• Asian-Australasian Journal of Animal Sciences
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• 제31권3호
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• pp.363-368
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• 2018

Objective: The objective of the study was to determine the effect of fermented spent coffee ground (FSCG) on nutrient digestibility and nitrogen utilization in sheep. Methods: Fermentation of spent coffee ground (SCG) was conducted using Lactobacillus plantrum. Fermentation was performed at moisture content of 70% and temperature of $39^{\circ}C$ with anaerobic air tension for 48 h. Four adult rams (initial body weight = $56.8{\pm}0.4kg$) were housed in a respiration-metabolism chamber and the treatments were: i) control (Basal diet; 0% SCG or FSCG), ii) 10% level of SCG, iii) 10% level of FSCG, and iv) 20% level of FSCG in $4{\times}4$ Latin square design. Each dietary experiment period lasted for 18-d with a 14-d of adaptation period and a 4-d of sample collection period. Results: In SCG fermentation experimental result, acid detergent insoluble nitrogen (ADIN) concentration of FSCG (64.5% of total N) was lower than that of non-fermented SCG (78.8% of total N). Digestibility of dry matter and organic matter was similar among treatment groups. Although crude protein (CP) digestibility of the control was greater than FSCG groups (p<0.05), the 10% FSCG group showed greater CP digestibility and nitrogen retention than non-fermented 10% SCG group (p<0.05). Body weight gain and average daily gain were linearly decreased with increasing FSCG feeding level (p<0.05). When the feeding level of FSCG was increased, water intake was linearly increased (p<0.05). With an increasing FSCG level, dry matter intake did not differ among groups, although the gain to feed ratio tended to decrease with increasing level of FSCG (p<0.10). Conclusion: Microbial fermentation of SCG can improve protein digestibility, thereby increasing CP digestibility and nitrogen utilization in sheep. Fermentation using microorganisms in feed ingredients with low digestibility could have a positive effect on improving the quality of raw feed.

• 한국토양비료학회지
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• 제46권6호
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• pp.445-451
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• 2013

We researched nitrogen and green manure yield of crotalaria by seeding rate; 50, 60, 70, 80, 90 kg $ha^{-1}$ in upland soil to find out crotalaria's optimal seeding rate. Crotalaria's plant height and number of leaves increased when the harvest time was later regardless of its seeding rate. Its nitrogen content of above-ground part was 19.8 g $ha^{-1}$, and C/N ratio was 22.5. The highest nitrogen content (50.3 g $ha^{-1}$) was found in flowers part, followed by its leaves, roots and stems. The green manure yields of crotalaria increased when the harvest time was later. The green manure yield of crotalaria was biggest in 50kg $ha^{-1}$ which was low in seeding rate. It tended to decrease when the seeding rate was higher, and the nitrogen yield had the same tendency. Therefore, the appropriate seeding rate was 50kg $ha^{-1}$ and the time for application to soil was considered to be the flowering stage.

• Journal of the Korean Wood Science and Technology
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• 제38권2호
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• pp.124-134
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• 2010

This study was performed to evaluate the efficiency of using softwood as the sawdust medium for Lentinula edodes cultivation, effect of nutrient on the mycelial growth, spawning, the mushroom yield, and quality. The nitrogen nutrition significantly enhanced the mycelial growth of L. edodes. The glutamic acid in the L. leptolepis and P. koraiensis, and asparagine in the P. densiflora were appeared to slight increase in the mycelial growth. The vegetable oil showed very effective on the mycelial growth in the P. koraiensis sawdust medium. Carbon/nitrogen ratio of all the test was reduced after mycelial growth. The mycelial growth was exclusively dependent on reduction of carbon. The mushroom yield (32.7%) of the P. densiflora sawdust medium (carbon source: 3% active carbon, nitrogen source: 0.4% asparagines) was the best in mushroom production of L. edodes, followed by the Q. variabilis sawdust (35.4%) of the control medium. The diameter of mushroom cap was obtained from the P. densiflora sawdust (carbon source: 3% sucrose, nitrogen source: 0.4% potassium nitrate) and P. koraiensis sawdust (carbon source: 3% sucrose, nitrogen source: 0.4% potassium nitrate), and the P. koraiensis sawdust (carbon source: 3% xylose, nitrogen source: 0.4% glutamic acid, supplement: 0.05% amino acid), with values 71.5 mm, 71.5 mm and 72.1 mm, respectively. In the polypropylene bag cultivation, the weight losses of the block medium gradually increased for 80 days in the dark (13.8~16.8%) and then became stable in the range of 20.7~25.8%.

• 한국물환경학회지
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• 제23권5호
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• pp.607-612
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• 2007

In this study, we investigated the variations of the kinetic coefficients and Chemical Oxygen Demand (COD), N and P mass used for assimilation of a sequencing batch reactor (SBR) system with the variation of SRTs; SRTs of 7.5, 10.0, 12.5, 15.0 and 20.0 days were tested in one cycle of SBR operation to determine the optimum conditions for the operation of the SBR and estimate its COD, nitrogen and phosphorus removal efficiencies. The SBR system was operated under the conditions as follows: an operation time of 6 hours per cycle, a hydraulic retention time (HRT) of 12 hours, an influent COD loading of $0.4kg/m^3/day$, and an influent nitrogen loading of $0.068kgT-N/m^3/day$. The yield coefficient (Y) and decay rate coefficient ($k_d$) were estimated to be 0.4198 kgMLVSS/kgCOD and $0.0107day^{-1}$ by calculating the removal rate of substrate according to the variation of SRT. Considering total nitrogen amount removed by sludge waste process, eliminated by denitrification, and in clarified water effluent with reference to 150 mg/cycle of influent nitrogen amount, the percentage of nitrogen mass balance from the ratio of the nitrogen amount in effluent (N output) to that in influent (N input) for Runs 1~5 were 95.5, 97.0, 95.5, 99.5, and 95.5%, respectively, which is well accounted for, with mass balances close to 100%.

• Composites Research
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• 제17권6호
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• pp.44-51
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• 2004

에폭시 경화계에서 말단 관능기가 같은 선형아민 경화제의 주쇄에 포함된 에틸기에 결합된 질소원자 개수가 반응특성 및 열적, 기계적특성에 미치는 영향을 알아보기 위하여, 빈용 에폭시수지인 DCEBF (diglycidyl ether of bisphenol F)를 DETA (diethylenetriamine), TETA (triethylenetetraamine) 그리고 TEPA (tetraethylenepentaamine)와 1:1 당량비로 경화하였다. 이 연구에서 DGEBF/아민계에서 경화제 주쇄의 질소원자 거수에 의하여 반응특성 및 열적성질, 기계적특성에 중대하게 영향을 미쳤다. 즉, 주쇄의 질소원자 개수가 작을수록 반응열이 많고 최대발열온도가 낮아졌다. 경화물의 경우 밀도와 최대반응전환률은 주쇄의 질소원자 개수와는 큰 관계가 없으나, 굴곡탄성률과 인장탄성률은 주쇄의 질소원자 개수가 작을 수록 크다. 그 외의 열안정성, 부피수축률(%), 유리전이온도, 인장강도, 굴곡강도는 주쇄의 질소원자 개수와는 일견 무관한 불규칙한 경향을 보인다. 이는 최대반응전환률(%)의 차이가 이러한 특성에 영향을 미치는 것을 나타낸다.

• Asian-Australasian Journal of Animal Sciences
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• 제11권6호
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• pp.697-701
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• 1998

In order to improve silage quality and utilization of napier grass (Pennisetum purpureum Schum.) by goats, the grass was ensiled with molasses (MOL) and/or defatted rice bran (DRB). Napier grass was harvested at the growing stage in July and cut into 3 cm length. The grass was mixed with 4% MOL and/or 15% DRB, ensiled 15 kg each into plastic bags and stored for 9 months. Dry matter content of the silage ensiled with MOL (MOL-silage) was 13.4%, but increased to 20% with DRB addition. The addition of MOL decreased pH value and ammonia nitrogen content, but increased lactic acid content. MOL-silage contained about 6% spoilage, but addition of DRB decreased spoilage to less than 1%. Goats were fed the silage at a level of 2.25% (DM basis) of their body weight. Goats fed DRB- or MOL/DRB-silages maintained nitrogen retention, but goats fed MOL-silage did not. The rumen fluid of goats fed DRB-silage tended to be higher in acetic acid and lower in propionic acid than those fed the other silages. Ammonia in the rumen fluids, urea nitrogen in the blood and the urinary nitrogen excretion were the lowest in goats fed MOL/DRB-silage. As the result, the ratio of retained nitrogen to nitrogen intake was the highest in goats fed MOL/DRB-silage. In conclusion, addition of DRB to napier grass increased DM of silage and decreased the volume of spoilage. The combination of MOL and DRB can improve the fermentation quality and thus enhance the utilization of the silage by goats, more than the MOL or DRB being as a single treatment.

• 한국응용곤충학회지
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• 제9권1호
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• pp.15-20
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• 1970

수도품종명 도열병 저항성 차이와 도체내 성분과의 관계를 구명코저 저항성 품종, 중간정도 품종, 감수성인 품종의 실소 및 당 함량을 비교한 결과를 요약하면 다음과 같다. 1) 전질소, 전당 함량은 저항성인 품종이 감수성인 품종에 비해 전질소는 적고 전당은 많았다. 따라서 C/N 률은 저항성 품종이 감수성인 품종에 비해 높았다. 2) Free amino acid에 있어서는 저항성인 품종이 감수성인 품종에 비해 Glutamine, Valine 그리고 Leucine 과 Iso-leucine함량이 많았다. 3) 각종당액에서 전분합성은 저항성인 품종이 감수성인 품종에 비해 Fructose, Glucose에서는 높았고 Sucrose에서는 낮았으나 Indica type로 저항성인 Zenith에서는 오히려 전분합성이 감수성인 다다조 보다 떨어졌다. 4) 질소비료를 증시하면 전질소함량은 보비보다 증가하는데 그 증가율은 저항성인 품종에서 낮은 경향이었다. 전당은 분벽초기에 감소되며 그 감소율은 저항성인 품종이 더 떨어졌고 분벽최성기에는 오히려 증가하였는데 그 증가율은 저항성인 품종이 높은 경향이었다.

• Corrosion Science and Technology
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• 제9권1호
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• pp.20-28
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• 2010

According to the bipolar model, ion selectivity of some species in the passive film is important factor to control the passivation. An increase of cation selectivity of outer layer of the passive film can stabilize the film and improves the corrosion resistance. Therefore, the formation and roles of ionic species in the passive film should be elucidated. In this work, two types of solution (hydrochloric or sulfuric acid) were used to test high N and Mo-bearing stainless steels. The objective of this work was to investigate the formation of oxyanions in the passive film and the roles of oxyanions in passivation of stainless steel. Nitrogen exists as atomic nitrogen, nitric oxide, nitro-oxyanions (${NO_x}^-$), and N-H species, not nitride in the passive film. Because of its high mobility, the enriched atomic nitrogen can act as a reservoir. The formation of N-H species buffers the film pH and facilitates the formation of oxyanions in the film. ${NO_x}^-$ species improve the cation selectivity of the film, increasing the oxide content and film density. ${NO_x}^-$ acts similar to a strong inhibitor both in the passive film and at active sites. This facilitates the formation of chromium oxide. Also, ${NO_x}^-$ can make more molybdate and nitric oxide by reacting with Mo. The role of Mo addition on the passivation characteristics of stainless steel may differ with the test environment. Mo exists as metallic molybdenum, molybdenum oxide, and molybdate and the latter facilitates the oxide formation. When nitrogen and molybdenum coexist in stainless steel, corrosion resistance in chloride solutions is drastically increased. This synergistic effect of N and Mo in a chloride solution is mainly due to the formation of nitro-oxyanions and molybdate ion. Oxyanions can be formed by a 'solid state reaction' in the passive film, resulting in the formation of more molybdate and nitric oxide. These oxyanions improve the cation selectivity of the outer layer and form more oxide and increase the amount of chromium oxide and the ratio of $Cr_2O_3/Cr(OH)_3$ and make the film stable and dense.

• 한국습지학회지
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• 제8권3호
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• pp.39-49
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• 2006

Seasonal biomass and carbon, nitrogen contents change of marsh club-rush (Schoenoplectus trigueter) was investigated in Nakdong river estuary, located near Busan, Korea. New shoot of S. trigueter sprouted from tuber in April and fast growth season was followed until mature in August. Mature lengths of shoot and root were 60 and 9.4 cm, respectively. The increase of biomass showed similar seasonal trends with length. Mature biomass were $3.5gind^{-1}$ in wet weight and $0.6gind^{-1}$ in dry weight. The biomass of S. trigueter in areal basis was also highest during July and August ($186gDWm^{-2}$). The shoot of S. trigueter was disappeared in October from the ground but the biomass of shoot was maintained as a form of detritus in sediment. The amount of S. trigueter detritus was about 30~50% of the biomass in August. During winter, the amount of detritus decreased with time but the biomass of root+tuber remained same, implying the root+tuber part is alive. The net productivity of S. trigueter estimated from biomass change were $538gDWm^{-2}yr^{-1}$, $240g-Cm^{-2}yr^{-1}$, $8.2g-Nm^{-2}yr^{-1}$ in dry weight, carbon and nitrogen equivalent respectively. During winter, carbon to nitrogen ratio in detritus increased implying the preferred remineralization of nitrogen during microbial degradation.

• 한국지하수토양환경학회지:지하수토양환경
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• 제26권4호
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• pp.8-19
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• 2021

In this study, the evaluation standard for nitrate nitrogen contamination degree (WELCUP) was established using six factors that influence the groundwater quality in Jeju Island. To do this, weightings, ranges, and ratings were assigned for each factor and the relative possibility of nitrate nitrogen contamination degree was evaluated using WELCUP index for each well. As a result of calculating the WELCUP index using groundwater quality data of 5,112 wells in Jeju Island for 27 years (1993-2019), all 61 wells with the WELCUP index value higher than 100 are distributed in Daejung and Hangyung watershed with relatively large area of farmland in Jeju Island. In particular, as the ratio of private wells is more than 64%, it is necessary that systematic management is needed for private wells in terms of nitrate nitrogen contamination. Consequently, based on the results of applying the WELCUP evaluation standard, it is necessary to select the prioritization of nitrate nitrogen contamination pathways project for groundwater wells in Jeju Island.