• Environmental Analysis Health and Toxicology
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• 제4권1_2호
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• pp.11-17
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• 1989

A quantitative analytical method of highly concentrated PCB is established in the research. With the quantitative analytical method PCB of insulating oil was examined. The following conclusions are derived from this research. 1. The recovery ratio was 95.7% with the quantitative analytical method, which indicates it can be used for the analysis of PCB. 2. PCB concentration of insulation oil in waste condenser was found to be 21.2% thru 13.85% , which was highly concentrated. 3. PCB insulation oil in waste condenser was same as PCB-42.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1997년도 추계학술대회논문집; 한국과학기술회관; 6 Nov. 1997
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• pp.408-413
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• 1997

The linear dynamic response of a simply supported uniform beam under a moving load of constant magnitude is investigated. When the ratio of the moving weight and the structure weight is small, moving object is considered as a concentrated or distributed moving force, that is large external loading can be considered as a concentrated or distributed moving masses. Result from the numerical solutions of the differential equations of motion are shown graphically. Moreover, when considering the maximum deflection for the mid-span of the hewn, the critical speeds of the moving load have been evaluated.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1994년도 가을 학술발표회 논문집
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• pp.273-278
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• 1994

The shear behavior of simply supported reinforced concrete deep beams subject to concentrated loads has been scrutinized experimentally to verify the influence of the structural parameters such as shear span ratio, and the horizontal and vertical web reinforcements. A total of 27 specimens has been tested at the laboratory. In the tests all specimens have failed in shear causing inclined cracks from the load application points to the supports. The load bearing capacities have changed significantly depending on the shear span ratio. The effects of the vertical and horizontal reinforcements on the shear strength and crack initiation and propagation have been carefully checked and analyzed.

• 한국농공학회지
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• 제42권1호
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• pp.105-112
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• 2000

This paper deals with the free vibrations of columns immersed in fluid. The column model is based on the classical Bernoulli-euler theory which neblects the effects of rotatory inerital and shear deformation. The eccentricity and rotatory inertial of the concentrated mass at the top are taken into accuont. In the governing equation for the free vibration of column, thedensity of immersed part was midified to account for theadded fluid mass. The govering differential equations are solved numerically using the corresponding boundary conditions. The lowest four natural frequencies and corresponding mode shapes are calculated over a range of non-dimensional system parameters ; the mas density ration of fluid to column, the ratio of fluid depth to span length, the ratio of tip mass to total column mass, the dimensionless mass moment of inertia, and the eccentricity.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.577-582
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• 2000

This study is aimed to evaluate the shear strength of reinforced concrete deep beams subject to concentrated loads, using a simplified strut-tie model. For the shear strength prediction of deep beams, it is prerequisite to evaluate the effective width of strut and to verify the efficiency factors proposed by MacGregor et al.. The results analyzed by truss models have been compared with those calculated by domestic code for the existing data of 90 deep beam specimens. The shear strength of deep beams were reviewed with respect to concrete strength, the shear span-depth ratio, and the ratio of web reinforcements. The results showed that the shear strength of the proposed model gave a better agreement than the domestic code approach.

• The Korean Journal of Ceramics
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• 제3권4호
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• pp.235-238
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• 1997

Basic properties of new cement pastes based on the system $CaO-Al_2O_3-P_O_5-H_2O$were studied Phosphoric acid solutions and calcium dialuminate clinkers synthesized by the hydration-burning method were used for liquid and powder components of the paste, respectively Variation in the compositions of the paste was achieved by changing the liquid/powder ratio and the concentration of phosphoric acid solution. The hardening rate of the paste was so largely affected by the amount of phosphoric acid that hardening was inhibited with the low-concentrated solution but was explosively accelerated with the high-concentrated solution. The phosphoric acid solutions of concentration of 45~50% and the liquid/powder ratio of 0.5~1.5 were favoured for the high early-strength cement paste with the reasonable hardening rate and high strength. The binding phase of hardened paste was the dense amorphous gel of the system $CaO-Al_2O_3-P_O_5-H_2O$. in which the unreacted calcium dialuminate grains were embeded.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1992년도 가을학술발표회 논문집
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• pp.65-68
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• 1992

In characterizing a suspension, heterogenety is included onto the previous characterization using solids concentrations and flocculent characteristics, because of its importance in hydrodynamics. The mechanism of interface formation during the sedimentation of concentrated suspension (thickening) is investigated from a microcosm consisting of four particles in a same plane and a smaller particle below. The critical distances after shich interface forms are calculated as a function of particle size ratio when the small particle is located in the middle of the squre datermined by the large particles. The results shows that the critical separation distance increase as the size ratio approaches to one (homogeneous suspension). This conforms to the trend of existing observations that homogeneous suspensions create the solid-liquid interface at much lower concentration (at al larger separation distance) that the heterogeneous suspensions.

• Asian Pacific Journal of Cancer Prevention
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• 제17권sup3호
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• pp.201-204
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• 2016

This study aimed to quantify associations of the human development inequality (HDI) index with incidence, mortality, and mortality to incidence ratios for eight common cancers among different countries. In this ecological study, data about incidence and mortality rates of cancers was obtained from the Global Cancer Project for 169 countries. HDI indices for the same countries was obtained from the United Nations Development Program (UNDP) database. The concentration index was defined as the covariance between cumulative percentage of cancer indicators (incidence, mortality and mortality to incidence ratio) and the cumulative percentage of economic indicators (country economic rank). Results indicated that incidences of cancers of liver, cervix and esophagus were mainly concentrated in countries with a low HDI index while cancers of lung, breast, colorectum, prostate and stomach were concentrated mainly in countries with a high HDI index. The same pattern was observed for mortality from cancer except for prostate cancer that was more concentrated in countries with a low HDI index. Higher MIRs for all cancers were more concentrated in countries with a low HDI index. It was concluded that patterns of cancer occurrence correlate with care disparities at the country level.

• 공업화학
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• 제34권3호
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• pp.272-278
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• 2023

이 연구에서는 전류밀도와 전기삼투 현상이 전기투석(electrodialysis, ED)의 탈염성능에 미치는 영향을 분석하였다. 농축액의 농도를 10~200 g/L로 변화시키면서 정전압 조건에서 ED 실험을 진행하였다. ED 운전과정에서 스택에 공급되는 전류밀도와 전하량, 희석액과 농축액의 농도, 그리고 전기삼투에 의한 물 이동량을 측정하여 탈염성능을 분석하였다. 농축액의 농도가 증가함에 따라 이온교환막의 선택성이 감소하여 전류효율이 감소하였다. 또한 전류효율은 스택에 공급되는 전류밀도에 영향을 받는 것으로 나타났다. 전류밀도가 15 mA/cm² 이상에서는 역 확산이 억제되어 전류효율이 증가하였다. ED 운전과정에서 전기삼투에 의한 물 이동량을 분석하였다. 물 이동량은 농축액과 희석액의 농도비에 비례하여 증가하는 것을 알 수 있었다. 농도비가 100 이상에서는 삼투압에 의한 물 이동량이 급격히 증가하여 200 g/L 이상의 농축액을 얻는데 한계가 있는 것으로 나타났다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 봄 학술발표회논문집(II)
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• pp.457-462
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• 1998

An experimental study was carried out for hybrid steel beams with reinforced concrete ends. The purpose is to examine the shear strength and to develop the design methodology of the RC-S connection region. Tested were four beams which included a reference beam and three beams with various parameters. The reference beam was used to make a comparison with remaining specimens. The test parameters were focused mostly on the concentrated shear reinforcements. The ratio of concentrated shear reinforcements and their types were investigated in this study.