Recently, uncertainty of demand and supply for energy has expanded as energy market change rapidly. Rapid accumulation storing of cold heat is a method for decreasing the gap between demand and supply of time, quantity and quality of heat energy. It is stored rapidly when electric power is on. And cold heat energy in heat is phase change material (PCM) heat storage is used when electric power is off. Porous media for cold heat is PCM. The present study has been conducted for improving performance of cold heat storage in refrigerator using characteristics on laten heat and phase change of PCM. This study provide basic data to improve performance of cold heat using characteristic of PCM. Also, this study predicts and measures specific points in PCM heat storage during process of phase change.

전북 부안군 변산면에서 야간 채집한 옥색긴꼬리산누에나방의 발육특성 및 기주식물을 탐색하기 위하여 실내사육을 실시한 결과 채집후 4~5일이내에 산란을 하였고, 암컷 한 마리당 평균산란수는 122.8개였고, 일평균산란수는43.1개였으며, 난기간은 8.3일이었다. 까치박달나무를 먹이로 사육한 옥색긴꼬리산누에나방 유충은 5회 탈피하였고,1령충은 검정, 2령충은 밤색, 3~5령충은 초록색으로 색채변이가 있었다. 유충 발육기간은 1령 3.7일, 2령 6.6일,3령 11.0일, 4령 6.6일, 5령 24.5일이었고, 번데기는 나뭇잎을 엮어 그안에 고치를 짓고 번데기가 되었으며, 21.2일정도 경과하여 성충으로 우화하였다. 옥색긴꼬리산누에나방 유충의 기주식물 선호성을 분석하기 위하여 까치박달나무, 오리나무, 참나무, 단풍나무 잎을 먹이로 각각 개체사육을 실시하고, 한편으로 한 용기에 4가지 잎을 넣고,선호성을 조사한 결과 오리나무와 까치박달나무만 섭식을 하였고, 참나무와 단풍나무잎은 거의 섭식하지 않았으며,오리나무를 가장 선호하였고, 발육기간도 가장 빠르고, 사망률도 적었다.

2015년부터 2016년까지 전북지역 오디 생산용 뽕나무에서 점박이응애(Tetranychus urticae Koch)와 명주달팽이(Acusta despecta Sowerby) 2종을 포함하여 총 33종의 해충이 조사되었다. 그 가운데 뽕나무총채벌레(Pseudodendrothrips mori Niwa)를 포함한 8종이 주요 해충 으로 분류되었다. 수확 전에는 총 25종이 조사되었는데, 그 가운데 뽕나무총채벌레(P. mori), 뽕나무이(Anomoneura mori Schwarz), 뽕나무깍지 벌레(Pseudaulacaspis pentagona Targioni Tozzetti), 뽕나무애바구미(Baris deplanata Roelofs), 뽕나무가지나방(Menophra atrilineata Butler), 점박이응애(Tetranychus urticae Koch) 6종이 주요 해충으로 분류되었다. 수확 후에는 총 25종이 조사되었는데, 그 가운데 뽕나무총채벌레(P. mori), 뽕나무깍지벌레(P. pentagona), 뽕나무명나방(Glyphodes pyloalis Walker), 미국흰불나방(Hyphantria cunea Drury), 점박이응애(T. urticae) 5종이 주요 해충으로 분류되었다. 오디용 뽕나무에서 발생하는 해충은 조사지역에 따라 달랐으나, 뽕나무총채벌레 등 주요 해충 8종과 베짱이(Hexcacentrus unicolor Serville), 뽕나무노린재(Malcus Japonicus Ishihara et Hasegawa), 썩덩나무노린재(Halyomorpha halys stal), 오 리나무좀(Xylosandrus germanus Blandford), 나방류 4종(Bombyx mandarina Moore, Euproctis subflava Bremer, Acronicta major Bremer, Agrotis trifurca Butler) 및 명주달팽이(Acusta despecta Sowerby)는 모든 조사지역에서 발생되었다.

본 연구에서는 전산유체해석 기법을 이용하여 대용량 막여과 설비 유닛의 유량불균등 현상을 분석하고 이를 해결할 수 있는 개선방안을 도출하고자 하였다.

본 연구에서는 공급수의 Blending 및 ERD 적용을 통해 역삼투 공정의 소비전력량을 비교 분석하였다.

The purpose of this study is to inquire original design and character of dancheong in Yeongnamnu Pavilion which features unusual portraits of twisting dragons and four heavenly creatures. Its artistic value and originality can be found in the portraits of four heavenly creatures which are painted on the interior seonjayeon(fan shape rafter) and in the unique design of crossbeam meoricho(flower decorations on each side of pillars). Yeongnamnu’s crossbeam meoricho is janggu-meoricho type(meoricho with hourglass figure) with full-shape lotus and half-shape flower decorations. And it can be said that, dragon portrait painted on the border of lotus and flower decorations in green and yellow is a very unique style of dancheong, for the reason that it has scarcely been used before and ever since. The portrait of four heavenly creatures painted on each corner of seonjayeon is also found to be unique in design, for the reason that the design has rarely been used throughout history, with only two exceptions in mural tombs of Goguryeo and folding screen in Injeongjeon Hall of Changdeokgung Palace . With its unique and authentic feature along with its rarity in number, the portrait of four heavenly creatures painted on Yeongnamnu can be considered as quite symbolic and important.

본 연구에서는 SWRO공정의 Feed Dilution에 따른 SWRO Permeate Flow의 민감도 분석 및 Hybrid Module Design을 통한 개선방안을 검토하였다.

The characteristics of the turbulent MHD channel flows are analysed within the elliptic blending    model. The evaluation of additional terms representing the MDH interactions in the transport equation for the turbulent kinetic energy and dissipation rate is carried out firstly. And then, the improvement of model coefficients for the additional terms is achieved. Regardless of the magnetic field orientation, perpendicular and parrel to the main flow, the model coefficients for the additional terms are not changed to maintain the generality of the present model. The prediction results are directly compared to the DNS data to assess the performance of the present model.

The Saemangeum watershed is required to manage water pollution effectively but the effect of liquid manure (LM) on soil and water quality in the basin is not clearly identified as yet. This study aims at assessing the effect on soil of a rice field and water quality of water bodies near the rice field during rice-crop time period to find out the effect of LM, the effect of rainfall, and the effect of rice-crop environment on soil and water quality by analyzing data of nitrogen components. As a result of the LM distribution, NO3-N was much higher than other N components in the entire soil layers and it was accelerated by rainfall right after the LM distribution. Compared to chemical fertilizer (CF), LM was slightly affected but still influenced on the surface water quality. During weak rainfall, low nitrogen concentration in topsoil was resulted as NH3-N decreased and Org-N and NO3-N increased. NO3-N concentration in the water of irrigation canals increased with time. During intensive rainfall, NO3-N and Org-N of the soil were measured highly in the submerged condition, while the water quality of the rice field was lower due to flooding into the irrigation canal as well as the growth of the rice plants. Also, total nitrogen was increased more than 7 times and it showed serious water quality deterioration due to LM and excessive fertilizer distribution, and rainfall during all rice-crop processes. The effect of LM on water quality should be studied consistently to provide critical data while considering weather condition, cropping conditions, soil characteristics, and so on.

본 연구에서는 막여과공정, 오존접촉공정, 활성탄흡착공정, 자외선소독공정 등이 계층형으로 배치된 정수처리 실증시설의 설계 및 운영을 통해 수직형 정수 처리시설의 최적 설계/운영방안을 도출하고자 하였다.

Polytetrafluoroethylene (PTFE) membrane has high resistance to chlorine, which is a great advantages in chemical cleaning to recover water flux during membrane processes in drinking water systems. A humic kaolin water with approximately 4 mg/L of DOC and 10 NTU of turbidity was prepared as a feed water. Coagulation pretreatment with or without settling was applied. The coagulation with settling showed the greatest water production. The reduced flux was effectively recovered by NaOCl cleaning, i.e., 21% recovery by 50 mg/L of NaOCl cleaning and 49% recovery by 500 mg/L NaOCl cleaning. The images of SEM and AFM analyses were corresponded to the water flux variation. However, when the floc was accumulated on the membrane surfaces, the efficiency of NaOCl cleaning was substantially limited. In addition, dynamic contact angle became greater after cleaning, which indicates changes in characteristics of fouling layer such as surface hydrophobicity. Proper cleaning technologies during enhanced backwash using NaOCl would expand application of PTFE membranes in drinking water systems.

An algebraic model for turbulent heat fluxes is proposed on the basis of the elliptic blending equation. The algebraic model satisfies the temperature-pressure gradient correlation characteristics of near-wall region and the flow center region far away from the wall. That is, the turbulent heat flux conditions for both regions are connected by the solution of the elliptic blending equation. The predictions of turbulent heat transfer in a plane channel flow have been carried out with constant wall heat flux and constant wall temperature difference boundary conditions respectively. Also, the rotating channel flow with constant wall temperature difference is considered to test the applicability of the model. The prediction results show that the distributions of the turbulent heat fluxes and mean temperature are well captured by the present algebraic heat flux model.

In this study, the evaluation criteria of performance and applicability is developed to rank the combinatorial technologies for SWG (Smart Water Grid) system using AHP (Analytic Hierarchy Process) method. Security, safety, solution, suitability and sustainability which are goals of SWG technology, are used as upper level hierarchy elements. And three detailed elements for each upper level hierarchy are adopted as the lower level hierarchy. The weighted value which represents the importance of each element, could be determined through questionnaires accomplished by groups of specialists who are engaged in relevant waster industry and research area. To assess the accuracy of the evaluation criteria developed in this study, a simulation on four decision alternatives for smart water grid was carried out as an evaluation. Consequently which showed 90 % of accuracy.

Local Nusselt number and temperature field distribution within the compound duct with gap have been measured. Measurement of air and wall temperature span a range of gap width from 2mm to 6mm. Also, the Reynolds number is variated from 20,000 to 40,0000. In order to observe the correlations between gap width and turbulent heat transfer, the present measurement has tried to verify the enhancement effect of heat transfer when a gap exists within the compound channel. From this measurement, we could see that the pulsating flow has generated a strong turbulent flow mixing within the compound channel. And the turbulent flow mixing in the pulsating flow plays an effective role of enhancing the Nusselt number by making the fluid temperature uniformly within the compound channel.