text:
Talk:Pebble-bed reactor

After reading still missing at least one important info
How does it work? Are the pebbles hot for themselves, the reaction occurs (mainly?) in the pebble, or are neutrons going from one pebble to others. If second case, how radioactive are the pebble before and after irradiation? And in this case, isnt there a possibility to stop the reaction in case of necessity in draining the core? If first case, are the pebble usable in little amounts like in a thermal-electricity-generator like those used in space? What is the operating life-length of a pebble? I think these are quite important topics that the reader wants to know... Pipecat (talk) 16:13, 15 April 2011 (UTC)

 * I believe you are confusing radioactive decay with nuclear fission. The PBR is a reactor, and has nuclear fission.  A "radioisotope thermoelectic generator" (RTG) has much smaller power densities as it uses decay heat for power.  A reactor also has a lot of radioactive decay, but this is more of a side-effect then the power source.  In fact, reactors are likely the source of radioisotopes for RTGs, depending on what type of radioisotope is being used.

 * The neutrons come from the coated particles dispersed in the pebbles. When neutrons are born, they have an average energy of 2 MeV.  Through collisions with other materials in the reactor core (principally the moderator), the neutrons will thermalize to .025 eV.  The neutron path will very likely travel outside the pebble it was born, but not necessarily.

 * Like all nuclear reactor fuel, pebbles are only slightly radioactive before irradiation (U-235 has an extremely long half-life), and very radioactive after due to the buildup of fission products.

 * "Draining the core" in order to stop the nuclear reaction is not necessary in a PBR, as the core is made of high temperature materials. In a core heat-up event, the negative thermal feedback will lower core power.  At low power and high temperatures, the core is designed to conduct all the heat through the vessel walls.  In fact, retaining pebbles in the core and suppressing natural circulation is seen as an attribute to protect the pebbles from air ingress events.

 * I expect the operating length of a pebble to be perhaps 3 years, but that depends on its initial enrichment and how high a burnup operators and regulators allow, and how much is useful.Ajnosek (talk) 23:17, 31 May 2011 (UTC)

"Written like an advert"
The company in South Africa that is developing the PBR always appear to gloss over the safety concerns in an attempt to minimize them in the eyes of the public. I personally think this technology is viable, but when playing with nuclear power, one shouldn't ever downplay the risks.

There is a strong likelihood that this Wikipedia article is being modified by a public relations company, or an expert in PR. —Preceding unsigned comment added by ObseloV (talk • contribs) 04:57, 21 January 2009 (UTC)

 * I agree that the language is not impartial. The content is informative, however. I don't know how much traffic will come from today's New York Times story, but I might put up a neutrality dispute sign and see what shakes out. - Cwmagee (talk) 05:22, 25 March 2011 (UTC)

Chicken McNuggets
For anyone who's wondering about the change in emphasis between the old reactors and the PBR designs, the PBR is using the "Chicken McNugget" business model, you put all your high technology investment up-front into the material manufacturing (the "pebble factory"), and then you can set up cheap franchised outlets wherever you want, taking delivery of the high-tech pebbles, bunging them into cheap reactors, and serving up hot and tasty electricity using staff who don't have to be geniuses, and who don't get the chance to do anything potentially dangerous.

Someone who used to design structural steelwork for UK reactors once said that they were designed like cathedrals: every one was different. It's like the restaurant business: you can have a single restaurant with specialist equipment and staff, all working together to create a great product and avoid food-poisoning disasters, but when it comes to franchising it, you have problems: You can't easily duplicate key staff, monitoring quality control through the chain is difficult (so you get stupid accidents) and you don't get bulk deals on the key equipment. You may get an economy of scale regarding know-how, but not for staff or hardware, because you aren't intending to build that many restaurants, and all your equipment is still very specialised.

The alternative is the McDonalds approach: to redesign the entire business model around mass production and franchising. Design once, build many (but spend a lot of money on the design). MacDonalds is the home of the Chicken McNugget: It takes a product that is variable and messy, and needs to be handled with care (chicken) and it turns it into a centrally-produced, encapsulated, idiot-proof format. You move all your high-tech staff and plant and specialist equipment into a central location where you use computers and robots and liquid nitrogen and god knows what else to churn out "nuggets", then you ship the nuggets to your local franchises, where the cheap staff dunk them in hot oil and serve them. The local staff never get to touch a knife or a piece of raw chicken themselves.

With cheap local staff and simple local plant, and there's a limit to how badly they can mess things up, because their job has already been made as simple as possible. You try to think of everything beforehand and streamline the local processes to be as close to idiot-proof as possible. The guys with the tough job are the ones back at the nugget factory (or the pebble factory) -- the cost and consistency of what happens there dictates the viability of the entire chain. If the mass-produced designs are right, and the product is designed well, the system runs smoothly and efficiently. If there's a problem at the nugget plant, it affects the whole chain. So it's critically important to get everything right (or nearly right) before you take the thing into mass-production.

This is why we haven't already had a big PBR roll-out: they want to hold off and make sure that they get it right, and then if a few pilot plants show that the model works, and there aren't any further cost or reliability issues with the pebbles ... poom ... the things will be everywhere. But the integrity, durability, reliability, manufacturing safety and cost of the pebbles themselves is critical. ErkDemon 16:22, 22 May 2007 (UTC)

 * A good essay. It leaves a few things out:

 * The standardisation of reactor designs isn't just a PBMR phenomenon, all reactor designers are doing it. It's part of the maturing of the industry, which may be about to put the "green" hiccup in the past and enter the boom that everyone in the 1950s thought was only 20 years away. I said may.

 * The pebble technology has applications in other reactor designs. If I were directing research, I'd be very interested in investigating a (slightly) higher-temperature Magnox-style plant using the cladding techniques that are involved in the pebbles... and looking at that sort of thing is very much part of the generation IV reactor project. The AGR would have been a world-beater if their original intention of using beryllium-based cladding had worked... but it didn't.

 * There are a number of sleeping problems political still to be encountered... the traditional ones of course are bombs, wastes and accidents. All three have the potential to scuttle the PBMR in favour of other designs (remember we are talking here about politics, not engineering):
 * Bombs - the pebble-bed concept lends itself to online refuelling, and even if the fuel pellets are reprocessing-proof, what's to stop you slipping in some fertile pellets that aren't? Made for it.
 * Because of online refuelling, you can keep the excess reactivity low. So, if someone is adding extra fertile pellets in, they will soak up noticeable amounts of neutrons, which will increase the amount of fuel used, so producing plutonium will either be slow or will be noticed. Jrincayc 01:52, 29 May 2007 (UTC)
 * That's the argument that is generally used. There are three problems with it. Firstly, it's a technical argument. Even if valid, frankly these subtleties have generally been lost on the antis. Secondly, it ignores the possibility that the operators will not care that they're being noticed, as happened with India. Thirdly and most important IMO, the point is not so much that the proliferation risk of a PBMR is all that high, it's rather that the risk however small is far greater than that posed by (say) a PWR or BWR - types which have both been resisted on the grounds of proliferation risk (however foolishly) - which gets us back to the politics. Our article on Nuclear fuel currently reads Reprocessing of spent commercial-reactor nuclear fuel has not been permitted in the United States due to nonproliferation considerations. That is high-burnup spent PWR and BWR fuel we are talking about there! Andrewa Andrewa 01:07, 31 May 2007 (UTC)
 * Wastes - the PBMR concept not only abandons recycling of uranium and transuranics, it also throws away the moderator. First proposed nuclear fuel cycle in history to produce more nuclear waste per megawatt-hour than a once-through Westinghouse PWR.
 * Accidents - Graphite-moderated reactors quite simply have the worst accident record of any moderator type, so far. Windscale, Chernobyl. TMI was a hiccup by comparison.

 * But I like your analysis. Interesting times. Andrewa 01:58, 26 May 2007 (UTC)

 * Though interesting, this is supposed to be a talk page about the article, not a discussion forum about the topic. There are lots of forums out there, only one Wikipedia though. Pro crast in a tor 10:06, 29 May 2007 (UTC)
 * Sorry, Wikipedia is not that special. theanphibian 19:16, 29 May 2007 (UTC)

 * I think that's a valid point... but one of the special things about Wikipedia is that we do have articles on current events and controversial topics, and we try to be NPOV even there. And it's a challenge at times! Where to draw the line? I think this essay is helpful, and suitable for a talk page, because I think it will help us to improve the article. But, if that's not the case, then you're quite right, it doesn't belong here. There are lots of interesting things that don't belong here. The acid test is simple: Will it help us to improve the articles? Andrewa 00:35, 31 May 2007 (UTC)

 * The topic was meant to prompt a few thoughts or discussions that might be useful to the development of the main page. But it ended up longer than intended, and if it isn't considered to be sufficiently useful I've no objection to it being deleted. All is happy! ErkDemon 00:33, 12 June 2007 (UTC)

 * As I said above, it will probably be archived eventually. Even if not, it will probably remain in the history.

 * Another interesting question that it raises... is the McNugget approach successful? In the 1970s I shared a house with other undergraduate university students, and one was working as a cook in a fast food chain. He would never eat there, he looked rather green when any of the rest of us did, and occasionally told stories which don't bear repeating to try to convince us not to either. The problem seeemd to be that the job was so simple, there was no sense of responsibility for the product. Some chains now appear to be quite intentionally working to correct this, to introduce some responsibility and accountability and even pride into jobs at all levels.

 * On the other extreme, one of the common strands to several nuclear reactor accidents (in particular SL-1 and Chernobyl) is that the operators had been told and believed that they couldn't break the reactor. The Soviets had been saying since the mid-1950s that their control systems were foolproof; This was their justification for building reactors of a type that the rest of the world thought dangerously unstable, and they were very proud of the achievement. And they'd evidently communicated this to the management and staff of Chernobyl NPP to the point that nobody was worried about conducting an experiment in the absence of anyone trained in nuclear engineering. The collegues of the three victims of the SL-1 accident have replied to suggestions that one of the victims might have deliberately lifted the control rod assembly in order to commit suicide by pointing out that in their training they were repeatedly told how safe the whole rig was, and that they doubted that any of them knew of the danger that this action posed. Presumably, the same helio belief in the inherent safety of SL-1 was behind the (in hindsight appalling) decision to have these people unbolting and manually operating the control rod without having a nuclear engineer present to supervise.

 * It's impossible to make anything foolproof, because fools are so ingenious. Andrewa 02:54, 3 July 2007 (UTC)
 * Firstly, the safety of HTRs is impeccable. Their safety has even been tested several times with accident conditions were ANY other nuclear reactor would have had a meltdown. Full control rod pull-out coupled with a complete shutdown of all cooling has been demonstrated several times in the AVR and the HT-10. HTRs are safe because no operator action is required to prevent the release of radioactive fission products.

 * There are two hypothetical accident cases situated around the inability to switch off the blowers. In these cases the staff has several hours time to switch off the blowers. That's why the ONLY safety grade equipment within the entire reactor are the switch-off controls for the blowers. And even then, there are multiple ways to switch something off, you know. Just get a fire axe and whack the power cable. You've got several hours time to do that...

 * Got a leak? No problem. Get a mechanic and weld a piece of metal above the hole once the core is depressurized to minimize future damage from air ingress. BTW, constructing a dangerous case wrt. to air ingress is more difficult than you think, it doesn't just happen with a hole...

 * The safety of the HTR is that if even only a fraction of the equipment works, and a severe accident happens, the staff can first have a lunch, then go down to the pub for a drink and then afterwards go on weekend trip, and NOTHING would happen. Sure the reactor would be scrap, but no release of fission products would occur. The only way that the core can overheat, and cause about one in a million fuel particles to break, resolves around the inability to switch the blower off during extremely severe accidents. And I am talking here about a terrorist-style-bombing-of-selected-components-extremely-severe accident...

 * Secondly about fuel waste. HTRs need much, much less fuel due to their insane burn-ups AND the uniformity of that burn-up within the spent fuel. Theoretically, one could mill the spent fuel and then do the usual reprocessing afterwards, but due to the extremely high burn-ups of HTRs this is highly uneconomical. Burn-ups around 200GWd/tHM in HTRs btw. translates to about 70-80% of all energy being created by fissioning breeded Plutonium. There is a reason why the US chose this reactor design to destroy Russian Plutonium: its simply insanely good in utilizing nuclear fuel. --Dio1982 (talk) 19:42, 31 January 2008 (UTC)

 * I just want to say, this is by far, one of the most interesting "article" I had read on wikipedia. It is quite POV, I agree, but man does it provide insight.  I guess that's the problem with POV, what some consider to be insightful would be considered to be total BS by others.  129.173.242.237 19:49, 5 November 2007 (UTC)

Reference 9 is missing
I just tried to access reference 9 but it appears to have 404d... 87.112.74.244 (talk) 11:46, 3 January 2008 (UTC)

Citation needed on public radiation release
In section Pebble_bed_reactor, it says: "Later problems with the AVR reactor resulted in a small release of radiation to the public."

I really think we need a citation for this event to clarify just how safe or unsafe these reactors are. I would also like to see information on exactly how "small" it was, if that information can be found.

The best reference I found in Googling is at the end of a page on how | pebbles circulate within the reactor, but it is still very vague, and not a very authoritative source. Another potential reference is | Reactor Watchdog Project's info page on PBMR, which has more detail, but also comes from a site with an obvious anti-nuclear spin.

It is also mentioned in THTR-300, but I don't see a citation there either.

Different sources identify the event as happening in 1986, 1988, or May 4, 1985.

Correct is May 4, 1986 —Preceding unsigned comment added by 80.137.39.188 (talk) 10:00, 14 October 2010 (UTC)

LeBleu (talk) 00:44, 4 February 2008 (UTC)

The NIRS is not a credible source. I have removed the link. —Preceding unsigned comment added by 70.162.2.55 (talk) 00:09, 17 November 2008 (UTC)

Also, it is very difficult to get exact information on these accidents, since most of them have to do with national security interests. 128.196.210.75 (talk) 22:35, 17 November 2008 (UTC)

 * Check Dr. Moormann's paper http://hdl.handle.net/2128/3136 Jrincayc (talk) 13:16, 18 November 2008 (UTC)

 * For the AVR, the best resource is probably "Decommissioning of the AVR Experimental Nuclear Power Plant, Disassembly of Plant Components and Entombment" by Arbeitsgemeinschaft Versuchsreaktor AVR in Nov 1991, available on the NEA cdrom http://www.nea.fr/abs/html/nea-1739.html. In it it states that the releases off site were less than 1 μSv/a from the exhaust air, 3.5 mSv/a at the edge of the fence when the plant was operating, and 0.42 mSv/a at the edge of the fence at worst when the plant was shutdown (due to some stored radioactive waste). Jrincayc (talk) 04:51, 27 November 2008 (UTC)

 * The initial quotation was incorrect. The AVR had no problems.  It was the THTR that had the pebble problem.  I would imagine there's a decommissioning white paper on the THTR out there that discusses the incident, but I cannot find anything in English. 70.162.2.55 (talk) 06:36, 3 December 2008 (UTC)

Neolithic nuclear reactors?
Articles like this give me the impression that potentially, a shaman would need merely mix a powdered mineral containing unenriched uranium with a pure lampblack in order to make an ever-burning fire. (Though some ill might have befallen some villagers burned with it, he can scarcely be blamed for the judgments of the gods) Is it plausible for people to have made reactors this way in Neolithic times? Wnt (talk) 22:06, 7 August 2008 (UTC)
 * Rather implausible. You might be able to do it with natural uranium, but you would need pure uranium, not uranium ore.  See Chicago Pile-1 and Natural nuclear fission reactor Jrincayc (talk) 04:02, 17 November 2008 (UTC)

burial at sea to disrupt thermoclines
A pile of "spent" pebbles will still get hot, right? It seems like if the issues with cesium and strontium leaking out could be resolved, one could dump them in a sea with circulation issues to circulate the water by heating the depths. 65.46.169.246 (talk) 15:07, 16 March 2011 (UTC)
 * It is unlikely that water cooling will be necessary to cool this type of spent fuel. Pebbles have relatively low power densities and are designed for high temperatures.  A better idea is to keep them away from possible corrosive environments like saltwater.Ajnosek (talk) 18:18, 19 August 2011 (UTC)

Dimensions of the pebbles
What are the typical dimensions of the pebbles used in such reactors? This should be included in the text of the Design section, as now it seems one can only roughly deduce their size by looking at one of the pictures. —Centrx→talk • 05:21, 18 November 2008 (UTC)

6 cm in diameter is what AVR, HTR-10 and THTR used. Other sizes have been discussed (Someone from MIT put out a paper on this, but I don't remember the exact reference Kadak and others 2004ish maybe?) The pdf you can get from http://hdl.handle.net/2128/3136 has the pebble dimensions on page 2 for AVR. Jrincayc (talk) 03:39, 20 November 2008 (UTC)

 * The pebble diameter for the AVR, THTR, HTR-10 as well as for the planned PBMR in South Africa and the planned HTR-PM in China are all 6cm. There is a lot of experience in manufacturing and handling as well as experimental data about the 6cm diameter pebbles due to the AVR and THTR program. There isn't really any benefit to changing this diameter in terms of reactor physics and thermohydraulics, but it would cause a significant amount of work in getting new reactors designed and licensed. --129.69.25.217 (talk) 12:36, 20 January 2009 (UTC)

Textual error?
Section "Safety Features", final paragraph contains the text "The graphite is the moderator for the reactor, and are strong containment vessels", which defies grammar and seems meaningless. —Preceding unsigned comment added by 212.159.59.5 (talk) 18:33, 27 February 2009 (UTC)

Lots of logic probelms. I think a lot of this was written by someone who wasn't that skilled at english and worked in a hurry. consider this last sentence that I found:

The THTR management continued to charge the Chernobyl fallout for all the contamination in the surrounding, until the presence of Pa-233 ... 233Pa is not formed in uranium reactors as Chernobyl, but only in thorium reactors .... Thus, step by step, the THTR management report was accurate.

I'll clean this up but a once-over by someone who knows would help. OsamaBinLogin (talk) 00:10, 21 May 2012 (UTC)

Cleaning up citations
There's a scattering of [citation needed] markers -- any chemists out there who can assist? E.g.:

 * in 'Containment', this might be appropriate for "Pyrolytic carbon can burn in air when the reaction is catalyzed by a hydroxyl radical (e.g. from water)". Is there a Chemistry Wikipedia group that could help? ThomasNichols (talk) 11:46, 6 October 2009 (UTC)

pebble leakage
This paragraph ...

"A pebble-bed reactor thus can have all of its supporting machinery fail, and the reactor will not crack, melt, explode or spew hazardous wastes. It simply goes up to a designed "idle" temperature, and stays there. In that state, the reactor vessel radiates heat, but the vessel and fuel spheres remain intact and undamaged. The machinery can be repaired or the fuel can be removed. These safety features were tested (and filmed) with the German AVR reactor.[10]. All the control rods were removed, and the coolant flow was halted. Afterward, the fuel balls were sampled and examined for damage and there was none."

... is in contrast to ...

"Darüber hinaus wurde im Jahre 2008 ein Bericht von Rainer Moormann, Mitarbeiter des FZJ, veröffentlicht, in dem die übermäßig starke radioaktive Kontamination des Reaktors auf eine unzureichende Überwachung des Reaktorkerns sowie einen länger andauernden Betrieb bei unzulässig hohen Temperaturen zurückzuführen ist. Dies habe u. a. dazu geführt, dass Spaltprodukte aus den Graphitkugeln austreten konnten."

... from http://de.wikipedia.org/wiki/AVR_%28J%C3%BClich%29, which translates to ...

Furthermore in 2008 Rainer Moormann, who works at the FZJ, published a report where the overly high contamination of the reactor was caused by inadequate monitoring of the reactor core as well as by lengthy operations at inadmissively high temperatures. This has among others led to the release of fission products from the graphite balls.

Is Rainer Moormann's report correct? Did the pebbles leak due to excess temperature? What is excess temperature? I thought the reactor can go up to idle temperature which is not excessive and safe. Or was the leakage caused by additionally leakage of water into the reactor? —Preceding unsigned comment added by Darsie42 (talk • contribs) 15:31, 18 July 2010 (UTC)

 * I think the excess temperature issues is a bit of a debate, that being how they happened, or even if they happened. I believe in-core temperature monitoring is difficult to do, and so they relied on ex-core monitoring to calculate the core temperature profiles.  Pebbles with melt wires were put into the reactor, and operators were surprised to find that the wires indicated higher than expected temperatures.  One hypothesis is that the pebbles travel through the core at different velocities, specifically slower velocities near the side.  Because of this, some areas have groups of pebbles with large burnups while other areas with relatively fresh fuel would have large temperatures and fluxes.
 * In addition, I also recall an issue where AVR (I believe AVR) was not designed with guidetubes for the control rods. When operators used the control rods, the rods would jam through the pebbles, breaking some.  This would contribute to fission product release, although I doubt this would effect the most significant barrier, that being the SiC layer of the TRISO fuel particles.  I do not know how much "leakage" occurred, perhaps enough to be significant in that it created some contamination, but perhaps not enough to develop into a safety concern.  AVR was a prototype reactor, and many of these types of lessons are the reasons for having prototypes.  What I know is mostly hearsay, so I don't feel it will be accurate enough to put in the article.   Ajnosek (talk) 18:44, 19 August 2011 (UTC)

Reference 6 missing
Reference 6 returns a 404 error mostly in German. Some sleuthing may be required to find the correct new link. —Preceding unsigned comment added by 65.160.229.33 (talk) 17:01, 14 March 2011 (UTC)

Control rods: Article contradicts itself
The article emphasizes at various spots that there are no control rods in this reactor design; however, later, it states:

"All the control rods were removed"

How does that fit together?

Intrr (talk) 19:14, 26 March 2011 (UTC)

Answer:

Every reactor design has some kind of manual mechanism to control neutron absorption. The most common is control rods inserted into the center of the reactor, alongside the fuel rods. In a pebble bed reactor, this is clearly not a good idea. The alternative is to surround the fuel area with neutron reflecting material, and alter this material in order to control the amount of neutrons in the core. One design uses rotating cylinders, which are neutron reflecting on one side, and neutron absorbing on the other. Another method would be to have a solid block of neutron reflecting material, with spaces where neutron absorbing material can be slid into place. These sliding neutron absorbers are different from conventional control rods, but could also be reasonable described as control rods. I do not see a contradiction here, just vagueness.

Probably the details of the PBR design should be researched, properly referenced and described. However, the information in the article regarding control rods seems basically correct, though technically vague. The article mentions the sliding neutron absorbers, but does not specifically say that the PBR design used them.

Anyway, the whole point of the PBR design is that conventional neutron control systems are not needed for safe operation. So this control rod discussion is not all that important.

-Anon, March 28

Combustible graphite
I would have to say that the statements about graphite burning are the results of original research. There are no citations regarding this. It was just presumed that because it was a form of Carbon that it would readily burn.

In fact, graphite is not combustible, or only slightly combustible at high temperatures. There is also pyrolytic Carbon that is also used in making TRISO fuel elements that is only combustible at high temperatures. Some actual research should be done on the subject regarding just how combustible graphite is under the temperature conditions in the reactor.

Tyrerj (talk) 06:00, 23 January 2015 (UTC)

 * Chernobyl. That is all.178.15.151.163 (talk) 15:12, 9 August 2016 (UTC)

The myth of using spent reactor fuel for nuclear weapons
The article says: "it is difficult to re-use pebble-bed reactor waste for nuclear weapons"

Since it is impossible to make nuclear weapons from reactor "waste", that really makes no difference. Reactor waste contains Plutonium. However, it is what is called reactor grade Plutonium. If you read Wikipedia, you will find that there is more than one isotope of Plutonium and that only Plutonium-239 is desirable for making weapons. Plutonium that contains over 10% of Plutonium-240 is simply not suitable for making weapons. The Plutonium in reactor waste not only contains more than that much 240 but also contains 241 and 242. I suggest that you do some research instead of repeating incorrect anti-nuclear propaganda.

Tyrerj (talk) 06:27, 23 January 2015 (UTC)

THTR-300 - Commission and 75 % of activity
"In spite of the limited amount of radioactivity released (0.1 GBq 60Co, 137Cs, 233Pa)a commission of inquiry was appointed. The radioactivity in the vicinity of the THTR-300 was finally found to result 25% from Chernobyl and 75% from THTR-300."

This is incorrect and probably a lie coming from an editor who should know the final report of that commission. It rejected all claims coming from anti-nuclear-power-activists regarding the 75 % as unfounded. It actually states that the activity in the vicinity coming from the plant was so small that it could not be measured and was not detected by the installed measuring stations and estimated it based on the measured emissions(!) of that week using a distribution model to be less than 1 Bq / m² of soil surface at maximum (while the immissions(!) coming from Chernobyl in that area at that time being around 10000 Bq / m²).

The final report of that commission:

https://www.landtag.nrw.de/portal/WWW/dokumentenarchiv/Dokument?Id=MMV10%2F561%7C1%7C0

Jwalter (talk) 08:24, 31 May 2016 (UTC)

Does pebble-bed include particle-bed
Project Timberwind used particle-bed reactor designs - are they considered pebble-bed reactors ? - Rod57 (talk) 17:40, 15 April 2021 (UTC)
 * I still don't know - but PB reactors seem to use 60mm diam 'pebble' elements, each containing many 1 mm diam coated fuel particles. - Rod57 (talk) 09:53, 9 October 2021 (UTC)

Reactor sketch - gas circulation direction?
There seems to be a problem with the sketch of the reactor. Where does it come from? There's no source listed. Here's what I found disturbing: the arrows that illustrate gas circulation and these arrows suggest that the cooling gas is forced down the pebble bed and then down through the heat exchanger which is the opposite of natural gas circulation due to temperature and density changes. Without pumping, the gas would heat and rise in the reactor and cool down and fall in the heat exchanger. This natural circulation seems like a fail-safe for the pumps. Also, forcing the flow down through the pebble bed could cause convection heat bubbles to form - the hotter the area, the more it would resist the forced downwards flow (the opposite would happen in the exchanger, though there the linear structure and coolant flow make it much less relevant). - not signed by User:78.11.145.7 06:18, 26 July 2021
 * The sketch may be based on similar in which has comments that also question the direction of gas flow. - Rod57 (talk) 09:00, 9 October 2021 (UTC)
 * has a more detailed diagram that also shows gas flow down in the chinese HTR-10, so I guess down is correct. That blog refs China 210 MWe pebble bed reactor starts construction April, 2011 which has more refs. - Rod57 (talk) 09:48, 9 October 2021 (UTC)
 * AVR reactor says its helium coolant flows UP through the core. - Rod57 (talk) 18:08, 9 October 2021 (UTC)

title: Talk:Pebble-bed reactor


text:
User:Ww

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title: User:Ww


text:
Hitachi 917

The Hitachi 917 is an automated biochemistry analyser utilise medical laboratories to process biological fluid specimens, such as urine, cerebrospinal fluid, and most commonly, blood.

Manufactured by Boehringer Mannheim, the Hitachi 917 is a commonly used routine chemical bichromatic analyser. Capable of doing 1200 test/hour with ISE, it is a popular choice among small to medium size laboratories.

Appearance and use
The 917 has two trays for racks, plus a stat rack. Racks that hold five test tubes slide in on the left side of the machine. There are two reagents carousels on the right side of the 917. In the centre, towards the back, are the reaction vessels, where the chemical reactions take place.

Features at a glance

 * Type:Chemistry Analyzer
 * Parameters: 86 analytes
 * Method: Spectrophotometric Method.
 * Weight: 455 kilos
 * W x D x H: 60x30x44 inches / 152x76x112 cm

Tests available

 * Ion selective electrodes (e.g. Na, K, Cl)
 * Rate (e.g. creatine kinase)
 * End point
 * Immunoturbidity

title: Hitachi 917


text:
Robert Maclennan, Baron Maclennan of Rogart

Robert Adam Ross "Bob" Maclennan, Baron Maclennan of Rogart, (26 June 1936 – 18 January 2020) was a British Liberal Democrat politician and life peer.

He was the last leader of the Social Democratic Party (SDP), serving during the negotiations that led to its merger with the Liberal Party in 1988. He then became joint interim leader of the new party, known as the Social and Liberal Democrats (SLD) and later as the Liberal Democrats. He served as a Member of Parliament (MP) from 1966 to 2001, when he was elevated to the House of Lords.

Early life
MacLennan was born in Glasgow in 1936. His father, Sir Hector MacLennan, was a renowned gynaecologist and obstetrician. His mother, Isabel Margaret (née Adam), was a physician and public health activist. He was the brother of actor and director David MacLennan, actress and writer Elizabeth MacLennan, and Kenneth MacLennan.

He was educated at Glasgow Academy; Balliol College, Oxford; Trinity College, Cambridge; and Columbia University, New York City. He was called to the bar in 1962 at Gray's Inn and before entering parliament practised as an international lawyer based in London. From 1963 to 1964, he worked at Sullivan & Cromwell in New York.

In Parliament
He became Member of Parliament (MP) for the constituency of Caithness and Sutherland in 1966, and serving until 1997; and for Caithness, Sutherland and Easter Ross after boundary changes, from 1997 to 2001.

He was first elected as a member of the Labour Party, where he was described as a "gentle Jenkinsite" and served as a junior minister in the Labour government of 1974–1979. In 1981 defected to become a founder member of the SDP, co-founded by Jenkins. Maclennan helped write the party's constitution. He was one of the few SDP MPs to keep their seats in the 1983 general election. After his stint as SDP Leader in 1988, he served as a front bench spokesman for the Liberal Democrats, and as their president from 1994 until 1998.

He was appointed to the Privy Council in 1997.

After his retirement at the 2001 general election, he was raised to the House of Lords, created a life peer as Baron Maclennan of Rogart, of Rogart in Sutherland. He was the party's Cabinet Office and Scotland spokesman in the House of Lords until 2015.

Personal life and death
In 1968, Maclennan married Helen Noyes (née Cutter), daughter of Justice Richard Ammi Cutter of the Massachusetts Supreme Judicial Court. As Maclennan's spouse she was Lady Maclennan of Rogart. She had one son from a previous marriage, and a son and a daughter with Maclennan.

Maclennan died at his home in the City of Westminster on 18 January 2020, at age 83.


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BMP file format

The BMP file format or bitmap, is a raster graphics image file format used to store bitmap digital images, independently of the display device (such as a graphics adapter), especially on Microsoft Windows and OS/2 operating systems.

The BMP file format is capable of storing two-dimensional digital images in various color depths, and optionally with data compression, alpha channels, and color profiles. The Windows Metafile (WMF) specification covers the BMP file format.

Device-independent bitmaps and the BMP file format
Microsoft has defined a particular representation of color bitmaps of different color depths, as an aid to exchanging bitmaps between devices and applications with a variety of internal representations. They called these device-independent bitmaps or DIBs, and the file format for them is called DIB file format or BMP image file format.

According to Microsoft support: "A device-independent bitmap (DIB) is a format used to define device-independent bitmaps in various color resolutions. The main purpose of DIBs is to allow bitmaps to be moved from one device to another (hence, the device-independent part of the name). A DIB is an external format, in contrast to a device-dependent bitmap, which appears in the system as a bitmap object (created by an application...). A DIB is normally transported in metafiles (usually using the StretchDIBits function), BMP files, and the Clipboard (CF_DIB data format)."

The following sections discuss the data stored in the BMP file or DIB in detail. This is the standard BMP file format. Some applications create bitmap image files which are not compliant with the Microsoft documentation. Also, not all fields are used; a value of 0 will be found in these unused fields.

File structure
The bitmap image file consists of fixed-size structures (headers) as well as variable-sized structures appearing in a predetermined sequence. Many different versions of some of these structures can appear in the file, due to the long evolution of this file format.

Referring to the diagram 1, the bitmap file is composed of structures in the following order:

DIBs in memory
A bitmap image file loaded into memory becomes a DIB data structure – an important component of the Windows GDI API. The in-memory DIB data structure is almost the same as the BMP file format, but it does not contain the 14-byte bitmap file header and begins with the DIB header. For DIBs loaded in memory, the color table can also consist of 16-bit entries that constitute indexes to the currently realized palette (an additional level of indirection), instead of explicit RGB color definitions. In all cases, the pixel array must begin at a memory address that is a multiple of 4 bytes. In non-packed DIBs loaded in memory, the optional color profile data should be located immediately after the color table and before the gap1 and pixel array (unlike in diag. 1).

When the size of gap1 and gap2 is zero, the in-memory DIB data structure is customarily referred to as "packed DIB" and can be referred to by a single pointer pointing to the beginning of the DIB header. In all cases, the pixel array must begin at a memory address that is a multiple of 4 bytes. In some cases it may be necessary to adjust the number of entries in the color table in order to force the memory address of the pixel array to a multiple of 4 bytes. For "packed DIBs" loaded in memory, the optional color profile data should immediately follow the pixel array, as depicted in diag. 1 (with gap1=0 and gap2=0). "Packed DIBs" are required by Windows clipboard API functions as well as by some Windows patterned brush and resource functions.

Bitmap file header
This block of bytes is at the start of the file and is used to identify the file. A typical application reads this block first to ensure that the file is actually a BMP file and that it is not damaged. The first 2 bytes of the BMP file format are the character "B" then the character "M" in ASCII encoding. All of the integer values are stored in little-endian format (i.e. least-significant byte first).

DIB header (bitmap information header)
This block of bytes tells the application detailed information about the image, which will be used to display the image on the screen. The block also matches the header used internally by Windows and OS/2 and has several different variants. All of them contain a dword (32-bit) field, specifying their size, so that an application can easily determine which header is used in the image. The reason that there are different headers is that Microsoft extended the DIB format several times. The new extended headers can be used with some GDI functions instead of the older ones, providing more functionality. Since the GDI supports a function for loading bitmap files, typical Windows applications use that functionality. One consequence of this is that for such applications, the BMP formats that they support match the formats supported by the Windows version being run. See the table below for more information.

The Windows 2.x BITMAPCOREHEADER differs from the OS/2 1.x BITMAPCOREHEADER (shown in the table above) in the one detail that the image width and height fields are signed integers, not unsigned.

Versions after BITMAPINFOHEADER only add fields to the end of the header of the previous version. For example: BITMAPV2INFOHEADER adds fields to BITMAPINFOHEADER, and BITMAPV3INFOHEADER adds fields to BITMAPV2INFOHEADER.

An integrated alpha channel has been introduced with the undocumented BITMAPV3INFOHEADER and with the documented BITMAPV4HEADER (since Windows 95) and is used within Windows XP logon and theme system as well as Microsoft Office (since v2000); it is supported by some image editing software, such as Adobe Photoshop since version 7 and Adobe Flash since version MX 2004 (then known as Macromedia Flash). It is also supported by GIMP, Google Chrome, Microsoft PowerPoint and Microsoft Word.

For compatibility reasons, most applications use the older DIB headers for saving files. With OS/2 no longer supported after Windows 2000, for now the common Windows format is the BITMAPINFOHEADER header. See next table for its description. All values are stored as unsigned integers, unless explicitly noted.

The compression method (offset 30) can be:

An OS/2 2.x OS22XBITMAPHEADER (BITMAPINFOHEADER2 in IBM's documentation) contains 24 additional bytes:

The halftoning algorithm (offset 60) can be:

Color table
The color table (palette) occurs in the BMP image file directly after the BMP file header, the DIB header, and after the optional three or four bitmasks if the BITMAPINFOHEADER header with BI_BITFIELDS (12 bytes) or BI_ALPHABITFIELDS (16 bytes) option is used. Therefore, its offset is the size of the BITMAPFILEHEADER plus the size of the DIB header (plus optional 12-16 bytes for the three or four bit masks). Note: On Windows CE the BITMAPINFOHEADER header can be used with the BI_ALPHABITFIELDS option in the biCompression member.

The number of entries in the palette is either 2n (where n is the number of bits per pixel) or a smaller number specified in the header (in the OS/2 BITMAPCOREHEADER header format, only the full-size palette is supported). In most cases, each entry in the color table occupies 4 bytes, in the order blue, green, red, 0x00 (see below for exceptions). This is indexed in the BITMAPINFOHEADER in the structure member biBitCount.

The color table is a block of bytes (a table) listing the colors used by the image. Each pixel in an indexed color image is described by a number of bits (1, 4, or 8) which is an index of a single color described by this table. The purpose of the color palette in indexed color bitmaps is to inform the application about the actual color that each of these index values corresponds to. The purpose of the color table in non-indexed (non-palettized) bitmaps is to list the colors used by the bitmap for the purposes of optimization on devices with limited color display capability and to facilitate future conversion to different pixel formats and palettization.

The colors in the color table are usually specified in the 4-byte per entry RGBA32 format. The color table used with the OS/2 BITMAPCOREHEADER uses the 3-byte per entry RGB24 format. For DIBs loaded in memory, the color table can optionally consist of 2-byte entries – these entries constitute indexes to the currently realized palette instead of explicit RGB color definitions.

Microsoft does not disallow the presence of a valid alpha channel bit mask in BITMAPV4HEADER and BITMAPV5HEADER for 1bpp, 4bpp and 8bpp indexed color images, which indicates that the color table entries can also specify an alpha component using the 8.8.8.[0-8].[0-8] format via the RGBQUAD.rgbReserved member. However, some versions of Microsoft's documentation disallow this feature by stating that the RGBQUAD.rgbReserved member "must be zero".

As mentioned above, the color table is normally not used when the pixels are in the 16-bit per pixel (16bpp) format (and higher); there are normally no color table entries in those bitmap image files. However, the Microsoft documentation (on the MSDN web site as of Nov. 16, 2010 ) specifies that for 16bpp (and higher), the color table can be present to store a list of colors intended for optimization on devices with limited color display capability, while it also specifies, that in such cases, no indexed palette entries are present in this Color Table. This may seem like a contradiction if no distinction is made between the mandatory palette entries and the optional color list.

Pixel storage
The bits representing the bitmap pixels are packed in rows (also known as strides or scan lines). The size of each row is rounded up to a multiple of 4 bytes (a 32-bit DWORD) by padding.

For images with height above 1, multiple padded rows are stored consecutively, forming a Pixel Array.

The total number of bytes necessary to store one row of pixels can be calculated as: $$\text{RowSize} = \left\lceil\frac { \text{BitsPerPixel} \cdot \text{ImageWidth}}{32}\right\rceil \cdot 4 = \left\lfloor\frac { \text{BitsPerPixel} \cdot \text{ImageWidth}+31}{32}\right\rfloor \cdot 4,$$

ImageWidth is expressed in pixels. The equation above uses the floor and ceiling functions.

The total number of bytes necessary to store an array of pixels in an n bits per pixel (bpp) image, with 2n colors, can be calculated by accounting for the effect of rounding up the size of each row to a multiple of 4 bytes, as follows:

$$\text{PixelArraySize} = \text{RowSize} \cdot |\text{ImageHeight}|$$

ImageHeight is expressed in pixels. The absolute value is necessary because ImageHeight is expressed as a negative number for top-down images.

Pixel array (bitmap data)
The pixel array is a block of 32-bit DWORDs, that describes the image pixel by pixel. Usually pixels are stored "bottom-up", starting in the lower left corner, going from left to right, and then row by row from the bottom to the top of the image. Unless BITMAPCOREHEADER is used, uncompressed Windows bitmaps also can be stored from the top to bottom, when the Image Height value is negative.

In the original OS/2 DIB, the only four legal values of color depth were 1, 4, 8, and 24 bits per pixel (bpp). Contemporary DIB Headers allow pixel formats with 1, 2, 4, 8, 16, 24 and 32 bits per pixel (bpp). GDI+ also permits 64 bits per pixel.

Padding bytes (not necessarily 0) must be appended to the end of the rows in order to bring up the length of the rows to a multiple of four bytes. When the pixel array is loaded into memory, each row must begin at a memory address that is a multiple of 4. This address/offset restriction is mandatory only for Pixel Arrays loaded in memory. For file storage purposes, only the size of each row must be a multiple of 4 bytes while the file offset can be arbitrary. A 24-bit bitmap with Width=1, would have 3 bytes of data per row (blue, green, red) and 1 byte of padding, while Width=2 would have 6 bytes of data and 2 bytes of padding, Width=3 would have 9 bytes of data and 3 bytes of padding, and Width=4 would have 12 bytes of data and no padding.

Compression

 * Indexed color images may be compressed with 4-bit or 8-bit RLE or Huffman 1D algorithm.
 * OS/2 BITMAPCOREHEADER2 24bpp images may be compressed with the 24-bit RLE algorithm.
 * The 16bpp and 32bpp images are always stored uncompressed.
 * Note that images in all color depths can be stored without compression if so desired.

Pixel format

 * The 1-bit per pixel (1bpp) format supports 2 distinct colors, (for example: black and white). The pixel values are stored in each bit, with the first (left-most) pixel in the most-significant bit of the first byte. Each bit is an index into a table of 2 colors. An unset bit will refer to the first color table entry, and a set bit will refer to the last (second) color table entry.
 * The 2-bit per pixel (2bpp) format supports 4 distinct colors and stores 4 pixels per 1 byte, the left-most pixel being in the two most significant bits (Windows CE only: ). Each pixel value is a 2-bit index into a table of up to 4 colors.
 * The 4-bit per pixel (4bpp) format supports 16 distinct colors and stores 2 pixels per 1 byte, the left-most pixel being in the more significant nibble. Each pixel value is a 4-bit index into a table of up to 16 colors.
 * The 8-bit per pixel (8bpp) format supports 256 distinct colors and stores 1 pixel per 1 byte. Each byte is an index into a table of up to 256 colors.
 * The 16-bit per pixel (16bpp) format supports 65536 distinct colors and stores 1 pixel per 2-byte WORD. Each WORD can define the alpha, red, green and blue samples of the pixel.
 * The 24-bit per pixel (24bpp) format supports 16,777,216 distinct colors and stores 1 pixel value per 3 bytes. Each pixel value defines the red, green and blue samples of the pixel (8.8.8.0.0 in RGBAX notation). Specifically, in the order: blue, green and red (8 bits per each sample).
 * The 32-bit per pixel (32bpp) format supports 4,294,967,296 distinct colors and stores 1 pixel per 4-byte DWORD. Each DWORD can define the alpha, red, green and blue samples of the pixel.

In order to resolve the ambiguity of which bits define which samples, the DIB headers provide certain defaults as well as specific BITFIELDS, which are bit masks that define the membership of particular group of bits in a pixel to a particular channel. The following diagram defines this mechanism:

The sample fields defined by the BITFIELDS bit masks have to be contiguous and non-overlapping, but the order of the sample fields is arbitrary. The most ubiquitous field order is: Alpha, Blue, Green, Red (MSB to LSB). The red, green and blue bit masks are valid only when the Compression member of the DIB header is set to BI_BITFIELDS. The alpha bit mask is valid whenever it is present in the DIB header or when the Compression member of the DIB header is set to BI_ALPHABITFIELDS (Windows CE only).

RGB video subtypes
The BITFIELD mechanism described above allows for the definition of tens of thousands of different pixel formats, however only several of them are used in practice, all palettized formats RGB8, RGB4, and RGB1 (marked in yellow in the table above, defined in .MEDIASUBTYPE names):

In version 2.1.4 FFmpeg supported (in its own terminology) the BMP pixel formats bgra, bgr24, rgb565le, rgb555le, rgb444le, rgb8, bgr8, rgb4_byte, bgr4_byte, gray, pal8, and monob; i.e., bgra was the only supported pixel format with transparency.

Example 1
Following is an example of a 2×2 pixel, 24-bit bitmap (Windows DIB header BITMAPINFOHEADER) with pixel format RGB24.

Example 2
Following is an example of a 4×2 pixel, 32-bit bitmap with opacity values in the alpha channel (Windows DIB Header BITMAPV4HEADER) with pixel format ARGB32.

Note that the bitmap data starts with the lower left hand corner of the image.

Usage of BMP format
The simplicity of the BMP file format, and its widespread familiarity in Windows and elsewhere, as well as the fact that this format is relatively well documented and has an open format, makes BMP a very common format that image processing programs from many operating systems can read and write. ICO and CUR files contain bitmaps starting with a BITMAPINFOHEADER.

Many older graphical user interfaces used bitmaps in their built-in graphics subsystems; for example, the Microsoft Windows and OS/2 platforms' GDI subsystem, where the specific format used is the Windows and OS/2 bitmap file format, usually named with the file extension of.

While most BMP files have a relatively large file size due to lack of any compression (or generally low-ratio run-length encoding on palletized images), many BMP files can be considerably compressed with lossless data compression algorithms such as ZIP because they contain redundant data. Some formats, such as RAR, even include routines specifically targeted at efficient compression of such data.

Related formats
The X Window System uses a similar XBM format for black-and-white images, and XPM (pixelmap) for color images. There are also a variety of "raw" formats, which save raw data with no other information. The Portable Pixmap (PPM) and Truevision TGA formats also exist, but are less often used – or only for special purposes; for example, TGA can contain transparency information.

title: BMP file format


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Marilyn Bowering

Marilyn Bowering (born April 13, 1949) is a Canadian poet, novelist and playwright. As well as several adventure novels and many books of poetry, Bowering has also scripted a number of dramatic works and a libretto.

Personal life
Bowering was born in Winnipeg, Manitoba, and grew up in Victoria, British Columbia. She studied English at the University of Victoria, and graduated with a Master of Arts degree.

Bowering presently lives in Sooke, British Columbia; she is married and has one daughter.

Career
In 1987, Bowering wrote a book of poetic monologues, titled Anyone Can See I Love You, which was later adapted as a radio drama. In 1998 she wrote an adventure story, Visible Worlds, which received positive reviews.

In 2012, her book of poetry, Soul Mouth, was published.

In 2013 Bowering worked with composer Gavin Bryars to create the libretto for a chamber opera, Marilyn Forever, about Marilyn Monroe.

Awards and honours

 * National Magazine Award for Poetry, Gold 1978
 * Nominated for the 1984 Governor General's Award (The Sunday Before Winter)
 * National Magazine Award for Poetry, Silver 1989
 * Long Poem Prize, The Malahat Review, 1994
 * Pat Lowther Award for poetry, 1997 (Autobiography)
 * Nominated for the 1997 Governor General's Award (Autobiography)
 * Nominated for the 1997 Dorothy Livesay Poetry Prize (Autobiography)
 * Ethel Wilson Fiction Prize, 1998 (Visible Worlds)
 * Short-listed for the Orange Prize, 1999 (Visible Worlds)
 * Short-listed for the Dorothy Livesay Poetry Prize, 2004 (The Alchemy of Happiness)
 * Short-listed for the Ethel Wilson Fiction Prize 2007 (What It Takes to Be Human)

Novels

 * The Visitors Have All Returned - 1979
 * To All Appearances a Lady - 1989
 * Visible Worlds - 1997
 * Cat's Pilgrimage - 2004
 * What It Takes to Be Human - 2007

Poetry

 * The Liberation of Newfoundland - 1973
 * One Who Became Lost - 1976
 * The Killing Room - 1977
 * The Book of Glass- 1978
 * Sleeping With Lambs - 1980
 * Giving Back Diamonds - 1982
 * The Sunday Before Winter - 1984
 * Grandfather was a Soldier - 1987
 * Anyone Can See I Love You - 1987
 * Calling All the World - 1989
 * Love As It Is - 1993
 * Autobiography - 1996
 * Human Bodies: Collected Poems 1987-1999 - 1999
 * The Alchemy of Happiness - 2003
 * Green - 2007
 * Soul Mouth - 2012
 * Threshold - 2015

Other

 * Many Voices, An anthology of contemporary Canadian Indian Poetry, co-edited with D. Day. - 1977
 * In Fine Form: The Canadian Book of Form Poetry, edited by Kate Braid and Sandy Shreve - 2005

Drama

 * Anyone Can See I Love You - 1988
 * Hajimari-No-Hajimari, four myths of the Pacific Rim - 1986
 * Temple of the Stars - 1996

Radio

 * Grandfather was a Soldier - 1983
 * Anyone Can See I Love You - 1986
 * Laika and Folchakov, a Journey in Time and Space - 1987
 * A Cold Departure, the Liaison of George Sand and Frederic Chopin -1989

title: Marilyn Bowering


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Loreena McKennitt

Loreena Isabel Irene McKennitt (born February 17, 1957) is a Canadian singer-songwriter, multi-instrumentalist, and composer who writes, records, and performs world music with Celtic and Middle Eastern influences. McKennitt is known for her refined and clear soprano vocals. She has sold more than 14 million records worldwide.

Early life and education
McKennitt was born in Morden, Manitoba, of Irish and Scottish descent to parents Jack McKennitt (died 1992) and Irene née Dickey (1931–2011). In Morden, she developed her love for music, influenced, in part, by the musical traditions of the local Mennonite community.

McKennitt enrolled at the University of Manitoba in Winnipeg to become a veterinarian. While in Winnipeg she discovered folk music, including fellow Canadians Neil Young, Joni Mitchell, and Gordon Lightfoot. After performing at the inaugural Winnipeg Folk Festival in 1974, McKennitt developed an interest in Celtic music and visited Ireland to hear it for herself. Developing a passion for Celtic music, she learned to play the Celtic harp and began busking at various places, including St. Lawrence Market in Toronto to earn money to record her first album.

In 1981, she moved to Stratford, Ontario, to join the Stratford Festival acting company, and still resides there.

Initial success: 1985–1998
McKennitt's first album, Elemental, was released in 1985, followed by To Drive the Cold Winter Away (1987), Parallel Dreams (1989), The Visit (1991), The Mask and Mirror (1994), A Winter Garden (1995), and The Book of Secrets (1997). All of her work is released under her own label, Quinlan Road.

In 1990, McKennitt provided the music for the National Film Board of Canada documentary The Burning Times, a feminist revisionist account of the Early Modern European witchcraft trials. She and the musical team she headed would later re-record the documentary's main theme on her album The Visit under the title "Tango to Evora".

In 1993, she toured Europe supporting Mike Oldfield. In 1995, her version of the traditional Irish song "Bonny Portmore" was featured in the Highlander series, followed by the 1994 film Highlander 3: The Sorcerer. McKennitt's single "The Mummers' Dance" received airplay in North American markets during the spring of 1997, and was used as the theme song for the short-lived TV series Legacy. It also saw use in the trailer for a wide-release 1998 Drew Barrymore film Ever After.

Her music appeared in the movies The Santa Clause, Soldier, Jade, Holy Man, The Mists of Avalon, and Tinker Bell. It was also featured in the television series Roar, Due South, and Full Circle (Women and Spirituality).

Personal tragedy and hiatus
In July 1998, McKennitt's fiancé Ronald Rees, his brother Richard, and their close friend Gregory Cook drowned in a boating accident on Georgian Bay. She was deeply affected by the event, and she founded the Cook-Rees Memorial Fund for Water Search and Safety in the same year. At the time of the incident, she was working on a live album of two performances called Live in Paris and Toronto. The proceeds from this album were donated to the newly created memorial fund, totalling some three million dollars.

After the release of the live album, McKennitt decided that she would substantially reduce the number of her public performances, and she did not release any new recordings until the studio album An Ancient Muse in 2006.

Return to music: 2006–present
During 2005, McKennitt began working on the album An Ancient Muse, her seventh full-length studio album, released in November 2006. In September 2006, she performed live at the Alhambra in Spain. The performance premiered on PBS and in August 2007 was released on a three-disc DVD/CD set titled Nights from the Alhambra.

In 2008, McKennitt wrote and composed "To the Fairies They Draw Near" for the theme song for Disney's direct-to-video animated film Tinker Bell. She also provided the narration for the film.

In early 2008, she returned to Peter Gabriel's Real World Studios to record A Midwinter Night's Dream, an extended version of her 1995 mini-album A Winter Garden: Five Songs for the Season. The album was released on October 28, 2008.

Since the release of An Ancient Muse, McKennitt has toured consistently, in Europe and North American, including the An Ancient Muse tour in 2007, another extensive tour across Canada and United States later in 2007, a tour of Europe in 2008 and a Mediterranean tour in 2009 with stops in Greece, Turkey, Cyprus, Lebanon, Hungary and Italy.

On September 17, 2009, McKennitt announced the release of a two-disc album, A Mediterranean Odyssey. The first CD, "From Istanbul to Athens", consisted of 10 new live recordings from her 2009 Mediterranean tour, including songs she had never before recorded in concert. The second CD, "The Olive and the Cedar", had a Mediterranean theme which McKennitt herself curated. It contained previously released studio recordings created between 1994 and 2006.

November 16, 2010, saw the US release (November 12 for Europe) of McKennitt's studio album, The Wind That Shakes the Barley. Recorded at the Sharon Temple in Ontario, the album comprises nine traditional Celtic songs.

When McKennitt released The Wind that Shakes the Barley she visited several countries to help promote the album. During the promotional tour she performed an hour-long concert in the studios of German radio station SWR1, accompanied only by Brian Hughes (guitars) and Caroline Lavelle (cello) who have long been part of her tours and recordings. This live concert was released on CD in 2011. Called Troubadours on the Rhine, the album was nominated for a 2012 Grammy for Best New Age Album.

On November 30, 2012, McKennitt lent her support to Kate Winslet's Golden Hat Foundation together with Tim Janis, Sarah McLachlan, Andrea Corr, Hayley Westenra, the Sleepy Man Banjo Boys, Dawn Kenney, Jana Mashonee, Amy Petty, and a choir, along with others, performing on "The American Christmas Carol" concert at Carnegie Hall.

McKennitt's 10th studio album, Lost Souls, was released on May 11, 2018. She planned a tour to support the album's release in 2018 and 2019.

She had a small acting role in the 2018 film Road to the Lemon Grove, as the voice of God.

In 2019, McKennitt released the live album Live at the Royal Albert Hall, recorded earlier that year in London.

Genre
McKennitt's music has generally been classified as World or Celtic music even though it contains aspects and characteristics of music from around the globe and is sometimes classified as folk music in record stores.

McKennitt is occasionally compared to Enya, but McKennitt's music is more grounded in traditional and classical invocations, using literary works as sources of lyrics and springboards for interpretation such as "The Lady of Shalott" by Lord Tennyson, "Prospero's Speech" (the final soliloquy in William Shakespeare's The Tempest), the Northumbrian murder ballad "The Twa Sisters" (which inspired "The Bonny Swans" on The Mask and Mirror), "Snow" by Archibald Lampman, "Dark Night of the Soul" by St. John of the Cross, Dante's Inferno, William Blake's "Lullaby", Yeats' "The Stolen Child," "The English Ladye and the Knight" by Sir Walter Scott, and "The Highwayman" by Alfred Noyes.

Influences
Before McKennitt composes any music, she engages in considerable research on a specific subject which then forms the general concept of the album. Before creating Elemental and Parallel Dreams, she travelled to Ireland for inspiration from the country's history, folklore, geography and culture. The album The Mask and Mirror was preceded by research in Spain where she studied Galicia, a Celtic section of Spain, along with its abundant Arabic roots. The result was an album that included elements of Celtic and Arabic music. According to the jacket notes, her album An Ancient Muse was inspired by travels among and reading about the various cultures along the Silk Road.

Documentaries
Late in the 1990s, McKennitt created No Journey's End, a half-hour documentary, for American television in which she discussed the influences behind her music. No Journey's End contained excerpts from several songs from the albums Parallel Dreams, The Visit, and The Mask and Mirror It also shows live performances of the songs "The Lady of Shalott", "Santiago", and "The Dark Night of the Soul". It was later released on DVD and VHS, the former also containing music videos for "The Mummers' Dance" and "The Bonny Swans." A bonus copy of the DVD was included with the 2004 remastered versions of McKennitt's CDs.

In 2008, McKennitt released A Moveable Musical Feast, based on her 2007 An Ancient Muse tour. The DVD included interviews with McKennitt, her band, crew, fans and professional colleagues from the Canadian music industry.

Court case
In 2005, McKennitt was involved in an acrimonious court case in England when her former friend and employee, Niema Ash, published a book, Travels with Loreena McKennitt: My Life as a Friend, that contained intimate details of their friendship. McKennitt argued that much of the book contained confidential personal information that Ash had no right to publish. The English courts found that there had indeed been a breach of confidence and a misuse of McKennitt's private information, and the case set important precedents in the law of England and Wales on the privacy of public figures. The House of Lords affirmed the lower court's decisions in 2007.

Honours

 * Juno Award, Best Roots/Traditional Album 1992, for The Visit
 * Juno Award, Best Roots/Traditional Album 1994, for The Mask and Mirror
 * Billboard Music Award for International Achievement, 1997
 * Honorary Doctor of Letters, Wilfrid Laurier University, 2002
 * Honorary Doctor of Laws, University of Manitoba, June 2005
 * Canadian Ambassador, Hans Christian Andersen Bicentenary, June 2005
 * Honorary Doctor of Laws, Queen's University, October 2005
 * Investiture as Honorary Colonel, 435 Transport and Rescue Squadron, Royal Canadian Air Force, December 2006
 * Nominated for a Grammy award, Best Contemporary World Music Album, in 2007
 * Western Canadian Music Awards Lifetime Achievement Award, September 2009
 * Performed at Vancouver 2010 Winter Olympics, Opening Ceremonies, February 12, 2010
 * Honorary Bachelor of Applied Business, George Brown College, June 2010
 * Nominated for a Grammy award, Best New Age Album, in 2012
 * Appointment as Honorary Colonel of the Royal Canadian Air Force, September 2014
 * Inductee, Canadian Songwriters Hall of Fame, 2023
 * Joseph-Elzéar Bernier Medal, Royal Canadian Geographical Society, 2023

Awards and decorations
McKennitt's personal awards and decorations include the following:

Order of Canada (CM) ribbon bar.png Order Manitoba ribbon bar.svg

UK Queen Elizabeth II Golden Jubilee Medal ribbon.svg QEII Diamond Jubilee Medal ribbon.svg CAN Canadian Forces Decoration ribbon.svg Ordre des Arts et des Lettres Chevalier ribbon.svg

Quinlan Road
Quinlan Road is an independent record label founded in 1985 and based in Stratford, Ontario, Canada. It is owned and operated by its sole artist, Loreena McKennitt. Quinlan Road started out at McKennitt's home where she sold recordings by mail order. Today Quinlan Road music is distributed internationally by Universal Music Group.

Videos

 * The Mummers' Dance (1997)
 * The Bonny Swans
 * Nights from the Alhambra (2007, live concert in Spain premiered on PBS)
 * A Moveable Musical Feast (2008, a tour documentary from Loreena's 2007 North American Tour)

Other

 * No Journey's End (half-hour profile, aired on PBS; DVD)
 * Heaven on Earth (TV movie 1987 – played "Lady Traveler")
 * Highlander III: The Sorcerer (Soundtrack contribution)
 * The Santa Clause (Soundtrack contribution, "The Bells of Christmas")
 * Léolo (Soundtrack contribution)
 * Una casa con vista al mar (Soundtrack contribution)
 * The Mists of Avalon (Soundtrack use)
 * The Burning Times (Soundtrack contribution)
 * Due South (Soundtrack use)
 * Northern Exposure (Soundtrack use)
 * Tinker Bell (Direct-to-DVD movie, 2008 – Narrator)
 * Soldier (Soundtrack use)

title: Loreena McKennitt


text:
Norman Lockyer

Sir Joseph Norman Lockyer (17 May 1836 – 16 August 1920) was an English scientist and astronomer. Along with the French scientist Pierre Janssen, he is credited with discovering the gas helium. Lockyer also is remembered for being the founder and first editor of the influential journal Nature.

Biography
Lockyer was born in Rugby, Warwickshire. His early introduction to science was through his father, who was a pioneer of the electric telegraph. After a conventional schooling supplemented by travel in Switzerland and France, he worked for some years as a civil servant in the British War Office. He settled in Wimbledon, South London after marrying Winifred James, who helped translate at least four French scientific works into English. He was a keen amateur astronomer with a particular interest in the Sun. In 1885 he became the world's first professor of astronomical physics at the Royal College of Science, South Kensington, now part of Imperial College. At the college, the Solar Physics Observatory was built for him and here he directed research until 1913.

In the 1860s Lockyer became fascinated by electromagnetic spectroscopy as an analytical tool for determining the composition of heavenly bodies. He conducted his research from his new home in West Hampstead, with a $6 1/4$-inch telescope which he had already used in Wimbledon.

In 1868 a prominent yellow line was observed in a spectrum taken near the edge of the Sun. Its wavelength was about 588 nm, slightly less than the so-called "D" lines of sodium. The line could not be explained as due to any material known at the time, and so it was suggested by Lockyer, after he had observed it from London, that the yellow line was caused by an unknown solar element. He named this element helium after the Greek word 'Helios' meaning 'sun'. An observation of the new yellow line had been made earlier by Janssen at the 18 August 1868 solar eclipse , and because their papers reached the French academy on the same day, he and Lockyer usually are awarded joint credit for helium's discovery. Terrestrial helium was found about 27 years later by the Scottish chemist William Ramsay. In his work on the identification of helium, Lockyer collaborated with the noted chemist Edward Frankland.

To facilitate the transmission of ideas between scientific disciplines, Lockyer established the general science journal Nature in 1869. He was elected as a member of the American Philosophical Society in 1874. He remained its editor until shortly before his death.

Lockyer led eight expeditions to observe solar eclipses for example in 1870 to Sicily, 1871 to India and 1898 to India.

Lockyer is among the pioneers of archaeoastronomy. Travelling 1890 in Greece he noticed the east–west orientation of many temples, in Egypt he found an orientation of temples to sunrise at midsummer and towards Sirius. Assuming orientation of the Heel-Stone of Stonehenge to sunrise at midsummer he calculated the construction of the monument to have taken place in 1680 BC. Radiocarbon dating in 1952 gave a date of 1800 BC. He also confirmed the alignment of the Parthenon on the rising point of the Pleiades and did extensive work on the solar and stellar alignments of Egyptian temples and their dating, presented in his book The Dawn Of Astronomy. Lockyer's first wife Winifred née James died in 1879. They had six sons and two daughters in all. In 1903, Lockyer started a second marriage, to suffragist Thomazine Mary Brodhurst (née Browne). After his retirement in 1913, Lockyer established an observatory near his home in Salcombe Regis near Sidmouth, Devon. Originally known as the Hill Observatory, the site was renamed the Norman Lockyer Observatory after his death and directed by his fifth son William J.S. Lockyer. For a time the observatory was a part of the University of Exeter, but is now owned by the East Devon District Council, and run by the Norman Lockyer Observatory Society. The Norman Lockyer Chair in Astrophysics at the University of Exeter is currently held by Professor Tim Naylor, who is the member of the Astrophysics group there which studies star formation and extrasolar planets. Naylor was the lead scientist for the eSTAR Project.

Lockyer died at his home in Salcombe Regis in 1920, and was buried there in the churchyard of St Peter and St Mary.

Publications

 * (1868–94)
 * Questions on Astronomy (1870)
 * (1873)
 * (1873)
 * (1878)
 * (1878)
 * Report to the Committee on Solar Physics on the Basic Lines Common to Spots and Prominences (1880)
 * (1887)
 * (1887)
 * (1890)
 * Penrose, F.C., (communicated by Joseph Norman Lockyer), The Orientation of Greek Temples, Nature, v.48, n.1228, 11 May 1893, pp. 42–43
 * (1894)
 * Norman Lockyer; William Rutherford (1896). The Rules of Golf: Being the St. Andrews Rules for the Game. Macmillan & Co.
 * (1897)
 * Recent and Coming Eclipses (1900)
 * (1900)
 * (1903)
 * Stonehenge and Other British Stone Monuments Astronomically Considered (1906; second edition, 1909)
 * (1907)
 * (1909)
 * (1910)

Honours and awards

 * Fellow of the Royal Society (1869)
 * Rumford Medal, Royal Society of London (1874)
 * Janssen Medal, Paris Academy of Sciences (1889)
 * Knight Commander of the Order of the Bath (1897)
 * President, British Association (1903 – 1904)
 * The crater Lockyer on the Moon and the crater Lockyer on Mars are both named after him, as is Norman Lockyer Island in Nunavut, Canada.

title: Norman Lockyer


text:
Demarcation point

In telephony, the demarcation point is the point at which the public switched telephone network ends and connects with the customer's on-premises wiring. It is the dividing line which determines who is responsible for installation and maintenance of wiring and equipment—customer/subscriber, or telephone company/provider. The demarcation point varies between countries and has changed over time.

Demarcation point is sometimes abbreviated as demarc, DMARC, or similar. The term MPOE (minimum or main point of entry) is synonymous, with the added implication that it occurs as soon as possible upon entering the customer premises. A network interface device often serves as the demarcation point.

History
Prior to Federal Communications Commission (FCC) regulations separating the ownership of customer premises telecommunication equipment from the telephone network, there was no need for a public standard governing the interconnection of customer premises equipment (CPE) to the United States' telephone network, since both the devices and the “local loop” wiring to the central office were owned and maintained by the local telephone company. Concurrent with the transfer of existing "embedded" CPE to the customer (customers could buy new telephones at retail or could continue to lease their existing equipment from the company), it was necessary to provide a standardized way to connect equipment, and also provide a way to test the phone company's service separately from the customer's equipment.

The ability of customers to buy and maintain their CPE and attach it to the network was stimulated by lawsuits by equipment manufacturers, such as the Hush-a-Phone v. FCC suit. Additionally, computer companies’ ability to offer enhanced services to customers was likewise constrained by the telephone companies’ control of all devices connected to the network. As the Bell telephone companies were themselves restricted from offering such enhanced services, there was little momentum to advance the state of the art.

The newly developed equipment-network separation was codified in Part 68 of the Code of Federal Regulations in the United States and later in comparable regulatory standards in other countries.

The physical and electrical interconnection is called the demarcation point, or Demarc, which includes one or more customer-accessible jack interfaces; previously, the interface was typically hard-wired and often in a telephone company-owned locked enclosure.

The premises-vs.-network separation in the United States, insofar as it affected the former Bell System, was independent of AT&T's divestiture of the local telephone companies on January 1, 1984. However, CPE interconnection and Bell System divestiture were part of a larger restructuring of the domestic telecommunications industry which took place during the 1980s and are commonly, if inaccurately, seen as one event. The historical Bell System domination of the United States telecommunications industry was also the de facto standard for other telephone companies such as GTE and other “independent” telephone companies.

Canada
The demarcation point varies from building type and service level. In its simplest form, the demarcation point is a junction block where telephone extensions join to connect to the network. This junction block usually includes a lightning arrester (which requires a wire to ground). In multi-line installations such as businesses or apartment buildings, the demarcation point may be a punch down block. In most places this hardware existed before deregulation.

United States
In the United States, the modern demarcation point is a device defined by FCC rules (47 C.F.R. Part 68) to allow safe connection of third-party telephone customer-premises equipment and wiring to the Public Switched Telephone Network (PSTN).

The modern demarcation point is the network interface device (NID) or intelligent network interface device (INID) also known as a "smartjack". The NID is the telco's property. The NID may be outdoors (typically, mounted on the building exterior in a weatherproof box) or indoors.

The NID is usually placed for easy access by a technician. It also contains a lightning arrestor, fuse and test circuitry which allows the carrier to remotely test whether a wiring fault lies in the customer premises or in the carrier wiring, without requiring a technician at the premises. The demarcation point has a user accessible RJ-11 jack (a "test jack" or "demarcation jack"), which is connected directly to the telephone network, and a small loop of telephone cord connecting to the jack by a modular connector.

When the loop is disconnected, the on-premises wiring is isolated from the telephone network and the customer may directly connect a telephone to the network via the jack to assist in determining the location of a wiring fault. In most cases, everything from the central office to and including the demarcation point is owned by the carrier and everything past it is owned by the property owner.

As the local loop becomes upgraded, with fiber optic and coaxial cable technologies sometimes replacing the original unshielded twisted pair to the premises, the demarcation point has grown to incorporate the equipment necessary to interface the original premises POTS wiring and equipment to the new communication channel.

Demarcation points on houses built prior to the Bell System divestiture usually do not contain a test jack. They only contained a spark-gap surge protector, a grounding post and mount point to connect a single telephone line. The second wire pair was usually left unconnected and were kept as a spare pair in case the first pair was damaged.

DEMARCs that handle both telephony and IT fiber optic internet lines often do not look like the ones pictured above. In many places several customers share one central DEMARC for a commercial or strip mall setting. Usually a DEMARC will be located indoors if it is serving more than a single customer. This may impede access. Outdoor ones provide easier access, without disturbing other tenants, but call for weatherproofing and punching through a wall for each new addition of wires and service.

Typically indoor DEMARC's will be easily identified by a patch panel of telephone wires on the wall next to a series of boxes with RJ48 jacks for T-1 lines. Each business or individual customer can expect their own separate box for internet access T-1 lines.

Demarcation point extension

A demarcation point extension, or demarc extension is the transmission path originating from the interface of the access provider's side of a demarcation point within a premises and ending at the termination point prior to the interface of the edge Customer Premises Equipment (CPE). This may include in-segment equipment, media converters and patch cords as required to complete the circuit's transmission path to the edge CPE. A demarc extension is more correctly termed "Service Interface Extension", and may also be referred to as inside wiring, extended demarc, circuit extension, CPE cabling, riser cabling or DMARC extension.

A demarc extension became an important factor to consider in a building's telecommunications infrastructure after the 1984 deregulation of AT&T as well as the supplemental FCC rulings of 1991, 1996 and 1997. Preceding these rulings, the Bell System Companies held a monopoly and did not allow an interconnection with third party equipment. The incumbent local exchange carriers (ILEC) and other local access providers are now mandated by federal law to provide a point where the operational control or ownership changes. This separation between the local access provider and the end user/subscriber is called the demarcation point within a facility (typically a short distance from the minimum point of entry). This then becomes the responsibility of the end user to extend their service to the CPE location within a facility to provide connectivity for service, requiring a service interface extension, or otherwise called a demarc extension.

United Kingdom

In the United Kingdom, the demarcation point occurs on the LJU master socket, whose wiring is partly owned by the customer, partly owned by the phone company. Other secondary sockets are the customer's property. Newer NTE-5 master phone sockets have a removable front panel: the front panel and its wiring is the customer's, while the rear wiring is Openreach's.

The removable panel allows separation of these two parts and independent maintenance, and access to a test socket to determine whether line faults are in the customer's wiring or Openreach's (formerly BT's) external network.

title: Demarcation point


text:
David Boyd

David Boyd may refer to:

Entertainment

 * David Boyd (artist) (1924–2011), Australian artist
 * David Boyd (author) (born 1951), Canadian children's author
 * David Boyd (cinematographer), American cinematographer
 * David Boyd (singer) (born 1988), Danish-American lead singer of the band New Politics
 * David James Boyd (born 1975), American composer and actor

Sports

 * Dave Boyd (1927–2017), Australian rules footballer
 * David Boyd (cricketer) (born 1955), Australian cricketer
 * David Boyd (footballer) (1870–1909), Scottish cricketer
 * David Boyd (rugby league) (born 1966), Australian rugby league player

Other

 * David Boyd (murderer), British convicted murderer
 * David Boyd (surgeon) (born 1937), American surgeon
 * David French Boyd (1834–1899), Confederate army officer
 * David R. Boyd, Canadian UN Special Rapporteur on Human Rights and the Environment
 * David Ross Boyd (1853–1936), American academic
 * David William Boyd (born 1941), Canadian mathematician

title: David Boyd


text:
Fort Donelson

Fort Donelson was a fortress built early in 1862 by the Confederacy during the American Civil War to control the Cumberland River, which led to the heart of Tennessee, and thereby the Confederacy. The fort was named after Confederate general Daniel S. Donelson.

The Union Army of the Tennessee, commanded by Brigadier General Ulysses S. Grant, who later became president, captured the fort in February 1862 from the Confederate Army in the Battle of Fort Donelson. This was a great strategic victory for the Union forces, and part of Grant's campaign to gain control of the Mississippi River. Union forces occupied the fort (and much of Tennessee) for the remainder of the war. A small detachment of Confederate troops made one unsuccessful attempt in 1863 to regain it.

History
Bushrod Johnson of the Confederate Corps of Engineers had approved the build site and supervised construction completed in early 1862. The site commanded a bend on the west side of the Cumberland River, It was planned to support Fort Henry, which is located on a bend in the Tennessee River about 10 miles to the west. To the north flows Hickman River, a backwater channel that was impassable except by boat or bridge, and to the east a small tributary named Indian Creek enters the Cumberland. The fort, which was intended to house troops and protect the water batteries from sorties, had a few acres of log huts.

Like Fort Henry, which fell to Union troops on February 6, Fort Donelson would not be able to defeat a large-scale assault, but officers wanted to be able hold the position as long as possible. Engineers began improving defensive positions by digging rifle pits along a ridgeline and breastworks were built in "a three-mile arc which inclosed [sic] the bluff on the north, and the county seat hamlet of Dover on the south, the main supply base." Cannons, including a 128-pounder and two 32-pounders, were placed atop the hundred-foot bluff within the arc. Construction was started by a large force of workers brought from the nearby Cumberland Iron Works.

Confederate commanders
 * Bushrod Johnson (Feb 9, 1862)
 * Gideon J. Pillow (Feb 10–13, 1862)
 * John B. Floyd (Feb 14–16, 1862)
 * Simon B. Buckner, Sr. (Feb 16, 1862)
 * Major Rice E. Graves, Jr., Artillery Commander

Fort Donelson was garrisoned by the Confederate troops until 1862. The fort was captured by Union General Ulysses S. Grant and his army during a winter offensive to control of the Mississippi River. Grant believed that such control would enable him to divide the Confederacy in two. (see Battle of Fort Donelson)

On August 25, 1863, a Confederate force attacked the fort and demanded surrender by Union troops. Their attack was unsuccessful and was repulsed by the Union garrison.

Union attack
Fort Donelson was attacked by General U.S Grant and Flag Officer Andrew Foote, who surrounded the fort and captured it after a short siege. On February 6, Grant was ordered by General Henry Halleck to assault Fort Donelson immediately and capture it by February 8. Grant made reconnaissance, observed the natural obstacles and Confederate improvements, and knew the fort would not be taken by the 8th. He organized and had Brigadier Generals John A. McClernand, Charles F. Smith, and Lew Wallace prepare for a land assault while Flag Officer Foote moved his gunboats to assault from the river. After minor skirmishes with Confederate cavalry en route, the assault on Fort Donelson began on February 12. On February 14, a naval battle took place, in which Union ships suffered serious damage. After attempting in vain to escape their tenuous position on February 15 via roads to Nashville, the Confederates capitulated, surrendering Fort Donelson to the Union on February 16.

Fort Donelson under Union control
The Union was ecstatic when the news of Fort Donelson's surrender reached the capital and cities. Union forces now controlled one of the largest forts in the western theater. The war had been going badly for the Union in Virginia, but the captures of Fort Henry and Fort Donelson were promising victories.

After the front line shifted away from Fort Donelson, it became of little strategic importance, but continued to hold a garrison of Union troops. Later, the fort was attacked by a Confederate force of 450 infantrymen, 335 cavalrymen, and two field guns. The Union garrison consisted of four companies (404 men) of the 71st Ohio Regiment. After suffering 30 casualties, the Confederates retreated. They were pursued by the Fifth Iowa Cavalry, but to no avail.

Union commanders
 * Ulysses S. Grant (Feb 1862)
 * Abner Harding (Sept 1862–1863)
 * William W. Lowe (Feb 1863)

After the war
The Fort Donelson National Battlefield was created in 1928, and the park was listed on the National Register of Historic Places on October 15, 1966. It was redesignated as a national battlefield on August 16, 1985. Fort Heiman was later incorporated into the park.

title: Fort Donelson


text:
Talk:Fort Donelson

Wiki Education Foundation-supported course assignment
This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Student editor(s): T-slice16.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 21:42, 16 January 2022 (UTC)

Structure
Usually we put information on the Fort under this title and information on the battle under Battle of Fort Donelson. It helps the consistency. Rmhermen 19:39 20 Jun 2003 (UTC)

title: Talk:Fort Donelson


text:
Talk:Nicholas Ridley (martyr)

GA?
It needs quite a bit of work to get to GA. I have structured the article to some degree and suggest you look at other GA bishops, such as Dunstan to get an idea on how to procede. the first thing that needs to be done is we need to provide in-line citations (see WP:RS) for what we have already. Material to add and cite should then describe his work in the reign of Edward VI. This would be a good a spot to discuss his theology. The period between 1529 and 1540 also is vaccant. Just some ideas. -- Secisek (talk) 07:26, 14 March 2009 (UTC)

 * I ended up working on this all night (not my plan) and now it is not so far from GA. Add and cite whatever you can.-- Secisek (talk) 11:04, 14 March 2009 (UTC)

 * Good job, it looks much improved after the all-nighter. I managed to get a copy of the biography of Ridley by Jasper Ridley. So I might try tackling this after some other projects. --RelHistBuff (talk) 20:26, 14 March 2009 (UTC)

You need to go after Richard Hooker next. That said, any help would be most welcome. The cites here are very sloppy and - clearly - based off your work at Cranmer. -- Secisek (talk) 07:18, 15 March 2009 (UTC)

 * Given how big the back log is over there, I am going to nominate this for GA now and get it in a position to pass. I never gave this article much thought until someone asked me to offer a few improvement suggestions. Due to his prominent place in Foxe, there is a common belief that he was very important to the formation of the Church of England - a stand which is then often dismissed by scholars as hyperbole. I agreed with the latter assesment. After doing some work here, I see the bishop WAS a very interesting fellow. The truth seems to be, he was more than a mere martyr, but perhaps something less than a true leader of the English Reformation on the level of Cranmer or Hooker. I look forward to seeing where the FA editors take this someday. -- Secisek (talk)

Weasel wording
Phrasing: [This is quoted in Acts and Monuments by John Foxe, who put the story of their deaths to effective use.] It is not, however, in the first edition of the book shows some unfortunate pro-catholic bias - the first edition od Foxe's is generally much worse substantiated by documents than the the following ones, which should be mentioned - the current wording somewhat implies the opposite.--87.249.145.69 (talk) 16:23, 11 September 2014 (UTC)

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Transubstantiation
I don't understand how the wikipedia entry for Nicholas Ridley makes no mention of this.

title: Talk:Nicholas Ridley (martyr)