• Asian-Australasian Journal of Animal Sciences
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• 제26권9호
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• pp.1304-1312
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• 2013

The effects of storage period and aerobic deterioration on the bacterial community were examined in Italian ryegrass (IR), guinea grass (GG), and whole-crop maize (WM) silages. Direct-cut forages were stored in a laboratory silo for 3, 7, 14, 28, 56, and 120 d without any additives; live counts, content of fermentation products, and characteristics of the bacterial community were determined. 2,3-Butanediol, acetic acid, and lactic acid were the dominant fermentation products in the IR, GG, and WM silages, respectively. The acetic acid content increased as a result of prolonged ensiling, regardless of the type of silage crop, and the changes were distinctively visible from the beginning of GG ensiling. Pantoea agglomerans, Rahnella aquatilis, and Enterobacter sp. were the major bacteria in the IR silage, indicating that alcoholic fermentation may be due to the activity of enterobacteria. Staphylococcus sciuri and Bacillus pumilus were detected when IR silage was spoiled, whereas between aerobically stable and unstable silages, no differences were seen in the bacterial community at silo opening. Lactococcus lactis was a representative bacterium, although acetic acid was the major fermentation product in the GG silage. Lactobacillus plantarum, Lactobacillus brevis, and Morganella morganii were suggested to be associated with the increase in acetic acid due to prolonged storage. Enterobacter cloacae appeared when the GG silage was spoiled. In the WM silage, no distinctive changes due to prolonged ensiling were seen in the bacterial community. Throughout the ensiling, Weissella paramesenteroides, Weissella confusa, and Klebsiella pneumoniae were present in addition to L. plantarum, L. brevis, and L. lactis. Upon deterioration, Acetobacter pasteurianus, Klebsiella variicola, Enterobacter hormaechei, and Bacillus gibsonii were detected. These results demonstrate the diverse bacterial community that evolves during ensiling and aerobic spoilage of IR, GG, and WM silages.

• Journal of Microbiology and Biotechnology
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• 제20권3호
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• pp.602-608
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• 2010

An atrazine-degrading bacterium, strain KU001, was obtained from a sugarcane field at the Cane and Sugar Research and Development Center at the Kasetsart University, Kamphaeng Saen Campus, Thailand. Strain KU001 had a rod-to-coccus morphological cycle during growth. Biolog carbon source analysis indicated that the isolated bacterium was Arthrobacter histidinolovorans. Sequence analysis of the PCR product indicated that the 16S rRNA gene in strain KU001 was 99% identical to the same region in Arthrobacter sp. The atrazine degradation pathway in strain KU001 consisted of the catabolic genes trzN, atzB, and atzC. Strain KU001 was able to use atrazine as a sole nitrogen source for growth, and surprisingly, atrazine degradation was not inhibited in cells grown on ammonium, nitrate, or urea, as compared with cells cultivated on growth-limiting nitrogen sources. During the atrazine degradation process, the supplementation of nitrate completely inhibited atrazine degradation activity in strain KU001, whereas ammonium and urea had no effect on atrazine degradation activity. The addition of strain KU001 to sterile or nonsterile soils resulted in the disappearance of atrazine at a rate that was 4- to 5-fold more than that achieved by the indigenous microbial community. The addition of citrate to soils resulted in enhanced atrazine degradation, where 80% of atrazine disappeared within one day following nutrient supplementation.

• Journal of Biosystems Engineering
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• 제25권1호
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• pp.39-46
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• 2000

This work was conducted to study the operating characteristics of a grinding system designed to obtain fine rice husk ash powder. To find better utilizing of rice husk, a valuable by-product from rice production, once the rice husk was incinerated and the thermal energy was recovered from the furnace, the ash was fed and pulverized in the grinding system resulting a fine powder to be used as a supplementary adding material to the portland cement manufacturing . The rice husk ash grinding system consisted of a high speed centrifugal fan for the preliminary coarse milling and a dry-type stirred ball mill for the subsequent fine grinding . Total grinding time 9 5, 15, 30, 45 min), impeller speed (250, 500, 750 rpm) , and mixed ratio (4.8, 7.9, 14.9) were three operating factors examined for the performance of a stirred ball mill used for the fine grinding of ash. With the stirred ball mill used in this study, the minimum attianable mean diameter of rice husk ash powder appeared to be 2 ${\mu}{\textrm}{m}$. During the find grinding, the difference in specific surface area of powder showed an increase and the grinding energy efficiency decreased with the increase in total grinding time, impeller speed ,and mixed ratio. For the operating conditions employed , the resulting mean diameter of fine ash powder, specific energy input, and grinding energy efficiency were in the range of 1.79 --16.04${\mu}{\textrm}{m}$, 0.072-5.226kWh/kg, an d1.11-12.15$m^2$/Wh, respectively. Grinding time of 30 min , impeller speed of 750 rpm, and mixed ratio of 4.8 were chosen as the best operating conditions of the stirred ball mill for fine grinding . At these conditions, mean particle diameter of the fine ash, grinding energy efficiency, grinding throughtput, and specific energy input were 2.73${\mu}{\textrm}{m}$, 3.95$m^2$/Wh, 0.25kg/h, and 1.22kWh/kg, respectively.

• Journal of Biosystems Engineering
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• 제25권2호
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• pp.115-122
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• 2000

This study was performed to develop a prototype continuous flow ginseng dryer with which better product quality and lower drying energy consumption could be achieved compared with conventional ginseng dryers. A dryer having both far infrared ray (IR) and heated-air as the drying energy sources was designed and fabricated . Dryer performance was studied by examining energy efficiencies and dryer performance evaluation indices (DPEI) during the drying tests of medium-sized four year ginseng roots with IR radiating plate temperature and drying air temperature in the range of 80-12$0^{\circ}C$ and 22-5$0^{\circ}C$, respectively. The DPEI of IR /heated -air combined drying was 1/3 of that of the conventional heated-air drying when ginseng were dried to the same final moisture ratio. When ginsengs were dried for 12 hours in the prototype IR/heated-air combination dryer, a linear relationship was found to exist between final moisture ratio and ginseng temperature. As the drying progressed, drying air temperature inside the dryer was nearly constant but ginseng temperature was drastically increased during the first two hours and gradually increased thereafter until the end of drying. With the prototype Ir/heated-air combination dryer, the drying rate changed little but the energy efficiency increased proportionally when the amount of ginseng to be dried increased. Drying capacity, energy efficiency, and DPEI of the prototype IR/heated-air combination ginseng dryer were estimated to 1.500 roots, 65% and 3.800kJ/kg-water , respectively.

• Journal of Biosystems Engineering
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• 제34권4호
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• pp.286-294
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• 2009

A high prevalence of protected horticulture farmer's work-related musculo-skeletal disorders (MSDs) have been reported in precedent studies. One of the tasks required ergonomic intervention to reduce the musculo-skeletal risks is the task of product transporting. The purpose of this study is to evaluate quantitatively the spinal load of operator using manual vehicles to predict and prevent musculo-skeletal risks. Spinal load in operators using 4 kinds of manual vehicle were analyzed. Before evaluating spinal load on operator using the manual vehicles by bio-mechanical approach, it is needed to validate human model. In this study, ADAMS LifeMOD human model shows satisfactory results, comparing with already validated model's results or measured results. While Operators pushed the manual vehicles(wheelbarrow, Trolley, 2 wheel cart, and 4 wheel cart) contained loads that were 0 N and 800 N, their spinal loads(compression force, shear force) were evaluated. The compression force demonstrated under the NIOSH action limits - 3410N - for all 4 manual vehicle's operators(McGill 1997; Marras 2000). However, the lateral shear force demonstrated over the University of Waterloo - 500N - for all 3 manual vehicle's operators except 4Wheel cart (Yingline and McGill, 1999). Therefore, operators have risks in prevalence of the musculo-skeletal disorders due to shear force. The findings of this study suggest that it need to be determine the spinal load, especially lateral shear force in designing the manual vehicles in the future.

• 무역상무연구
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• 제78권
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• pp.119-143
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• 2018

This research aims to review every important academic research on risk management in FTA and to suggest a future area for further research. This research area seems to focus on conceptual study or fact finding rather than on theory development or empirical research on causal relationship or theory testing. The National Assembly Digital Library analyzed the results of 3,576 researches on thesis and journals fromthe results of the FTA. Research on FTA is analyzed in four major themes. First, there have been previous studies on business performance such as FTA export performance and economic effect. Second, analyzed the effects of FTA in product and service. The products are classified into agricultural, marine products, manufacturing, textiles and clothing, medicinal pharmaceuticals, cosmetics, and others. Services are classified into educational and cultural contents, service industry and financial industry. Third, research on the risk management of FTA Origin is broadly classified into the use of country of origin and the verification of origin, and the use of origin includes the study of rules of origin and systems of origin and management. Origin verification was divided into origin verification and origin risk management. Fourth, study on the conclusion area of the FTA, studies were conducted on areas such as Korea-US FTA, Korea-China FTA, Korea-EU FTA, Korea-Japan FTA, Korea-Chile FTA, and Korea-ASEAN FTA. Search results through the FTA, focused on analyzing the FTA area and concept research by research purpose. In addition, research methods are mainly focused on documentary survey, and research areas are concentrated on specific countries such as China and USA. This implies a necessity for a future development in that research area. Other areas for future research may include case research on actual failures in FTA, proactive risk management strategy, and integrated risk management for export companies. Risk management in FTA may help investment expansion, and that is why research on the issue matters.

• 한국식품조리과학회지
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• 제31권1호
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• pp.98-102
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• 2015

Allium hookeri, a member of the onion family, has long been mainly cultivated for food and medicinal use in Southeast Asian countries, owing to its various biological properties. However, no studies of the anti-oxidative effects of fermented A. hookeri root extracts have been conducted to date. Therefore, this study investigated the effect of different starter cultures on the antioxidant activities of hot water extract of A. hookeri root by using the following five strains: Lactobacillus acidophilus, Bifidobacterum longum, Enterococcus faecium, Streptococcus thermophilus, and Saccharomyces cerevisiae. DPPH and ABTS radical scavenging activity, total phenolic acid contents, and total antioxidant capacity were higher in the hot water extract of A. hookeri root fermented with starter cultures than those of A. hookeri root. Among hot water extract of A. hookeri root fermented with starter cultures, fementing with S. cerevisiae showed the highest antioxidant activities. The results of this study provide new evidence of the anti-oxidative properties of A. hookeri root with starter cultures, indicating that it may be highly valuable as a natural product owing to its high-quality functional components.

• Journal of the Korean Wood Science and Technology
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• 제28권3호
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• pp.9-13
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• 2000

본 연구는 해마다 100만 톤 이상이 생산되는 국내산 왕겨를 이용하여 왕겨보드를 제조함에 있어, 무처리 왕겨로 제조한 왕겨보드의 기계적 성질의 단점을 보완하기 위하여 왕겨를 전처리함으로써 그 물리 기계적 성질을 개선하기 위해 실시되었다. 연구결과를 요약하면, 무처리, 증자처리 및 가성소다로 알칼리처리한 왕겨보드보다 폭쇄처리한 왕겨보드가 휨강도 및 박리강도가 더 높았으며, 이때 적정 폭쇄처리 조건은 압력 20kgf/$cm^2$, 시간 1분과 압력 25kgf/$cm^2$, 1분이었다. 무처리 왕겨보드의 경우 휨강도, 박리강도 모두 KS를 만족시키지 못한 반면, 폭쇄처리 왕겨 보드의 경우 KS PB 18.0형의 기준을 모두 만족시켰으며, PB 대조구와 비교할 때 동등한 강도를 보였다. 기타 왕겨 전처리의 경우에 있어서도 가성소다처리보다는 증자처리가 왕겨보드의 강도를 향상시키는 것으로 나타났다.

• Journal of Biosystems Engineering
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• 제16권1호
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• pp.60-82
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• 1991

Drying process of red pepper is very important in terms of drying cost and quality of the end product. Recently, many studies on red pepper drying have been performed. Nevertheless, an optimum drying condition is not established yet. Drying characteristics of red pepper is much affected by drying factors such as variety and initial state of red pepper as well as by environmental drying factors such as temperature and relative humidity of drying air. Various varieties of red pepper are being cultivated and the initial state of red pepper at harvest is very ambiguous. For this reason, it is very costly and time-consuming to establish an optimum drying condition of red pepper by experiment. A general drying model to descirbe a drying process has not been developed due to diversity of drying characteristics of red pepper. This study was, therefore, performed to develop a general drying model describing a drying process of red pepper. The results from this study are summarized as follows. 1. A basic model was established to develop an appropriate mositure content model and temperature model describing a drying process of red pepper, and the basic model was validated with experimental data. 2. The bone dry weight of fruit and mositure content were accepted satisfactorily as parameter to define the arbitrary red pepper. 3. The equilibrium moisture content of red pepper was found out to be different according to the variety of red pepper, air temperature and relative humidity. Also, the EMC model was developed using the parameters of air temperature, relative humidity and bone dry weight of fruit. 4. A general drying model for red pepper was developed, parameters of which were expressed as the function of drying factors related with drying phenomena. The developed drying model was found out to describe well the drying process of red pepper.

• 한국환경복원기술학회지
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• 제11권3호
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• pp.39-49
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• 2008

A study was carried out on the physico-chemical properties of soil and content of heavy metals and benzo(a)pyrene that might have been introduced through by-product fertilizers or air pollution to growing turfgrass at natural turfgrass playgrounds in elementary schools located at the western coast and eastern mountain areas in Jeollabuk-do, Korea. The soil of turfgrass playgrounds is composed of loamy sand, and the CEC and organic matters were very low. Compared to agricultural land in Korea, the concentrations of nitrogen, phosphorus and potassium were very low, requiring control in terms of nutrients. The contents of total and fraction heavy metals in soil were found to be background level. The reason may lie in the fact that unpolluted sand soil or sand was used to construct the foundation for the natural grass playground in the first place. However, any change in oxidation-reduction conditions or acceleration of decomposition of organic compounds may release some heavy metals from the soil and be transformed into forms that may be easily absorbed by plants or grass. It is believed that sustained monitoring and environment impact assessments should be carried out. The contents of benzo(a)pyrene in soil showed an average 0.60ng/g with a range between 0.06 to 1.47ng/g. The detected contents were found as background level.