• Asian-Australasian Journal of Animal Sciences
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• v.16 no.4
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• pp.609-624
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• 2003

The genesis of methods for defining the nutritional value of feeds and the nutrient requirements of animals, and their development in the late 19th and early 20th centuries in Europe and the USA are outlined. Current energy and protein feeding systems for ruminants are described. Particular reference is made to the Australian systems which are applicable to grazing animals as well as to those given prepared feeds, and enable the effective nutritional management of a imals at pasture by means of the decision support tool GrazFeed. The scheme for predicting intakes by cattle and sheep from pastures allows for the effects of selective grazing on the composition of the feed eaten, and for reduction in herbage intake when a supplementary feed is consumed. For herbage of any given concentration of metabolizable energy (ME) in the feed dry matter the changes with season of year in the net efficiency of use of the ME for growth and fattening and in the yield of microbial crude protein, g/MJ ME, which both vary with latitude, are defined. An equation to predict the energy requirements for maintenance (MEm) of both cattle and sheep includes predictions of the additional energy costs incurred by grazing compared with housed animals and the cost, if any, of cold stress. The equation allows for the change in MEm with feed intake. A flexible procedure predicts the composition of liveweight gain made by any given breed or sex of cattle and sheep at any stage of growth, and the variation with rate of gain. Protein requirements for maintenance, production including wool growth, and reproduction, are related to the quantities of microbial true protein and undegraded dietary protein truly digested in the small intestine.

• Journal of Ocean Engineering and Technology
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• v.25 no.2
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• pp.134-144
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• 2011

In this paper, the global study trends for material behaviors are investigated regarding the static and dynamic hardenings and final fractures of marine structural steels. In particular, after reviewing all of the papers published at the 4th and 5th ICCGS (International Conference on Collision and Grounding of Ship), the used hardening and fracture properties are summarized, explicitly presenting the material properties. Although some studies have attempted to employ new plasticity and fracture models, it is obvious that most still employed an ideal hardening rule such as perfect plastic or linear hardening and a simple shear fracture criterion with an assumed value of failure strain. HSE (2001) presented pioneering study results regarding the temperature dependency of material strain hardening at various levels of temperature, but did not show strain rate hardening at intermediate or high strain rate ranges. Nemat-Nasser and Guo (2003) carried out fully coupled tests for DH-36 steel: strain hardening, strain rate hardening, and temperature hardening and softening at multiple steps of strain rates and temperatures. The main goal of this paper is to provide the theoretical background for strain and strain rate hardening. In addition, it presents the procedure and methodology needed to derive the material constants for the static hardening constitutive equations of Ludwik, Hollomon, Swift, and Ramberg-Osgood and for the dynamic hardening constitutive equations of power from Cowper-Symonds and Johnson-Cook.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.5
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• pp.742-749
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• 2003

Failure of a pipeline due to local wall thinning is getting more attention in the nuclear power plant industry. Although guidelines such as ANSI/ASME B31G and ASME Code Case N597 are still useful fer assessing the integrity of a wall thinned pipeline, there are some limitations in these guidelines. For instance, these guidelines consider only pressure loading and thus neglect bending loading. However, most Pipelines in nuclear power plants are subjected to internal pressure and bending moment due to dead-weight loads and seismic loads. Therefore, an assessment procedure for locally wall thinned pipeline subjected to combined loading is needed. In this paper, three-dimensional finite element(FE) analyses were performed to simulate full-scale pipe tests conducted for various shapes of wall thinned area under internal pressure and bending moment. Maximum moments based on true ultimate stress(${\alpha}$$\sub$u,t/) were obtained from FE results to predict the failure of the pipe. These results were compared with test results, which showed good agreement. Additional finite element analyses were performed to investigate the effect of key parameters, such as wall thinned depth, wall thinned angle and wall thinned length, on maximum moment. Also, the effect of internal pressure on maximum moment was investigated. Change of internal pressure did not show significant effect on the maximum moment.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.12
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• pp.1153-1157
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• 2013

A steam turbine blade is one of the core parts in a power plant. It transforms steam energy into mechanical energy. It is installed on the rim of a rotor disk. Many failure cases have been reported at the final stage blades of a low-pressure (LP) turbine that is cyclically loaded by centrifugal force because of the repeated startups of the turbine. Therefore, to ensure the safety of an LP steam turbine blade, it is necessary to investigate the fatigue strength and life. In this study, the low cycle fatigue life of an LP steam turbine blade is evaluated based on actual damage analysis. To determine the crack initiation life of the final stage of a steam turbine, Neuber's rule is applied to elastic stresses by the finite element method to calculate the true strain amplitude. It is observed that the expected life and actual number of starts/stops of the blade were well matched.

• Applied Microscopy
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• v.3 no.1
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• pp.29-38
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• 1973

Introduction. The human cutaneous scars manifest themselves many ways in different types according to the factors such as the age, sex, race of the patient as well as the location,. kind and heal ing process of the wound. Among the scars it is quiet difficult to verify the clinical course of the hypertrophic or keloidal scars from the true keloids. However, clinical observations indicate that stress, either mechanical or in the forms of chronic infections, can induce a functional change in the fibroblasts causing an excessive production of collagenous matrix. In this study, we preliminary attempt to justify any difference of the cellular structure between keloids and hypertrophic scars by using electron microscope. Material and Methods. A total of 23 cases: 2 scars, 2 hypertrophic scars and 19 keloids are examined. Immediately, the biopsy tissue was fixed in 10% neutral formalin and 4% glutaraldehyde solution in phosphate buffer for 4 hours, post fixed in 1 % osmium tetraoxide for two hours, dehydrated with graded alcohol, and embedded in Epon 812. Thick sections were stained with hematoxylin eosin, periodic acid-Schiff(PAS) and Van Gieson stain. Thin sections were cut and uranyle acetate, lead citratestain and examined with the electron microscope. Result. The morphologic features of keloid showed thick, homogenously eosinophilic bands of collagen and numberous large active fibroblasts. The hypertrophic scar and soft scar are more cellular than keloid and composed thinner collagenous fiber. For this paper in the etiology of keloids can not as be defined, but and interesting keloidal tissue fibroblast showed irregular nucleus with irregular shape dense bodies and fibril materials contained in to the cytoplasm.

• Horticultural Science & Technology
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• v.32 no.2
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• pp.227-234
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• 2014

The responses to chilling temperature of 12 Korean cucumber varieties was compared to those of two U.S.A. (previously determined cold tolerant NC76 and 'Chipper'), and Chinese and Japanese germplasms. Seedlings of each entry were exposed to $4^{\circ}C$ (Experiment 1) and $1^{\circ}C$ (Experiments 2 and 3) at the first-true leaf stage for eight and nine hours, respectively, under 80% relative humidity (RH) and $149{\mu}moles{\cdot}m^{-2}{\cdot}s^{-1}$ photosynthetic photon flux (PPF). The chilling response [damage rating (DR)] of each accession was based on visual ratings (1 to 5) after treatment, where 1 = no damage, 2 = slight, 3 = moderate, 4 = advanced, and 5 = severe damage. Predictably the cumulative average DR of chilling tolerant line NC76 and 'Chipper' after chilling w as 1 and 1.1, respectively. Korean 'Nacdongchungjang' was most sensitive to chilling temperatures [DR = 2.3] when compared to the other entries examined. The sensitivity to chilling of 'Nacdongchungjang' was followed by Chinese 'Dongguan' [DR = 1.7]. In contrast, 'Saeronchungjang' (DR = 1) and 'Janghyungnachap' (DR = 1) were the most chilling tolerant of the Korean accessions examined and equivalent to the response of line NC76 and 'Chipper'. Nevertheless, chloroplast type genotyping of these accessions with known chilling-linked sdCAPS genomic markers revealed genotypic differences between chilling tolerant lines (NC76 and 'Chipper') and all Korean lines examined.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.486-496
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• 2018

Customer incivility is an important stress factor employees performing service tasks, and this is equally true for employees who perform civil affairs services. The purpose of this study is to investigate the negative effects of adverse customer behavior and ways to reduce it. This study adopts the Conservation of Resource (COR) theory in order to examine customer incivility. This study predicts that customer incivility will negative emotions and eventually lead to emotional exhaustion in employees. We also predict that social support (organizational support, supervisor support, coworker support) perceived by employees would moderate the relationship between customer incivility and negative emotions. This study is based on 481 questionnaires collected from public officials. The results are as follows: First, customer incivility causes negative emotions. Second, negative emotions mediate the relationship between customer incivility and emotional exhaustion. Third, the relationship between customer incivility and negative emotions showed moderating effects on the perception of organizational support which is one of three types of social support. Based on the results of this study, implications, limitations, and future direction of research are suggested.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.11 no.1
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• pp.144-149
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• 2000

A psychogenic seizure is a disorder which is occasionally met by neurologists and psychiatrists. The most important thing that clinicians should do is differential diagnosis with true epileptic seizures. Especially psychiatrists are expected to be able to diagnose psychogenic seizures through a thorough history taking and an observation of clinical features to some degree before the confirmatory diagnoses. We experienced a case of 11-year-old girl with psychogenic seizure which was characterized by obvious psychological and environmental stress, clinical features, and good outcome by prompt a loboratoy examination and psychiatric intervention. To diagnose and treat childhood psychogenic seizures, we suggest that it is very important to examine the familial background and take a thorough history, and perform psychoeducational intervention in addition to electroencephalogram.

• The Korean Journal of Rheology
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• v.8 no.3_4
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• pp.199-206
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• 1996

산마와 재배마에서 점질다당류를 추출하여 리올러지 및 열특성을 연구하였다. D.I.W 에서 산마와 재배마 점질다당류의 고유점도(η)는 각각 16.1 이/g. 25.1 이/g 이고 pH7일 때 최대값을 나타내었고 염을 가했을 때 (η)가 급격히 감소하다가 일정한 값을 나타내었으며 urea 용액에서 NaCl, MaCl2 용액에서보다 (η)가 높았다. 마 점질다당류의 chain stiffness는 0,0050이고 Overlap parameter는 산마와 재배마 점질다당류가 각각 0.06 g/이. 0.04 g/이였 다. 마 점질 다당류는 shear rate가 증가함에 따라 겉보기 점도가 감소하여꼬 농도가 증가함 에따라 yield stress 와 점조성 지수는 증가하고 shear index가 감소하는 가소성유동체였다. 산마 점질다당류는 35$^{\circ}C$까지 온도에 대하여 비교적 안정하였지만 그이상의 온도에서는 겉보 기 점도가 급격히 감소하였고 재배마 점질다당류는 온도가 증가할수록 겉보기 점도가 점차 적으로 감소하였다. 겉보기 점도는 1가 염가 2가 염 사이에 큰 차이가 없었고 염농도가 증 가함에 따라 겉보기 점도가 감소하였으나 urea를 첨가했을 때 겉보기 점도가 약간 감소하다 가 다시 증가하는 것을 알수 있었다. DSC로 산마와 재배마 점질다당류의 "true melting"을 측정했을 때 각각 92$^{\circ}C$, 93$^{\circ}C$였고, enthalpy는 67.06 cal/g, 75.83 cal/g였다. 겔화에 소요된 enthalpy는 pH가 증가할수록 큰 값을 나타냈고 NaCl을 첨가했을 때 감소하다가 염농도 증 가에는 영향을 받지 않았으며 Urea와 glycerol을 각각 첨가했을 때 D. I. W.오세보다 감소 하였다. TGA로 열분해 현상을 측정했을 때 분해 온도는 산마와 재배와 점질다당류가 각각 219~332$^{\circ}C$, 229~341$^{\circ}C$ 범위였다.TEX> 범위였다.

• Journal of the Microelectronics and Packaging Society
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• v.8 no.4
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• pp.25-33
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• 2001

Sn-3.5Ag-xBi alloys with five different levels of Bi (0, 2.5, 4.8, 7.5, 10 wt%) were prepared for evaluating creep properties. Cast alloys were roiled and heat treated to provide stable microstructures during the subsequent creep tests, which were conducted under constant load using dog-bone specimens. For the Bi containing alloys, creep strength showed the maximum around 2.5 wt%Bi and tended to decrease with increasing Bi content. The stress exponent of the alloy was around 4, suggesting typical dislocation creep, but the exponent was 2 for the 10 wt%Bi alloy, suggesting creep assisted by grain boundary Sliding. For the Bi containing alloys, the brittle fracture mode appeared showing small amount of reduction of area, while the ductile fracture mode was true for the Bi free alloy. Microstructural examination of ruptured specimens showed cavitations on grain boundaries normal to the load axis, and a significant of grain boundary sliding for the Bi containing alloys.