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A vacuum cannon (or a ping-pong ball cannon) is commonly used by many physics departments to demonstrate the large forces that result from pressure differentials surrounding an object. In this paper, previous theoretical descriptions for the vacuum cannon are revisited and extended to include the effect of the air-intake aperture size on the projectile speed in the cannon. This extended treatment is mostly analytic although there is a small but necessary numerical aspect to this analysis. Good agreement has been found between theoretical predictions and observations using this new analysis. The principles involved in this theoretical framework are easily accessible to intermediate and advanced undergraduate students, and hence, the vacuum cannon demonstration could easily be transformed into an experiment appropriate for an undergraduate thermal physics course. Students would be expected to perform analytical derivations, write simple computational programs, and perform high-speed video capture and analysis. Thus, students would gain experience with analytical, numerical, and experimental techniques in a single project. [ABSTRACT FROM AUTHOR]

Interior ballistics is of great importance to the study of gun barrels and projectiles. One of its important characteristics is velocity, which determines the firing capability of projectiles. Aiming at the interior ballistic velocity (IBV) of projectiles launched from electromagnetic (EM) rail, this paper has analyzed the differences in the mechanism between the EM rail gun and the traditional cannon. Based on some assumptions, the calculation formula of projectile EM force was gained with the time–frequency analysis method. Then, it built a simulation calculation model of IBV of the projectile. In addition, the use of the positioned data of the magnetic probe (B-dot probe), to obtain the displacement fitting matrix, leads to the establishment of an experimental fitting model of IBV of the projectile. With the plane EM rail launcher in our laboratory as an example, the above-mentioned two models are applied to analyzing the accelerated motion of the projectile in the chamber. The experimental fitting results are compared with the measured data and simulation results of the B-dot probe, which are basically consistent. Thus, it shows that the IBV’s simulation model and the experimental fitting model have high reliability. [ABSTRACT FROM AUTHOR]

This article examines the value of 19th-century archival documents for the archaeological study of the Holy Land. This study focuses on unpublished reports and drawings by Conrad Schick, a Jerusalem resident and a self-educated archaeologist, who worked with the Ordnance Survey of Jerusalem as well as the Palestine Exploration Fund starting from 1865 and reported regularly on his activities to London until his death in 1901. These archival documents include, inter alia, reports on excavations undertaken, plans, cross-sections, and maps. By analysing Schick's largely unpublished correspondence, this study develops methodological guidelines for extracting archaeological information from such archival material. It also directs attention to information furnished by Schick's records on a few less-known sites. [ABSTRACT FROM AUTHOR]

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Analyzes Nicolo Machiavelli's military history writings focusing on his opinion of the cannon. Factors behind Machiavelli's lack of regard for the cannon; Technical question of the Machiavelli's evaluation of the cannon; Insight on Machiavelli's political thought; Technical discourse on the technology of war.

Focuses on the planning for the disposal of nuclear arsenals and warheads despite an absence of arms reduction agreements. Disposal arrangement for uranium-based and plutonium-based weapons; Consideration for the secrecy of information on the design and construction of nuclear weapons; Steps in the implementation of the disposal programs.

Focuses on the legislative deliberations for the Omnibus Defense Authorization Bill for 1985. Amendment limits to the total number of nuclear warheads to be produced and deployed; Appeal for the termination of research and development on nuclear warheads; Arguments for an increase in conventional forces from the North Atlantic Treaty Organization and the U.S. government.

The article presents the author's comments on certain risks and dangers that Hawaii faces for being the U.S. military command and weapons stockpile center of the Pacific. Hawaii faces the local environmental hazards of nuclear weapons as well as the dangerous fallouts of a potential nuclear war. Local hazards of nuclear arsenals include: dangers of weapon accidents, naval pollution of waters in the area due to radioactive liquid waste, and naval reactor accidents, etc.

The article describes the dispersion of United States' tactical and strategic nuclear weapons at home, at sea, in Europe and in Asia. There is an estimated 14,800 nuclear weapons that are kept in the U.S. and about 7,000 weapons are dispersed at sea. In Europe, these weapons include different kinds of surface-to-surface missiles, nuclear artillery shells and nuclear capable fighter-bombers. In Asia, an estimated 1,700 tactical nuclear weapons are maintained on land, reportedly in Korea and the Philippines. INSET: 'Broken Arrows'.

In Focus: Dunphy, CM, Vollmer, SV, Gouhier, TC. (2021) Host–microbial systems as glass cannons: Explaining microbiome stability in corals exposed to extrinsic perturbations. Journal of Animal Ecology, 90, 1044–1057. The importance of symbiotic microbial communities for the functioning of animal hosts is now well‐documented; however, the interactions between host microbiomes and stress are less well‐understood. Dunphy et al. used a common garden experiment to show that host–microbiomes vary in their resilience across different coral species. The authors then used mathematical modelling to provide novel evidence that species with microbiomes that are regulated by host processes are robust to perturbation from stressors, but that robustness comes at a higher cost to the host. Conversely, species with microbiomes that are regulated by microbial processes are generally much more resilient and cheaper to support, but when disrupted by external stressors, the communities break down entirely—these latter species are termed 'glass cannons'. This novel hypothesis has important implications for how host microbiomes function in a rapidly changing world that exposes animal hosts to multiple biotic and abiotic perturbations. [ABSTRACT FROM AUTHOR]

The article provides information on multiple independently targetable reentry vehicle (MIRV) in the U.S. MIRV missiles carry comparatively smaller individual warheads that allows a single launch of missile to strike several targets. The technology of MIRV tends to continue any strategic arms restriction in certain degree of ambiguity that enhances the expected development of strike-force advantage in the future. Its development tolerates SS-9 force capable of throwing 300 MIRV and assumes to intensify the strike force power of 500 MIRVs.

The article discusses the author's perspective on the problems on the detection of atomic test explosions. He points that an agreement which bans nuclear weapons testing would be worthless unless violations could be detected. He also presents the main techniques for detection of nuclear weapons testing which include the detection of acoustic waves, electromagnetic radiation, and radioactivity. He adds that a test-ban agreement which could be checked only by outside monitoring would be successful of its purposes.

The article focuses on the psychological effect of atomic weapons on the American people. According to the government, American people will not panic during atomic attacks for the military were trained to be ready during an attack. However, the author opposed the government's statement and concluded that these people would panic. Moreover, he suggested two factors regarding his conclusion that include the public has exhibited various symptoms including hysteria and the psychological effects of atomic attack is more damaging than physical effects.

The article reports on disarmament control policies regarding atomic energy. According to the author, President Dwight D. Eisenhower's proposal discusses disarmament and cooperation in the development of useful applications of atomic energy. He also discusses "Operation Candor" that focuses on the realities of atomic threat and cooperation with trusted allies wherein it was considered in facing the problem with the development of Soviet Union's hydrogen bomb. Moreover, the disarmament agreement include the maintenance of low level of atomic and other weapons as a preventive measure for possible atomic attacks.

The article discusses the implications of the atomic arms race and cites possible solutions to avert its catastrophic outcome. The strategic use of atomic bombs in warfare invites proliferation of its development in which case a need for an atomic armament control plan is deemed necessary. Several frameworks upon which disarmament control policies should be based is presented one of which is an international agreement which will set limitation on arms production including atomic armaments. The control scheme, however, requires a knowledge in the dynamics of developing an atomic bomb such as plutonium and uranium content or the amount of fissionable material.

This article discusses the activities of Thomas Green, a London gunmaker, and the prejudice against Catholics during his time. Green, who was accused of being a popish recusant, had his firearms seized and faced a warrant for his arrest. The article also mentions the discovery of evidence related to arms seized in Bath during the 1715 Jacobite rising, which were engraved with Green's name. It is suggested that Green, as a gunmaker to the Ordnance, may have produced civilian firearms like the one found in Bath, but this does not make him a participant in the Jacobite rising. Green's petition to the King in 1722 was granted, and the firearms seized from his shop were returned due to a lack of evidence. [Extracted from the article]

In her essay, Angela Pulley Hudson untangles similarities between the dispossession of American Indians of their homelands and the forced dislocation of Mormons from their colonies. It is this dialectic among Talbot's and Hudson's essays that leads me to agree with Rachel St. John's call to "contain Reconstruction." And here, I agree with Hudson, that including Indians and Mormons in Greater Reconstruction "elides both "Mormon complicity in Indian dispossession" and the very nature of settler colonialism.". [Extracted from the article]

"Cherry farmers across Michigan lost a tremendous amount of crop this year. This region of Michigan is known for its fruit production, and the annual cherry harvest never fails to produce the tense bliss of anticipation for the few who live on our mile-long stretch of country road. 18 | JHSM Bulletin Programming Spotlight Making Peace with the Cannon Natalie Ruth Joynton My personal pandemic meltdown came late in the game, months after the first cases of COVID-19 slammed into Michigan in March of 2020. In the accompanying piece Joynton further explores this theme, relating the significant impact on her during the pandemic of a littleknown practice used by cherry farmers. [Extracted from the article]

The Editorial team is grateful to the dedicated reviewers who helped them improve the quality of the articles published from October 2018 until September 2019 within the journal I Rheumatology International i . Soham Al Snih Maria Jose Santos Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. [Extracted from the article]

Firth's were the first of the Sheffield steel makers to enter the field armaments. Their involvement with Colt has been outlined in an article in the journal of the Colt Collectors Association in America and their activities as steelmakers to the small-arms industries has been covered in a previous issue of this Journal. This article gives a brief overview of their involvement as manufacturers in the field of heavy armaments, being the first to make all-steel guns and their evolving role in the use of steel for ordnance, culminating in the displacement of wrought iron by the adoption of steel for ordnance manufacture by the Royal Gun Factory in the 1880s. It also highlights their development of stainless steel in this context. [ABSTRACT FROM AUTHOR]

The characteristics of high-spin, high-load and wide-range of the dual-spin trajectory correction projectile are the main design difficulties of the fixed canard rudder roll control system. Permanent magnet alternating generator within the limited space, which integrates the battery and rudder, as well as its driving and measuring system is designed based on the high-spin and dual-spin characters. Meanwhile, based on the analysis of structure and operating principle, the triple closed-loop roll control system based on parallel processors is proposed, and then the signals under strong interference are processed, completing the roll attitude solution within the whole scope of trajectory. A semi-physical simulation system is built to complete control experiments with the air torque respectively provided by torque motor and wind tunnel. The wireless transmission module has also been equipped to realize real-time display of the measured roll data on the terminal computer. The responding time is less than 0.7 s and the control precision is within ± 5°. It’s proved that the designed generator provides needful torque for control and also power supply for whole electrical circuits, saving both space and cost. It is also demonstrated that the proposed triple closed-loop roll control system has good feasibility, reliability and value in engineering application. [ABSTRACT FROM AUTHOR]

Womanist, mentoring, pedagogy, African American history. [Extracted from the article]

In light of the ongoing debate over tighter firearm regulations, this paper considers the relationship between gun prevalence and suicide. I exploit a reform in Switzerland that reduced the prevalence of military-issued guns in private households. In Switzerland, military service is compulsory for men, and military-issued guns account for nearly half of the total number of firearms available. The results show that the firearm suicide rate decreases by 9% for a reduction in gun prevalence of 1000 guns per 100,000 inhabitants. The elasticity of gun suicides with respect to firearm prevalence is +0.48, but converges towards zero for low levels of gun prevalence. The overall suicide rate is negatively and significantly related to firearm prevalence, which indicates that non-gun methods of suicide are not perfect replacements for firearms. [ABSTRACT FROM AUTHOR]