• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book II
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• pp.528-528
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• 2003

The present study was undertaken to develop the in vitro sun protection factor(SPF) test method having good correlation with in vivo method using human. 8% homomentyl salicylate, P3 reference standard and commercially available sunscreen products were measured by the in vitro method using SPF 290S analyzer, and the SPFs were compared with the SPFs measured by in vivo test method. In vitro SPFs of 8% HMS and P3 reference standard were 4.59 $\pm$ 0.12 and 14.94 $\pm$ 0.83. There are good correspondence, correlation coefficients were 0.9506 and 0.9769 respectively, between the in vitro and in vivo SPFs for the sunscreen creams and lotions. Correlation coefficients of makeup base/liquid foundation, lotion labled with "shake before use" and compact powder were 0.8812, 0.8632 and 0.5984 respectively. The optimum mixture ratio of compact powder and cream base represents 1:0.8. These results suggest that the in vitro SPF test method will be able to be used as an alternative method for in vivo SPF in case of lotion and cream.

• 대한소아치과학회지
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• 제26권1호
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• pp.88-95
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• 1999

구강내의 교정 장치는 미생물 전파에 있어서 다양한 장소를 제공한다. 치태는 치아 우식증 발생에 있어 매우 큰 역할을 하며 미생물, 비세포성 물질로 구성되어 있다. 본 연구의 목적은 생체외에서 교정용에서의 인공 치태 생성에 영향을 주는 요인을 평가하는 것이다. Streptococcus mutans type c는 $CO_2$ incubator내의 $37^{\circ}C$에서 brain heart infusion broth에서 배양 되었다. 중절치에 사용하는 9개의 $.018"{\times}.025"$ standard edgewise brackets을 3개씩 비이커의 배양액에 매달았다. 3개 비이커의 배양액 pH는 각 각 pH 5.5, 7.0 그리고 8.5로 조절되었다. 5시간 후에 비이커에서 각각의 bracket을 꺼내서, bracket의 평균 무게를 측정하였다. 배지의 stirring effect를 측정하기 위하여 3개씩 $.018"{\times}.025"$ standard edgewise brackets을 2개의 비이커에 위치시켰다. 12개의 brackets을 $CaCl_2$(0.25, 1.0, 4.0 그리고 16.0mM). KCl(2.5, 10, 40 그리고 160mM) 그리고 $MgCl_2$(0.1, 0.4, 1.6, 그리고 6.4mM) 용액에 각각 매달았다. 6개의 $.018"{\times}.025"$ standard edgewise brackets, 6개의 $.022"{\times}.028"$ Roth brackets과 6개의 $.022"{\times}.028"$ Broussard brackets을 각각의 비이커 내에 매달았다. 배양액 내에서 5시간 동안 배양한 후 각각의 brackets을 근사값의 milligram 단위로 측정하였다. 그룹 사이의 차이는 Mann-Whitney와 Kruskal-Wallis tests를 이용하여 비교하였다. p value<0.05의 조건에서 이들의 차이는 통계학적 유의성을 갖는다. 5시간 동안 pH 5.5에서 배양된 Streptococcus mutans에 의해 형성된 인공 치태는 pH 7.0 이나 pH 8.5에서 배양된 것보다 작았다(p<0.05). 인공 치태는 배양하는 동안 저어졌을 때 더 많이 형성되었다(p<0.05). 결론적으로 bracket에 형성된 인공 치태는 좀 더 높은 알칼리성 배지에서 배양됨으로써, 그리고 배양 동안 배지를 저어줌으로써 유의성있게 증가하였다. 그러나 배지의 $CaCl_2,\;KCl,\;MgCl_2$의 농도와 상업적으로 다른 종류의 이용 가능한 교정용 bracket에 대해서는 유의한 차이가 없었다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.402-406
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• 2006

The physical and chemical characteristics of ALC were analyzed and showed 2.2 of specific gravity and 9.05 of pH. The results of leaching tests with standard method for soil and waste indicated heavy metals(Cu, Cd, Pb, $Cr^{6+}$) were under maximum concentration level. The anaerobic digestion sludge was attached in the surface of ALC within 90 hours. As the results of batch test, pH of the ALC and Bio-ALC were decreased from initial pH of ALC to 8.7 and 7.8 respectively Also, the concentration of heavy metals was rapidly eliminated in the solution with the batch test. The result of column experiment indicates that the removal efficiency of ALC was showed 66% of T-P, 60% of T-N, and 67% of CODcr. Also, removal efficiency of Bio-ALC was slightly higher than that of ALC in T-N (64%) and CODcr (74%).

• 대한임상전기생리학회지
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• 제1권1호
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• pp.1-15
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• 2003

The purpose of this study was to determine the effect of neuromuscular electrical stimulation(NMES) on the alteration of spinal motor neuron excitability. In this article, I would like to experiment on a standard capacity of clinical electrophysiology, a difference in applying methods and a clinical efficiency of NMES by Nerve conduction velocity. We used normal eight subjects without neuromuscular disease and all subjects participated 3 session, which at least 1 week between session. Participants classified according to each group in Antagonist, Agonist, Antagonist-Agonist by the NMES. The test was measured continuously pre test, post-test, post 20 minute test by EMG including H reflex, F wave, motor nerve conduction velocity(MNCV). The following results were obtained; 1. H-reflex latencies and H/M intervals were significantly increased in agonist and antagonist-agonist group(p<.01). 2. H-reflex amplitudes and H/M ratios were significantly decreased in agonist and antagonist-agonist group(p<.01). In agonist group, H-reflex amplitudes and H/M ratios were more significantly decreased than antagonist group. 3. F-wave latencies were significantly increased in agonist and antagonist-agonist group(p<.01). F/M intervals were significantly increased in antagonist-agonist group(p<.01). F wave conduction velocities were significantly increased in agonist and antagonist-agonist group(p<.01) but F/M ratios were not significant. 4. MNCV were significantly decreased in agonist(p<.01). These results lead us to the conclusion that agonist and Antagonist-agonist was significantly decreased excitability of spinal motor neuron. Conversely, Antagonist does not decreased. Therefore, A further direction of this study will be to provide more evidence that NMES have an effect on excitability of spinal motor neurons in UMN syndrome.

• Corrosion Science and Technology
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• 제6권5호
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• pp.257-260
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• 2007

In order to further improve the corrosion resistance and wear resistance of the Ni-P coatings of electroless plating, electroless Ni-P/n-$Al_2O_3$ composite deposits were prepared by adding some nano $Al_2O_3$ Particles in Ni-P plating bath. The bath composition and proproties were studied in this paper. The orthogonal test was applied in order to get the new composite solution, taking the initial stable potential as evaluation standard and considering the elements correlation at the same time. The processing parameters have been optimized by single factor experiment in which the depositing speed was chosen as the evaluation standard. The results showed that the process is stable and the composite Ni-P/n-$Al_2O_3$ deposits werebright and smooth, whose hardness and corrosion resistance are much better than simple Ni-P coatings. Furthermore the surface appearance and structure of the composite Ni-P/n-$Al_2O_3$ coating were investigated by SEM and XRD method. It was proved that the coating surface is typical cystiform cells and its structure is amorphous. All test results ofcomposite coating showed that all various physical coating properties had been improved by adding nano-particles. The hardness of optimal coating is more than 600HV and increases to 1000HV after heat-treating, and its hardness is 20~50% higher than Ni-P coating. The rust points appeared in 200 hour by immersing the coating into the 10%HCl solution and the corrosive speed is $3{\times}10^{-3}mg/(cm^2{\cdot}h)$which was obtained after 300 hour. In the same condition Ni-P coating is $5.6{\times}10^{-3}mg/(cm^2{\cdot}h)$. The salt spray resistance of the layers can exceed 600h with the thickness $20{\mu}m$.

• 한국지반환경공학회 논문집
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• 제7권6호
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• pp.121-131
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• 2006

본 연구는 아파트공사 굴착현장에서 많이 사용하고 있는 LW주입의 지반보강효과와 환경 영향성에 대한 검토를 목적으로 수행되어 졌다. 아울러 본 연구는 투수계수가 작은 지반에서 LW공법의 지반보강효과를 현장조사 및 실내시험으로 공학적인 규명을 하였고 환경영향성 시험을 실시하여 친환경성에대한 평가를 실시 하였다. 실내시험결과 SC류인 토질성상의 지반에 대한 LW고결체는 원지반에 비해 일축압축강도는 약 3배, 전단강도정수는 약 2배 증가되고 투수계수는 6~7배 감소되어 상당한 개량효과가 있는 것으로 나타났으며 환경영향성평가 결과 pH가 초기에는 7.96까지 증가하였으나 6시간 이후부터 감소하기 시작하여 80시간 이후에는 7.30으로 초기 pH 7.25를 회복하였고, 화학성분분석 시험결과 원수와 오염수의 수소이온농도(pH)가 원수는 pH 7.36, 오염수는 pH 7.85로서 "환경부 먹는물의 수질기준"에 의거, 기준치(pH 5.8~8.5) 범위 내 이므로 환경적으로 안전하였고 원수 및 오염수에 대한 염분 및 $Cr^{6+}$ 측정 시험결과 염분은 미미하며 $Cr^{6+}$은 미검출되어 친환경적임을 알 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기물성,응용부문
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• pp.34-36
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• 2002

The objective of this study is to develop the composite insulator for 170kA disconnecting switch. In this paper, we have investigated the test procedure about each component(FRP tube, flange, shed) through technical standard(IEC 61462) and obtained demand characteristics by mechanical & electrical property test.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1998년도 공동 심포지엄 및 추계학술발표회
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• pp.156-161
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• 1998

As grouting materials for ground improvement, silicate materials such as water glass, silica-sol and so forth are used worldwide. However, they may pollute underground water. In this study, fish poison test(Korean standard industrial code KS M 0111) which estimates toxicity for fish is applied to evaluate the toxic effect by grouting materials. From the test result of the sample made of LW, LC50(Median Lethal Concentration) reaches within 24 hours. In case of the silica-sol, it does not even in 96 hours. Therefore, we can conclude that the sililca-sol grouting method is more free from the danger of underground water pollution. From the result that the mortality of fish under the condition of pH 8.6 is 0% within 96 hours, the groundwater can be saved by controlling pH below 8.6 for the grouting in the field.

• 대한후두음성언어의학회지
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• 제18권2호
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• pp.102-107
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• 2007

Laryngopharyngeal reflux disease (LPRD) is the result of retrograde flow of gastric contents to the laryngopharynx. Laryngoscopic findings and special questionnaires are first step of diagnosis of LPRD. Empiric trials of Proton pump inhibitor' test (PPI test) is recommended as treatment and diagnosis. However confirmation of reflux is then recommended primarily in patients with persistent symptoms despite acid-suppressive therapy. The 24 hour ambulatory double pH monitoring has been a gold standard method in diagnosis of LPRD even though it has some limitation. The combined multichannel intraluminal impedance and pH monitoring is a new-rising test tool. It can detect acid/non-acid, liquid/gaseous reflux and clearance of refluxate. The water siphon test is also used for diagnosis of LPRD.

• Animal Bioscience
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• 제35권1호
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• pp.147-152
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• 2022

Objective: This study was conducted to obtain an objective index that can be quantified and used for establishing an animal welfare certification standard in Korea. For this purpose rumen pH, ruminating time, milk yield, milk quality, and blood components of cows reared in farms feeding high forage level (90%) and farms feeding low forage level (40%) were compared. Methods: Data on rumen pH, rumination time, milk yield, milk fat ratio, milk protein ratio, and blood metabolism were collected from 12 heads from a welfare farm (forage rate 88.5%) and 13 heads from a conventional farm (forage rate 34.5%) for three days in October 2019. Results: The rumination time was longer in cattle on the welfare farm than on the conventional farm (p<0.01), but ruminal pH fluctuation was greater in the cattle on conventional farm than the welfare farm (p<0.01). Conventional farms with a high ratio of concentrated feed were higher in average daily milk yield than welfare farms, but milk fat and milk production efficiency (milk fat and milk protein corrected milk/total digestible nutrients) was higher in cattle on welfare farms. Blood test results showed a normal range for both farm types, but concentrations of total cholesterol and non-esterified fatty acid were significantly higher in cows from conventional farms with a high milk yield (p<0.01). Conclusion: The results of this study confirmed that cows on the animal welfare farm with a high percentage of grass feed had higher milk production efficiency with healthier rumen pH and blood metabolism parameters compared to those on the conventional farm.