5,416 research outputs found
Dissociation and relative stability of sodium fluotitanate
Titanium is urgently needed in the armament industry especially as a substitute for 18-8 stainless steel. There would be an almost inexhaustible supply of ores of titanium if high-purity titanium metal could be produced economically in large quantities. The use of titanium would permit much of the scarce nickel and chromium to be made available for other important uses.
It has been found by H. C. Kawecki and E. J. Bielecki that high-purity Na2TiF6, K2TiF6, and (NH4)2TiF6 can be produced from iron-bearing titaniferous raw material, ilmenite ores, or a slag concentrate.
The study of the rate of evaporation and reduction of Na2TiF6 was undertaken as a part of a general investigation on treating the titanium compounds recovered from iron-bearing titaniferous raw materials.
The reduction of metal oxides in vacuum has been studied by Dr. Kroll and Dr. Schlechten. They have been able to reduce many metals from their oxides under reduced pressures using carbon as a reducing agent. The volatility and stability of metallic sulphides has been studied in vacuum by Dr. Hsiao and Dr. Schlechten. They have been able to classify a large number of sulfides according to their relative volatility and stability.
A similar method of approach was employed in this research as described in the previously mentioned references. The first step was to make the compound (Na2TiF6) in the laboratory, the next step was to study this compound by the Langmuir Method, and finally an attempt was made to decompose the Na2TiF6 with AlF3 --Introduction, pages 1-2
Transcervical Versus Laparoscopic Insemination in Nulliparous and Multiparous Ewes After Estradiol Cypionate Treatment
The only practical method for artificially breeding ewes with frozen semen is laparoscopic insemination into the lumen of the uterine horn. Like all surgical procedures, however, laparoscopic artificial inseminatiom has limitations. The procedure requires surgical skill and costly equipment. Repeated passage of the laparoscope through the abdominal wall causes adhesions. Depositing frozen/thawed semen at the os cervix results in low conception rates. The inability to pass an insemination pipette through the cervix has prevented artificial insemination in sheep from becoming a standard breeding method as in the cattle industry. This study compared laparoscopic and transcervical methods of insemination in nulliparous ewes and transcervical insemination in multiparous ewes after estradiol cypionate treatment.
Forty nulliparous commercial-cross Rambouillet ewes were treated with pessaries containing fluorogesterone acetate to synchronize estrus. After 14 days, pessaries were removed and ewes were injected IM with 400 IU of pregnant mare serum gonadotropin (PMSG). Ewes were randomly divided into laparoscopic and transcervical treatment groups, 14 and 26 respectively. Ewes were inseminated with thawed semen (75x106 motile spermatozoa). Pregnancy rate with laparoscopic insemination was 85% (confirmed at 55 days with real-time ultrasound) .. With the transcervical method, the speculum could only be inserted into the vagina of five ewes and the insemination pipette could only be passed through the cervix in two ewes. The combined pregnancy rate for deep cervical and transcervical insemination was 40% at 55 days.
Forty multiparous commercial-cross Rambouillet ewes were synchronized as previously described. Ewes were randomly separated into a control and estradiol cypionate treatment group of 20 animals each. Within each group 10 ewes were inseminated with frozen/thawed Suffolk semen and 1 Owith Rambouillet semen. Ten ewes within each sire genotype were treated with 1 mg IM of estradiol cypionate 16 hours prior to insemination. Treated ewes were inseminated into the uterine body 90% of the time and non-treated ewes 95%. There was no significant difference in cervical passage between these groups.
Pregnancy rates for transcervical artificial insemination in the Suffolk genotype were 0.05% and 40% in the Rambouillet (pregnancy confirmed at 55 days by real-time ultrasound). Lambing rates for the Suffolk and Rambouillet groups were zero and 0.05%, respectively
A modified Fresnel scattering model for the parameterization of Fresnel returns, part 2.3A
A modified Fresnel scatter model is presented and the revised model is compared with observations from the Poker Flat, Alaska, radar, the SOUSY radar and the Jimcamarca radar. The modifications to the original model have been made to better account for the pulse width dependence and height dependence of backscattered power observed at vertical incidence at lower VHF. Vertical profiles of backscattered power calculated using the revised model and routine radiosonde data show good agreement with observed backscattered power profiles. Relative comparisons of backscattered power using climatological data for the model agree fairly well with observed backscattered power profiles from Poker Flat, Jicamarca, and SOUSY
The proposed flatland radar
A flexible very high frequency (VHF) stratosphere-troposphere (ST) radar configured for meteorological research is to be constructed near Urbana, Illinois. Measurement of small vertical velocities associated with synoptic-scale meteorology can be performed. A large Doppler microwave radar (CHILL) is located a few km from the site of the proposed ST radar. Since the microwave radar can measure the location and velocity of hydrometeors and the VHF ST radar can measure clear (or cloudy) air velocities, simultaneous observations by these two radars of stratiform or convective weather systems would provide valuable meteorological information
“We’re Never Off Duty”: Empire and the Economies of Race and Gender in the U.S. Military Camptowns of Korea
This article focuses on the relationships between the U.S. military, race, masculinity, and power in South Korea. I argue that notions of empire are played out in off-base interactions among U.S. soldiers themselves, but also between U.S. soldiers and non-U.S. military others, particularly in the post-9/11 “war on terror” era. In these strategic interplays, soldiers often carry stereotypes held in the United States, but also reinforced by their identities and training as U.S. soldiers. Globalization trends and international relations also influence modes of communication and relations within this hierarchically ranked system and structure. This article discusses how power, gender, race, and racisms play out in the camptowns of South Korea by using an ethnographic lens to link the human face with empire
Hydrocarbon-fuel/combustion-chamber-liner materials compatibility
Results of material compatibility experiments using hydrocarbon fuels in contact with copper-based combustion chamber liner materials are presented. Mil-Spec RP-1, n- dodecane, propane, and methane fuels were tested in contact with OFHC, NASA-Z, and ZrCu coppers. Two distinct test methods were employed. Static tests, in which copper coupons were exposed to fuel for long durations at constant temperature and pressure, provided compatibility data in a precisely controlled environment. Dynamic tests, using the Aerojet Carbothermal Test Facility, provided fuel and copper compatibility data under realistic booster engine service conditions. Tests were conducted using very pure grades of each fuel and fuels to which a contaminant, e.g., ethylene or methyl mercaptan, was added to define the role played by fuel impurities. Conclusions are reached as to degradation mechanisms and effects, methods for the elimination of these mechanisms, selection of copper alloy combustion chamber liners, and hydrocarbon fuel purchase specifications
Orbit transfer rocket engine integrated control and health monitoring system technology readiness assessment
The objectives of this task were to: (1) estimate the technology readiness of an integrated control and health monitoring (ICHM) system for the Aerojet 7500 lbF Orbit Transfer Vehicle engine preliminary design assuming space based operations; and (2) estimate the remaining cost to advance this technology to a NASA defined 'readiness level 6' by 1996 wherein the technology has been demonstrated with a system validation model in a simulated environment. The work was accomplished through the conduct of four subtasks. In subtask 1 the minimally required functions for the control and monitoring system was specified. The elements required to perform these functions were specified in Subtask 2. In Subtask 3, the technology readiness level of each element was assessed. Finally, in Subtask 4, the development cost and schedule requirements were estimated for bringing each element to 'readiness level 6'
James L. Goodloe to Mrs. V. G. Armistead (15 March 1911)
Concerns affection for Jeremiah and his other departed friendshttps://egrove.olemiss.edu/ciwar_corresp/1479/thumbnail.jp
James L. Goodloe to Mrs. V. G. Armistead (26 June 1913)
Concerns affection for Jeremiah and references the article written by Holthttps://egrove.olemiss.edu/ciwar_corresp/1481/thumbnail.jp
James L. Goodloe to Mrs. V. G. Armistead (2 July 1913)
Thanks Mrs. Armistead for the photograph of Jeremiah and discusses attempts to publish an article on Gage in the Commercial Appealhttps://egrove.olemiss.edu/ciwar_corresp/1482/thumbnail.jp
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