• Carbon letters
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• 제16권4호
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• pp.233-240
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• 2015

Electrochemical synthesis was employed to prepare a novel hydroxyapatite/graphene (HAP/Gr) composite powder suitable for medical applications as a hard tissue implant (scaffold). The synthesis was performed in a homogeneous dispersion containing Na₂H₂EDTA·2H₂O, NaH₂PO₄ and CaCl₂ with a Ca/EDTA/PO₄³⁻ concentration ratio of 0.25/0.25/0.15M, along with 0.01 wt% added graphene nanosheets, at a current density of 137 mA cm⁻² and pH value of 9.0. The field emission scanning electron microscopy and transmission electron microscopy observations of the composite HAP/Gr powder indicated that nanosized hydroxyapatite particles were uniformly placed in the graphene overlay. Raman spectroscopy, Fourier transform infrared spectroscopy and X-ray diffraction confirmed graphene incorporation in the HAP/Gr powder. The electrochemically prepared HAP/Gr composite powder exhibited slight antibacterial effect against the growth of the bacterial strain Staphylococcus aureus.

• Wind and Structures
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• 제25권2호
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• pp.177-193
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• 2017

The accelerated development of new materials, technologies and construction processes, in parallel with advances in computational algorithms and ever growing computational power, is leading to more daring and innovative architectural and structural designs. The search for non-regular building shapes and slender structures, as alternative to the traditional architectural forms that have been prevailing in the building sector, poses important engineering challenges in the assessment of the strength and mechanical stability of non-conventional structures and systems, namely against highly variable actions as wind and seismic forces. In case of complex structures, laboratory experiments are a widely used methodology for strength assessment and loading characterization. Nevertheless, powerful numerical tools providing reliable results are also available today and able to compete with the experimental approach. In this paper the wind action on a free-form complex thin shell is investigated through 3D-CFD simulation in terms of the pressure coefficients and global forces generated. All the modelling aspects and calibrating process are described. The results obtained showed that the CFD technique is effective in the study of the wind effects on complex-shaped structures.

• 대한치과교정학회지
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• 제2권1호
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• pp.35-40
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• 1971

Since malocclusion affects a large segment of the population, it is by definition a public health problem. The etiology ana treatment of malocclusions have been studied by clinicians; however epidemioloic aspect of tile problem have been neglected. This study was undertaken using Angle's classification to obtain and to evaluate epidemiologic data on the prevalence of malocclusion in a group of 2,378 Yonsei University students, 17 to 23 years of age. All freshmen were selected, except for those students receiving orthodontic treatment and those few with too many missing teeth which prohibits classification by Angle's method. The following results were obtained: 1) Almost $91\%$ of students had malocclusion of the teeth severe enough to require correction. 2) There was a statistically significant difference in malocclusion between males and females($93.66\%$ malocclusion in males, $79.13\%$ malocclusioa in females). 3) Crowding was most pravalent in class I malocclusion. 4) There appeared to be a specific association between the number of lost first molars and Angle's classification. 5) In this study, more class II, Div.2 malocclusion appeared than in Massier's and Frankel's study of Caucasians, which used similar criteria. Class III malocclusion was more prevalent than normal occlusion in the Korean students studied, but in Caucasians' normal occlusion was more prevalent.

• Journal of Nutrition and Health
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• 제12권2호
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• pp.65-74
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• 1979

In order to observe the contents of some essential amino acids in Korean foods, total and free tryptophan, and available lysine in fifty kinds of Korean foods were analyzed by the sfectrophotometry. The results obtained are summarized as follows : 1) The tryptophan contents per 100g of soybean, wet green laver and skim milk were over 250 mg, and the contents Per g nitrogen in ginger, dried persimmon and chestnut were over 150 mg. 2) The free tryptophan contents per 100 g of soybean, small red bean, dried persimmon, ginseng stem were over 100 mg, ana the contents per g nitrogen in dried persimmon was over 150 mg. 3) The available lysine contents Per 100g of soybean, wet green laver and skim milk, fish(auchovy), dried yeast, casein and silkworm pupa were over 1000 mg, and the contents per g nitrogen in potato, perilla(wild sesame), red pepper, sausage and skim milk were over 300mg. 4) The contents of tryptophan and available lysine in soybean, green laver and skim milk were higher than in other samples. 5) In general, the contents of tryptophan and available lysine were abundant in seaweeds.

• 한국식품조리과학회지
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• 제3권1호
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• pp.54-63
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• 1987

The amino acids ana fatty acids of cowpea were determined and physicochemical properties of cowpea starch and rheological properties of cowpea starch gel were investigated. The results were as following: The proteins of cowpea were particularly rich in glutamic acid (20.02%) and aspartic acid (12.21%) and contained considerable amount of leucine (8.99%), lysine (7.20%) and tryptophan (1.81%), whereas were poor in sulpho-containing amino acids. The lipids of cowpea were mainly composed of 31,43% linoleic acid, 28.34% linolenic acid, 22.9% palmitic acid and 7.63% oleic acid and the small amount of myristic, arachidonic and behenic acid was contained. The ratio of the saturated to the unsaturated in cowpea oil was 32~33/67~68. Cowpea starch gel showed lower values for hardness and brittleness than mung been starch gel, whereas a higher value for cohesiveness than mung bean starch gel, Cowpea starch gel showed lower values for $E_H$, $E_V$ than mung bean starch gel, whereas higher values for $n_V$, $n_N$ than mung bean starch gel. Cowpea starch gel had a lower value for elasticity than mung bean starch gel and had a higher value for viscosity than mung bean starch gel.

• The Journal of Korean Physical Therapy
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• 제12권1호
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• pp.79-86
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• 2000

The purpose of this study was analyse the necessity for the Scam work at home care service. The subjects of the study were 14 home m nurses who work in community and in physical ana 16 physical therapist. The data were collected from Sep. 1 to Dec. 31, 1999. The result were analysed statistically by $X^2$, t-test. The main results of this study were as follows : 1. There were statistical significances of the general characteristics between the physical therapists and the home care nurses, 2. There were statistical significances of currencies of the home us service which the subjects experienced. 3. There were no statistical significances of the necessity of team work and the participation in home care service. 4. Regarding the effects of expectation which consisted 9 items, there were statistical significances in 8 items.

• 한국의류학회지
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• 제20권5호
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• pp.783-791
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• 1996

The effect of alkali treatment on the changes in characteristics, mechanical properties, and hand of polyester fabrics was studied. Two kinds of fabrics having different yarn deniers were treated varying weight loss. The results were as follows; 1. Changes in constructional characteristics by alkali treatment were: a decrease in weight & thickness of fabric, a decrease in yarn denier, a decrease in apparent density of fabric, an increase in porosity to air, and a change fiber surface. 2. As for the changes in mechanical properties by alkali treatment, findings were : an increase in WT, RT, MIU, LC, and WC, a decrease in LT, B,2HB, G,2HG,2HGS, MMD, SMD, and RC, ana an increase in drape. 3. Changes in hand by alkali treatment were: a decrease in KOSHI and HARE, an increase in FUUURAMI, SHARI, KISHIMI, and SHENAYAUASA, and an increase in T.H.V 4. In the case of the same weight loss, the hand of 40/24 fabric being composed of thinner yarns was better than the hand of 50/24 fabric. 5. When 50/24 fabric was treated to have the same weight with 40/24 fabric, so the yam deniers of two fabrics were the same, the hand of 50/24 fabric having larger weight loss was better than the hand of 40/24 fabric.

• 한국의류학회지
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• 제9권1호
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• pp.29-34
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• 1985

The purpose of this study was to investigate two aspects of high school boys' clothing attitudes as compared with their family value orientations and sex role attitudes. Family value orientations were measured through the Home Environment Inventory (Won Sik Jung: 1970). Sex role attitudes were measured through Osmond and Martin's Sex Role Attitude Scale. Clothing Attitudes: 1) Clothing Modesty was assessed by means of Kim; Won: Kim: and Lee's questionnaires, 2) Clothing Importance n?as assessed by means of Jung: Park: ana. Kirby'a questionnaires. The questionnaires were administered to a sample of 561 senior high school boys in Seoul. The data was analyzed by correlation. The results were as follows: 1) Traditional family value orientation was positively related to Clothing Modesty. 2) Materialistic family value orientation was positively related to Clothing Importance. 3) Sex role attitudes were not related to Clothing Importance and Clothing Modesty. 4) The attitude for the clothes controlled to wear is different with each other among the students, parents and teachers.

• 한국수산과학회지
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• 제6권3_4호
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• pp.97-100
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• 1973

In the previous work(Kim et al, 1973), the quality of sun-dried Alaska pollack, Theragra chalch-ogramma, was discussed in the aspect of non-enzymatic discoloration as a function of relative humidity during storage at room temperature($20^{\circ}C$). In this paper, sun-dried squid, Ommastrephes steam pacificus was investigated at the same aspect mentioned above. Fresh squid from the whole sale market was dressed, filleted, dried for 48 hours in the open air and finally stored in the humidistat chamber. Lipid oxidation ana development of non-enzymatic browning were tested by the same methods described in the previous paper. The TBA value showed a maximum peak on 30 day storage, hereafter tended to decrease gradually. The rate of browning, however, in water soluble fraction as well as in chloroform-methanol fraction was lower at 0.34 to 0.45 water activity than at any other case, and propagation of lipid oxidation was also diminished at the above level of water activity. From the results, it is recognized that storage at Aw=0.34 to 0.45 provides higher quality stability for sun-dried squid.

• Journal of Microbiology
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• 제44권3호
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• pp.276-283
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• 2006

The thermophilic fungus Thermoascus aurantiacus 179-5 produced large quantities of a glucosidase which preferentially hydrolyzed maltose over starch. Enzyme production was high in submerged fermentation, with a maximal activity of 30 U/ml after 336 h of fermentation. In solid-state fermentation, the activity of the enzyme was 22 U/ml at 144 h in medium containing wheat bran and 5.8 U/ml at 48 h when cassava pulp was used as the culture medium. The enzyme was specific for maltose, very slowly hydrolyzed starch, dextrins (2-7G) and the synthetic substrate (${\alpha}$-PNPG), and did not hydrolyze sucrose. These properties suggest that the enzyme is a type II ${\alpha}$-glucosidase. The optimum temperature of the enzyme was $70^{\circ}C$. In addition, the enzyme was highly thermostable (100% stability for 10 h at $60^{\circ}C$ and a half-life of 15 min at $80^{\circ}C$), and stable within a wide pH range.