Econstudentlog

Wikipedia articles of interest

i. Stirling engine.

“A Stirling engine is a heat engine operating by cyclic compression and expansion of air or other gas, the working fluid, at different temperature levels such that there is a net conversion of heat energy to mechanical work.[1][2] Or more specifically, a closed-cycle regenerative heat engine with a permanently gaseous working fluid, where closed-cycle is defined as a thermodynamic system in which the working fluid is permanently contained within the system, and regenerative describes the use of a specific type of internal heat exchanger and thermal store, known as the regenerator. It is the inclusion of a regenerator that differentiates the Stirling engine from other closed cycle hot air engines.

Originally conceived in 1816 as an industrial prime mover to rival the steam engine, its practical use was largely confined to low-power domestic applications for over a century.[3]

The Stirling engine is noted for its high efficiency compared to steam engines,[4] quiet operation, and the ease with which it can use almost any heat source. This compatibility with alternative and renewable energy sources has become increasingly significant as the price of conventional fuels rises, and also in light of concerns such as peak oil and climate change. This engine is currently exciting interest as the core component of micro combined heat and power (CHP) units, in which it is more efficient and safer than a comparable steam engine.[5][6] […]

In contrast to internal combustion engines, Stirling engines have the potential to use renewable heat sources more easily, to be quieter, and to be more reliable with lower maintenance. They are preferred for applications that value these unique advantages, particularly if the cost per unit energy generated is more important than the capital cost per unit power. On this basis, Stirling engines are cost competitive up to about 100 kW.[56]

Compared to an internal combustion engine of the same power rating, Stirling engines currently have a higher capital cost and are usually larger and heavier. However, they are more efficient than most internal combustion engines.[57] Their lower maintenance requirements make the overall energy cost comparable. The thermal efficiency is also comparable (for small engines), ranging from 15% to 30%.[56] For applications such as micro-CHP, a Stirling engine is often preferable to an internal combustion engine. Other applications include water pumping, astronautics, and electrical generation from plentiful energy sources that are incompatible with the internal combustion engine, such as solar energy, and biomass such as agricultural waste and other waste such as domestic refuse. Stirlings are also used as a marine engine in Swedish Gotland-class submarines.[58] However, Stirling engines are generally not price-competitive as an automobile engine, due to high cost per unit power, low power density and high material costs.”

Sixty Symbols at one point made a neat little video about these engines – you can watch the video here.

ii. Doolittle Raid.

USS_Hornet_flight_deck_April_1942

“The Doolittle Raid, also known as the Tokyo Raid, on 18 April 1942, was an air raid by the United States on the Japanese capital Tokyo and other places on Honshu island during World War II, the first air raid to strike the Japanese Home Islands. It demonstrated that Japan itself was vulnerable to American air attack, was retaliation for the Japanese attack on Pearl Harbor on 7 December 1941, provided an important boost to U.S. morale, and damaged Japanese morale. The raid was planned and led by Lieutenant Colonel James “Jimmy” Doolittle, U.S. Army Air Forces.

Sixteen U.S. Army Air Forces B-25B Mitchell medium bombers were launched without fighter escort from the U.S. Navy‘s aircraft carrier USS Hornet deep in the Western Pacific Ocean, each with a crew of five men. The plan called for them to bomb military targets in Japan, and to continue westward to land in China—landing a medium bomber on the Hornet was impossible. Fifteen of the aircraft reached China, and the other one landed in the Soviet Union. All but three of the crew survived, but all the aircraft were lost. […]

The raid caused negligible material damage to Japan, only hitting non-military targets or missing completely […] but it succeeded in its goal of helping American morale and casting doubt in Japan on the ability of its military leaders. It also caused Japan to withdraw its powerful aircraft carrier force from the Indian Ocean to defend their Home Islands, and the raid contributed to Admiral Isoroku Yamamoto‘s decision to attack Midway—an attack that turned into a decisive strategic defeat of the Imperial Japanese Navy (IJN) by the U.S. Navy near Midway Island in the Central Pacific. […]

Immediately following the raid, Doolittle told his crew that he believed the loss of all 16 aircraft, coupled with the relatively minor damage to targets, had rendered the attack a failure, and that he expected a court-martial upon his return to the United States. Instead, the raid bolstered American morale to such an extent that Doolittle was awarded the Medal of Honor by President Roosevelt, and was promoted two grades to brigadier general, skipping the rank of colonel. […]

Following the Doolittle Raid, most of the B-25 crews who had reached China eventually achieved safety with the help of Chinese civilians and soldiers. Of the 80 airmen who participated in the raid, 69 escaped capture or death. When the Chinese helped the Americans escape, the grateful Americans in turn gave them whatever they had on hand. The people who helped them, however, paid dearly for sheltering the Americans.”

The Japanese were pretty pissed afterwards:

“The Japanese military began the Zhejiang-Jiangxi Campaign to intimidate the Chinese from helping the American airmen. All airfields in a range of some 20,000 square miles (50,000 km2) in the areas where the Raiders had landed were torn up.[28] Germ warfare was used and atrocities committed, and those found with American items were shot. The Japanese killed an estimated 250,000 Chinese civilians during their search for Doolittle’s men.[29][30] […] On 28 August 1942, pilot Hallmark, pilot Farrow and gunner Spatz faced a war crimes trial by the Japanese for allegedly strafing Japanese civilians. At 16:30 on 15 October 1942 they were taken by truck to Public Cemetery Number 1, and executed by firing squad. The other captured airmen remained in military confinement on a starvation diet, their health rapidly deteriorating. In April 1943, they were moved to Nanking, where Meder died on 1 December 1943. The remaining men, Nielsen, Hite, Barr and DeShazer, eventually began receiving slightly better treatment and were given a copy of the Bible and a few other books. They were freed by American troops in August 1945.”

iii. Missouri Executive Order 44.

Missouri Executive Order 44, also known as the Extermination Order in Latter Day Saint history,[1][2] was an executive order issued on October 27, 1838 by the governor of Missouri, Lilburn Boggs. It was issued in the aftermath of the Battle of Crooked River, a clash between Mormons and a unit of the Missouri State Guard in northern Ray County, Missouri, during the Mormon War of 1838. Claiming that the Mormons had committed “open and avowed defiance of the laws”, and had “made war upon the people of this State,” Boggs directed that “the Mormons must be treated as enemies, and must be exterminated or driven from the State if necessary for the public peace—their outrages are beyond all description”.[2]

While Executive Order 44 is often referred to as the “Mormon Extermination Order” due to the phrasing used by Boggs, no one is known to have been killed by the militia or anyone else specifically because of it. There were, however, other associated deaths: the militia and other state authorities used Boggs’ missive as a pretext to expel the Mormons from their lands in the state, and force them to migrate to Illinois. This forced expulsion in difficult, wintry conditions posed a substantial threat to the health and safety of the affected Mormons, and an unknown number died from hardship and exposure. Furthermore, a group of men and boys were killed by Livingston County militia in the Haun’s Mill massacre three days after the order was issued; however, there is no evidence that the militiamen had any knowledge of it, nor did they ever use the order to justify their actions.

Mormons did not begin to return to Missouri until 25 years later, when they found a more welcoming environment and were able to establish homes there once more. […] Boggs’ extermination order, long unenforced and forgotten by nearly everyone outside the Latter Day Saint community, was formally rescinded by Governor Christopher S. Bond on June 25, 1976, 137 years after being signed.”

iv. Ug99. This is probably the kind of thing you’d prefer most people never to learn anything about. At least I’d say that if something like this ever becomes a household name, this is very bad news:

Ug99 is a lineage of wheat stem rust (Puccinia graminis f. sp. tritici), which is present in wheat fields in several countries in Africa and the Middle East and is predicted to spread rapidly through these regions and possibly further afield, potentially causing a wheat production disaster that would affect food security worldwide.[1] It can cause up to 100% crop losses and is virulent against many resistance genes which have previously protected wheat against stem rust.

Although Ug99-resistant varieties of wheat do exist, a screen of 200 000 wheat varieties used in 22 African and Asian countries found that only 5-10% of the area of wheat grown in these countries consisted of varieties with adequate resistance.[1]

v. Egyptian temples (featured).

800px-SFEC_AEH_-ThebesNecropolis-2010-RamsesIII045

Some quotes from the article:

“Each temple had a principal deity, and most were dedicated to other gods as well.[9] However, not all deities had temples dedicated to them. Many demons and household gods were involved primarily in magical or private religious practice, with little or no presence in temple ceremonies. There were also other gods who had significant roles in the cosmos but, for uncertain reasons, were not honored with temples of their own.[10] Of those gods who did have temples of their own, many were venerated mainly in certain areas of Egypt, though many gods with a strong local tie were also important across the nation.[11] Even deities whose worship spanned the country were strongly associated with the cities where their chief temples were located. In Egyptian creation myths, the first temple originated as a shelter for a god—which god it was varied according to the city—that stood on the mound of land where the process of creation began. Each temple in Egypt, therefore, was equated with this original temple and with the site of creation itself.[12] As the primordial home of the god and the mythological location of the city’s founding, the temple was seen as the hub of the region, from which the city’s patron god ruled over it.[13]

Pharaohs also built temples where offerings were made to sustain their spirits in the afterlife, often linked with or located near their tombs. These temples are traditionally called “mortuary temples” and regarded as essentially different from divine temples. However, in recent years some Egyptologists, such as Gerhard Haeny, have argued that there is no clear division between the two.” […]

“The earliest known primitive shrines appeared in Egypt by the late Predynastic Period, in the late fourth millennium BC. […] Temple-building continued down until the 4th century AD.[63] However, with the rise of the Christian Roman Emperors temples lost their traditional state funding, had their treasures melted down, and the proceeds redirected towards the building of churches.[64] In AD 391 all pagan cults were banned by Theodosius I and in this same year the Serapeum of Alexandria was destroyed by Christians.[65] Attacks on pagans and temples were widespread throughout Egypt.[66] A few temples, such as Luxor, were converted into churches, while many others went completely disused.[67] In AD 550, Philae, the last functioning temple in Egypt, was closed.[68]

“Some estimate that by the New Kingdom period, temples owned about 33% of the arable land.[44]

“A temple needed many people to perform its rituals and support duties. Priests performed the temple’s essential ritual functions, but in Egyptian religious ideology they were far less important than the king. As temple decoration illustrates, all ceremonies were, in theory, acts by the king, and priests merely stood in his place. The priests were therefore subject to the king’s authority, and he had the right to appoint anyone he wished to the priesthood. In fact, in the Old and Middle Kingdoms most priests were government officials who left their secular duties for part of the year to serve the temple in shifts.[125] Once the priesthood became more professional, the king seems to have used his power over appointments mainly for the highest-ranking positions, usually to reward a favorite official with a job or to intervene for political reasons in the affairs of an important cult. […] Besides its priests, a large temple employed singers, musicians, and dancers to perform during rituals, plus the farmers, bakers, artisans, builders, and administrators who supplied and managed its practical needs.[133] A major cult […] could have well over 150 full or part-time priests,[134] with tens of thousands of non-priestly employees working on its lands across the country.[135] These numbers contrast with mid-sized temples, which may have had 10 to 25 priests, and with the smallest provincial temples, which might have only one.[136]” […]

“After their original religious activities ceased, Egyptian temples suffered slow decay. Many were defaced or dismantled by Christians trying to erase the remnants of paganism. Over time locals carried off their stones to use as material for new buildings.[67] What humans left intact was still subject to natural weathering. Temples in desert areas could be covered by drifts of sand, while those near the Nile, particularly in Lower Egypt, were often completely buried under layers of river-borne silt. Thus, some major temple sites like Memphis and Heliopolis were reduced to ruin, while many temples far from the Nile and centers of population remained mostly intact. […] Nineteenth-century Egyptologists studied the temples intensively, but their emphasis was on collection of artifacts to send to their own countries, and their slipshod excavation methods often did further harm.[174] Slowly, however, the antique-hunting attitude toward Egyptian monuments gave way to careful study and preservation efforts. […] Today there are dozens of sites with substantial temple remains,[177] although many more once existed, and none of the major temples in Lower or Middle Egypt are well preserved.[178] […] Archaeological work continues as well, as many temple remains still lie buried and many extant temples are not yet fully studied.”

Glycolysis.

(Actually I’m not sure this one is really that interesting, but it was one of the articles I was browsing a couple of days ago while reading McPhee et al. When I had had a brief look at this article, I concluded that I really didn’t need to understand the specific line of reasoning in the book that had made me look up that stuff..).

November 6, 2013 - Posted by | biology, history, wikipedia

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