• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.2
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• pp.52-62
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• 1974

The fresh water prawn, Macrobrachium rosenbergi (De Maan) is a very common species in Info-pacific region inhabiting both fresh and brackish waters in low land areas, and especially abundant in the lower reaches of most rivers which are influenced by seawater, It is one of the largest and commercial species of genus Macrobrachium. As a place of the researches to clear the possibilities of transplantation and propagation of this species in the Far East region the larval development, growth, optimum temperature and metamorphose rate up to first post larvae in aquaruim are cleared under the conditions of salinity $6.58-7.05\%_{\circ}$ Cl, pH 8.0-8.2, the rate of flow 0.3 liter per minute and illumination 3000 lux. Temperature ranged from 27.5 to $28.7^{\circ}C$ during the period of earlier larval development. For the study oil the relationship between temperature and metamorphose rate from zoea to first post larvae, the temperatures in experimental tank were $22.2^{\circ}C\pm1$, $26.1^{\circ}C\pm0.85$, $28.1^{\circ}C\pm0.34$, $30.4^{\circ}C\pm0.66$, $33.7^{\circ}C\pm0.66$, $33.7^{\circ}C\pm0.38$ and $36.8^{\circ}C\pm0.26$. During the work, food used for the larvae was Artemia salina nauplius in the filter-circulation aquariums. This species metamorphosed to the first post-larvae through eleven zoea stages, and the characters of each larval stage are described and optimum temperature for metamorphosis rate and survivals to the first post larvae is $28.1^{\circ}C\pm0.34$.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.4
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• pp.263-273
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• 2016

The effect of recirculated exhaust gas on performance and exhaust emissions with FGR rate are investigated by using a natural circulation, pressurized draft and water tube boiler with FGR system operating at several boiler loads and over fire air damper openings. The purpose of this study is to apply the FGR system to a power plant boiler for reducing $NO_x$ emissions. To activate the combustion, the OFA with 0 to 20% is supplied into the flame. When the suction damper of two stage combustion system installed in the upper side of wind box is opened by handling the lever between $0^{\circ}$ and $90^{\circ}$, also, the combustion air supplied to burner is changed. It is found that the fuel consumption rate per evaporation rate did not show an obvious tendency to increase or decrease with rising the FGR rate, and $NO_x$ emissions at the same OFA damper opening are decreased, as FGR rates are elevated and boiler loads are dropped. While a trace amount of soot is emitted without regard to the operation conditions of boiler load, OFA damper opening and FGR rate, because soot emissions are eliminated by the electrostatic precipitator with a collecting efficiency of 86.7%.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.12
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• pp.1367-1373
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• 2011

This research concerns the development of a compression/absorption high-temperature hybrid heat pump that uses a natural refrigerant mixture. Heat pumps based on the compression/absorption cycle offer various advantages over conventional heat pumps based on the vapor compression cycle, such as large temperature glide, temperature lift, flexible operating range, and capacity control. In this study, a lab-scale prototype hybrid heat pump was constructed with a two-stage compressor, absorber, desorber, desuperheater, solution heat exchanger, solution pump, liquid/vapor separator, and rectifier as the main components. The hybrid heat pump system operated at 10-kW-class heating capacity producing hot water whose temperature was more than $90^{\circ}C$ when the heat source and sink temperatures were $50^{\circ}C$. Experiments with various $NH_3/H_2O$ mass fractions and compressor/pump circulation ratios were performed on the system. From the study, the system performance was optimized at a specific $NH_3$ concentration.

• Journal of the Korea Institute of Building Construction
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• v.17 no.5
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• pp.453-463
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• 2017

Due to the increase in the size of buildings and scale, the importance of construction engineering that reflects the constructability from the design stage of the project is increasing. Especially, engineering efforts related to facilities, equipment and construction methods for temporary work at the design stage can significantly contribute to improvement of constructability and project performance. The purpose of this study is to derive construction engineering tasks on temporary work at the design phase of the high-rise building projects. 27 preliminary tasks were firstly investigated through literature review and experts' group interview, and the necessity and importance analysis of each tasks were then performed based on questionnaire survey. Most of the tasks related to plans on structural framework and lifting equipment were analyzed as relatively more important ones. Lastly, 21 engineering tasks, which are classified into 5 factors, were proposed through factor analysis. The factors were determined as 1) structural framework, measurement and circulation, 2) lifting equipment and pumping, 3) space zoning, 4) water supply, 5) temporary facility, electric power supply and lighting. The results of this study can be used as basic data for establishing efficient work process of construction engineering on temporary work at the design phase.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.2
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• pp.357-364
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• 2008

Mylabris is the dried body of the chinese blister beetle. The species used in medicine are Mylabris phalerata and M. cichorii. In recent studies, it has been found that Mylabris possesses antitumor properties, increases the number of leukocytes, and has irritant effects on the urinary organs. The crude extracts of Mylabris have been noted for their highly irritant action and other traditional uses of Mylabris include treatment of poor local blood circulation. The active constituent of Mylabris is cantharidin. The chemical is notable for its vesicant properties, but with severe side effects such as nephrotoxicity. This experiment examined the effect of extracts and fractions, obtained from Mylabris phalerata Pall. on hair growth activity of the C57BL/6N mice after topical application to skin. First, we examined the effect of an extracts, obtained from the alcohol extracts of dried Mylabris phalerata Pall. on hair growth activity of the C57BL/6N mice after topical application to skin. Second, we examined on hair growth activity of the cantharidin fraction of Mylabris phalerata Pall. compared to the control and 1% minoxidil groups. Third, we investigated the number of hair follicle and mast cells after topical application of extracts of Mylabris phalerata Pall. to skin for 16 days. The results were as follows: Hair growth effect from the extracts of Mylabris phalerata Pall.(0.312%) was observed in 80% of mice whose hair had been removed in 13 days. Hair growth effect from the extract of Mylabris phalerata Pall.(0.312 and 0.625%) and 1% minoxidil group was observed in 100% of mice whose hair had been clipped in 20 days. Hair growth effect from the cantharidin fraction(0.5%) and water fraction(0.5%) of Mylabris phalerata Pall. was observed in 100% of mice whose hair had been clipped in 24 days. The hair growth effect on the cantharidin fraction(0.125%) was observed to be strong compared with the minoxidil(3%) group, commercial hair growth agents, in mice whose hair had been clipped in 19 days. In the spontaneous alopecia mice model, the hair growth effect from the cantharidin fraction (0.125%) was observed to be strong as compared with the states before the 13 days experiment. These experiments suggest that extracts and fractions of Mylabris phalerata Pall. may stimulate the topical hair growth activity in low doses.

• Journal of Wetlands Research
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• v.14 no.2
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• pp.265-275
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• 2012

As climate change is becoming a growing concern and the importance of water management is increasing, the retention of carbon and nutrients in wetland soils including inland and coastal area has become important. In this study, retention characteristics of organic matter and nutrients of coastal sediment and soils in different types of wetlands such as constructed wetland, natural (inland marsh, estuary, tidal flat) wetlands were investigated. A correlation analysis was also performed to understand the relationship among organic matter properties, nutrient concentrations and soil texture of wetland soils. The degree of retention of organic matter and nitrogen in wetland soils varied with the wetland type. Inland wetlands retain more nitrogen than estuary or coastal wetlands, and natural wetlands retain more organic matter and nitrogen than constructed ones. Coastal sediments in a bay area where seawater circulation is restricted have more nutrients than those in estuary or tidal flats where seawater circulates well. The results showed that the sediment chemical oxygen demand has a high correlation with the total organic carbon and the total nitrogen in the studied area.

• Economic and Environmental Geology
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• v.48 no.5
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• pp.371-377
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• 2015

Isotopic compositions of precipitation have been used to understand moisture transport in the atmosphere and interactions between precipitation and groundwater. Isotopic compositions of speleothems and ice cores, so called, ''paleoarchives'', can be utilized to interpret climate of the past and global circulation models (GCMs). The GCMs are able to explain the paleoarchives, can be validated by the precipitation isotopes. The developments of stable isotope analyzers make high-resolution isotopic studies feasible. Therefore, a high-resolution study of precipitation isotopes is needed. For this study, precipitation samples were collected for every 5 to 15 minutes, depending on precipitation rates, using an auto-sampler for precipitation isotopes near coastal area. The isotopic compositions of precipitation range from -5.7‰ (-40.1‰) to -10.8‰ (-74.3‰) for oxygen (hydrogen). The slope of ${\delta}^{18}O-{\delta}D$ diagram for the whole period is 6.8, but that of each storm is 5.1, 4.2, 7.9 and 7.7, respectively. It indicates that evaporation occurred during the first two storms, while the latter two storm did not experience any evaporation. The isotopic fractionations of precipitation has significant implications for the water cycle and high-resolution data of precipitation isotopes will be needed for the future studies.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.4
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• pp.604-610
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• 2005

This study was to evaluate the effects of several light curing units on the microleakage of composite resin restorations in primary teeth. The types of curing units were traditional low intensity halogen light(Optilux 360), plasma arc light(Filpo) low heat plasma arc light(Aurys) and high intensity LED(Freelight 2). After preparing cavities on sound primary teeth, cavities were filled with composite resin(Z100) using the same resin bond agent(Scotchbond Multi-Purpose) and were cured with each curing light system. After storing each specimen in sterile water for 24 hours, thermal circulation was done 1,000 times followed by pigmentation using 2% methylene blue solution. Each specimen was sliced and the degree of pigmentation was graded. When microleakage is graded, the average of Aurys was 0.95 which was the lowest and Freelight 2(1.05), Filpo(1.25), Optilux 360(1.30) followed. But values were not shown statistically significant difference (P>0.05). The results suggest that the newly developed curing units which has advantage in children by decreasing discomfort and procedure time can increase the microleakage of the composite resin.

• Journal of Plant Biology
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• v.16 no.3_4
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• pp.17-34
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• 1973

The physico-chemical factors, the distribution of chlorophyll and the primary production of the lakes Hwajinpo, Yongrangho, Chunchonho, Uiamho, Soyangho and Changjamot have been studied in order to make ecological comparison among these lakes during summer stagnation period of August to September of 1973. On the basis of the characteristics of these lakes, the lake types have been discussed. Thermocline is observed at 3-4m zone in the lake Changjamot and 4-5m zone in the lake Yongrangho. In the case of lake Hwajinpo and impoundments, the distinct thermal stratification is not observed at the summer stagnation period. As to vertical distribution of dissolved oxygen, a positive heterograde curve is obtained in the lakes Hwajinpo and Yongrangho. In the lake Changjamot the typical clinograde curve and the oxygen depletion in hypolimnion are observed. In the case of impoundments, however, the orthograde curve is observed in the lakes Chunchonho and Uiamho. While in the lake Soyangho, any stratification of the disssolved oxygen is not found. In the brackish lakes, such as lakes Hwajinpo and Yongragho, the salinity of hypolimnion is found to be much higher than that of epilimnion. In the lake Hwajinpo, the salinity of hypolimnion is exhibited 32.7$\textperthousand$, which is nearly the same as sea water. The distribution of nitrogenous compounds and phosphates is found to be high in the lake Changjmot. The silicate is also found in high concentration in the lake Chunchonho, and the distribution of nutrients in the brackish lakes is generally low. As to the vertical distribution of chlorophyll level, the lake Changjamot shows a stratum type and the brackish lakes L-type stratification. In the impoundments, lakes Chunchonho and Uiamho appear to be homogeneous type. Seasonal variation of chlorophyll level in the lake Changjamot is examined from January to September 1973. The vertical distribution of chlorophyll during the period of circulation from January to April is homogeneous type and is stratum type thereafter. The maximum chlorophyll level is 277.4mg/$m^2$ on June 23 and the pattern of seasonal variation of chlorophyll level is comparable to the type of eutrophy. The horizontal distribution of chlorophyll level is studied in the brackish lakes, Hwajinpo and Yongrangho. The pattern of distribution is found to be an irregular type. On the basis of measurements of primary production by means of the carbon-14 method and the distribution of chlorophyll level, it is concluded that the interior part of the lake Hwajinpo and Changjamot are eutrophic and the exterior part of the lake Hwajinpo, lake Yongrangho and the impoundments, lake Uiambo and Soyangho are mesotrophic.

• Journal of Wetlands Research
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• v.22 no.4
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• pp.312-320
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• 2020

Various LIDs with natural water circulation function are applied to reduce urban environmental problems and environmental impact of development projects. However, excessive Infiltration and evaporation of LID facilities dry the LID internal soil, thus reducing plant and microbial activity and reducing environmental re duction ability. The purpose of this study was to develop a real-time measurement system with complex sensors to derive the management plan of LID facilities. The test of measurable sensors and Internet of Things (IoT) application was conducted in artificial wetlands shaped in acrylic boxes. The applied sensors were intended to be built at a low cost considering the distributed LID and were based on Arduino and Raspberry Pi, which are relatively inexpensive and commercialized. In addition, the goal was to develop complex sensor measurements to analyze the current state o f LID facilities and the effects of maintenance and abnormal weather conditions. Sensors are required to measure wind direction, wind speed, rainfall, carbon dioxide, Micro-dust, temperature and humidity, acidity, and location information in real time. Data collection devices, storage server programs, and operation programs for PC and mobile devices were developed to collect, transmit and check the results of measured data from applied sensors. The measurements obtained through each sensor are passed through the Wifi module to the management server and stored on the database server in real time. Analysis of the four-month measurement result values conducted in this study confirmed the stability and applicability of ICT technology application to LID facilities. Real-time measured values are found to be able to utilize big data to evaluate the functions of LID facilities and derive maintenance measures.