• Korean Journal of Poultry Science
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• v.47 no.3
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• pp.121-126
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• 2020

This study was conducted to investigate the effect of drinking ion water on the performance, egg quality, and serum biochemical properties of laying hens in a high-temperature environment. A total of 180 laying hens with equal egg production rates were randomly divided into three treatments with five replicates. Treatments were applied from 24 to 27 weeks of age and included the supply of ion water (IW), tap water (TW), and cold water (CW). The results showed that the egg production rate, egg weight, and feed intake of hens were significantly (P<0.01) improved in the IW group compared with those in the TW group but did not differ from those in the CW group. Egg quality parameters such as albumen height, Haugh unit, and eggshell thickness were found to be higher in the IW than in the TW group (P<0.05); however, no significant differences were observed in comparison with the CW group. Serum Ca and P concentrations tended to increase (P<0.10) in the IW group, and serum high-density lipoprotein cholesterol and albumin levels were greater (P<0.05) in response to IW than those to TW. This study provides evidence that the supply of IW can relieve the high-temperature stress during the summer. In particular, because the improved effects of the IW were confirmed to be similar to those of CW, it shows potential as a method to manage the drinking water of hens in the summer season along with the supply of CW.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.5
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• pp.469-474
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• 2000

This study was conducted to investigate the utilization of defatted soybean meal as a substitute for fish meal in the diet for juvenile flounder (Paralichthys olivaceus). Duplicate groups of average weighing 35 g were fed one of four isonitrogenous ($54{\%}$) and isocaloric (575 kcal/100 g diet) diets containing $0{\%}, 10{\%}, 20{\%} and 30{\%}$ soybean meal for 45 days. Survival rates of all groups were $100{\%}$, Weight gain of fish decreased with increasing dietary soybean meal levels, However, this value was not significantly different between fish fed the control and $10{\%}$ soybean meal diet (P > 0.05). Feed efficiency and protein efficiency ratio decreased with increasing dietary soybean meal levels, but no significant differences were found among fish fed the control, $10{\%}\;and\;20{\%}$ soybean meal diets (P > 0.05). Daily feed and protein intake increased with increasing dietary soybean meal level. Crude protein and moisture content of liver tended to decrease and crude lipid content tended to increase with decreasing of dietary soybean meal levels. Plasma total cholesterol levels of fish fed the diets containing $20{\%}\;and\;30{\%}$ soybean meal were significantly lower than that of fish fed control diet (P < 0.05), Plasma GOT level significantly increased with increasing dietary soybean meal level (P < 0.05). It is concluded that soybean meal can be used as a partial substitute for fish meal up to $10{\%}$ in this dietary formulation for growth of juvenile flounder.

• Korean Journal of Agricultural and Forest Meteorology
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• v.1 no.1
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• pp.29-35
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• 1999

Soil structure and organic matter have been known to strongly affect water flow and solute transport, yet little information is available concerning soil hydraulic properties related to soil physical and chemical properties in the forest site. The purpose of this study was to quantify the spatial variability and spatial correlation of the measured parameter values from the plots established with the rainfall simulator on Japanese larch(Larix leptolepis) dominated site in Kwangju. Kyunggi-Do. Measurement of soil water flux and retention were made with the inherent soil texture, soil structure, and organic matter. The method was based on the observation that when water was applied at a constant rate to the soil surface on each plot. The method was simple to apply and consists of following steps: (i) Wet the soil from a rainfall simulator with several known discharge rates on a relatively leveled soil surface with and without organic matter. (ii) Once the borders of the ponded zone were steady, saturated hydraulic conductivity( $K_{s}$) and the matric flux function(F) was evaluated from a regression of flux vs. the reciprocal of the ponded area. A conductivity of the form $K_{i+}$$_1$ $_{c}$= $K_{i}$( $_{c}$) [1-d /dz] where flux continuity implies. For this, continuity of matric potential at the interface at all times are as follows: $_1$( $Z_{c}$) = $_2$( $Z_{c}$) = $_{c}$ for steady state intake from water ponded on the soil surface. Results of this investigation showed the importance of understanding spatial variability in wide differences of water retention and saturated hydraulic conductivity with respect to pore geometry and organic matter contents which influenced the water flux throughout the soil profile.l profile.ile.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.5
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• pp.455-461
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• 2015

A high-pressure fuel pump is a key component in a gasoline direct injection (GDI) engine; thus, understanding its flow characteristics is essential for improving the engine power and fuel efficiency. In this study, AMESim, which is a hydraulic analysis program, was used to analyze the performance of the high-pressure fuel pump. However, since AMESim uses a one-dimensional model for the system analysis, it does not accurately analyze the complicated flow characteristics. Thus, Fluent, computational fluid dynamics (CFD) software, was used to calculate the flow rates and net forces at the intake and discharge ports of the high-pressure fuel pump where turbulent flow occurs. The CFD analysis results for various pressure conditions and valve lifts were used as look-up tables for the AMEsim model. The CFD analysis results complemented the AMEsim results, and thus, improved the accuracy of the performance analysis results for the high-pressure fuel pump.

• Journal of Aquaculture
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• v.18 no.2
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• pp.98-106
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• 2005

A feeding trial of two extruded pellets (EPI, 45% crude protein with 7% crude lipid and EP2, 47% crude protein with 10% crude lipid)${\times}$ two satiation rates (satiation and 80% satiation)${\times}$ three feeding frequencies (three, two and one meal a day) factorial design with three replications was carried out to investigate the optimum feeding frequency and satiation rate for growth of juvenile flounder. Flounder averaging 55 g were fed a extruded pellets for 58 days. Daily feed intake was affected by dietary composition, feeding frequency and satiation rate (P<0.05). Weight gain of fish fed the EP1 and EP2 was not affected by both dietary composition and feeding frequency (P>0.05), but affected by feeding satiation rate (P<0.05). Weight gain of fish fed the each of EP1 and EP2 twice daily with satiation was the highest among treatments, but was not significantly different to that of fish fed the diets three times daily with satiation feeding. Feed efficiency and protein efficiency ratio of the fish were not affected by dietary composition, feeding frequency and satiation rate (P>0.05). Moisture, crude protein and crude lipid contents of the muscle of fish were affected by satiation rate. Moisture and crude protein contents of the liver were affected by dietary composition. Based on fish performance results, it can be concluded that the proper feeding frequency for the growth of juvenile flounder grown from 55 g to 90 g is two meals a day with satiation feeding, regardless of dietary composition used in this study.

• Journal of Preventive Medicine and Public Health
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• v.40 no.4
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• pp.305-312
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• 2007

Objectives : To estimate the awareness, treatment and control rate, as well as to identify the awareness-related factors for hypertension. Methods : The study participants were 482 adults (men 206, women 276), aged 45 or over, diagnosed with hypertension and living in Chuncheon. The awareness rate was defined as the proportion of persons among those with hypertension who had previously been diagnosed by a physician. The treatment rate was defined as the proportion of persons who had used anti-hypertensive medication, among those who were aware of their hypertension. The control rate was defined as the proportion of persons who kept blood pressure normal, among those who had been treated for their hypertension. Multivariable logistic regression analysis was carried out for the awareness-related factors using SAS VER 8.1. Results : The awareness, treatment, and control rate were 55,8% (53.4% for men; 57.6% for women), 89.6% (87,2% for men; 91.2% for women), and 34.4% (28.1 % for men; 38.6% for women), respectively. The awareness-related factors included a family history of hypertension (odds ratio[OR], 5.63; 95% confidence interval[95% CI]=1.53-20.72), smoking([Ex; OR 0.38, 95% CI= 0.15-0.96)], [Current; OR 0.28, 95% CI=0.10-0.80]), and alcohol intake ([Ex; OR 3.22, 95% CI 1.03-10.09],[Current; OR 3.36, 95% CI=1.30-8.71]) for men, and education(OR 2.23, 95% CI=1.10-4.53), body mass index(OR 2.72, 95% CI=1.13-6.53), and self-rated health(OR 2.38, 95% CI=1.07-5.30) for women. Conclusions : The awareness rate of hypertension among the middle aged and elderly in Chuncheon was 55.8%. The related factors of awareness were gender specific. Further studies are needed to elucidate the putative reasons for these gender differences.

• Korean Journal of Environmental Agriculture
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• v.30 no.4
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• pp.440-445
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• 2011

BACKGROUND: This study was conducted to monitor the current status of pesticide residues and to assess their risk in domestic agricultural products. The samples were rice, barley, lettuce and perilla leaf. These four types of agricultural products were those with GAP(Good Agricultural Practice) certification, organic agricultural products, pesticide-free agricultural products or general agricultural products. METHODS AND RESULTS: They were purchased from traditional markets and supermarkets of 12 regions in Korea from July to August 2010. The total number of samples was 259 for agricultural products and these were analyzed by GC/ECD, GC/NPD and GC/MSD. We used multiresidue methods to analyze for 110 different pesticides except for herbicides. CONCLUSION: In this study, residual pesticides were detected in 18 samples. Among these general agricultural products, organic agricultural products and products with GAP-certification were detected in 12, 4 and 2 samples, respectively. Detection rates of general agricultural products, organic agricultural products and products with GAPcertification were 4.6%, 1.5% and 0.8% respectively. Pesticides were not detected in pesticide-free agricultural products. Their detection levels were less than their maximum residue levels. Their estimated daily intakes ranged from 0.0003% to 0.04302% of their acceptable daily intakes, of which the values have no effect on human health.

• Korean Journal of Poultry Science
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• v.20 no.4
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• pp.217-231
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• 1993

Due to the increased awareness on the relationship between high cholesterol intake and cardiovascular disease, the development of low cholesterol eggs and egg products are necessary at the present time. Largely, two approaches are possible to develop low cholesterol eggs. The first approach is the production of low cholesterol eggs by altering feeds of layers, by administering drugs, by genetic selection of strains and breeds, and by management of laying cycle, age and egg size. The second approach is to manufacture low cholesterol eggs technically treated with adsorbant, solvent, enzyme, edible oil and supercritical fluid. Both approaches have their own pros and cons, respectively, as far as the cholesterol removal rates, the easeness of process, and the economic reasons are concerned. The low cholesterol egg production is quite labor-intensive and has relatively low cholesterol removal rate(30∼50％ ) compared to that of chemically treated eggs. On the other hand, the low cholesterol eggs treated with chemicals have a very high cholesterol removal rate (80∼90％) but some of the methods are not completely safe as food processing purposes due to the residual chemicals and the sensory quality is not as good as the low cholesterol eggs without chemical treatment. Therefore, further studies must be conducted to improve the sensory quality of low cholesterol eggs and to eliminate fear about the harmfulness using low cholesterol eggs.

• Journal of Food Hygiene and Safety
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• v.32 no.2
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• pp.101-106
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• 2017

Based on the previous reports that majority of teachers have negative perceptions on food additives, a teacher training program called 'Let's teach food additives correctly' was developed and applied to improve teachers' unbalanced perception on food additives and let them teach students with sound scientific background. The 15-hours training program consisted of understanding of food safety and food additives, education materials on food additives, development of teaching-learning plan, meeting with professionals from Ministry of Food and Drug Safety (MFDS), visiting MFDS labs, application to school class, and evaluation. A total of 63 teachers participated in the training through 2 sessions conducted in August 2016. As a result, teachers showed high satisfaction rates (4.2~4.5 in 5.0-Likert scale) and 91.5% answered the training helpful for the school class. Although their initial intention to participate the training was to know the details of negative intake effects of food additives, their such perception was totally changed in addition, they suggested a continuous training for teachers and immediate correction of incorrect information in school textbooks. Also, post-training education for 1,172 students by these teachers appeared to improve the understanding of and the native perceptions on food additives significantly (p < 0.001). Above results showed that the training program could solve the problem of transmitting unbalanced information on food additives to students by training teachers, and such channel could be used to facilitate food-related risk communication.

• Food Science of Animal Resources
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• v.28 no.4
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• pp.451-456
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• 2008

This study was conducted to determine the effects of dietary supplementation with conjugated linoleic acid (CLA) feeding levels (0, 0.5, 1.0, 1.5, and 2.0%) on the carcass characteristics, growth performance, serum cholesterol, and fatty acid in thigh of chicken meat. Two hundred broiler (Arbor Acre Broiler, male) were randomly assigned to five groups and were fed for five weeks and slaughtered. Thigh muscle was used for determining fatty acid composition. There was no significant difference in growth performance, such as weight gain, feed intake and feed conversion by CLA levels. Among carcass characteristics, percentage of carcass, thigh, breast, and drumstick was not influenced by the dietary CLA levels, but abdominal fat was significantly reduced with the increased CLA amount in the broilers diets (p<0.05). Higher CLA levels increased HDL-C and reduced total cholesterol and LDL-C (p<0.05). As the dietary CLA levels increased, muscular palmitic acid (saturated fatty acid) levels was increased, but the rates of oleic acid, linoleic acid, and arachidonic acid (unsaturated fatty acid) were decreased. In addition. CLA isomers were linearly increased with the increase in dietary CLA levels (p<0.05). As a conclusion, 2% of CLA feeding is possible to maximize accumulation of CLA in meat, but changes in fatty acid composition is not profitable. Therefore, 1% of CLA feeding i,j considered to be proper for accumulation of CLA and minimization of the change in fatty acid.