• 한국포장학회지
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• 제14권2호
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• pp.81-88
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• 2008

There are increasing public concerns that the disposal of most synthetic carbon-based plastics is a great threat to the environment. These have led to intensive research and development of degradable plastics, such as biodegradable plastics, photodegradable plastics, and multi-degradable plastics. Although these degradable plastics may not completely replace common synthetic plastics, these minimize environmental impacts caused by non degradable plastics. Photodegradable plastics are synthetic polymers into which have been incorporated copolymers or light-sensitive additives to weaken the structural bonds in polymer chains when exposed to UV radiation. A better understanding of photodegradable plastics, which also play an important role in the degradation of multi-degradable plastics, will expand the usage of degradable plastics. The aim of present article is to review the formation, degradation mechanism and properties of photodegradable plastics.

• 한국토양비료학회지
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• 제49권4호
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• pp.375-380
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• 2016

The use of polyethylene film has a problem such as increasing rural environmental contamination, collection costs and farmers' workload. The objective of this study was to evaluate bio-degradable films in terms of yield of maize and soil environment. Treatments were bio-degradable film A (BDF A), bio-degradable film B (BDF B), high density polyethylene (HDPE), and non-mulched (NM) soil. Daily mean values of soil temperature (10 cm depth) under BDF A, BDF B, and HDPE were higher than in NM soil by 2.2, 2.8, $3.1^{\circ}C$ respectively. In the mulching cultivation of maize, bio-degradable film began to degrade from 50~60days after the planting. The degradation was much progressed in the harvest time and almost decomposed in the following spring. The weight of ear of maize was not shown significantly by mulching treatments. There were little changes of soil chemical properties for the bio-degradable film mulching. After using bio-degradable films, the contents of biomass-C and dehydrogenase activity increased from 92 to $137{\sim}147mg\;kg^{-1}$, and from 87 to $123{\sim}168mg\;kg^{-1}$ respectively.

• 한국환경과학회지
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• 제24권1호
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• pp.9-15
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• 2015

Sustainable and eco-friendly polymers, natural polymers, bio-based polymers, and degradable polyesters, are of growing interest because of environmental concerns associated with waste plastics and emissions of carbon dioxide from preparation of petroleum-based polymers. Degradable polymers, poly(butylene adipate-co-terephthalate) (PBAT), poly(propylene carbonate) (PPC), and poly(L-lactic acid) (PLLA), are related to reduction of carbon dioxide in processing. To improve a weak mechanical property of a degradable polymer, a blending method is widely used. This study was forced on the component separation of degradable polymer blends for effective recycling. The melt-mixed blend films in a specific solvent were separated by two layers. Each layer was analysed by FT-IR, DSC, and contact angle measurements. The results showed that each component in the PPC/PLLA and PPC/PBAT blends was successfully separated by a solvent.

• Asian-Australasian Journal of Animal Sciences
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• 제5권4호
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• pp.643-646
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• 1992

Role of low degradable protein in milk production of early lactating Murrah buffaloes has been studied in relation to energy status of test animals. Replacement of conventional concentrate mixture with low degradable cotton seed cake resulted in appreciable changes in circulatory transaminases and phosphatase levels. The enzymes viz. glutamate oxaloacetate and glutamate pyruvate transaminase and alkaline phosphatases increased with feeding of said cake indicating stress on hepatic tissue. Animals seemed to overcome stress by feeding enhanced levels of same protein along with improved feed intake, body weight and milk production.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2004년도 학술대회지
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• pp.367-371
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• 2004

Bio-degradable hydraulic oil using polyolester base oil is formulated for the applications of heavy duty hydraulic machineries. It has proved quality and market price competitiveness by assessment of reliability test in vehicle manufacturer and specific vehicle related institute. Contribution of bio-degradable oil keep the working environment clean and increase export competitiveness in European market. Leakage or waste of mineral types of hydraulic oils in heavy duty machineries causes pollution of river, ocean, underground water. Drinkable-water pollution is serious problem in Europe. In some European countries, using bio-degradable hydraulic oils become an obligation in heavy duty machineries. New product of bio-degradable oils satisfy the European regulations(OECD 302B) and shows excellent performance in compare with European products.

• Asian-Australasian Journal of Animal Sciences
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• 제30권5호
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• pp.653-659
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• 2017

Objective: This trial was performed to examine the effects of ruminally degradable starch (RDS) levels in total mixed ration (TMR) with low corn-based starch on the milk production, whole-tract nutrient digestibility and nitrogen balance in dairy cows. Methods: Eight multiparous Holstein cows (body weight [BW]: $717{\pm}63kg$; days in milk [DIM]: $169{\pm}29$) were assigned to a crossover design with two dietary treatments: a diet containing 62.3% ruminally degradable starch (% of total starch, low RDS) or 72.1% ruminally degradable starch (% of total starch, high RDS). Changes to the ruminally degradable levels were conducted by using either finely ground corn or steam-flaked corn as the starch component. Results: The results showed that dry matter intake, milk yield and composition in dairy cows were not affected by dietary treatments. The concentration of milk urea nitrogen was lower for cows fed high RDS TMR than low RDS TMR. The whole-tract apparent digestibility of neutral detergent fiber, acid detergent fiber and crude protein decreased, and that of starch increased for cows fed high RDS TMR over those fed low RDS TMR, with no dietary effect on the whole-tract apparent digestibility of dry matter and organic matter. The proportion of urinary N excretion in N intake was lower and that of fecal N excretion in N intake was higher for cows fed high RDS TMR than those fed low RDS TMR. The N secretion in milk and the retention of N were not influenced by the dietary treatments. Total purine derivative was similar in cows fed high RDS TMR and low RDS TMR. Consequently, estimated microbial N flow to the duodenum was similar in cows fed high RDS TMR and low RDS TMR. Conclusion: Results of this study show that ruminally degradable starch levels can influence whole-tract nutrient digestibility and nitrogen balance in dairy cows fed low corn-based starch diets, with no influence on performance.

• 한국작물학회지
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• 제56권2호
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• pp.113-118
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• 2011

작물의 멀칭재배에 활용이 가능한 생분해성 필름의 개발과 이용가능성을 검토하고자 수행한 결과는 다음과 같다. 1. 천연고분자를 이용한 생분해가 가능한 필름의 제조를 위해 벼 부산물인 왕겨와 쌀겨를 이용하여 생분해성 필름을 제조하였다. 2. 천연고분자를 이용하여 개발된 생분해성 필름의 기계적인 특성은 기존 멀칭필름과 비교해서 신장율은 낮으나 인장강도는 2배 이상 강함을 보였다. 그리고 파열점 비교에서도 멸칭필름은 뚜렷한 파열점이 존재하고 그 이후에는 같은 힘을 주어도 계속 늘어난 반면, 생분해성 필름은 서서히 늘어나며 점차 힘을 증가시켜야 늘어나는 특성을 보였다. 3. 생분해성 필름에 대한 유해성분 용출시험에서 중금속 들이 검출되지 않았고, 국내 친환경 인증 기준이 정하는 생분해성 수지의 함량기준에 충족하였다. 4. 작물을 이용한 토양 분해력 시험에서도 3 개월 이후에 서 대부분 분해됨을 보여 일반 농업 현장에 적용이 가능할 것으로 사료된다.

• 한국지반신소재학회논문집
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• 제12권1호
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• pp.29-38
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• 2013

본 논문에서는 생분해 배수재를 이용한 오염토양 정화기술의 현장적용성을 평가하기 위하여 생분해 배수재의 물리적 특성시험을 수행하였으며, 이를 이용한 현장실험을 통하여 중금속 오염토양의 정화효율을 분석하였다. 두 종류(실린더 코어형, 하모니카형)의 생분해 배수재에 대한 시험결과, 실린더 코어형 배수재의 경우, 한국산업규격 표준시방에서 제시하는 기준치를 모두 만족하였으며, 하모니카형 생분해성 배수재는 실린더 코어형 배수재에 비해 배수성능이 상당히 낮은 결과를 나타내었다. 또한 오염토양 복원시 사용한 세정제로는 자체독성이 적어 생태계에 미치는 영향을 최소화하며, 생물학적 재순환시스템과의 최적인 조건을 지니고 있는 시트르산(ctric acid)을 선정하여 중금속 중 Cd, Cu, Pb을 현장실험 대상 오염물질로 선정 후 실험을 수행하였다. 현장실험은 3가지 설치조건을 고려하여 정화효율을 분석하였으며, 반응물질이 도포된 생분해 배수재를 이용하여 세척제를 주입 추출을 동시에 수행한 경우가 복원효율이 가장 높은 것으로 평가되었다.

• Animal Bioscience
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• 제36권7호
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• pp.1044-1058
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• 2023

Objective: The objective of this study was to characterize physiochemical and nutrient profiles of feedstock and co-products from canola bio-oil processing that were impacted by source origin. The feedstocks and co-products (mash, pellet) were randomly collected from five different bio-oil processing plants with five different batches of samples in each bio-processing plant in Canada (CA) and China (CH). Methods: The detailed chemical composition, energy profile, total digestible nutrient (TDN), protein and carbohydrate subfractions, and their degradation and digestion (CNCPS6.5) were determined. Results: The results showed that TDN_1x was similar in meals between CA and CH. CH meals and feedstock had higher, truly digestible crude protein (tdCP) and neutral detergent fiber (tdNDF) than CA while CA had higher truly digestible non-fiber carbohydrate (tdNFC). The metabolizable energy (ME_3x), net energy (NE_Lp3x, NE_m3x, and NE_g3x) were similar in meals between CA and CH. No differences were observed in energy profile of seeds between CA and CH. The protein and carbohydrate subfractions of seeds within CH were similar. The results also showed that pelleting of meals affected protein sub-fractionation of CA meals, except rapidly degradable fractions (PB1), rumen degradable (RDPB1) and undegrdable PB1 (RUPB1), and intestinal digestible PB1 (DIGPB1). Canola meals were different in the soluble (PA2) and slowly degradable fractions (PB2) between CA and CH. The carbohydrate fractions of intermediately degradable fraction (CB2), slowly degradable fraction (CB3), and undegradable fraction (CC) were different among CH meals. CH presented higher soluble carbohydrate (CA4) and lower CB2, and CC than CA meals. Conclusion: The results indicated that although the seeds were similar within and between CA and CH, either oil-extraction process or meal pelleting seemed to have generated significantly different aspects in physiochemical and nutrient profiles in the meals. Nutritionists and producers need to regularly check nutritional value of meal mash and pellets for precision feeding.

• 펄프종이기술
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• 제29권1호
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• pp.43-51
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• 1997

The various culture conditions of Trichoderma viride(ATCC 3454) and Phanerochaete chrysosporium(ATCC 26921) with glucose-pepton medium, Mandels medium, YMG medium for wood degradable enzyme were examined. Mycellium of the two species grew profusely on glucose-pepton medium. Maximum fungal growth was observed about 10days. But CMCase, Fpase, laccase activity in the culture medium with glucose-pepton was not detected. When grown in fermenter culture using Mandels medium, Trichoderma viride produced CMCase and Fpase. Its CMCase activity was 0.15 lU/ml and Fpase activity was 0.3 IU/ml within about 4-6days. Phanerochaete chrysosporium grown in a YMG medium gave the best enzyme activity when they were grown under stationary culture with an atmosphere of 100% oxygen. Levels of laccase activity of 3.0 mull were achieved in stationary culture under 100% oxygen. The enzyme condensation by ultrafiltration method caused a 2-fold(cellulase) and 6-fold(laccase) as compared to control activity.