• Journal of Power System Engineering
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• v.12 no.4
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• pp.5-11
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• 2008

The RI gasoline engine haying a sub-chamber had a high cycle variation due to the difficulty of the residual gas scavenge in the sub-chamber. To solve this problem and improve the combustion performance of RI engine, we devised a method to inject directly CNG fuel into the sub-chamber. A DI diesel engine of single cylinder was converted into a RI-CNG engine and an electronic control unit for the engine was manufactured. In this study, the combustion characteristics of the RI-CNG engine were investigated with the injection timings and air excess ratios at the load conditions of 50% throttle open rate and 1700rpm. As the results from this study, the RI-CNG engine worked reliably under the condition of the ignitable lean limit of $\lambda=1.7$ by showing the $COV_{imep}$ below about 5%. And the highest thermal efficiency could be obtained in the injection timing that produced the high imep and the low $COV_{imep}$ at the same time. The CO emission concentration indicated very low values and the THC and $NO_x$ showed an opposite pattern. With a view to improving the thermal efficiency and reducing the harmful emissions, the proper control region of the ignition timing and the mixture ratio were nearly ATDC $20^{\circ}\sim50^{\circ}$ and $\lambda=1.4$ respectively.

• Journal of Radiation Protection and Research
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• v.9 no.2
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• pp.67-75
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• 1984

As a part of studies on acute effects of high dose irradiation the present report was carried out to evaluate the changes of the leukocyte life span in the Newzealand white male rabbits by a single whole body exposure to gamma rays from $^{60}Co$ teleirradiation unit. The exposure was done in dose levels of 100, 300, 550 and 1,000 rad to each experimental group of 10 rabbits. The life span and apparent half survival time of leukocytes, and the elution rate of leukocytes in the circulating blood were measured by McMillan method using $^{51}Cr$. 1. As a critical indicator of radiation hazards of the Newzealand male rabbits, the LD 50/30 and LD 100/30 after whole body exposure was estimated as 550 and 1,000 rads respectively. 2. The life span of leukocyte in the circulation after irradiation was slightly shortened in the 100 rad irradiated group, as compared with the unirradiated control group, but markedly shortened in the 300, 550 and 1,000 rads irradiated group. 3. After irradiation, decrease of leukocyte half survival time in the circulation showed the same pattern as that of leukocytes life span. 4. As the irradiation doses increased, the elution rate of $^{51}Cr$ loss from $^{51}Cr$ tagged leukocytes in the circulation were markedly increased gradually. 5. The life span shortening of leukocytes in the circulation after irradiation seems to occure by two processes of senescence acceleration and early destruction.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.12 no.4
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• pp.40-46
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• 2016

In order to improve air quality of indoor environment, studies of the underfloor air distribution (UFAD) system for application in buildings are actively in progress based on temperature and air flow distribution. However, although the age of air is the major evaluation parameter, there has been very little study on this parameter for the UFAD system. In this study, we investigated the age of air to reach the air diffuser, which is installed at the bottom of the interior by the UFAD system. Computational fluid dynamics simulations showed no regular pattern to the maximum value of the age of air in accordance with air flow rate and the velocity at air diffuser. These factors can be deduced from air movement by considering that air emitted from air conditioners was rotated according to the bottom shape of the floor, and then, the age of air in the rotation center was increased. The average age of air of internal interior was reduced considerably as the flow velocity at the underfloor air diffuser was increased from 0.5 m/s to 1.0 m/s However, the age of air was not substantially affected with change in the air volume. Moreover, when the flow velocity at the underfloor air diffuser was higher than 1.0 m/s, the age of air showed no significant difference with change in air volume or height of measurement. These results imply that indoor air quality is more substantially influenced by flow velocity than air volume, and the appropriate flow velocity is 1 m/s or more.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.9
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• pp.1363-1370
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• 2016

Rennet, a complex of enzymes found in the stomachs of ruminants, is an important component for cheese production. In our study, we described that yak chymosin gene recombinant Pichia pastoris strain could serve as a novel source for rennet production. Yaks total RNA was extracted from the abomasum of an unweaned yak. The yak preprochymosin, prochymosin, and chymosin genes from total RNA were isolated using gene specific primers based on cattle chymosin gene sequence respectively and analyzed their expression pattern byreal time-polymerase chain reaction. The result showed that the chymosin gene expression level of the sucking yaks was 11.45 times higher than one of adult yaks and yak chymosin belongs to Bovidae family in phylogenetic analysis. To express each, the preprochymosin, prochymosin, and chymosin genes were ligated into the expression vector $pPICZ{\alpha}A$, respectively, and were expressed in Pichia pastoris X33. The results showed that all the recombinant clones of P. pastoris containing the preprochymosin, prochymosin or chymosin genes could produce the active form of recombinant chymosin into the culture supernatant. Heterologous expressed prochymosin (14.55 Soxhlet unit/mL) had the highest enzyme activity of the three expressed chymosin enzymes. Therefore, we suggest that the yak chymosin gene recombinant Pichia pastoris strain could provide an alternative source of rennet production.

• Korean Journal of Adult Nursing
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• v.18 no.4
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• pp.543-552
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• 2006

Purpose: The purpose of this descriptive study was to investigate the pattern of physical restraints used in ICUs and to identify influencing factors of application and removal of restraints. Method: The subjects of this study were 90 restrained patients out of 215 patients over 6 years old who were admitted to 6 ICUs in SMC during a 2 weeks period. The data was collected through a questionnaire of characteristics, guidelines and nursing care of restraint uses. The data were analyzed by non-parametric statistic with the use of the SAS program. Results: The restraints were applied to 31.4% of subjects. Mean time of physical restraint was $36.76{\pm}55.7$ hours. There were significant difference with mean time and frequency according to duty shift. GCS, restless behavior and discomfort factors, medical devices, and life sustaining devices had significant relation with application of restraints. In addition, the mean time of restraints used were related significantly with GCS, restless behavior, and discomfort factors. Conclusion: The used of restraints were dependent on mainly the nurses' decision. Thus ICU nurses have to develop the guidelines to applying restraints and removal of restraints in regard to patients rights and ethics. Continuous monitoring and evaluation of application of the restraints is essential in professional nursing.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.13
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• pp.5311-5317
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• 2015

Cigarette smoke derivatives like NNK (4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone) and NNAL (4-(methylnitrosamino)-1-(3-pyridyl)-1-butan-1-ol) are well-known carcinogens. We analyzed the interaction of enzymes involved in the NER (nucleotide excision repair) pathway with ligands (NNK and NNAL). Binding was characterized for the enzymes sharing equivalent or better interaction as compared to +Ve control. The highest obtained docking energy between NNK and enzymes RAD23A, CCNH, CDK7, and CETN2 were -7.13 kcal/mol, -7.27 kcal/mol, -8.05 kcal/mol and -7.58 kcal/mol respectively. Similarly the highest obtained docking energy between NNAL and enzymes RAD23A, CCNH, CDK7, and CETN2 were -7.46 kcal/mol, -7.94 kcal/mol, -7.83 kcal/mol and -7.67 kcal/mol respectively. In order to find out the effect of NNK and NNAL on enzymes involved in the NER pathway applying protein-protein interaction and protein-complex (i.e. enzymes docked with NNK/NNAL) interaction analysis. It was found that carcinogens are well capable to reduce the normal functioning of genes like RAD23A (HR23A), CCNH, CDK7 and CETN2. In silico analysis indicated loss of functions of these genes and their corresponding enzymes, which possibly might be a cause for alteration of DNA repair pathways leading to damage buildup and finally contributing to cancer formation.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.4
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• pp.73-80
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• 2004

A dual purpose robot automation system is developed for both arc welding and spot welding by one robot within a cell. The need for automation of both arc welding and spot welding processes is urgent while the production volume is not so big as to accommodate separate station for the two processes. Also, space is too narrow for separate station to be settled down in the factory. A spot welding robot is chosen and the function for arc welding are implemented in-house at cost of advanced functions. For the spot welding, a single pole type gun is used and the robot has to push down the plate to be welded, which causes the robot positioning error. Therefore, position error compensation algorithm is developed. The basic functions for the arc welding processes are implemented using the digital I/O board of robot controller, PLC, and A/D conversion PCB. The weaving pattern is taught in meticulously by manual teach. A fixture unit is also developed for dual purpose. The main aspects of the system is presented in this paper especially in the design and implementation procedure. The signal diagrams and sequence logic diagrams are also included. The outcome of the dual purpose welding cell is the increased productivity and good production stability which is indispensable for production volume prediction. Also, it leads to reduction of manufacturing lead time.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.8
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• pp.1078-1084
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• 2001

Twelve growing male lambs ($10.05{\pm}0.41kg$, 5 months age) were assigned to three equal groups in a completely randomized design and fed respectively wheat straw (WS), ammoniated wheat straw (AWS) or urea supplemented wheat straw (USWS) along with concentrate mixtures of varying protein and energy contents to meet their requirements as per NRC (1985). Despite comparable nutrient intake and digestibility, the lambs fed A WS based diet digested lower (p<0.05) crude protein. The digestibility of NDF and hemicellulose were lower while the digestibility of cellulose was higher in lambs on AWS as compared to lambs on USWS based diet. The lambs of all the three groups were in positive and comparable N, Ca and P balance except higher Ca balance in lambs fed WS based diet. The body weight change, average daily gain and feed conversion efficiency were similar among the dietary groups. All the parameters of rumen fermentation pattern were comparable between lambs of AWS and USWS based diets except ammonia-N concentration that was higher in the latter however it was lower in WS fed group. Though, the feeding cost per unit gain was comparable in lambs fed all the three diets, the cost incurred towards roughage during 120 days of experimental feeding was significantly less in lambs fed AWS than UTWS. Thus, feeding of USWS can be practiced to minimize labour cost and environmental pollution involved in the process of urea treatment without affecting the performance of growing lambs.

• Journal of Korean Society for Geospatial Information Science
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• v.12 no.3 s.30
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• pp.13-21
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• 2004

Landuse information is used to plan land use, urban and environmental management as base data. And, demand for landuse information is rising due to ecological consideration. But existing method to extract landuse information from aerial photographs or field survey is consume a lot of time and cost. In urban area where the pattern of landuse is densely aggregated, a landuse information needs to be classified in detail for urban planning and management. Therefore this study aims to examine the method to extract landuse information in detail from 1:1,000 digital topographic data. For the purpose, the method was applied to a part of metropolitan Seoul. The results of study shows that extraction of landuse information except forest area is possible. Forest area is needed to describe smaller spatial unit. For the future, the method of describing forest area is improved it will be effectively applicable for the city maintenance.

• Journal of Microbiology and Biotechnology
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• v.9 no.6
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• pp.847-853
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• 1999

A Pseudomonas sp. strain that is capable of utilizing dicarboxylic acids as a sole carbon source was isolated from activated sludge by using the enrichment culture technique. This organism accumulated polyhydroxyalkanoates (PHAs) with an unusual pattern of monomer units that depends on the carbon sources used. Polyhydroxybutyrate (PHB) homopolyester was synthesized from glucose or small $C_{-even}$ alkanoic acids, such as butyric acid and hexanoic acid. Accumulation of PHB homopolyester was also observed in the cells grown on $C_{-odd}$ dicarboxylic acids, such as heptanedioic acid and nonanedioic acid as the sole carbon sources. In contrast, a copolyester consisting of 6 mol% 3-hydroxybutyrate (3HB) and 94 mol% 3-hydroxyvalerate (3HV) was produced with a PHA content of as much as 36% of the cellular dry matter. This strain produced PHAs consisting both of the short-chain-length (SCL) and the medium-chain-length (MCL) 3-hydroxyacid units when heptanoic acid to undecanoic acid were fed as the sole carbon sources. Most interestingly, polyester consisting of significant amount of relevant fractions, 3HB, 3HV, and 3-hydroxyheptanoate (3HHp), was accumulated from heptanoic acid. According to solvent fractionation experiments, the polymer produced from heptanoic acid was a blend of poly(3HHp) and of a copolyester of 3HB, 3HV, and 3HHp units. The hexane soluble fractions contained only 3HHp units while the hexane-insoluble fractions contained 3HB and 3HV units with a small amount of 3HHp unit. The copolyester was an elastomer with unusual mechanical properties. The maximum elongation ratio of the copolyester was 460% with an ultimate strength of 10 MPa, which was very different from those of poly(3HB-co-3HV) copolyesters having similar compositions produced from other microorganisms.