• Korean Journal of Veterinary Research
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• v.40 no.2
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• pp.383-391
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• 2000

Milk urea nitrogen (MUN) determination is being used an indicator of the protein-energy balance in dairy herds. A faulty balance can be corrected to optimize milk production and animal health. This parameter is regarded as a potential tool to evaluate suboptimal feeding practices and reproductive disorders. Therefore, the purpose of this study was to investigate the response of milk composition by regular feeding analysis and to compared the relationship between MUN and milk protein(MP) and fertility at the insemination period in Holstein dairy cows. Total of 355 artificial insemination (AI) for 150 Holstein cows in the herd were used to examine the relationship between MUN and MP content and conception rate. The AI occured for the cows 50 to 150 day in milk, and MUN and MP concentration were determined using automated infrared procedures. The mean${\pm}$standard deviation of MUN and MP concentration in the herd were $15.6{\pm}2.1mg/dl$ and $3.23{\pm}0.38%$, respectively. MUN contents of bulk milk were increase by elevated crude protein intake. The conception rate was lower in the cows in which the level of MUN was lower than > 8.0mg/dl (10.0%) or > higher than 25mg/dl (15.4%) relative to the cows in MUN content of 12.0~17.9 mg/dl (36.7%) at the time of insemination. Also, lower MP than 3.0% or higher MP than 3.25% were associated with a lower conception rates. Consequently, MUN and MP analyses may be used serve as a monitoring tool of protein and energy nutritional balance to improve reproduction efficiency in Holstein dairy cows.

• Journal of the Korean Magnetics Society
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• v.18 no.6
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• pp.206-210
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• 2008

According to the recent reports the bulk bcc Rh is ferromagnetic with a small difference of energy compared to paramagnetic state. In this study, the electronic structure and magnetism for bcc Rh(001) surface are investigated by means of the all-electron full potential linearized augmented plane wave method within the generalized gradient approximation. It is found that the surface ferromagnetic state is preferable over the paramagnetic one. For unrelaxed system, the magnetic moment of the surface layer, $0.48{\mu}B$, is slightly increased comparing with the bulk value, $0.41{\mu}B$ while the value of the subsurface layer, $0.23{\mu}B$, is much smaller than the bulk value. The total energy and atomic force calculations show that the surface layer is relaxed downward and the subsurface layer moves upward to reduce the layer distance between the surface and subsurface layers by 7.0 %. The relaxation effect leads to weakening the surface magnetic properties. Specifically, the value of the magnetic moment of the surface atom is decreased to $0.36{\mu}B$. Since the spin polarization of the subsurface layer is only $0.14{\mu}B$, it is concluded that the bcc Rh(001) surface is rather weakly ferromagnetic.

• 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.

• Journal of the Korean Magnetics Society
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• v.26 no.1
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• pp.1-6
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• 2016

Pd has the highest magnetic susceptibility among single element metals and often shows ferromagnetism under some special environments. In this paper, we report magnetism of 5- and 9-monolayers (ML) calculated by using full-potential linearized augmented plane wave method. Exchange-correlation interaction is taken into account in local density approximation (LDA) and generalized gradient approximation (GGA) and calculational results in LDA and GGA are compared with each other. It is found that calculations by LDA are more reliable compared to those by GGA because LDA prediction of paramagnetism of bulk Pd is consistent with experiments, whereas GGA predicts wrongly ferromagnetim of bulk Pd. Calculational results in LDA on a 5-ML Pd(111) thin film shows a ferromagnetic ground state unlike a paramagnetic ground state of bulk Pd. The center Pd layer of the 5-ML Pd(111) thin film has the largest magnetic moment ($0.273{\mu}_B$) among the layers and |m| = 1 orbital states play a dominant role in stabilizing the ferromagnetism of the 5-ML Pd(111) thin film. A 9-ML Pd(111) thin film in a ferromagnetic state has almost the same total energy as in a paramagnetic state. Since the magnetization of the 9-ML Pd(111) thin film is stable, the ferromagnetic state may be meta-stable.

• Korean Chemical Engineering Research
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• v.56 no.4
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• pp.496-523
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• 2018

The objective of this study is to evaluate the economic feasibility of two fast pyrolysis and biooil upgrading (FPBU) plants including feed drying, fast pyrolysis by fluidized-bed, biooil recovery, hydro-processing for biooil upgrading, electricity generation, and wastewater treatment. The two FPBU plants are Case 1 of an FPBU plant with steam methane reforming (SMR) for $H_2$ generation (FPBU-HG, 20% yield), and Case 2 of an FPBU with external $H_2$ supply (FPBUEH, 25% yield). The process flow diagrams (PFDs) for the two plants were constructed, and the mass and energy balances were calculated, using a commercial process simulator (ASPEN Plus). A four-level economic potential approach (4-level EP) was used for techno-economic analysis (TEA) under the assumption of sawdust 100 t//d containing 40% water, 30% equity, capital expenditure equal to the equity, $H_2$ price of $1050/ton, and hydrocarbon yield from dried sawdust equal to 20 and 25 % for Case 1 and 2, respectively. TCI (total capital investment), TPC (total production cost), ASR (annual sales revenue), and MFSP (minimum fuel selling price) of Case 1 were $22.2 million, $3.98 million/yr, $4.64 million/yr, and $1.56/l, respectively. Those of Case 2 were $16.1 million, $5.20 million/yr, $5.55 million/yr, and $1.18/l, respectively. Both ROI (return on investment) and PBP (payback period) of Case 1(FPBU-HG) and Case 2(FPBU-EH) were the almost same. If the plant capacity increases into 1,500 t/d for Case 1 and Case 2, ROI would be improved into 15%/yr.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.1
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• pp.13-20
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• 2013

An emergy concept was used to evaluate the contributions of the Youngsan River Estuary to the Korean economy from systems and ecosystem service perspectives. Total emergy input to the estuary was $9.42{\times}10^{20}$ sej/yr with the chemical potential of river inflow accounting for 73% of the total and tidal energy for the remaining 27%, reflecting the unique environmental characteristics of estuaries where rivers meet sea. From the systems perspective, the estuary ecosystem contributed 179.9 billion em\/yr (14.91 million em\/ha/yr or 13,526 em$/ha/yr). Four ecosystem services of the Youngsan River Estuary were selected for the emergy evaluation: fishery production, pollutant removal, aesthetic function, and scientific research information. Aesthetic function contributed the most to the Korean economy with 179.9 billion em\/yr, followed by fishery production (101.1 billion em\/yr), pollutant removal (32.6 billion em\/yr), and scientific research information (934 million em\/yr). Emergy-based values of the selected ecosystem services of the estuary were higher than those calculated by economic methodologies.

• Journal of Preventive Medicine and Public Health
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• v.32 no.4
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• pp.526-537
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• 1999

Objectives : It is known that the prevalence of diabetes mellitus(DM) appears to be rapidly increasing in recent times in Korea, presumably due to a westernized diet and change of life style followed by rapid economic growth. Based on the Seoul male cohort which was constructed in 1993, this study was conducted to estimate the annual incidence rates of DM through 4 years' follow up and to determine which factors are associated with DM risk in Korean middle-aged men. Methods : Among 14,533 men recruited at baseline, 559 were excluded because they reported a history of diabetes or were found to be diabetes at 1992 routine health examination. During 4 years' follow-up, 237 incident DM cases were ascertained through chart reviews and telephone contacts for those who have ever visited hospitals or clinics under suspicion of DM during 1993-1996 and the biennial routine health examinations in 1994 and 1996. Results : In this study the annual incidence of DM among the study population was estimated to be 0.5 per 100. This study showed that fasting glucose level at initial baseline examination was a powerful predictor of risk for diabetes several years later(fasting blood glucose of $\geq$ 110 mg/dl compared with $\leq$ 80 mg/dl, Hazard Ratio[HR]:15.6, 95% Confidence interval[CI]=9.1-26.6) after considering potential covariates such as age, family history, smoking and alcohol history, body mass index, physical activity, total energy intake, and total fiber intake. Adjusted hazard ratios of family history of diabetes was 1.95(95% CI=1.38-2.75); of obesity as measured by BMI(BMI $\geq$ 25.3 compared with $\leq$ 21.3) was 7.19(95% CI=3,75-13.8); of weight change during middle life(>10kg compared with $\leq$ 5) was 1.77(95% CI=1.16-2.69); of smoking(current vs none) was 1.93(95% CI=1.06-3.51); and fat intake(upper fertile compared with lower fertile) was 1.88(95% CI=1.01-3.49), while fiber intake was associated with the reduced risk(HR=0.36, 95% CI=0.19-0.67). Conclusion : The factors identified in this study indicate that the greatest reduction in risk of diabetes might be achieved through population-based efforts that promote fiber intake and reduce obesity, smoking, and fat intake.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.9
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• pp.1217-1226
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• 2011

Finding alternative feeds, such as sesame hulls and Prosopis juliflora species can attenuate difficulties of feed shortage and reduce the cost of animal feed in arid and semi-arid countries. Thirty-two Black male kids with similar initial weights (BW = $16.7{\pm}0.80\;kg$) and $120{\pm}5\;d$ of age, were used to evaluate the effect of replacing barley grains and soybean meal with Prosopis juliflora pods (PJP) and sesame hulls (SH) on growth performance, digestibility and carcass and meat characteristics. Kids were equally divided into four dietary treatment groups for an 84-d fattening period. Treatment diets had similar crude protein (CP) and metabolizable energy (ME). The treatment groups were: (T1) no PJP nor SH, (T2) 10% PJP and 20% SH, (T3) 15% PJP and 15% SH, and (T4) 20% PJP and 10% SH. A tendency was detected (p<0.08) for dry matter (DM), crude protein (CP), organic matter (OM) and neutral detergent fiber (NDF) intakes that were greater for T2 than T3 and T4 while T1 was not different from all other treatment groups. Ether extract (EE) intake was the greatest (p<0.05) for T2 and the lowest for T1. Acid detergent fiber (ADF) intake was greater (p<0.05) for T2 than T1 while T3 and T4 were intermediate. Final live weight, average daily gain (ADG) and feed conversion ratio (FCR) were comparable among different treatment groups. Digestibility of DM, OM, CP, NDF and ADF were similar among all treatment groups, however, EE digestibility was the lowest (p<0.05) for T1 when compared to other treatments. In addition, nitrogen intake, nitrogen in urine and retained and retention percentages were similar among all treatment groups. However, N loss in feces was higher (p<0.05) for T2 than T3 and T4 while T1 was intermediate. No differences were observed among treatment groups with respect to fasting live weight, hot and cold carcass weights, dressing-out percentages, mesenteric fat, visceral organs, carcass cuts percentages and carcass linear dimensions. No differences were also observed for dissected loin, leg, rack and shoulder tissues except in the total bone % for loin cuts and in the meat to bone ratio for rack cuts. T3 has the greatest total bone % and the lowest meat to bone ratio when compared to all other treatment groups. No differences were observed between treatment groups in all quality characteristics of the longissimus muscle. The present study demonstrates the potential of using PJP and SH for growing kids without adverse effects on growth performance, carcass characteristics and meat quality.

• Journal of Ginseng Research
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• v.40 no.2
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• pp.127-134
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• 2016

Background: Rhizospheric fungi play an essential role in the plantesoil ecosystem, affecting plant growth and health. In this study, we evaluated the fungal diversity in the rhizosphere soil of 2-yr-old healthy Panax notoginseng cultivated in Wenshan, China. Methods: Culture-independent Illumina MiSeq and culture-dependent techniques, combining molecular and morphological characteristics, were used to analyze the rhizospheric fungal diversity. A diffusion test was used to challenge the phytopathogens of P. notoginseng. Results: A total of 16,130 paired-end reads of the nuclear ribosomal internal transcribed spacer 2 were generated and clustered into 860 operational taxonomic units at 97% sequence similarity. All the operational taxonomic units were assigned to five phyla and 79 genera. Zygomycota (46.2%) and Ascomycota (37.8%) were the dominant taxa; Mortierella and unclassified Mortierellales accounted for a large proportion (44.9%) at genus level. The relative abundance of Fusarium and Phoma sequenceswas high, accounting for 12.9% and 5.5%, respectively. In total,113 fungal isolates were isolated from rhizosphere soil. They were assigned to five classes, eight orders (except for an Incertae sedis), 26 genera, and 43 species based on morphological characteristics and phylogenetic analysis of the internal transcribed spacer. Fusarium was the most isolated genus with six species (24 isolates, 21.2%). The abundance of Phoma was also relatively high (8.0%). Thirteen isolates displayed antimicrobial activity against at least one test fungus. Conclusion: Our results suggest that diverse fungi including potential pathogenic ones exist in the rhizosphere soil of 2-yr-old P. notoginseng and that antagonistic isolates may be useful for biological control of pathogens.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.128-128
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• 2017

Copper (Cu) is very toxic to plant cells due to its inhibitory effects on many physiological and biochemical processes. In spite of its potential physiological and economic significance, molecular characterization after Cu stress has so far been grossly overlooked in sorghum. To explore the molecular alterations that occur in response to copper stress, the present study was executed in ten-day-old Cu-exposed leaves of sorghum seedlings. The growth of shoots was markedly reduced, and ionic alterations were prominently observed in the leaves when the seedlings were exposed to different concentrations (0, 100, and $150{\mu}M$) of $CuSO_4$. Using two-dimensional gels with silver staining, 643 differentially expressed protein spots (${\geq}1.5-fold$) were identified as either significantly increased or reduced in abundance. Of these spots, a total of 24 protein spots (${\geq}1.5-fold$) from Cu-exposed sorghum leaves were successfully analyzed by MALDI-TOF-TOF mass spectrometry. Of the 24 differentially expressed proteins from Cu-exposed sorghum leaves, a total of 13 proteins were up-regulated, and 11 proteins were down-regulated. The abundance of most identified protein species, which function in carbohydrate metabolism, stress defense, and protein translation, was significantly enhanced, while that of another protein species involved in energy metabolism, photosynthesis and growth and development were severely reduced. The resulting differences in protein expression patterns together with related morpho-physiological processes suggested that these results could help to elucidate plant adaptation to Cu stress and provide insights into the molecular mechanisms of Cu responses in $C_4$ plants. The over-expression of GAPDH plays a significant role in assisting Sorghum bicolor to attenuate the adverse effects of oxidative stress caused by Cu, and the proteins involved in resistance to stress helped the sorghum plants to tolerate high levels of Cu.