The representative emission index and indicator are the EEDI (Energy Efficiency Design Index) for the new ships and EEOI (Energy Efficiency Operational Indicator) during the voyage. In this paper, derating of diesel main engine are introduced for the purpose of improving EEDI. The results showed good agreement explaining the characteristics properly.

생물학적 위험등급 3등급 BL3용 공조기의 급배기는 밀폐 연구시설 사이의 교차오염을 막기 위하여 관계 규정에 의거 전외기 방식을 택하고 있다. 이와 같은 전외기 방식의 공조기는 에너지 소비가 많으며 게다가 BL3의 경우 하루 24시간 운전으로 인하여 에너지 소비가 매우 많으며 또한 연구시설의 대형화로 인하여 에너지 소비는 더욱 증가하게 될 것이다. BL3용 공조기에서의 에너지 절약에 관한 연구로는 국외의 경우 전외기 방식에서 급기와 배기덕트 사이에 부동액 등을 사용한 핀-튜브 열교환기를 사용하여 배기로부터 열회수를 통한 에너지 절약에 관한 연구를, 국내의 경우 생물학적 안전성을 기반으로 하는 재순환에 의한 에너지 절약에 관한 연구를 시도하고 있다. 본 연구에서는 기존의 BL3용 공조기에서 주로 사용하는 핀-튜브 열교환기와 마이크로 채널 열교환기에 대한 특성을 비교, 연구하였고 마이크로 채널 제작을 위한 열교환기 설계 프로그램을 개발하였다.

이 연구의 목적은 전국 고추농가를 대상으로 지역별 효율성 및 지역내 효율성 분포를 분석하여 고추농가 경쟁력 향상을 위한 정책적 시사점을 도출하는 기초자료로 활용하는데 있다. 분석결과 전국 고추농가의 평균 기술효율성, 순수기술효율성, 규모효율성 모두 비효율적인 것으로 나타났다. 기술효율성(CRS 가정)은 제주, 전남, 강원, 경북 순으로 상대적으로 높게 나타났으며, 순수기술효율성(VRS 가정)도 제주, 전남, 강원, 경북 순으로, 규모효율성은 강원, 전남, 경북, 충남 순으로 상대적으로 높게 나타났다.

A compressor in the refrigerator uses about 80% of the total consumption power required for refrigerating cycle. In this study, we consider the auxiliary piston equipped with a valve that can be controlled to open and close in order to dramatically increase the efficiency of a linear compressor. Turbocharger using the auxiliary piston was to improve the cooling capacity and efficiency of the compressor. The numerical results show that the cooling capacity was considerably improved by approximately 40.6% compared to that of the baseline model. In addition, COP increased about 7.6% indicating that the turbocharger was very efficient

Recently, Korea’s municipal wastewater treatment plants generated amount of wastewater sludge per day. However, ocean dumping of sewage sludge has been prohibited since 2012 by the London dumping convention and protocol and thus removal or treatment of wastewater sludge from field sites is an important issue on the ground site. The hydrothermal carbonization is one of attractive thermo-chemical method to upgrade sewage sludge to produce solid fuel with benefit method from the use of no chemical catalytic. Hydrothermal carbonization improved that the upgrading fuel properties and increased materials and energy recovery ,which is conducted at temperatures ranging from 200 to 350°C with a reaction time of 30 min. Hydrothermal carbonization increased the heating value though the increase of the carbon and fixed carbon content of solid fuel due to dehydration and decarboxylation reaction. Therefore, after the hydrothermal carbonization, the H/C and O/C ratios decreased because of the chemical conversion. Energy retention efficiency suggest that the optimum temperature of hydrothermal carbonization to produce more energy-rich solid fuel is approximately 200°C.

Recently, the production of taste and odor (T&O) compounds is a common problem in water industry. Geosmin is one of the T&O components in drinking water. However, geosmin is hardly eliminated through the conventional water treatment systems. Among various advanced processes capable of removing geosmin, adsorption process using granular activated carbon (GAC) is the most commonly used process. As time passes, however GAC process changes into biological activated carbon (BAC) process. There is little information on the BAC process in the literature. In this study, we isolated and identified microorganisms existing within various BAC processes. The microbial concentrations of BAC processes examined were 3.5×105 colony forming units (CFU/g), 2.2×106 CFU/g and 7.0×105 CFU/g in the Seongnam plant, Goyang plant and Goryeong pilot plant, respectively. The dominant bacterial species were found to be Bradyrhizobium japonicum, Novosphingobium rosa and Afipia broomeae in each plants. Removal efficiencies of 3 μg/L geosmin by the dominant species were 36.1%, 36.5% and 34.3% in mineral salts medium(MSM) where geosmin was a sole carbon source.

In this study, flat-type photocatalytic reaction system is applied to reduce toxic hexavalent chromium (Cr(VI)) to trivalent chromium (Cr(III)) in aqueous solution under UV irradiation. To overcome the limitation of conventional photocatalysis, a novel approach toward photocatalytic system for reduction of hexavalent chromium including nanotubular TiO2 (NTT) on two kinds of titanium substrates (foil and mesh) were established. In addition, modified Ti substrates were prepared by bending treatment to increase reaction efficiency of Cr(VI) in the flat-type photocatalytic reactor. For the fabrication of NTT on Ti substrates, Ti foil and mesh was anodized with mixed electrolytes (NH4F-H2O-C2H6O2) and then annealed in ambient oxygen. The prepared NTT arrays were uniformly grown on two Ti substrates and surface property measurements were performed through SEM and XRD. Hydraulic retention time(HRT) and substrate type were significantly affected the Cr(VI) reduction. Hence, the photocatalytic Cr(VI) reduction was observed to be highest up to 95% at bended(modified) Ti mesh and lowest HRT. Especially, Ti mesh was more effective as NTT substrate in this research.

해상교통안전진단제도가 도입(2009.11)된 후 운영 중 나타난 제도상·운영 측면에서의 개선사항을 반영하고, 제도의 효율성 제고 및 종합 관리를 위해 해상교통안전진단시행지침 전부개정(2012.3)을 통해 선박안전기술공단내 해사안전연구센터가 전문기관으로 지정되었다. 하지만, 개정된 관련 해사안전법령에는 안전진단서 사전검토, 진단대상사업에 대한 검토 의견 제시 등 유사 국내 평가제도에서의 전문기관과 비교하면 역할과 업무가 명확하지 제시되지 않았다. 이에 본 연구에서는 먼저 SWOT분석을 통해 전문기관 발전을 위한 추진전략을 수립하고, 처분기관, 사업자, 안전진단대행업자 등 관련 전문가 의견수렴 및 국내 유사 평가제도의 전문기관의 역할 및 운영현황을 비교분석하였다. 이를 통해 진단제도가 효율적으로 운영되고, 진단사업에 대한 환경변화에 능동적으로 대응 할 수 있도록 스크린·스코핑, 컨설턴트 시스템 도입을 위한 전문기관의 조직 구성과 운영체제 개선과 진단관련 주체들의 책임과 역할을 명확화하기 위해 해사안전법 개정 등 전문기관의 발전과 해양개발사업에 대한 통합관리를 위한 제도상·운영상의 개선사항 도출하여 제시하였다.

해상수색구조 책임기관인 해양경비안전본부는 해양사고에 대하여 적절히 대응한 것으로 평가되어 왔으나, 최근 발생한 세월호사고 발생 직후 초기단계의 신속 효율적인 대응에 실패함으로 인해 비판을 받게되었다. 이와 관련하여 저자는 향후 발생할 수 있는 해양사고시 인명손실을 최소화하기 위한 방안을 모색하기 위해 우리나라 해역에서 발생하는 해양사고의 특징을 분석하고, 수색구조조정과 인적자원을 중심으로 국가수색구조체계를 검토·분석하였다. 그 결과, 해양경비안전본부는 특히 연안역 해양사고에 신속하게 대응하기 위하여 고속구명정 및 구조헬기를 확충하여야 한다. 그리고 현행 조정체계의 운용상 문제점을 개선하기 위해 IMO 지침에 맞춰 구조조정 본부설치를 재조정하여야 하며, 수색구조요원의 전문성 제고를 위한 의무적 교육 및 자격 제도의 도입이 필요하다.

본 연구에서는 선박용 해수펌프에 회전수를 제어할 수 있는 인버터를 설치하여 효율적인 유량제어를 통한 소비전력 절감효과를 확인하고 해양생성물 부착방지시스템(MGPS)이 미설치된 곳에서 해수펌프의 유량제어가 시스템에 미치는 영향에 관하여 연구하였다. 실험은 항해중이나 정박중 항시 운전되고 있는 목포해양대학교의 실습선의 보조해수펌프와 냉동기 해수펌프를 이용하였으며, 정박과 국제항해로 구분하여 실험하였다. 연구 결과 해수온도가 18℃ 이하인 경우 펌프회전수는 58.3 % 감소시켜 운전이 가능하였으며 50 %의 소비전력 절감효과가 있었다. 해수온도가 34℃ 까지 상승하여도 펌프의 회전수는 91.6 %로 운전이 가능하였으며 20 %의 소비전력 절감효과가 있었다. 또한 해양생성물 부착방지시스템이 설치되지 않은 곳에서는 펌프의 회전수를 낮추어 유속이 저하하면 해양생성물의 부착을 가증시키는 결과를 알게 되었다.

본 연구는 가축분뇨 혐기성소화에서 발생된 바이오가스 이용 활성화를 위하여 효율적인 가스성상별 분리 및 정제 방법을 모색코자 수행하였다. 바이오가스의 분리 및 정제를 위하여 폴리술폰 고분자 소재를 상분리법을 이용하여 중공사막을 제조하였고, 중공사막이 충진된 맴브레인 모듈을 제작하여 바이오 가스 분리 및 정제를 실시하였다. 이러한 특징을 가진 중공사막을 사용하여 멤브레인 모듈을 제작하였으며, 제작된 멤브레인 모듈을 사용하여 혐기성소화조에서 발생하는 바이오가스를 분리 및 정제하였다. 바이오가스의 분리 및 정제를 위해서 멤브레인 모듈에 공급한 바이오가스는 실록산 0.1 ppm 이하, H2S 3 ppm 이하, Dewpoint –20℃ 이하로 제어하여 공급하였다. 멤브레인 모듈의 운전압력은 4∼7 ㎏f/㎠, 온도의 범위는 15∼45℃이였다. 가축분뇨에서 발생하는 바이오가스를 분리 및 정제한 결과, CH4 94.2%, CO2 92.0%로 분리 및 정제되었으며, 회수율은 CH4 102.1%, CO2 83.5%가 회수되었다. 따라서 본 연구에서 제작한 멤브레인 모듈을 사용한 바이오가스의 분리 및 정제 실험을 통해서 분리 전 바이오 가스의 성분(CH4 68%, CO2 28%, O2 0.6%, H2S 1 ppm 이하, Balance 2.7%)에 대해서 CH4 94.2%, CO2 92.0%의 고농도 분리 및 정제가 가능한 것을 알 수 있었다.

PURPOSES : The purpose of this study is to assess removal efficiency of non-point pollutants and applicability for non-point pollutant reduction facilities by conducting the demonstration project operation. METHODS : In order to analyze removal efficiency of non-point pollutants for facilities such as a grassed swale, a small constructed wetland, a free water surface wetland, a horizontal sub-surface flow wetland, and a sand filtration, the field data including specifications of facilities, rainfall, inflow and runoff rainfall effluent etc. was acquired after occurring rainfall events, and the acquired data was analyzed for removal efficiency rate to assess road non-point pollutants facilities using event mean concentration (EMC) and summation of load (SOL) methods. RESULTS: The results of analyzing rainfall effluent, non-point pollutant sources showed that total suspended solid (TSS), chemical oxygen demand (COD), biochemical oxygen demand (BOD), total nitrogen (TN), total phosphorus (TP), chrome (Cr), zinc (Zn), and lead (Pb) can be removed through non-point pollutant reduction facilities by 60.3% ~ 100%. Especially removal efficiency of TSS, COD and BOD is relatively higher than removal efficiency of other non-point pollutant sources in all kind of non-point pollutant facilities. CONCLUSIONS : Based on the result of this study, even though natural type of non-point pollutant reduction facilities for roads occupy small areas comparing with drainage basin areas, most of non-point pollutant sources would be removed through the facilities.

To synthesize a high-performance photocatalyst, N doped TiO2 nanotubes deposited with Ag nanoparticles were synthesized, and surface characteristics, electrochemical behaviors, and photocatalytic activity were investigated. The TiO2 nanotubular photocatalyst was fabricated by anodization; the Ag nanoparticles on the TiO2 nanotubes were synthesized by a reduction reaction in AgNO3 solution under UV irradiation. The XPS results of the N doped TiO2 nanotubes showed that the incorporated nitrogen ions were located in interstitial sites of the TiO2 crystal structure. The N doped titania nanotubes exhibited a high dye degradation rate, which is effectively attributable to the increase of visible light absorption due to interstitial nitrogen ions in the crystalline TiO2 structure. Moreover, the precipitated Ag particles on the titania nanotubes led to a decrease in the rate of electron-hole recombination; the photocurrent of this electrode was higher than that of the pure titania electrode. From electrochemical and dye degradation results, the photocurrent and photocatalytic efficiency were found to have been significantly affected by N doping and the deposition of Ag particles.

As sewer flooding frequents due to localized and concentrated stormwater and increased non-permeable surface area after urbanization, building cities with sound water recycle and accordingly efficient management of rainwater is demanded. To do this, the existing sewage (including rainwater) fee imposition system should be philosophically evaluated. This study presents problematic issues of the existing domestic sewage fee imposition system considering the principle of sharing costs on the service of sewage and rainwater collection and treatment. Four methods to improve the existing sewage fee imposition system are suggested: 1) imposing stormwater fee according to Polluter Pays Principle, 2) clarification of the share of public sector, 3) reducing or exempting the sewerage fee for inhabitants reducing urban runoff by constructing their own rainwater management facilities, 4) imposing charge for discharging rainwater to sewers due to new development action. Short, mid, or long term planning for rainwater management is recommended considering the situation of each municipality.

PURPOSES: In areas of high traffic volume, such as expressway across large cities, the amount of nitrogen oxides (NOx) emitted into the atmosphere as air pollution can be significant since NOx gases are the major cause of smog and acid rain. Recently, the importance of NOx removal has arisen in the world. Titanium dioxide (TiO2), that is one of photocatalytic reaction material, is very efficient for removing NOx. The NOx removing mechanism of TiO2 is the reaction of solar photocatalysis. Therefore, TiO2 in road structure concrete need to be contacted with ultraviolet rays (UV) to be activated. In general, TiO2 concretes are produced by replacement of TiO2 as a part of concrete binder. However, considerable portion of TiO2 in concrete cannot contact with the pollutant in the air and UV. Therefore, TiO2 penetration method using the surface penetration agents is attempted as an alternative in order to locate TiO2 to the surface of concrete structure. METHODS: This study aimed to evaluate the NOx removal efficiency of photocatalytic concrete due to various TiO2 application method such as mix with TiO2, surface spray(TiO2 penetration method) on hardened concrete and fresh concrete using surface penetration agents. The NOx removal efficiency of TiO2 concrete was confirmed by NOx Analyzing System based on the specification of ISO 22197-1. RESULTS: The NOx removal efficiency of mix with TiO2 increased from 11 to 25% with increasing of replacement ratio from 3 to 7%. In case of surface spray on hardened concrete, the NOx removal efficiency was about 50% due to application amount of TiO2 with surface penetration agents as 300, 500 and 700g/m2. The NOx removal efficiency of surface spray on fresh concrete due to all experimental conditions, on the other hand, which was very low within 10%. CONCLUSIONS: It was known that the TiO2 penetration method as surface spray on hardened concrete was a good alternative in order to remove the NOx gases for concrete road structures.

식물검역에서 선충검사는 일반적인 농업분야의 선충연구와 몇가지 다른 특징 을 가진다. 선충분리검사방법은 베르만깔데기법을 기본으로 필요한 목적에 맞게 적절하게 변형시켜 사용하였는데, 식물검역도 목적에 맞게 검사법을 개발하여 현 장에 적용하였다. 현재 우리나라에서 적용하고 있는 검사법은 침지변형베르만깔 데기체법(직접검경 - 침지 - 체법 - 변형베르만깔데기법)이다. 이 검사법에 소요되 는 시간은 품목에 따라 다르지만 침지 12-24시간, 변형베르만깔데기법은 8-12시간 이면 충분하다. 하지만, 이 검사법은 분리효율은 매우 높지만, 사람에 의한 작업에 의존하므로 2박 3일의 시간이 필요하다. 따라서 이에 대하여 시간과 인력을 절약할 수 있도록 이를 자동화 기계화하여야 한다. 또한 검사결과 검출되는 선충은 매우 다 양한 식물기생선충이 검출되는데, 현재 규제수준은 국내 미분포 식물기생선충은 모두 규제하고, 국내 분포 선충은 공적방제 대상을 제외한 모든 선충을 비검역으로 하는 시스템이다. 이를 침입 정착시 선충에 의한 피해수준과 종 동정 난이도 등을 함께 고려하여 식물에 큰 피해를 주는 몇몇 속(genus)과 종(species)을 규제하는 것 이 필요하다. 이것이 식물검역은 무역에 장애가 되지 않아야 한다는 WTO 정신에 적합할 것이다.

During the fierce competition among the companies, improvement of logistics center managing efficiency is importantly recognized. Among them, studies on improvement of picking work process on about 55% of logistics center managing costs are continuously conducted. And, most of studies focus on analysis on strengths and weaknesses of picking method performable on the stage of logistics center design, etc, so the purposes of this research are to define load location rule by product releasing frequency in logistics managing environment based on conveyer and suggest expected effects by simulation analyzing method to improve picking managing efficiency.

Sexed semen is commonly used for the production of calves of the desired gender. Gender selection is important in animal production industries. For example, female cattle are required for the dairy industry while males are preferred in the beef cattle industry. The present study was to assess the in vivo embryo production efficiency using the semen separated according to sex during superovulation in Hanwoo. Seventy Hanwoo donor cows were flushed on day 7 of estrus cycle with same FSH and artificial insemination by the same technicians. Embryos were recovered on 7 days after the third insemination by flushing the uterus with embryo collection medium. KPN semen straws used artificial insemination contained 20 million sperm (total number 60 million per donor). Sex-sorted semen straws contained 4 million sperm (total number 12 million per donor). The results obtained were as follows: No differences were observed in the efficiency of superovulation rates on KPN semen 87%, and sexed semen 100%, respectively. The mean numbers of total embryos are each 12.58±8.31 and 13.25±7.86. The mean numbers of transferable embryos, sexed semen were significantly lower than KPN semen (3.75±1.98 vs. 8.23±6.07, P＜0.05). The rates of unfertilized embryos from superovulation using sexed semen were significantly higher than KPN semen (50% vs. 15%, P＜0.05). The rate of degenerated 2-cell embryos from sexed and KPN semen was 60.87% and 11.11%, respectively (p＜0.05). In conclusion, these results indicate that superovulation using sexed semen was useful, but efficient embryo production was important to reducing the damage caused by the Flowcytometer-based sperm sorting procedure.