Thin-film nanocomposite (TFN) reverse osmosis (RO) membranes have drawn keen attention to overcome the limitations in polymeric desalination membranes. However, preparation of TFN-RO membranes using conventional protocol involves problems such as a waste of expensive nanomaterials and inaccurate control of loading amount. In this work, we suggest a new protocol of TFN-RO membranes through pre-adsorption of carbon nanotubes (CNTs) on the support layer using spray coating. SEM images of spray coated supports showed well-dispersed adsorption of CNTs compared with those using conventional method. RO performances of TFN membranes using spray coating were comparable to conventionally prepared membranes. Thus, this new protocol is useful to prepare TFN membranes in terms of cost-efficiency.

Ionic liquids (ILs) are potential drawing agents in forward osmosis (FO) due to their high ionicity, low vapor pressure and high solubility. A series of ILs were investigated as draw solutes for FO application and were compared with NaCl. Water (Jv )and reverse (Js) fluxes were evaluated using commercially available HTI-CTA membrane via FO and PRO modes. FO runs were conducted using 0.3M draw solution and DI water as feed. Results reveal that ILs like BMIM acetate, BMIM bromide and N4444 acetate were able to generate high Jv but with negligible Js. This demonstrates the potential of certain ILs as FO drawing agents. This research was supported by NRF through the Ministry of Science, ICT & Future Planning (No.2016R1A2B1009221) and through Basic Science Research Program of Ministry of Education(2009-0093816).

As an alternative to conventional explosive methods for demolition of concrete structures and rocks, the use of non-explosive demolition agents can be considered to reduce noise, vibration, and dust emissions during the demolition process. In this study, we conduct finite element analysis for crack initiation and propagation caused by the expansion of non-explosive demolition agents in square concrete structures. The predicted crack patterns are compared with the experimental results in the literature. The minimum values of the required expansion pressure of non-explosive demolition agents are also estimated, which depend upon the arrangement of non-explosive demolition agents and empty holes. Furthermore, we investigate the effect of empty holes on the fragmentation of concrete structures, and discuss the effective arrangement of non-explosive demolition agents and empty holes for fragmentation improvement.

All structures can not be perfect due to geometric or material initial imperfections. Initial imperfections are an important factor in determining the buckling mode and are known to be important factors in evaluating the actual buckling strength. The DNV-RP-C202 design standard limits the longitudinal stiffener spacing. However, the criteria for the stiffener spacing presented in DNV-RP-C202 is a guideline derived from the curved panel theory of perfect cross-sectional shape without initial imperfections. In this study, considering geometric initial imperfections, the transition point of stiffener spacing where longitudinal stiffeners affect the buckling strength of reinforced steel wind turbine tower is analyzed using finite element analysis program. The results of finite element analysis compared with theoretical results based on the perfect shape. As a result, a more reasonable stiffener spacing considering the initial imperfections was suggested.

To replace methyl bromide (MeBr) due to its ozone depletion properties and the life-threatening to related worker as well as fumigators, ethyl formate (EF) fumigation on exported and imported fruits and vegetables has been developed by QIA in Korea since 2005. The benefits of using ethyl formate (EF) fumigant is considered as the safest practice among the commercially available chemical alternatives. The issues was that the cylinderized EF with carbon doxide (CO2) is not enough to extend their applications in terms of fumigation cost. We have developed the cost-effective liquid EF applications with nitrogen gas and demonstrated in quarantine trials (10m3) on imported bananas. We showed the new 35 gm-3 of EF applications with inert gas (nitrogen), were completely control all stage of citrus mealybug (Planoccous citri) for 4hr fumigation at 13°C. These applications meet the quarantine guidelines and protocols in terms of efficacies to target pest and safety concern as well as satisfactions of consumers showing no damages to imported bananas. Extensively, this cost effective EF technology could be acceptable to other fruit and vegetable commodities to reduce the fumigation costs and green house gas (CO2).

이 연구는 우리나라 교정시설 소장의 바람직한 리더십과 기관장으로서 소장이 갖추어야 할 핵심 역량을 제시하고자 수행되었다. 2000년대 이후 교정행정을 둘러싼 많은 변화와 함께 소장의 리더십도 변화의 필요성이 제기되어 왔으나 이에 대한 연구나 대중의 관심은 거의 없었다. 소장은 교정시설을 운영함에 있어 다양한 범위의 업무를 수행하고 있으므로 기관의 리더의 역량이 교정행정의 목표를 달성하는데 있어 큰 역할을 한다. 하지만 현재까지 교정행정에 있어서 연구의 중심은 수용자 교정교화 및 사회복귀를 위한 프로그램의 효과성 및 수용관리 측면에 집중되어 왔다. 수용관리를 책임지는 교정시설의 소장은 교정시설과 직원, 수용자를 통제하고 영향력을 발휘하는 권위적인 인물로 인식되어 왔다. 지금까지 교정행정에서 대부분의 소장은 그동안의 근무경험에서 얻은 폭넓은 지식과 다양한 경험을 통해 기관이 직면하는 다양한 이슈들에 대한 답과 방향을 제시하는 거래적 리더십의 특성을 보이는 것이 일반적이었다. 이러한 거래적 리더십은 상대적으로 안정적이었던 과거 교정행정 환경에서는 효과적이었으나, 최근 교정행정은 과거의 경험에 의존해서는 해결할 수 없는 새로운 문제들이 발생하고 있다. 따라서 이제는 교정시설 소장들의 리더십도 기존의 거래적 리더십에서 경험에 의존하기 보다는 원칙에 기초하여 문제를 처리하고 동기부여를 통해 공동의 역량으로 해결책을 찾아나가는 변혁적 리더십으로의 방향 선회가 필요하다. 향후 소장이 교정시설의 리더로서 기획, 인사관리, 지시, 통제와 관련한 역량을 개발할 수 있도록 장기적 관점에서의 지원이 필요하며, 교정시설 소장의 리더십 향상을 위해서는 소장 리더십의 중요성에 대한 인식 개선, 리더십 관련 교육훈련 체계 확충, 효과적인 소장의 리더십에 대한 가이드 라인 확립 등이 무엇보다도 필요하다.

The current study aims to propose a reorganization plan for the national emergency management system to improve the current organizational structure for responding to national disasters and emergency situations. As a theoretical framework, the current study identified four key elements of successful disaster response systems: responsiveness, controllability, expertise, and devotedness. On the basis of the four key elements of disaster response systems, this study critically reviewed the current state of the organizational structure of the Korean national emergency response system by discussing the issues inherent in the current structure and by doing a comparative analysis of two high-profile national disaster cases—the Sewol ferry disaster in 2014 and the Gwangsan Rescue of buried people in 2013. Then, this study proposed the reorganization plan for the national disaster response system in which the NEMA is under direct control of the Prime Minister of Korea. It coordinates and controls the related government departments, such as the police, maritime police, and military during the national disaster and emergency situation. This study also proposed a reorganizational plan for the regional disaster response system in Korea. Finally, it was suggested that the status of firefighters should be elevated to the national public servant level in order to achieve organizational efficiency and solve existing problems that come from the current separated systems.

A membrane module including grid was designed and introduced to MBR (membrane bio-reactor) for the purpose of better control of membrane fouling. It could be anticipated that the grid enhances the shear force of fluid-air mixture into the membrane surface by even-distributing the fluid-air to the membrane module. As MLSS concentration, packing density which is expressed in the ratio of the housing and the cross-sectional area of membrane fibers (Am/At) and air-flow rate were changed, membrane foulings were checked by monitoring fouling resistances. The total fouling resistance (Rc+Rf) without grid installation (i.e., control) was 2.13×1012 m-1 , whereas it was reduced to 1.69×1012 m-1 after the grid was installed. Regardless of the grid installation, the Rc+Rf increased as the packing density increased from 0.09 to 0.28, however, the increment of resistance for the grid installation was less than that of the control. Increase in the air flow rate did not always guarantee the reduction of fouling resistance, indicating that the higher air flow rate can partially de-flocculate the activated sludge flocs, which led to severer membrane fouling. Consequently, installation of grids inside the housing have brought a beneficial effect on membrane fouling and optimum air flow rate is important to keep the membrane lowering fouling.

Bloom of small centric diatom Stephanodiscus is quite occasional in winter season in temperate freshwater ecosystems. It often leads to degradation of water quality and affects the quality of supplied drinking water. In a previous study, we have found that naphthoquinone (NQ) 4-6 derivate is an effective tool for efficient mitigation of natural S. hantzschii blooms. In the present research, polylactide (PLA) and agar foam were used as immobilized agent for NQ 4-6 to improve the efficiency of NQ 4-6 compound releasing process for its application under various field conditions. Mesocosm experiments at 10 ton scale suggested that the abundance of S. hantzschii was continuously increased in the control and upon treatment of the mesocosm with immobilized NQ 4-6 from PLA and agar foam. Their algicidal activities were 78.8% and 77.1%, respectively, on S. hantzschii after 10 days. In the mesocosm experiments, the dynamics of biotic (bacteria, HNFs, ciliates, zooplankton) and abiotic (water temperature, dissolved oxygen, pH, conductivity, nutrients) factors remained unaffected. They exhibited similar trends in the control and treatment groups. Therefore, the immobilized NQ 4-6 from PLA and agar foam has potential to be used as an alternative algicidal substance to effectively mitigate natural S. hantzschii blooms under various field conditions. In addition, it not only can be used to control S. hantzschii, but also is an effective technique. The immobilized NQ 4-6 showed stable controlled release in desired system.

This paper addresses the problem of how to effectively use virtual reality(VR) for improving the quality of safety training systems. As the working environment and the working system in the industry are more and more complex and large-scaled, the concern with system safety is accordingly growing. Safety training systems are regarded as an effective way for increasing workers’ interest in system safety and enhancing their ability of preventing and handling accidents/incidents. Recently, it has been reported that VR would be effectively used for improving the quality of safety training systems, with its technically specialized features. However, little attention has been given to the problem of how to effectively use VR for safety training systems. In order to make the best use of new technology such as VR, it is important to examine its advantages and disadvantages and the contexts to which its use can be beneficial. This paper firstly reviews the current status of safety training systems and the use of VR for safety training systems in the inside and outside of the country. Next, we summarize the interview with safety managers in four manufacturing companies, which was conducted to understand the requirements of stake-holders of the issue. Based on the review and the interview, we suggested the ways of using VR in safety training systems in an effective manner. They are described from the four perspectives: development and maintenance cost, lack of specialized workers, design of accident scenarios used with VR, and empirical demonstration of the effectiveness of VR in safety training.

We investigate the change of leaf chlorophyll content according to iron content in brown rice when cultivated on the iron limited solid MS medium. By cultivating wild-type and transgenic brown rice in a solid MS medium, we confirmed that iron deficiency chlorosis did not occur in MS media which were contained over 20% of iron content compared to normal MS condition. After selecting twenty kinds of Korean rice varieties, those brown rice were cultivated in solid MS media which were contained from 0 to 15% of iron content compared to normal MS condition then the leaf chlorophyll content was measured. The leaf chlorophyll content was changed according to iron content in brown rice when cultivated in solid MS medium which was contained 0 and 5% of iron content,. There was a strong correlation between iron content in brown rice and leaf chlorophyll content cultivated in solid MS medium with 5% of Fe content. Therefore we expect that analysis of leaf chlorophyll content after cultivated on MS medium with 5% iron content compared to normal MS media condition will be more simple and effective method to screening high iron content brown rice without measurement of iron content.

This study was conducted to investigate optimum conditions for mass production of ntagonistic microbes Alcaligenes sp. HC12. Alcaligenes sp. HC12 had a potent biological control agent to control browning disease caused by Pseudomonas agarici. Alcaligenes sp. HC12 markedly showed the antagonistic activity against Pseudomonas agarici, the most destructive pathogen of cultivated mushrooms. To define the optimum conditions for the mass production of the Alcaligenes sp. HC12, we have investigated optimum culture conditions and effects of various nutrient source on the bacterial growth. The optimum initial pH and temperature were determined as pH 9.0 and 30o, respectively. The optimal concentration of medium elements for the growth of pathogen inhibitor bacterium(Alcaligenes sp. HC12) was determined as follows: 0.5% dextrine, 1.5% yest extract, 1.0% NaNO3, 0.5% KH2PO4, and 1.5% asparagine.

This study investigates important parameters used to determine an effective peak ground acceleration (EPGA) based on the characteristics of response spectra of historical earthquakes occurred at Korean peninsula. EPGAs are very important since they are implemented in the Korean Building Code for the seismic design of new structures. Recently, the Gyeongju earthquakes with the largest magnitude in earthquakes measured at Korea took place and resulted in non-structural and structural damage, which their EPGAs should need to be evaluated. This paper first describes the basic concepts on EPGAs and the EPGAs of the Gyeongju earthquakes are then evaluated and compared according to epicentral distances, site classes and directions of seismic waves. The EPGAs are dependant on normalizing factors and ranges of period on response spectrum constructed with the Gyeongju earthquake records. Using the normalizing factors and the ranges of period determined based on the characteristics of domestic response spectra, this paper draw a conclusion that the EPGAs are estimated to be about 30 % of the measured peak ground accelerations (PGA).

The beneficial effects of EM on plant growth, yield, quality in agriculture have been consistently demonstrated. In this study, EM of four types used is Lactobaillus sp., saccharomyces cerevisiea, Rhodobacter sp. and Bacillus sp.. Bacillus sp. inhibited Mycelium growth of the oyster mushroom in agar plate. Bacillus sp. is known to suppress plant pathogenic microorganism in soil. The other three type of EM did not inhibit mycelium growth of oyster mushroom. Also when filtering media of Lactobacillus sp. and saccharomyces cerevisiea cultivation add to liquid media(PDB) of oyster mushroom, mycelium growth was a little faster than control. In the column test, Mycelium growth of the medium inoculated with 0.5% saccharomyces cerevisiea was faster than the control. In the substrate inoculated Rhodobacter sp. was similar to the control. In the substrate inoculated Lactobacillus sp. of higher concentration, mycelium growth of the oyster mushroom was showed late than control.

MBR공정에서 물리적 세정방법인 공기폭기(Aeration)는 장기간 막성능을 유지시키기 위한 주요 핵심 방법으로, 기존의 연구들은 산기관의 성능을 극대화시켜 공기세정을 최적화시키려 하였다. 분리막의 효율적인 슬러지 탈리를 위해 폭기위 치⋅시간⋅균일 배출성 및 데드존(Dead Zone) 감소 등에 대한 다양한 연구들이 진행되어 왔으나, 이를 통한 더 이상의 성능향상은 기대하기 어려운 상황이다. 본 연구에서는 기존의 분리막 모듈을 개량하여 공기폭기의 효과를 극대화 하는 연구를 진행하였다. 선행연구로 진행된 Lab-scale실험을 기반으로, Pilot-scale 장치를 세팅하여 장기평가 및 분석 등을 진행하였다. 동일 site에서 개량모듈한 것과 그렇지 아니한 것에 대하여 비교분석하였다.

On Tuesday, January 17, 1995, an earthquake of magnitude 7.2 struck the Port of Kobe. In effect, the port was practically destroyed. After a hazard investigation, researchers reached a consensus to adopt a performance-based design in port and harbor structures in Japan. A residual displacement of geotechnical structures after an earthquake is one of the most important engineering demands in performance-based earthquake-resistant design. Thus, it is essential to provide reliable responses of geotechnical structures after an earthquake through various techniques. Today, a nonlinear explicit response history analysis(NERHA) of geotechnical structures is the most efficient way to achieve this goal. However, verification of the effective stress analysis, including post liquefaction behavior, is difficult to perform at a laboratory scale. This study aims to rigorously verify the NERHA by using well-defined field measurements, existing numerical tools, and constitutive models. The man-made, Port Island, in Kobe provides intensive hazard investigation data, strong motion records of 1995 Kobe earthquake, and sufficient engineering parameters of the soil. Two dimensional numerical analysis was conducted on the caisson quay wall section at Port Island subjected to the 1995 Kobe earthquake. The analysis result matches very well with the hazard investigation data. The NERHA procedure presented in this paper can be used in further studies to explain and examine the effects of other factors on the seismic behavior of gravity quay walls in liquefiable soil areas.

이 연구는 선원안전(재)교육과정의 교육대상, 교육내용, 교육예상인원 및 외국 교육기관의 교육운영방법을 분석하여 국내 선원안전(재)교육과정의 효율적인 운영방안을 제안하였다. 향후 우리나라 전체 선원 37,000여명이 5년마다 주기적으로 선원안전(재)교육을 수료하여야 하므로 선원의 편의를 위하여 STCW 협약에서 인정하는 선상에서의 교육을 활성화하고 선상교육프로그램을 표준화하여 육상교육을 축소할 뿐만 아니라 선원 안전교육의 지속적인 개선을 위해 교육 분야 투자가 지속적으로 진행되어야 한다. 또한 국내 선원안전(재)교육과정과 STCW협약과의 차이점을 개선할 수 있는 방안을 검토할 필요가 있으며, 선원이 안전(재)교육을 적시에 이수할 수 있는 환경을 마련하기 위하여 안전교육시설 및 가상현실 교육프로그램 개발에 대한 투자가 이루어져야 한다.