• Environmental Engineering Research
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• 제23권1호
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• pp.54-61
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• 2018

Biodiesel production parameters and the impact analysis of the potential emissions from both soybean biodiesel and washing water stored in three different environmental conditions were investigated. The effects of the reaction temperature, methanol/oil mole ratio and catalyst concentration on biodiesel yield were considered. And the results showed optimum biodiesel yield of 99% obtained at $54^{\circ}C$, 7 methanol/oil mole ratio and 0.4 wt/wt % catalyst concentration. The potential emissions from both the biodiesel produced and washing water stored (for six weeks) in refrigerator (${\leq}10^{\circ}C$), vacuum (50 kPa) and direct exposure to atmosphere were identified and quantified. Impact analysis of the emissions involved their categorization into: terrestrial acidification, freshwater eutrophication, human toxicity, terrestrial ecotoxicity, climate change and freshwater ecotoxicity. Freshwater ecotoxicity category had the most pronounced negative impact of the potential emissions with $5.237710^{-2}kg\;1,4-DB\;eq$. emissions in Atmosphere, $4.702610^{-2}kg\;1,4-DB\;eq$. emissions in Refrigerator and $3.966110^{-2}kg\;1,4-DB\;eq$. emissions in Vacuum. Climate change had the least effect of the emissions with $6.214106^{-6}kg\;CO_2\;eq$. in Atmosphere, $3.9310^{-6}kg\;CO_2\;eq$. in Refrigerator and $1.6710^{-6}kg\;CO_2\;eq$. in Vacuum. The study showed that the order of preference of the storage environments of biodiesel is vacuum environment, refrigerated condition and exposure to atmosphere.

• 한국분말재료학회지
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• 제16권5호
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• pp.336-341
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• 2009

To produce alloy powders with only Sm$_2$Fe$_{17}$ single phase by reduction-diffusion (R-D) method, the effect of excess samarium oxide on the preparation of Sm-Fe alloy powder during R-D heat treatment was studied. The quantity of samarium oxide was varied from 5% to 50% whereas iron and calcium were taken 0% and 200% in excess of chemical equivalent, respectively. The pellet type mixture of samarium, iron powders and calcium granulars was subjected to heat treatment at 1100$^{\circ}C$ for 5 hours. The R-D treated pellet was moved into deionized water and agitated to separate Sm-Fe alloy powders. After washing them in deionized water several times, the powders were washed with acetic acid to remove the undesired reaction products such as CaO. By these washing and acid cleaning treatment, only 0.03 wt% calcium remained in Sm-Fe alloy powders. It was also confirmed that the content of unreacted $\alpha$-Fe in Sm$_2$Fe$_{17}$ matrix gradually decreased as the percentage of samarium oxide is increased. However, there was no significant change above 40% excess samarium oxide.

• 한국보건간호학회지
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• 제11권2호
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• pp.73-82
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• 1997

This study was done to analyze the health behavior of 5.166 elementary students from a urban city. They were students in grades 4. 5 and 6 attending five elementary schools which were selected from a city close to the capital city of Seoul. Health behaviors were measured using a questionnaire which was developed by WHO and was used by European countries. The data was managed and analysed using DBASE and SAS computer programs. The results of this study were as follows: 1. Eating behavior $\cdot$ Having Breakfast : Male students who were older had a higher number reporting having no breakfast(p< .05) $\cdot$ Taking Supplements : Older students had a higher number reporting taking nutrition supplements(p<.05) $\cdot$ Drinking milk: Female students had a lower number reporting drinking milk (p<.05). $\cdot$ Taking snacks : Female students who were older had a higher number reporting taking snacks(p< .05). $\cdot$ Drinking boiled water Male students had a lower number reporting drinking boiled water(p<.05). 2. Using seat belt Female students who were older had a lower number reporting using seat belt(p<.05). 3. Smoking : Male students who were younger had a higher number reporting experience with smoking(p <.05). 4. Personal hygiene $\cdot$ Washing hands before meals : Male students who were younger had a lower number reporting washing hands before meals(p<.05). $\cdot$ Brushing teeth: Male students had a lower number reporting brushing teeth(p<.05). 5. Reading distance : Younger students had a higher number reporting near reading distance(p<.05). 6. Exercise: Female students who were younger reported less exercise(p<.05). 7. Sewage Managing : Male students had a lower number reporting separating of garbage according to recyclability(p<.05).

• Membrane and Water Treatment
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• 제9권1호
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• pp.43-51
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• 2018

Hollow fiber (HF) membranes are gaining wide interest over flat membranes due to their compaction and high area to surface volume ratio. This work addresses the fabrication of HF from polysulfone (PS) and polyethersulfone (PES) using N-methylpyrrolidone (NMP) as solvent in addition to other additives to achieve desired characteristics. The semi-pilot spinning system includes jacketed vessel, four spinneret block, coagulation and washing baths in addition to dryer and winder. Different parameters affecting dry-wet spinning phase inversion process were investigated. Dope compositions of PES, NMP and polyvinyl pyrrolidone (PVP) of varying molecular weights as additive were addressed. Some critical parameters of importance were also investigated. Those include dope flow rate, air gap, coagulation & washing baths and drying temperatures. The measured dope viscosity was in the range from 1.7 to 36.5 Pa.s. Air gap distance was adjusted from 20 to 45 cm and coagulation bath temperature from 20 to $46^{\circ}C$. The HF membranes were characterized by scanning electron microscope (SEM), atomic force microscope (AFM) and mechanical properties. Results indicated prevalence of finger like structure and average surface roughness from about 29 to 78.3 nm. Profile of stress strain characteristics revealed suitability of the fibers for downstream interventions for fabrication of thin film composite membrane. Different empirical correlations were formulated which enable deeper understanding of the interaction of the above mentioned variables. Data of pure water permeability (PWP) confirmed that the fabricated samples fall within the microfiltration (MF)-ultrafiltration (UF) range of membrane separation.

• International Journal of Internet, Broadcasting and Communication
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• 제7권2호
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• pp.96-104
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• 2015

Fischer Tropsch reaction is one of the interesting topic for renewable and clean energy. Polymerization of carbon monoxide or carbon dioxide with hydrogen over metal supported catalyst can produce long chain hydrocarbons. Synthetic liquid hydrocarbons are promising alternative to fossil fuels. This research work has been focused on the synthesis of Fe based catalyst for Fischer Tropsch reaction. Mesoporous silica (MS) support prepared by a precipitation method using two different washing solution, distilled water (DW) and acid in ethanol solution (ET), and different calcination temperature. Then, Fe/MS was prepared by an incipient wetness impregnation method. All of samples were systematically characterized using various physical and chemical techniques. TEM and XRD analysis were used to ensure that the cubic Ia3d mesostructure is stable after calcination. FTIR spectra are useful to ascertain the existence of template in the support. TPR studies were also used to understand the nature of Fe species and their reducibility. The results reveal that washing the support with distilled water and calcination at $550^{\circ}C$ can efficiently remove the triblock copolymer templates. The existence of template in the support affects the textural properties of all catalyst investigated.

• 약학회지
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• 제40권6호
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• pp.659-665
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• 1996

Zinc white is mainly used as a mild astringent, protectant. and has weak antiseptic action. It is well known that the yield of zinc white produced is greatly affected by the syn thetic conditions such as the reactant concentration, reaction temperature, washing water temperature, mole ratio of reactants, and drying temperature, calcination temperature, etc. The purpose of this study is to investigate the optimal synthesis conditions of zinc white produced. A randomized complete block design suggested by G.E.P. Box and K.B. Wilson was applied for this purpose. Basic zinc carbonate was prepared by reacting zinc sulfate and sod. carbonate solution in this study. Zinc white comes when prepared by calcination of basic zinc carbonate. The optimum synthesis conditions of zinc white obtained from this study is as follows: 1) The reacting temperature range is: 92-100$^{\circ}C$, 2) The concentration of reactant solution is 23.6-27%, 3) The optimum mole-ratio: [ZnSO4]/[Na2CO3] is 1.74~1.96, 4) The washing water temperature is 36$^{\circ}C$, 5) The drying temperature range is 68-74$^{\circ}C$, 6) The calcination temperature is 600$^{\circ}C$. The outcome of DSC indicated a desolvation of basic zinc carbonate occurred at about 133.3$^{\circ}C$. The dehydration of the compound ceased at about 267.9$^{\circ}C$ and the decarboxylation ceased at about 379.9$^{\circ}C$. The physical and chemical properties of zinc white as medicine were studied by use of Volume Test.

• 가정과삶의질연구
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• 제28권1호
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• pp.37-49
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• 2010

This study investigated the effects of three factors - children's age, sex and parental feeding styles - on children's self-help skills. The subjects were 213 children and their parents who lived in Kwanak-ku, Seoul. The three-way analysis of variance was employed. The main results were as follows: 1. Children's autonomy was varied significantly according to their sex. Girls do better by themselves than boys do in toileting, washing and drying hands, putting on and buttoning up a coat, putting on clothes, washing and drying their faces. Children's autonomy also varied significantly according to age. A majority of the autonomy subsets increased as the children's ages increased. However, drying their hands with a towel, removing their coats, and drinking water did not vary by age. 2. Children's autonomy also varied significantly according to their parents' feeding style. A responsive feeding style encouraged children to drink water by themselves. 3. The group with the highest score in self-help skills in toileting was 6-year-old girls, and the group with the lowest score was 3-year-old boys. Additionally, the groups with the highest scores in toileting were 4-year-old girls whose parents demonstrated a neglective feeding style, 5-year-old girls whose parents demonstrated an authoritative feeding style, 5-year-old girls whose parents demonstrated a responsive feeding style, 3-year-old boys whose parents demonstrated a responsive feeding style and 6-year-old boys whose parents demonstrated a neglective feeding style. Conversely, the groups with the lowest scores in toileting were 3-year-old girls whose parents demonstrated an authoritarian feeding style, 5-year-old girls whose parents demonstrated a neglective feeding style, and 3-year-old and 6-year-old boys whose parents demonstrated an authoritarian feeding style. 4. The group with the highest score in removing their coats was girls whose parnets demonstrated authoritative, responsive or neglective feeding styles. The group with the lowest score in removing their coats was boys whose parents demonstrated authoritative or neglective feeding styles.

• 한국생활과학회지
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• 제20권2호
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• pp.449-465
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• 2011

This study was performed to investigate the effects of food habits and life style on the skin health of young Korean females in their late teens and twenties. The study focused on facial skin and used a self-administered questionnaire survey, an examination of skin type, and pH tests. More than half of the females had combination skin type or pH level higher than 5.8 which is regarded as normal. The variables that turned out to significantly (p<0.05) effect their facial skin types were body mass index (BMI), the type of residence, the amount of water intake, whether or not they intake drinks, the frequency and amount of alcohol drinking, favorite foods as side dishes at meals, intake frequency of fruit, the dairy, seaweed, and fast food, the frequency of washing their faces per day, the method of how they used water during face washing, whether or not they had professional skin care, and whether or not they wore color make up. The variables of the females' age, BMI, the amount of alcohol drinking, the frequency and duration of exercise, the controlling methods of stress, their favorite foods as side dishes at meals, and the intake frequency of soy products or animal foods significantly affected their facial pH levels (p<0.05). The results of this study indicate that some food habits and life styles are significantly related with facial skin health. More importantly BMI and favorite foods as side dishes during daily food intake could have remarkable effects on facial skin health.

• 한국식품과학회지
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• 제17권2호
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• pp.95-100
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• 1985

콩우유 가공중 부산물로 생산되는 비지를 acetone과 ethanol로 세척한뒤 저온에서 건조하였을때 세척회수가 건조비지의 건조시간(乾燥時間)과 이화학적(理化學的) 성질(性質)에 미치는 영향을 조사하였으며 건조비지가 밀가루와 혼합(混合)될 때 수분과 기름의 흡수능력(吸收能力)의 변화를 측정하였다. 비지와 용매의 비율을 1:1.5로 하여 세척회수(1-5회)가 증가함에 따라 건조속도와 단백질 함량의 증가 그리고 지방과 총당의 감소가 있었으며 수분과 기름의 흡수능력도 증가하였다. 전반적으로 acetone은 3회(回), ethanol은 2회(回) 세척후 이들 성질의 변화가 완만해 졌으며 acetone 세척이 ethanol보다 건조속도나 색상 그리고 지방함량의 감소에서 유리함이 밝혀졌다. 한편, 건조비지를 밀가루와 혼합할때 비지의 혼합비율이 증가하면서 거의 직선적으로 수분과 기름의 흡수능력이 증가됨을 보여 주었다.

• 대한수의학회지
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• 제60권3호
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• pp.105-108
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• 2020

These days abattoirs' hygiene of Korea is regulated by Hazzard Analysis Critical Control Point (HACCP). Although 20 years have been left since first HACCP was adjusted in Korea, 12% of abattoirs got inconsistence on evaluations. Food poisoning caused by bacteria feces like pathogenic Escherichia coli and Salmonella has not decreased. These bacteria on meat cross-contaminate at the abattoir. Therefore, field verification of abattoir's critical control point (CCP) and experiments to find alternative ways of the CCP were conducted. The aerobic bacteria were measured before and after high-pressure water based washing process set as CCP in most abattoirs. Four parts of cattle carcasses were selected to apply sponge-swab method. The effects were < 1 log reduction which is not significant. Lactic acid (LC), chlorine dioxide (ClO₂) and slightly acidic electrolyzed water (SAEW) were used to measure the effect of reducing bacteria on beef by the different time. LC has 1.24-2.02 log reduction for aerobic bacteria. ClO₂ has 1.44-1.96 log reduction for aerobic bacteria. SAEW has 1.1-1.91 log reduction for aerobic bacteria. There was significant difference according to concentrations (p < 0.05). This study presents legitimacy for hygiene improvement of CCP by field verification. In addition, chemical disinfectants that can be mechanically applied have better reduction effects of high-pressure washing.