• Journal of the Korean Magnetics Society
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• v.17 no.2
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• pp.81-85
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• 2007

MnTe layers of high crystalline quality were successfully grown on Si(100) : B and Si(111) substrates by molecular beam epitaxy (MBE). Under tellurium-rich condition and the substrate temperature around $400^{\circ}C$, a layer thickness of $700{\AA}$ could be easily obtained with the growth rate of $1.1 {\AA}/s$. We investigated the structural, magnetic and transport properties of MnTe layers by using x-ray diffraction (XRD), superconducting quantum interference device (SQUID) magnetometry, and physical properties measurement system (PPMS). Characterization of MnTe layers on Si(100) : B and Si(111) substrates by XRD revealed a hexagonal structure of polycrystals with lattice parameters, ${\alpha}=4.143{\pm}0.001{\AA}\;and\;c=6.707{\pm}0.001{\AA}$. Investigation of magnetic and transport properties of MnTe films showed anomalies unlike antiferromagnetic powder MnTe. The temperature dependence of the magnetization data taken in zero-field-tooling (ZFC) and field-cooling (FC) conditions indicates three magnetic transitions at around 21, 49, and 210 K as well as the great irreversibility between ZFC and FC magnetization in the films. These anomalies are attributable to a magnetic-elastic coupling in the films. Magnetization measurements indicate ferromagnetic behaviour with hysteresis loops at 5 and 300 K for MnTe polycrystalline film. The coercivity ($H_c$) values at 5 and 300 K are 55 and 44 Oe, respectively. In electro-transport measurements, the temperature dependence of resistivity revealed a noticeable semiconducting behaviours and showed conduction via Mott variable range hopping at low temperatures.

• Korean Journal of Poultry Science
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• v.15 no.2
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• pp.81-91
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• 1988

The purpose of this research is to analyze the tendencies of poultry consumption in Korea. The information used is the data collected three times during the period from Sept. 1, 1985 to April 30, 1987 throughout the major cities. Those who participated in the survey are 2, 598 including housewives, nutritionists, cookers, group feeding institutions, woman's organizations, and the students of doing nutrition－related studies. Consumer preferences for poultry meat and eggs tend to move toward high quality and more strict sanitary standards. Following this line of consumer preference changes, the poultry product marketing supported by cold chain system is rapidly developing. Household consumption of poultry meat largely consists of hi－and semi－broilers but the household demand for these two broilers tends to decrease steadily over time. In general poultry meat consumption appears to be affected by consumer taste rather than market factors such as prices. In addition consumer choices are quite different depending on poultry meat parts which are preferred in order of drum sticks, wings, and breasts. In particular drum sticks are most preferred than any other parts. An important problem in poultry production is related to consumption seasonality since large part of poultry meat consumption is concentrated during the summer season. Another problem is associated with little development of cooking methods. At present there are two types of primary commercial cooking techniques, fries and samgaetang (boiled chicken with jinsang and rice). For promoting domestic poultry meat disposal and reducing the demand seasonality, new cooking methods should be developed and followed by more aggresive advertisements. In domestic egg trade, smaller packing units(i.e., 10 eggs per unit) tend to bi preferred to large ones (i.e., 30 eggs per unit). In consumers egg purchasing decisions nearness to the shops and convenience appear to be important factors. For egg shell colors consumers recognize that there is no difference in nutritional values. However, survey results show that consumers highest preference lies in eggs with brown color. Eggs are most popular among children and preferred in order of middle－and high－school students, 17-25 age people, and adults. Egg prices are concieved relatively cheap to its nutritional values. In house－holds eggs are consumed in the forms of fries, side dishes, and lunch basket dishes. However, high level of cholesterol content in eggs appears to be an important problem in promoting eggs consumption.