• Solar Energy
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• v.19 no.3
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• pp.101-113
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• 1999

Thermodynamic performance of a simple Rankine cycle, regenerative Rankine cycle, and Kalina cycle for Ocean thermal Energy Conversion(OTEC) is evaluated under the same condition with various working fluids. The evaporator and condenser are modeled by a UA and LMTD method while the turbine and pump are modeled by considering isentropic efficiencies. As for the working fluids, R22, R134a, R32, propylene, ammonia are used for the Rankine cycles while ammonia/water and R32/R134a mixtures are used for Kalina cycle. Calculated results show that newly developed fluids such non-ozone depleting refrigerants as R134a and R32 perform as well as R22 and ammonia. The regenerative Rankine cycle showed a 1.2 to 2.8% increase in energy efficiency as compared to the simple Rankine cycle while the Kalina cycle with ammonia/water mixture showed a 1.8% increase in energy efficiency. The efficiency of the Kalina cycle with R32/R134a mixtures is the same as that of a simple Rankine cycle using R22. Therefore, the regenerative Rankine cycle turns out to be best choice for OTEC applications.

• Toxicological Research
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• v.28 no.2
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• pp.113-116
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• 2012

Various kinds of positive effects of green tea extracts had been studied for long time which included anti-inflammation, anti-aging, and cardiometabolic effects. Although topical steroid and non-steroidal calcineurin inhibitors may control clinical symptoms of allergic contact dermatitis, some of patients also present allergic reaction to these topical agents. Therefore, we have tried green tea extracts for managing this skin disorder with expectation of anti-inflammatory effect without potential side effects including skin irritation and toxic responses. The toxicity test of green tea extract also did not show any sign of irritation in the skin throughout the test period. Moderate severity of allergic contact dermatitis presented satisfactory clinical outcome at second week follow-up which was final visit of outpatient. This result mean that green tea extract has a positive effect for managing allergic contact dermatitis but its potency and efficacy seem to be so not strong enough to control moderate severity allergy skin lesion. In this pilot study, we were able to conclude that green tea cell extracts might be applied for potential anti-inflammatory soaking without skin toxicity.

• The Journal of the Acoustical Society of Korea
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• v.39 no.2
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• pp.113-119
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• 2020

Motor noise is a major concern in order to improve perceptual feeling of car interior sound due to increased motor usage in passenger cars. The purpose of this study is to propose factors that can represent the acoustic performance of motor noise according to the change of load. To this end, at first, it is shown that power spectrum and total loudness are not fit for noise performance, and then, PN_B, partial loudness related to the brush friction component, and PN_R, partial loudness related to the torque ripple component are investigated as factors representing motor noise. The performance curve of motor noise using PN_B and PN_R is proposed to identify trends of motor noise according to the loads. The curve could be a guide for the noise control, the selection of motor, and the improvement of a system.

• Parasites, Hosts and Diseases
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• v.53 no.1
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• pp.113-117
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• 2015

Cryptosporidium spp., ubiquitous enteric parasitic protozoa of vertebrates, recently emerged as an important cause of economic loss and zoonosis. The present study aimed to determine the distribution and species of Cryptosporidium in post-weaned and adult pigs in Shaanxi province, northwestern China. A total of 1,337 fresh fecal samples of post-weaned and adult pigs were collected by sterile disposable gloves from 8 areas of Shaanxi province. The samples were examined by Sheather's sugar flotation technique and microscopy at${\times}400$ magnification for Cryptosporidium infection, and the species in positive samples was further identified by PCR amplification of the small subunit (SSU) rRNA gene. A total of 44 fecal samples were successfully amplified by the nested PCR of the partial SSU rRNA, with overall prevalence of 3.3%. The average prevalence of Cryptosporidium infection in each pig farms ranged from 0 to 14.4%. Species identification by sequencing of SSU rRNA gene revealed that 42 (3.1%) samples were Cryptosporidium suis and 2 (0.15%) were Cryptosporidium scrofarum. C. suis had the highest prevalence (7.5%) in growers and the lowest in breeding pigs (0.97%). C. suis was the predominant species in pre-weaned and adult pigs, while C. scrofarum infected pigs older than 3 months only. A season-related difference of C. suis was observed in this study, with the highest prevalence in autumn (5.5%) and the lowest (1.7%) in winter. The present study provided basic information for control of Cryptosporidium infection in pigs and assessment of zoonotic transmission of pigs in Shaanxi province, China.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.6
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• pp.113-119
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• 2013

A main oxidizer shut-off valve (MOV) controls the supply of cryogenic liquid oxygen to the combustion chamber of liquid rocket engines by on/off operations. The main subjects to be introduced are not only the valve transient response during valve on/off procedures but also the characteristics of pneumatic and seat/poppet parts as core technologies in the development of the MOV, which is expected to be adopted for the Korea Space Launch Vehicle II. It is shown that the analytical prediction of the transient valve travel is in good agreement with experimental results. Friction and elastic forces on the valve moving part are quantitatively evaluated by structural analysis.

• Journal of the Korean Society for Heat Treatment
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• v.30 no.3
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• pp.113-116
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• 2017

100 nm thick Sn doped ZnO (ZTO) single layer, 15 nm thick Ag buffered ZTO (ZTO/Ag), Ag intermediated ZTO (ZTO/Ag/ZTO) and Ag capped ZTO (Ag/ZTO) films were prepared on poly-carbonate (PC) substrates by RF and DC magnetron sputtering and then the influence of the Ag thin film on the optical and electrical properties of ZTO films were investigated. As deposited ZTO thin films show the visible transmittance of 81.8%, while ZTO/Ag/ZTO trilayer films show a higher visible transmittance of 82.5% in this study. From the observed results, it can be concluded that the 15 nm thick Ag interlayer enhances the opto-electrical performance of ZTO thin films effectively for use as flexible transparent conducting oxides films in various opto-electrical applications.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.1
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• pp.113-119
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• 2017

An investigation on aerodynamic performance of a highly-loaded axial fan has been conducted to find the effects of tip injection and casing groove on aerodynamic performance in this study. Three-dimensional Reynolds-averaged Navier-Stokes equations with $k-{\varepsilon}$ turbulence model were used to analyze the fluid flow in the fan with Fluid-Structure Interaction (FSI) analysis. The hexahedral grid was used to construct computational domain, and the grid dependency test drew the optimal grid system. FSI analysis was also carried out to predict the deformation of rotor and stator blades, and the effect of deformation on the aerodynamic performance of axial fan was analyzed compared to the performance predicted without FSI analysis.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.3
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• pp.113-118
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• 2012

Collision detection plays a key role in collision mitigation system. The malfunction of the collision mitigation system can result in another dangerous situation or unexpected feeling to driver and passenger. To prevent this situation, the collision time, offset, and collision decision should be determined from the appropriate collision detection algorithm. This study focuses on a method to determine the time to collision (TTC) and frontal offset (FO) between the ego vehicle and the target object. The path prediction method using the ego vehicle information is proposed to improve the accuracy of TTC and FO. The path prediction method utilizes the ego vehicle motion data for better prediction performance. The proposed algorithm is developed based on laser scanner. The performance of the proposed detection algorithm is validated in simulations and experiments.

• The Korean Journal of Mycology
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• v.44 no.2
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• pp.113-117
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• 2016

The biodiversity of endophytic fungi on Thuja koraiensis in Mt. Hwaak, Seorak, and Hambaek, Korea was investigated. For the 202 isolates collected from the host trees, internal transcribed spacer rDNA region sequences-based analysis identified 32 taxa; 61.5% of the isolates belonged to Dothideomycetes, 27.0% belonged to Sordariomycetes, and 11.5% belonged to Leotiomycetes. This composition rate is somewhat different from that reported in previous studies for endophytic fungi inhabiting trees of the family Pinaceae. In particular, Phyllosticta spinarum in Dothideomycetes is a dominant species among the diverse endophytes of T. koraiensis. Therefore, further critical research is required for this species.

• The Korean Journal of Mycology
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• v.37 no.1
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• pp.108-110
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• 2009

The composition of endophytic fungal species from Pinus koraiensis was studied in two areas (Yeongwol and Jincheon), Korea. To identify 113 isolates, rDNA ITS regions were sequenced. On the basis of the ITS sequence, Pestalotiopsis sp. was the most frequently isolated species in both areas. Pestalotiopsis sp. (68.5%) and Lambertella sp. (12.4%) were isolated frequently in Yeongwol, whereas Pestalotiopsis sp. (41.7%), Hypoxylon sp. (20.8%) and Phomopsis sp. (12.4%) were dominant in Jincheon. Hypoxylon sp. and Phomopsis sp. were not found in Yeongwol.