• Korean Journal of Agricultural Science
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• v.8 no.2
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• pp.195-202
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• 1981

The return of water to the atmosphere from water, soil and vegetation surface is one of the most important aspects of hydrological cycle, and the seasonal trend of variation of river basin evaporation is also meaningful in the longterm runoff analysis for the irrigation and water resources planning. This paper has been prepared to show some imformation to estimate the monthly river basin evaporation from pan evaporation, potential evaporation, regional evaporation and temperature through the comparison with river basin evaporation derived from water budget method. The analysis has been carried out with the observation data of Yongdam station in the Geum river basin for five year. The results are summarized as follows and these would be applied to the estimation of river basin evaporation and longterm runoff in ungaged station. 1. The ratio of pan evaporation to river basin evaporation ($E_w/E_{pan}$) shows the most- significant relation at the viewpoint of seasonal trend of variation. River basin evaporation could be estimated from the pan evaporation through either Fig. 9 or Table-7. 2. Local coefficients of cloudness effect and wind function has been determined to apply the Penman's mass and energy transfer equation to the estimation of river basin evaporation. $R_c=R_a(0.13+0.52n/D)$ $E=0.35(e_s-e)(1.8+1.0U)$ 3. It seems that Regional evaporation concept $E_R=(1-a)R_C-E_p$ has kept functional errors due to the inapplicable assumptions. But it is desirable that this kind of function which contains the results of complex physical, chemical and biological processes of river basin evaporation should be developed. 4. Monthly river basin evaporation could be approximately estimated from the monthly average temperature through either the equation of $E_w=1.44{\times}1.08^T$ or Fig. 12 in the stations with poor climatological observation data.

• Journal of Animal Science and Technology
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• v.45 no.3
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• pp.369-376
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• 2003

This experiment was conducted to investigate the influence of different levels of metabolizable energy (ME) and crude protein (CP) on post-molt performance and egg quality of spent laying hens. Four hundred and thirty two, ISA Brown hens at sixty six weeks of age after molt induction were fed six experimental diets containing three ME (2,750, 2,800, 2,850 kcal/kg) with two CP (15, 17%) levels in a factorial design. The influence of ME and CP were evaluated on egg production, egg weight and feed intake throughout 24 weeks of production. Egg mass and feed conversion ratio (FCR) were measured during the experimental period. Haugh unit, yolk color and eggshell breaking strength were measured at 5%, 50%, peak, post peak and end stage of egg production. The hens fed 2800 kcal/kg diet along with 15% CP recorded the highest outcome of egg production (P<0.05). The egg weight has been shown to increase with hens receiving 2,800 kcal/kg ME. Daily egg mass tended to increase in hens fed with 15% CP and 2,800 kcal/kg ME. Feed intake decreased significantly with the level of ME and CP in the diet increased (P<0.05). Yolk color was improved significantly in eggs laid by the hens receiving 17% CP than 15% diet. It also tended to be higher in 17% CP with 2,800 or 2,850 kcal/kg ME diet treatments. Egg shell breaking strength increased with hens receiving diets of 15% CP and 2,800 kcal/kg. From this experiment it can be concluded that the ME level of 2,800 kcal/kg coupled with 15% CP could be used to achieve the higher egg production and better eggshell strength in induced molting hens.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.89.1-89.1
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• 2010

Since Gratzel and co-workers developed a new type of solar cell based on the nanocrystalline $TiO_2$ electrode, dye-sensitized solar cells (DSSCs) have attracted considerable attention on account of their high solar energy-to-conversion efficiencies (11%), their easy manufacturing process with low cost production compared to conventional p-n junction solar cells. The mechanism of DSSC is based on the injection of electrons from the photoexcited dye into the conduction band of nanocrystalline $TiO_2$. The oxidized dye is reduced by the hole injection process from either the hole counter or electrolyte. Thus, the electronic structures, such as HOMO, LUMO, and HOMO-LUMO gap, of dye molecule in DSSC are deeply related to the electron transfer by photoexcitation and redox potential. To date, high performance and good stability of DSSC based on Ru-dyes as a photosensitizer had been widely addressed in the literatures. DSSC with Ru-bipyridyl complexes (N3 and N719), and the black ruthenium dye have achieved power conversion efficiencies up to 11.2% and 10.4%, respectively. However, the Ru-dyes are facing the problem of manufacturing costs and environmental issues. In order to obtain even cheaper photosensitizers for DSSC, metal-free organic photosensitizers are strongly desired. Metal-free organic dyes offer superior molar extinction coefficients, low cost, and a diversity of molecular structures, compared to conventional Ru-dyes. Recently, novel photosensitizers such as coumarin, merocyanine, cyanine, indoline, hemicyanine, triphenylamine, dialkylaniline, bis(dimethylfluorenyl)-aminophenyl, phenothiazine, tetrahydroquinoline, and carbazole based dyes have achieved solar-to-electrical power conversion efficiencies up to 5-9%. On the other hand, organic dye molecules have large ${\pi}$-conjugated planner structures which would bring out strong molecular stacking in their solid-state and poor solubility in their media. It was well known that the molecular stacking of organic dyes could reduce the electron transfer pathway in opto-electronic devices, significantly. In this paper, we have studied on synthesis and characterization of dendritic organic dyes with different number of electron acceptor/anchoring moieties in the end of dendrimer. The photovoltaic performances and the incident photon-to-current (IPCE) of these dyes were measured to evaluate the effects of the dendritic strucuture on the open-circuit voltage and the short-circuit current.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.117.2-117.2
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• 2011

Since Gratzel and co-workers developed a new type of solar cell based on the nanocrystalline TiO2 electrode, dye-sensitized solar cells (DSSCs) have attracted considerable attention on account of their high solar energy-to-conversion efficiencies (11%), their easy manufacturing process with low cost production compared to conventional p-n junction solar cells. The mechanism of DSSC is based on the injection of electrons from the photoexcited dye into the conduction band of nanocrystalline TiO2. The oxidized dye is reduced by the hole injection process from either the hole counter or electrolyte. Thus, the electronic structures, such as HOMO, LUMO, and HOMO-LUMO gap, of dye molecule in DSSC are deeply related to the electron transfer by photoexcitation and redox potential. To date, high performance and good stability of DSSC based on Ru-dyes as a photosensitizer had been widely addressed in the literatures. DSSC with Ru-bipyridyl complexes (N3 and N719), and the black ruthenium dye have achieved power conversion efficiencies up to 11.2% and 10.4%, respectively. However, the Ru-dyes are facing the problem of manufacturing costs and environmental issues. In order to obtain even cheaper photosensitizers for DSSC, metal-free organic photosensitizers are strongly desired. Metal-free organic dyes offer superior molar extinction coefficients, low cost, and a diversity of molecular structures, compared to conventional Ru-dyes. Recently, novel photosensitizers such as coumarin, merocyanine, cyanine, indoline, hemicyanine, triphenylamine, dialkylaniline, bis(dimethylfluorenyl)-aminophenyl, phenothiazine, tetrahydroquinoline, and carbazole based dyes have achieved solar-to-electrical power conversion efficiencies up to 5-9%. On the other hand, organic dye molecules have large ${\pi}$-conjugated planner structures which would bring out strong molecular stacking in their solid-state and poor solubility in their media. It was well known that the molecular stacking of organic dyes could reduce the electron transfer pathway in opto-electronic devices, significantly. In this paper, we have studied on synthesis and characterization of dendritic organic dyes with different number of electron acceptor/anchoring moieties in the end of dendrimer. The photovoltaic performances and the incident photon-to-current (IPCE) of these dyes were measured to evaluate the effects of the dendritic strucuture on the open-circuit voltage and the short-circuit current.

• Journal of the East Asian Society of Dietary Life
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• v.5 no.1
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• pp.41-51
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• 1995

Bone mass accretion during puberty appears to be critical in the development of peak bone mass. Although bone density of females in Korea has been studied, only a few studies have related bone mass with anthropometric patterns or puberty in the pubescent girls. This study was conducted as part of a study of major determinants of bone development during puberty. Subjects were aged 14∼16 yr(mean 14.97), and had no history of disorders or dedication use likely to influence bone or calcium metabolism. Bone mineral density and content were measured by dual energy X-ray absorptiometry using a Lunar DPX+Scanner (Lunar Madison, WI). Also, total body fat, and total lean body mass were assessed using a Lunar DPX dual-energy X-ray absorptiometer, Pubertal status was assessed according to the Marshall and Tanner guidelines. Serum levels of osteocalcin was measured by RIA using a commercial kit assay. Skinfold measurements were taken with a skinfold caliper(Lange Caliper, USA). Data were analyzed using the regression and GLM procedure of the statistical package SAS. The results indicated that the observed means for lumbar spine BMD and femoral BMD correspond to approximately 91% and 96% of the means for young adult females, respec tively. All subjects were menarchal, with the majority being in the middle to end stages of pubertal development. Total body BMD was positively related to fat mass(P<0.001), lean body mass and time since menarche, and negatively related to urine pyridinoline, serum alkaline phosphatase and osteocalcin. The data indicate that girls who reported lower age for menarche had significantly higher bone densities than girls who reported higher age for menarche. Attaining peak skeletal bone mass during puberty may reduce the incidence of osteoporosis in later life. this finding suggests that early menarche may augment peak bone mass, influencing the extent of bone loss later in adulthood. The results suggest that good nutrition in childhood appears to be needed not for growth and development, but possibly also to assure an optimal peak of bone mass and thus greater latitude for the maintenance or skeletal integrity in the face of bone losses. Troeps skinfold thickness was a better predictor of total BMD and total BMC than was any other skinfold thickness. The study did not find a relationship between total BMD and body fat %, but total fat was significantly positively related to total BMD(r=0.49) and total BMC(r=0.60). It supports earlier report that there was a significant correlation between TBMD and body weight. Conclusively, total fat, lean body mass and pubertal development could influence BMD in pubescent girls. Clearly, longitudinal studies are required to assess the effect of puberty on peak bone mass, and to define further the potential determinants of peak bone mass.

• Economic and Environmental Geology
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• v.42 no.5
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• pp.445-455
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• 2009

Microbiological sulfate reduction is the transformation of sulfate to sulfide catalyzed by the activity of sulfate-reducing bacteria using sulfate as an electron acceptor. Low solubility of metal sulfides leads to precipitation of the sulfides in solution. The effects of microbiological sulfate reduction on in-situ precipitation of arsenic and copper were investigated for the heavy metal-contaminated soil around the Songcheon Au-Ag mine site. Total concentrations of As, Cu, and Pb were 1,311 mg/kg, 146 mg/kg, and 294 mg/kg, respectively, after aqua regia digestion. In batch-type experiments, indigenous sulfate-reducing bacteria rapidly decreased sulfate concentration and redox potential and led to substantial removal of dissolved As and Cu from solution. Optimal concentrations of carbon source and sulfate for effective microbial sulfate reduction were 0.2~0.5% (w/v) and 100~200 mg/L, respectively. More than 98% of injected As and Cu were removed in the effluents from both microbial and chemical columns designed for metal sulfides to be precipitated. However, after the injection of oxygen-rich solution, the microbial column showed the enhanced long-term stability of in-situ precipitated metals when compared with the chemical column which showed immediate increase in dissolved As and Cu due to oxidative dissolution of the sulfides. Black precipitates formed in the microbial column during the experiments and were identified as iron sulfide and copper sulfide. Arsenic was observed to be adsorbed on surface of iron sulfide precipitate.

• Korean Journal of Environmental Biology
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• v.32 no.1
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• pp.26-34
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• 2014

Due to the rapid energy consumption and fossil fuel abundance reduction, the world is progressively in need of alternative and renewable energy sources such as biodiesel. Biodiesel from microalgae offers high hopes to the scientific world for its potential as well as its non-competition with arable lands. Taking consideration to reduce the cost of production as well as to attain twin environmental goals of treatment and use of animal waste material the microalgal cultivation using piggery manure has been tested in this study. Unialgal strains such as Chlorella sp. JK2, Scenedesmus sp. JK10, and an indigenous mixed microalgal culture CSS were cultured for 20 days in diluted piggery manure using Small Scale Raceway Pond (SSRP). Biomass production and lipid productivity of CSS were $1.19{\pm}0.09gL^{-1}$, $12.44{\pm}0.38mgL^{-1}day^{-1}$, respectively and almost twice that of unialgal strains. Also, total nitrogen and total phosphorus removal efficiencies of CSS was 93.6% and 98.5% respectively and 30% higher removal efficiency compared to the use of unialgal strains. These results indicate that the piggery manure can provide microalgae necessary nitrogen and phosphorus for growth thereby effectively treating the manure. In addition, overall cost of microalgal cultivation and subsequently biodiesel production would be significantly reduced.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.14-18
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• 2019

The conductivity of a semiconductor is primarily determined by the carriers. To achieve higher conductivity, the number of carriers should be high, and an energy trap level is created so that the carriers can cross the forbidden zone with low energy. Carriers have a crystalline binding structure, and interfacial mismatching tends to make them less conductive. In general, high-concentration doping is typically used to increase mobility. However, higher conductivity is also observed in non-orthogonal conjugation structures. In this study, the phenomena of higher conductivity and higher mobility were observed with space charge limiting current due to tunneling phenomena, which are different from trapping phenomena. In an atypical structure, the number of carriers is low, the resistance is high, and the on/off characteristics of capacitances are improved, thus increasing the mobility. ZTO thin film improved the on/off characteristics of capacitances after heat treating at $150^{\circ}C$. In charging and discharging tests, there was a time difference in the charge and discharging shapes, there was no distinction between n and p type, and the bonding structure was amorphous, such as in the depletion layer. The amorphous bonding structure can be seen as a potential barrier, which is also a source of space charge limiting current and causes conduction as a result of tunneling. Thus, increased mobility was observed in the non-structured configuration, and the conductivity increased despite the reduction of carriers.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.8
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• pp.1302-1310
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• 2004

The purpose of this study was to investigate whether a web-based nutrition counseling could lead to beneficial outcomes in food intake and serum lipids of patients with hyperlipidemia. Forty hyperlipidemic patients, twenty of them were hypercholesterolemia and the other twenty were hypertriglyceridemia, participated in a web-based nutrition counseling program. At the first nutrition counseling, the patients were counselled through interview and then follow up nutrition counseling was accomplished four times during eight weeks through a web-based internet program. Various markers of disease risk including anthropometric indices, food intakes and serum lipid levels were measured before and after the web-based nutrition counseling. After nutrition counseling, body mass index significantly decreased in both groups and waist to hip ratio significantly decreased in male hypercholesterolemic patients (p<0.05). Total-cholesterol decreased from 262.2 mg/dL to 234.9 mg/dL, LDL-cholesterol decreased from 186.8 mg/dL to 160.5 mg/dL in hypercholesterolemic patients, triglyceride decreased from 288.6 mg/dL to 211.9 mg/dL and total-cholesterol decreased from 217.2 mg/dL to 198.7 mg/dL in hypertriglyceridemic patients after nutrition counseling. Anthropometric value and nutrient intakes were improved after nutrition counseling. Energy, fat and saturated fatty acid intakes decreased significantly in both groups (p<0.05). Therefore, this study shows that the web-based nutrition counseling is effective in improving food habit and influences positively in serum lipid levels of the patients. In addition, these results indicate that internet presents us with potential as a new medium for nutrition counseling in informationized society.

• Journal of Animal Science and Technology
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• v.56 no.3
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• pp.10.1-10.7
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• 2014

An experiment was conducted to investigate the effects of dietary supplementation with citrus pulp, fish by-product, and Bacillus subtilis fermentation biomass on the growth performance, apparent total tract digestibility (ATTD) of nutrients, and fecal microflora of weanling pigs. A total of 180 weaned piglets (Landrace ${\times}$ Yorkshire ${\times}$ Duroc) were randomly allotted to three treatments on the basis of body weight (BW). There were six replicate pens in each treatment with 10 piglets per pen. Dietary treatments were corn-soybean meal-based basal diet supplemented with 0 (control), 2.5, and 5.0% citrus pulp, fish by-product, and B. subtilis fermentation biomass. The isocaloric and isoproteineous experimental diets were fed in mash form in two phases (d 0 ~ 14, phase I and d 15 ~ 28, phase II). Dietary treatments had significant linear effects on gain to feed ratio (G:F) in all periods, whereas significant linear effects on ATTD of dry matter (DM), gross energy (GE), and ash were only observed in phase I. Piglets fed diet supplemented with 5.0% citrus pulp, fish by-product, and B. subtilis fermentation biomass showed greater (p < 0.05) G:F (phase I, phase II, and overall) as well as ATTD of DM, GE, and ash (phase I) than pigs fed control diet. Dietary treatments also had significant linear effects on total anaerobic bacteria populations by d 14 and 28. In addition, piglets fed diet supplemented with 5.0% citrus pulp, fish by-product and B. subtilis fermentation biomass showed greater (p < 0.05) fecal total anaerobic bacteria populations (d 14 and 28) than pigs fed control diet. Dietary treatments had no significant effects (linear or quadratic) on average daily gain (ADG), average dial feed intake (ADFI; phase I, phase II, and overall), or fecal populations of Bifidobacterium spp., Clostridium spp., and coliforms (d 14 and 28). These results indicate that dietary supplementation with 5.0% citrus pulp, fish by-product, and B. subtilis fermentation biomass has the potential to improve the feed efficiency, nutrient digestibility, and fecal microflora of weanling pigs.