• Resources Recycling
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• v.28 no.4
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• pp.44-50
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• 2019

In the electric arc furnace process, the chemical energy such as the heat of oxidation reaction and the heat of carbon combustion etc. is consumed as 30% of the total input energy. In order to reduce $CO_2$ emission in EAF, it is necessary to decrease the use of electric power energy during scrap melting stage and increase the use of chemical energy. In general, when the carbon materials is individually charged into the molten steel, the carbon materials floated to the slag layer due to low density before it is dissolved in molten steel. When the concentration of carbon in the molten steel is high, the combustion energy of carbon by oxygen injection can lower the electric power energy and improve the chemical energy consumption. Therefore, an efficient charging methods of carbon material is required to increase the efficiency of carbon combustion heat. On the other hand, Al-dross, which is known as a by-product after Al smelting, includes over 25 mass% of metallic Al, and the oxidation heats of Al is lager than that of carbon. However, the recycling ratio fo Al-dross was very low and is almost landfilled. In order to effectively utilize the heats of oxidation of Al in Al-dross, it is necessary to study the application of Al-dross in the steel process. In this study, the dissolution efficiency of carbon and aluminum in molten steel was investigated by varying the reaction temperature and the mixing ratios of coke and Al-dross.

• Animal Bioscience
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• v.34 no.4
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• pp.662-669
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• 2021

Objective: Effects of linseed oil (LO) supplementation on the fat content and fatty acid profile of breast meat, and the expression of three genes in the liver, breast muscle and fat tissues of commercial 154-day-old hybrid male turkeys were investigated. Methods: The animals in the control group were fed a commercially available feed and received no LO supplementation (n = 70), whereas animals in the LO group (n = 70) were fed the same basic diet supplemented with LO (day 15 to 21, 0.5%; day 22 to 112, 1%). The effect of dietary LO supplementation on fatty acid composition of breast muscle was examined by gas chromatography, and the expression of fatty acid desaturase 2 (FADS2), peroxisome proliferator activated receptor gamma (PPARγ), and insulin-like growth factor 1 (IGF1) genes was analysed by means of quantitative reverse transcription polymerase chain reaction. Results: The LO supplementation affected the fatty acid composition of breast muscle. Hepatic FADS2 levels were considerably lower (p<0.001), while adipose tissue expression was higher (p<0.05) in the control compared to the LO group. The PPARγ expression was lower (p<0.05), whereas IGF1 was higher (p<0.05) in the fat of control animals. There were no significant (p>0.05) differences in FADS2, PPARγ, and IGF1 gene expressions of breast muscle; however, omega-6/omega-3 ratio of breast muscle substantially decreased (p<0.001) in the LO group compared to control. Conclusion: Fatty acid composition of breast meat was positively influenced by LO supplementation without deterioration of fattening parameters. Remarkably, increased FADS2 expression in the liver of LO supplemented animals was associated with a significantly decreased omega-6/omega-3 ratio, providing a potentially healthier meat product for human consumption. Increased PPARγ expression in fat tissue of the LO group was not associated with fat content of muscle, whereas a decreased IGF1 expression in fat tissue was associated with a trend of decreasing fat content in muscle of the experimental LO group.

• Animal Bioscience
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• v.34 no.7
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• pp.1202-1209
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• 2021

Objective: The intestinal microbiota plays an important role in host physiology, metabolism, immunity, and behavior. And host genetics could influence the gut microbiota of hybrid animals. The three-way cross model is commonly utilized in commercial pig production; however, the use of this model to analyse the gut microbial composition is rarely reported. Methods: Two three-way hybrid pigs were selected, with Saba pigs as the starting maternal pig: Duroc× (Berkshire×Saba) (DBS) pig, Berkshire×(Duroc×Saba) (BDS) pig. One hundred pigs of each model were reared from 35 days (d) to 210 d. The body weight or feed consumption of all pigs were recorded and their feed/gain (F/G) ratio was calculated. On day 210, 10 pigs from each three-way cross were selected for slaughter, and cecal chyme samples were collected for 16S rRNA gene sequencing. Results: The final body weight (FBW) and average daily gain (ADG) of DBS pigs were significantly higher than those of BDS pigs (p<0.05), while the F/G ratios of DBS pigs were significantly lower than those of BDS pigs (p<0.05). The dominant phyla in DBS and BDS pigs were Bacteroidetes (55.23% vs 59%, respectively) and Firmicutes (36.65% vs 34.86%, respectively) (p>0.05). At the genus level, the abundance of Prevotella, Roseburia, and Anaerovibrio in DBS pigs was significantly lower than in BDS pigs (p<0.01). The abundance of Eubacterium, Clostridium XI, Bacteroides, Methanomassiliicoccus, and Parabacteroides in DBS pigs was significantly higher than in BDS pigs (p<0.05). The FBWs and ADGs were positively correlated with Bacteroides, ClostridiumXI, and Parabacteroides but negatively correlated with the Prevotella, Prevotella/Bacteroides (P/B) ratio, Roseburia, and Anaerovibrio. Conclusion: These results indicated that host genetics affect the cecal microbiota composition and the porcine gut microbiota is associated with growth performance, thereby suggesting that gut microbiota composition may be a useful biomarker in porcine genetics and breeding.

• Journal of Mushroom
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• v.18 no.4
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• pp.311-316
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• 2020

The effect of the nitrogen content of sawdust medium (1.2~1.8%) and the restriction stage temperature (2, 4, and 6℃) on the growth and storage characteristics of Flammulina velutipes (winter mushroom) were investigated. With increased nitrogen content, the growth days shortened and the yield of the fruiting body increased. The effect of restriction temperature on the growth of the fruiting body differed depending on the nitrogen content. No difference in restriction temperature was evident for T1 with a low nitrogen content of 1.28%. In medium with a nitrogen content ≥1.55%, the yield and length of the pileus and stipe increased as the restriction temperature decreased. The weight loss ratio according to the storage period did not change according to the nitrogen content in the medium. A low weight loss ratio of 1.50 to 1.93% was observed at a restriction temperature <4℃. When T3 with high nitrogen content in the medium was treated at a restriction temperature of 4℃, the fruiting body color values after 31 days of storage were 84.81 (L) and 6.3 (ΔE). This color change was minute compared to that after other treatments. The sensory characteristics score was 5.2 after 31 days of storage, and the quality remained acceptable for consumption.

• Journal of Nutrition and Health
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• v.54 no.6
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• pp.631-643
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• 2021

Purpose: Frailty is a clinical syndrome in older adults, and adequate nutrition is a modifiable factor in preventing the condition. The current study aims to investigate the association between frailty and dietary intake in the Korean elderly. Methods: This cross-sectional study included data from the 2018 Korean National Health and Nutrition Examination Survey of 1,268 subjects (535 men and 733 women) aged 65 years or older. Frailty was defined as having more than three of the following 5 modified Fried frailty phenotype criteria: unintentional weight loss, exhaustion, walking difficulties, weakness, and low physical activity. Dietary intake was assessed by applying the one-day 24-hour dietary recall. The association between frailty and dietary intakes were analyzed by multiple logistic regression. Results: Totally, 9.7% men and 21.9% women were classified as the frail group. Increasing levels of frailty were proportional to a decreased mean nutrient adequacy ratio in both genders. Moreover, the total food intake was significantly low in the frail elderly. In male subjects, multiple logistic regression analyses after adjusting covariates showed that the odds ratio (OR) of frailty in the highest tertile of the consumption of fruits (OR [95% confidence interval, CI] = 0.34 [0.13-0.93], p-trend = 0.021) were significantly lower than values obtained in the lowest tertile. In females, the highest tertile of fish and shellfish intake showed a significantly lower OR for frailty (OR [95% CI] = 0.55 [0.30-0.99], p-trend = 0.045), as compared with the lowest tertile. Conclusion: The present study indicates that high intake of fruits for men, and fish and shellfish for women, are probably linked with lowering the risk of frailty in the elderly.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.4
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• pp.648-656
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• 2022

As environmental regulations such as the International Maritime Organization (IMO)'s strategy to reduce greenhouse gases(GHG) are strengthened, technology development such as eco-friendly ships and alternative fuels is expanding. As part of this, ship propulsion technology using energy reduction and wind propulsion technology is emerging, especially in shipping companies and shipbuilders. By securing wind propulsion technology and introducing empirical research into shipbuilding and shipping, a high value-added market using eco-friendly technology can be created. Moreover, by reducing the fuel consumption rate of operating ships, GHG can be reduced by 6-8%. Rotor Sail (RS) technology is to generate a hydrodynamic lift in the vertical direction of the cylinder when the circular cylinder rotates at a constant speed and passes through the fluid. This is called the Magnus effect, and this study attempted to propose a plan to increase propulsion efficiency through a numerical analysis study on turbulence flow characteristics around RS, a wind power assistance propulsion system installed on a ship. Therefore, C_L and C_D values according to SR and AR changes were derived as parameters that affect the aerodynamic force of the RS, and the flow characteristics around the rotor sail were compared according to EP application.

• Applied Chemistry for Engineering
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• v.34 no.4
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• pp.404-411
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• 2023

For the direct reforming of biogas, a three-phase gliding arc plasma reformer was designed to expand the plasma discharge region, and the operation conditions of the plasma reformer, such as the S/C ratio, the gas flow rate, and the plasma input power, were optimized. The H₂ production efficiency is increased at a lower specific plasma input energy density, but byproducts such as C_XH_Y and carbon soot are generated along with the increase in H₂ production efficiency. The formation of byproducts is decreased at higher specific plasma input energy densities and S/C ratios. The optimized operation conditions are 5.5 ~ 6.0 kJ/L for the specific plasma input energy density and 3 for the S/C ratio, considering the conversion efficiency, H₂ production, and byproduct formation. It is expected that the H₂ production efficiency will improve with the decrease in fuel consumption in biogas burners because the heat generated from plasma discharge heats up the feed gas to over 500 ℃.

• Journal of Nutrition and Health
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• v.49 no.2
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• pp.111-124
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• 2016

Purpose: The current study was conducted for evaluation and comparison of dietary behavior and food intake in different regions of Lao PDR. Methods: The survey was conducted on 979 people aged 40~59 years old living in 25 urban provinces and 25 rural provinces in four districts (VTE Capital-Chanthabuly, Xaysetha, VTE Province-Phonhong, and Thoulakhom) of Laos. General demographic information, health status, and dietary behavior were surveyed using a questionnaire. Results: The literacy ratio (p = 0.000), education level (p = 0.000), asset ownership level (p = 0.000), and government and private employee ratio (p = 0.000) were higher in urban subjects compared with rural subjects. The mean value of weight (p = 0.000), waist circumference (p = 0.000), and diastolic blood pressure (p = 0.009) and alcohol consumption (p = 0.000), self-rated health status (p = 0.001), and the rate of obesity (p = 0.000) were significantly higher in urban subjects compared with rural subjects. However, the rate of current smoker was significantly higher in the rural group (p = 0.023). Meals are becoming more westernized by higher frequency of eating out, consumption of fatty meat and fried or stir-fried food in urban areas compared to rural areas. Urban subjects had relatively better balanced meals compared to rural subjects whereas they consumed insufficient meals per day and consumed meals irregularly compared to rural subjects. Intake of fruit and milk was significantly higher in urban subjects compared with rural subjects. However, the intake of vegetables was significantly higher in rural areas than urban areas. Conclusion: The result of this study showed that the traditional Lao diet is being replaced by an unhealthy western dietary pattern, which may be a risk factor for increasing development of non-communicable disease (NCD) in Lao PDR. Planning of proper personalized nutritional intervention and education in each area is needed to decrease the health risks of NCD.

• Journal of Food Hygiene and Safety
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• v.24 no.4
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• pp.378-384
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• 2009

There are differences of Cadmium (Cd) urinary concentration which is considered as indicator of renal tubular dysfunction in other countries, so we have reviewed domestic epidemiological data and suggested Korean health based guidance value (HBGV) for Cd to improve an efficiency of risk management. We decided to apply the WHO calculation model which considered the relationship between dietary intake and Cd concentration in urine sample. It is determined that Cd concentration 2.5 ug/g creatinine in urine as the prevalence of renal tubular dysfunction based on epidemiological data, because there is no renal tubular dysfunction and injury/lesion such as proteinuria at the concentration of 11.63 ug/g creatinine which is the highest Cd concentration in urine from the domestic epidemiological data. It is identified that the ratio between the Cd dietary consumption (8.3~10.4 ug/day) and Cd urinary concentration (0.38 ug/g creatinine) in Korean adult who predicting never been exposed to Cd are 21.8~27.3 and then it is applied to the corresponding model suggested by WHO. Also it is applied that 10% of bioavailability and 50% of excretion rate of absorbed to body (the ratio is 24) were assumed. The estimate of daily Cd consumption level which begins tubular dysfunction is 1 ug/kg bw/day, so we suggest the Korean provisional tolerable weekly intake (PTWI) as 7 ug/kg bw/week.

• The Korean Journal of Community Living Science
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• v.16 no.4
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• pp.139-157
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• 2005

In rural area, as the source of family income is related with the agriculture works, the living condition of non-farming family used to be lower except some family groups with a little higher income. In order to find out the improvement in rural life, data about the health behavior and diet habits of non-farming family were observed. This study evaluated the health behavior and diet habits of non-farming families by comparing them with those of the farming families in rural area. The survey was made by trained interviewers and a total of 1,870 subjects from 9 provinces were questioned to collect the data through sampling probability proportional to size. The non-farming families were $29.6\%$ of the total and they were with no spouse($38\%$), low number of family members(2.86), and aged husband(66.8 years) or wife(58.5 years). $83.1\%$ of the non farming families were having breakfast however, $95.1\%$ of the farming families were doing it. And the number of side dishes in non farming families was low(1-2 kinds: $17.7\%$). Out of non farming families, $47.3\%$ took no nutritional supplements and out of the farming families it was 40.8 $\%$ With regard to having snacks, $22\%$ of non-farmers had snacks daily and it was greater than that of farmers($16.6\%$). But the ratio of non-snack taking of the non-farmers($29.6\%$) was higher than that of farmers($24.5\%$). The sorts of snacks also varied and for farmers it used to be fruit and noodles and for non-farmers it was bread and milk. Instant foods were often selected by $35.6\%$ of non-farmers. Dining out with a frequency of once per month was reported in $23.2\%$ of non-farming families, but $47.6\%$ of them did not dine out at all. In case of food production for family consumption, small portion of non-farmers cultivated pepper($13.3\%$), Korean cabbage ($16.2\%$), and sesame($6.2\%$) but almost all of the farmers cultivated such crops. However, non-farmers produced soybean sprouts($0.7\%$), soybean curd($0.2\%$), and eggs($7.2\%$) and it was compared with the fact that farmers produced soybean sprouts($9.7\%$), soybean curd ($4.6\%$), and eggs($5.1\%$). Non-farmers stocked the fermented foods: Doenjang ($57.8\%$), Kochujang ($56.1\%$), Kanjang ($53.6\%$), Kimchi ($77.9\%$) and Jangajji ($37.2\%$), and this ratios were smaller than those of farmers: Doenjang ($93.6\%$), Kochujang ($92.9\%$), Kanjang ($87.9\%$), Kimchi ($97.7\%$) and Jangajji ($66.7\%$). As to health behavior of the subjects, non-farmers had less medical examinations and bathing than farmers did. Non-farmers and their wives used public bath facilities more often and it may be due to the low condition of bathing facilities. And the ratio of daily alcohol consumption was $15\%$ and it was higher than that of the farmers. Most of the spouse of the farmers did not drink($78\%$), but the wives of the non-farmers were drinking more frequently. More farmers smoked than non-farmers and $45\%$ of male farmers were smokers.