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        검색결과 379

        82.
        2016.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The feeding habits of juvenile Chaenogobius annularis were examined based on gut content analysis of 281 individuals, collected from May to June 2011 in the coastal water of Geoje, Korea. Copepods were the main source of food for C. annularis, which constituted 61.6% in IRI. Barnacle larvae was the second largest dietary component. Graphical analysis of the diet composition showed that C. annularis was a specialized predator characterized by strong individual feeding specialization. Both small and large size class of C. annularis mainly consumed harpacticoida and cirripedia cypris.
        4,000원
        83.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate the response characteristics and performance of a biofilter in the removal of ammonia, as a malodor compound. A trickle-bed type biofilter was applied for this study, and operated at the ammonia loading rate of 0.97-15.52 g/m3·h. The results of the experiment indicate that the critical loading rate of ammonia to the biofilter was 10.7 g/m3·h and the elimination capacity was 11.6 g/m3·h. The analysis of nitrogen mass balance in the reactor indicates that inlet nitrogen as gas phase was converted through the biofilter into NH4 + (41.5% by mass), NO2 - (43%), and NO3 - (15%) as the available form of nitrogen in the effluent liquid. Free ammonia concentration in the effluent liquid was estimated as being in the range from 0.14 to 2.93 mg/L (average 1.7 mg/L) during the experimental period.
        4,000원
        84.
        2016.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A commercial NiO (green nickel oxide, 86 wt% Ni) powder was reduced using a batch-type fluidized-bed reactor in a temperature range of 500 to 600 oC and in a residence time range of 5 to 90 min. The reduction rate increased with increases in temperature; however, agglomeration and sintering (sticking) of Ni particles noticeably took place at high temperatures above 600 oC. An increasing tendency toward sticking was also observed at long residence times. In order to reduce the oxygen content in the powder to a level below 1 % without any sticking problems, which can lead to defluidization, proper temperature and residence time for a stable fluidized-bed operation should be established. In this study, these values were found to be 550 oC and 60 min, respectively. Another important condition is the specific gas consumption rate, i.e. the volume amount (Nm3) of hydrogen gas used to reduce 1 ton of Green NiO ore. The optimum gas consumption rate was found to be 5,000 Nm3/ton-NiO for the complete reduction. The Avrami model was applied to this study; experimental data are most closely fitted with an exponent (m) of 0.6 ± 0.01 and with an overall rate constant (k) in the range of 0.35~0.45, depending on the temperature.
        4,000원
        85.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to develop the movable bed cultivating system for strawberry cultivation that enables to increase crop yield and save labor through high-density cultivation. In comparison with a conventional raised-bed system, the best feature of the system is a culture bed moving freely, left, right, up and down. This system consists of four devices; longitudinally- and laterally-moving device, nutrient solution supply device, and a control device. A comparative study showed that there was no significant difference on strawberry growth between a conventional raised bed and the movable bed cultivation systems. In addition, the change of growing environment to high-density cultivation did not influence strawberry growth, which proved the applicability of the movable bed cultivation system. Additional finding of this study showed that about 1.7 times more plants can be planted in movable beds. High-density cultivating using movable beds enables to plant more strawberry within the same cultivated area, which eventually contribute to reduce energy consumption per strawberry.
        4,000원
        86.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to compare the ichthyofauna between the eelgrass bed waters located in the open sea and the nearby sea free of eelgrass, and this study collected a total of 26 species. Comparing the fish collected on the eelgrass bed (St.2) of Geomun–do coast with the fish collected on the coastal waters (St.1) void of the nearby eelgrass bed, the fish collected from the eelgrass bed included 19 species, 413 individual with 16,110.6g in weight while the fish collected from the coastal waters void of the eelgrass bed included 19 species, 290 individuals with 12,961.5g in weight. Accordingly, it was found that the population size and biomass of the fish collected from the eelgrass bed were higher than the coastal waters void of the eelgrass. This study could identify that diversity, richness, evenness index except dominance were also much higher even in the result of cluster analysis.
        4,000원
        87.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out in order to evaluate the design suitability of gas scrubbers, which have been operated in Siheung and Ansan Smarthubs, as an odor removal device. Detailed design data of 31 gas scrubbers installed between 2005 to 2014 were investigated. All the scrubbers investigated were found to use a “packed bed” design, and 30 of them used pall rings as packing materials. In determining the bed diameter of scrubbers, many facilities used incorrect packing parameters, which resulted in inappropriate design values for the bed diameter. In determining of the height of packed bed, the height of transfer unit (HTU) was calculated incorrectly because of the misuse of both the constants of packing materials and Schmidt numbers. In addition, the values of number of transfer unit (NTU) were found to be underestimated due to the low removal efficiency goal. Therefore, the adapted values of packed bed height were quite different from the ones calculated in many facilities.
        4,000원
        88.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        전 세계적으로 범죄율 감소를 위한 방범기술에 대한 관심도가 높으며, 특히 국내의 경우에는 방범 App과 CCTV구축사업이 국가중점사업으로 전국적으로 추진되고 있다. 하지만 범죄 검거율 저조 등의 효과 미비, CCTV 관제요원의 모니터링 업무 과부하 등으로 인하여 지능형 방범기술의 필요성은 높아져 가고 있다. 하지만 기술검증의 문제로 인하여 실제 지자체에서는 지능형 방범기 술 활용이 어렵다. 또한 성공적 범죄예방을 위해서는 국내 다양한 법제도적 제약 극복, 시민들과의 피드백, 관계기관들과 협력 등의 기술검증 이외 사항들을 고려해야 한다. 따라서 시민들이 거주하는 실제 환경에서 기술을 테스트하고 효과를 검증하는 실증지 구의 구축이 중요한 역할을 할 수 있으며 차후 기술의 사업화/상품화에도 유리한 측면이 있다. 성공적 실증지구의 구축을 위해 그 첫 단계라고 할 수 있는 실증지구의 선정기준이 매우 중요하다. 따라서 본 연구에서는 기존의 R&D와 성격을 달리하는 “지능형 방범기술 R&D 사업”을 대상으로 실증지구의 선정 시 고려사항 및 기준들을 객관적으로 제시하여 차후 확대될 것으로 예상되는 실증지구 선정에 기여하는 것을 목표로 한다.
        4,200원
        89.
        2015.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The influencing factors to remove phosphate were evaluated by converter slag (CS). Experiments were performed by batch tests using different CS sizes and column test. Solutions were prepared at the different pH and concentrations. The maximum removal efficiency was obtained over 98% with the finest particle size, CSa within 2 hours in batch tests. The removal efficiency was increased in the order of decreasing size with same amount of CS for any pH of solutions. The adsorption data were well fitted to Freundlich isotherm. From the column experiment, the specific factors were revealed that the breakthrough removal capacity (BRC) xb/mcs, was decreased by increasing the influent concentration. The breakthrough time, tb was lasted shorter as increasing the influent concentration. The pH drop simultaneously led to lower BRC drop during the experimental hours. The relation between the breakthrough time and the BRC to influent concentration was shown in the logarithmic decrease. Results suggested that the large surface area of CS possessed a great potential for adsorptive phosphate removal. Consequently particle size and initial concentration played the major influencing factors in phosphate removal by converter slag.
        4,000원
        90.
        2015.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The present study prepared molybdenum trioxide (MoO3), the most important intermediate of molybdenum metal, by using a fluidized bed reactor for the thermal decomposition of ammonium molybdate (AM) in the presence of an air flow. During the process of fluidizing the sample inside the reactor, the reaction time and temperature were optimized with a close analysis of the X-ray diffraction (XRD) data and with thermogravimetric analysis (TGA). In particular, the temperature level, at which the AM decomposition is completed, is very important as a primary operating parameter. The analysis of the XRD and TGA data showed that the AM decomposition is almost completed at ~350 oC with a reaction time of 30 min. A shorter reaction time of 10 min. required a higher reaction temperature of ~500 oC with the same air flow rate to complete the AM decomposition. A sharp rise in the decomposition efficiency at a temperature ranging between 320 and 350 oC indicated a threshold for the AM decomposition. The operating conditions determined in this study can be used for future scale-ups of the process.
        4,000원
        91.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study spent mushroom substrate has ingredient raising rice bed soil. spent mushroom substrates are organiccontent is 60.72% were nitrogen - phosphoric acid - potassium is 1.39 - 0.89 - 0.81% of the chemical characteristics determine.Post-harvested mushroom substrates of the stabilization process, the temperature of the 20 days time progress in the pH of therise and fall of temperature down were germination index also 77, as identified, Spent mushroom substrate bed soil for raisingrice Ingredient to take advantage of the 20 days or more stabilization process needed to be investigated. Rice seed germinationcharacteristic is in the common bed soil for raising rice ingredients manufactured control group and the comparison in spentmushroom substrate is 10% or less of a mixed experimental population of the germination rate is 82% was more than averagedays to germination and germination energy, even a statistical significant difference is or control group than good level was ok.Growth initial also spent mushroom substrate is 10% or less of a mixed experimental population of shoot dry matter (top) andgrave less than control group higher as confirmed spent mushroom substrates are bed soil for raising rice ingredients are likely totake advantage of the high, as was the judge.
        4,000원
        92.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        양송이 수확후 배지로부터 lipase 생산균을 분리하여 16S rDNA 유전자 분석을 통해 동정한 결과, Burkholderia cepacia ATCC와 99.8% 상동성을 나타냈다. 분리균 B. cepacia 배양여액 중에 함유된 효소단백질을 70% 황산암모늄으로 침전시켜 crude lipase를 회수하였다. 고정화 효소를 제조하기 위하여 crude lipase(CL)과 Novozyme lipase(NL)을 cross-linking 법에 의해 Silane화된 Silicagel에 고정화 시킨 결과, immobilized CL(ICL)은 61%, immobilized NL(INL)은 72%의 잔존활성을 유지하였다. 중성지방 Canola oil을 알칼리(NaOH) 촉매와 효소(CL 및 ICL) 촉매를 이용하여 지방산(fatty acid)으로 분해한 후, methanolysis에 의한 에스터전이반응(trans-esterification)을 통해 지방산으로부터 전환된 바이오디젤(fatty acid methyl ester, FAME)의 종류와 수율을 비교 하였다. 생성된 총 FAME 함량은 NaOH 781mg L-1, free lipase 681mg L-1, 고정화 lipase 598mg L-1순으로 높았으며, 지방산 조성별 FAME 함량은 linoleic acid(C18:1)가 약 50%로 가장 높았으며, stearic acid(C18:0)가 22%정도의 높은 수준이었다. 또한 반응시간이 증가함에 따라 CL과 ICL 모두 불포화지방산 FAME의 조성비는 감소하고, 상대적으로 포화지방산 FAME의 조성비는 증가하는 경향을 보여 lipase 효소가 transesterification 활성과 interesterification 활성을 동시에 가지는 것으로 여겨진다. 고정화효소의 잔여활성은 반복회수가 증가함에 따라 서서히 감소하여 4회 반복 후, 초기 활성도에 비해 ICL은 34% 와 INL은 21%까지 감소하였다.
        4,000원
        93.
        2014.12 구독 인증기관 무료, 개인회원 유료
        New e-navigation strains require new technologies, new infrastructures and new organizational structures on bridge, on shore as well as in the cloud. Suitable engineering and safety/risk assessment methods facilitate these efforts. Understanding maritime transportation as a sociotechnical system allows the application of system-engineering methods. Formal, simulation based and in situ verification and validation of e-navigation technologies are important methods to obtain system safety and reliability. The modelling and simulation toolset HAGGIS provides methods for system specification and formal risk analysis. It provides a modelling framework for processes, fault trees and generic hazard specification and a physical world and maritime traffic simulation system. HAGGIS is accompanied by the physical test bed LABSKAUS which implements a physical test bed. The test bed provides reference ports and waterways in combination with an experimental Vessel Traffic Services (VTS) system and a mobile integrated bridge: This enables in situ experiments for technological evaluation, testing, ground research and demonstration. This paper describes an integrated seamless approach for developing new e-navigation technologies starting with simulation based assessment and ending in physical real world demonstrations.
        4,800원
        94.
        2014.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        To increase the mechanical property of zirconia, we have investigated the phase change and the resulting hardness of zirconia ceramics by hydroxyapatite (HA) powder bed sintering. It was observed using X-ray diffraction that the cubic zirconia phase, which has a higher hardness value than that of the tetragonal phase, was obtained at the surface of 3 mol% Y2O3 doped tetragonal zirconia polycrystal (3Y-TZP) ceramics during the sintering process; in our experimental conditions, the phase change at the surface increased as the sintering time increased. We believe that the observed crystalline phase change originated from the decomposition of HA and the diffusion of CaO, as follows. CaO, which was derived from the decomposition of HA at high temperature (1400˚C), diffused into the surface of 3Y-TZP and acted as a stabilizer. As a result, the Vickers hardness value of the treated specimens was higher than that of the non-treated specimen due to the formation of the cubic phase on the surface of 3Y-TZP.
        4,000원
        95.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study examined a feasibility of coagulation as post-treatment to remove sulfide and phosphorus for the effluent of anaerobic fluidized bed reactor (AFBR) treating domestic wastewater. Removal efficiencies of sulfide, phosphorus and COD by coagulation were not affected by pH in the range of 5.9 to 7.2. Alkalinity requirement could be estimated by the amount of Fe3+ to form Fe(OH)3(S) and to remove sulfide and phosphorus. At coagulant aid dosage of 2 mg/L, anionic polymer showed best results regarding size and settleability of flocs. Sulfide removal for the AFBR effluent at the Fe3+/S2- ratio of 0.64, close to the theoretical value of 0.67 found with a synthetic wastewater, was only 75.2%. One of the reasons for this low sulfide removal is that the AFBR effluent contains, phosphorus, hydroxide and bicarbonate which can react with Fe3+ competitively. Concentrations of sulfide and phosphorous reduced to below 0.1 and 0.5 mg/L, respectively, at the Fe3+/S2- ratio of 2.0. Average effluent COD of 80 mg/L, mostly soluble COD, was obtained at the dosage 50 mg Fe3+/L (Fe3+/S2- ratio of 2.0) with corresponding COD removal of 55%. For better removal of COD, soluble COD removal at the AFBR should be enhanced. Coagulation with Fe3+ removed sulfide, phosphorus and COD simultaneously in the AFBR effluent, and thus could be an alternative process for the conventional wastewater treatment processes where relatively high quality effluent is not required.
        4,300원
        96.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In our country, the number of coffee shops has steadily increased, reaching approximately 15,000 in 2013 from 1,254 in 2006. Adding to increase of coffee shops, customers' preference of roasted beans and extraction to ready-made coffee or instant coffee has lead to rapid expansion of roasted coffee market. In this study, the semi-rotating fluidized bed roaster prototype to reduce LPG consumption of the existing 60kg class large rotating fluidized bed roaster has been designed and retrofitted. In addition to the roaster prototype, processing system consist of bean automatic feeding equipment, debris sorting device, cooling device, cyclone collector, main control system etc. was developed. Also, the authors carrying out many measurements and tests such as LPG consumption, bean transfer time, debris sorting rate, cooling time and temperature, chaff collection rate for the various cases. As a result, the authors found that the semi-rotating fluidized bed roaster prototype can not only reduce LPG consumption, green bean transfer time, cooling time and temperature but also improve debris sorting rate, chaff collection rate of during coffee roasting
        4,000원
        97.
        2014.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        가시망둑(1.80~10.01 cm TL)의 성장과 생산량에 대한 연구를 동대만 잘피밭에서 2006년도에 실시하였다. 가시망둑 시료는 소형 빔트롤로 총 702개체를 채집하였다. 본 연구 결과, 가시망둑에 대한 전장(TL)의 성장식은 TL=0.0539 d0.9105, 전장과 체중의 관계식은 W=0.0079 TL3.1103 이었다. 가시망둑의 단위면적당 밀도, 생체량, 일일생산량, 연간생산량은 각각 0.06±0.062/m2, 0.10±0.144 g/m2, 0.0005±0.0006 g AFDW/m2/day, 0.1833 g AFDW/m2/year이었으며, P/B의 비율은 1.813이었다. 가시망둑 생산량은 생체량의 높았던 5월과 7월 9월에 가장 높았으며(0.0029, 0.0031, 0.0019 g AFDW/m2/day), 생체량이 낮았던 12월에 가장 낮았다(0.00004 g AFDW/m2/day). 가시망둑의 월별 생산량의 변화에서 양의 상관관계를 보인 것은 생체량과 수온이었다.
        4,000원
        98.
        2014.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Freezing of the pure water saturating a packed bed of spheres in a rectangular cavity is performed experimentally to investigate the effect of bead diameter on the heat transfer rate and temperature vs. time history for the pure water freezing experiments were compared with the freezing of the binary solution(HO-NaCl). Spherical soda-lime glass beads of 2.85mm and 6mm in average diameter constitute the porous medium. The system is cooled through its bottom surface, and the top is maintained at a temperature above the liquids. There was small effect on the temperature distribution in the system of the porosity difference.
        4,000원
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