• 한국식품영양학회지
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• 제11권6호
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• pp.647-686
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• 1998

The purpose of this study was to investigate selected nutrient intakes, dietary atherogenesity, energy balance and activity level of college students. One hundred and thirty onoe students (61 males and 70 females) made their three-day dietary records and one-day activity records along with one-day dietary records. BMI of the surveyed students was 22.33 for males and 20.28 for females. Average calorie intakes of male and female students was respectively 2166.20kcal and 1793.60kcal. Females had slightly higher fiber intakes than males in terms of fiber g/1000kcal. Carbohydrate, protein and fat ratios in energy composition of males and females were respectively 56.62 : 15.33 : 24.70 and 57.64 : 16.49 : 25.79. Average cholesterol intakes of male and female students were 295.66mg and 259mg respectively. The male showed higher saturated fat intake. and had higher atherogenic indices of diets such as cholesterol index(CI) and cholesterol-saturated fat index(CSI) than the female. Males spent an average of 1039.00 kcal/day compared to females of 687.93 kcal/day for all physical activities. Most students participated in light (100% of males and females) and moderate (33% of males and 3% of females) activities level. Few students spent time at severe and very severe activity level. Seventeen of the 131 students were in positive energy balance whereas 83% were in negative balance. Both genders with positive energy balance tended towards smaller weight and BMI, and larger food intakes than those with negative energy balance. Students with positive energy balance had higher saturated fat intakes and dietary atherogenic scores of CI and CSI than the counterparts with negative energy balance. Males with positive energy balance had decreased physical activity and daily energy expenditure whereas increased food and saturated fat intakes. Females with positive energy balance had singificantly increased food, saturated fat and sugar intakes.

• Journal of Electrochemical Science and Technology
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• 제2권3호
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• pp.152-156
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• 2011

A hybrid supercapacitor is fabricated using a composite material from $LiMn_2O_4$ (LMO) and activated carbon (AC) as the positive electrode and AC as the negative electrode to form the (LMO + AC)/AC system. Volume ratio (positive : negative) of electrodes is controlled to investigate of the power and energy balance. The (LMO + AC)/AC system shows better performances than the LMO/AC system. Especially, electrochemical impedance spectra, rate charge.discharge and cycle performance testing show that the (LMO + AC)/AC system have an outstanding electrochemical performance at volume ratios of (LMO + AC)/AC = 1 : 1.7 and 1 : 2. Electric double layer capacitor (EDLC) capacitance between AC of the positive electrode and AC of the negative electrode improves power density without loss of capacitance. Stable capacitance is achieved by lowering the positive electrode resistance and balancing the energy and power densities between the positive and negative electrodes by the addition of AC to the positive electrode at high current density.

• Journal of Nutrition and Health
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• 제27권4호
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• pp.336-346
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• 1994

balance and to estimate daily energy requirement in 43 Korean female college students maintaining their usual diet and activity level. Energy intake and expenditure were measured in two separate periods about one month apart, each period lasting for 3 days. All the subjects participated in both periods. Energy intake was assessed by two methods ; weighed diet record and duplicate portion analysis of diet minus fecal and urinary excretion. Mean daily energy intake level calculated from diet records was 28.5 kcal/kgB.W(1, 476 kcal/day), and similar to the level of 27.8 kcal/kgB.W(1, 438 kcal/days) obtained from the chemical analysis of duplicate portions. Mean daily energy expenditure, calculated from activity records of each subject, was 34.6 kcal/kgB.W, or 1.39 times BMR, which corresponds to light activity level. Mean daily energy balance of subjects was -5.9 kcal/kgB.W. Mean daily requirement of energy, calculated from the activity records of the subjects, was 34.6 kcal/kgB.W, similar to the level of the Korean RDA for light activity level. The results of this study indicate that 1) the activity level of the study subjects corresponds to the sedentary level ; 2) present Korean RDA for energy for light activity is adequate for the subjects ; and 3) the subjects should increase their energy intake since they are largely in negative energy balance.

• 드라이브 ㆍ 컨트롤
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• 제14권3호
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• pp.1-7
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• 2017

Energy consumption of conventional hydraulic excavators controlled by MCV is considerable when negative load is applied because the meter orifice and meter-out orifice are machined in one spool. Therefore, IMV is introduced to save energy use of hydraulic excavators, but existing hydraulic excavators have various advantages so it is difficult to make a clear comparison. In this study, we compare the use of an existing MCV excavator that has many advantages such as negative control, and IMV for boom up and down operation, and if IMV is used to save energy, we will examine the cause. If possible, for comparability under the same conditions, both systems use pressure balance valves to minimize power consumption when not using power in the actuator. The orifice area at each notch of each valve is calculated, and energy saving is verified by comparing the two systems through simulation.

• Animal Bioscience
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• 제37권3호
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• pp.522-535
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• 2024

Objective: Transition period is considered from 3 weeks prepartum to 3 weeks postpartum, characterized with dramatic events (endocrine, metabolic, and physiological) leading to occurrence of production diseases (negative energy balance/ketosis, milk fever etc). The objectives of our study were to analyze the periodic concentration of serum beta-hydroxy butyric acid (BHBA), glucose and oxidative markers along with identification, and validation of the putative markers of negative energy balance in buffaloes using in-silico and quantitative real time-polymerase chain reaction (qRT-PCR) assay. Methods: Out of 20 potential markers of ketosis identified by in-silico analysis, two were selected and analyzed by qRT-PCR technique (upregulated; acetyl serotonin o-methyl transferase like and down regulated; guanylate cyclase activator 1B). Additional two sets of genes (carnitine palmotyl transferase A; upregulated and Insulin growth factor; downregulated) that have a role of hepatic fatty acid oxidation to maintain energy demands via gluconeogenesis were also validated. Extracted cDNA (complementary deoxyribonucleic acid) from the blood of the buffaloes were used for validation of selected genes via qRTPCR. Concentrations of BHBA, glucose and oxidative stress markers were identified with their respective optimized protocols. Results: The analysis of qRT-PCR gave similar trends as shown by in-silico analysis throughout the transition period. Significant changes (p<0.05) in the levels of BHBA, glucose and oxidative stress markers throughout this period were observed. This study provides validation from in-silico and qRT-PCR assays for potential markers to be used for earliest diagnosis of negative energy balance in buffaloes. Conclusion: Apart from conventional diagnostic methods, this study improves the understanding of putative biomarkers at the molecular level which helps to unfold their role in normal immune function, fat synthesis/metabolism and oxidative stress pathways. Therefore, provides an opportunity to discover more accurate and sensitive diagnostic aids.

• Animal Bioscience
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• 제35권1호
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• pp.22-28
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• 2022

Objective: Endoplasmic reticulum (ER) stress engages the unfolded protein response (UPR) that serves as an important mechanism for modulating hepatic fatty acid oxidation and lipogenesis. Chronic fasting in mice induced the UPR activation to regulate lipid metabolism. However, there is no direct evidence of whether negative energy balance (NEB) induces ER stress in the liver of cows. This study aimed to elucidate the relationship between the NEB attributed to feed deprivation and ER stress in bovine hepatocytes. Methods: Blood samples and liver biopsy tissues were collected from 6 non-lactating cows before and after their starvation for 48 h. The blood non-esterified fatty acids (NEFA), β-hydroxybutyric acid (BHBA) and glucose level were analyzed. Real-time quantitative polymerase chain reaction and Western blotting were used to explore the regulation of genes associated with UPR and lipid metabolism. Results: The starvation increased the plasma BHBA and NEFA levels and decreased the glucose level. Additionally, the starvation caused significant increases in the mRNA expression level of spliced X-box binding protein 1 (XBP1s) and the protein level of phosphorylated inositol-requiring kinase 1 alpha (p-IRE1α; an upstream protein of XBP1) in the liver. The mRNA expression levels of peroxisome proliferator-activated receptor alpha and its target fatty acid oxidation- and ketogenesis-related genes were significantly upregulated by the starvation-mediated NEB. Furthermore, we found that the mRNA expression levels of lipogenic genes were not significantly changed after starvation. Conclusion: These findings suggest that in the initial stage of NEB in dairy cows, the liver coordinates an adaptive response by activating the IRE1 arm of the UPR to enhance ketogenesis, thereby avoiding a fatty liver status.

• 대기
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• 제16권2호
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• pp.111-124
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• 2006

This study examines seasonal variability of the surface energy balance at the King Sejong Station, Antarctica, using measurements and estimates of the components related to the balance for the period of 1996 to 2004. Annual average of downward shortwave radiation at the surface is 81 $Wm^{-2}$ which is 37% of the extraterrestrial value, with the monthly maximum of 188 $Wm^{-2}$ in December and the minimum of 8 $Wm^{-2}$ in June. These values are relatively smaller than those at other stations in Antarctica, which can be attributed to higher cloudy weather conditions in Antarctic front zone. Surface albedo varies between ~0.3 in the austral summer season and ~0.6 in the winter season. As a result, the net shortwave radiation ranges from 117 $Wm^{-2}$ down to 3 $Wm^{-2}$ with annual averages of 43 $Wm^{-2}$. Annual average of the downward longwave radiation shows 278 $Wm^{-2}$, ranging from 263 $Wm^{-2}$ in August to 298 $Wm^{-2}$ in January. The downward longwave radiation is verified to be dependent strongly on the air temperature and specific humidity, accounting for 74% and 79% of the total variance in the longwave radiation, respectively. The net longwave radiation varies between 25 $Wm^{-2}$ and 40 $Wm^{-2}$ with the annual averages of 30 $Wm^{-2}$. Accordingly, the annual average energy balance is dominated by radiative warming of a positive net all-wave radiation from September to next March and radiative cooling of a negative net all-wave radiation from April to August. The net all-wave radiative energy gain and loss at the surface is mostly balanced by turbulent flux of sensible and latent heat. The soil heat flux is of negligible importance in the surface energy balance.

• 한국식품영양과학회지
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• 제26권3호
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• pp.521-527
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• 1997

This study was aimed to investigate the nutriational status of Korean female college students who are attending school at a longdistance. Physique calssification by anthropomethic indexes, Body mass index(BMI) & Brocas' index and the body fat distrubition were investigated. The energy balance was also examined comparing caloric intake with caloric expenditure. The result of this study are followings; (1) Average height and weight were 158±17.8 cm, 51.7±7.8 kg. This results were not quite different from '84 Korean Adult Standard of 159.5cm, 52.5kg. (2) By Broca's index, 25.89% of subjects was underweight 67.0% was normal weight and 7.06 was overweight. By BMI, 40% of subjects was underweight, 58.8% was normal weight and 1.2% was overweight. (3) According to % fat measured. By BIA, 7% in subjects was underweight, 64.2% was normal weight, 22% was overweight and 6.1% was obesity. This result differed from BMI's result. It may be measurement error due to the difficulty of removing metal sticking to underwear and tooth correction. (4) The intakes of the nutrients except protein, P, vitamin B₁ complexes, were lower than the intakes indicated by Korean Recommended Allowances. 95) Average caloric intake a day was 1545±394.4 kcal, which was much lower than the RDA. The caloric expenditure was much more than caloric intake, which showed negative energy balance in the subjects of this study.

• Nutritional Sciences
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• 제4권1호
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• pp.34-38
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• 2001

The purpose of this study was to compare the energy expenditure of normal-weight and overweight Korean middle-aged women (40-60 yr). Middle-aged oveweight ($BMI\;{\geq}\;25$, n= 20) and normal-weight women were ($BMI\;{\leq}\;23$, n = 20) were recruited in Seoul. Anthropometric measurements, body composition, energy intake, daily activity time, and energy costs of some daily activities were measured. Energy expenditure at rest and while reading the newspaper, washing dishes, mopping the floor, and walking on a treadmill at 1.0, 2.0, 3.5mph were measured by indirect calorimeter and total daily energy expenditure was estimated by summation of energy costs of different activities. The overweight group had significantly higher values of body weight, triceps skinfold thickness, thigh circumference, waist circumference, hip circumference, BMI, WTR, WHR, body surface area, percentage body fat, fat mass, fat free mass (FFM), and muscle mass compared to normal-weight group. The energy intakes of both groups were close to RDA and other nutrient intake status was also satisfactory. There were no significant differences in intakes of energy and nutrients between the two groups. Overweight subjects showed lower energy expenditure per kg body weight for reading the newspaper, washing dishes and mopping the floor, and walking on a treadmill at 2.0 and 3.5 mph, however, energy expenditure per kg FFM did not differ between the two groups. Daily energy expenditure for all activities was significantly higher in the overweight compared to the normal-weight group due to higher body weight. Both overweight and normal-weight groups showed negative energy balance between energy intake and energy expenditure, and there was no significant difference in energy balance between the two roups. Total daily energy expenditure correlated highly with FFM and body surface area. The result of present study does not offer an explanation on the energy imbalance and weight gain of overweight women.

• Asian-Australasian Journal of Animal Sciences
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• 제24권4호
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• pp.540-572
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• 2011

The present review focuses on the effects of energy intake on performance, changes in body tissue during lactation, and metabolic parameters in dairy cows. Especially, pre-partum nutrition and its influence on lactation are emphasized. In recent decades the increase in genetic potential of dairy cows has increased milk yield. This fact sharpens the problem of a negative energy balance in early lactation because the amount of energy required for maintenance and milk production exceeds the amount of energy cows can consume. Around parturition, reduced feed intake reinforces the situation. Continuing negative energy balance causes decreasing milk yield, fertility problems, and incidence of metabolic diseases. Hence, the cow has to rely on body reserves that were stored in late lactation and the dry period. It is evident that the nutritional status pre-partum acts as the key factor for milk yield and fertility parameters in the following lactation. Cows overfed during the foregoing gestation and which have gained large quantities of body fat have lower dry matter intake along with the need to mobilize larger quantities of body reserves in lactation. The milk yield in the following lactation is lower than in cows fed according to their requirements. Cows restrictively fed in late gestation have a higher feed intake in lactation and a lower mobilization of body reserves. The effect of energy intake post-partum plays only a minor role for performance parameters in lactation. Lipid mobilized from body reserves makes a substantial contribution to the energetic cost of milk production in early lactation and adipose tissue undergoes specific metabolic alterations. Adipose tissue is degraded to free fatty acids, which are used in liver for energy purposes. High lipid mobilisation promotes the development of a fatty liver and therefore a reduced gluconeogenesis.