speech-language pathologist. She'll train you to move your respiration muscles, vocal folds, and articulators correctly to produce fluent speech. When you've mastered this at a very slow speaking rate, she'll help you to gradually increase your speaking rate, while staying fluent. The goal is fluent, automatic, effortless, normal-sounding and normal-rate speech. Slow speech is not the goal of stuttering therapy.

Severe stutterers usually don't mind learning closed-loop speech motor control. If your stuttered speech is ten to twenty times slower than normal speech, then closed-loop speech motor control, which is typically five to ten times slower than normal speech, will double your speaking rate. Some severe stutterers are even willing to use closed-loop speech motor control outside of the speech clinic. Record conversations with and without using closed-loop speech motor control. Count your syllables per second. You may find that closed-loop speech motor control feels slower but is actually faster than your stuttered speech.

But mild stutterers don't like closed-loop speech motor control. They can hide their stuttering by avoidance and substitution (of certain sounds, words, or speaking situations). They can sound fluent at a normal speaking rate. They don't like that closed-loop speech motor control "advertises to the world" that they have a speech disorder. If they're embarrassed to admit that they stutter, they won't want to use closed-loop speech motor control.

Mild stutterers should consider that closed-loop speech motor control enables them to say anything they want. E.g., a mild stutterer wants to buy a chess set. He's afraid of s words, so he calls a toy store and asks if they have "one of those games with kings and knights and castles."

The puzzled clerk responds that the store has many games with kings and castles and knights. After five minutes of conversation, the clerk asks, "Do you mean chess sets?" The stutterer says yes. The clerk never knows that the caller is a stutterer, but she thinks the caller is an idiot. The stutterer wasted five minutes because he wasn't willing to use ten seconds of slow speech.

Or the stutterer drives to the store and looks for a chess set, without calling first. If the store doesn't have chess sets he wastes an hour, to save ten seconds.

In other words, saying what you want slowly is faster than saying something else, or not speaking.

Analogy to Touchtyping
I've never taken a typing class. I type about 45 words per minute (I'm probably the world's fastest two-fingered typist!).

I've twice tried to learn touchtyping. My speed dropped to less than ten words per minute. Touchtyping not only slowed me down, it required my full concentration. I couldn't think about what I was writing, only about moving my fingers.

I gave up touchtyping within a week. If I'd kept at it, my speed would have increased and eventually surpassed my two-fingered typing speed. I might have been typing 80 words per minute now. The mental effort would have diminished, until touchtyping was automatic and effortless.

Coaches say they'd rather work with a novice who has never played their sport, rather than with an experienced player who uses incorrect techniques. It's easier to learn a new motor skill correctly than it is to correct an incorrect, deeply learned motor skill.

Stuttering is difficult to overcome because we learned to talk incorrectly. We have to learn new, fluent speech motor skills, and we have to not use our old, dysfluent speech motor skills. We learned these dysfluent speech motor skills in childhood, when our brains were growing. Now the dysfluent speech motor skills are hardwired into our brains. Making fluent speech automatic and effortless, for a stutterer, demands more time and effort than learning a new sport or vocational skill.

Using DAF to Slow Speaking Rate
Many speech clinics use delayed auditory feedback (DAF) devices to establish fluency using closed-loop speech motor control. With only a little training a DAF device can help a stutterer maintain perfectly paced, steady, mentally effortless, slow closed-loop speech motor control.

The user's speaking rate can be adjusted by turning a knob. A typical protocol is to train a stutterer to use closed-loop speech motor control with a 200-millisecond delay and one to two seconds per syllable. The stutterer practices this until he is 100% fluent. That usually takes only one or two therapy sessions. (A study found that without training a 195-millisecond delay reduced stuttering only 85%.)

When the stutterer can speak 100% fluently, the speech-language pathologist then has the stutterer use one- or two-second stretched syllables without the DAF device; in increasingly stressful situations (e.g., calling the speech-language pathologist's answering machine); and with the DAF device adjusted for faster speaking rates. The stutterer must stay on-target with 100% fluency, or go back to using the DAF device at 200 milliseconds and a one- to two-second speaking rate.

Typically, a 100-millisecond DAF delay is used with half-second per syllable stretched speech, a 75-millisecond delay is used with quarter-second per syllable "slow normal" speech, and a 50-millisecond delay is used with a normal speaking rate.

Three Stages of Motor Learning
We learn new motor skills in three stages:

In the cognitive stage, you observe the target motor skill. For example, your speech-language pathologist demonstrates relaxed breathing.

In the associative stage, you learn to perform and refine the motor skill. You perform the movements under closed-loop control.

In the autonomous stage, the motor skill becomes automatic. You perform the muscle movements without mental effort. You perform the movements under open-loop control.

Let's go back to the golf or tennis coach example. You watch the coach hit a few practice balls. Then the coach hands you the club or racket. The coach guides you through a swing, telling you to drop this shoulder or extend that forearm. Soon you can execute the swing perfectly, if you fully concentrate on each movement. You then practice the swing, and your game improves.

A few years later a novice admires your excellent swing and asks you to explain how you do it. "I don't know," you say, "I just do it without thinking about it."

For another example, last summer I tried mountain bike racing. In four races I crashed four times. Then I hired a coach. In twelve hours over three weeks, he taught me how to ride down hills; make tight turns; jump my bike over logs; climb hills; plus a few tricks such as picking up a water bottle off the ground.

Then I quit mountain bike racing. I'd completed the associative stage and learned how to do each skill. Now I would have to practice these skills hours a day, several times a week for years to make the skills automatic in the fast, high-stress environment of racing. I.e., I could do any of the skills if I thought about it, but my body didn't automatically execute the moves without conscious mental effort. I decided that mountain bike racing isn't important enough to me to spend thousands of hours practicing.

Stuttering therapy follows a similar course. A speech-language pathologist can show you the fluency skills—relaxed, diaphragmatic breathing; vocal fold relaxation (gentle onsets); and relaxed articulation muscles (lips, jaw, and tongue)—in a few minutes. Teaching you to execute these skills takes a few hours. You can then speak fluently in the speech clinic, when you mentally concentrate on each skill. Almost everyone successfully completes these cognitive and associative stages.

You then have to practice these skills thousands of hours to make them automatic and effortless, in high-stress situations. Many stutterers fail at this stage. But no one intentionally fails for the reasons I quit mountain bike racing. No one rationally weighs the alternatives and says, "Talking isn't important to me. I'll learn sign language instead, or write notes."

Instead, stutterers fail at the autonomous stage because speech clinics don't train this well. Speech clinics call this transfer. Perhaps your speech-language pathologist takes you to a shopping mall for a few hours. But the autonomous stage requires thousands of hours of conversations, including high-stress conversations. Stutterers habitually avoid such conversations. You may find that the skills you learned in the low-stress speech clinic fail in high-stress conversations. Your therapy progress begins to fail. You revert to old habits and avoidances. Your stuttering returns.

Recommended Books

 * Motor Control and Learning: A Behavioral Emphasis, by Richard Schmidt, Tim Lee (2005; ISBN 073604258X)


text:
Handbook of Descriptive Statistics/Introduction

A distribution is a collection of measurements of a single phenomenon. If the number of responses is small, just listing them all may be adequate description. In this case, no summarization or data reduction is needed. However, if the number of measurements is large, a full list may fail as a communication or analysis tool.

Happily, distributions can be summarized. Some summaries are very brief and provide just a little description. For instance, the mean is a one number summary that captures just one aspect of a set of numbers. There are six aspects of a distribution that may warrant consideration when summarizing.

Sample size
The number of subjects or items measured is often of fundamental interest. For instance, we might be examing a distribution of the heights of college students containing measurements on 1,234 subjects.

Scale and precision
The type of data you are dealing with (continuous, categorical, ordinal, etc.) influences many of the choices you must make about how to describe and analyze your data. The units of measure (inches, kilos, %, mmol, drachmas per acre of corn, etc.) should be noted. For our example, the data were recorded in inches to the nearest 0.1 inch. In other words, measurements were rounded to the nearest tenth of an inch before recording. For categorical data, the "scale" is just the names of the categories. If we also recorded the gender of the students, we might have three categories: "Male," "Female" and "Unknown."

Central tendency
Along the scale, about where do the data lie? Theoretically, adult human height is measured on a scale that goes on to infinity. However, most of the measurements we will observe center around a value of 68 inches (5'-8"). There are a large variety of ways to describe the central tendency. For continuous data, the mean (or average) is often calculated. But the mean has limitations and other measures of central tendency are useful: median, geometric mean, mode, etc.

Spread
Central tendency tell you where the data tend to be, but not all of the data will have the same value. Usually, some will be higher and some will be lower. The college students have heights that lie between about four feet (48 inches) and about 7 feet (84 inches). The spread in the data can be summarized in many ways: range, variance, standard deviation, inter-quartile range, etc.

Shape
Shape is the richest aspect of the distribution and often the most difficult to summarize. For many measurements, the bulk of the data occur at the middle and the number of observations tails off at higher and lower values. The classic normal distribution is one such distribution: it has a "bell-shape." If all the values in the range of data occur about as often as each other, then the shape is said to be "uniform" or "rectangular." If all the data tend to be at one end of the range, with a declining number of cases observed at the other, the distibution is said to be "skewed."

There are numerical methods for describing the shape of a distribution. For instance, the degree of skew can be calculated and reported. However, often the best way to describe the shape is to draw a picture of the data such as a histogram.

Outliers
Often, a small number of observations have values substantially above or below the bulk of the data. These outliers are sometimes disturbing or confusing, but they can be very, very, important. The best way to summarize outliers is often just to note them individually or highlight them in the graphical description.


text:
Wikibooks talk:Templates/Stubs

Guidelines for Stub Subcategories
Going through the main stub category, and starting to roll some of them off into seperate stub categories, I feel the need to start a discussion on some guidelines for using these. Right now, I can see two main issues that need to be resolved.

Naming of Stub Subcategories
Currently, the naming is all over the place. There are 3 conventions curretly in use: Kernigh suggested in IRC that the first type has the potential to clutter namespaces, and recommends the third convention:
 * 1) Category:Bookname:Stub(s)
 * 2) Category:Bookname Stub(s)
 * 3) Category:Bookname/Stub(s)

[21 March 17:00:48] Kernigh: I usually call my templates [21 March 17:01:02] Kernigh: In the past, I used, but then I decided that was confusing with namespaces. [21 March 17:01:14] Kernigh: For example, would not be in the Template namespace.

It also fits in nicely with current general category convention (to use Category:Typeofmodule/Subcategory) and keeps things clean.

There's no need to rush and change old categories, but this is something I'd like to see a general consensus on before I go and clean up Category:Stubs.

Creation of Subcategories
There's also the question of how many stubs are necessary before a subcategory is necessary. I don't expect any strict guideline or policy to come out of this section, because it's a highly subjective and situation-specific matter: A larger, but non-complete book with only one stub/sectionstub might still warrant a category due to possible future expansion of the book. Something like the Cookbook may require classes of stubs: Recipe Stubs, Ingredient Stubs, and so on. Smaller books might need to be classified by bookshelf or general subject areas, such as smaller How-To books.

In any case, I'd like to receive some feedback on this before I begin the process of cleaning up Category:Stubs. (It should also be noted that some of the modules in there are about to go up for a VFD as soon as I get the necessary links organised.) Xerol Oplan 00:21, 22 March 2006 (UTC)

 * I'm hoping that we can clean up some of these stubs before they get out of control! I guess this is a sign that Wikibooks is growing, that this sort of question even has to be raised.  Most of this IMHO is something that should be in the hands of the participants of each Wikibook, being considered as a seperate Wikiproject (as it would be traditionally defined on Wikipedia for a group of such pages).  The stub organization is something to help those authors try to coordinate their efforts and try to do general cleanup.  My writing style is that I tend to work on just one module at a time and then move on, but not everybody seems to work that way, nor is it in the nature of some of the Wikibooks either.  Some books simply seem to be just a maze of hundreds of stubs, because it is easy to add some initial details, but harder to really work out each module completely.

 * Categories can have hundreds or even thousands of pages in them, so the only point of "sub cats" in this regard is to help break up the groupings of stubs into smaller amounts that are more easily dealt with, aka for individual Wikibooks or similar themes like Computer Programming books. If a particular group of editors wants to create a subcat for their Wikibook but only has one stub, I say go for it.  On the other hand I think it would be more useful if there were at least 10-30 stubs before "outsiders" really went in and explicitly created new sub-cats.  I don't know how subjective that seems, but it is something to consider.  For sub-cats of a particular Wikibook, that should be something explicitly done by major contributors to that Wikibook.

 * You might also want to consider breaking up stubs by bookshelf. That is at least a level of organization here on Wikibooks that makes sense, and something that can be tied directly to the bookshelf page as well.  --Rob Horning 00:59, 22 March 2006 (UTC)

 * Good idea. As the stubs category has only gotten larger, and will cotinue to do so, would anyone mind if I divide the stub category into bookshelves? --haginძaz 02:38, 24 May 2006 (UTC)

 * I don't mind at all, that's probably a good idea, considering that every single book has the potential to include a stub category. I'm going to go through, and rename most of the stub subcategories that i've created to use the "Category:Bookname/Stubs" format, because that makes the most sense. --Whiteknight (talk) (projects) 22:46, 7 July 2006 (UTC)

I went through Category:Stubs, and fixed all the subcategories that I am associated with, to use the "forward slash" convention, as noted here. --Whiteknight (talk) (projects) 22:59, 9 July 2006 (UTC)

Stub Deletion Policy
I think the time has come for some serious discussion take place over the status of stubs here on Wikibooks. The unofficial policy up until now has been to keep stubs, under the philosophy that at some point in the future somebody will come along and hate the stub so much that they will try to rework the content and turn it into a real Wikibook. This policy seems to have been very useful on Wikipedia, but the circumstances on Wikibooks are a little bit different.

One issue here is to even determine what exactly is a stub. One or two sentances or a short paragraph is a reasonable use of the term, as is a page full of red links with at most one or two "sub pages" that have been started, each of which is only a paragraph in length. Obviously other stub definitions can be added as well.

And this is a Wikibook stub by using this definition. Module stubs within a specific Wikibook that is otherwise under active development should be a completely seperate issue, and have its own page culling guidelines.

If stubs violate WB:WIN in terms of the likely direction of completed content, current policies cover what should happen with them and a VfD is certainly useful. For other modules, this is where the discussion really needs to go. Should a stub be able to languish on Wikibooks for several years (as a couple have already) or should there be a reasonable period of time (I'm talking years here, not weeks) that a Wikibook should be worked on or be deleted?

Under no condition should modules or Wikibooks stubs be deleted that have been recently created. This is not showing good faith to whomever is trying to develop the content, and there may be a group collaboration effort going on that an administrator may not be aware of. Any other thoughts? --Rob Horning 13:05, 22 March 2006 (UTC)

 * I agree that the problem is in defining a stub; just from looking through Category:Stubs it seems that some of these might've gone up for a speedy delete, depending on who saw the module first. (Specifically looking at the cases of 68.73.54.217, there's another issue at hand there, but this is a case I'm currently preparing to bring up on VfD.) Some of the stubs in the root may have been intended as being brought up as submodules of a book, but due to bad link preparation weren't linked as such, so checking the incoming links could help, and the stub could probably be moved to a subpage of the main book and recategorised as a stub under that book.

 * Another problem is the misuse of the templates; I found at least five cases where sectstub should have been used, but stub was used instead. This makes the stubs category (along with stubs that are part of a larger book) look a lot larger than it actually should be. I also found a couple that were marked as stubs, but are actually TOCs to books, some of which had a lot of well-filled modules. So it really needs to be looked at on a case-by-case basis, but I think a lot of these modules might be up for deletion anyway, simply for being "sub-stubs". Xerol Oplan 21:31, 22 March 2006 (UTC)

 * In the past, everyone always used stub. It was not until my redesign of 30 November 2005 when sectstub added pages to a category. Even after that, because current books use stub much more often, some editors know not of sectstub. --Kernigh 20:30, 25 March 2006 (UTC)

 * I'm not convined that every three-sentence stub should be discussed at VfD in order to be deleted. I think that stubs containing no useful content (like "this is a part of XYZ book", "second law of thermodynamics will be explained here", "see also: [link] [link] [link]") should be speedy deleted. New stubs having some content should be kept but old ones (about two years old) having only table of contents with red links should be massively submitted to VfD. Stubs that should be specially targetted are those which do not explain what they should contain (like Energy Efficiency). --Derbeth talk 16:31, 10 April 2006 (UTC)

Categories on this page...
Why is this page put into so many categories? -- SB_Johnny | talk 16:07, 10 August 2006 (UTC)
 * It's a side-effect of displaying the stub templates (which place the page they're used on into a category) on the page, in the same way Template messages/Deletion appears on Category:Candidates for speedy deletion, because the template is used on the page. —The preceding unsigned comment was added by Xerol (talk • contribs).

title: Wikibooks talk:Templates/Stubs


text: User talk:71.212.44.44

title: User talk:71.212.44.44


text:
Speech-Language Pathology/Stuttering/Fluency-Shaping Therapy/Fluency-Shaping Techniques

Fluency shaping therapy programs typically begin with slow speech with stretched vowels, then work on relaxed, diaphragmatic breathing, then work on vocal fold awareness and control, and finally work on relaxed articulation (lips, jaw, and tongue).

These techniques are all abnormal. They all produce "weird"-sounding speech. The idea is to go to extremes when practicing (in the speech clinic or at home), and then in "real world" conversations you reduce the techniques so that you sound normal, and speak fluently.

Slow Speech with Stretched Vowels
Slow speech enables you to learn the other fluency skills. The goal is not to use slow speech in every conversation for the rest of your life. Like a novice golfer, you learn the correct forms and muscle movements slowly at first. Then, as you master these muscle movements gradually increase your speed. See the section Slow Speech Is Not the Goal of Stuttering Therapy.

Let's start with how not to do slow speech with stretched vowels:

"I" "am" "an" "American."

Saying "I am an American" normally takes about 1.5 seconds (seven syllables at about five syllables per second). By silently pausing two seconds between words, and saying each word normally, the phrase would take about eight seconds. That would not improve your fluency.

Instead, stretch each vowel for a second or two. Also stretch voiced consonants (e.g., /m/, /n/, /r/) a little longer then normal, but not as long as vowels. Articulate voiceless consonants (e.g., /k/) lightly and quickly, just touching your lips or tongue and then moving to the next voiced sound.

Join the syllables together, with no breaks or pauses between words. The result should sound like (where each letter is one-fifth of a second):

"IIIIIIIIIIaaaaaaammmaaaaaaannnAAAAAAAmmmeeeeeeerrriiiiiiiiiikaaaaaaannn."

Be sure that each syllable is held equally. In other words, "American" should take four times longer to say than "I." Don't make "American" the same length as "I."

Should you hold each syllable for one second or for two seconds? Some speech clinics start with one-second stretched syllables, when other speech clinics start with two seconds per syllable. No research has investigated which is more effective. If you are 100% fluent at one second per syllable, then that is slow enough. But if you're not 100% fluent at one second per syllable, use two seconds per syllable. According to motor learning theory, you need to move slow enough that your form is perfect, but there's no reason to move slower.

Use a stopwatch to check that each syllable is the same length.

If you have a DAF device, set the delay to 200 milliseconds. Then hold each syllable until you hear yourself in the headphones. Check your stopwatch and you should see that each syllable is between one and two seconds.

Relaxed Breathing
Place one hand on your stomach. Breathe so that your hand moves out when you inhale, and in when you exhale.

Notice that you're taking many small breaths. Your inhalation and exhalation are equal in time duration.

This is called relaxed or diaphragmatic breathing. Many people breathe this way.

Now switch to upper-chest breathing or thoracic breathing. Take a big breath, using your upper chest muscles to expand your lungs. Release the air slowly, while maintaining this upper chest muscle tension to hold air in your lungs as long as possible. When you've released the air, quickly take another breath, filling your lungs as rapidly as possible.

Practice switching between thoracic and diaphragmatic breathing.

Thoracic breathing increases our lung capacity. It enables us to maximize our physical exertion. Our "fight or flight" instinct switches us to thoracic breathing. We're then better able to run or fight.

Some individuals hyperventilate or switch to thoracic breathing when experiencing non-physical stress. Stress reduction classes help students learn to relax by consciously switching to diaphragmatic breathing.

Thoracic vs. Diaphragmatic Breathing

We also use thoracic breathing when talking. A large breath with a long, slow exhale enable us to speak many words before pausing for another breath.

Well-meaning people who know nothing about stuttering may tell you to "take a deep breath" before talking. But the opposite is better advice. Diaphragmatic breathing is the foundation of many stuttering therapy programs. Taking smaller breaths with your diaphragm can help you relax and may help you speak more fluently.

Try it. Using relaxed breathing will relax your entire body. Most importantly, it will relax your vocal folds, and then your lips, jaw, and tongue. Your voice will deepen and sound confident - maybe even "sexy." You'll feel relaxed and confident.

Practice a word list using diaphragmatic breathing. Read a magazine page aloud using diaphragmatic breathing.

You'll soon discover a few problems trying to speak with diaphragmatic breathing. Each breath is small, so you're able to say only a few words on each breath. Inhalation and exhalation time lengths are equal, so you will speak in shorter phrases that are produced between longer pauses. You're less able to speak loudly.

As with other fluency-enhancing speech motor techniques, speaking with diaphragmatic breathing is somewhat abnormal, but can also be useful. Include speaking with diaphragmatic breathing in your stuttering therapy practice exercises. Mastering this skill has helped many speak short phrases fluently during stressful situations (e.g., when a police officer pulls you over for speeding!) You may not need to say much besides, "Yes, officer," and "No, officer."

And as you master speaking with diaphragmatic breathing, you'll develop something in between thoracic and diaphragmatic breathing. This "in between" breathing will be more relaxed than thoracic breathing, yet your phrase length and vocal volume will be within the normal range.

Phonation
Your vocal folds are flaps of muscle in your throat. Making your vocal folds vibrate produces sound. This sound then becomes your voice. Vocal fold vibration is called phonation.

Two conditions produce phonation. First, you release air from your lungs. Next, you tension or tighten your vocal folds.

Place your fingers on your throat. Exhale and hum. Your fingers should feel a vibration. This is your vocal folds vibrating.

Stop humming, and feel the vibration stop. Practice switching your phonation on and off.

Now vary your phonation in two ways. Change your volume by humming louder, then quieter. Change your pitch by humming up and down a musical scale.

How did you do that? You varied your volume of exhalation, i.e., you increased or decreased the air releasing from your lungs by tensing or relaxing your thoracic (upper chest) muscles. More exhalation enabled you to produce more volume.

You also varied your vocal fold tension. Tense vocal folds produce a higher-pitched voice. Relaxed vocal folds produce a deeper or lower-pitched voice.

Tense your vocal folds as hard as you can. You'll completely block your throat, not allowing any air to escape. If you take a deep breath and then block your throat, your increased lung pressure makes your chest stronger. Like inflating a tire to carry a heavier load, this is effective for lifting a heavy weight. But it's not a good way to talk!

Practice one more aspect of phonation. Take a breath and hold it, tense your vocal folds, then release air. Switch to the other way: take a breath, release a little air, then tense your vocal folds. Note that the former produced a croak. The latter produced a nice hum. This shows that phonation requires timing two muscle movements: exhaling a little air, and then starting to tense your vocal folds.

You now see that three things can go wrong with phonation:

 Releasing too much or too little air (inadequate breath support). Overtensing your vocal folds. Under stress, you may try too hard to talk, tense your vocal folds too much, and block off air flow. This results in a silent block. Mistiming exhalation and vocal fold tension. A goal of stuttering therapy is train the stutterer to consciously take a breath, release a little air, gently tense his vocal folds, and then begin to talk. This exercise is called gentle onset or easy onset.

Gentle Onsets with Vowels
To hit a baseball home run, you use all of your arm muscle strength. In contrast, to putt a golf ball a few feet, your arm muscles are more relaxed than tense. Phonation is like putting a golf ball, not like hitting a home run.

To use gentle onsets (also called easy onsets), take a relaxed breath with your diaphragm. Release a little air. Make an ah sound as you gradually increase your vocal fold tension. Feel your vocal folds begin to vibrate. Increase your vocal fold tension, until you reach normal speaking volume. Gradually reduce vocal fold tension, until you reach silence. Time this to take about two seconds. You should be able to do this on one breath, without reaching residual air.

If you were to see your vocal volume charted, it would look like this:

You can use a computer application that displays your phonation contour on the screen.

Practice fifteen gentle onsets with the fifteen vowel sounds (say the vowel, not the word):

Front Vowels:  long e, as in beet short i, as in bit long a, as in bait short e, as in bet

short a, as in at

Back Vowels:

long u, as in boot

short o, as in book

long o, as in boat

aw, as in cause

ah, as in cot

Central Vowels:

ow, as in about

short u, as in but

Dipthongs:

long i, as in bite

oy, as in boy

au, as in bough

Gentle Onsets with Words

Gentle Onset with Words

Now say "dog," stretched over two seconds, with gentle onset. Begin with a quiet, gentle /d/ sound. Switch to the /aw/ vowel sound and gradually increase vocal volume. After one second, gradually reduce vocal volume. Switch to the /g/ sound, and stop vocal fold vibration.

Voice and Voiceless Consonants

All vowels use phonation. Some consonants use phonation, i.e., are voiced. Other consonants are produced without phonation, i.e., are voiceless. You can whisper these consonants.

Place your fingers on your throat. Say ah to feel your vocal folds vibrating. Say the following words and decide whether the initial consonant is voice or voiceless:

The first column was voiceless. The second column was voiced.

Did you notice that these sounds were pairs? /h/ and /w/ have your lips, jaw, and tongue in the same positions. The difference is that your vocal folds vibrate to produce /w/, but don't vibrate to produce /h/.

To say a word with voiceless consonant, take a breath, let out a little air, shape the consonant with your lips, jaw, and tongue, then switch to the vowel and gently start your vocal fold vibration.

Practice a word list. Keep your fingers on your throat to feel your vocal folds switching on and off as you go from voiced to voiceless sounds. Stretch each word to two seconds.

Because most words contain both voiced and voiceless sounds, we switch our vocal folds on and off many times each second while talking. A core behavior of stuttering is an inability to switch phonation on at the right moments. The timing can be as precise as one one-hundredth (1/100) of a second.

Normal speech is about five syllables per second, or 0.2 seconds per syllable. For this practice you're using two seconds per syllable stretched speech, or ten times slower than a normal speaking rate. Slowing down your speech helps you develop awareness and control of speech elements that are otherwise too fast to notice or control. If you play a sport, such as tennis or golf, your coach might videotape your swing and then replay it back in slow motion. This improves your awareness and control of the motor skill.

Continuous Phonation

Stuttering therapy sometimes teaches techniques that produce fluency, but sound abnormal. E.g., speech with diaphragmatic breathing produces fluency, but shortens phrase length and makes you pause between phrases. The immediate goal is to use these techniques to produce fluent speech, and over time reduce the degree of exaggeration, until your speech sounds normal. Another goal is have a "trick" to use in stressful situations, such as speaking to a police officer.

Continuous phonation is such a technique or trick. Recall that consonants come in voiced/voiceless pairs. Simple substitute a voiced consonant whenever you need to say a voiceless consonant.

E.g., "Patty" becomes "Baddy." Say each word slowly, with your fingers on your throat to feel your phonation. You'll feel your vocal folds switch on and off for "Patty," but stay on for "Baddy."

If you shorten the consonants and stretch your vowels (producing a slower speaking rate), listeners won't hear the difference between "Patty" and "Baddy."

Gentle Onsets with Multisyllabic Words

Practice using a gentle onset on each syllable. Go loud on each vowel. On the consonants, relax, go quiet, and lightly and quickly articulate the sounds. E.g., on "American," you start with a gentle onset on the initial /uh/. Open your mouth wide at the loudest point in the phonation contour.

Take the /uh/ sound down in volume, while at the same time closing your mouth to articulate the voiced /m/. Bring the /eh/ sound up in volume. Again, open your mouth wide at the loudest point in the phonation contour.

Take the /eh/ sound down in volume, while at the same time reduce your jaw opening (but don’t close your lips) to articulate the voiced /r/.

Open your mouth wide again for the /ih/ vowel on the third syllable.

Now you get to the only voiceless sound in "American." Before the /k/ sound, take the down the volume of the /ih/ vowel. Whisper the /k/. If you block, you dropped the /ih/ volume too fast. Try again with a long, slow decline in volume on the /ih/. Articulate the /k/ lightly, for just a moment.

If you still block on the /k/, change it to a voiced /g/. In other words, say "Amerigan."

Use another gentle onset on the final /eh/ vowel. Reduce your volume on the final voiced /n/ consonant.

The result is an abnormal-sounding "sing-song" speech pattern. Your jaw opens and closes noticeably on each syllable. While you won’t want to talk like this for the rest of your life, for practice or in stressful situations this technique helps you use gentle onsets, continuous phonation, and a slower speaking rate.

Reduced Articulatory Pressure
The third set of speech muscles (after respiration and phonation) are your articulators: lips, jaw, and tongue. These muscles form your vocal fold humming into sounds and words. If you phonate without moving your lips, jaw, and tongue, all that comes out of your mouth is humming. The goal of this last target is to relax these muscles.

Reduced articulatory pressure is also called "soft targets."

Lightly touch your tongue for the /t/. Lightly close your lips for the /b/. Keep your speech production muscles relaxed for all sounds.

The wrong way is to tense your lips and tongue and jaw too much, and hold this tension too long.

You've learned to stretch and emphasize vowels. Now work on de-emphasizing consonants. If you stretch and emphasize vowels, and de-emphasize consonants, you should be able to speak fluently.

Read another word list aloud. Feel how your lips, jaw, and tongue move to change sounds. Say each word with normal articulation tension. Then say the word again with tense articulation. Then say the word again with relaxed articulation.

This section is short because most stutterers can easily do the reduced articulation target with little or no training. There's no need to include pages and pages of diagrams showing the correct positions of the lips, jaw, and tongue for each of the 40+ sounds of English. Most stutterers know the correct positions to produce sounds, we just have to do it with less force.

However, if you speak with a foreign accent, or if you have an articulation disorder (e.g., lisping), you may want to do articulation therapy along with stuttering therapy. Articulation therapy will train you to place your lips, jaw, and tongue in the correct positions.


text:
Talk:Handbook of Descriptive Statistics/Introduction

Here is my approach to teaching descriptive statistics. If this is not the right place for this material, where should it go? Littenberg 00:44, 22 March 2006 (UTC)


text:
User talk:71.33.5.74

Hi. Can you please stop deleting from the Star Sonata book? If you edit the Sandbox, you will not need to worry about disrupting the book. --Kernigh 01:08, 22 March 2006 (UTC)

title: User talk:71.33.5.74


text: Template:Engineering Acoustics

title: Template:Engineering Acoustics


text:
Engineering Acoustics/Authors

Students in ME 513: Engineering Acoustics started this Wikibook, Engineering Acoustics, during the fall semester 2005. Some pages of this book contain author credits.

Since then, other and anonymous users have contributed to this book.

title: Engineering Acoustics/Authors


text:
Adventist Youth Honors Answer Book/Nature/Bats

1. Why are bats classified as mammals and not birds?
Here are some identifiers for mammals, birds, and bats. After examining the list, it should be rather obvious how much more like mammals bats are compared to birds:

Mammals:
 * Fur
 * Bear live young (except platypus)
 * The babies nurse from their mother
 * They are Warm-blooded
 * Four legs often with toes and/or "hands" and "feet"

Bats:
 * They have fur or hair
 * A baby bat is born alive
 * The babies nurse from their mother
 * They are Warm-blooded
 * Bats have arms, hands and feet

Birds:
 * Birds have feathers, not fur or hair
 * They are hatched from eggs
 * The babies are fed from mom's mouth
 * They have wings, but not hands and fingers

2. What is the main characteristic that separates bats from all other mammals?
Bats are the only mammal that can truly fly (others species such as the flying squirrels actually glide instead of fly).

3. What is the name of the order that bats belong to and what does it mean?
Bats are in the order Chiroptera, which literally means "hand-wing" in Latin. This name makes sense because a bat's wings stretch over the forearm and fingers, and attach down at the ankle bones. The name is from the Greek, Cheir=hand; Pteron=wing. They got this name when scientists noticed that they fly with a modified hand.

4. What are the largest and smallest bats and where do they live?

 * Largest: The biggest flying mammals are the Flying Foxes, particularly those living in Asia and Australia. Several species have a length of 45 cm (17.7 in), a wingspan of 1.7 m (5 ft 7 in), and a weight of 1.6 kg (3.5 lb). The Indian Flying Fox in particular has been known to attain a wingspan of 6 feet.
 * Smallest: The world's smallest bat is the Kitti's Hog-Nosed Bat (a.k.a. The Bumblebee Bat) of Thailand. Weighing less than a penny and with a wingspan of less than 5 inches it is also the worlds smallest mammal.

5. How many different types of bats are there worldwide?
There are approximately 1000 species of bats in the world, and bats live on every continent except Antarctica. There are approximately 825 species of Micro-chiroptera worldwide, and about 175 species of Mega-chiroptera.

6. Bats are divided into two (2) suborders. What are their names?

 * a. Mega-chiroptera
 * b. Micro-chiroptera

7. Which suborder of bats uses echolocation and which suborder uses eyesight to find their food?

 * a. Megabats: Use eyesight.
 * b. Microbats: Use echolocation. (Bats send out sound waves using their mouth or nose.  When the sound hits an object an echo comes back.  The bat can identify an object by the sound of the echo. They can even tell the size, shape and texture of  a tiny insect from its echo.  Most bats use echolocation to navigate in the dark and find food.)

8. What is the diet of the Megabats?
Many megabats eat fruit, nectar, and pollen, which earns them their nickname, "fruit bats".

9. What is the diet of the Microbats?
The microbats are generally insect-eating, although they tend to have a much more varied diet than the megabats. Besides Insects, microbats eat anything from nectar and fruit like megabats, fish, small mammals and birds, and even blood.

10. How many babies does a bat have each year and what are the babies called?
Most bats have one baby per year, though some have twins or triplets. Baby bats are called pups.

11. Find three Bible texts that mention bats.
Leviticus 11:19: The stork, any kind of heron, the hoopoe and the bat.

Deuteronomy 14:18: The stork, any kind of heron, the hoopoe and the bat.

Isaiah 2:20: In that day men will throw away to the rodents and bats their idols of silver and idols of gold, which they made to worship.

Which text uses bats in an end-time prophecy?
Isaiah 2:20: In that day men will throw away to the rodents and bats their idols of silver and idols of gold, which they made to worship.

12. Do bats hibernate or migrate for the winter?
In the cold climates bats either hibernate or migrate to warmer locations. Bats living in the tropical zones stay active year round.

13. Name the parts of a bat.
Knee, tail membrane, tail, calcar, foot, wing membrane, fingers, wrist, ear, tragus, forearm, thumb.

The calcar is a bony structure connecting the leg to the tail. The tragus is a feature bats have in common with humans, being the fleshy part of the ear above the lobe and next to the temple.

14. How many insects can a bat eat in an hour?
600 - 1,000 insects per hour according to their body weight. A single brown bat can eat 1,200 insects per hour.

15. What are the two (2) main benefits bats provide for man?

 * a. Eat insects. A single brown bat can eat 1,200 insects per hour (3,000 - 7,000 per night). Bats eat such harmful insects as cockroaches, mosquitoes, and gnats. Large colonies of bats can consume many insects that would otherwise harm farmers' crops.
 * b. Pollinate and spread seeds. Bats serve as food plant pollinators.
 * c. Provide outlet for medical research. Their echolocation skills have been studied to help medical professionals help the blind. A chemical agent in the saliva of the common vampire bat, Draculin, is being tested for use in helping stroke victims.

16. Build or purchase a bat box, know the best place to put it and install it at a home, church, or your school. Record for 3 months what kind and how many bats have made it their home.
You can find online plans to build your own bat house here: https://web.archive.org/web/20150111115645/https://www.batcon.org/index.php/resources/for-specific-issues/artificial-roosts

For best results, the roosting chamber should be at least 50 cm (20 in) wide, 70 cm (24 in) high, and about 2 cm (3/4 in) deep on the inside. It should have an open bottom and a roof. The inside should be roughened with horizontal saw cuts or lined with a plastic mesh so the bats will have something to grab on to. Do not make the bat box from pressure treated wood, but do use outdoor grade plywood or cedar. A roof will certainly help preserve the bat box, especially if covered with an asphalt shingle or with metal.

It should ideally be mounted on a building where it can more readily absorb heat, or on a pole. Mounting a bat box in a tree will ensure that no bats move in. The bat box should be mounted away from trees and utility wires where bat predators (hawks, owls, etc.) may roost. The bat box should be at least 12 feet from the ground.


text:
Adventist Youth Honors Answer Book/Nature/Bats - Advanced

2. What are caves, attics, bridges, or tunnels where bats hibernate called?
These places where bats sleep during the day or hibernate during the winter are called roosts.

3. Give three (3) examples of colonizing bats.
Other examples of colonizing bats include Rafinesque's big-eared bat (Corynorhinus rafinesquii) and the southeastern myotis (Myotis austroriparius), which are not pictured.

4. Give three (3) examples of solitary roosting bats.
More information can be found at http://www.xpressweb.com/~talon/BatsinAz/furred.html

5. What is meant by delayed implantation?
Delayed implantation is a reproductive strategy used by close to 100 different mammals in seven different orders. In delayed implantation, the embryo does not immediately implant in the uterus, but is maintained in a state of dormancy. No development takes place as long as the embryo remains unattached to the uterine lining. As a result, the normal gestation period is extended, sometimes up to a year.

6. How long is the gestation period for bats?
The gestation period lasts from 44 days to 8 months.

7. What is bat guano and why was it important during the War of 1812 and the Civil War?
Bat guano is bat droppings (feces). Among bat colonies, thousands of pounds of guano can accumulate. During the American War of 1812 and the American Civil War, bat guano was used to make gunpowder, since the primary component of guano is saltpeter – the primary ingredient in gunpowder.

8. What disease can be contracted from large quantities of guano?
Histoplasmosis, also known as Darling's disease, is a disease caused by the fungus Histoplasma capsulatum. Symptoms of this infection vary greatly, but the disease primarily affects the lungs. Occasionally, other organs are affected; this is called disseminated histoplasmosis, and it can be fatal if untreated. Histoplasmosis is common among AIDS patients because of their lowered immune system.

H. capsulatum grows in soil and material contaminated with bird or bat droppings (guano). The fungus has been found in poultry house litter, caves, areas harboring bats, and in bird roosts (particularly those of starlings).

9. What is the life-span of a bat?
Most bats live longer than most mammals of their size. The longest known lifespan of a bat in the wild is 30 years for a little brown bat.

10. Do all bats have rabies?
In regions where rabies is endemic, only 0.5% of bats carry the disease. However, of the few cases of rabies reported in the United States every year not caused by dogs, most are caused by bat bites. Those that are rabid may be clumsy, disoriented, and unable to fly, which makes it more likely that they will come into contact with humans. Although one should not have an unreasonable fear of bats, one should avoid handling them or having them in one's living space, as with any wild animal. If a bat is found in living quarters near a child, mentally handicapped person, intoxicated person, sleeping person, or pet, the person or pet should receive immediate medical attention for rabies. Bats have very small teeth and can bite a sleeping person without being felt.

Where rabies is not endemic, as throughout most of Western Europe, small bats can be considered harmless. Larger bats can give a nasty bite. They should be treated with the respect due to any wild animal.

11. How good is the vision of microbats and megabats?
Although the eyes of most microbat species are small and poorly developed, leading to poor visual acuity, none of them are blind. Vision is used to navigate microbats especially for long distances when beyond the range of echolocation. It has even been discovered that some species are able to detect ultraviolet light. They also have a high quality sense of smell and hearing. Bats hunt at night to avoid competition with birds, and travel large distances at most 800 km, in their search for food.

Most megabats have large eyes, allowing them to orient visually in the twilight of dusk and inside caves and forests. In contrast to the microbats, the fruit bats do not, as a rule, use echolocation (with one exception, the Egyptian fruit bat Rousettus egyptiacus, which uses high-pitched clicks to navigate in caves).

12. What North American bat is pictured on the honor?
The Eastern Red Bat is depicted on the honor patch. They are widespread across eastern North America, with additional records in Bermuda. It is also scarce but widespread throughout many of the Bahamian islands.