• Journal of Preventive Medicine and Public Health
• /
• v.32 no.4
• /
• pp.467-472
• /
• 1999

Objectives: This study was conducted to evaluate the cytotoxicity of gallium arsenide(GaAs), indium phosphide(InP) and indium arsenide(InAs) all of which are used a$ the semiconductor eletments in semiconductor industry. Methods: Cytotoxicity id the alveolar macrophage was evaluated by the measurement of in vitro magnetometry, LDH release assay and histological examination. Results: The relaxation curves by the in vitro magnetometry showed that GaAs has the cytotoxicity for the alveolar macrophage which is more significant in the higher dosages, while this cytotoxicity is not appeared in the groups added with InP or InAs or PBS. In the decay constant for two minutes after magnetization, GaAs-added groups showed a significant decrease with increasing doses, but both InP- and InAs-added groups did not show any significance. The LDH release assay showed a dose-dependent increasing tendency in the GaAs-, InP- and InAs-added groups. In terms of cellular morphological changes, GaAs-added groups revealed such severe cellular damages as prominent destructions in cell membranes and their morphological changes of nucleus, while InP- and InAs-added groups remained intact in intracellular structures, except for cytoplasmic degenerations. Conclusions: It is suggested that GaAs is more influential to cytotoxicity of alveolar macrophages than InP and InAs.

• Clinical Nutrition Research
• /
• v.5 no.3
• /
• pp.172-179
• /
• 2016

Acid food indicators can be used as pH indicators for evaluating the quality and freshness of fermented products during the full course of distribution. Iron oxide particles are hardly suspended in water, but partially or completely agglomerated. The agglomeration degree of the iron oxide particles depends on the pH. The pH-dependent particle agglomeration or dispersion can be useful for monitoring the acidity of food. The zeta potential of iron oxide showed a decreasing trend as the pH increased from 2 to 8, while the point of zero charge (PZC) was observed around at pH 6.0-7.0. These results suggested that the size of the iron oxide particles was affected by the change in pH levels. As a result, the particle sizes of iron oxide were smaller at lower pH than at neutral pH. In addition, agglomeration of the iron oxide particles increased as the pH increased from 2 to 7. In the time-dependent aggregation test, the average particle size was 730.4 nm and 1,340.3 nm at pH 2 and 7, respectively. These properties of iron oxide particles can be used to develop an ideal acid indicator for food pH and to monitor food quality, besides a colorant or nutrient for nutrition enhancement and sensory promotion in food industry.

• Journal of the Korean Society of School Health
• /
• v.12 no.2
• /
• pp.231-242
• /
• 1999

This study was designed to identify the relation between health beliefs and compliance with weight control behavior in obese high school students living in Chonnam province. The data were collected from May 24 to 29, 1999. The instruments used in this study were modified by the authors on the basis of the results of the study's related references. The data were analyzed by descriptive statistics, t-test, ANOVA, Pearson's Correlation using the SAS PC+ program. The results were as follows : 1. The correlation between health concern and compliance with weight control behavior was revealed as statistically significant (r= .34, p= .005). From the correlation of variables, it is concluded that there were statistically significant relations between health concern and benefit (r= .25, p= .043), between health concern and barrier (r= .33, p= .008), between susceptibility and severity (r= .64, p= .000), between susceptibility and benefit (r= .42, p= .000), between susceptibility and barrier (r= .44, p= .003), between severity and benefit (r= .37, p= .002), between severity and barrier (r= .56, p= .000), and between benefit and barrier (r= .38, p= .002). Thus, perceived susceptibility, perceived severity, perceived benefit, and perceived barrier had an indirect influence on compliance with weight control behavior. 2. In the analysis of the relationship between general characteristics and compliance with weight control behavior and health belief variables: Sex (t=2.56, p= .010) was revealed as the influencing variable of health concern. The number of those subjects living together (F=2.88, p= .044) was revealed as the influencing variable of susceptibility. Sex (t=3.47, p= .047), income (F=1.67, p= .051) was revealed as the influencing variable of barrier. 3. In the analysis of the relationship between obese characteristics and compliance with weight control behavior and health belief variables: Perception of weight (F=9.21, p= .000), family history of obesity (t=4.89, p= 030), environment of obesity (t=14.30, p= .000) were revealed as the influencing variables of susceptibility. Perception of weight (F=4.86, p= .001), symptoms of obesity (t=4.46, p= .006), family history of obesity (t=6.59, p= .012), environment of obesity (11.30, p= .001), and reasons of weight control (F=3.07, p= .010) were revealed as the influencing variables of severity. Symptoms of obesity (F=4.15, p= .009), reasons of weight control (F=2.41, p= .046) were revealed as the influencing variables of benefit. Environments of obesity (t=4.23, p= .044) were revealed as influencing variables of barrier. These results suggest that for improvement in compliance with weight control behavior, school nurses should stimulate the students' concerns about health.

• Journal of the Korean Society for Precision Engineering
• /
• v.5 no.1
• /
• pp.50-62
• /
• 1988

An experimental investigation of the machining characteristics of compact vermicular cast iron whose matrix were formulated under two kinds of annealing conditions has been conducted. The various characteristics of the machinability of CA cast iron depending upon its matrix and cutting condition have been obtained from the experiment. The results are as follow. As depth of cut increases, the shear stress slightly decreases in order $P_1, \P_2, \P_3$ which are classified by ferrite matrix of CV cast iron. As depth of cut increases, the normal stress increases, and annealing effect in heavy cutting is smaller than that in light cutting. The cutting energy slightly decreases, as depth of cut increases and the effect of annealing on cutting energy in light cutting is higher than that in heavy cutting. The cutting equation in this study are as follow. $P_1\:\2{\phi}\ + \1.49({\beta} - {\alpha} )=84^{\circ}$ $P_2\:\2{\phi}\ + \1.36({\beta} - {\alpha} )=82^{\circ}$ $P_3\:\2{\phi}\ + \1.34({\beta} - {\alpha} )=79^{\circ}$ Machining constants in this study for $P_1, P_2, P_3$give $74^{\circ} , 66^{\circ}, 61^{\circ}$ Tool wear increases as depth of cut increases, and decreases as ferrit matrix increases.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.30 no.6
• /
• pp.372-375
• /
• 2017

ZnO thin films were deposited by RF magnetron sputtering and then diffused by using an As source in the ampouletube. Also, the ZnO p-n homojunction was made by using As-doped ZnO thin films, and its properties were analyzed. After the As doping, the surface roughness increased, the crystal quality deteriorated, and the full width at half maximum was increased. The As-doped ZnO thin films showed typical p-type properties, and their resistivity was as low as $2.19{\times}10^{-3}{\Omega}cm$, probably because of the in-diffusion from an external As source and out-diffusion from the GaAs substrate. Also, the ZnO p-n junction displayed the typical rectification properties of a p-n junction. Therefore, the As diffusion method is effective for obtaining ZnO films with p-type properties.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.6
• /
• pp.793-799
• /
• 2002

Four feeds, three concentrates (rice bran, soybean meal and flaked corn) and one forage (corn silage) were incubated in four ruminally fistulated Holstein steers over three one week periods in a 3${\times}$4 incomplete latin square design where steers served as blocks and feeds as treatment. The objectives of the study were to investigate in situ DM, N and P degradability characteristics of feeds in order to assess availability of these nutrients by ruminants. In each period, all feeds were incubated in quadruplets (corn silage in triplicates) in the rumen of each steer in a reverse order for 3, 6, 9, 12, 18, 24 and 48 h. The DM 'a' fraction was higher and lower (p<0.001) in corn silage and rice bran respectively. Although corn silage contained the lowest (p<0.01) DM 'b' fraction, flaked corn contained the highest. Rate of DM degradation of flaked corn and corn silage were half (p<0.05) of the rate of DM degradation of either rice bran or soybean meal. Potential or effective DM degradability (p<0.05 to 0.001) at various passage rates were the lowest for rice bran and the highest for soybean meal. Corn silage N 'a' and 'b' was the highest and lowest, respectively (p<0.01). N 'c' of corn silage and rice bran was higher (p<0.001) than other feeds. Potential N degradability was the lowest in flaked corn (p<0.05). P 'a' was high (p<0.01) for corn silage and rice bran. P 'b' fraction was very high (p<0.001) in soybean meal but was absent in corn silage. Availability of DM (p<0.01 or 0.001), N (p<0.001) and P (p<0.05) differed between feeds at various passage rates except P availability at k=0.02 per h (p>0.05). The results demonstrate that the availability of DM, N and P by ruminants depends on feed as well as categories of animal.

• Journal of Nutrition and Health
• /
• v.16 no.3
• /
• pp.200-208
• /
• 1983

The present studies were designed to compare the effects of both dietary fat levels and P / S ratio on lipid components in plasma and tissues. Changes in plasma HDL-cholesterol, cholesterol and TG, and also in tissue cholesterol and TG were determined in young rats fed diets providing total dietary fat as 10%, 25% or 45% of calories and P / S ratio as 0.2 or 4.0. Plasma cholesterol levels were getting higher as dietary fat levels increased at P / S 0.2. Plasma cholesterol was lower in rats fed dietary fat either 25% or 45 %, each with P / S 4.0. But at 10% no change in plasma cholesterol were observed by P / S 4.0 because of a possible insufficiency of the absolute amount of PUFA. HDL-cholesterol was rather less sensitive to the modification of dietary fat level, but was reduced in rats fed diets of P / S 4.0 at either 25% or 45% fat, even though HDL-cholesterol were increased in the group of 10% with P / S 0.2. Total cholesterol per g- liver were significantly increased as dietary fat levels increased. Liver cholesterol levels were higher in rats fed diets of P / S 4.0 at higher fat levels (25% or 45%) which possibly suggested that a reduction of plasma cholesterol by high PUFA diet was not at least from a decreased synthesis of cholesterol in liver. However, in muscle no significant differences were found by feeding high P / S ratio at each levels of fat. At 10% fat level, compared to 25% or 45%, cholesterol level was lower in g-liver but higher in g- muscle. Plasma TG was decreased as more dietary fat were supplied at P / S ratio, but no consistant response obtained at low P / S ratio. TG per g-liver were reduced by feeding P / S 4.0 diet at 10% or 45% fat level but no differences were found in muscle. P / S 4.0 diet was more efficient in lowering plasma cholesterol TG and HDL-cholesterolt levels only if fat level was more than 25% of the total calories And young rats were more resistant to dietary fat modification.

• Korean Journal of Materials Research
• /
• v.8 no.5
• /
• pp.419-423
• /
• 1998

The conditions for optimizing mass transport for making buried heterostructure (BH) InGaAsP/lnP lasers are discussed. The double heterostructure InGaAsP/lnP laser structures were grown by Liquid Phase Epitaxy (LPE) and etched into mesas. The active layer was selectively etched along [llO] and the mass transport was carried out in the LPE reactor to cover the sides of the active layer and form a BH structure. The threshold temperature for the appreciable mass transport is measured to be 670$670^{\circ}C$ when the holding time is set to 40 min. The width of the region re¬filled by mass transport is observed to increase as the temperature increases.

• Journal of the Korea Society of Computer and Information
• /
• v.22 no.6
• /
• pp.141-147
• /
• 2017

Along with the recent growth of Fintech industry and low interest rate basis, one of the alternative investment technique for expecting higher investment profit, P2P loan using P2P financial system is greatly increasing. P2P loan can be referred to as a type of Crowdfunding that the law of Crowdfunding (adopted to revised Capital Market Act) enacted on January 25th 2016 only allows investment type Crowdfunding so that it can be used as a tool of raising fund for startup and venture companies. Also, it is true that Korean government could not make any legislative foundation related to P2P loan. At this moment, those online platform companies mediating P2P loan are not included as financial companies, expected to cause various legal arguments. Financial Services Commission has released a guideline in February of this year saying that limit of P2P loan is 10 million Korean Won per arbitrating company and 5 million Korean Won per borrower. However, what is more important is to make a law supporting this institutional system. If legislation on P2P loan is implemented without care, it may disturb growth of the field but it may result in the damage of investors if not clearly defined by law. As this is the case, first, "revision of execution regulations for loan business" should take place as soon as possible to intensify inspection of loan companies by registering them to Financial Services Commission. Second, saving customer fund separately in the their organization. Third, making law on protecting investors such as regulating exaggerative advertisement. Fourth, to have transparent and fair public announcement system, standardized agreement and guideline describing clear understanding on autonomous public information publication of P2P loan online platform business and information on the borrower.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 1999.10c
• /
• pp.411-417
• /
• 1999

This study was performed to figure out an optimum water environment and to obtain the fundamental data related with saving labor and water consumption for the chinese cabbage being grown in greenhouse . The productivity of cabbage cultivated in boty pots and floor were compared to each other in the aspects of height and weight depending on the soil saturation levels. Obtained results are as follows. ; In case of pot cultivation , the height as well as weight of cabbage in 80% soil saturation level(P80) were measured to be larger than those in the other 2 soil saturation leves (P100 and P60). The weight of floor cultivated cabbages were relatively larger than that of pot cultivated ones. In accordance with saturation ration, the general trend of water consumption rate was maximum in P80 and was decreased in the order of P80 , P100 and P60. And the average indoor temperature as well as the plant growth rate were found to be closely related with water consumption rate.