지난 2011년부터 수처리용 멤브레인 개발을 진행하던 롯데케미칼은 침지식 PVDF 중공사 멤브레인을 기반으로 MBR을 포함하는 수처리 시장에 진출하기 위하여, 2015년 2월 삼성 SDI의 관련 기술 및 연구장비, 파일럿을 인수하여 기술개발과 실적확보를 위한 연구를 지속적으로 수행하였다. 롯데케미칼의 침지식 멤브레인은 평균 기공크기가 30 nm의 한외여과막으로서 고강도 멤브레인과 저에너지형 멤브레인의 두 종류로 구성되어 있다. 특히, 저에너지형 멤브레인은 고강도 대비 30%의 fiber 무게를 감소시킴으로서 적은 세정용 공기 소비량에서도 세정효율을 유지할 수 있도록 하였다. 또한 내경의 단면적을 약 90% 정도 향상시켜 중공사막 내부의 유체저항을 최소화시켰다.

The purpose of this study was to determine factors related to the consumption of energy drinks among male and female high school students in Daejeon. The research data, derived from the self-administered questionnaire method, was collected from 664 students in fifteen high schools during the spring of 2016. A total of 542 complete questionnaires were analyzed (response rate: 79.8%). Approximately 73% of the students self-reported having consumed energy drinks, with a greater percentage of male (as opposed to female) students self-reporting as having done so. The most common reasons given for the consumption of energy drinks were to stay awake (54.8%), the good taste of the drink (28.0%), to concentrate during studying (17.2%), and to relieve fatigue (16.9%). The adverse effects were palpitation (59.3%), insomnia (35.6%), and experiencing difficulty in waking up (30.5%). More than two in three (67.8%) students who experienced adverse effects still consumed energy drinks. The average level of health consciousness was lower than 3 out of 5 points. The results of the logistic regression analyses indicated a positive relationship between monthly allowance (OR=1.01 for male and female students) and the consumption of energy drinks by both male and female students. Among the male students, freshmen (OR=0.23) were less likely to have consumed energy drinks than juniors. Male students’ sleeping hours (OR=0.65) and perceived school life satisfaction scores (OR=0.63) were negatively associated with the consumption of energy drinks. In the case of female students, study hours (OR=0.83) and energy drinks consumption were negatively related. These factors affecting energy drinks consumption could be considered in the development of dietary education programs aimed at protecting high school students from the adverse health impacts of energy drinks

Gas hydrate desalination process is based on a liquid to solid (Gas Hydrate, GH) phase change followed by a physical process to separate the GH from the remaining salty water. The GH based desalination process show 60.5-90% of salt rejection, post treatment like reverse osmosis (RO) process is needed to finally meet the product water quality. In this study, the energy consumption of the GH and RO hybrid system was investigated. The energy consumption of the GH process is based on the cooling and heating of seawater and the heat of GH formation reaction while RO energy consumption is calculated using the product of pressure and flow rate of high pressure pumps used in the process. The relation between minimum energy consumption of RO process and RO recovery depending on GH salt rejection, and (2) energy consumption of electric based GH process can be calculated from the simulation. As a result, energy consumption of GH-RO hybrid system and conventional seawater RO process (with/without enregy recovery device) is compared. Since the energy consumption of GH process is too high, other solution used seawater heat and heat exchanger instead of electric energy is suggested.

전 세계적으로 대두되고 있는 물 부족 현상을 해결하기 위하여 하수재이용과 해수담수화 공정의 관심이 높아지고 있다. 특히, 정삼투-역삼투 융합공정은 해 수를 유도용액으로, 하수처리수를 유입수로 하여 정삼투 공정에서 유도용질의 회수 없이 희석된 해수를 역삼투 공정을 통해 하수재이용과 해수담수화를 동시 에 달성할 수 있는 공정으로 최근 각광받고 있다. 이 융합공정은 정삼투 공정과 역삼투 공정의 단점을 상호 보완하는 저에너지 공정으로 차세대 해수담수화 시장을 이끌어 나갈 것으로 판단된다. 따라서, 본 연구에서는 정삼투, 역삼투 막의 특성과 융합공정의 운영인자를 반영한 공정모사를 통하여 정삼투-역삼투 융합 공정의 소비에너지를 최소화 시킬 수 있는 최적 운영조건을 도출하고자 하였다.

최근 숲길 이용자들이 폭발적으로 증가하고 있으며, 이에 따라 각종 안전장치를 위한 비용 또한 급격히 증가하고 있다. 그럼에도 다른 사고와 달리 심장관련 사고는 줄지 않고 있어 숲길에 제공되는 난이도 정보의 개선방안에 대한 연구를 지리산 둘레길을 대상으로 진행하였다. 기존 숲길에 대한 난이도 정보는 숲을 관리하는 특정인에 의한 경험적 난이도 또는 단순히 거리를 바탕으로 한 난이도를 3~5단계로 구분하여 제공하고 있어 탐방객이 실제 느끼는 난이도와는 괴리감이 있었다. 본 연구에서는 실질적인 에너지소모량을 바탕으로 한 난이도 제공 가능성을 분석하였다. 거리와 경사에 따른 산소소모량의 계산은 숲길 각 구간에 대한 절대적 비교뿐만 아니라 상대적 비교가 가능하였으며 특정 구간의 운동강도를 간단히 표현하는데 효과적이었다. 아울러 시·종점의 변화에 따른 운동량 변화를 쉽게 확인할 수 있었다. 구간별, 산행방향별 운동량에 대한 표준화된 사전 정보제공은 심장관련 사고의 사전예방 효과가 있을 것으로 판단된다.

역삼투법 해수담수화 기술은 에너지 소모 및 농축수 처리 문제로 인하여 기술 활용의 보급에 제한이 있는 실정이다. 해수·하수를 유도용액과 원수로써 사용하는 정·역삼투 융합공정은 별도의 유도용액이 필요하지 않으며 희석된 해수가 역삼투 공정의 원수로써 사용되기 때문에 일반적인 역삼투법 해수담수화 기술보다 낮은 압력에서 운전된다. 또한 역삼투 공정 후단에 정삼투 공정을 추가시킴으로써 농축수를 희석시킬 수 있으며 이로써 농축수 배출로 인한 문제점을 최소화 시킬 수 있다. 현재 국외에서는 Modern water, Porifera사 주도로 정삼투 모듈 개발 및 실용플랜트 개발이 이루어지고 있으며, 국내의 경우 FOHC 연구단에서 해당 공정의 기본 메커니즘 및 실용화에 관한 연구가 이루어지고 있다.

The Laplace Transform solution is used as a mathematical model to analyse the thermal performance of the building constructed using different wall materials. The solution obtained from Laplace Transform is an analytical solution of an one dimensional, linear, partial differential equation for wall temperature profiles and room air temperatures. The main purpose of the study is showing the detail of obtaining solution process of the Laplace Transform. This study is conducted using weather data from two different locations in Korea: Seoul, Busan for both winter and summer conditions. A comparison is made for the cases of an onoff controller and a proportional controller. The weather data are processed to yield hourly average monthly values. Energy consumption load is well calculated from the solution. The result shows that there is an effect of mass on the thermal performance of heavily constructed house in mild weather conditions such as Busan. Building using proportional control experience a higher comfort level in a comparison of building using on-off control.

It is essential to decrease energy consumption and excess sludge to economically operate sewage treatment plant. This becomes more important along with a ban on sea dumping and exhaustion of resource. Therefore, many researchers have been study on energy consumption reduction and strategies for minimization of excess sludge production from the activated sludge process. The aeration cost account for a high proportion of maintenance cost because sufficient air is necessary to keep nitrifying bacteria activity of which the oxygen affinity is inferior to that of heterotrophic bacteria. Also, additional costs are incurred to stabilize excess sludge and decrease the volume of sludge. There were anoxic, aerobic, membrane, deairation and concentration zone in this MBR process. Continuous aeration was provided to prevent membrane fouling in membrane zone and intermittent aeration was provided in aerobic zone through ammonia sensor. So, there was the minimum oxygen to remove NH4-N below limited quantity that could be eliminated in membrane zone. As the result of this control, energy consumption of aeration system declined by between 10.4 % and 19.1 %. Besides, we could maintain high MLSS concentration in concentration zone and this induced the microorganisms to be in starved condition. Consequentially, the amount of excess sludge decrease by about 15 %.

In this study, the actual energy consumption of the secondary side of district heating system(DHS) with different hot water supply temperature control methods are compared. Two methods are outdoor temperature reset control and outdoor temperature predictive Control. While outdoor temperature reset control has been widely used for energy savings of the secondary side of the system, the results show that outdoor temperature predictive control method saves more energy. In general, outdoor temperature predictive control method is lowering the supply temperature of hot water, and it reduces standby losses and increases overall heat transfer value of heated spaces due to more flow into the space. During actual energy consumption monitoring, outdoor temperature predictive control method saves about 19.1% when it compared to outdoor temperature reset control method. Also, it is found that when partial load condition, such as daytime, the fluctuation of hot water supply temperature with outdoor temperature reset control is more severe than outdoor temperature prediction control. So, it proves that outdoor temperature prediction control is more stable even at partial load conditions.

This project is mainly related to evaluation of total energy consumption of low energy house, the exterior envelope of which was wholly composed of structural insulated panels(SIP). The U-value of applied SIP was in the range of 0.189 to 0.269W/㎡․K and the U-value of pair glass from 0.78 to 1.298W/㎡․K was applied for window dependent to its function respectively. For comparison of total energy performance, the energy simulation for pilot house was performed to compare with the control house having insulation criteria of Korean building regulation in 2009. Based on simulation of dynamic energy performance, the pilot house saved 48.3% of annual energy consumption while the control house in 2009 consumed as 85.7GJ/y. In case of heating, the result showed that the energy saving ratio amounted to 76.7%. For CO₂ emission, the pilot house diminished approximately 35.4% from 6,208.4kgCO₂ to 4,009.2kgCO₂. In payback period to early investment, it was analyzed the pilot house took 7.8 years, when the low energy house built by other insulation method with same thermal perfusion took 11.5 years. From this result, it is considered that the SIP is more effective, economic to Green Home application.

Most of steam power plant in Korea are heating the feed water system to prevent freezing water flowing in the pipe in winter time. The heating system is operated whenever the ambient temperature around the power plant area below 5 degree Centigrade. But this kind of heat supplying system cause a lot of energy consuming. If we think about the method that the temperature of the each pipe is controled by attaching the temperature measuring sensor like RTD sensor and heat is supplied only when the outer surface temperature of the pipe is under 5 degree Centigrade, then we can save a plenty of energy. In this study, the computer program package for simulation is used to compare the energy consumption load of both systems. Energy saving rate is calculated for the location of Youngweol area using the data of weather station in winter season, especially the January' severe weather data is analyzed for comparison. Various convection heat transfer coefficients for the ambient air and the flowing water inside the pipe was used for the accurate calculation. And also the various initial flowing water temperature was used for the system. Steady state analysis is done previously to approximate the result before the simulation. The result shows that the temperature control system using RTD sensor represents the high energy saving effect which is more than 90% of energy saving rate. Even in the severe January weather condition, the energy saving rate is almost 60%.

This study was performed to investigate the consumption of coffee beverages and energy contribution ratios of coffee beverages and accompanying snacks by college students in Deajeon City and Chungnam Province in Korea. Questionnaire survey, dietary survey, and snack survey using food record method during 3-days were carried out. As a result, we found that 86.9% of male students and 75.6% of female students consumed coffee beverages usually, with no differences between the two groups. However, the frequency of coffee beverages consumed by female students out-numbered that of male students by 1 cup a day to 1-2 cups a week (p<0.05). Furthermore, male students most likely consumed coffee beverages at schools or academies, but female students consumed them at coffee shops (p<0.01). The reasons male students gave to consume coffee beverages were for scent, taste, fatigue, and to stay awake. Similarly, the reasons female students gave to consume coffee beverages were for scent, taste, habit, and to stay awake (p<0.01). Fully 58.1% of male students and 80.0% of female students ate snacks along with coffee beverages (p<0.01). Most male students substituted a coffee beverage and accompanying snack for a regular meal once a month. Female students were doing it at most 2-3 times a month (p<0.05). The mean daily dietary energy intake of male students was 1,924 kcal/d, and of female students was 1,518 kcal/d (p<0.001), which both were below the estimated energy requirements. Male students obtained 285.6 kcal/d and female students obtained 289.5 kcal/d from coffee beverages and accompanying snacks. There was a significant different in dietary intake of energy (p<0.05), calcium, and iron (p<0.001) for each ratio of reference intake between male and female students. The students who ate larger amounts of coffee beverages and accompanying snacks consumed less dietary energy, protein, calcium, and iron, respectively (p<0.05). These results show that many students consume coffee beverages regularly and obtain large amounts of energy from coffee beverages and accompanying snacks. It also shows that student's dietary nutrient intake tends to be poorer, as he or she obtains more energy from coffee beverages and accompanying snacks. Therefore, it is critical to monitor the influence of consumption of coffee beverages and accompanying snacks on the dietary nutrient intakes and health of college students, and to provide nutrition education about the proper consumption of coffee beverages and accompanying snacks based on scientific evidence.

Four different buildings having various wall construction are analyzed for the effect of wall mass on the thermal performance and inside building air and wall temperature transient and also for calculating the energy consumption load. This analytical study was motivated by the experimental work of Burch et al. An analytical solution of one-dimensional, linear, partial differential equations is obtained using the Laplace transform method, Bromwich and modified Bromwich contour method. A simple dynamic model using steady state analysis as simplified methods is developed and results of energy consumption loads are compared with results obtained using the analytical solution. Typical Meteorological Year data are processed to yield hourly average monthly values. This study is conducted using weather data from two different locations in Korea: Daegu having severe weather in summer and winter and Jeju having mild weather almost all year round. There is a significant wall mass effect on the thermal performance of a building in mild weather condition. Buildings of heavyweight construction with insulation show the highest comfort level in mild weather condition. A proportional controller provides the higher comfort level in comparison with buildings using on-off controller. The steady state analysis gives an accurate estimate of energy load for all types of construction. Finally, it appears that both mass and wall insulation are important factors in the thermal performance of buildings, but their relative merits should be decided in each building by a strict analysis of the building layout, weather conditions and site condition.

The purpose of this study were to investigate the state of indoor environmental factors and energy consumption during winter in residential houses and to analyze factors which influenced this environment. Energy consumptions and indoor environmental factors of this survey were conducted in 21 houses(apartment, 11 and detached houses,10) between December, 2010 and February, 2011 which measured energy consumptions and indoor environmental factors as well as kept records of interviews with residents and other related factors. The results obtained were as follows. Indoor environmental factors which were found to influence apartment houses higher than detached houses. The average gas consumption of detached houses(90.98³) was higher than that of apartment houses(76.33³). Gas consumption showed positive correlations to temperature and carbon dioxide in the residential houses. The mean concentration of PM₁₀, and CO₂ in large family were higher than those of small family. We found that the more gas consumption, the higher concentration of PM₁₀, CO₂ and temperature(p<0.01).

A steady-state analysis and a simple dynamic model as simplified methods are developed, and results of energy consumption loads are compared with results obtained using computer to evaluate the analytical solution. Before obtaining simplified model a mathematical model is formulated for the effect of wall mass on the thermal performance of four different houses having various wall construction. This analytical study was motivated by the experimental work of Burch et al. An analytical solution of one-dimensional, linear, partial differential equation for wall temperature profiles and room air temperatures is obtained using the Laplace transform method. Typical Meteorological Year data are processed to yield hourly average monthly values. This study is conducted using weather data from four different locations in the United States: Albuquerque, New mexico; Miami, Florida; Santa Maria, California; and Washington D.C. for both winter and summer conditions. The steady state analysis that does not include the effect of thermal mass can provide an accurate estimate of energy consumption in most cases except for houses #2 and #4 in mild weather areas. This result shows that there is an effect of mass on the thermal performance of heavily constructed house in mild weather conditions. The simple dynamic model is applicable for high cycling rates and accurate values of inside wall temperature and ambient air temperature.

In this study the real situation of apartment house in seoul is reproduced with multi-zone modeling program CONTAM2.4. This model include disinfection system which is consist of dilution, filtration, UVGI(ultra violet germicidal irradiation). It's energy consumption was also analyzed through the linked model of CONTAM and TRNSYS according to the combination of components. The comparison of total energy consumption through energy analysis revealed that adjusting the air change rate of the UVGI air sterilizer to maintain the same indoor microbe removal capability was more advantageous in terms of energy consumption.

이산화탄소는 기후변화를 야기시키는 주요 온실가스이다. 본 연구는 춘천시, 강릉시, 서울시 강남구 및 중랑구를 대상으로 토지이용유형별 식생관리에 기인한 에너지소비 및 탄소방출을 잔디깎기, 전정, 관수, 시비, 살충제시용 등의 식생관리실태를 면담설문 및 일부 실측을 통해 파악하였다. 동일 토지이용유형 내 식생관리강도는 대체로 도시간 및 구간 통계적으로 유의한 차이가 없었다. 수목관리에 의한 연간 총탄소방출량은 토지이용유형에 따라 단위피도면적당 36.0~209.7g/m2로서 교통용지에서 가장 많았다. 잔디관리에 의한 연간 총탄소방출량은 단위잔디면적당 7.4~69.3g/m2로서 공원에서 가장 많았다. 이들 총탄소방출량 중 수목의 경우 전정이 토지이용유형에 따라 96.8~99.7%를, 잔디의 경우 잔디깎기가 91.9~100%를 각각 차지하였다. 도시식생의 연간 순탄소흡수를 최대화하기 위해서 가로수의 전정과 공원 내 잔디깎기에 의한 탄소방출을 최소화할 식재계획 및 관리가 요구된다.

The neoclassical economic supporters have suggested that foreign direct investment and raw material (e.g., coal, electricity, gas, and oil) are critical economic growth inputs. Few previous studies have analyzed the relationship between foreign direct investment and energy consumption on economic growth. However, existing studies usually have applied the frequentist inference. The limitation of the frequentist inference is that, if the coefficient of the independent variable is not yet significant, then conclusions might be unreliable. By applying the Bayesian approach, the main aim of this study is to revisit the impact of foreign direct investment, electricity consumption, and urbanization on economic growth in six ASEAN countries from 1980 to 2016. The obtained outcome shows that the impact of electricity consumption is evident and positive on economic growth in both frequentist and Bayesian inferences. However, the influence of foreign direct investment is not identified by frequentist inference, while Bayesian inference provides evidence that foreign direct investment is a moderately positive impact on economic growth. The empirical result from Bayesian inference contributes to the literature on foreign direct investment modeling and could be of significant importance for a more efficient foreign direct investment attracting and achieve sustainability in the long-term.