• Korean Chemical Engineering Research
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• v.53 no.3
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• pp.357-363
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• 2015

The development of the environment-friendly tire that meets the standard requirements according to tire labeling system can be improved through using highly homogeneous silica immobilized zinc oxide nanoparticles. In this study, a considerable amount of nanoporous silica was essentially added into nano zinc oxide to improve the physiochemical properties of the formed composite. The introduction of nanoporous silica materials in the composite facilitates the improvement of the wear-resistance and increases the elasticity of the tread. Therefore, the introduction of nanoporous silica can replace carbon black as filler in the formation of composites with desirable properties for conventional green tire. Herein, mesoporous silica immobilized zinc oxide nanoparticle with desirable properties for rubber compounds was investigated. Composites with homogeneous dispersion were obtained in the absence of dispersants. The dispersion stability was controlled through varying the molar ratio, ageing time and mixing order of the reactants. A superior dispersion was achieved in the sample obtained using 0.03 mol of zinc precursor as it had the smallest grain size (50.5 nm) and then immobilized in silica aged for 10 days. Moreover, the specific surface area of this sample was the highest ($649m^2/g$).

• Journal of Food Hygiene and Safety
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• v.29 no.1
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• pp.6-15
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• 2014

This study was performed to acquire the information on the foodborne pathogen risk management programs in a couple of developed countries by the expert meeting and searching the information on the web. The backgrounds, strategies and effects related to microbial hazards of the foodborne pathogen reduction programs in fresh produce (US), Escherichia coli O157:H7 in ground beef (US), Salmonella in chicken, pork and eggs (Denmark), and Vibrio parahaemolyticus in seafood (Japan) were investigated for case study. A comparison among the pathogen reduction programs was conducted to find advantages and disadvantages and implications of the policies to bring out implications of the programs. A model for foodborne pathogen reduction program was developed based on both the CODEX risk management scheme and the case studies as follows; 1) preliminary risk management activities, 2) planing a foodborne pathogen reduction program, 3) option identification and selection, 4) implementation (conducting the each stake-holders role and applying the intervention methods), 5) monitoring activities, 6) interim review, 7) continuation or amendment of implementation method by the interim review before achieving the goal, and 8) final review and additional cost-benefit analysis if necessary. This proposed model according to the role of the stake-holders can be used to conduct microbial risk management programs in Korea in the near future.

• Journal of agriculture & life science
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• v.50 no.3
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• pp.31-41
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• 2016

This study was conducted to develop a handy earth auger for use in sloppy and rugged forest terrains in order to reduce labor cost which comprises a major part of the production costs in forest afforestation projects. The first prototype is developed consist of two parts, the soil-digging screw and the battery power source. The specifications of the first prototype screw are: length of 170mm, a top diameter of 60mm, bottom diameter of 47mm, 23° angle for each helix, and a 50mm awl-head tip. The use of a single line of screw was selected for reduced weight. In addition, a power source of rotary DC Motor(WD-6G2425, WONILL, Korea) with a maximum torque of 30kgf-cm, rotation of 20-30rpm, K6G30C decelerator with a reduction ratio of 30:1 which could be used with no load for 48 was operated. In consideration of its weight, a lithium battery was utilized in line with the goal of developing a lightweight auger. In order to evaluate the performance of the first prototype, test sites were selected as 6 areas. The rotational force was found to be highest in area A(Solid area), followed by areas F(Mounted slope 40° area) and E(Mounted slope 30° area). It was also observed that in general, the rotational force increased along with the increase in soil depth with the maximum rotational force recorded at 10cm.

• Journal of Hospice and Palliative Care
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• v.9 no.1
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• pp.1-10
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• 2006

Purpose: Terminal cancer influences on patients as well as their family members. This research was performed to evaluate the quality of lift of primary family caregivers and to investigate the influencing factors. Methods: The results of survey were collected from 81 family caregivers who were taking care of hospitalized terminal cancer patients at an oncology department of university hospital in Daejeon from March 2005 to January 2006 with questionnaires. The questionnaires were consisted of the general characteristics of the subjects, and 36-items short-form Health Survey (SE-36) Korean version to evaluate the quality of life of family caregivers, the characteristics of patients and family caregivers' caring trait. Results: Family caregivers' mean (${\pm}SD$) SF-36 score was 47.9 (${\pm}20.7$). Influential factors on family caregivers' life quality were daily raring hours, economic burden, type of treatment; only supportive care, caring duration, sex, the numbers of ADLs (activity of daily livings) items that patients needed help in order by stepwised multiple logistic regression analysis (overall $R^2=0.639$, P=0.044). Conclusion: Daily raring hours and economic burden were two influential modifiable factors on family caregivers' quality of life. Therefore, social supportive systems are required to reduce family caregivers' daily caring hour and economic burden.

• The Korean Journal of Archival Studies
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• no.22
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• pp.115-155
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• 2009

As Korea was merged into Japan, the official documents during Kabo Reform and The Great Han Empire time were handed over to the Government-General of Chosun and reclassified from section based to ministry based. However they had been reclassified before many times. The footprints of reclassification can be found in the classification stamps and warehouse number stamps which remained on the cover of official documents from Kabo Reform to The Great Han Empire. They classified the documents by Section in the classification system of Ministry-Department-Section, stamped and numbered them. It is consistent with the official document classification system in The Great Han Empire, which shows the section based classification was maintained. Although they stamped by Section and numbered the documents, there were differences in sub classification system by Section. In the documents of Land Tax Section, many institutions can be found. The documents of the same year can be found in different group and documents of similar characteristics are classified in the same group. Customs Section and Other Tax Section seemed to number their documents according to the year of documents. However the year and the order of 'i-ro-ha(イロハ) song' does not match. From Kabo Reform to The Great Han Empire the documents were grouped by Section. However they did not have classification rules for the sub units of Section. Therefore, it is not clear if the document grouping of classification stamps can be understood as the original order of official document classification system of The Great Han Empire. However, given the grouping method reflects the document classification system, the sub section classification system of the Great Han Empire can be inferred through the grouping method. In this inference, it is understood that the classification system was divided into two such as 'Section - Counterpart Institution' and 'Section - Document Issuance Year'. The Government-General of Chosun took over the official documents of The Great Han Empire, stored them in the warehouse and marked them with Warehouse Number Stamps. Warehouse Number Stamp contained the Institution that grouped those documents and the documents were stored by warehouse. Although most of the documents on the shelves in each warehouse were arranged by classification stamp number, some of them were mixed and the order of shelves and that of documents did not match. Although they arranged the documents on the shelves and gave the symbols in the order of 'i-ro-ha(イロハ) song', these symbols were not given by the order of number. During the storage of the documents by the Government-General of Chosun, the classification system according to the classification stamps was affected. One characteristic that can be found in warehouse number stamps is that the preservation period on each document group lost the meaning. The preservation period id decided according to the historical and administrative value. However, the warehouse number stamps did not distinguish the documents according to the preservation period and put the documents with different preservation period on one shelf. As Japan merged Korea, The Great Han Empire did not consider the official documents of the Great Han Empire as administrative documents that should be disposed some time later. It considered them as materials to review the old which is necessary for the colonial governance. As the meaning of the documents has been changed from general administrative documents to the materials that they would need to govern the colony, they dealt with all the official documents of The Great Han Empire as the same object regardless of preservation period. The Government-General of Chosun destroyed the classification system of the Great Han Empire which was based on Section and the functions in the Section by reclassifying them according to Ministry when they reclassified the official documents during Kobo Reform and the Great Han Empire in order to utilize them to govern the colony.

• Korean Journal of Poultry Science
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• v.36 no.1
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• pp.15-21
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• 2009

A 10-wk layer feeding trial was conducted to investigate the effects of high quality corn distiller's dried grains with solubles (DDGS) on performance, egg qualities, and yolk fatty acid composition. The economics of using DDGS in the Korean situation was also analyzed. A total of 216 Hy-line Brown layers, 23-wk of age, were employed in this trial consisting of three dietary treatments (0%, 10%, and 20% DDGS), and six replicates per treatment. All experimental diets were prepared as iso-protein (17%) and iso-calorie (2,780 kcal/kg). The use of DDGS up to 20% in layer diets did not affect the feed intake, laying rate, egg weight, and feed conversion ratio (P>0.05). At 5th and 10th wk of the trial, the eggshell color, albumen height, and Haugh unit were not influenced by the DDGS supplementation. At 5th wk of the trial, the eggshell qualities, like eggshell weight, eggshell thickness, and eggshell strength, were not affected by the DDGS feeding; however, these eggshell qualities were decreased at 10th wk due to the 20% DDGS feeding (P<0.05). Yolk color of DDGS 20% increased compared to DDGS 0% at 5th and 10th wk of the trial (P<0.05). At 10th wk, yolk/egg ratio of DDGS 20% decreased compared to DDGS 0% (P<0.05). The yolk fat content was not changed due to DDGS feeding. The monounsaturated fatty acid content of yolk decreased linearly by feeding DDGS (P<0.05). The yolk polyunsaturated fatty acid content of DDGS 20% increased significantly compared to DDGS 0%. The DDGS feeding was not found to affect the degree of yolk fat unsaturation. The cost of feed (￦/kg feed) decreased as the level of DDGS increased. The production costs of egg (￦/kg egg) were cheap in the order of DDGS 10%, DDGS 20%, and DDGS 0%, indicating that DDGS is a viable alternative feed ingredient to corn and soybean meal. In conclusion, high quality DDGS ($L^*$ 61.72) could be used economically up to 20% level without any harmful effect on laying performance: however, the use of DDGS up to 10% is more economical than DDGS 20%.

• Radiation Oncology Journal
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• v.27 no.1
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• pp.35-41
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• 2009

Purpose: This study was designed to determine the optimum radiotherapy technique for internal mammary node (IMN) irradiation after breast-conserving surgery. Materials and Methods: We selected ten cases of early stage partial mastectomy for plan comparison. Five of the patients were treated to the right-side breast and the rest of the patients were treated to the left-side breast. For each case, four different treatment plans were made to irradiate the entire breast, IMNs and supraclavicular lymph nodes (SCLs). The four planning techniques include a standard tangential field (STF), wide tangential field (WTF), partially wide tangential field (PWT) and a photon-electron mixed field (PEM). We prescribed a dose of 50.4 Gy to the SCL field at a 3 cm depth and isocenter of the breast field. Results: The dose distribution showed clear characteristics depending on the technique used. All of the techniques covered the breast tissue well. IMN coverage was also good, except for the STF, which was not intended to cover IMNs. For the cases of the left-side breasts, the volume of the heart that received more than 30 Gy was larger (in order) for the WTF, PWT, PEM and STF. For radiation pneumonitis normal tissue complication probability (NTCP), the PWT showed the best results followed by the STF. Conclusion: Despite the variety of patient body shapes, the PWT technique showed the best results for coverage of IMNs and for reducing the lung and heart dose.

• Korean Journal of Organic Agriculture
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• v.17 no.2
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• pp.237-251
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• 2009

This study was carried out to evaluate the effect of replacing antibiotics by organic acid mixture on growth performances and blood metabolites in growing pigs. Twenty-five crossbred pigs (Large White${\times}$Landrace) at the age of 79 days were fed five different diets by supplementing organic acid mixture and chlortetracycline. The experimental diets were consisted of diets without antibiotics supplementation (control), diets added 100mg/kg of chlortetracycline to control diet (T1), diets added 100mg/kg of chlortetracycline and 0.1% of $Acidomix^{(R)}$ (comprising formic acid 25%, sorbic acid 10%, fumaric acid 10%) to control diet (T2), diets added 0.1% of $Acidomix^{(R)}$ to control diet (T3), and diets added 0.3% of $Acidomix^{(R)}$ to control diet (T4). The changes in feed conversion ratio, average daily gain and blood metabolites were investigated. Twenty-five pigs were allotted to five treatments with five replications of each and the experiment was conducted on the basis of complete randomized design for 6 weeks. Average daily gain was significantly (p<0.05) different between T4 and control diets. All treatments including diets added $Acidomix^{(R)}$ and chlortetracycline were slightly higher than control diets. The feed intakes did not show a significant difference between the control and other treatments, and did not give change in feed intake by the addition of $Acidomix^{(R)}$. No differences on feed conversion ratio among treatments were observed but T4 and T3 treatments showed lower value than other treatments. The concentrations of blood urea nitrogen, total cholesterol and triglyceride were significantly (p<0.05) different among treatments, but their values were within the normal range representing that effects on blood profile by organic acid or antibiotics supplementation were not found. The results from this study indicated that adding chlortetracycline or organic acid mixtures to diets showed tendency to improve average daily gain and feed conversion ratio in growing pigs. These results showed that antibiotics could be replaced by organic acid mixture in growing pig diets, leading to stimulated growth and improved feed conversion ratio.

• Journal of Nutrition and Health
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• v.9 no.2
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• pp.59-67
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• 1976

A series of experiment was carried out to study the effect of commonly used dietary fat or oils on the growth, feed efficiency, nutrient utilizability, nitrogen retention and serum cholesterol of rats and chicks fed various fat or oils at the level of 10% during 12 weeks of experimentation. Fat and oils used in this experiment were also analyzed for the composition of some fatty acids. The main observations made are as follows: 1. All groups received fat or oils gained more body weight than unsupplemented control group except chicks fed fish oil and rapeseed oil although no statistical significance was found between treatments. It was found that body weight gain achieved by the rats fed soybean oil, rapeseed oil, animal fat or corn oil was much greater than other group and that achieved by the chicks fed corn oil and animal fat was greater than other vegetable oil groups, although no statistical significance was found among treatments. 2. Feed intake data indicated that corn oil group of both rats and chicks consumed considerably more feed than other groups. Whereas feed intake of fish oil groups was the lowest among the experimental animals indicating that fish oil might contain unfavorable compound that depresses the palatability. In feed efficiency, soybean oil group of rats and corn oil group of chicks were significantly better than other experimental groups. In general, addition of fat or oils in the diet improved feed effeciency of diet. 3. Nutrient utiIizabiIity and nitrogen retention data showed that fat in the experimental diet containing 10% fat or oils was absorbed better than crude fat in control diet. It was also found that there was no significant difference in nitrogen retention among treatment. 4. Liver fat content of rapeseed oil group was much higher than that of control group and other group. It was also noticed that feeding more polyunsaturated fatty acids resulted in higher content of Iiver fat. 5. Present data indicated that serum cholesterol content of rapeseed oil and sesame oil group of rat was the higher than that of control group. Serum cholesterol content of animal fat group of chicks was higher than other group. It was interesting to note that serum cholesterol content of chicken was higher than that of rats?regardless of the kind of oils received. 6. Analytical data revealed that fatty acid composition of vegetable oil was composed mainly of oleic acid and linoleic acid, whereas animal fat and fish oil were composed of saturated fatty acid such as, myristic and palmitic acid. It should be mentionted that the perilla oil contained a very large amount of linolenic acid (58.4%) comparing with that in order vegetable oils. Little arachidonic acid was detected in vegetable oil, whereas none in animal fat and. fish oil.

• Restorative Dentistry and Endodontics
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• v.36 no.4
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• pp.280-289
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• 2011

Objectives: The purpose of this study was to evaluate ${\mu}TBS$ (microtensile bond strength) of current dentin bonding adhesives which have different hydrophobicity with low-shrinkage silorane resin. Materials and Methods: Thirty-six human third molars were used. Middle dentin was exposed. The teeth were randomly assigned to nine experimental groups: Silorane self-etch adhesives (SS), SS + phosphoric acid etching (SS + pa), Adper easy bond (AE), AE + Silorane system bonding (AE + SSb), Clearfil SE bond (CSE), CSE + SSb, All-Bond 2 (AB2), AB2 + SSb, All-Bond 3 (AB3). After adhesive's were applied, the clinical crowns were restored with Filtek LS (3M ESPE). The 0.8 mm ${\times}$ 0.8 mm sticks were submitted to a tensile load using a Micro Tensile Tester (Bisco Inc.). Water sorption was measured to estimate hydrophobicity adhesives. Results: ${\mu}TBS$ of silorane resin to 5 adhesives: SS, 23.2 MPa; CSE, 19.4 MPa; AB3, 30.3 MPa; AB2 and AE, no bond. Additional layering of SSb: CSE + SSb, 26.2 MPa; AB2 + SSb, 33.9 MPa; AE + SSb, no bond. High value of ${\mu}TBS$ was related to cohesive failure. SS showed the lowest water sorption. AE showed the highest solubility. Conclusions: The hydrophobicity of adhesive increased, and silorane resin bond-strength was also increased. Additional hydrophobic adhesive layer did not increase the bond-strength to silorane resin except AB2 + SSb. All-Bond 3 showed similar ${\mu}TBS$ & water sorption with SS. By these facts, we could reach a conclusion that All-Bond 3 is a competitive adhesive which can replace the Silorane adhesive system.