• Tribology and Lubricants
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• 제13권2호
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• pp.74-81
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• 1997

The purpose of this study is to develop a cold rolling oil with lubricity and mill cleanness property under the rolling conditions of high reduction ratio and high rolling speed. Six kinds of oil samples were blended. Evaluation of lubricity and anti-seizuro property of the samples were carried out with a laboratory scale rolling mill, where the contact conditions between work roll and strip are very close to actual cold rolling mill. Laboratory evaluation for dispersion, contamination, anti-oil stain property and residual carbon, etc. were carried out with several testers such as longterm circulation tester, Coulter counter and Conradson tester. A new high speed cold rolling oil with good lubricity and mill cleanness property was developed compared with the previously developed rolling oil.

• Journal of Yeungnam Medical Science
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• 제10권1호
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• pp.58-67
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• 1993

1986년 5월부터 1991년 6월까지 약 5년간 영남대학교 외과대학 부속병원에 내원하여 혈액학적 소견상 빈혈이 동반된 환자 210명과 정상인 200명 도합 410명을 대상으로 Coulter Counter S-plus II로 일반혈액검사를 실시하여 MCV와 RDW 및 여러 적혈구 지수를 얻어서 빈혈의 새로운 분류를 시도하였고 외국인에 비하여 빈혈의 병인 양상이 다른 한국인의 혈액질환의 감별진단에 도움이 되는 가를 알아 보고자 본 연구를 시행하였다. 거의 모든 경우에 MCV의 증감은 MCH와 MCHC의 증감을 동반하였으나 RDW와는 무관하였다. 따라서 저색소성빈혈 혹은 정색소성빈혈등의 용어보다는 이질성빈혈 혹은 동질성빈혈의 용어를 사용함이 빈혈의 형태학적 분류에 더욱 의미있는 것으로 사료되었다. 이질성소구성빈혈에는 철결핍성빈혈이 속하였고 이질성정구성빈혈에는 급성백혈병과 골수로성빈혈이 여기에 속하였으며 이질성대구성빈혈에는 거대적아구성빈혈과 용혈성빈혈이 속하였다. 동질성소구성빈혈에는 만성질환에 의한 빈혈이 여기에 속하였으며 동질성정구성빈혈에는 급성출혈, 만성백혈병 및 다발성 골수종등에 의한 빈혈이 여기에 속하고 동질성대구성빈혈에는 재생활량성빈혈이 여기에 속하였다. 진단적인 의의가 큰 혈색소병은 본 연구에는 관찰되지 않았지만 한국인에 가장 많은 빈혈의 원인인 철결핍성빈혈과 만성질환에 의한 빈혈의 감별진단에 RDW가 유용한 것으로 생각되었다.

• 한국산업보건학회지
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• 제18권3호
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• pp.177-184
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• 2008

The purpose of this study was to compare the performance characteristics of Andersen and total suspended particulate (TSP) samplers in terms of particle size distribution (PSD) and mass sampling efficiency. In the present study, two Andersen and four TSP samplers were selected and tested to quantitatively estimate human exposure to fly ash representing industrial particulate matter (PM) in a carefully controlled chamber. The PSD characteristics, a mass median aerodynamic diameter and a geometric standard deviation, were found from the sampled PM of airborne samplers in the chamber. An Andersen sampler was compared with a TSP sampler quantified by a coulter counter multisizer, as a reference sampler, to describe the correlation of mass sampling efficiencies between two types of samplers. Overall results indicate that Andersen samplers overestimated small PM due to particle bounce phenomena between impaction stages. There was reasonably good correlation ($R^2$ = 0.89 and 0.91) between the mass sampling efficiencies of Andersen and TSP samplers during the two tests. However, the lower values of slope (0.71 and 0.72) in two tests showed that the Andersen sampler underestimated PM (> AD $10.1\;{\mu}m$) with sufficient inertia due to a relatively lower Andersen inlet velocity at 0.8 m/s comparing with the operating air velocity at 2.1 m/s in the sampling zone of a chamber.

• Journal of Pharmaceutical Investigation
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• 제17권1호
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• pp.38-40
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• 1987

To optimize the preparation condition of oil in water microemulsion rheological method was used. The viscosity-temperature curve of refined soybean oil was recorded and from this result microemulsion was prepared at various temperatures and evaluated by Coulter counter during 3 weeks. The difference in rheograms of crude emulsion and the microemulsion varying the number of passes in the homogenizer was also examined. From above experiments following conclusions were obtained. 1) Through all the process, temperature was an important factor and the optimum was $60-80^{\circ}C$. 2) By first pass in the homogenizer, most oil droplets were finely dispersed. 3) In the homogenizing step the higher pressure results in the finer dispersion but as the pressure goes up, the differential efficiency of dispersion was decreased.

• 약학회지
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• 제37권1호
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• pp.66-75
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• 1993

Dental abrasive, dicalcium phosphate dehydrate (DCPD) was prepared and the several important factors affecting on the quality of toothpaste were investigated by means of set test, glycerine absorption, Coulter counter test, color difference, BET adsorption, mercury porosimetery, and rheogram comparing with two foreign DCPDs, MFO4 and Dentphos K. Sample DCPD was prepared by reaction between 85% H$_{3}$PO$_{4}$ and 15% milk of lime at $39^{\circ}C$ (pH6.5), and stabilized with TSPP and TMP. The physicochemical properties of Sample DCPD were obtained as follows: whiteness (98.99), average particle size (15.5 $\mu\textrm{m}$), pH (7.9), remainder particle weight (0.49w/w%), glycerine absorption value (64 ml), and set test (passed). N$_{2}$ adsorption curves (BET) of three kinds of DCPD showed non-porous type III isotherm. BET adsorption parameters of sample DCPD showed that surface area was 24.9 m$^{2}$/g, total pore volume 0.09 cm$^{3}$/g and average pore radius 72.0 $\AA$. The rheogram of the toothpaste containing each DCPD showed bulged plastic flow with yield vlaue and thixotropic behavior. These results meet standard requirements as abrasive standard, and suggested that synthesized sample DCPD could be used a dental abrasive such as a high quality grade in practice as foreign DCPDs.

• Journal of Pharmaceutical Investigation
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• 제16권2호
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• pp.68-71
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• 1986

Oil in water microemulsion which has many pharmaceutical applications was prepared and evaluated. As oil sources and emulsifier, two grades of oil and egg phosphatide were used, respectively. Vacuum high shear mixing and high pressure homogenizing were performed and in the homogenizing step, effect of the number of passes in the homogenizer on the stability of microemulsion was studied, using Coulter counter, photographic microscope and pH-meter. From above results, it was concluded that the stability of microemulsion made of refined soy-bean oil was better than that of food grade soybean oil and by five passes in the homogenizer at 6,000 psi, we could make stable microemulsion with average particle diameter below $1\;{\mu}m$, with no particle above $5\;{\mu}m$ and no significant change during 6 weeks stored.

• 대한기계학회논문집
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• 제15권2호
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• pp.618-629
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• 1991

The purpose of this experiment is to understand the distribution of coal particles inside CWM droplet which is believed to be a very important factor controlling the flame stability. CWM slurry is atomized by an air assisted twin fluid nozzle. An experimental rig is designed and fabricated. The mean size of coal particle distribution in CWM slurry, atomizing air pressure, coal particle loading in slurry and sampling position inside spray are main experimental variables. The atomized CWM droplets are sampled on the thin white layer of magnesium oxide by the emergency sampling shutter. The sampled coal particles on magnesium oxide layers are collected into test tubes and dispersed completely by Ultra-Sonicator. The size distribution of coal particles inside droplets are measured by Coulter Counter. The presence of coal particle inside the impressions of droplets on magnesium oxide layer are investigated by photo technique. There are quite many droplets which do not have any coal particles. Those are just water droplets, not CWM droplets. The population ratio of droplets without coal particles to toal number of droplets is strongly affected by the mean size of coal particle distribution in slurry and this ration becomes bigger number as the mean size of coal particles be larger. The size distribution of coal particles inside CWM droplets is not even and depends on the size of droplet. Experimental results show that the larger CWM droplets has droplets has bigger mean value of particle size distribution. This trend becomes more evident as the atomizing air pressure is raised and the mean size of coal particles in CWM slurry is bigger. That is, the distribution of coal particles inside CWM dropolets is very much affected by the atomizing air pressure and the mean size of pulverized coal particles in CWM slurry.

• 한국식품과학회지
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• 제22권4호
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• pp.369-372
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• 1990

두유에는 기름의 양이나 입도를 분석하는데 장해를 주는 대두단백질, 미세한 대두입자들이 공존하고 있어서 기존의 microscopic image analysis, coulter counter, 또는 Photo-analysis 등의 사용이 많은 문제점을 노출했다. 본 실험에서 Stokes 법칙을 응용하여, 중력장과 원심력장하에서 homogeneous suspension과 cumulative method를 이용하여 입도분포를 분석했다. 선정된 두유에서 기하학적 평균지름은 중력장하에서는 $0.33{\mu}m$ 표준편차 $1.73{\mu}m$이고, 원심력 장에서는 평균지름은 $0.31{\mu}m$, 표준편차는 $1.81{\mu}m$으로, 매우 유사한 결과를 얻었다. 균질압이 유화안정성에 크게 영향을 주는 인자이기 때문에 균질압을 변화했을 때, 균질압이 높을수록 평균입도는 작은 쪽으로 이동하였으며, 입자의 분산 형태는 평균지름을 중심으로 밀도 있게 분포하는 쪽으로 변화하여, 균질압이 기름 입도분포에 영향을 미쳐 유화 안정과 깊은 관계가 있는 것을 확인하였다.

• Journal of Preventive Medicine and Public Health
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• 제25권2호
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• pp.162-171
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• 1992

The hematologic effect by low-concentration and repeated exposure to mixed organic solvent remains obscure. This study was performed to evaluate the hematologic effect by mixed organic solvent exposure, especially on the type of anemia by mean corpuscular volume(MCV) and red blood cell distribution width(RDW). The subject were 64 organic solvent workers(male 4, female 60) and 78 general workers(male 18, female 60) who showed anemic tendency in worker's health examination which carried out by Pusan Paik Hospital from January to December, 1988. The author gained some hematologic findings(hemoglobin, hematocrit, RBC, WBC, MCV, MCHC, platelet count, ESR, RDW) from auto-analysis method by coulter counter S plus IV, and compared the type of anemia by MCV and RDW. In the pilot study for estimating the prevalence of anemia according to the type of b, the prevalence rate was higher in organic solvent workers than in public officials as 10.9% and 4.1% respectively. There were statistical significance in the value of hemoglobin, hematocrit, MCV, MCHC, platelet count, ESR, RDW between the two study groups with more severe anemic tendency in organic solvent workers. The type of anemia in organic solvent workers was microcytic and anisocytic with the mean value of $68.28{\pm}8.3fL$ of MCV and $19.1{\pm}4.0%$ of RDW.

• Journal of Biosystems Engineering
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• 제38권2호
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• pp.103-112
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• 2013

Background: The Korean government launched a project in 2008, where the amount of rice used as raw ingredient in rice-based foods in 2012 was planned to increase up to 10% (470,000 ton) of the total rice production through developing various new rice-based processed foods and their commercial manufacturing technology. Among the four major rice-based processed foods, rice cakes and noodles need rice flour as their main raw ingredient. Technology in rice flour utilization and manufacturing is far behind than the technology pertinent to wheat flour in many subject areas. Purpose: This review aims to provide information on rice flour utilization and manufacturing with some fundamental subjects in the area of size reduction. Results: A variety of food items including bread, noodle, cake, cookie, muffin, pre-mix, beverage, vinegar, surimi, and artificial meat have found rice flour as their raw ingredient. Rice bread made out of 100% rice flour has been developed and is now sold in retail stores. Various noodle products made from rice flour are also on the market. Issues on product definition and labeling regulation about rice flour content of the products were explored. Generalized grinding equations available in the literature were seldom used in practice; instead, it has been a general practice to develop empirical equations from test milling data. Introductory remarks on three popular particle size measurement methods (sieving, Coulter counter, light diffraction) were explained. Mathematical expressions frequently used to describe particle size distribution and to correlate cumulative quantity of particles with particle size were represented. Milling methods used in producing rice flour were described along with their advantages and disadvantages. Because of their profound effect on functional properties of the rice flour, four rice flour milling equipments used at both laboratory experiments and commercial manufacturing plants were discussed.