• 한국태양에너지학회 논문집
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• 제21권2호
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• pp.27-34
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• 2001

The greenhouse heating system using solar energy has been realized in the protective agriculture in this study in order to analyse the thermal energy characteristics of the system the effects of ambient air temperature, solar radiation, relative humidities and water content of ambient air on the greenhouse air temperature were investigated through computer simulation experimental analysis for validation of the simulation. The results from this study are summarized as follows: 1) The expected values of inside air temperature for the system solar energy were very much close to the experimental values. 2) In the system using solar energy, the expected values of daytime surface temperature of soil by computer simulation were very much similar to the measured values, but those of nighttime were higher than the measured value by almost $2.5^{\circ}C$. 3) Heat loss of daytime was found to be larger than that of night time as much as 2.0 to 4.2 times for the system using solar energy. 4) In the system using solar energy. while the ambient air temperature varied between $-7^{\circ}C$ and $-3.8^{\circ}C$, the temperature of the inside air was maintained between $0^{\circ}C$ and $22^{\circ}C$. 5) At the minimum ambient temperature of $-7^{\circ}C$, the temperature of the inside air was $0^{\circ}C$.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.58-59
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• 2006

Less than a decade ago, most alternate membrane materials for fuel cells relied upon a post-sulfonation process to generate ionic groups capable of transporting protons from the anode to the cathode. These random post sulfonations showed some promise, but in general they produced materials that were not sufficiently stable or protonically conductive at ion exchange capacities where aqueous swelling could be restricted. Our group began to synthesize disulfonated monomers that could be used to incorporate into random copolymer proton exchange membranes. The expected limitation was that the aromatic polymers might not be stable enough to withstand fuel cell conditions. However, this was mostly based upon an accelerated test known was the Fenton's Reagent Test, which did not seem to this author as being a reliable predictor of performance. A much better approach has been to evaluate the open circuit voltage (OCV) for alternate membranes, as well as the benchmark perfluorosulfonic acid systems. When this is done, the aromatic ionomers of this study, primarily based upon disulfonated polyarylene ether sulfones, show up quite well. Real time 3000 hours DMFC results have also been generated. Obtaining conductive materials at low humidities is another major issue where alternate membranes have not been particularly successful. In order to address this problem, multiblock copolymers with relatively high water diffusion coefficients have been designed, which show promise for conductivity at lowered humidity.

• 한국주거학회논문집
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• 제25권2호
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• pp.11-18
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• 2014

This study looked at designing, building and operating temporary camp, the first structures that South Korea built in the Antarctica. While there may be differences in accordance with the topography, ground surfaces in the Antarctica are covered broken stones, glaciers and snow. Hence, such topographical characteristics should be taken into account when conducting any construction work. To ensure successful assembly construction in the Antarctica using modules, prior trial assembly work should be done in Korea to identify any possible trouble in the actual construction process. Assuming that the workers will have to spend at least one winter in the temporary camp, the work will be more severely affected by adverse weather conditions and snow drift, resulting in the need to clear snow. This can be by designing roofs with curved surfaces. Also, quantitative effects will need to be verified through simulation and actual measurement. It will also be necessary to assess the camp's thermal environment and examine its air-conditioning methods. To identify the temporary camp's thermal system, the temperatures and humidities were measured, and the heating system was designed not to offer automatic control or desired value selection functions.

• 한국환경과학회지
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• 제19권2호
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• pp.125-136
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• 2010

The most important factors relating to the indoor air environment are temperature, airflow, humidity, and contaminant concentration. A sensitivity analysis of indoor environment factors was carried out to grasp influences along with changes of atmospheric conditions. An integrated multizone model was used to predict these sensitivities. This model was applied to an apartment with six zones. Airflow rates are influenced very seriously by changes of wind direct or wind velocity, but are influenced very slightly by changes of outdoor air temperature and are not influenced at all by changes of outdoor air humidity or contaminant concentration. Indoor air temperatures are influenced very directly by changes of outdoor air temperature, but are influenced very slightly by wind direction or wind velocity and are not influenced at all by changes of outdoor air humidity or contaminant concentration. Indoor air humidities are influenced very directly by changes of outdoor air humidity, but are not influenced at all by changes of outdoor air contaminant concentration and have little or no influence by changes of wind direction, wind velocity, or outdoor air temperature. Indoor air contaminant concentrations are influenced very seriously by changes of wind direct or wind velocity, but are influenced somewhat by changes of outdoor air contaminant concentration and are influenced very slightly by changes of outdoor air temperature and are not influenced at all by changes of outdoor air humidity.

• 생약학회지
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• 제19권3호
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• pp.201-207
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• 1988

Samples of red ginseng, which had been manufactured and packaged by the Korean Monopoly Corporation, were stored at ambient temperatures and humidities ($12{\sim}28^{\circ}$ and $55{\sim}68$ percent) for one to nine years to examine their overall quality stability. The proximate compositions, contents of 50% ethanol and water extracts of the samples and the TLC and HPLC patterns of ginsenosides in the samples remained almost unchanged in all cases. The lipids and fatty acids in the samples, which are otherwise susceptible to oxidation, were stable judged on the basis of the changes of the TLC and GLC patterns of the lipids and fatty acids. It was also found that polyunsaturated fatty acids such as linoleic(C18:2) and linolenic and(C18:3) present in the samples had been very stable during the long storage periods. It, therefore, seems that the autoxidations of the lipid and fatty acids of red ginseng were prevented by antioxidative compounds which will be progressively formed in red ginseng through non-enzymatic browning reactions during manufacturing process and long-term storage.

• The Plant Pathology Journal
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• 제15권3호
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• pp.144-151
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• 1999

Chitinase activities from Shumard oak tissues were determined to study changes in chitinase activities related to water stress. The enzyme extracted in sodium acetate buffer (0.1M, pH 4.5) was assayed by a colorimetric method. In addition, the fungal hyphae of Hypoxylon atropunctatum in xylem tissues of oak were observed through scanning electron microscopy. The enzyme in oak tissues was mainly endochitinase, and optimum pH for enzyme activity was 5. Specific chitinase activities from both of stems held under high relative humidity (ranges of 0.63-1.11 pKatal/$\mu\textrm{g}$ of protein) and stems held under low relative humidity (ranges of 0.41-0.99 pKatal/$\mu\textrm{g}$ of protein) were significantly increased following fungal inoculation with H. atropunctatum. However, there was no significant difference in chitinase activities between tissues held under high and low humidities, which might be due to fungal chitinase. Scanning electron microscopy showed holes in fungal hyphae in the xylem tissues of stems held under high humidity but not in the stems held under ow humidity, suggesting that hyphae might be hydrolyzed by plant hydolases such as chitinase.

• 한국대기환경학회지
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• 제10권4호
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• pp.260-280
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• 1994

The STEM II(Sulfur Transport Eulerian Model II) was adapted to simulate transport/ chemistry/deposition of air Pollutants in the Eastern China and Korea. A 32 hour model simulation starting from 9 A.M. of 1989 November 25 during which no preciptation was observed. The Prevailing wind direction is from west to east. The MM4(Meteorological Model Version 4) was used to generate meteorological data such as temperatures, horizontal wind velocities and directions, humidities, air densities. Eddy diffusivities, dry deposition velocities and vertical wind velocities were calculated from the meteorological data. The initial condition and the emission data base were constructed from the measurements and governmental reports respectively. The model predictions of NO, NO$_2$, SO$_2$, $O_3$ at Seoul, Inchon and Pusan agree reasonably well with measurements. The model's predictability for the primary air pollutants is improved considerably as the time passes. Thus, it is concluded that the model's predictability can be significantly enhanced by reducing the uncertainties of initial conditions.

• 한국대기환경학회지
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• 제22권2호
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• pp.191-199
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• 2006

Animal feedstuff handling is one of the major fugitive dust sources in the port of Incheon. For the effective control of fugitive dusts emitting from the port of Incheon, dust control facilities with bag filter systems should be designed properly considering the characteristic of the fugitive dusts including those from animal feedstuffs. The ultimate goal of this study is thus to develop the optimum fugitive dust control system which will be applicable for the renovation of the port. As the first step to achieve this longstanding goal, filtration characteristics of soybean shell, the largest dust sources in the port, were investigated with the specially designed filter testing apparatus for this study. The variables tested for the experiments included filter materials, dust concentrations, relative humidities, and filtration velocities. Also, the filtration characteristics of the other animal feedstuffs such as sunflower seed shell, tapioca, and palm shell were investigated to determine $K_2$ as a function of filtration velocity. The information on $K_2$ will be used to design the optimum bag filter systems for animal feedstuffs handling in the port.

• Journal of Advanced Marine Engineering and Technology
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• 제31권8호
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• pp.939-946
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• 2007

The purpose of this study is to measure and analyze the ship's indoor thermal conditions and also to integrate experimental database of those, supplied and controlled by ship's HVAC. On this study, temperature, humidity and air volume of 6 different needs' cabin are measured on a newly-launched training ship during 2nd through 5th of April, 2007. Followings are the results of this study. (1)Because only partial loads are needed in spring season, the air volume from diffusers are measured as below 20%. (2)The temperatures are ranged between $20{\sim}25^{\circ}C$ and those are within comfort temperature range proposed by AHREA. (3)But humidities in cabins are very low and it could be the reason of a cold and/or a skin disease. (4)From the student cabins' measurements which have different supply diffuser(s), it is clear that the design is suitable for this case. (5)Because of low humidity, only 16.1% among the measured data are satisfied with the comfort standard range proposed by ASHREA. To improve the predictability and the comfort, HVAC should maintain the humidity as $40{\sim}60%$.

• 펄프종이기술
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• 제47권6호
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• pp.5-21
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• 2015

The common production methods of nanocellulosic (cellulosic nanofibrils, CNF) materials from wood are being reviewed, together with large scale applications and particularly papermaking applications. The high energy demand for producing CNF has been one particular problem, which has been addressed over the years and can now be considered solved. Another problem was the clogging of homogenizers/microfluidizers, and the different routes to decrease the energy demand. The clogging tendency, related to the flocculation tendency of fibres is discussed in some detail. The most common methods to decrease the energy demand are TEMPO-oxidation, carboxymethylation and mechanical/enzymatic pre-treatments in the order of increased energy demand for delamination. The rheology characteristics of CNF materials, i.e. the high shear viscosity, shear thinning and the thixotropic properties are being illuminated. CNF materials are strength adjuvants that enhance the relative bonded area in paper sheets and, hence increase the sheet density and give an increased strength of the paper, particularly for chemical pulps. At the same time papers obtain a lower light scattering, higher hygroexpansion and decreased air permeability, similar to the effects of beating pulps. The negative effects on drainage by CNF materials must be alleviated through the appropriate use of microparticulate drainage aids. The use of CNF in films and coatings is interesting because CNF films and coatings can provide paper/board with good oxygen barrier properties, particularly at low relative humidities. Some other high volume applications such as concrete, oil recovery applications, automotive body applications and plastic packaging are also briefly discussed.