4,235 Matching Results

Search Results

Advanced search parameters have been applied.

Essentials of Animal Breeding

Description: "This bulletin is written in simple language for the man who breeds farm animals, who wants to learn the rudiments of the science of breeding, and how to apply them in practice. It sets forth some of the known facts regarding the operation of the forces of heredity." -- p. 2. Topics include gestation periods, incubation for birds, fertility, Mendel's law of prepotency, selection, inbreeding, purity and pedigree, and livestock improvement techniques.
Date: 1920
Creator: Rommel, George M. (George McCullough)
Partner: UNT Libraries Government Documents Department

Farm Sheep Raising for Beginners

Description: This bulletin describes methods for raising sheep to farmers who have no experience with sheep. Topics discussed include flock size, breeding, seasonal care and behaviors, and the lambing season.
Date: 1917
Creator: Marshall, F. R. & Millin, R. B.
Partner: UNT Libraries Government Documents Department

A Simple Hog-Breeding Crate

Description: This bulletin gives instructions for making a breeding crate which can be used to assist in the mating of hogs. "There are many types of breeding crates which the farmer may construct. The accompanying illustrations show a crate that can be operated by one man and is easily constructed on the average farm without involving much expense." -- p. 3
Date: 1918
Creator: Zeller, J. H. (John Henry), 1894-
Partner: UNT Libraries Government Documents Department

Corn Cultivation

Description: "It is possible within a few years to double the average production of corn per acre in the United States, and to accomplish it without any increase in work or expense. The lines of improvement that will most easily and quickly double the present production per acre are as follow: (1) Improvement in the quality of seed planted; (2) improvement in the condition of the soil; (3) improvement in methods of cultivation." -- p. 3-4
Date: 1910
Creator: Hartley, C. P.
Partner: UNT Libraries Government Documents Department

Corn Cultivation

Description: Revised edition. "Corn yields per acre in the United States could be doubled within a few years, and this could be accomplished without increase in work or expense.... The lines of improvement that will most easily and quickly double the present production per acre are as follow: (1) Improvement in the quality of seed planted; (2) improvement in the condition of the soil; (3) improvement in methods of cultivation." -- p. 3-4
Date: 1924
Creator: Hartley, C. P.
Partner: UNT Libraries Government Documents Department

Corn Cultivation

Description: Revised edition. "Corn yields per acre in the United States could be doubled within a few years, and this could be accomplished without increase in work or expense.... The lines of improvement that will most easily and quickly double the present production per acre are as follow: (1) Improvement in the quality of seed planted; (2) improvement in the condition of the soil; (3) improvement in methods of cultivation." -- p. 3-4
Date: 1926
Creator: Hartley, C. P.
Partner: UNT Libraries Government Documents Department

Ceramic breeder materials : status and needs.

Description: The tritium breeding blanket is one of the most important components of a fusion reactor because it directly involves both energy extraction and tritium production, both of which are critical to fusion power. Because of their overall desirable properties, lithium-containing ceramic solids are recognized as attractive tritium breeding materials for fusion reactor blankets. Indeed, their inherent thermal stability and chemical inertness are significant safety advantages. In numerous in-pile experiments, these materials have performed well, showing good thermal stability and good tritium release characteristics. Tritium release is particularly facile when an argon or helium purge gas containing hydrogen, typically at levels of about 0.1%, is used. However, the addition of hydrogen to the purge gas imposes a penalty when it comes to recovery of the tritium produced in the blanket. In particular, a large amount of hydrogen in the purge gas will necessitate a large multiple-stage tritium purification unit, which could translate into higher costs. Optimizing tritium release while minimizing the amount of hydrogen necessary in the purge gas requires a deeper understanding of the tritium release process, especially the interactions of hydrogen with the surface of the lithium ceramic. This paper reviews the status of ceramic breeder research and highlights several issues and data needs.
Date: February 2, 1998
Creator: Johnson, C.E.
Partner: UNT Libraries Government Documents Department

Studies of fusion reactor blankets with minimum radioactive inventory and with tritium breeding in solid lithium compounds: a preliminary report

Description: The feasibility of fusion reactor blankets with low residual activity is examined. Several designs are examined with regard to activation, tritium breeding ratio, mechanical design, tritium removal from the blanket, and thermal cycle efflciency. Using aluminum (SAP) as a structural material, it should be possible to build CTR blankets with ~10 curies/MW(e) of long-lived (half life one day or greater) residual activity (other than tritium), which is many orders of magnitude less than with Nb or stainless steel blankets. In the designs examined in this study, tritium is bred in -solid-lithium-containing materials, e.g., LiAl alloy, which have high-equilibrium tritium pressures. The tritium diffuses into either the helium-coolant stream, from which it is removed by absorption, or into the vacuum region between the first wall and plasma. Depending on processing methods and blanket parameters, the tritium blanket inventory should range from 10/sup 2/ to 10/sup 3/ curies/ MW(e). Tritium breeding ratios range from 0.9 to 1.5 depending on blanket design, while therrnal cycle efficiency is estimated to range from 35% to well over 40%, depending on design. Several module designs are developed in which helium-coolant exit temperatures are substantially above the operating temperature limit (~400 deg C) for the aluminum (SAP) structure. (auth)
Date: June 1, 1973
Creator: Powell, J.R.; Miles, F.T.; Aronson, A. & Winsche, W.E.
Partner: UNT Libraries Government Documents Department

Additional results concerning cross-section sensitivity of tritium breeding in a fusion reactor blanket: $sup 6$Li, $sup 7$Li, and $sup 93$Nb

Description: Previous work concerning cross-section sensitivity of the tritium breeding ratio showed ine effects of altering a partial cross section independently of other partial cross sections, permitting the total cross section to rise or fall. The results reported here are mostly for variations made while keeping the total cross section constant. The cases considered were for high and low values of the cross sections for /sup 6/Li(n, )t,/sup 7/Li(n, n' alpha )t, and for /sup 93/Nb(n2n) with compensatory changes in other cross sections. The general conclusions of previous work have been borne out both qualitatively and quantitatively under the present more realistic ground rules. In addition, results are reported for a modified CTR benchmark which has blanket material in place of the graphite reflector. This case shows a drop of 0.13 in /sup 6/Li productions, a rise of 0.02 in /sup 7/Li productions, and an increase of 0.15 in neutron leakage. (auth)
Date: January 1, 1974
Creator: Tobias, M. & Steiner, D.
Partner: UNT Libraries Government Documents Department