• Journal of the Korean Society of Safety
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• v.18 no.3
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• pp.81-87
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• 2003

Latex polymers are widely used for adhesive, binder, paint etc. Especially the PVAc(Polyvinyl acetate) latex which manufactured by vinyl acetate and vinyl alcohol as protective colloid is a useful environmentally friendly adhesive. To increase useful property of PVAc latex, this study was carried out for checking thermal characteristics and physical condition of PVAc latex by DSC, FT-IR, Pyrolyzer GC-MS. The activation energies of thermal decomposition for 40, 48, 56, 64% solid content of PVAc latex were found as 28.1-36.0kcal/mol by Kissinger's method and 17.2-22.0kcal/mol by DSC method. Actually, reasonable solid content could be consiered as 56% because of activation energy and adhesive characteristics. According to the effect of protective colloid for 4, 10, 15, 20wt%, the activation energy shows same tendency to both method and in case of l5wt% has been found as the highest activation energy. The mechanism of thermal decomposition was mainly estimated by main chain scission, not by side group on FT-IR analysis. Main component of Pyrolzer GC-MS result were consisted of $CH_3COOH$, $CH_3$, $H_2O$ and light gases(CO, $CO_2$, $CH_4$ etc).

• Nuclear Medicine and Molecular Imaging
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• v.40 no.2
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• pp.127-131
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• 2006

Radiosynovectomy has been used as an effective treatment in patients with resistant synovitis after failure of long-term medication and intraarticular steroid injection. Although $^{90}Y$ silicate/citrate, $^{186}Re$ sulfide, and $^{169}Er$ citrate were approved in Europe for the appropriate radiopharmaceuticals for radiosynovectomy other radionuclides such as $^{32}P$-chromic phosphate, $^{165}Dy$-ferric hydroxide macroaggregate, $^{188}Rh$-microspheres, $^{153}Sm-particulate, and $^{166}Ho$-ferric hydroxide macroaggregate have been used in many countries. Reported success rates range from 40% to 90% for the different joints and underlying disease. In Korea, $^{188}Re$-tin-colloid and $^{166}Ho$-chitosan complex are now using as the major radionuclides in radiosynovectomy with good clinical results. A study on radiation synovectomy using $^{188}Re$-tin-colloid for patients with Korean rheumatoid arthritis shows the treatment resulted in the improvement of arthritis and well tolerated in our study, the radiosynovectomy with $^{166}Ho$-chitosan complex in 53 hemophilic patients markedly decreased intra-articular bleeding frequency and need for coagulation factor. This review inculdes general priciples in the application of radiosynovectomy and the clinical experience in Korea.

• Korean Journal of Poultry Science
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• v.29 no.1
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• pp.7-12
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• 2002

This study was conducted to investigate the effects of feeding germanium colloid(GC) on the egg quality and immune response in 1aying hens. One hundred forty four layers, 32-wk-old ISA Brown, were used in a 40-d experimental assay with a 7-d adjustment Period. Dietary treatments included 1) control (basal diet; CON), 2) 0.5ppm GC (basal diet + 0.Sppm germanium), 3) 1.0ppm GC (basal diet + 1.0 ppm germanium) . For overall Period, hen-day e99 Production tended to be increased as the concentration of GC in the diets was increased with significant difference (linear effect, p<0.01) . Laying hens fed 0.5ppm GC diet were significantly (P<0.01) lower in egg shell breaking strength than laying hens fed CON or 1.0 ppm GC diets. Egg shell thickness and yolk color were not influenced by GC supplementation. Laying hens fed 1.0ppm GC diet were h19her in egg yolk Index than laying hens fed CON and 0.5ppm GC diets with significant difference (quadratic effect, p<0.02) . As adding level of germanium colloid increased in the diets, the total serum cholesterol and triglyceride tended to be decreased. However, the effect of GC supplementation did not show significant in the levers of total serum cholesterol and triglyceride. Also, HDL- and LDL+VLDL-cholesterol in serum were not statistically different among the treatments. Red blood cell and white blood cell count in blood tended to be increased as the concentration of GC in the diets was increased with significant difference (P<0.01) . Hematocrit concentration in blood was successfully Increased by supplementation of GC (P<0.01) . In conclusion, although egg quality was not influenced by GC supplementation, supplementing GC Improved Immune status in laying hens.

• Journal of Biosystems Engineering
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• v.36 no.5
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• pp.342-347
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• 2011

The effect of SNC(silver nano colloid) on the emission reduction of odors such as ammonia ($NH_3$), hydrogen sulfide ($H_2S$), and methane ($CH_4$) from swine excreta was studied. Silver has been used as an universal antibiotic substance and can reduce the emission of some gases by sterilizing action. Therefore, an apparatus which produces SNC was developed and was conducted its performance test. Also, the SNC made by the apparatus was applied to swine excreta sampled from a piggery in oder to find the effect on the reduction of odor emission. An electrolysis apparatus was developed to produce SNC and its capacity was 0.024 ppm/$hr{\cdot}L$. The effects of SNC on the reduction of odor emission from swine excreta were tested for bad smell gases of ammonia ($NH_3$), hydrogen sulfide ($H_2S$) and methane ($CH_4$). For ammonia gas, factorial experiments were conducted to find the effects of concentration and application rate of SNC. The test results for the different concentrations of 20 ppm, 50 ppm, and 100 ppm showed that the more concentration of SNC was increased, the more emission reduction of ammonia gas increased. From the test results about the effect of application rate, the more SNC was applied, the more emission reduction of $NH_3$ increased. In order to reduce the concentration of $NH_3$ below 5 ppm, SNC of 50 ppm is recommended to be applied at an interval of 6 hours, and is mixed with swine excreta in the volumetric ratio of 4:1. For hydrogen sulfide gas, the concentration was decreased as time went by and was reduced rapidly in the first stage of the tests for all applied concentrations of SNC (20 ppm, 50 ppm, and 100 ppm). Especially, when 100 ml of SNC with 100 ppm was applied, emission of hydrogen sulfide gas was reduced rapidly during early 4 hours after the application of SNC. And, concentration of hydrogen sulfide gas was maintained below 20 ppm after 12 hours. For methane gas, t-test showed that there was no significance on the effect of its application for all applied concentrations of SNC. Therefore, it was concluded that the application of SNC on swine excreta had no effect on the emission reduction of $CH_4$.

• Journal of Chest Surgery
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• v.27 no.3
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• pp.177-186
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• 1994

Pentastarch is a hydroxyethyl starch similar to hetastarch, but lower average molecular weight and fewer hydroxyethyl groups which result in enhanced enzymatic hydrolysis and faster renal elimination.This report was performed to compare the clinical efficacy and safety of 10 % pentastarch[Pentaspan , group I] for plasma volume expansion after open heart surgery with that of 5% albumin[Plasmanate, group II]. There were no statistically significant differences between the group I [n=18] and group II [n:19] in the preoperative parameters [age, sex, body weight] and operative parameters[bypass time, aorta cross clamping time]. During the first 24 hours after arrival of the patient in the surgical intensive care unit, colloid solution [500--1000 ml] was infused to maintain left atrial pressure of more than 8 mmHg, or cardiac index of 2.0 L/min/M2 of more. In results, there were 3 complications of hypotension immediately after infusion of 5 % albumin solution and 2 among the 3 patients were excluded for the study. However there was no complication after infusion of 10 % pentastarch solution. Hemodynamic responses to infusion was similar for both groups, although in group I a greater increase in both left atrial pressure[mean 1.8 versus 0.7 mmHg, p< 0.05] and right atrial pressure [mean 2.2 versus 1.7 mmHg, p < 0.05] was observed during infusion of the first 500 ml. There were no significant differences in any of the measured respiratory parameters[PaO2, intrapulmonary shunt, and effective lung compliance]. Homodilution with colloid significantly reduced hemoglobin [mean 1.2 versus 0.8 gm/dl], and serum protein and albumin level[total protein;4.8$\pm$ 0.5 versus 5.2 $\pm$0.5 gm/dl, p < 0.05: albumin: 3.2 $\pm$0.4 versus 3.6 $\pm$0.6 gm/dl, p < 0.05] by 6:00 AM on 1 day postoperatively, however there were no significant differences on 7 day postoperatively. The mean serum colloid osmotic pressure and osmolarity was similar in both group.There were no abnormal findings of liver function and kidney function in all the patients. There were no significant between-group differences in bleeding time, platelets, prothrombin time, activated partial thromboplastin time and amount of chest tube output measured on 1st and 7th postoperative day. These findings demonstrated that 10% pentastarch is more effective and safe for plasma volume expension than 5 % albumin solution with no adverse effects on coagulation. Also 10 % pentastarch is less expensive than 5 % albumin and it would appeare to be a reasonable first choice for plasma volume expansion.

• The Korean Journal of Nuclear Medicine
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• v.21 no.1
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• pp.9-16
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• 1987

It is well-known that hepatic scintigraphv have been found to be less sensitive and specific in the detection of the diffuse hepatocellular diseases than that of the space-occupying lesions. To obtain the higher diagnostic specificity and sensitivity, we, using the computer quantitation, have attempted to analyze hepatic and extrahepatic $^{99m}Tc-tin$ colloid uptake patterns in various diffuse hepatocellular diseases retrospectively. The studied groups consisted of 116 cases of normal, 67 cases of acute hepatitis, 112 cases of chronic hepatitis, 61 cases of liver cirrhosis, 47 cases of fatty liver, 12 cases of hepatoma and 9 cases of metastasis, making total 424 cases. Scintigraphic imagings were obtained in the anterior, right lateral and posterior projections using high-resolution collimation, and simultaneously these gamma data were acquisited into the computer system. Both large region of interest (ROI) using light pen and ROI computer program were placed over right lobe, left lobe of liver, spleen and cardiac blood pool. Total counts in ROI were divided by the number of pixels in the ROI, and mean count rate per pixels calculated. Mean right-lobe counts were divded by mean-left lobe counts to determine right-to-left hepatic lobe ratio and mean spleen counts were divided by mean liver counts to determine spleen to liver ratio. The results were as follows. 1) Of 424 cases, 292 were male and 132 were female. The majority of age distribution was in $30\sim49$ (54.5%). 2) Inter-observer between two independant operators and inter-method between drawing by light-pen and ROI computer program variations were not significant. 3) The uptake count values (per pixel) determined at each area in normal group were $106.53{\pm}18.35$ in right lobe, $79.00{\pm}13.82$ in left lobe, $17.52{\pm}8.31$ in spleen and $8.09{\pm}3.43$ in cardiac blood pool. 4) In liver cirrhosis, right lobe uptake was decreased but spleen and cardiac blood pool uptakes were increased (p<0.01). 5) Right-to-left hepatic lobe uptake ratio was $1.37{\pm}0.24$ in normal group and significantly low in chronic hepatitis, liver cirrhosis and fatty liver, and more or less low in acute hepatitis. 6) Spleen-to-right hepatic lobe uptake ratio was $0.17{\pm}0.09$ in normal group and high in chronic hepatitis and liver cirrhosis. 7) The computer-quantitation of hepatic and extrahepatic uptake patterns thought to be sensitive and useful method in the interpretation of liver scintigram.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.239-247
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• 2005

In this study, an experimental study on the sorption properties of uranium(VI) onto bentonite colloids generated from a domestic calcium bentonite (called as Gyeongju bentonite). Gyeongju bentonite has been considered as a potential candidate buffer material in the Korean disposal concept for high-level radioactive wastes. The size and concentration of the bentonite colloids used in the sorption experiment were measured by a filtration method. The result showed that the concentration of the synthesized bentonite colloid suspension was 5100ppm and the size of the most of bentonite colloids(over $98\%$) was in the range of 200-450nm in diameter. The amount of uranium lost by the sorption onto bottle walls, by precipitation, and by ultrafiltration or colloid formation was analyzed by carrying out some blank tests. The loss of uranium by the ultrafiltration was significant in the lower ionic strength(i.e., in the case of 0.001M $NaClO_4$) due to the cationic sorption effect onto the ultrafilter by a surface charge reversion. The distribution coefficient (or pseudo-colloid formation constant) for the sorption of uranium(VI) onto bentonite colloids was $10^4^{\sim}10^6$ mL/g depending upon pH and the distribution coefficient was highest in the neutral pH around 6.5.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1996.06b
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• pp.259-279
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• 1996

최근 정보·전자산업의 발전으로 고 신뢰성 전자재료에 대한 수요가 증대되고 있으며 이러한 첨단산업의 기반의 될 신소재 중 전자세라믹스가 차지하는 비중이 그 대부분을 차지하고 있으며 이에 대한 수요와 기대가 점점 커지고 있다. 이러한 전자세라믹스는 유전재료, 자성재료, 압전재료, 도전성 재료 등으로 나뉘게 된다. 어떠한 분류에 들어가든 그 조성은 금속의 산화물 형태가 일반적이며 미세한 분말의 성형체를 소결(sintering) 함으로써 최종제품으로 완성된다. 이러한 전잣라믹스가 최근 요구되는 고 신뢰성, 고 밀도화를 달성하기 위해선 원료 분말 제조단계부터 제어가 필요하다. 원료분말의 균일·균질성과 그 입도는 소결특성 뿐만아니라 전기적 특성에도 큰 영향을 미치기 때문이다. 세라믹스의 분말제조 방법 중 일반적으로 사용되는 방법으로는 고상 산화물을 혼합하여 하소(calcination)한 후 분쇄하는 '고상합성법'과 금속의 염 또는 alkoxide 용액을 이용하여 화학적으로 제조하는 '습식 화학적 합성법'이 있다. 고상합성법은 합성온도가 높고 기계적 분쇄와 혼합에 의존하므로 균일·균질성이 떨어지고 분말크기를 1㎛ 이하로 만들기 힘들다. 반면에 습식화학적 합성법은 기계적인 분쇄와 혼합에선 얻을 수 없는 원자 혹은 분자단위의 균일한 혼합과 submicron 이하의 미세한 분말을 얻을 수 있다. 따라서 이러한 습식 화학적 합성으로 얻은 분말을 사용하면 미세한 입자의 특성으로 인해 소결온도를 낮출 수 있으며 균일한 미세구조와 균질한 조성을 갖게되어 기계적·전기적 물성증진도 가져올 수 있게 된다. 습식 화학적 분말합성법은 전술하였듯이 alkoxide의 가수분해를 이용하는 sol-gel 법과 금속의 염(salt) 용액을 이용하여, 화학적으로 화합물 침전을 얻거나 또는 공침전물(coprecipitate) 형태의 분말을 얻는, 침전법으로 나뉠 수 있다. 침전법의 근본원리는 pH 및 pCO3 등에 따른 이온종의 용해도 차이를 이용하는 것으로써 각 이온종에 따른 solubility product(ksp)를 이용하여 설명된다. 본 연구에서는 침전법을 사용한 Ba-, Pb-계 전자세라믹스의 분말합성에 대한 이론적 고찰과 공정개발 및 실험을 통한 물성증진 효과에 대해 알아보았다. 본 실험상의 전자세라믹스 조성은 강유전체, 세라믹반도체, 압효과에 대해 알아보았다. 본 실험상의 전자세라믹스 조성은 강유전체, 세라믹 반도체, 압전재료로 널리 사용되는 BaTiO3, PZT(PbZrO3-PbTiO3)와 수직 자기기록매체로 큰 가능성이 있으며 hard ferrite로 널리쓰이는 Ba-feerite(BaFe12O19)로써 수산화물 형태의 침전에 대한 기구(mechanism)와 물성에 대해 살펴보았다. 이러한 침전법에 의한 분말합성 과정에는 소결체의 물성에 영향을 미치는 pH 조절제나 원료에서 혼입될 수 있는 Na+, K+, Cl-, SO4- 등의 제거(washing 혹은 filtering)가 필수적이다. 그러나 침전법에서 얻게 되는 분말은 매우 미세하여 colloid를 형성하게 되며, 이러한 colloid 상태의 미세한 침전입자가 filtering media에 끼이게 되어 견고하면서도 상당한 부피를 가지는 filter cake을 형성하기 때문에 filtering에 많은 시간과 다량의 filtering agent (본 실험의 경우엔 증류수)가 필요하게 된다. 따라서 이러한 문제점을 해결하기 위하여 colloid 상태의 침전물을 얼렸다 녹이는 freezing process를 개발, 적용하여 그 원리 및 효과, 그로인한 분말형태를 관찰하여 보았다.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.6
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• pp.327-331
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• 2006

Purpose: Aspiration scintigraphy is a procedure of nuclear imaging to evaluate aspiration and of quantifying the amount of aspirate. The ultimate goal of our study is to define the correlation between aspiration and aspiration pneumonia by aspiration scintigraphy and this is a preliminary report of its trial. Materials and methods: Ten patients with positive findings by videofluoroscopy were selected. The patients ingested semi-solid food containing Tc-99m tin colloid 92.5 MBq (2.5 mCi) and images were acquired immediately after the ingestion and 3 hrs later. A fraction of aspiration to the ingested was calculated using an equation with a decay correction. Results: Five patients were interpreted positive by aspiration scintigraphy. Four patients were positive at initial images and the fractions of aspiration were 0.11%, 0.11%, 0.81%, and 0.11%. The one patient who was shown aspirated at both images had initial 5.82% and delayed 2.26%. Conclusion: Aspiration scintigraphy enables us to localize the aspiration at any desired time of the test and to quantify its amount. Follow-up studies are warranted.

• Proceedings of the Membrane Society of Korea Conference
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• 1996.04a
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• pp.1-4
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• 1996

유화제의 물리화학적인 성질을 이용하여 O/W와 W/O에멀젼을 제조하는 방법(예:PIT method, D-phase method)은 이제까지 많은 연구가 진행되어 왔으며, colloid mill, homogenizer, ultrasonic emulsifier와 같은 유화장치도 지속적으로 개발 및 개선되고 있다. 하지만 이들 방법은 공정의 정확한 조절이 어려우며, 제조된 에멀젼의 입자크기 분포가 다분산적(polydispersed)이라는 단점을 가지고 있다. 이를 극복하기 위한 방법으로 1980년대 중반에 일본에서 처음으로 개발된 막유화법이 있다. 이 기술은 pouous glass membrane 가운데 기공크기(pore size)가 균일한 SPG(Shirasu Porous Glass)막을 사용하여 균일한 입자분포를 가지는 에멀젼을 제조하는 것이다. 한편 막유화에 사용되는 막이 갖추어야 할 조건은 다음과 같다.