The bristlenose pleco (Ancistrus cirrhosus) is a species of armored catfish in the Loricariidae family that breathes air facultatively when the aquatic environment becomes hypoxic. The bristlenose pleco uses its highly vascularized stomach as an air breathing organ. The two main goals of this developmental study were to determine the size of onset of air breathing and to determine the frequency of air breathing behavior in bristlenose plecos from juveniles to adults. Developing juveniles reach functional maturity within four to six months of hatching and grow to an adult size of eight to ten cm in length. To examine the developmental timing for the onset of air breathing, we tested different sized juveniles beginning at one cm up until 8 cm in length. The developmental timing for the onset of air breathing was measured by exposing each fish to a slowly decreasing aquatic oxygen content from 100% air saturation down to 8% air saturation. Fish were first able to breathe air at just over 2 cm and 1 gram in mass. There was a weak negative correlation between fish length and % air saturation at which air breathing began. When exposed to 15% air saturation, frequency of air breathing was negatively correlated with fish length. Armored catfish are becoming an invasive species in the southern US, outcompeting local fauna potentially because of this adaptation. This research provides important insight into the development of the air breathing adaptation that may allow these fish to outcompete the others.

Thesis (M.A.)--East Carolina University, 2009. / Presented to the faculty of the Department of History. Advisor: Lawrence Babits. Includes bibliographical references (leaves [125]-136). Also available via the World Wide Web. Adobe reader required.

This study described the operation and organization of the United States Army's Second Armored Division's Public Affairs Office, with emphasis on the differences between garrison and field operations. The study found that the function of the division, public affairs office is to keep both the internal and external public(s) of the division informed concerning the activities of the division. The office is organized into three branches: command information, public information, and administration. During garrison operations, all members of the office operate from a building at Fort Hood, Texas. During field operations, office personnel organize into teams in order to provide information to all public(s), internal and external.

This thesis, through examination of the battles of Kadesh (1288 B.C.), Alam Halfa (1942), and the Arab-Israeli War (1967), attempts to determine the degree of similarity between tactical employment of the ancient chariot and modern armored vehicles. Sources include official analysis and records of participants and observers. This thesis proves that tactical employment of chariots and modern armored vehicles is clearly similar. Chariots were used to support infantry in the three conflicts examined. Also proved is that chariots were used almost identically with armored vehicles in exploiting a breakthrough, serving as reaction forces, making a reconnaissance, conducting retrograde operations, and holding or blocking enemy forces.

Le but de cette thèse est d’analyser l’emploi des blindés dans globalité et jusqu’aux plus petits échelons (pelotons, équipages) c’est-à-dire à hauteur d’hommes (slogan devenu à la mode depuis). En effet beaucoup d’écrits et d’études précédents restent souvent au niveau tactique voire stratégique. Il s’agit également d’étudier les éventuelles différences entre la théorie doctrinale et son application sur le terrain, voir si l’emploi des blindés variait en fonction des acteurs et si oui pourquoi. Cette étude se veut globale, elle prend en compte, les hommes (donc leur formation, leur origine, leur passé), la doctrine et le matériel car l’emploi au combat est la réunion de tous ces facteurs. Les recherches montrent que les trois GU blindées françaises n’étaient pas employées de la même façon, la raison principale résidant dans les conceptions d’emploi des chefs. Les unités blindées françaises étaient composées d’hommes au passé et au parcours différents. Des Gaullistes historiques au jeune engagé d’aout 1944 en passant par les rappelés de l’armée d’Afrique. Tous se retrouvèrent dans les tourelles avec un même but libérer le pays. Elles-mêmes avaient des origines diverses. Certaines n’avaient cessé de combattre, d’autres étaient restées en Afrique du nord ou en Afrique occidentale jusqu’au débarquement allié de novembre 1942. Mais toutes montrèrent un haut niveau de maîtrise tactique et de professionnalisme Leur équipement et leur organisation étaient homogènes car d’origine américain. Leur concept d’emploi était celui dicté par les FM qu’elles adaptèrent à leur main pour combattre à la Française et parfois marquer leur différence par rapport aux alliés. Une fois engagées, elles tinrent toute leur place aux côtés des unités alliés, prouvant leur valeur et marquant ainsi la renaissance de l’armée française. Cette unicité d’organisation, de doctrine et d’équipement masque cependant des différences dans l’emploi. Elles furent tributaires des grandes unités auxquelles elles étaient rattachées et de leur chef. L’emploi des unités blindées dépendait en grande partie des hommes. Des chefs d’abord dont tous n’avaient pas les mêmes conceptions d’emploi des unités blindées ce qui se traduisit par des frustrations et des conflits en particulier entre les généraux Leclerc et de Lattre. Mais également des équipages qui firent preuve d’un état d’esprit remarquable mais particulier et de beaucoup d’abnégation. / The aim of this thesis is to analyze the use of armored vehicles globally and up to the smallest levels (platoons, crews), that is to say at the level of men (slogan that has become fashionable ever since). Indeed, many previous writings and studies often remain at the tactical or strategic level. It is also a question of studying the possible differences between the doctrinal theory and its application in the field, to see if the use of armored vehicles varied according to the actors and if so why. This study is intended to be comprehensive, it takes into account, men (thus their training, their origin, their past), doctrine and equipment because employment in combat is the meeting of all these factors. Research shows that the three French armored GUs were not employed in the same way, the main reason residing in the chiefs' conceptions of employment. French armored units were made up of men with different backgrounds and backgrounds. From the historical Gaullists to the young worker of August 1944, passing by the recalled African army. All found themselves in the turrets with the same goal to liberate the country. They themselves had various origins. Some had continued to fight, others had remained in North Africa or West Africa until the Allied landings of November 1942. But all showed a high level of tactical mastery and professionalism. Their equipment and organization were homogeneous because of American origin. Their concept of employment was that dictated by the FM that they adapted to their hand to fight the French and sometimes mark their difference compared to the allies. Once engaged, they held their place alongside the allied units, proving their value and thus marking the rebirth of the French army. This uniqueness of organization, doctrine and equipment, however, masks differences in employment. They were tributaries of the great units to which they were attached and of their leader. The use of armored units depended largely on men. Chiefs first, all of whom did not have the same conceptions of the use of armored units, which resulted in frustrations and conflicts in particular between Generals Leclerc and de Lattre. But also crews who showed a remarkable state of mind but particular and a lot of self-sacrifice.

In this work, the development of theoretically-dense, clean grain boundary, high hardness solid-state sintered silicon carbide (SiC) armor was pursued. Boron carbide and graphite (added as phenolic resin to ensure the carbon is finely dispersed throughout the microstructure) were used as sintering aids. SiC batches between 0.25-4.00 wt.% carbon were mixed and spray dried. Cylindrical pellets were pressed at 13.7 MPa, cold-isostatically pressed (CIP) at 344 MPa, sintered under varying sintering soaking temperatures and heating rates, and varying post hot-isostatic pressing (HIP) parameters. Carbon additive amounts between 2.0-2.5 wt.% (based on the resin source), a 0.36 wt.% B4C addition, and a 2050°C sintering soak yielded parts with high sintering densities (~95.5-96.5%) and a fine, equiaxed microstructure (d50 = 2.525 µm). A slow ramp rate (10°C/min) prevented any occurrence of abnormal grain growth. Post-HIPing at 1900°C removed the remaining closed porosity to yield a theoretically-dense part (3.175 g/cm3, according to rule of mixtures). These parts exhibited higher density and finer microstructure than a commercially-available sintered SiC from Saint-Gobain (Hexoloy Enhanced, 3.153 g/cm3 and d50 = 4.837 µm). Due to the optimized microstructure, Verco SiC parts exhibited the highest Vickers (2628.30 ± 44.13 kg/mm2) and Knoop (2098.50 ± 24.8 kg/mm2) hardness values of any SiC ceramic, and values equal to those of the "gold standard" hot-pressed boron carbide (PAD-B4C). While the fracture toughness of hot-pressed SiC materials (~4.5 MPa m1/2) are almost double that of Verco SiC (2.4 MPa m1/2), Verco SiC is a better performing ballistic product, implying that the higher hardness of the theoretically-dense, clean-grain boundary, fine-grained SiC is the defining mechanical property for optimization of ballistic behavior.

Submitted in partial fulfillment of the requirements of the Master of Strategic Studies Degree, U.S. Army War College. / Title from title screen (viewed May 22, 2008). Bernard F. Griffard, project adviser. "21 March 2008"--P. [iii]. "ADA479009"--URL. Includes bibliographical references (p. 19-23). Also issued in paper format.

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