• 산업기술연구
• /
• 제18권
• /
• pp.77-86
• /
• 1998

This study is to provide the useful data for the design and construction of the geotechnical engineering works by collecting and analyzing the soil properties of granite soil in the Kangwon Province. Data base was obtained from 92 field sites in the Kangwon province divided into 15 areas based on administration district. Total numbers of data were 478. Correlations between soil constants, especially compaction properties, were obtained by performing statistical analysis. Analyzed results were as follows. 1. Most of granite soil consists of SM and GM based on United Soil Classification System. 2. Mean gravity of granite soil is 2.65 3. High correlations between optimum moisture content and the maximum dry density, plasticity index and liquid limit are obtained. 4. Analyzed results between other soil constants show relatively low correlation. However, they show consistent trends matchable to geotechnical engineering senses.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1993년도 하계학술대회 논문집 B
• /
• pp.912-915
• /
• 1993

In this paper, the speed of single phase induction motor driven by full bridge inverter is controlled by a PID controller under condition of disturbance load and setpoint changes, and the current characteristics of the system is investigated to look for the good properties of A.C. motor torque through the results of experiment. From the experimental result, it is confirmed that the speed of single phase induction motor driven by full bridge series inverter can be smoothly controlled by an analog PID controller.

• Journal of Microbiology and Biotechnology
• /
• 제24권10호
• /
• pp.1413-1420
• /
• 2014

Phytate is an antinutritional factor that impacts the bioavailability of essential minerals such as $Ca^{2+}$, $Mg^{2+}$, $Mn^{2+}$, $Zn^{2+}$, and $Fe^{2+}$ by forming insoluble mineral-phytate salts. These insoluble mineral-phytate salts are hydrolyzed rarely by monogastric animals, because they lack the hydrolyzing phytases and thus excrete the majority of them. The ${\beta}$-propeller phytases (BPPs) hydrolyze these insoluble mineral-phytate salts efficiently. In this study, we cloned a novel BPP gene from a marine Pseudomonas sp. This Pseudomonas BPP gene (PsBPP) had low sequence identity with other known phytases and contained an extra internal repeat domain (residues 24-279) and a typical BPP domain (residues 280-634) at the C-terminus. Structure-based sequence alignment suggested that the N-terminal repeat domain did not possess the active-site residues, whereas the C-terminal BPP domain contained multiple calcium-binding sites, which provide a favorable electrostatic environment for substrate binding and catalytic activity. Thus, we overexpressed the BPP domain from Pseudomonas sp. to potentially hydrolyze insoluble mineral-phytate salts. Purified recombinant PsBPP required $Ca^{2+}$ or $Fe^{2+}$ for phytase activity, indicating that PsBPP hydrolyzes insoluble $Fe^{2+}$-phytate or $Ca^{2+}$-phytate salts. The optimal temperature and pH for the hydrolysis of $Ca^{2+}$-phytate by PsBPP were $50^{\circ}C$ and 6.0, respectively. Biochemical and kinetic studies clearly showed that PsBPP efficiently hydrolyzed $Ca^{2+}$-phytate salts and yielded myo-inositol 2,4,6-trisphosphate and three phosphate groups as final products. Finally, we showed that PsBPP was highly effective for hydrolyzing rice bran with high phytate content. Taken together, our results suggest that PsBPP has great potential in the animal feed industry for reducing phytates.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
• /
• pp.1547-1550
• /
• 2008

We are suggesting a new index to represent the performance of PDP, such as Specific Performance Index (SPI) that includes luminous efficacy and panel reflectance. High Xe gas mixture and low panel capacitance are well known as key factors to improve luminous efficacy of PDP [1]. However, higher driving voltage and longer discharge time lag is an obstacle when applying these technologies. Modified cell design, new materials and driving waveform enable us to overcome these obstacles. High efficient phosphor is also a key material to improve luminous efficacy. Phosphors coated with pigment are used to reduce panel reflectance. High performance 50-inch HD PDP with luminous efficacy of 2.3 lm/W has been developed.

• Bulletin of the Korean Chemical Society
• /
• 제25권10호
• /
• pp.1508-1512
• /
• 2004

A gas chromatography/mass spectrometric (GC/MS) method has been developed for the determination of trace mono-n-butyltin (MBT), di-n-butyltin (DBT), and tri-n-butyltin (TBT) compounds in sediments. Samples were extracted by 10% acetic acid in methanol containing 0.03% tropolone and were then derivatized for GC/MS analysis. Ethylation by sodium tetraethylborate and phenylation by sodium tetraphenylborate were evaluated as a derivatization reaction of the organotins in sample extract. n-Hexane was added into reaction media in the beginning of the reaction for the continuous extraction of derivatized organotins. Ethylation requires less than 2 hours to get proper derivatization yields for MBT, DBT, and TBT altogether and produces relatively low amounts of side reaction products. Compared to ethylation, phenylation requires much longer time but provides relatively lower yield and produces considerable amounts of side reaction products. Therefore, the ethylation reaction was applied for the analysis of organotin compounds in sediment. An isotope dilution mass spectrometric (IDMS) method based on GC/MS has been applied to the accurate determination of DBT compounds in the sediments. The IDMS results from the analyses of sediment samples showed a reasonable repeatability and a good agreement with the values obtained by IDMS based on liquid chromatography/induced coupled plasma/mass spectrometry.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• 제12권1호
• /
• pp.1-9
• /
• 2009

목 적: 소아에서 대장의 림프 결절 증식은 비교적 드물다고 알려져 있으며 몇 예의 증례 또는 소규모 그룹에 대한 연구만 보고 되어 왔고 임상적인 의의가 아직 확립되어 있지 않다. 본 연구에서는 대장에 림프 결절증식 소견을 보였던 환아들의 임상적 특징, 검사 소견 및 조직학적 소견 등을 분석하여 이 소견에 대한 임상적 의의에 대하여 알아보고자 하였다. 방 법: 2003년 5월부터 2008년 10월까지 가천의대 길병원 소아청소년과에서 하부 소화관 내시경 검사를 시행 받은 환아들 중 검사 당시 육안적으로 대장의 림프결절 증식 소견을 보였던 38명을 대상으로 하였다. 내시경 검사를 받을 당시 성별, 연령, 출생력, 과거력 및 가족력을 조사하였으며 주 호소와 동반 증상, 식이 방법과 주요 신체 진찰 소견을 확인하였다. 혈액 검사, 대변 검사, 영상학적 검사를 시행하였으며 내시경 검사시 모든 환아에서 조직검사를 시행하여 이를 분석하였다. 내시경 검사 후 단기 및 장기 추적을 통해 증상의 경과를 관찰하였다. 결 과: 총 38명의 환아 중 남아가 24명(63.1%), 여아가 14명(36.9%)이었고 내원 당시 나이는 평균 12.5${\pm}$14.4개월이었으며 12개월 이하의 영아가 28명(73.6%), 13개월 이상의 소아는 10명(26.4%)이었다. 38명 모두 혈변을 주소로 내원하였다. 전체 환아 중 설사가 17명 (44.3%)으로 가장 많이 동반되었으며 점액성 변, 구토, 복통, 경구 섭취 부족, 발열, 변비 등의 동반 증상을 보였다. 모든 환아는 신체 진찰 상 비교적 건강해 보였다. 혈액 검사 상 헤모글로빈, 혈청 알부민, 혈액 응고 검사수치 등은 1예를 제외하고 모두 정상 범위였다. 대변세균 배양 검사, 영상학적 검사상 다른 출혈의 원인은 찾을 수 없었다. 조직검사 상 36예(94.7%)에서 림프 소절이 확인되었으며 34예(84.5%)에서 알레르기성 대장염의 조직학적 기준을 만족하였다. 단기 경과 추적이 가능했던 25명 중 20명에서 증상이 소실되었으며 장기경과 추적이 가능했던 33명 모두에서 증상이 호전되고 재발하지 않았다. 결 론: 대장의 림프 결절 증식 소견은 알레르기성 대장염과 관련하여 영아에서 더 흔하지만 소아 전 연령대에서 나타날 수 있다. 특히 비교적 건강한 소아에서 다른 하부 위장관 출혈의 원인을 찾을 수 없고 내시경상 LNHC를 보이면 이를 하나의 진단으로 간주할 수 있을 것이다. 증상은 식이 변경과 상관 없이 소실되었고 장기간 추적 관찰에서 재발하지 않아 양성 질환임을 확인할 수 있었다.

• BMB Reports
• /
• 제57권3호
• /
• pp.149-154
• /
• 2024

The stomach has emerged as a crucial endocrine organ in the regulation of feeding since the discovery of ghrelin. Gut-derived hormones, such as ghrelin and cholecystokinin, can act through the vagus nerve. We previously reported the satiety effect of hypothalamic clusterin, but the impact of peripheral clusterin remains unknown. In this study, we administered clusterin intraperitoneally to mice and observed its ability to suppress fasting-driven food intake. Interestingly, we found its synergism with cholecystokinin and antagonism with ghrelin. These effects were accompanied by increased c-fos immunoreactivity in nucleus tractus solitarius, area postrema, and hypothalamic paraventricular nucleus. Notably, truncal vagotomy abolished this response. The stomach expressed clusterin at high levels among the organs, and gastric clusterin was detected in specific enteroendocrine cells and the submucosal plexus. Gastric clusterin expression decreased after fasting but recovered after 2 hours of refeeding. Furthermore, we confirmed that stomachspecific overexpression of clusterin reduced food intake after overnight fasting. These results suggest that gastric clusterin may function as a gut-derived peptide involved in the regulation of feeding through the gut-brain axis.

• 산업기술연구
• /
• 제22권A호
• /
• pp.229-240
• /
• 2002

This paper is an experimental and numerical work of Investigating the bearing capacity of shallow foundation of rubble mound under eccentric loads. Parametric centrifuge model tests at the 50g level environments with the model footings in the form of strip footing were performed by changing the loading location of model footing, relative density and materials for ground foundation. For the model ground, crushed rock sampled from a rocky mountain was prepared with a grain size distribution of having an identical coefficient of uniformity to the field condition. Model ground was also prepared with relative densities of 50 % and 80 %. For loading condition, model tests with and without eccentric load were carned out to investigate the effect of eccentric loads and a numerical analysis with the commertially available software of FLAC was performed. For numerical estimation with FLAC, the hyperbolic model of a nonlinear elastic constitutive relationship was used to simulate the stress-stram constitutive relationship of model ground and a series of triaxial compression test were carried out to find the parameters for this model Test results were analyzed and compared with Meyerhof method (1963), effective area method based on the limit equilibrium method, and a numerical analysis with FLAC.

• 산업기술연구
• /
• 제22권A호
• /
• pp.145-151
• /
• 2002

This paper is results of extensive centrifuge model experiments about design factors influencing the bearing capacity and the settlement behaviors of SCP (Sand Compaction Pile). Centrifuge model tests were carried out changing design factors for SCP method such as replacement area ratio (as= 20, 40, 70%), Improvement ratio to footing width (W/B = 1, 2, 3), and amount of fines m sand pile (#200 = 5, 10, 15). Therefore, the effects of these design factors on the bearing capacity and the settlement behavior of SCP were investigated and changes of stress concentratio rato due to such an design factors were also investigated. Centrifuge model testing technique for preparing and installing centrifuge model of sand compaction pile, using freezing them, was also developed. As results of centrifuge model tests, more fines in sand compaction pile increases the bearing capacity of SCP. Optimum improvement ratio to footing width was found to be 2. Values of stress concentration ratio was in the ranges of 1.5 - 3.5. The depth of bulging in sand plies was found in the range of 2.0 - 2.5 times of pile diameter.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2005년도 지반공학 공동 학술발표회
• /
• pp.698-705
• /
• 2005

This study contains actual scaled site experiments on mediation factors affecting ultimate pulling force of the buoyancy resisting anchor which is installed underground water level suffering buoyancy force and breaking mechanism. Site buoyancy test selected the buoyancy acting site where acting buoyancy to the station structure since the stream and reservoir is neighboured to the vicinity ground and executed site experiments leading to variation of anchoring length, drilling diameter and tendon diameter at the weathered rock ground. The test result showed that pulling force getting increased more and more proportionate to increase of anchoring length, drilling diameter and tendon diameter, and as a result of analysis for correlations between anchoring length-ultimate limited load and drilling diameter-ultimate load (on the basis of 254mm settlement), modulus of correlation showed very high relation 0.9 and 0.99 respectively and correlation formular showed the limited load is increasing proportionate to cubic meters of anchoring length as well as the ultimate load proportionate to alignment of drilling diameter. It is also showed that limited load increased about 42.5% from 392kN to 559kN as a result of change the tendon diameter to 36mm and 50mm.