• 설비공학논문집
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• 제9권2호
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• pp.93-103
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• 1997

This study presents a way of improving the stability of fixed scroll in scroll compressors. For the scroll compressor whose fixed scroll is designed to move in the axial direction for the axial compliance, the fixed scroll is under the influence of the overturning moment produced by internal gas forces. Unless the overturning moment is properly compensated by the moments of reaction forces at the suspension of the fixed scroll to the compressor frame, the fixed scroll would exhibit wobbling motion, increasing gas leakage through the gap induced by the wobbling of the fixed scroll between the two scroll members. The conditions on which the wobbling motion can be suppressed have been found analytically; The axial position of the fixed scroll suspension should be made within a certain range. The upper limit of this range is the axial location for the o-rings which are inserted between the fixed scroll and the back pressure chamber to promote sealing for the gas in the back pressure chamber. And the lower limit is mainly determined by the magnitude of the axial sealing force. As long as the axial sealing force is not negative over all crank angles, the lower limit is not above the mid-height of the scroll wrap. Larger axial sealing force lower the lower limit.

• Child Health Nursing Research
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• 제15권1호
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• pp.71-80
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• 2009

Purpose: This study was done to investigate the effects of an infant massage on physical growth and stress response in preterm babies. Method: A nonequivalent control group with pre-posttest design was used with 56 preterm babies in the NICU of E medical center at Daejeon. Data were collected from July 2004 to May 2005. The intervention was given for 15 minutes, once a day for 7 days. Physical growth was measured by weight, length, head circumference, and stress response was measured by serum cortisol level. Mean, %, paired-test, t-test with the SPSS/W in 16.0 program were used to analyze the data. Results: After the intervention, physical growth variables (weight, length, head circumference) in experimental group were higher than that of the control group. Also, the serum cortisol level in the experimental group was lower than that of the control group. But none of these results were not statistically significant. Conclusion: The results of this study suggest that a 7-day intervention period may not be long enough to confirm the effects of infant massage on physical growth and stress reaction. Therefore it is suggested that a longer period of infant massage should be tested to determine if it is effective in improving the physical growth and stress reduction in preterm babies.

• 한국수소및신에너지학회논문집
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• 제8권4호
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• pp.161-171
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• 1997

$AB_2$ type Zr-based Laves phase alloys have been studied for potential application as negative electrode in Ni/MH batteries. However, They have a serious disadvantage of poor activation behavior in KOH solution. In this work, a new method of alloy design method was tried for improving Zr-based alloy activation. this method has focused on phase controlling to make multi-phase microstructure. In the case of multi-phase Zr-V-Mn-Ni shows good performance in activation, but activation mechanism has not been known. So, we were in search of elucidating this mechanism, Using morphological and electrochemical analysis, we could find that surface morphology and electocatalytic activity of the alloy change during immersion in KOH solution. V-rich second phases are selectively corroded and dissolved and then become Ni-rich phases. Resulting from these surface reaction in KOH solution, self-hydrogen charging occurs through Ni-rich phase. However, the alloy has poor cyclic durability because of such a corrosion mechanism. Therefore, finally we developed durable alloys by substitution of other alloying element.

• 한국정밀공학회지
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• 제19권6호
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• pp.77-85
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• 2002

An analysis method which calculates corrective machining information for improving the motion accuracy of linear motion guide Is proposed in this paper. The method is composed of two algorithms. One is the algorithm fur prediction of the motion errors from rail form error. The other is the algorithm for prediction of rail form error from the motion errors of table. Transfer function is utilized in each algorithm, which represents the ratio of bearing reaction force variation to unit magnitude of spatial frequencies of raid from error. As the corrective machining information is acquired from the measured motion errors of table, the method has a merit not to measure rail form error directly. Validity of the method is verified both theoretically and experimentally. By applying the method, linear motion error of test equipment is reduced from 5.97$\mu$m to 0.58$\mu$m, and reduced from 32.78arcsec to 6.21 arcsec in case of angular motion error. From the results, it is confirmed that the method is very effective to improve the motion accuracy of linear motion guide.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 창립총회 및 춘계학술발표회
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• pp.108-111
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• 2000

FeS/FeS$_2$ minerals have been known to be potentially useful reductant to the removal of common organic contaminants in groundwater and soil. This research is aimed at improving our understanding of factors affecting the pathways and rates of reductive transformation of Hexachloroethane by catalytical iron minerals in natural system. Hexachloroethane is reduced by FeS/FeS$_2$ minerals under anaerobic condition to tetrachloroethylene and trichloroethylene with pentachloroethyl radical as the intermediate products. The kinetics of reductive transformations of the Hexachloroethane have been investigated in aqueous solution containing FeS, FeS$_2$. The proposed reduction mechanism for the adsorbed nitrobenzene involves the electron donor-acceptor complex as a precursor to electron transfer. The adsorbed Hexachloroethane undergo a series of electron transfer, proton transfer and dehydration to achieve complete reduction. It can be concluded that the reductive transformation reaction takes place at surface of iron-bearing minerals and is dependent on surface area and pH. Nitrobenzene reduction kinetics is affected by reductant type, surface area, pH, the surface site density, and the surface charge. FeS/FeS$_2$-mediated reductive dechlorination may be an important transformation pathway in natural systems.

• Journal of Microbiology and Biotechnology
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• 제25권7호
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• pp.1101-1107
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• 2015

The role of CRE1 in a thermophilic fungus, Myceliophthora thermophila ATCC42464, was studied using RNA interference. In the cre1-silenced strain C88, the filter paper hydrolyzing activity and β-1,4-endoglucanase activity were 3.76-, and 1.31-fold higher, respectively, than those in the parental strain when the strains were cultured in inducing medium for 6 days. The activities of β-1,4-exoglucanase and cellobiase were 2.64-, and 5.59-fold higher, respectively, than those in the parental strain when the strains were cultured for 5 days. Quantitative reverse-transcription polymerase chain reaction showed that the gene expression of egl3, cbh1, and cbh2 was significantly increased in transformant C88 compared with the wild-type strain. Therefore, our findings suggest the feasibility of improving cellulase production by modifying the regulator expression, and an attractive approach to increasing the total cellulase productivity in thermophilic fungi.

• 동의생리병리학회지
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• 제31권6호
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• pp.380-384
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• 2017

From March 1, 2017 to May 31, 2017, subjects were allowed to apply a wrinkle-improving herbal cosmetic product containing the extract of Douchi for 8 weeks. The effectiveness of herbal cosmetics was evaluated through wrinkle improvement efficacy parameter analysis, subjective wrinkle improvement through questionnaires, and adverse reaction. The herbal cosmetic products containing the extract of Douchi showed a significant decrease in the wrinkle improvement efficacy parameter analysis result. The results of the subjective satisfaction analysis after use were also evaluated positively. We could confirm the possibility of wrinkle improvement effect of Douchi extract, and it will be possible to contribute to the expansion of korean medicine field through more studies in the future.

• 한국주조공학회지
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• 제33권3호
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• pp.122-126
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• 2013

Recently, heat-resistant aluminum alloy has been re-focused as a downsizing materials for the internal combustion engines. Heat-resistant Al alloy development and many researches are still ongoing for the purpose of improving thermal stability, high-temperature mechanical strength and fatigue properties. The conventional principle of heat-resistant Al alloy is the precipitation of intermetallic compounds by adding a variety of elements is generally used to improve the mechanical properties of Al alloys. Heat resistant aluminum alloys have been produced by CrW homogeneous solid solution to overcome the limit of conventional heat resistant aluminum alloy. From EPMA, it is found that CrW homogeneous soild solution phases with the size of $50-100{\mu}m$ have been dispersed uniformly, and there is no reaction between aluminum and CrW alloy. In addition, after maintaining at high temperature of 573 K, there is no growth of hardening phase, nor desolved, but CrW still exists as a homogeneous solid solution.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.541-544
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• 2001

Orthorhombic $LiMnO_2$ was synthesized by solid-state reaction using $LiOH{\cdot}H_{2}O$ and $Mn_{2}O_{3}$ as starting material. Its electrochemical properties as cathode in lithium batteries were examined. X-ray diiffraction revealed that the $LiMnO_2$ compound showed a well-defined orthorhombic phase of a space group with Pmnm. The capacity of $LiMnO_2$ agreed well with its specific surface area and grinding treatment was effective in improving cycling performance. For lithium polymer battery applications. the $LiMnO_2$ cell was characterized electrochemically by charge-discharge experiments. And the relationship between the characteristics of powder and electrochemical properties was studied in this research. A maximum discharge capacity of $160-170mAhg^{-1}$ for $LiMnO_2/Li$ cell was achieved.

• The Korean Journal of Pain
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• 제9권1호
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• pp.239-243
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• 1996

MS-Contin is an oral controlled-release preparation of morphine sulfate that has been used widely in the management of advanced cancer pain. It prolongs plasma concentration of morphine with no observable accumulation properties following repeated dosing, thereby promoting uninterrupted sleep and hopefully improving patient's quality of life. The common side effects of MS Contin are nausea, vomiting, drowsiness and constipation. But these symptoms are usually mild and respiratory depression is a rare problem. We experienced respiratory depression during oral administration of MS contin for the pain management of advanced gall bladder cancer of 76 years old male patient with metastasis at liver, intestine and cervical lymph node. After we increased the dosage of MS Contin from 160mg to 220mg per day, due to abdominal pain, we observed morphine reaction of MS Contin overdose such as pinpoint pupil, deeply slow respiration below 8/minute, and drowsiness. After intravenous bolus injection of 0.4 mg naloxone followed by continuous administration of 0.2 mg/hr for 4 hours, the patient regained consciousness. The administered route of morphine was changed to intravenous PCA (patient controlled analgesia). There was no aspiration sign as confirmed by chest x-ray. The patient was comfortable and delayed no signs of respiratory depression until now.