• Title/Summary/Keyword: DAILY CYCLE

Search Result 337, Processing Time 0.024 seconds

Development of Adsorption Desalination System Utilizing Silica-gel (실리카겔을 이용한 흡착식 담수화 시스템 개발)

  • Hyun, Jun-Ho;Israr, Farrukh;Lee, Yoon-Joon;Chun, Won-Gee
    • 한국태양에너지학회:학술대회논문집
    • /
    • 2012.03a
    • /
    • pp.364-369
    • /
    • 2012
  • The development of solar thermal energy used adsorption desalination technology have been examined as a viable option for supplying clean energy. In this study, the modelling of the main devices for solar thermal energy used and adsorption desalination system was introduced. Silica gel type adsorption desalination system is considered to be a promising low-temperature heat utilization system. The design is divided into three parts. First, the evaporator for the vaporization of the tap water is designed, and then the reactor for the adsorption and release of the steam is designed, followed by the condenser for the condensation of the fresh water is designed. In addition, new features based on the energy balance are also included to design absorption desalination system. In this basic research, One-bed(reactor) adsorption desalination plant that employ a low-temperature solar thermal energy was proposed and experimentally studied. The specific water yield is measured experimentally with respect to the time controlling parameters such as heat source temperatures, coolant temperatures, system switching and half-cycle operational times. Desalination is processes that permeate our daily lives, but It requires substantial energy input, powered either from electricity or from thermal input. From the environmental and sustainability perspecives, innovative thermodynamic cycles are needed to produce the above-mentioned useful effects at a lower specific energy input. This article describes the development of adsorption cycles for the production of desalting effects. We want that this adsorption system can be driven by low temperature heat sources at 60 to $80^{\circ}C$, such as renewable, solar thermal energy.

  • PDF

Effects of Bisphenol A on Dams during Lactation Period in Rats (흰쥐 수유기에 경구투여된 Bisphenol A의 영향)

  • 김판기;유재홍
    • Korean Journal of Environmental Biology
    • /
    • v.21 no.2
    • /
    • pp.208-215
    • /
    • 2003
  • Bisphenol A (4,4'-isopropylidenediphenol, $C^{15}H_{16}O_{2}$) is the monomer used in the manufacture of polycarbonate. Polycarbonate, in turn, is used in a wide array of plastic products, with new applications continuously being developed. Also it has been used to produce epoxy resins and polycarbonate plastics for food container. This study was carried out to investigate the effects of bisphenol A on lactation period to dams and F1. Sprague-Dawley females were mated with on 2 : 1 ratio basis. Various doses of bisphenol A (0, 2, 20, 200, and 2,000 ${\mu}g kg^{-1}$) were daily administered to females for 21 days after parturition. Dams and offsprings were sacrificed at the time of weaning. The results were as fellows, 2000 ${\mu}g \; kg^{-1}$ / of bisphenol A decreased the dams' body weight at post-partum 18 days and also 200 and 2,000 ${\mu}g \;kg^{-1}$ of bisphenol A decreased the body weight of neonates at the days of post-partum 21 days. Bisphenol A increased the relative weights of liver and spleen in male offsprings, depending on the doses. But female offsprings showed high relative organ weights of ovaries, and low relative organ weights of uterine in a some dose-response manners. High dose of bisphenol A induced low viability of neonates exposed during lactation period. The dams treated with bisphenol A showed prematured estrous stage. Bisphenol A was recovered about 21.2% average in serum of dams, and also in offsprings'. The results indicate that the bisphenol A induces estrous cycle during lactation period in dams, also reaches to the offspring through breast milk. Thus bisphenol A exopsed to dams and neonates via lactation induces some estrogenic and tonic effects.

NADH Variation and Process Control with NADH Fluorometer in Full Scale Biological Nutrient Removal Process (실규모의 고도처리공정에서 NADH변화 유형과 이를 활용한 공정제어)

  • Kim, Han-Lae;Cho, Jong-Bok;Cho, Il-Hyoung;Lee, Jin-Woo;Chang, Soon-Woong;Lee, Si-Jin
    • Journal of Environmental Health Sciences
    • /
    • v.34 no.6
    • /
    • pp.423-432
    • /
    • 2008
  • In this study, we investigated the possibility of auto control and the proper operating factors in the BNR(Biological Nutrient Removal) process using an NADH(Reduced Nicotinamide Adenine Dinucleotide) fluorometer, which characterized the emitted fluorescence when activated by flashes of UV light at 460 nm. In terms of finding adequate operating parameters, results indicted that nitrification efficiency decreased in the controlled DO while denitrification efficiency decreased in the controlled pH. The above results indicated that controlled operating condition after combination with NADH, DO and pH was resonable. Result obtained from the correlation between NADH and pH showed that variation trend of influent loading was similar to those of NADH and pH, and also the variation cycle was repeated on a daily basis. Consequently, this result showed the increase of BOD loading caused the nitrification efficiency to decrease because air-flow, required for nitrification, was reduced, and so the NADH value was increased. From these results, it is possible to use NADH flourimetry to assess the variation of organic load and nitrification efficiency in the case of small change in influent pH such as in sewage and also to handle and operate the load variation in the auto control system using the NADH fluorometer.

A Sales Promotion Strategy for Casual Korean Traditional Clothes Using Database Marketing (데이터베이스 마케팅을 활용한 생활한복의 구매촉진 방안)

  • 임영미;이은경
    • Journal of the Korean Society of Costume
    • /
    • v.51 no.5
    • /
    • pp.29-43
    • /
    • 2001
  • Database marketing is a series of marketing activities based on the customer database for increasing the customer's life-time value. In this thesis. we applied database marketing to the sales promotional strategies of Casual Korean Traditional Clothes to activate wearing of Casual Korean Traditional Clothes. To achieve this goal, we surveyed the consciousness of wearing and purchases for Casual Korean Traditional Clothes. and extract information that can be utilized in the sales promotional strategies. According to the result, the proposed sales promotional strategies for Casual Korean Traditional Clothes are summarized as follows : (1) Useful information for the customer should be stored in the database and utilized in the marketing. (2) It is necessary to shorten the cycle of repeated purchases by emphasizing daily-life clothing of Casual Korean Traditional Clothes especially for the aged 20-40. (3) Since Casual Korean Traditional Clothes are usually weared as a ceremonial clothes in the fall, direct mail, fashion show, and advertising in the mass media should be concentrated on this season. (4) Value-added marketing should be derived by cross-selling of items harmonized with Casual Korean Traditional Clothes. (5) To guarantee fixed customers and increased usage of Casual Korean Traditional Clothes, - give point score, discount, or selling on an installment basis for the customers who use credit cards or department cards. - select privileged customers by analyzing purchase history and provide multiple services for these customers. - let the customers rent Casual Korean Traditional Clothes in an appropriate cost, and make customer cards for the construction of elaborated customer database. (6) To increase the acknowledgement of Casual Korean Traditional Clothes, not only Persistent publicity, but also fashion show, visual merchandising, and advertisement in mass media should be conducted as well.

  • PDF

Drastic Change of Phytoplankton Community at the Station 'Mankyeong Bridge' of the New Saemankeum Lake during 2006-2007 (2006-2007 기간 중 신생 새만금호 '만경대교' 정점에서 식물플랑크톤 군집 급변에 대한 연구)

  • Jang, Keon-Gang;Park, Jong-Woo;Park, Jang-Ho;Ha, Na;Yih, Won-Ho
    • Ocean and Polar Research
    • /
    • v.31 no.1
    • /
    • pp.71-76
    • /
    • 2009
  • Drastic changes in the water quality and phytoplankton community of the new Saemankeum Lakeduring the first decade following the construction of the Saemankeum Sea Wall has been considered to be unavoidable. Input of eutrophicated water through the Mankyeong River and Dongjin River might produce more direct effects on the water quality and phytoplankton community, which lead us to launch a long-term semi-weekly investigation at the "Mankyeong Bridge" monitoring point to resolve its short-term effect as well as long-term stabilization of the ecosystem in the new Saemankeum Lake. During 15 months starting from June 2006, the water temperature varied in accordance with the typical seasonal variations in temperate on the coasts, and no significant daily variations evoked by tidal cycle could be detected. However, there was an inverse relationship between seasonal precipitation and salinity even though the range in annual variation was drastically reduced right after the construction of the Saemankeum Sea Wall. Species richness in the phytoplankton community was also reduced due to the narrowed annual range of salinity, which would eliminate the mid-high salinity species from the Mankyeong Bridge monitoring point. Similarly, species diversity was decreased with increased dominance of the phytoplankton community after the construction. Between the two summer seasons during the present study, species diversity was higher in 2007 than in 2006, which might indicate the early stage of a gradual stabilization in the ecosystem including the phytoplankton community at the monitoring station. The phytoplankton community thus needs to be monitored on a long-term basis to identify indirect signals that can be used to assess the stability of the ecosystem in the young Saemankeum Lake.

Estimation of extreme sea levels at tide-dominated coastal zone (조석이 지배적인 해역의 극치해면 산정)

  • Kang, Ju Whan;Kim, Yang-Seon;Cho, Hongyeon;Shim, Jae-Seol
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.24 no.6
    • /
    • pp.381-389
    • /
    • 2012
  • An EST-based method which is applicable for estimating extreme sea levels from short sea-level records in a tide dominated coastal zone was developed. Via the method, annual maximum tidal level is chosen from the simulated 1-yr tidal data which are constituted by the independent daily high water levels, short term and long term surge heights and typhoon-induced surge heights. The high water levels are generated considering not only spring/neap tides and annual tide but also 18.6-year lunar nodal cycle. Typhoon-induced surges are selected from the training set which is constructed by observed or simulated surge heights. This yearly simulation is repeated many hundred years to yield the extreme tidal levels, and the whole process is carried out many hundred times repeatedly to get robust statistics of the levels. In addition, validation of the method is also shown by comparing the result with other researches with the tidal data of Mokpo Harbor.

A Study on Secondary School Students' Recognition on Weather Proverbs and Application to Science Teaching (일기속담에 대한 중.고등학생들의 인식과 과학수업에의 이용)

  • Kook, Dong-Sik;Lee, Cheol-Woo
    • Journal of the Korean Society of Earth Science Education
    • /
    • v.1 no.1
    • /
    • pp.85-98
    • /
    • 2008
  • Though the investigation of the suggested references proverbs related weather were collected and considered the probability of the usage on science instruction. The results are as follows. 130 proverbs related to weather were collected through the investigation of the suggested references. Most of weather proverbs are based on the states of sky, clouds, wind, precipitation, actions of animal, states of plants and the condition of people in daily life. they were classified according to weather types, natural phenomena and seasons. According to the results of analysing the students' recognition and interests on weather proverbs, most of students heard weather proverbs in their elementary school years firstly through their parents, books, and teachers. However they have only heard a few. Also many students also tend to think weather proverbs have a scientific base because weather proverbs have been told by many people through the ancient time and correspond to their personal experiences. Students responded that weather proverbs are useful for science learning on weather and can teach heritage and wisdom. After reading the suggested weather proverbs, their interests on weather proverbs were increased more than before reading. This is one of reasons why weather proverbs can be introduced to science classes. Weather proverbs were considered related to science curriculum. The third grade has a Unit "Fine days and Cloudy days", the fifth grade, "Unit of Weather Change", the Sixth grade, "Unit of Weather Forecast" , the Ninth grade, "Unit of Water cycle and Weather Change" and the tenth grade has "Unit of Earth". So the author consider that weather proverb materials can be used so effectively to bring about interest and motive in science learning.

  • PDF

The Seasonal Microbiological Quality Assessment of Kimbap(seaweed roll) Production flow in Foodservice facilities for Univ. students - HACCP model - (대학생 대상 급식시설의 김밥 생산과정에 따른 계절별 미생물적 품질평가)

  • 이혜상;류승연
    • Korean journal of food and cookery science
    • /
    • v.14 no.4
    • /
    • pp.367-374
    • /
    • 1998
  • The purpose of this study was to evaluate the microbiological quality of, and to assure the hygienic safety of, the kimbap production in the university foodservice facilities in accordance with the HACCP (Hazard Analysis Critical Control Point) Program. The time-temperature relationship and the microbiological quality (specifically, total plate count and coliform bacteria count) were assessed to find the critical control point (CCP) during each of the production phases. The average of the daily longest duration time of the kimbap at the facilities was 23.4 hours in summer, while 29.6 hours in winter. In the purchasing phase of the raw materials, the microbiological quality of laver, fish paste, carrot and cucumber in summer was not at an acceptable level according to the standard set by the Natick research center, especially the number of TPC and the coliform level of laver was higher than the threshold level. In the refrigerator storage phase, the temperature of the carrot was 7.4$^{\circ}C$. This temperature is far exceeding the standard so that the microbiological counts was increased by the 2 log cycle during the average storage time of 17 hours or more. In the preparation phase, the temperature of the blanching is too low compared to the standard. In the holding phase before serving, its time-temperature relationship was out of the FDA food code standard both in winter and summer. In the sewing phase, the number of microbiological count was higher than the threshold level in summer while that in winter was up to standard. According to the Harrigan and McCance standard, the number of microbiological count of the utensils was higher than the threshold level in summer while that in winter was up to standard.

  • PDF

Effects of Eurycoma longifolia Jack on Masculine Copulatory Behaviour in Middle Aged Male Rats - A Comparison Study

  • Ang, Hooi-Hoon;Lee, Kheng-Leng
    • Natural Product Sciences
    • /
    • v.8 no.2
    • /
    • pp.44-47
    • /
    • 2002
  • The effects of Eurycoma longifolia Jack on masculine copulatory behaviour were studied in the middle aged male Sprague-Dawley rats, 9 months old and retired breeders after dosing them with 500 mg/kg twice daily for 10 days prior to test. The test lasted for 30 minutes after a 20 minute adaptation period, was carried out on the 11th day during the dark phase of the light-dark cycle (2000-0700 hours) and in subdued light, using a modified copulation cage but with the presence of a piece of mirror of appropriate size to facilitate observation. Results showed that the mean values of EL-1, EL-2 and EL-3 of the control middle aged male rats were 103.20 sec, 91.21 sec and 80.00 sec but were significantly (p<0.05) increased to 118.40-120.20 sec, 101.24-171.28 sec and 100.42-110.21 sec respectively in the methanol-chloroform, methanol-butanol-water and methanol-butanol treated middle aged male rats. However, further results also showed that PEI-1 and PEI-2 of the control middle aged male rats were 182.30 sec and 257.2 sec but were significantly (p<0.05) decreased to 100.42-121.31 sec and 40.21-132.31 sec respectively in the methanol-chloroform-butanol-water and methanol-butanol treated middle aged male rats. In conclusion, this study showed that although E. longifolia Jack continued to enhance the sexual activity of the middle aged male rats by extending the duration of coitus and decreasing the refractory period between the different series of copulation, but to a smaller degree as compared to sexually active, adult male rats (Ang and Sim, 1997).

Highway Maintenance Cost Optimization Using GSIS (지형정보를 이용한 도로의 최적 유지관리 비용 산정)

  • 강인준;이준석
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.20 no.4
    • /
    • pp.367-374
    • /
    • 2002
  • Maintainability of highways is an important problem that is considered in the planning steps of a highway development process. A number of asset management systems have been developed to precisely predict maintenance and pavement expenditures for better decision making, But these systems are not helpful in reducing maintenance costs. Optimization of some highway design characteristics in the planning phases may reduce maintenance costs over the life cycle of highway. The formulations for initial and maintenance costs have been developed based on which design variables can be chosen to minimize these costs, focusing on the sideslope in cut and fill sections. Maintenance cost has been represented as a function of sideslope, width of highway cross section, and annual average daily traffic. A real geographic database of between Chung joo and Sang joo city in Choong buk was used and it is presented to investigate the sensitivities of maintenance cost and soil characteristics in selecting alignments. In this study, we present that maintenance cost and soil characteristics are important considerations in alignment optimization.