• Food Engineering Progress
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• v.23 no.3
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• pp.193-199
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• 2019

This study aimed to investigate the impact of protease treatments on the yield of rice starch (RST) from frozen rice flours, and to compare the physicochemical properties of RST by alkaline steeping (control) and enzymatic isolation (E-RST) methods. Although the yield of E-RST, prepared according to conditions designed by the modified 23 complete factorial design, was lower than the control, the opposite trends were observed in its purity. E-RST (RST1, isolated for 8 h at 15℃ with 0.5% protease; RST2, isolated for 24 h at 15℃ with 1.5% protease; RST3, isolated for 24 h at 15℃ with 0.5% protease) with the yields above 50% were selected. Amylose contents did not significantly differ for the control and RST2. Relative to the control, solubilities were higher for all E-RST, but swelling power did not significantly differ for E-RST except for RST1. Although all E-RST revealed higher gelatinization temperatures than the control, the reversed trends were found in the gelatinization enthalpy. The pasting viscosities of all E-RST were lower than those of the control. Consequently, the enzymatic isolation method using protease would be a more time-saving and eco-friendly way of preparing RST than the alkaline steeping method, even though its characteristics are different.

• Korean Journal of Psychosomatic Medicine
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• v.29 no.1
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• pp.17-25
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• 2021

Objectives : This study aimed to investigate quality of life, severity of depression, suicidality, subjective health and subjective stress of depression with subjective cognitive decline in Korean adults. Methods : We used the 7th KNHANES data to enroll 415 participants with a score of 10 or higher on Patient Health Questionnaire-9 (PHQ-9), aged 20-64. Depression was divided into two groups based on the presence/absence of subjective cognitive decline. Demographic and psychological characteristics were compared between two groups. Correlation analysis of subjective cognitive decline, quality of life, depression, suicidal idea was carried out. To detect which variables influenced quality of life, a multiple regression analysis was carried out. Results : Among the 415 participants, 98 had depression with subjective cognitive decline. We identified significant differences in age, marital status, education, employment between the two groups. After adjusting for these variables, depression with subjective cognitive decline had lower EuroQol-5D index scores, more severe depressive symptoms without cognition and worse subjective health than depression without cognitive decline. There was a significant correlation between subjective cognitive decline and quality of life (r=-0.236, p<0.001), suicidal idea (r=0.182, p<0.001), depression score without cognition (r=0.108, p=0.028). Through multiple regression analysis, subjective cognitive decline was predictor of reduced quality of life (β=-0.178, p<0.001). Conclusions : Depression with subjective cognitive decline has poor quality of life and severe depression. Cognitive decline should be considered to improve treatment result in depression.

• The Journal of Sustainable Design and Educational Environment Research
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• v.20 no.2
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• pp.1-10
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• 2021

The results of research and analysis are as follows: First, there were 108 types of change patterns in the number of elementary school students. Second, based on the similarity of 108 types of change patterns in the number of students, a type system diagram was presented. Third, in the case of a total of 18 types of change patterns in the number of students, the number of students decreased significantly due to the establishment of additional schools on top of the existing schools. The result of a a long-term survey and analysis on the trend of increase and decrease in the number of students across the country shows an urgent need todevelop policy tasks across the entire school accommodation plan, such as the establishment of differentiated schools suitable for regional characteristics, relocation, consolidation, reorganization of school districts, remodeling, and appropriatization projects.

• Applied Chemistry for Engineering
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• v.32 no.1
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• pp.117-123
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• 2021

In this study, the composite was prepared by mixing SiOx, soft carbon, and carbon black and the electrochemical properties of lithium ion battery were investigated. The content of SiOx added to improve the capacity of the soft carbon anode material was varied to 0, 6, 8, 10, 20 wt%, and carbon black was added as a structural stabilizer for reducing the volume expansion of SiOx. The physical properties of prepared CB/SiOx/C composite were investigated through XRD, SEM, EDS and powder resistance analysis. In addition, the electrochemical properties of prepared composite were observed through the charge/discharge capacity, rate and impedance analysis of the lithium ion battery. The prepared CB/SiOx/C composite had an inner cavity capable of mitigating the volume expansion of SiOx by adding carbon black. The formed internal cavity showed a low initial efficiency when the SiOx content was less than 8 wt%, and low cycle stability when the content of SiOx was less than 20 wt%. The CB/SiOx/C composite containing 10 wt% of SiOx showed an initial discharge capacity of 537 mAh/g, a capacity retention rate of 88%, and a rate of 79 at 2C/0.1C. SiOx was added to improve the capacity of the soft carbon anode material, and carbon black was added as a structural stabilizer to buffer the volume change of SiOx. In order to use the CB/SiOx/C composite as a high-efficiency anode material, the mechanism of the optimal SiOx and the use of carbon black as a structural stabilizer was discussed.

• Journal of the Korean Institute of Gas
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• v.24 no.6
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• pp.1-10
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• 2020

Reactivity controlled compression ignition (RCCI) combustion is one of dual-fuel combustion systems which can be constructed by early diesel injection during the compression stroke to improve premixing between diesel and air. As a result, RCCI combustion promises low nitrogen oxides (NOx) and smoke emissions comparing to those of general dual-fuel combustion. For this combustion system, to meet the intensified emission regulations without emission after-treatment systems, exhaust gas recirculation (EGR) is necessary to reduce combustion temperature with lean premixed mixture condition. However, since EGR is supplied from the front of turbocharger system, intake pressure and the amount of fresh air supplementation are decreased as increasing EGR rate. For this reason, the effect of various EGR rates on the brake power and thermal efficiency of natural gas/diesel RCCI combustion under two different operating conditions in a 6 L compression ignition engine. Varying EGR rate would influence on the combustion characteristic and boosting condition simultaneously. For the 1,200/29 kW and 1,800 rpm/(lower than) 90 kW conditions, NOx and smoke emissions were controlled lower than the emission regulation of 'Tier-4 final' and the maximum in-cylinder pressure was 160 bar for the indurance of engine system. The results showed that under 1,200 rpm/29 kW condition, there were no changes in brake power and thermal efficiency. On the other hand, under 1,800 rpm condition, brake power and thermal efficieny were decreased from 90 to 65 kW and from 37 to 33 % respectively, because of deceasing intake pressure (from 2.3 to 1.8 bar). Therefore, it is better to supply EGR from the rear of compressor, i.e. low pressure EGR (LP-EGR) system, comparing to high pressure EGR (HP-EGR) for the improvement of RCCI power and thermal efficiency.

• Journal of agriculture & life science
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• v.53 no.4
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• pp.77-92
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• 2019

The purpose of this study was to investigate the carcass characteristics and the primal cut yields from carcasses according to the sex of Hanwoo. Experimental animals comprised of 80 cows, 29 bulls, and 71 steers. After slaughtering, they were evaluated to estimate the productivity of carcass components by market weight, and to predict the beef carcass yield. The average of fasting weight of cow, bull and steer were 634.75 kg, 721.86 kg, and 754.10 kg respectively. Market weight of Hanwoo at cold carcass weight, primal lean cut weight, sub-primal lean cut weight, bone weight and fat weight were 381.01~467.60 kg, 240.79~310.36 kg, 208.27~276.47 kg, 57.23~76.28 kg and 89.19~138.97 kg respectively. Body measurement traits had side length, hindquarter length, cervical vertebrae length, lumbar vertebrae length, sacral vertebrae length, 6th lumbar vertebrae~heel length, 5~6th thoracic vertebrae breadth, 4~5th lumbar vertebrae breadth, 5th sacral vertebrae breadth, 7~8th thoracic vertebrae girth and 7~8th thoracic vertebrae thick were highest length in steer. Carcass weight (CW) were significantly (p<0.05) affected by sex and live weight. The lean meat percentage, fat percentage and bone percentage based on the weight of cold carcasses were significantly different (p<0.05) between sex groups. The primal cuts rate for deungsim, moksim, abdari, udun, suldo, yangjee and satae were higher in bulls than those of the caws and steers. The carcass by-product weight rate in steer had lower oxtail and rib cartilage than cow and bull, while cow showed lower beef leg bones and jappyeo than bull steer (p<0.05). Body measurement traits was always important for primal cut weight estimates.

• Journal of agriculture & life science
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• v.53 no.5
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• pp.127-136
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• 2019

Today, as the specification of pigs increases, it is important to develop eco-friendly livestock feeds that do not add antibiotics to highly utilizable materials as feed resources, and to produce functional eco-friendly pork and processed products. The purpose of this study was to establish Rubus occidentalis (RO) byproducts containing various amounts of physiologically active substances such as anticancer, anti - inflammation and antioxidant as a raw material for pig feed. The multifaceted efficacy of the RO fermented fodder (ROFF) was confirmed by the nutrient transport factors and antioxidant activity of Berkshire pigs. ROFF was added 0.3% to the general diet and the efficacy was confirmed by feeding diets to Berkshire pigs according to each weight for 43~73 days. As a result, the total cholesterol (TC), LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C) levels were decreased or were increased in the castrated male and female Berkshire pigs but not significantly. It was confirmed that the tendency was improved in nutrition physiology. The biochemical levels of female finishing pigs were not significant but increased. In the case of finishing pigs with possibility of pregnancy, it is expected that the nutrition supply for piglet production and will help in the production of the healthy piglet. Transferrin (TFE) levels tended to increase in female growing pig and 110-150 kg finishing pigs. Thus ROFF could minimize the negative effects of iron contents deficiency in female Berkshire pigs. Glutathione peroxidase 1 (GPx1) activity was increased in castrated male and female 110-150 kg finishing pigs. Therefore, ROFF tends to improve the antioxidant capacity. The results of this study suggest that ROFF is one of the most favorable dietary sources when considering the contents of RO in feed. In particular, ROFF could have a positive effect on nutrient transport and iron content of female rather than castrated male Berkshire pigs.

• Korean Journal of Poultry Science
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• v.47 no.4
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• pp.211-217
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• 2020

This study evaluated calcium hydroxide (slaked lime) and a combination of plant extracts ('natural product'; clove, cinnamon, and saponin; 1:1:1 ratio) as acaricidal control mechanisms for poultry red mites. Red mite susceptibility was evaluated after treatments with 10% slaked lime, 20% slaked lime, and 1% natural product. The duration of the acaricidal effect was also tested at 0, 10, 30, and 60 min after treatment using 20% slaked lime, 1% natural product, or a mixture of both. In the in vitro experiment, the slaked lime treatments were 73.2% (10% slaked lime) and 85.1% (20% slaked lime) effective on red mites. In acaricidal effect of control materials over times, with 20% slaked lime, the acaricidal effect decreased to 50.7% after 30 min, and 12.7% after 60 min (P<0.05). With 1% natural product, there was no acaricidal effect after 30 min (P<0.05). With 20% slaked lime +1% natural product, all of poultry red mites died until 30 min, and 92.9% after 60 min (P<0.05). On the farm, poultry red mites were observed that the number of poultry red mites increased 7,923 from 36 to 45 weeks, but then decreased to 483 after 20% slaked lime plus 1% natural product treatment. These results indicate that combining slaked lime and plant extracts effectively control poultry red mites.

• The Journal of Sustainable Design and Educational Environment Research
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• v.20 no.1
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• pp.43-54
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• 2021

The results of the research and analysis are as follows: First, from the existing 57 types, 51 types were additionally discovered through the Gyeonggi-do research and analysis, and a total of 108 types could be subdivided. Second, as a result of the survey and analysis of Gyeonggi-do, 17 new unique types and the causes were found Third, out of 7 less than 10 years old schools, the Ns1 and Ns2 types were accounting for almost all of them. Of the 19 mid-term new schools, the Nm7 type accounted for 32.3%, and of the 41 long-term new schools, the most occupied type was Nl13 (33.5%). Among the 20 long-term rising types of 20 to 30 years old schools, the Ai19 type accounted for 22.6%, and the Ai8 type accounted for 19.4%. Among the 21 long-term decline types in existing schools, 17.0% was for the Ad5 type, 16.1% for the Ad15 type, 15.2% for the Ad10 type, 10.0% for the Ad7 type, and 8.1% for the Ad8 type.

• Korean Journal of Poultry Science
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• v.48 no.1
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• pp.13-22
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• 2021

The present experiment was conducted to evaluate the effect of stocking density on the growth performance, immune status, and meat quality of broilers. In total, 385 one-day-old Ross 308 broilers were randomly assigned to one of four distinct stocking densities: 26 birds/㎡, 22 birds/㎡, 19 birds/㎡, and 16 birds/㎡. They were fed the diet ad libitum for 5 weeks. Immunoglobulin (Ig) and corticosterone levels were evaluated, and growth performance, blood parameters, and breast meat quality were determined. It was observed that the weight gain and feed intake of growers (21~35 d) and broilers (0~35 d) were significantly reduced as the stocking density increased (P<0.05). However, the feed intake of starters (0~21 d) significantly increased as the stocking density increased (P<0.05). There were no significant differences in the biochemical profiles among the four different stock densities. Furthermore, no significant differences were observed in the stress parameters: (heterophils / lymphocytes ratio and corticosterone), IgA, and IgM; however, IgG significantly increased with stocking density (P<0.05). The pH, water holding capacity, and cooking loss of the muscle were all unaffected by the stocking density, but the shear force (tenderness) increased slightly as the density increased. The findings of this study suggest that a lower stocking density (16 birds/㎡) significantly improved the shear force of breast meat and IgG in broilers.