• Geomechanics and Engineering
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• 제4권4호
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• pp.281-294
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• 2012

Filtration using granular media such as quarried sand, anthracite and granular activated carbon is a well-known technique used in both water and wastewater treatment. A relatively new pre-filtration method called pebble matrix filtration (PMF) technology has been proved effective in treating high turbidity water during heavy rain periods that occur in many parts of the world. Sand and pebbles are the principal filter media used in PMF laboratory and pilot field trials conducted in the UK, Papua New Guinea and Serbia. However during first full-scale trials at a water treatment plant in Sri Lanka in 2008, problems were encountered in sourcing the required uniform size and shape of pebbles due to cost, scarcity and Government regulations on pebble dredging. As an alternative to pebbles, hand-made clay pebbles (balls) were fired in a kiln and their performance evaluated for the sustainability of the PMF system. These clay balls within a filter bed are subjected to stresses due to self-weight and overburden, therefore, it is important that clay balls should be able to withstand these stresses in water saturated conditions. In this paper, experimentally determined physical properties including compression failure load (Uniaxial Compressive Strength) and tensile strength at failure (theoretical) of hand-made clay balls are described. Hand-made clay balls fired between the kiln temperatures of $875^{\circ}C$ to $960^{\circ}C$ gave failure loads of between 3.0 kN and 7.1 kN. In another test when clay balls were fired to $1250^{\circ}C$ the failure load was 35.0 kN compared to natural Scottish cobbles with an average failure load of 29.5 kN. The uniaxial compressive strength of clay balls obtained by experiment has been presented in terms of the tensile yield stress of clay balls. Based on the effective stress principle in soil mechanics, a method for the estimation of maximum theoretical load on clay balls used as filter media is proposed and compared with experimental failure loads.

• Journal of Microbiology and Biotechnology
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• 제14권5호
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• pp.906-913
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• 2004

A culture-independent molecular phylogenetic survey was carried out on the bacterial community in cold-seep sediment at Edison Seamount, south of Lihir Island, Papua New Guinea. Small-subunit rRNA genes were amplified directly from the sediment DNA by PCR and cloned. The majority of the cloned 16S rRNA gene sequences were most closely related to as-yet-uncultivated microorganisms found in deep-sea sediments, and were primarily affiliated with one of four groups: the $\gamma$-, $\delta$-, and $\epsilon$-subdivisions of Proteobacteria, and Cytophaga-Flavobacterium-Bacteroides. We did not recover any sequences related to cyanobacteria, prochlorophytes, and $\alpha$-Proteobacteria, which are known to occur in great abundance within the surface mixed layer of the Atlantic and Pacific Oceans. The majority of the cloned $\gamma$-and $\epsilon$-Proteobacterial sequences were closely related to chemoautotrophic sulfur-oxidizing symbionts of marine benthic fauna, and the $\delta$-Proteobacterial sequences to sulfate- and sulfur-reducing bacteria, indicating that they might play an important role in chemoautotrophic primary production and the sulfur cycle in the cold-seep area. There results demonstrate the high diversity of the bacterial community in the cold-seep sediment, and substantially expand knowledge of the extent of bacterial diversity in this formidable and unique habitat.

• Journal of Microbiology
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• 제43권2호
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• pp.172-178
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• 2005

To determine the prevalence and genotypes of $\beta$-lactamases among clones of a metagenomic library from the cold-seep sediments of Edison seamount (10,000 years old), we performed pulse-field gel electrophoresis, antibiotic susceptibility testing, pI determination, and DNA sequencing analysis. Among the 8,823 clones of the library, thirty clones produced $\beta$-lactamases and had high levels of genetic diversity. Consistent with minimum inhibitory concentration patterns, we found that five ($167\%$) of thirty clones produced an extended-spectrum $\beta$-lactamase. 837- and 259-bp fragments specific to bla$_{TEM}$ genes were amplified, as determined by banding patterns of PCR amplification with designed primers. TEM­1 was the most prevalent $\beta$-lactamase and conferred resistance to ampicillin, piperacillin, and cephalothin. TEM-116 had a spectrum that was extended to ceftazidime, cefotaxime, and aztreonam. The resistance levels conferred by the pre-antibiotic era alleles of TEM-type $\beta$-lactamases were essentially the same as the resistance levels conferred by the TEM-type alleles which had been isolated from clinically resistant strains of bacteria of the antibiotic era. Our first report on TEM-type $\beta$-lactamases of the pre-antibiotic era indicates that TEM-type $\beta$-lactamases paint a picture in which most of the diversity of the enzymes may not be the result of recent evolution, but that of ancient evolution.

• 수산해양기술연구
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• 제41권4호
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• pp.263-270
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• 2005

This paper summarizes characteristics of the Korean tuna purse seine fishery in the Western and Central Pacific Ocean (WCPO). Major fishing area for the Korean tuna purse seine fleet consisted of the waters of Micronesia, Papua New Guinea and Solomon Islands and adjacent high seas between $130^{\circ}E-180^{\circ}$ The center of the Korean tuna fishing ground was in the vicinity of $180^{\circ}$ during the El - $Ni{\tilde{n}}$o event but was formed in $150^{\circ}-160^{\circ}$E during the La - $Ni{\tilde{n}}o$ event. As compared with other major purse seine fleets in WCPO, the Korean fleet set more on unassociated schools of tuna, while Japan, USA and Chinese - Taipei fleets accounted for more than 50% of sets on log - associated schools. In general, CPUES for log - associated schools were higher than those for unassociated schools and catch composition showed that yellowfin ratio was higher in unassociated shools than log - associated schools. Length frequency represented higher percentage of mid - sized yellowfin than Japanese and USA fleets. Daily set numbers and CPUE were high before 7 am and remained almost constant from 7 am to 3 pm but decreased rapidly after 3 pm and 5 pm, respectively. Catch composition per set indicated that pure skipjack school was caught most frequently, followed by mixed school and pure yellowfin school as the least, but CPUE was highest for the mixed school.

• 수산해양기술연구
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• 제52권4호
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• pp.356-363
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• 2016

To suggest more efficient fishing operation, it was analyzed using five years (2011~2015) catch data of six Korean-flagged tuna purse seiners (with 1000 mt of haul capacity) operating in the western and central Pacific Ocean. In terms of annual total catch, it presented a two-year cycle of variation on catch, showing that catches of 2012, 2014 and 2015 were high, whereas those of 2011 and 2013 were low. The proportions on fishing effort of associated set were around 21.9~30.8% having 21.5~45.0% of total catch. In this study, there was no significant difference between catches of unassociated set and associated set. When considered having good fishing conditions, fishing activities were concentrated in the areas of Papua New Guinea (PNG) and Kiribati, while it showed that fishing ground spreaded out to the areas of not only PNG and Kiribati but also Federated States of Micronesia (FSM), Tuvalu and Solomon islands. The average number of fishing days was 271 with a range of 246~285. As restriction on fishing operation such as reduction of fishing days and higher fishing fee are expected to strengthen, the result of this study will be helpful to select more efficient fishing methods for purse seine fishery based on fishing conditions.

• Tuberculosis and Respiratory Diseases
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• 제45권4호
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• pp.888-895
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• 1998

Malaria is one of the most common infectious diseases in the world. Plasmodium falciparum, accounting for nearly all malaria mortality, kills an estimated 1 to 2 million persons yearly and has several features that make it deadlist of malarias. While cerebral malaria is the most common presentation of severe disease, acute lung injury associated with malaria is uncommon but serious and fatal complication. We report two cases of severe malaria with ARDS and multi-organ failure. All two patients traveled to foreign countries, Kenya, Papua New Guinea where choroquine-resistant malaria is distributed. The first case, which developed cerebral malaria, hypoglycemia, multi-organ failure, and ARDS, treated with quinine and mechanical ventilator, but expired due to oxygenation failure. Autopsy showed acute necrotizing infiltration, diffuse eosinophilic fibrinoid deposits along the alveolar space, and alveolar macrophage with malaria pigment The second case also developed multi-organ failure, followed by ARDS, and was treated with quinine, exchange transfusion, plasmapheresis, and mechanical ventilator. He recovered with residual restrictive lung change after treatment.

• Journal of the Korean Wood Science and Technology
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• 제52권1호
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• pp.70-86
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• 2024

Termites are a serious threat to wood-based products in Indonesia. This study investigated the termite resistant property of glulam made from polystyrene-modified wood. Three tropical fast-growing wood species, namely mangium (Acacia mangium), manii (Maesopsis eminii), and rubberwood (Hevea brasiliensis), were prepared for flat-sawn laminae. After getting air-dried condition, the laminae were impregnated with polystyrene using potassium peroxydisulphate as a catalyst followed by polymerization at 80℃. Polystyrene-impregnated and control glued-laminated lumbers (glulams) were manufactured, and solid wood was provided. Three wood species and three wood products with six replicates were exposed in a field in Bogor, Indonesia, for four months, and before the tests, their density and moisture content were measured. At the end of the field tests, the weight loss and protection levels of each test sample were determined. A completely randomized factorial design was used for data analysis. The weight percentage gains for mangium, manii, and rubberwood were 22.30%, 18.22%, and 10.44%, respectively. The results showed that manii belonged to low-density wood, whereas the other two woods were medium-density wood, and the moisture content was the ambient moisture content, typical of the Bogor area. Regarding weight loss and protection level, mangium was the most durable against subterranean termite attacks, followed by rubberwood and manii. Among the wood products, the polystyrene-impregnated glulam presented the highest durability, followed by the control glulam and solid wood. Therefore, mangium and rubberwood polystyrene-impregnated glulams are recommended for future product development.

• 현장농수산연구지
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• 제13권1호
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• pp.173-183
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• 2011

1. Gabensis 마을은 3천여명의 인구를 가진 Morobe 지역의 Wampar 지방 정부 수준 영역에서 가장 큰 마을 중 하나이다. 2. 주식은 바나나를 비롯하여 마, 카사바, 토란과 고구마가 있다. 그 외에도 마을 사람들이 그들의 생계를 보완하기 위해 야채, 코코아 가루, 코코넛, 목재, 닭고기, 생선, 돼지고기 생산 및 판매에 종사하고 있다. 3. Gabensis 마을 호수 Wanam호수의 자연적인 매력은 농촌관광 사업으로 개발 가능한 잠재력이 있다. 특히, 에코빌리지를 중심으로 지역 사회를 위한 거대한 경관농업의 가치 창조가 필요하다. 정부 서비스 제공과 개발, 교육 및 건강 문제의 일환으로 중요한 지역이다. 4. 넓은 경지면적을 지니고 있지만 경지 정리 및 수리시설 미비로 농업용수가 부족하고 농사에서도 기술수준이 낮아 농업 생산성이 떨어진다. 생산 기술만 제공되면 마가 향후 마을의 중심 작목으로 주민들의 중요한 소득원이 될 것을 기대하고 있다.

• 현장농수산연구지
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• 제3권1호
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• pp.48-69
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• 2001

1997년 부터 한국농업전문학교에서 수집하여 재배되고 있는 마 (Dioscorea alata L.) 계통 중 품질이 우수하고 이용 가치가 기대되는 33개 계통에 대한 특성을 조사하였으며, 형태적 차이를 보이는 19개 계통에 대한 RAPD분석을 실시하였다. 1. 주당 괴경의 전체 무게는 최대 2,147g (No.36), 최소 90g (No.20)으로 평균 610g이었다. 주당 평균 괴경수는 2.8개였으며 최대 4.7개, 최소 1.3개였다. 괴경중은 평균 363g이었으며 최대 1200g, 최소 70g이었다. 2. 괴경의 육질은 백색, 담황색 및 적자색 3가지 패턴을 보였으며, 잎은 녹색, 진녹색 및 담녹색으로 분류되었다. 3. RAPD 분석에 사용된 총 113개 primers 중 12개 primer 만이 모든 분류군에서 증폭되었다. 이를 통하여 93개의 밴드를 얻었으며 69개 밴드는(71.0%) polymorphic 하게 나타났다. 4. 유집분석 결과 19개 계통은 유사도 지수 값 0.66~0.90의 범위로 나타났으며, 크게 2개의 그룹, 즉 인도네시아와 가고시마에서 도입된 8개의 계통이 포함된 그룹과, 유사도지수 0.70~0.90의 범위를 갖는 Nauru, Palau Is., Okinawa와 Papua New Guinea에서 도입된 11 계통이 포함된 그룹으로 대별되었다.