• Asian-Australasian Journal of Animal Sciences
• /
• 제33권2호
• /
• pp.245-253
• /
• 2020

Objective: To develop the fermentation quality and chemical composition of alfalfa (Medicago sativa Lam.) silage, plants were inoculated with different lactic acid bacteria (LAB) strains at field 24 hours before harvest. Methods: The treatment groups were as follow: silage without additive as a control and inoculated with each strains of Lactobacillus brevis (LS-55-2-2), Leuconostoc citerum (L. citerum; L-70-6-1), Lactobacillus bifermentans (L. bifermentans; LS-65-2-1), Lactobacillus plantarum (L. plantarum; LS-3-3) and L. plantarum (LS-72-2). All the silages were stored at 25℃. Parameters such as pH, microorganism and volatile fatty acid contents, crude protein, neutral detergent fiber, acid detergent fiber, net gas, metabolizable energy, organic matter digestibility, dry matter intake and relative feed value were measured to determine fermentation quality, chemical compositions and relative feed value of alfalfa silages. Results: Significant differences were found among the control and treated groups in terms of pH and microorganism contents at all opening times and crude protein, net gas, metabolizable energy and organic matter digestibility of final silage. The pH values ranged from 4.70 to 5.52 for all treatments and control silage had the highest value of overall treatments at T₇₅d silages. Volatile fatty acid of silages was not influenced significantly by inoculations. However, lactic acid content of L. bifermentans (LS-65-2-1) was higher than the other treatments. The highest metabolizable energy and organic matter digestibility were recorded from L. citerum (L-70-6-1) inoculation. In addition, no significant differences were found among treatments in terms of neutral detergent fiber, acid detergent fiber, dry matter intake and relative feed value. Conclusion: Among the treated LAB isolates, L. bifermentans came into prominence especially in terms of organic acid composition and quality characters of silages.

• 펄프종이기술
• /
• 제42권2호
• /
• pp.53-60
• /
• 2010

Kudzu vine (Pueraria lobata) is a perennial plant and spreads all around in South Korea. Recently the use of leaves, stems and roots of kudzu vine has been investigated in many fields. However, the research on kudzu fibers has not been performed in korean pulp and paper industry. As the stems and roots of kudzu were estimated to contain cellulosic fibers, the possibility of producing a raw material from kudzu fibers in pulp and paper mills was investigated in this study. The stems and roots of kudzu were collected in woods, and then the chemical composition and ash contents was measured. To acquire kudzu pulp, kraft pulping and bleaching of kudzu roots were carried out sequently. After making kudzu pulp, freeness and fiber length were measured, and handsheets was also prepared with kudzu pulp and the properties of handsheets were determined. Consequently, kudzu fibers have lower holocellulose contents than wood fibers and other non-wood fibers. Average fiber length is shorter than that of Sw-BKP, but shows the same level as that of Hw-BKP. The handsheet made from kudzu pulp shows the bulkier structure than those made from Hw-BKP and Sw-BKP.

• Korean Chemical Engineering Research
• /
• 제49권2호
• /
• pp.218-223
• /
• 2011

범용 PAN계 탄소섬유를 $1,500^{\circ}C$까지 열처리한 후 탄소함량, 결정화도, 결정크기를 분석하고 이들의 변화에 따른 표면의 발열특성을 조사하였다. PAN계 탄소섬유의 결정화도, 결정크기는 열처리 온도가 1,000에서 $1500^{\circ}C$로 증가하는 동안 각각 37.08에서 53.69%, 1.62에서 1.82 nm로 증가하였고, 탄소섬유의 초기표면발열온도는 결정화도, 결정크기가 증가할수록 1차식으로 비례하여 증가하였다. 따라서 탄소섬유의 결정화도와 결정크기를 표면발열온도의 상승을 측정하여 간접적으로 신속하게 추정할 수 있게 되었다.

• 한국식품과학회지
• /
• 제25권4호
• /
• pp.299-306
• /
• 1993

본 연구에서는 일부 한국산 식품의 식이섬유 함량을 Englyst 등의 비색법과 gas chromatography 방법에 의한 비전분 다당류 분석에 의하여 측정하였다. Gas chromatography 방법에 의한 비전분다당류의 측정 결과, 곡류와 두류의 비전분다당류에서는 glucose와 5탄당인 arabinose 및 xylose, 미역, 다시마와 채소류의 불용성 비전분 다당류에서는 glucose, 수용성 비전분 다당류에는 uronic acid가 주요당이었다. 또한, 김의 불용성 및 수용성 비전분 다당류에는 galactose가 상당량 함유되어 있었다. Englyst와 Cummings의 비색법(x)과 gas chromatography 방법(y)에 의한 비전분다당류 값의 상관관계는 곡류, 두류 및 채소류의 식품군에서 y=1.01x-0.52(r=0.997, n=9)로 좋은 일치를 보여주었다. 한편 AOAC 공정법에 의한 총 식이섬유 함량(x)과 Englyst와 Cummings의 gas chromatography 방법에 의한 비전분 다당류 함량(y)의 상관관계 y=0.55x+2.14(r=0.786, n=12)로서 상관관계가 낮았으나, AOAC 공정법에 의한 총 식이섬유 함량(x)과 비전분 다당류 함량에 lignin 함량을 합한 값(y)의 상관관계는 y=0.68x+0.64(r=0.903, n=12)이었다.

• Advances in Computational Design
• /
• 제2권3호
• /
• pp.225-240
• /
• 2017

This paper presents the application of multiple linear regression (MLR) and artificial neural network (ANN) techniques for developing the models to predict the unconfined compressive strength (UCS) and Brazilian tensile strength (BTS) of the fiber reinforced cement stabilized fly ash mixes. UCS and BTS is a highly nonlinear function of its constituents, thereby, making its modeling and prediction a difficult task. To establish relationship between the independent and dependent variables, a computational technique like ANN is employed which provides an efficient and easy approach to model the complex and nonlinear relationship. The data generated in the laboratory through systematic experimental programme for evaluating UCS and BTS of fiber reinforced cement fly ash mixes with respect to 7, 14 and 28 days' curing is used for development of the MLR and ANN model. The data used in the models is arranged in the format of four input parameters that cover the contents of cement and fibers along with maximum dry density (MDD) and optimum moisture contents (OMC), respectively and one dependent variable as unconfined compressive as well as Brazilian tensile strength. ANN models are trained and tested for various combinations of input and output data sets. Performance of networks is checked with the statistical error criteria of correlation coefficient (R), mean square error (MSE) and mean absolute error (MAE). It is observed that the ANN model predicts both, the unconfined compressive and Brazilian tensile, strength quite well in the form of R, RMSE and MAE. This study shows that as an alternative to classical modeling techniques, ANN approach can be used accurately for predicting the unconfined compressive strength and Brazilian tensile strength of fiber reinforced cement stabilized fly ash mixes.

• Asian-Australasian Journal of Animal Sciences
• /
• 제19권3호
• /
• pp.356-362
• /
• 2006

This study aimed to assess the effects of neutral detergent fiber (NDF) from rice straw on blood metabolites and productivity of dairy cows in the tropics. Eight Holstein ${\times}$ indigenous (75-87.5% Holstein) were randomly allocated to dietary treatments according to a double $4{\times}4$ Latin square design. Contents of roughage NDF from rice straw were 12.8, 14.8, 16.8 and 18.8% dry matter (DM) and concentrate NDF content was 10.2% DM, so that levels of dietary NDF were 23, 25, 27 and 29% DM. Dietary treatments were isonitrogenous and isocaloric diets. The average maximum and minimum temperature humidity index during the experimental period were 85.6 and 76.9, respectively. Plasma glucose (p<0.05), dry matter intake and 4% fat corrected milk (p<0.01) decreased with increasing contents of roughage NDF from rice straw, while rectal temperature, serum urea, cortisol, low density lipoprotein-cholesterol (p<0.05), serum total protein and ${\beta}$-hydroxybutyrate (p<0.01) increased. Serum triglyceride, total cholesterol and high density lipoprotein-cholesterol were not affected (p>0.05). Decreased rectal temperature and concentrations of serum cortisol were associated with decreasing levels of ${\beta}$-hydroxybutyrate and serum urea, but with increased concentrations of plasma glucose, DMI and 4% fat corrected milk indicating that lactating cows fed lower fiber diets were in lower oxidative stress. Therefore higher intake and metabolic efficiency in dairy cows fed diets lower in roughage NDF from rice straw would be of an advantage in productive systems under tropical conditions.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2007년도 추계 학술논문 발표대회
• /
• pp.71-74
• /
• 2007

With the changes of times the building materials tend to extend the demand for application under the special environment. Since high-ductile mortar is developed, the building materials show excellent performance like toughness, compression, tensile, and bending, etc. in the general concrete from the existing brittle point. And, recently they are widely used as repairing and reinforcing materials both at home and abroad because they are recognized as excellence like durability and fire-resistance. However, it is in a situation of creating problems in durability because it frequently happened deterioration of buildings that have already repaired and reinforced at a time when it requires reconstruction of recently deteriorated construction structure recently. Therefore, in this study improved with a more repair Material development and reinforcement of the second high-ductile mortar products for a variety of basic materials were presented want, research plans used include traditional repair materials and the newly developed PCM (polymer cement mortar) structural reinforcement type indicated that comparison. PCM analysis in order to present a rate depending on the types fiber 0, 1.2 and 2.0(%) at three levels and mixture water according to ratios of weight to Plain in the 2.0 and 1.85(kg) at two levels is set, the results were as follows. 1) This study has shown that PCM had excellent strain hardening behavior at the same time that the bending stress increased according to the fiber contents. 2) This study has shown that it had the durability performance due to the high substance transmission according to the fiber contents.

• 폴리머
• /
• 제33권6호
• /
• pp.530-536
• /
• 2009

고리지방족 에폭시와 산무수물 경화제계에 탄소단섬유(SCF)와 유리단섬유(SGF)를 첨가하여 복합재를 제조한 다음 이들의 열적/기계적 특성을 조사하였다. 열기계분석법으로 측정된 열팽창계수(CTE)의 감소 효과를 보면 낮은 단섬유 함량에서는 두 섬유가 거의 비슷하나, 함량이 증가하면 SCF가 SGF에 비해 훨씬 효과적이었다. SCF 강화 복합재에 대한 CTE 실험값을 이론식에 적용해 본 결과 함량이 낮을 때는 혼합법칙(mixture rule)에 잘 맞으며, 함량이 높아지면 Craft-Christensen 식에 근접하였다. 또한, 유리상($30^{\circ}C$과 고무상($180^{\circ}C$)에서의 저장탄성률은 단섬유를 첨가하였을 때 크게 증가하였다. 전자주사현미경(SEM)으로 파단면을 관찰하여본 결과 이와 같은 결과는 단섬유와 에폭시 매트릭스간의 계면접착력과 밀접한 관계가 있음을 알 수 있었다.

• 한국콘텐츠학회논문지
• /
• 제18권12호
• /
• pp.291-298
• /
• 2018

에너지 설비에 대한 공급업체 선정 문제는 화학섬유 기업의 생산 원가를 결정하는 전략적으로 매우 중요한 의사결정 문제 중의 하나다. 본 연구의 목적은 에너지 설비 공급 업체 선정을 위한 합리적인 방법을 제시하는 데 있다. 이를 위해 설비 공급 업체 선정을 위한 평가 요소를 선정하고, 네트워크 의사결정 분석(Analytic Network Process) 모형을 활용하여 계량 및 비계량적 평가 요소들에 대한 가중치를 도출하였다. 이 방법을 통해 설비 공급 업체 선정 평가 요소 간의 상호 연관성을 반영한 보다 정확한 가중치를 산정하고자 하였으며, 실제 에너지 공급 설비 대안들에 대한 우선순위를 산정한 결과 태양광 설비를 가장 적합한 대안으로 선정하고, 이 과정과 결과를 통해 제시된 방법의 타당성을 확인할 수 있었다.

• Journal of the Korean Wood Science and Technology
• /
• 제32권2호
• /
• pp.26-32
• /
• 2004

고추줄기의 화학 조성분과 lignin 화학구조를 분석하였고, 알칼리 증해 적성과 pulp의 섬유장을 측정한 후 목재와 비교하였다. 고추줄기의 화학 조성은 목재에 비해 추출성분, 회분함량이 높았으며, Klason lignin은 침·활엽수의 중간 정도의 함량을 나타내었다. 고추줄기 Klason lignin의 원소분석은 자작나무의 Klason lignin과 비교하여 탄소와 수소는 유사한 양으로 나타난 반면 산소의 함량은 낮게 나타나고 질소의 함량은 비교적 높게 나타났다. 니트로벤젠 산화분해는 S/V가 1보다 낮으므로 고추줄기 리그닌은 vanillin의 양이 syringaldehyde보다 상당히 많은 침엽수 리그닌과 유사한 구조를 보이는 것으로 추정되었다. 고추줄기의 알칼리 증해 적성은 활성알칼리 20%, 액비 1:7의 조건하에서 0.2%-Anthraquinone을 첨가하여 증해하는 것이 리그닌 함량과 수율면에서 최적 증해 조건이었다. 고추줄기 pulp의 섬유장은 약 0.47 mm로 보통 목재섬유에 비해서 매우 짧아 고추대 만으로 제지용 pulp를 제조하는 것보다는 목재 pulp와 혼합하여 사용하거나 비교적 단섬유가 많이 필요한 특수한 용도로 사용 가능하다.