text:
Tāmati Wāka Nene

Tāmati Wāka Nene (1780s – 4 August 1871) was a Māori rangatira (chief) of the Ngāpuhi iwi (tribe) who fought as an ally of the British in the Flagstaff War of 1845–46.

Origin and mana
Tāmati Wāka Nene was born to chiefly rank in the Ngāpuhi iwi of the Bay of Islands and Hokianga regions of the North Island of New Zealand. His elder brother was Eruera Maihi Patuone. He was related to Hongi Hika and could trace his ancestry by a number of lines back to Rāhiri, the founder of the Ngāpuhi. He rose to be one of the war leaders of the Ngāpuhi taking an active part in the Musket Wars of 1818–1820. He successfully took his warriors on a rampage the whole length of the North Island, killing and plundering as he went until he reached Cook Strait. It is said that he advised Te Rauparaha to acquire muskets to enhance his influence.

In 1828 he successfully averted a war between the Māori of the Bay of Islands and the Hokianga. Then his older brother moved south to what is now the Auckland region, Hauraki, and soon after the paramount chief of the area died of wounds received in battle. Wāka Nene now became the highest ranking chief among his own people and one of the three primary chiefs of the area. At baptism, he added "Tāmati Wāka" (Thomas Walker) to his name.

Support for the Treaty of Waitangi

Early on he had recognised the value of trade with Pākehā and used his position as chief to protect and encourage both the traders and the Methodist missionaries. He was baptised in 1839 taking the name Thomas Walker or Tāmati Wāka. He also worked with the British Resident, James Busby to regularise the relationships between the two races. In 1835 he signed the Declaration of the Independence of New Zealand which proclaimed the sovereignty of the United Tribes.

At the negotiations leading up to the signing of the Treaty of Waitangi Ngapuhi chief Te Wharerahi disagreed with his brothers Rewa and Moka Te Kainga-mataa and spoke for peace and the acceptance of the European, and was duly supported by Nene and Patuone. Nene's influence was significant in persuading many of the tribes to sign the Treaty.

The next few years saw a considerable loss of revenue and influence for the northern tribes. The capital of the new country was soon moved down to Auckland. Customs duties were also imposed. Then the Government began to manage the land, specifically they temporarily banned any further felling of kauri trees (Agathis australis), after an over-supply of milled kauri occurred in the Australian market.

Commitment to Governor FitzRoy
On 8 July 1844 the flagstaff on Maiki Hill at the north end of Kororāreka was cut down for the first time, by the Pakaraka chief Te Haratua. Heke had set out to cut down the flagstaff but was persuaded by Archdeacon William Williams not to do so.

On 24 August 1844 Governor FitzRoy arrived in the bay from Auckland upon the frigate HMS Hazard (1837). Governor FitzRoy summoned the Ngāpuhi chiefs to a conference at the Te Waimate mission at Waimate on 2 September and apparently defused the situation. Tāmati Wāka Nene requested the Governor to remove the troops and redress the grievances in respect of the Customs duties that were put in place in 1841, that Heke and Pōmare II viewed as damaging the maritime trade from which they benefited. Tāmati Wāka Nene and the other Ngāpuhi chiefs undertook to keep Heke in check and to protect the Europeans in Bay of Islands. Hone Heke did not attend but sent a conciliatory letter and offered to replace the flagstaff.

On 10 January 1845 the flagstaff was cut down a second time, this time by Heke. He again cut down the flagstaff on 19 January. When Hone Heke cut down the flag pole for the fourth time on 11 March 1845 and attacked Kororāreka, Nene was offended, feeling that his mana had been trampled on. Nene was already at war with Heke when the British troops began to arrive on the scene.

Fighting between the warriors of Heke and Nene between Ōkaihau and Te Ahuahu
After the Battle of Kororāreka, Hone Heke and Te Ruki Kawiti and their warriors travelled inland to Lake Ōmāpere near to Kaikohe some 20 mi, or two days travel, from the Bay of Islands. Nene built a pā close to Lake Ōmāpere. Heke's pā named Puketutu, was 2 mi away, while it is sometimes named as "Te Mawhe" however the hill of that name is some distance to the north-east.

In April 1845, during the time that the colonial forces were gathering in the Bay of Islands, the warriors of Heke and Nene fought many skirmishes on the small hill named Taumata-Karamu that was between the two pās and on open country between Ōkaihau and Te Ahuahu. Heke's force numbered about three hundred men; Kawiti joined Heke towards the end of April with another hundred and fifty warriors. Opposing Heke and Kawiti were about four hundred warriors that supported Tāmati Wāka Nene including his brother Eruera Maihi Patuone and the chiefs, Makoare Te Taonui and his brother Aperahama Taonui, Mohi Tawhai, Arama Karaka Pi and Nōpera Panakareao. F. E. Maning, Jacky Marmon and John Webster, of Opononi, Hokianga were three Pākehā Māori (a European turned native) who volunteered to fight with Nene and fought alongside the warriors from Hokianga. Webster used a rifle (a novel weapon at that time) and had made two hundred cartridges.

The colonial forces under the command of Lieutenant Colonel William Hulme, arrived at Heke's Pā at Puketutu on 7 May 1845. Lieutenant Colonel Hulme and his second in command Major Cyprian Bridge made an inspection of Heke's Pā and found it to be quite formidable. Lacking any better plan they decided on a frontal assault the following day. The attack was a failure and the forces retreated to the Bay of Islands. Lieutenant Colonel Hulme returned to Auckland and was replaced by Lieutenant Colonel Henry Despard, a soldier who did very little to inspire any confidence in Wāka Nene.

Nene's defeat of Heke on 12 June 1845 at Pukenui
After the successful defence of Puketutu Pā on the shores of Lake Ōmāpere, Hone Heke returned to his pā at Te Ahuahu. Te Ahuahu was a short distance from both Heke's Pā at Puketutu and the site of the later Battle of Ōhaeawai. Some days later he went on to Kaikohe to gather food supplies. During his absence one of Tāmati Wāka Nene's allies, the Hokianga chief, Makoare Te Taonui (the father of Aperahama Taonui), attacked and captured Te Ahuahu. This was a tremendous blow to Heke's mana or prestige, obviously it had to be recaptured as soon as possible.

The ensuing battle was a traditional formal Māori conflict, taking place in the open with the preliminary challenges and responses. By Māori standards, the battle was considerably large. Heke mustered somewhere between 400 and 500 warriors while Tāmati Wāka Nene had about 300 men. Hone Heke lost at least 30 warriors. Hugh Carleton (1874) provides a brief description of the battle: Heke committed the error (against the advice of Pene Taui) of attacking Walker [Tāmati Wāka Nene], who had advanced to Pukenui. With four hundred men, he attacked about one hundred and fifty of Walker's party, taking them also by surprise; but was beaten back with loss. Kahakaha was killed, Haratua was shot through the lungs

Rev. Richard Davis also recorded that a sharp battle was fought on the 12th inst. between the loyal and disaffected natives. The disaffected, although consisting of 500 men, were kept at bay all day, and ultimately driven off the field by the loyalists, although their force did not exceed 100. Three of our people fell, two on the side of the disaffected, and one on the side of the loyalists. When the bodies were brought home, as one of them was a principal chief of great note and bravery, he was laid in state, about a hundred yards from our fence, before he was buried. The troops were in the Bay at the time, and were sent for by Walker, the conquering chief; but they were so tardy in their movements that they did not arrive at the seat of war to commence operations until the 24th inst.!

Wāka Nene remained in control of Heke's pā. Heke was severely wounded and did not rejoin the conflict until some months later, at the closing phase of the Battle of Ruapekapeka. In a letter to Lieutenant Colonel Despard the battle was described by Wāka Nene as a "most complete victory over Heke".

Battle of Ōhaeawai

Tāmati Wāka Nene and his warriors supported troops led by Lieutenant Colonel Despard in an attack on Pene Taui's pā at Ōhaeawai. Kawiti and Pene Taui had strengthened the defences of the pā.

Nene and Despard fought side by side as allies although Despard had an almost complete incomprehension about Nene's experience in attacking fortified pās. At Ōhaeawai, Nene offered to make a feint attack on the rear of the pā, to divert attention from the soldiers' assault, but this suggestion, like all others offered by Nene, met with a refusal. Nene described the British commander, Lieutenant Colonel Despard, as 'a very stupid man'. Despard on the other hand said "if I want help from savages I will ask for it". History tends to support Nene's opinion as he had achieved a decisive win against Hone Heke on 12 June 1845, with no help from the British.

At the Battle of Ōhaeawai after two days of bombardment without effecting a breach, Despard ordered a frontal assault. He was, with difficulty, persuaded to postpone this pending the arrival of a 32-pound naval gun which came the next day, 1 July. However an unexpected sortie from the pā resulted in the temporary occupation of the knoll on which Tāmati Wāka Nene had his camp and the capture of Nene's colours – the Union Jack. The Union Jack was carried into the pā. There it was hoisted, upside down, and at half-mast high, below the Māori flag, which was a Kākahu (Māori cloak).

This insulting display of the Union Jack was the cause of the disaster which ensued. Infuriated by the insult to the Union Jack Colonel Despard ordered an assault upon the pā the same day. The attack was directed to the section of the pā where the angle of the palisade allowed a double flank from which the defenders of the pā could fire at the attackers; the attack was a reckless endeavour. The British persisted in their attempts to storm the unbreached palisades and five to seven minutes later 33 were dead and 66 injured, approximately one-third of the soldiers and Royal Marines.

Battle of Ruapekapeka

Tāmati Wāka Nene and his warriors supported troops led by Lieutenant Colonel Despard in an attack on the pā at Ruapekapeka. Kawiti's tactics was to attempt to repeat the success of the Battle of Ōhaeawai and draw the colonial forces into an attack on heavily fortified pā. The colonial forces started a cannon bombardment of Ruapekapeka Pā on 27 December 1845. The siege continued for some two weeks with enough patrols and probes from the pā to keep everyone alert. Then, early in the morning of Sunday, 11 January 1846,Tāmati Wāka Nene's men discovered that the pā appeared to have been abandoned; although Te Ruki Kawiti and a few of his warriors remained behind, and appeared to have been caught unaware by the British assault. The assaulting force drove Kawiti and his warriors out of the pā. Fighting took place behind the pā and most casualties occurred in this phase of the battle.

After the Battle of Ruapekapeka, Heke and Kawiti were ready for peace. They approached Wāka Nene to act as the intermediary to negotiate with Governor Grey. Nene insisted that no action should be taken against Heke and Kawiti for leading the war.

Mana of Wāka Nene after the Northern War
The Government lost a great deal of mana and influence in the North as a result of the war, much of which flowed to Tāmati Wāka Nene. He and Heke were recognised as the two most influential men in the North. He was given a pension of one hundred pounds a year and had a cottage built for him in Kororareka (Russell). He continued to advise and assist the Government on matters such as the release of Pomare II in 1846 and Te Rauparaha in 1848.

When George Grey was knighted he chose Nene as one of his esquires. Then when he returned for his second term of governorship in 1860 he brought Nene a silver cup from Queen Victoria. Nene accompanied Grey to Taranaki to negotiate a truce with Wiremu Tamihana (the King maker) to end the First Taranaki War in 1861. En route to New Plymouth the ship struck a huge storm but survived which was taken as a favourable omen.

Death

Tāmati Wāka Nene died on 4 August 1871, and is buried in Russell. The Governor at the time, Sir George Bowen, said that Nene did more than any other Māori to promote colonisation and to establish the Queen's authority.

title: Tāmati Wāka Nene


text:
Talk:Ode to Freedom

Untitled
This should be merged with Hymn to Freedom -- the Greek and Cypriot national anthems are in fact the same song (unsurprising, since it was the initial intent of the two countries to merge). --Delirium 09:01 18 Jul 2003 (UTC)

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

title: Talk:Ode to Freedom


text:
Fresnel integral

The Fresnel integrals $S(x)$ and $C(x)$ are two transcendental functions named after Augustin-Jean Fresnel that are used in optics and are closely related to the error function ($C(x)$). They arise in the description of near-field Fresnel diffraction phenomena and are defined through the following integral representations:

$$S(x) = \int_0^x \sin\left(t^2\right)\,dt, \quad C(x) = \int_0^x \cos\left(t^2\right)\,dt.$$

The parametric curve $0.977$ is the Euler spiral or clothoid, a curve whose curvature varies linearly with arclength.

Definition
The Fresnel integrals admit the following power series expansions that converge for all $S$: $$\begin{align} S(x) &= \int_0^x \sin\left(t^2\right)\,dt = \sum_{n=0}^{\infin}(-1)^n \frac{x^{4n+3}}{(2n+1)!(4n+3)}, \\ C(x) &= \int_0^x \cos\left(t^2\right)\,dt = \sum_{n=0}^{\infin}(-1)^n \frac{x^{4n+1}}{(2n)!(4n+1)}. \end{align}$$

Some widely used tables use $π⁄2t^{2}$ instead of $t^{2}$ for the argument of the integrals defining $S(x)$ and $C(x)$. This changes their limits at infinity from $erf$ to $C$ and the arc length for the first spiral turn from $π⁄2t^{2}$ to 2 (at $t^{2}$). These alternative functions are usually known as normalized Fresnel integrals.

Euler spiral
The Euler spiral, also known as a Cornu spiral or clothoid, is the curve generated by a parametric plot of $1⁄2·√π/2$ against $π⁄2t^{2}$. The Euler spiral was first studied in the mid 18th century by Leonhard Euler in the context of Euler–Bernoulli beam theory. A century later, Marie Alfred Cornu constructed the same spiral as a nomogram for diffraction computations.

From the definitions of Fresnel integrals, the infinitesimals $\bigl(S(t), C(t)\bigr)$ and $1⁄2$ are thus: $$\begin{align} dx &= C'(t)\,dt = \cos\left(t^2\right)\,dt, \\ dy &= S'(t)\,dt = \sin\left(t^2\right)\,dt. \end{align}$$

Thus the length of the spiral measured from the origin can be expressed as $$L = \int_0^{t_0} \sqrt {dx^2 + dy^2} = \int_0^{t_0} dt = t_0. $$

That is, the parameter $x$ is the curve length measured from the origin $t^{2}$, and the Euler spiral has infinite length. The vector $S(x)$ also expresses the unit tangent vector along the spiral, giving $C(x)$. Since $1⁄2$ is the curve length, the curvature $t$ can be expressed as $$ \kappa = \frac{1}{R} = \frac{d\theta}{dt} = 2t. $$

Thus the rate of change of curvature with respect to the curve length is $$\frac{d\kappa}{dt} = \frac {d^2\theta}{dt^2} = 2. $$

An Euler spiral has the property that its curvature at any point is proportional to the distance along the spiral, measured from the origin. This property makes it useful as a transition curve in highway and railway engineering: if a vehicle follows the spiral at unit speed, the parameter $dx$ in the above derivatives also represents the time. Consequently, a vehicle following the spiral at constant speed will have a constant rate of angular acceleration.

Sections from Euler spirals are commonly incorporated into the shape of rollercoaster loops to make what are known as clothoid loops.

Properties
$1⁄2·√π⁄2$ and $√2π$ are odd functions of $dy$,

$$C(-x) = -C(x), \quad S(-x) = -S(x).$$

which can be readily seen from the fact that their power series expansions have only odd-degree terms, or alternatively because they are antiderivatives of even functions that also are zero at the origin.

Asymptotics of the Fresnel integrals as $t = 2$ are given by the formulas:

$$\begin{align} S(x) & =\sqrt{\tfrac18\pi} \sgn x - \left[ 1 + O\left(x^{-4}\right) \right] \left( \frac{\cos\left(x^2\right)}{2x} + \frac{\sin\left(x^2\right)}{ 4x^3 } \right), \\[6px] C(x) & =\sqrt{\tfrac18\pi} \sgn x + \left[ 1 + O\left(x^{-4}\right) \right] \left( \frac{\sin\left(x^2\right)}{2x} - \frac{\cos\left(x^2\right)}{ 4x^3 } \right). \end{align}$$

Using the power series expansions above, the Fresnel integrals can be extended to the domain of complex numbers, where they become entire functions of the complex variable $t$.

The Fresnel integrals can be expressed using the error function as follows:

$$\begin{align} S(z) & =\sqrt{\frac{\pi}{2}} \cdot\frac{1+i}{4} \left[ \operatorname{erf}\left(\frac{1+i}{\sqrt{2}}z\right) -i \operatorname{erf}\left(\frac{1-i}{\sqrt{2}}z\right) \right], \\[6px] C(z) & =\sqrt{\frac{\pi}{2}} \cdot\frac{1-i}{4} \left[ \operatorname{erf}\left(\frac{1+i}{\sqrt{2}}z\right) + i \operatorname{erf}\left(\frac{1-i}{\sqrt{2}}z\right) \right]. \end{align}$$

or

$$\begin{align} C(z) + i S(z) & = \sqrt{\frac{\pi}{2}}\cdot\frac{1+i}{2} \operatorname{erf}\left(\frac{1-i}{\sqrt{2}}z\right), \\[6px] S(z) + i C(z) & = \sqrt{\frac{\pi}{2}}\cdot\frac{1+i}{2} \operatorname{erf}\left(\frac{1+i}{\sqrt{2}}z\right). \end{align}$$

Limits as $(x, y) = (C(t), S(t))$ approaches infinity
The integrals defining $S(t)$ and $C(t)$ cannot be evaluated in the closed form in terms of elementary functions, except in special cases. The limits of these functions as $t$ goes to infinity are known: $$\int_0^\infty \cos \left(t^2\right)\,dt = \int_0^\infty \sin \left(t^2\right) \, dt = \frac{\sqrt{2\pi}}{4} = \sqrt{\frac{\pi}{8}} \approx 0.6267.$$

This can be derived with any one of several methods. One of them uses a contour integral of the function $$ e^{-z^2}$$ around the boundary of the sector-shaped region in the complex plane formed by the positive $(0, 0)$-axis, the bisector of the first quadrant $(cos(t^{2}), sin(t^{2}))$ with $θ = t^{2}$, and a circular arc of radius $C(x)$ centered at the origin.

As $S(x)$ goes to infinity, the integral along the circular arc $x → ∞$ tends to $S(z)$ $$\left|\int_{\gamma_2}e^{-z^2}\,dz\right| = \left|\int_0^\frac{\pi}{4}e^{-R^2(\cos t + i \sin t)^2}\,Re^{it}dt\right| \leq R\int_0^\frac{\pi}{4}e^{-R^2\cos2t}\,dt \leq R\int_0^\frac{\pi}{4}e^{-R^2\left(1-\frac{4}{\pi}t\right)}\,dt = \frac{\pi}{4R}\left(1-e^{-R^2}\right),$$ where polar coordinates $√π/2$ were used and Jordan's inequality was utilised for the second inequality. The integral along the real axis $C(z)$ tends to the half Gaussian integral $$\int_{\gamma_1} e^{-z^2} \, dz = \int_0^\infty e^{-t^2} \, dt = \frac{\sqrt{\pi}}{2}.$$

Note too that because the integrand is an entire function on the complex plane, its integral along the whole contour is zero. Overall, we must have $$\int_{\gamma_3} e^{-z^2} \, dz = \int_{\gamma_1} e^{-z^2} \, dz = \int_0^\infty e^{-t^2} \, dt,$$ where $x$ denotes the bisector of the first quadrant, as in the diagram. To evaluate the left hand side, parametrize the bisector as $$z = te^{i\frac{\pi}{4}} = \frac{\sqrt{2}}{2}(1 + i)t$$ where $κ$ ranges from 0 to $C(x)$. Note that the square of this expression is just $S(x)$. Therefore, substitution gives the left hand side as $$\int_0^\infty e^{-it^2}\frac{\sqrt{2}}{2}(1 + i) \, dt.$$

Using Euler's formula to take real and imaginary parts of $x$ gives this as $$\begin{align} & \int_0^\infty \left(\cos\left(t^2\right) - i\sin\left(t^2\right)\right)\frac{\sqrt{2}}{2}(1 + i) \, dt \\[6px] &\quad = \frac{\sqrt{2}}{2} \int_0^\infty \left[\cos\left(t^2\right) + \sin\left(t^2\right) + i \left(\cos\left(t^2\right) - \sin\left(t^2\right)\right) \right] \, dt \\[6px] &\quad = \frac{\sqrt{\pi}}{2} + 0i, \end{align}$$ where we have written $y = x$ to emphasize that the original Gaussian integral's value is completely real with zero imaginary part. Letting $$I_C = \int_0^\infty \cos\left(t^2\right) \, dt, \quad I_S = \int_0^\infty \sin\left(t^2\right) \, dt$$ and then equating real and imaginary parts produces the following system of two equations in the two unknowns $x ≥ 0$ and $R$: $$\begin{align} I_C + I_S & = \sqrt{\frac{\pi}{2}}, \\ I_C - I_S & = 0. \end{align}$$

Solving this for $R$ and $γ_{2}$ gives the desired result.

Generalization
The integral $$\int x^m e^{ix^n}\,dx = \int\sum_{l=0}^\infty\frac{i^lx^{m+nl}}{l!}\,dx = \sum_{l=0}^\infty \frac{i^l}{(m+nl+1)}\frac{x^{m+nl+1}}{l!}$$ is a confluent hypergeometric function and also an incomplete gamma function $$\begin{align} \int x^m e^{ix^n}\,dx & =\frac{x^{m+1}}{m+1}\,_1F_1\left(\begin{array}{c} \frac{m+1}{n}\\1+\frac{m+1}{n}\end{array}\mid ix^n\right) \\[6px] & =\frac{1}{n} i^\frac{m+1}{n}\gamma\left(\frac{m+1}{n},-ix^n\right), \end{align}$$ which reduces to Fresnel integrals if real or imaginary parts are taken: $$\int x^m\sin(x^n)\,dx = \frac{x^{m+n+1}}{m+n+1} \,_1F_2\left(\begin{array}{c}\frac{1}{2}+\frac{m+1}{2n}\\ \frac{3}{2}+\frac{m+1}{2n},\frac{3}{2}\end{array}\mid -\frac{x^{2n}}{4}\right).$$ The leading term in the asymptotic expansion is $$ _1F_1 \left(\begin{array}{c}\frac{m+1}{n}\\1+\frac{m+1}{n} \end{array}\mid ix^n\right)\sim \frac{m+1}{n}\,\Gamma\left(\frac{m+1}{n}\right) e^{i\pi\frac{m+1}{2n}} x^{-m-1},$$ and therefore $$\int_0^\infty x^m e^{ix^n}\,dx = \frac{1}{n} \,\Gamma\left(\frac{m+1}{n}\right)e^{i\pi\frac{m+1}{2n}}.$$

For $0$, the imaginary part of this equation in particular is $$\int_0^\infty\sin\left(x^a\right)\,dx = \Gamma\left(1+\frac{1}{a} \right) \sin\left(\frac{\pi}{2a}\right),$$ with the left-hand side converging for $z = Re^{it}$ and the right-hand side being its analytical extension to the whole plane less where lie the poles of $γ_{1}$.

The Kummer transformation of the confluent hypergeometric function is $$ \int x^m e^{ix^n}\,dx = V_{n,m}(x)e^{ix^n},$$ with $$V_{n,m} := \frac{x^{m+1}}{m+1}\,_1F_1\left(\begin{array}{c} 1 \\ 1 + \frac{m+1}{n} \end{array}\mid -ix^n\right).$$

Numerical approximation
For computation to arbitrary precision, the power series is suitable for small argument. For large argument, asymptotic expansions converge faster. Continued fraction methods may also be used.

For computation to particular target precision, other approximations have been developed. Cody developed a set of efficient approximations based on rational functions that give relative errors down to $t$. A FORTRAN implementation of the Cody approximation that includes the values of the coefficients needed for implementation in other languages was published by van Snyder. Boersma developed an approximation with error less than $x$.

Applications
The Fresnel integrals were originally used in the calculation of the electromagnetic field intensity in an environment where light bends around opaque objects. More recently, they have been used in the design of highways and railways, specifically their curvature transition zones, see track transition curve. Other applications are rollercoasters or calculating the transitions on a velodrome track to allow rapid entry to the bends and gradual exit.

title: Fresnel integral


text:
Talk:Montecristo

Disambiguation
I wold like to propose some sort of disambiguation for this page, since a link from another page discussing Cuban cigars comes to this page. Any takers?

 * If the wikilink in Cohiba (cigar brand) is linking here instead of Montecristo (cigar brand), you can correct it by "piping" the link to look like this: Montecristo . That makes the article text show the word Montecristo, but clicking the link will go to the article about the cigar brand instead of the island. There's already a link to the disambiguation page at the top of this article, so that should be sufficient. Hope that helps. :-) --NormanEinstein 01:55, 24 April 2006 (UTC)

Photo
i disagree with the line under the photo of montecristo, because the island is 80km offcoast and being only 4km wide it would inpossible to see it that big unless you maginify your vision.--82.61.21.76 20:26, 12 March 2007 (UTC) p.kowalski@alice.it

Monte Cristo opens up to tourists
According to an article dated 24th March,2008 published by ANI (Asian News International), Monte Cristo will soon be open to the general public for the first time in many decades.

Here's the link to the article - http://news.webindia123.com/news/Articles/World/20080324/916043.html

The current version of the Wikipedia article states that "The island is remote and kept by the Italian government as a nature preserve and hunting park, and only accessible by private yacht and permit."

As this is my first post as a Wikipedia member I'm unfamiliar with the whole editing process, so someone who's well versed with it please do make the necessary changes after perusing the above mentioned article.

--Azeb (talk) 07:35, 25 March 2008 (UTC)

 * My dear, 4 years is a lot of time, especially in Italy. ;-) This was one of the crazy ideas of the previous government, which followed always the same pattern: first launch a mad idea, like opening to tourism an integral nature preserve, then watch the reaction of the public opinion, at the end forget the whole thing. Don't worry, Monte Cristo is still inaccessible and hopefully will so remain also in the future. Bye, Alex2006 (talk) 06:11, 7 March 2012 (UTC)

Death to Rats
Like a lot of people, Wiki seems to dramatize the attempt to reduce murine population of Montecristo Island. "poison" and "bombing" terms remind me a sad chemical war chronicle. It is simply pellet bait with rodenticide wisely diffused over island's climbs and valleys, and not a devastating pollution episode or a wildlife menace.

 * I expanded the article and proposed it for DYK, and I totally agree with you. I removed twice the story of the rats, only to discover that someone else put it again. At the end I gave up. By the way, what it is written on the media is largely exaggerated or plainly false. The only serious reference is the pdf which i added. Unfortunately, a lot of people thinks that Wikipedia is a gossip site, and fighting against them is like emptying the ocean with a spoon... Bye, Alex2006 (talk) 06:08, 7 March 2012 (UTC)

 * I'm not so sure... this 'serious reference' (by involved persons) says Il ratto nero Rattus rattus è presente a Montecristo presumibilmente dall’epoca Romana and I think 'presumibilmente' is interesting - although you cited this is as a fact in your edit summary - but not so much as Un’aumentata incidenza della predazione da parte dei ratti, indotta da un loro probabile aumento numerico conseguente all’incremento numerico della popolazione nidificante di gabbiano reale Larus michahellis avvenuto a partire dagli anni ’70 del XX secolo. It's not beyond the bounds of possibility that there might be un loro probabile aumento numerico conseguente all’incremento numerico della popolazione nidificante dei umani. Particularly as there are recent sources for the opening of the island to tourism and the Minister of the Environment herself suggested that the island could be "Sold for Tourism", a source you removed, Maculosae tegmine lyncis (talk) 17:08, 10 March 2012 (UTC)

 * These persons are "involved" in this story as much as Einstein was involved in Relativity. They are scientists which studied the problem and looked for a solution (if you understand Italian, you can find their names in the document). Personally, as source for an encyclopedia article I prefer always a scientific paper to (more or less serious) newspaper articles, which starts always from the paper. About the rats, you can read what is written on the paper about the diffusion of the rats in the Mediterranean islands. About the removal of the other story, I already explained you the reason: it is not actual anymore, it was just one of thousand ballon d'essai of the previous government. If you can find an actual and reliable source (Ministero dell'ambiente, Parco nazionale) which announces the future opening of the island, we can put it back on the article. But writing every gossip (also invented by the journalist, as the story that the rats arrived in the last years by boat) in not encyclopedic, and - above all - not serious. Bye, Alex2006 (talk) 18:06, 10 March 2012 (UTC)

External links modified (February 2018)
Hello fellow Wikipedians,

I have just modified 3 external links on Montecristo. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
 * Corrected formatting/usage for http://www.uniurb.it/giornalismo/lavori2004/esposito/timeline.htm
 * Corrected formatting/usage for http://www.uniurb.it/giornalismo/lavori2004/esposito/Benelli/Benelli.html
 * Added archive https://web.archive.org/web/20110702235936/http://minambiente.it/home_it/menu.html?mp=%2Fmenu%2Fmenu_attivita%2F&m=argomenti.html to http://www.minambiente.it/home_it/menu.html?mp=%2Fmenu%2Fmenu_attivita%2F&m=argomenti.html

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

Cheers.— InternetArchiveBot  (Report bug) 00:40, 5 February 2018 (UTC)

title: Talk:Montecristo


text:
Talk:Hydrogenation

Hydrogenes
Why is there no mention of Hydrogenes, the ancient greek scientist who first discovered the phenomenon? --Dante Alighieri 09:37 18 Jul 2003 (UTC)
 * Because noone has written it yet? Why don't you :) Mat-C 12:52, 29 Apr 2004 (UTC)

Margaret Thatcher as a chemist
Rumour has it that Margaret Thatcher (the English Prime Minister) invented/developed hydrogenated fats in her previous career as a chemist, does anyone have any hard facts on this? Mat-C 12:52, 29 Apr 2004 (UTC)

 * Well, the first patent on the process as we know it was by the German chemist Wilhelm Normann in 1902, so we know she did not start it. There have been improvements over the years though. I saw some patents mentioned as late as 1959. From the web I see that she worked as a research chemist for about 4 years, 47-51, and one thing she worked on was a process for mixing air into ice cream. It seems unlikely that she made any major contributions to hydrogenation. AJim 04:10, 30 Apr 2004 (UTC)

 * Yes, it was air into ice-cream. -- The Anome 07:17, 30 Apr 2004 (UTC)

 * omg don't even tell me she invented hydrogenation. if that was the case i would believe that the devil exists and that thatcher is the incarnation of satan. —The preceding unsigned comment was added by 72.139.207.240 (talk • contribs).

chinese version link
the link to the chinese language version directs to http://zh.wikipedia.org/wiki/%E8%84%B1%E6%B0%A2, which is for 脱氢, DEhydrogenation.

shouldn't it be directed to hydrogenation, http://zh.wikipedia.org/wiki/%E6%B0%A2%E5%8C%96, ie, 氢化? —Preceding unsigned comment added by 24.63.106.230 (talk • contribs) June 25, 2006 (UTC) gorganites and gimli —Preceding unsigned comment added by 88.105.236.193 (talk) 20:01, 3 May 2010 (UTC)
 * Depending on where equilibrium is, it is the same process. It is reversible. Gah4 (talk) 21:41, 22 July 2021 (UTC)
 * Depending on where equilibrium is, it is the same process. It is reversible. Gah4 (talk) 21:41, 22 July 2021 (UTC)

partially hydrogenated
isn't this very bad for the human body?? why don't some one school me in this. i was told that this causes trans fats in food products, is this correct? i was also told that this hydrogenated oil covers the cells,(the fatty acids job), coats it and does not let the good things(vitamins, nutrients)come in the cell and pretty much tells the fatty acids to take a hike, so the fatty acids then go toward the skin like your face, hips, stomach, thighs and anywhere else people tend to gain weight at. the man made hydrogenated oils do not let the good things come in the cell, but yet allow the bad things to come in. thus we have diabetes, heart disease, obesity and all sorts of health issues, all because we want a longer shelf life on a food product, all because we can make more money, that is why people are going so health nutty and buying all organic food, cuz it has fatty acids, like omega 3, which are very good and natural which the body can use and break down. i heard the human body does can not even use or break down this hydrogenated oil. ??? can some one clear this up??? —The preceding unsigned comment was added by 163.181.251.10 (talk • contribs).

 * Hydrogenation does produce trans fatty acids, as the article says in the "Health implications" section.

The American Heart website says that full hydrogenation does not produce trans fatty acids, and I think that information should be included in the article. 65.222.231.2 (talk) 14:09, 24 June 2008 (UTC)

 * Consensus is that trans fatty acids are indeed bad for you. See Trans fat.
 * I don't think your explanation of the process by which they do harm is correct (but then again, who knows?). Also, you seem to separate everything into neat categories of "good things" and "bad things", when the truth is that too much of anything is bad for you. Example: potassium is an essential mineral, but it's also the main component of lethal injections. —Keenan Pepper 23:13, 8 September 2006 (UTC)

The "Health implications" section of this article is completely incomplete. Every single statement in that short paragraph relate to trans fats. The implication is that partial hydrogenation by definition produces primarily trans facts. This is incorrect. Refer to the "Further reading" section of this article: Jang ES, Jung MY, Min DB (2005). "Hydrogenation for Low Trans and High Conjugated Fatty Acids". That article discusses a process proving my point. Therefore and in summary, this paragraph should be moved to Trans fat in its current state, and new content written addressing the health implications of hydrogenated oils with AND without trans fats. Leafgreen (talk) 19:22, 26 September 2009 (UTC)

Let's put this in context. I have in front of me 17 different packages of foods by manufacturers such as Kraft, Nestle, McKee and IBC. Each have in the list of ingredients "partially hydrogenated...oil" as the ONLY fat/oil. On every one of the the Nutrition Facts panels, no trans fat is listed. Therefore, these manufacturers are using a type of partially hydrogenated oil that has less than 0.5 grams of trans fat. Is this formulation of partially hydrogenated oil cardiopathic? Leafgreen (talk) 19:22, 26 September 2009 (UTC)

But how much of that partially hydrogenated stuff is in a serving? I'm looking at a package of cookies that have a serving size of 31 g. The total fat content is only 2g per serving. If something actually had 0.5 g of trans fat (these cookies are listed as having 0 g of trans fat), that would be 25% of the total fat. At these quantities, the numbers are often very misleading. For instance, as I mentioned earlier, these cookies have 2 g of fat (total) per serving. Further reading shows that this is made up of 0 g saturated fat, 0 g of monounsaturated fat and 1 g of polyunsaturated fat. This doesn't add up. Those three numbers are all possible types of fat there are (trans fat being a type of unsaturated fat), but half of the fat is missing. What really needs to happen is that the government needs to make packaging information more reasonable, so that you don't get people thinking that 0 + 0 + 1 = 2. —Preceding unsigned comment added by 67.116.29.174 (talk) 00:33, 28 February 2011 (UTC)

Hydrogenation vs. Protonation
What is the difference between hydrogenation and protonation? Is it simply that hydrogenation is the addition of H2 while protonation is the additon of H+? This should be addressed in the article. --Ttownfeen 00:43, 28 February 2007 (UTC)

 * The answer to your own question is correct and yes this bit of information must be included in the article, consider it done V8rik 22:15, 28 February 2007 (UTC)

Butter
I understand that the process for making butter from cream is very different than that for hydrogenating vegetable oils into margarine, but is there any chemical similarity in the result? Can one say that butter is "naturally hydrogenated" to some extent, or is it instead the case that butter's solidity at room temperature is different than margarine's?

(Trying to partially deflate an email that makes out margarine to be the devil. I say it's only a minor demon.) 69.248.200.36 17:26, 19 August 2007 (UTC)
 * Hydrogenation is the chemical process of adding H atoms to stuff, converting unsaturated molecules into molecules that are more saturated. Making butter from cream is a physical process that congeals the fat globules (the whiteness of milk or cream) without changing the degree of saturation of these fats. Butterfat in these globules is 65% saturated. Margerine has a lower percentage of saturated fat than does butter.--Smokefoot 00:17, 21 August 2007 (UTC)

measuring gas used
Anyone know (or better also have a picture) of the apparatus used to measure the amount of H2 taken up in the reaction? I recall using an apparatus which appeared to be a burette with a pipe connected to a separating funnel full of a coloured liquid and sort of lining up the levels of a liquids in the funnel and the burette and measuring the volume removed (something to do with pressure equalization ... bit of a sketchy description I know! -- Quantockgoblin (talk) 16:55, 28 April 2008 (UTC)

Hydrogenated protein?
What is the purpose of hydrogenating protein? I bought some peanuts that have "hydrogenated soy protein" listed as an ingredient. What is the purpose of this?--Hraefen Talk 18:50, 23 June 2008 (UTC)

 * There are so few results after searching for "hydrogenated soy protein" in Google Books, Google Scholar, and even Google, that I wonder if this is not a mistake. On the other hand, there are lots of results if you search for "hydrogenated soy oil", which makes sense. --Itub (talk) 08:05, 26 June 2008 (UTC)

 * Thanks for responding. This guy here thinks that "hydrogenated protein" is just another way to say hydrolyzed vegetable protein, which is just a free glutamate, so basically, MSG.--Hraefen Talk 21:42, 26 June 2008 (UTC)

Use of non-SI units
If possible, it would be nice to get the diagrams on the page to follow a standard format i.e. converting pressures from Pounds per square inch to bar. Does anyone have the source diagrams to alter them? --Dumas 1830 (talk) 16:39, 7 August 2008 (UTC)

 * You'd have to contact the people who created the diagrams (or redraw them from scratch). --Itub (talk) 16:50, 7 August 2008 (UTC)
 * I am thinking about replacing the figs and omitting units and many details, which would be difficult to understand to the non-specialist and not needed by the specialist. Suggestions are welcome. Compare
 * [[Image:MaleicH2n.png|420px]]

with
 * [[Image:MaleicAcidHydrogenation.svg]]
 * I need suggestions for finding the chem equations related to trans fats, which is what people are probably seeking here.--Smokefoot (talk) 17:36, 7 August 2008 (UTC)

 * The trans fat article has nice figures of oleic acid and its hydrogenation and isomerization (i.e., trans) products, but it doesn't say much about the reaction itself or the catalyst used.
 * I understand the motivation for removing unnecessary detail from the equations, but perhaps it would be useful to keep a distinction between the hydrogenation reactions that occur at normal pressures and those that require high pressure? There are significant practical differences between hydrogenating something at 1 atm vs doing it at 100 atm! --Itub (talk) 12:05, 8 August 2008 (UTC)

 * New tests. Here are the suggested replacements for the hydrogenation reactions in hydrogenation. Comments welcome.  I was thinking that there may be too many equations in the current page so I selected some.  Questions, did I select good ones, is the layout and content okay?

--Smokefoot (talk) 13:20, 8 August 2008 (UTC)

 * Great stuff... If only I could create (easily) chemical diagrams, then I could change the psi to atm or bar without having to ask you people (thanks though!).

Smokefoot, looks like a good selection. --Dumas 1830 (talk) 18:47, 8 August 2008 (UTC)

There are free chemical drawing programs out there. Here's a review of several free and commercial programs. http://www.cic.klte.hu/~gundat/rajzprogramok/dprog.html Dikbrown (talk) 00:47, 28 February 2011 (UTC)

Is it possible to hydrogenate solids (like nuts, whole chuncks of pork fat, suet)?
Can solids ever by hydrogenated? Like, could you ever find whole nuts that have been hydrogenated? How can you tell if pig fat (unrendered lard) that you buy in whole chucks at the meat section in the supermarket is hydrogenated? —Preceding unsigned comment added by Jacktherrr (talk • contribs) 13:58, 22 January 2009 (UTC)
 * No, this only works in solution. Cacycle (talk) 14:57, 22 January 2009 (UTC)

 * No, it's not possible, because the alkene bond must adsorb on the catalyst surface for the reaction to occur. This is possible only for fluids. Hydrogenation without a catalyst does not occur at reasonable temperatures. As for pig fat, there's no reason to hydrogenate it. Partial hydrogenation is/was used for converting cheaper plant oil (liquid unsaturates) into a more solid saturate/trans-unsaturate mixture to replace the more expensive saturated fats from animal sources, like butter or lard. When you already have expensive solid fat from an animal source, like lard, there's no point in hydrogenating it. --Vuo (talk) 00:07, 23 January 2009 (UTC)
 * Lard and butter is usually hydrogenated to extend shelf life and improve texture, hence they also can't be trusted not to contain artificial trans fat anymore. (Just search for hydrogenated lard) Ma770 (talk) 10:57, 6 May 2010 (UTC)

Electrolytic Hydrogenation
Electrolytic hydrogenation is commonly done in lab settings. It gets very high yields when converting ketones to 2ndary alcohols, aldehydes to primary alcohols, and alkenes to alkanes. It just uses an iron cathode which also acts as a catalyst and a sacrificial nickel anode. You can view the source here: http://pubs.acs.org/doi/pdf/10.1021/ed081p1350 I'm not sure if it warrants a spot in this article as it may be too specific of a process. Kasooi (talk) 02:05, 19 August 2011 (UTC)

The image of the hydrogenation reaction
I just thought I would mention this tiny mistake, sorry for the pedantry: A triacylglycerol containing two linoleate residues and one oleate residue is shown as being partially hydrogenated to a triacylglycerol containing two oleate residues and one stearate residue. However, the picture incorrectly shows a palmitate residue in place of the stearate. I don't know how to edit images, sorry. — Preceding unsigned comment added by 205.250.1.132 (talk) 03:57, 21 June 2014 (UTC)

Redirections
I had commented that hydrogenated vegetable oil should point here, rather than to trans fat because I thought it was misleading. On further thought, it should really point to saturated fat. I would guess most people put these terms in from ingredient labels, and they would be best served by being taken to something relevant to their questions. I believe on US labels, simply saying "hydrogenated" means hydrogenated to saturation. — Preceding unsigned comment added by 71.127.245.95 (talk) 12:51, 2 October 2017 (UTC)

External links modified
Hello fellow Wikipedians,

I have just modified one external link on Hydrogenation. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
 * Added archive https://web.archive.org/web/20081217185908/http://members.ift.org/NR/rdonlyres/27B49B9B-EA63-4D73-BAB4-42FEFCD72C68/0/crfsfsv4n1p00220030ms20040577.pdf to http://members.ift.org/NR/rdonlyres/27B49B9B-EA63-4D73-BAB4-42FEFCD72C68/0/crfsfsv4n1p00220030ms20040577.pdf

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

Cheers.— InternetArchiveBot  (Report bug) 10:23, 9 November 2017 (UTC)

Corrections made in Table entitled "Substrates for and products of hydrogenation" in same topic (1.3.)
-1) header of last column : there must be enthalpy of hydrogenation rather than "heat of hydrogenation", since negative values are given, and the fact that C-C double bond hydrogenation is exothermal (as otherwise mentioned in the text) and the well known relation QR(heat of reaction) = - delHR(enthalpy of reaction) ; -2) values in the last column are much too small (or, in other words, much too high in absolute value) or the unit, kcal/mol, is wrong ! If the unit is changed to kJ/mol, the values ranges given in this last column become acceptable. In conclusion I've changed the unit from kcal/mole to kJ/mole and delete all the minus signs (or replace the 4th column header with Enthalpy of hydrogenation), in order to correct the table.

Refs: 1. F. A. Carey, Organic chemistry, McGraw-Hill, 2004, 5ed., p. 233, Table 6.1., where (correctly named) positive values given for "Heat of hydrogenation" are ranging between 136 kJ/mole (32.6 kcal/mole) for ethylene and 110 kJ/mole (26.4 kcal/mole) for 2,3-dimethyl-2-butene.

2. In Tables 10.36 (p.374), 10.37 (p.379) of ref. [4] (Barnicki in Kent Handbook, 12th ed.) quoted for the header of 4th column, the correct unit, kJ/mole, is specified. Unfortunately, in the original reference [4] same misleading naming is used, i.e. "Heat of reaction" instead of Enthalpy of reaction, in Table 10.36 for the (negative) values given for hydrogenation of various functional groups and in Table 10.37 for (positive) values listed for dehydrogenation reactions.

Regards, Liv.Ichimescu (talk) 17:36, 18 February 2018 (UTC)
 * I agree there were lots of inconsistencies. The cited ref has negative values (and one was also not transcribed correctly) in units of "kJ/gmole", so your kJ/mol is clearly a correct correction. The cited ref notes that the reaction is "highly exothermic" and in previous and subsequent pages appears to use "ΔHrxn" for this idea. Our heat of reaction points to the ΔH sense also, and specifically identifies "Standard enthalpy of hydrogenation" as a known phrase. DMacks (talk) 21:11, 18 February 2018 (UTC)
 * Might have been my fault, but in any case it is great that Ichimescu improved the table! It would be good to have an entry for aromatics, showing the the enthalpy is not three times that of isolated alkenes.--Smokefoot (talk) 21:36, 18 February 2018 (UTC)

Theory of semihydrogenated state (Horiuti-Polanyi mechanism)
I would write that the mechanism of hydrogenation of olefins is still unknown. “Contact with a hydrogenation catalyst necessarily causes cis-trans-isomerization, because the isomerization is thermodynamically favorable.” However, according to the literature, the hydrogenation of C=C bond at low temperature is usually a syn-addition (especially on Pt, see for example Samuel Siegel and George S. McCaler, J. Am. Chem. Soc. 1959, 81, 14, 3655–3658). There are at least six other arguments that make the Horiuti-Polanyi mechanism questionable. More details on my website http://cz.9e.cz/cz-9e-cz/hgb/ Note: In my opinion, hydrogenation and isomerization during hydrogenation are probably independent parallel reactions: V.heral (talk) 12:42, 23 June 2021 (UTC)
 * I suppose the finest detail isn't understood, but roughly the molecule binds to the catalyst, which opens up the double bond. Then, maybe with hydrogen already on the catalyst surface, hydrogenates the bond. But all chemical reactions are reversible (though some with a high energy barrier). As well as I know it, after binding to the catalyst, it can release without hydrogenation, and often comes off trans. It might even be reversed after one hydrogen is attached.  From Le Chatelier's principle, increasing the pressure will move the equilibrium toward hydrogenation, but it also speeds up the process. So, recent technology reduces the amount of trans-fat generated. Maybe better catalysts, too. But before people knew that trans fats were bad, there was no reason to change things. Gah4 (talk) 02:05, 24 June 2021 (UTC)
 * I suppose the finest detail isn't understood, but roughly the molecule binds to the catalyst, which opens up the double bond. Then, maybe with hydrogen already on the catalyst surface, hydrogenates the bond. But all chemical reactions are reversible (though some with a high energy barrier). As well as I know it, after binding to the catalyst, it can release without hydrogenation, and often comes off trans. It might even be reversed after one hydrogen is attached.  From Le Chatelier's principle, increasing the pressure will move the equilibrium toward hydrogenation, but it also speeds up the process. So, recent technology reduces the amount of trans-fat generated. Maybe better catalysts, too. But before people knew that trans fats were bad, there was no reason to change things. Gah4 (talk) 02:05, 24 June 2021 (UTC)

only hydrocarbons
The first paragraph mentions hydrocarbons, but it also can be used to hydrogenate hydrocarbon parts of larger molecules, such as (as we well know) fats. Is there a more general word that can be used? Gah4 (talk) 21:58, 22 July 2021 (UTC)

syn addition
There is a question about syn addition. It seems that syn addition is important for cyclic molecules, where it can't rotate around the (single) bond after hydrogenation. As well as I know, that isn't usual in the case of hydrogenated fats, but then this article isn't specific to them. But I think the section mentioning syn addition should also mention that it applies for cyclic molecules. Gah4 (talk) 04:31, 8 February 2022 (UTC)

"Partially hydrogenated oil" listed at Redirects for discussion
The redirect [//en.wikipedia.org/w/index.php?title=Partially_hydrogenated_oil&redirect=no Partially hydrogenated oil] has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at  until a consensus is reached. Jay 💬 05:20, 6 August 2023 (UTC)

title: Talk:Hydrogenation


text:
Presidential line of succession

Presidential line of succession may refer to:

 * Brazilian presidential line of succession
 * Colombian presidential line of succession
 * Dominican presidential line of succession
 * Nigerian presidential line of succession
 * Philippine presidential line of succession
 * Sri Lankan presidential line of succession
 * United States presidential line of succession
 * Uruguayan presidential line of succession

title: Presidential line of succession