• Title/Summary/Keyword: alc

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An Experimental Study on the Mechanical Properties of Silica Fume and Fly Ash.Cement Composites (실리카흄 및 플라이애쉬.시멘트 복합체의 역학적 특성에 관한 실험적 연구)

  • 박승범;윤의식
    • Magazine of the Korea Concrete Institute
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    • v.6 no.5
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    • pp.158-170
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    • 1994
  • The results of an experimental study on the manufacture and the mechanical properties of carbon fiber rekforced silica fume . cement composites and light weight fly ash . cement composites are presented in this paper. 11s the test results show, the flexural strength, fracture toughness and ductility of CF reinforced silica fume . cement composites were remarkably increased by the increase of carbon fiber contents. And the workability of the fly ash . cement composites were improved, but the compressive and flexural strength and bulk specific gravity of them are decreased by increasing the ratio of fly ash to cement. And the compressive and flexural strength of the fly ash cement composites by cured under the hot water were improved than those by mositure cured. Also, the manufacturing process technology of lightweight fly ash . cement composites in replacement of general autoclaved lightweight concrete was developed and its optimum mix proportions were proposed.

The Analysis of Geriatric Nutritional Risk Index (GNRI) for Nutritional Assessment and Health Care in Elderly Women (여자노인의 영양상태 평가 및 건강관리를 위한 Nutritional Risk Index (NRI) 비교 분석)

  • Yang, Eun-Ju
    • Journal of Nutrition and Health
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    • v.42 no.3
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    • pp.234-245
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    • 2009
  • Nutritional assessment for the elderly can identify health status and morbidity. However, development of Nutritional Risk Index (NRI) remains limited for elderly because of difficulties in understanding physiological mechanism of elderly. This study was performed to analyze and develop Nutritional Risk Index for Korean elderly Women (Geriatric Nutritional Risk Index, GNRI). Based on literature review, factors for NRI were identified and indices were assessed by a cross-sectional survey. The survey involved Korean elderly women (${\geq}$60, n = 94) in Gwangju area, and sociodemographics, lifestyle characteristics, health conditions, dietary intakes based on 24h- recall, anthropometric measures (wt, ht, BMI, waist, hip, WHR, body protein, body fat, abdominal fat, and triceps skinfold thickness), and clinical biochemistry parameters (systolic blood pressure, diastolic blood pressure, cholesterol, HDL-cholesterol, triglyceride, total protein, albumin, prealbumin, hemoglobin, hematocrit, fasting blood glucose, HbAlc, ferritin, Zn, Ca, Na, K, Vit E, Vit $B_{12}$, folate, C-reactive protein) were examined relation to nutritional risk index. Based on literature review and data analyses, three NRIs were categorized (NRI I, NRI II, NRI III) and used for further analysis. NRI I was related to having metabolic syndrome, NRI II was related to serum albumin and body weight, and NRI III was related to food habit and health concerns. Abdominal fat (%) of elderly was correlated with each NRIs. NRI II was correlated with nutritional deficiency and higher tendency of inflammatory response, and NRI III was correlated with nutritional status which tend to be lower on aging (protein, folate, Vit $B_{12}$). NRI can serve as a useful tools in assessing health risk and nutritional status. Some modification of items in NRI and validity study are need to apply to Korean elderly.

Behavior characteristics of Light-Weight Pavement Using Centrifuge Test (원심모형실험을 이용한 경량포장체의 거동특성)

  • Kim, Seong-Kyum;Lee, Kwan-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.10
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    • pp.5176-5183
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    • 2013
  • In general, Korean Lightweight Concrete used Heat insulating material for building and filler for civil construction, backfill material for tunnel, office floor fillers, lightweight blocks and so on. These expand the range of use ALC(autoclaved lightweight concrete) on the soft-ground at regular intervals during road construction by installing piles used as substrates for the process is under study. In this study, behavior characteristics on the soft-ground of pavement analysis was used to test the geo-Centrifuge. Prototype pavement reduced to 1/30 slab form of the composition as kaolinite model tests were conducted in the soft ground. Pile Arrangement (having 36 component pile with an array of $3{\times}12$) was used to group of piles. Tests of gravity 30 level the centrifugal force acting Light-weight pavement models. Based on the Prototype pavement of the behavior characteristics of pavement behavior characteristics were estimated. FMA analysis of the 10 times as big 39.4kg (actual load 35 ton) of the lateral load is applied to the case 7.8mm (actual behavior 23.4mm) behavior was fine.

Studies on the Constituents of Korean Edible Oils and Fats -Part 3. Studies on the oil soluble constituents of sunflower seed- (한국산(韓國産) 식물식용유지(植物食用油脂)의 성분(成分)에 관(關)한 연구(硏究) -제3보(第3報) 해바라기 종자(種子)의 유성성분(油性成分)에 대하여-)

  • Choi, Kee-Young;Ko, Young-Su
    • Journal of Nutrition and Health
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    • v.12 no.2
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    • pp.75-85
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    • 1979
  • The Korean origin sunflower (Helianthus Annus Linn.) seed of netural lipid were analysed by thinchrography, High performance liquid chromatography, preparative Thinlayer and Gas liquid chromatography. 1) The seed oil triglyceride components were conveniently separated based on their degree of unsaturation by employing the chromatography on silica gel sintered rod impregnated with 12.5% silver nitrate. Sunflower seed oil was composed of triglyceride, especially trilinolein 57. 74% triolein 25.28%, tripalmitin 7 55% ana tristearin 9.43% by a thinctrography. 2) The fatty acid compositions of seed oil have been determined by a high performance liquid chromatographic analysis using a ALC/GPC 244 type from Waters Association (Japan) with ${\mu}$ Bondapak FFAA column. It contained stearic acid 8.59%, oleic acid 27. 19%, palmitic acid 7.50% and linoleic acid 56.72% respectively. 3) The composition of sterols were determined by a preparative Thinlayer and Gas liquid chromatographic analysis. It was noted that sitosterol was the major sterol in the Korean sunflower seed. The results showed that contents of sterols were cholesterol trace, campesterol $13_.^{22\sim}13.9%$, stigmasterol $13.8{\sim}14.1%$, If, sitosterol $58.4{\sim}60.7%$, ${\vartriangle}^7$-stigmastenol $10.2{\sim}10.5%$ and ${\vartriangle}^{7,24(25)}$-stigmastenol $3.6{\sim}3.8%$ by method of planimetry and triangulation.

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Antioxidant vitamins and Lipid Peroxidation in Patients with Type 1 Diabetes Mellitus

  • Lee, Yeon-Kyung;Jang, Hyun-Sook;Kim, Bo-Wan;Kim, Heung-Sik;Kwon, Chong-Suk
    • Preventive Nutrition and Food Science
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    • v.4 no.1
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    • pp.57-61
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    • 1999
  • It has been postulated that oxidative stress may be increased and antioxidant defenses reduced in diabetes patients. Twenty-four patients with type 1 diabetes melitus (DM) (12.8$\pm$1.7 years) and 24 nondiabetics (12.5$\pm$2.1 years) were included in this study. Serum total cholesterol and LDL -cholesterol levels were significantly higher in diabetic than in nondiabetic control subjects, but serum levels of triglyceride , retinol , tocopherol, and $\beta$-carotene were significantly lower. Both $\beta$carotene and tocopherol levels inversely correlated with HbAlc, suggesting perhaps that low serum antioxidant level enhance theglycosylation of hemoglobin. Subjects with type 1 DM had lipid peroxide levels similar to those of nondiabetics control subjects, suggesting that per-oxdation of circulating lipid is not increased in uncomplicated diabeteics. The correlation between antioxidants and serum lipids were as follows ; retinol and LDL (r--0.36, p=0.019) ; retinol and total cholesterol(r=-0.35, p=0.020), tocopherol and LDL(r=-0.47, p=0.002) ; tocopherol and cholesterol (r=-0.49, p=0.001) ; $\beta$-carotene and LDL (r=-0.51, p=0.001). Overall , the results of this study were that serum lipid peroxide in patients with type 1 DM was similar to those of control subjects and antioxidants such as retinol, tocopherol and $\beta$-carotene were lower than those of nondiabetic cotnrol subjects, and negatively correlated with serum total cholesterol and LDL-cholesterol.

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Eligibility of Fluoride Ion as A Tracer of Wastewaters and Distribution of Fluoride in Jinhae Bay (해수오염원추적자로서의 플루오르화물이온 및 진해만의 플루오르화물이온농도분포)

  • Won, Jong Hun;Park, Kil Soon
    • 한국해양학회지
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    • v.8 no.1
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    • pp.9-21
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    • 1973
  • When industrial wastewater containing fluoride runs into the ocean, approximately 0.1ppm of F$\^$-/ will react with seawater and will be eventually lost, and the remaining F$\^$-/ can be determined withe the ALC. Therefore F$\^$-/ is eligible to be used as a tracer of pollutant which contains fluoride. Determination of F$\^$-/ in the seawater with the Dotite reagent, Alfusone, has been made by the following method: To 10 ml of water sample, 1 ml of buffer solution (pH=4.0), 8 ml of acetone, and 1ml of 10% Alfusone were added and diluted to 25ml with distilled water. After 20 minutes the absorbance at 620 nm against a reagent blank was measured. The distributions of F$\^$-/ in Jinhae Bay has been made on the basis of water samples collected from 103 different sampling stations occupied in Jinhae Bay. The water samplings, three in the spring tide and two in the neap tide, were taken from surface layer during the flood and ebb tide periods respectively. The average concentration of F$\^$-/ in the bay, except the area to which the wastewater runs off from the Chemical plant, was 1.45 ppm(1.07-6.33ppm), and that of F$\^$-/ in the plant effluent was 330ppm, occasionally up to 562 ppm. Thus high levels of F$\^$-/ in the bay are strongly correlated to the amount of effluent from the plant, and waters of Jinhae Bay contains at least 0.13% of the plant effluent.

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A Study on Advanced Satellite Uplink Rain Attenuation Compensation using Digital Transponder of Next Military Satellite (차기 군위성체계의 디지털 위성중계기를 이용한 상향링크 강우감쇠에 대한 향상된 보상방안 연구)

  • Kim, Jung-Ho;Lee, Sue-Hyun;Kim, Bong-Su;Lee, Chang-Young;Song, Young-Joong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.11B
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    • pp.1696-1703
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    • 2010
  • Increased demand for military satellite communications system and due to the depletion of resources of existing satellite communications frequencies, Ka-band and EHF-band satellite communication systems is growing demand for development. As a result, the study of rain attenuation mitigation for Ka/EHF-band frequencies has been achieved. The method to compensate rain attenuation on Ka-band(20/30) using the signal power measurement function in Digital Transponder of Next Military Satellite has been proposed in this paper. This method is more effective than generally used method by Beacon and UPC(uplink power control) in giving the precise rain attenuation measurement and correction.

Electrochemical Reduction of Thionyl Chloride by Tetradentate Schiff Base Transition Metal(II) Complexes : Catalytic Effects (네자리 Schiff Base 전이금속(II) 착물들에 의한 SOCl$_2$의 전기화학적 환원 : 촉매 효과)

  • Woo-Seong Kim;Yong-Kook Choi;Chan-Young Kim;Ki-Hyung Chjo;Jong-Soon Kim
    • Journal of the Korean Chemical Society
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    • v.37 no.8
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    • pp.702-710
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    • 1993
  • Electrochemical reduction of thionyl chloride has been carried out at glassy carbon and molybdenum electrodes, the surface of which is modified by binuclear tetradentate schiff base Co(II), Ni(II),Cu(II) and Fe(II) complexes. The catalyst molecules of transition metal(II) complexes were adsorbed on the electrode surface and reduced thionyl chloride resulting in a generation of oxidized catalyst molecules. There was an optimum concentration for each catalyst compound. The catalytic effects of SOCl$_2$ reduction were larger on glassy carbon electrodes compared to molybdenum electrodes and enhancements in reduction current of up to 120${\%}$ at the glassy carbon electrodes. The reduction currents of thionyl chloride were increased and the reduction potentials were shifted to the negative potential when scan rates became faster. The reduction of thionyl chloride was proceed to diffusion controlled reaction.

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Controlled Expression and Secretion of Aspergillus oryzae Alkaline Protease in Aspergillus nidulans

  • Kim, Eun-Ah;Lee, Jeong-Goo;Whang, Mi-Kyung;Park, Hee-Moon;Kim, Jeong-Yoon;Chae, Suhn-Kee;Maeng, Pil-Jae
    • Journal of Microbiology
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    • v.39 no.2
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    • pp.95-101
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    • 2001
  • In an effort to develop an efficient expression and secretion system for heterologous proteins in Aspergilius nidulans, the PCR-amplified coding sequence for alkaline pretense (AlpA) of A. oryzae was cloned into a fungal expression vector downstream of A. nidulans aicA (alcohol dehydrogenase) promoter to yield pRAAlp. Transformation of A. nidulans with pRAAlp gave stable transformants harboring various copy numbers (3 to 10) of integrated alpA gene, from among which 6 representatives were selected. On a medium containing 0.8% ammonium sulfate that represses the expression of the host's own pretense, the alcA prumoter-controlled AlpA expression was strongly induced by threonine but repressed by glucose. The level of AlpA secretion was highest (approximately 666 mU/ml) in transformant ALP6 containing the largest copy number integrated alpA. However, the level of AlpA secretion was not necessarily proportional to the copy numbers of the integrated alpA genes. The N-terminal sequence or the secreted mature AlpA was determined to be Gly-Leu-Thr-Thr-Gln-Lys-Ser and its molecular mass to be approximately 34 kDa, indicating that AlpA is properly processed by the removal of 121 N-terminal amino acids.

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Effect of Fiber Addition for Improving the Properties of Lightweight Foamed Concrete (경량 기포콘크리트의 성능향상에 대한 섬유혼입의 영향)

  • Lee, Kyung-Ho;Yang, Keun-Hyeok
    • Journal of the Korea Institute of Building Construction
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    • v.15 no.4
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    • pp.383-389
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    • 2015
  • The objective of this study is to develop mixture proportioning approach of crack controlled lightweight foamed concrete without using high-pressure steam curing processes, as an alternative to autoclaved lightweight concrete blocks (class 0.6 specified in KS). To control thermal cracks owing to hydration heat of cementitious materials, 30% ground granulated blast-furnace slag (GGBS) was used as a partial replacement of ordinary portland cement (OPC). Furthermore, polyvinyl alcohol (PVA) and polyamid (PA) fibers were added to improve the crack resistance of foamed concrete. The use of 30% GGBS reduced the peak value of hydration production rate measured from isothermal tests by 28% and the peak temperature of foamed concrete measured from semi-adiabatic hydration tests by 9%. Considering the compressive strength development, internal void structure, and flexural strength of the lightweight foamed concrete, the optimum addition amount of PVA or PA fibers could be recommended to be $0.6kg/m^3$, although PA fiber slightly preferred to PVA fiber in enhancing the flexural strength of foamed concrete.