• Applied Chemistry for Engineering
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• v.21 no.4
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• pp.385-390
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• 2010

Transesterifications of vegetable oils (soybean oil, grapeseed oil, corn oil, canola oil) by ultrasonic energy were examined on various catalysts for biodiesel production. Reaction activities of the transesterifications were evaluated to the ultrasonic energy and thermal energy. The physicochemical properties and product distribution were also investigated to the biodiesels produced from the oils in the reaction using ultrasonic energy. The yields of fatty acid methyl ester (FAME) on the alkali catalysts were higher than those on the acid catalysts. The highest FAME yield was obtained as 83% on potassium hydroxide catalyst in the transesterification. The effective reaction conditions by ultrasonic energy were 1 wt% catalyst loading and 6:1 molar ratio of methanol to vegetable oils. The reaction rate of the transesterification by ultrasonic energy was faster than that by thermal energy. The acid values of the biodiesel products were improved above 30% compared to those of the feedstocks.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.3
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• pp.289-294
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• 2011

In this study, the seismic analysis of traveling sea water screen for nuclear power plant was performed using finite element model. For qualification of traveling sea water screen, the response spectrum analysis was performed using the given operating basis earthquake(OBE) and safe shutdown earthquake(SSE) floor response spectrum. Dynamic analysis of water sea traveling screen was performed using finite element method. The analytical maximum displacements of traveling sea water screen were 2.5 mm under OBE condition and 4.6 mm under SSE condition. The maximum stresses of traveling sea water screen were 24 MPa under OBE condition and 44 MPa under SSE condition, that this results were 18 %, 27% of yield strength of material. Thus, it can shown that the structural integrity of traveling sea water screen has a stable structure for seismic load conditions.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.48 no.1
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• pp.82-90
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• 2012

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.

• Journal of Environmental Science International
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• v.22 no.11
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• pp.1457-1464
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• 2013

We investigated the optimal conditions for keratinase production by feather-degrading Pseudomonas geniculata H10 using one variable at a time (OVT) method. The optimal medium composition and cultural condition for keratinase production were determined to be glucose 0.15% (w/v), beef extract 0.08% (w/v), $KH_2PO_4$ 0.12% (w/v), $K_2HPO_4$ 0.02% (w/v), NaCl 0.07% (w/v), $MgSO_4{\cdot}7H_2O$ 0.03%, $MgCl_2{\cdot}6H_2O$ 0.04% along with initial pH 10 at 200 rpm and $25^{\circ}C$, respectively. The production yield of keratinase was 31.6 U/ml in an optimal condition, showing 4.6-fold higher than that in basal medium. The strain H10 also showed plant growth promoting activities. This strain had ammonification activity and produced indoleacetic acid (IAA), siderophore and a variety of hydrolytic enzymes such as protease, lipase and chitinase. Therefore, this study showed that P. geniculata H10 could be not only used to upgrade the nutritional value of feather wastes but also useful in situ biodegradation of feather wastes. Moreover, it is also a potential candidate for the development of biofertilizing agent applicable to crop plant soil.

• Korean journal of applied entomology
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• v.15 no.4 s.29
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• pp.185-191
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• 1976

This study was conducted to evaluate the performance of 2,4-D amine salt (2,4-dichlorophenoxy acetic acid) 40EC in broadleaf weeds control under diverse conditions of rate and time of application and soil type in fall barley field. The results obtained were summarized as follows: 1) At the rate of 70cc prod./10a, 2,4-D amine salt treated during the fully tillered stage of barley was effective for the control of most broadleaf weeds without crop injury. 2) The fully tillered stage was a optimun time lot the application of 2,4-D amine salt in fall barley. Earlier(zero-to four-leaf stage) or late. (boot stage to flowering) application than this stage caused a crop injury and resulted in yield reduction. 3) It was possible to safely use 2,4-D amine salt in fall barley regardless of soil types if applied the rate of 70cc prod./10a at the fully tillered stage.

• Journal of the Korean Chemical Society
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• v.31 no.2
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• pp.197-202
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• 1987

Sigmatropic rearrangement of cis and trans-2-methyl-N-phenyl-1,3-oxathiolane-2-acetamide (b) and (c) gave unisolable sulfenic acids (d) and (f), respectively. These sulfenic acids were confirmed by deuterium exchange reactions involving 2-methylene and 2-methyl groups. The reactions also showed that no isomerization between the cis and trans sulfoxides (b) and (c) occurred under neutral conditions. However, the isomerization took place in the presence of acid catalyst. Stereospecific recyclization of sulfenic acids to the sulfoxides is attributable to possible hydrogen bonding between sulfenyl oxygen and NH proton or it arises from the geometrical requirements of the reacting bond and atoms in the reverse sigmatropic rearrangement. In the oxidation of 1, 3-oxathiolane, cis sulfoxide (b) could be obtained selectively in high yield by using $H_2O_2$-benzene seleninic acid.

• Journal of the Korean Chemical Society
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• v.29 no.4
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• pp.441-447
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• 1985

Several benzanilides were prepared by acylation of anilines with substituted benzoyl chlorides. While 2-chlorobenzanilides were photocyclized, 2-methylbenzanilide and 2'-methylbenzanilide were cleaved to give photo-Fries type products. 2-Nitrobenzanilide and 2'-nitrobenzanilide were inert in the above conditions due to lowering energy of the excited state by the nitro group. N, N-dibenzoylaniline and N, N-di-(2-chlorobenzoyl) aniline gave photo-Fries type reaction products effectively. In the benzanilide photo-Fries type reaction the excited singlet state was believed to be involved, since no oxygen effect was observed on the reaction rate. Quantum yield for 2-methylbenzanilide is higher in nonpolar and less viscous solvents than in polar and viscous solvents. The solvent cage radical pair is suggested in the photo-Fries type reaction of benzanilides.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.2
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• pp.91-106
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• 2013

Exserohilum turcicum is considered serious destructive disease of maize (Zea mays L.) in North Korea. This study aimed to understand genetic inheritance and combining ability of newly bred lines of maize tolerant to E. turcicum by diallel crosses. Three diallel sets for two different ecological regions and one agronomic trait; eastern (E), northern (N) and stay green (SG) involving 29 inbred lines were tested in eight locations of 2000 and 2001. E. turcicum infections were under natural conditions, respectively. Lines used were selected for high yield potential in test crosses with good agronomic traits and tolerance to biotic and abiotic stresses. Selection for race specific high resistance to biotic stresses was avoided to select quantitatively inherited genes. Host plant responses to E. turcicum were rated on a scale of 1 (highly tolerant) to 9 (highly susceptible). Highly significant variations were recorded in all trials. General combining ability (GCA) mean square was roughly twice that of specific combining ability (SCA). The genotype (G) by environment (E) interaction was highly significant. The overall results of genetic studies in three diallel sets show that genetic control for inbred tolerance to E. turcicum is polygenic and quantitatively inherited. New inbreds; E-3, N-1 and SG-4 confer better tolerance to E. turcicum than the widely used inbreds; Mo17, and B73. Proper use of genetic information from this study shall increase of corn production under high E. turcicum infection in the Far Eastern Regions of Korea and China.

• New & Renewable Energy
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• v.16 no.3
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• pp.1-12
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• 2020

Shingled technology is the latest cell interconnection technology developed in the photovoltaic (PV) industry due to its reduced resistance loss, low-cost, and innovative electrically conductive adhesive (ECA). There are several advantages associated with shingled technology to develop cell to module (CTM) such as the module area enlargement, low processing temperature, and interconnection; these advantages further improves the energy yield capacity. This review paper provides valuable insight into CTM loss when cells are interconnected by shingled technology to form modules. The fill factor (FF) had improved, further reducing electrical power loss compared to the conventional module interconnection technology. The commercial PV module technology was mainly focused on different performance parameters; the module maximum power point (Pmpp), and module efficiency. The module was then subjected to anti-reflection (AR) coating and encapsulant material to absorb infrared (IR) and ultraviolet (UV) light, which can increase the overall efficiency of the shingled module by up to 24.4%. Module fabrication by shingled interconnection technology uses EGaIn paste; this enables further increases in output power under standard test conditions. Previous research has demonstrated that a total module output power of approximately 400 Wp may be achieved using shingled technology and CTM loss may be reduced to 0.03%, alongside the low cost of fabrication.

• Korean Journal of Remote Sensing
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• v.33 no.5_2
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• pp.751-762
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• 2017

A crop information system can provide information regarding crop distribution, crop growth conditions, crop yield in various forms such as monitoring, forecasting, estimation or analysis. This paper presents the design and construction of a crop information system based on data collected in Korea, USA, and China. Therein, climate data including temperature, precipitation,solar radiation are used to evaluate the impact on crop growth, NDVI (Normalized Difference Vegetation Index) data is used in crop monitoring, and crop map data is utilized for the management of crop distribution. The system has achieved three prominent results: 1) Providing information with high frequency, 2) Automatically creating the report through the analysis of the data, 3) The users to easily approach the system and retrieve the information.