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THERMAL CHANGE AND MICROHARDNESS IN CURING COMPOSITE RESIN ACCORDING TO VARIOUS CURING LIGHT SYSTEM (광중합기에 따른 복합레진 중합시 온도 변화와 미세경도에 관한 연구)

  • Lee, Dong-Jin;Kim, Dae-Eop;Yang, Yong-Sook;Lee, Kwang-Hee
    • THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY
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    • v.31 no.3
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    • pp.391-399
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    • 2004
  • The purpose of this study was to compare curing efficiency of newly developed curing units to traditional halogen curing unit by measuring thermal change and surface microhardness according to curing light system. Materials and mathods : The types of curing units were traditional low intensity halogen light(Optilux 360), plasma arc light(Flipo), low heat plasma arc light(Aurys), low intensity LED(Starlight), and high intensity LED(Freelight2). Temperature at the tip of light guide was measured by a digital thermometer using K-type thermocouple. And after resin was filled to 2, 3, 4mm teflon mold, bottom temperature measured during curing. After 24 hours, microhardness of top surface and bottom surface of each resin specimen were measured. Results : The result of this study can be summarized as follows, 1. As measuring temperature of curing unit tips, Flipo is the highest as $52.4^{\circ}C,\;Freelight2(37.86^{\circ}C),\;Optilux360(32.68^{\circ}C),\;Aurys(32.34^{\circ}C),\;and\;Starlight(26.14^{\circ}C)$ were followed. 2. Flipo and Freelight2 were the highest similarly and Optilux360 and Aurys were similarly next and Starlight was lowest in temperature of bottom surface of resin mold. 3. Microhardness of top surface were generally similar, and Aurys was relatively low. 4. Optilux 360 and Freelight2 were the highest, and Flipo, Starlight, and Aurys were followed in microhardness of bottom surface. Conclusions : The results suggest that careful use of Flipo and Freelight2 might be able to cure greater depth of resin composite and do not cause thermal problems than other curing units.

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The Consideration of Bolus Effects of Games Attached on Lesion area (환부 부착용 거즈의 Bolus Effect에 관할 고찰)

  • Park JuYoung;Ju SangKyu;Park YoungChul;Han YoungYi;Shin EunHyuk;Park YongHwan
    • The Journal of Korean Society for Radiation Therapy
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    • v.16 no.1
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    • pp.51-56
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    • 2004
  • The aim of this study is to evaluate the effect of skin dose and PDD by using wounds protecting gauzes or Vaselinespread gauzes. And it was studied that the possibility to substitute custom bolus into gauzes. 4MV photon (CL600C, varian, US), Polystyrene Phantom (30(W) X30(L) X 30(H)) with Markus chamber(PTW, US) were used for dose measurement. This study was distinguished natural gauzes and spread over Vaseline gauzes. We gave variety to the gauze thickness at 5, 10 and 15 sheets respectively. For comparison between using bolus and not that, we had used 1.0 cm thickness bolus so that analyzed surface dose and PDD at the same conditions above mentioned. When maximum point was defined as reference point, surface dose was measured as $35\%$ in open beam. When the gauzes were attached to surface as 5, 10 and 15 sheets, surface dose were increased as 69, 80 and $91\%$ respectively according to thickness of gauzes. When spread over Vaseline gauzes were attached to surface as 5, 10 and 15 sheets, surface dose were increased respectively as 98, 100 and $98\%$ according to thickness of gauzes. Also when 0.5 cm bolus and 5 sheets gauzes were composed, surface dose was measured as $98\%$. The gauzes that were attached to skin surface in radiation therapy had been scattering material and contributed increasing surface dose without variation of percentage depth dose. However, if we want to delivery much dose to skin surface then we have to apply many sheets of gauzes to skin surface. Although we get easy that result by bolus or spread over Vaseline gauzes, we have to revise percentage depth dose at calculation. Therefore, if we find pertinent conditions based on measured data that are considered skin dose and patient setup efficiency, to replace custom bolus with gauzes will be helpful to efficient treatment.

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Ecosysteme de I′Etang de Berre (Mediterranee nord-occidentale) : Caracteres Generales Physiques, Chimiques et Biologiques

  • Kim, Ki-Tai
    • Korean Journal of Environmental Biology
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    • v.22 no.2
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    • pp.247-258
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    • 2004
  • Climatological, hydrological and planktonical research studies, measurements of primary production and photosynthetic efficiency from December 1976 to December 1978 have been carried out in two brackish lakes: Lake Etang de Berre and Lake Etang de Vaine located in the French Mediterranean coast, in the region of Carry-le-Rouet located on the north-west Mediterranean near Marseilles, and in fresh water inflows from 4 Rivers (Touloubre, Durance, Arc, Durancole) to Lake Etang de Berre. Physico-chemical parameters were measured for this study: water temperature, salinity, density, pH, alcalinity, dissolved oxygen (% saturation), phosphate, nitrate, nitrite, silicate etc. Diverse biological parameters were also studied: photosynthetic pigments, phaeopigments, specific composition and biomass of phytoplankton, primary pelagic production etc. Climatical factors were studied: air-temperature, solar-radiation, evaporation, direction (including strength) of winds, precipitation and freshwater volume of the four rivers. The changes in Lake ‘Etang de Berre’ ecosystem depend on the quality of the water in the Durance River, and on the effects of seawater near the entrance of the Caronte Canal. The water quality of the lake varies horizontally and vertically as a result of atmospheric phenomena, maritime currents and tides. The distribution of water temperatures is generally heterogeneous. Southeasterly winds and the Northeasterly Mistral wind are important in the origins of circulated and mixed water masses. These winds are both frequent and strong. They have, as a result, a great effect on the water environment of Lake Etang de Berre. In theory, the annual precipitation in this region is well over eight times the water mass of the lake. The water of the Durance River flows into Lake Etang de Berre through the EDF Canal, amounting to 90% of the precipitation. However, reduction of rainfall in dry seasons has a serious effect on the hydrological characteristics of the lake. The temperature in the winter is partially caused by the low temperature of fresh water, particularly that of the Durance River. The hydrological season of fresh and brackish water is about one month ahead of the hydrological season of sea water in its vicinity. The salinity of Lake Etang de Berre runs approximately 3$\textperthousand$, except at lower levels and near the entrance to the Caronte Canal. However, when the volume of the Durance River water is reduced in the summer and fall, the salinity rises to 15$\textperthousand$. In the lake, the ratio of fresh water to sea water is six to one (6:1). The large quantities of seston conveyed by rivers, particularly the Durance diversion, strongly reduce the transparency in the brackish waters. Although the amount of sunshine is also notable, transparency is slight because of the large amount of seston, carried chiefly by Tripton in the fresh water of the Durance River. Therefore, photosynthesis generally occurs only in the surface layer. The transparency progressively increases from freshwater to open seawater, as mineral particles sink to the bottom (about 1.7kg $m^{-2}a^{-1}$ on the average in brackish lakes). The concentration of dissolved oxygen and the rate of oxygen saturation in seawater (Carry-le-Rouet) ranged from 5.0 to 6.0 $m\ell$ㆍ.$1^{-1}$, and from 95 to 105%, respectively. The amount of dissolved oxygen in Etang de Berre oscillated between 2.9 and 268.3%. The monographs of phosphate, nitrate, nitrite and silicate were published as a part of a study on the ecology of phytoplankton in these environments. Horizontal and vertical distributions of these nutriments were studied in detail. The recent diversion of the Durance River into Lake Etang de Berre has effected a fundamental change in this formerly marine environment, which has had a great impact in its plankton populations. A total of 182 taxa were identified, including 111 Bacillariophyceae, 44 Chlorophyceae, and 15 Cyanophyceae. The most abundant species are small freshwater algae, mainly Chlorophyceae. The average density is about $10^{8}$ cells $1^{-1}$ in Lake Etang de Berre, and about double that amount in Lake Etang de Vaine. Differences in phytoplankton abundance and composition at the various stations or at various depths are slight. Cell biovolume V (equivalent to true biomass), plasma volume VP (‘useful’ biomass) and, simultaneously. the cell surface area S and S/V ratio through the measurement of cell dimensions were computed as the parameters of phytoplankton productivity and metabolism. Pigment concentrations are generally very high on account of phytoplankton blooms by Cyanophyceae, Chlorophyceae and Cryptophyceae. On the other hand, in freshwaters and marine waters, pigment concentrations are comparatively low and stable, showing slight annual variation. The variations of ATP concentration were closely related to those of chlorophyll a and phytoplankton blooms only in marine waters. The carbon uptake rates ranged between 38 and 1091 mg$Cm^{-2}d^{-1}$, with an average surface value of 256 mg; water-column carbon-uptake rates ranged between 240 and 2310 mg$Cm^{-2}d^{-1}$, with an average of 810, representing 290 mg$Cm^{-2}$, per year 45 000 tons per year of photosynthetized carbon for the whole lake. Gross photosynthetic production measured by the method of Ryther was studied over a 2-year period. The values obtained from marine water(Carry-le-Rouet) ranged from 23 to 2 337 mg$Cm^{-2}d^{-1}$, with a weighted average of 319, representing about 110 gCm$^{-2}$ per year. The values in brakish water (Etang de Berre) ranged from 14 to 1778 mg$Cm^{-2}d^{-1}$, with a weighted average of 682, representing 250 mg$Cm^{-2}$ per year and 38 400 tons per year of photosynthesized carbon for the whole lake.

Effect of the Feeding Belly Fat on Plasma Lipids Levels in Rats (삼겹살기름의 섭취가 흰쥐의 혈액지질 수준에 미치는 영향)

  • 박병성
    • Food Science of Animal Resources
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    • v.24 no.2
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    • pp.189-197
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    • 2004
  • This study investigated the effect of belly fat on the plasma lipid concentrations in rats. The results were obtained from the rats that had been fed the experimental purified diets containing 5% corn oil (C) as the control, 5% commercial lard (Tl), 5% belly fat (T2), 10% belly fat(T3), and those given diet(T4) by feeding either C or T3 alternately every 3 days for 30 days. The food intake and food efficiency were not show any significant difference among the treatments. The body weight gain tended to significantly increased when the feeding of added-belly fat in diets (p<0.05). The plasma triacylglycerides of T3 was higher than the other treatments, and significantly elevated as the number of feeding days of the diets with the belly fat passed when compared to diet C (p<0.05). The plasma total cholesterol of T3 showed the highest levels in the treatment groups, and was high in the order of T1, T2, T4, and there was a significant difference between the rats given the diet with belly fat and C (p<0.05). The plasma HDL-C of T2 and T3 was showed the lowest levels in the treatment groups. The plasma HDL-C of T1, T2, T3 and T4 groups were significantly decreased as the number of feeding days of the diets with the belly fat increased when compared to diet C (p<0.05). The plasma LDL-C and Al of T3 showed the highest levels in the treatment groups, and the levels were in order of T1, T2, T4. There was a significant difference between the groups of rats given the belly fat and C (p<0.05). The bleeding times significantly decreased as the number of feeding days of the belly fat diets increased, and T3 showed the lowest levels, there was a significant difference among the treatment groups (p<0.05). The whole blood clotting times of T3 showed the lowest values, and significantly decreased according to the number of days of the rats were fed the belly fat diet (p<0.05). These results showed that frequent consumption and high intake of pork belly can elevate the plasma triacylglyceride and cholesterol levels, and also accelerate red thrombus formation because belly fat contains high levels of saturated fatty acids and cholesterol.

Studies on the Embryo Transfer of In Vitro Matured/ In Vitro Fertilized Embryo in Hanwoo (한우 체외성숙.체외수정란의 수정란이식에 관한 연구)

  • 황환섭;장현용;김성곤;김종택;박춘근;정희태;김정익;양부근
    • Journal of Embryo Transfer
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    • v.19 no.1
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    • pp.1-10
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    • 2004
  • These studies were carried out to improve the reproductive efficiency through embryos transfer of Hanwoo IVM/IVF embryos. Following routine IVM/IVF procedure, oocytes and zygotes were cultured far 40 to 44 h in CRlaa medium with BSA. Then 2 to 8-cell embryos were removed the cumulus cell and were cultured in CRlaa medium containing 10% fatal bovine serum and 2.5 mM taurine in 5% $O_2$ and 5% $CO_2$ at 38.5$^{\circ}C$. The fresh embryos of the morulae and blastocysts cultured for 6 to 9 days in vitro or the frozen-thawed embryos were transferred into recipients. The pregnancy rates of the blastocyst produced for 6, 7, 8, and 9 days in vitro culture were 59.4, 68.2, 66.0 and 100%, respectively. In the developmental stage, pregnacy rates of early blastocysts (61.1%), blastocysts(64.7%) and expanded blastocysts(69.5%) were higher than that of morulae stage(20.0%). The pregnancy rates according to the corpus luteum grades of A, B and C in recipients were 73.6, 62.9 and 50.0%, respectively. Effects of donor-recipients synchrony of after day 2, 1 and 0, before day 1 and 2 on the pregnancy rates were 35.7, 65.5, 72.6, 67.9 and 60.0%, respectively. Pregnancy rates of the body condition score of recipients $\leq$2(71.3%) were higher than those of $\geq$3.0 score(40.0%). The pregnancy rates according to the parity of recipients when embryo was transferred to cow(70.6%) was higher than in heifer(59.1%). The pregnancy rates according to hormone treatment before embryo transfer were 69.9% in hCG + GnRH administration group and 63.0% in control group. Fresh and frozen-thawed embryos on the pregnancy rates were 70.6 and 36.4%, respectively. Pregnancy rates in single and AI+single was 90.0% and 64.8%. Pregnancy rates in twin induction was better than in single. These results indicate that pregnancy rates after transfer were affected on the embryo ages, donor-recipient synchrony, body condition score of recipients, corpus luteum status, parity and hormone treatment to recipients.

Hypoglycemic Effect of the Functional Food Manufactured by Fermented Soybean as Main Materials in Streptozotosin - Induced Diabetic Rats (Streptozotocin 유발 당뇨쥐에 있어서 발효콩을 주원료로 한 기능성 식품의 혈당강하 효과)

  • 최승필;최형택;이효진;문선영;김수현;이범구;이득식;함승시
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.7
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    • pp.1126-1132
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    • 2004
  • The present study was undertaken to evaluate the effect of functional food, which was processed with fermented soybean as main ingredient (FS), on the body weight, organ weight, plasma glucose, and plasma lipid in diabetic rats caused by streptozotocin (STZ). The body weight was decreased more slowly in the FS group than in the diabetic, and the food intake increased significantly in all diabetic groups. The food efficiency was very low in all diabetic groups, but increased significantly in the FS groups than diabetic control (p<0.05). In comparing the weight of organ, the weight of liver and kidney were increased in all diabetic groups than in the control, and decreased slightly in FS groups. The weight of heart and spleen were not different among all test groups. In the oral glucose tolerance test, the blood glucose in the diabetic group was the highest in 60 minutes. And the blood glucose in the FS group was the highest in 30 minutes, and decreased significantly after 120 minutes to the level of fasting glucose. The glucose in serum was decreased significantly in the FS groups fed the functional food for 4 weeks, compared to the diabetic control (p<0.05). Total cholesterol, triglyceride and atherogenic index (AI) in serum were significantly higher in diabetic control, compared to the normal (p<0.05), and decreased by 16.4%, 15.4% and 48.3%, respectively, in the FS fed 400 mg/kg of functional food. HDL-cholesterol was increased significantly in the FS-400, compared to the diabetic control. These results support that functional food using fermented soybean improve glucose and lipid metabolism in diabetic rats.

Studies on the Selective Separation and Preconcentration of Cr(VI) Ion by XAD-16-Chromotropic Acid Chelating Resin (XAD-16-Chromotropic Acid 킬레이트 수지에 의한 몇 가지 금속이온의 선택적 분리 및 농축에 관한 연구)

  • Lee, Won;Lee, Chang-Youl;Kim, Mi-Kyoung;Kim, In-Whan
    • Analytical Science and Technology
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    • v.17 no.3
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    • pp.199-210
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    • 2004
  • A new polystyrene-divinylbenzene chelating resin containing 4,5-dihydroxy-naphthalene-2,7-disulfonic acid (chromotropic acid : CTA) as functional group has been synthesized and characterized. The sorption and desorption properties of this chelating resin for Cr(III) ion and Cr(VI) ion including nine metal bloodstain. As a results, FOB test kit could be effectively applied to identification of human blood at chelating resin was stable in acidic and alkaline solution. The Cr(VI) ion is selectively separated from Cr (III) ion at pH 2 and the maximum sorption capacity of Cr(VI) ion is 1.2 mmol/g. In the presence of anions such as $F^-$, $SO{_4}^{2-}$, $CN^-$, $CH_3COO^-$, $NO{_3}^-$, the sorption of Cr(VI) ion was reduced but anions such as $PO{_4}^{3-}$ and $Cl^-$ revealed no interference effect. The elution order of metal ions obtained from breakthrough capacity and overall capacity at pH 2 was Cr(VI)>Sn(II)>Fe(III)>Cu(II)>Cd(II)${\simeq}Pb(II){\simeq}Cr(III){\simeq}Mn(II){\simeq}Ni(II){\simeq}Al(III)$. Desorption characteristics for Cr(VI) ion was investigated with desorption agents such as $HNO_3$, HCl, and $H_2SO_4$. It was found that the ion showed high desorption efficiency with 3 M HCl. As the result, the chelating resin, XAD-16-CTA was successfully applied to separation and preconcentration of Cr (VI) ion from several metal ions in metal finishing works.

Antimutagenic Effects of Korean Bamboo Trees and Inhibitory Effect of Hepatic Toxicity of Bamboo Extracts Coated Rice (한국산 대나무의 항돌연변이 효과 및 대나무 코팅쌀의 간 독성 억제효과)

  • Lee, Min-Ja;Kim, Eun-Young;Jeong, Keun-Ok;Park, Kun-Young;Moon, Gap-Soon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.8
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    • pp.1279-1285
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    • 2004
  • To evaluate the antimutagenic effect and hepato protective of bamboo trees and bamboo byproduct, hot-water extracts from four kinds of bamboo [wang-dae (Phyllostachys bambusoides S. et Z.), som-dae (Phyllostachys nigra var. henonis), maengjong-juk (Phyllostachys pubescens) and o-juk (Phyllostachys nigra Munro)] and maengjong-juk extract coated rice were evaluated for antimutagenicity by Ames test using Salmonella typhimurium TA100. Bamboo extracts showed strong antimutagenic activity in the Ames test which MNNG was used as mutagen in the absence and presence of S9 mix. Maengjong-juk extract coated rice diet suppressed the loss of body weight significantly. Food intake was increased in maengjong-juk extract coated rice supplemented group but showed no significant differences between control and maengjong-juk extract coated rice diet groups. Food efficiency of maengjong-juk extract coated rice supplemented group was significantly higher than that of the control group. Liver weight was significantly increased by maengjong-juk extract coated rice diet administration. Plasma GOT & GPT activities of rabbit were significantly suppressed in maengjong-juk extract coated rice supplemented group. These results suggest that bamboo trees extracts and maengjong-juk extract coated rice are bioavailable resource on treatment of cardiovascular disease, such as atherosclerosis and hypercholesterolemia.

Studies on Requirements of Optimum Dietary Essential Fatty Acids in Juvenile Eel, Anguilla japonica (치어기 뱀장어의 사료내 필수지방산 요구량에 관한 연구)

  • 배준영;한경민;박건준;배승철
    • Journal of Aquaculture
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    • v.17 no.4
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    • pp.275-281
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    • 2004
  • The present study was conducted to evaluate dietary requirements for essential fatty acids (EFAs) such as linoleic acid (LA, l8:2n-6), -lenolenic acid (LNA, 18:3n-3), or docosahexaenoic acid (DHA, 22:6n-3), eicosapentaenoic acid (EPA, 20:5n-3) and arachidonic acid (ARA, 20:4n-6) in juvenile eel Anguilla japonica cultured in a recirculating system for 16 weeks. The experimental diets contained 50% crude protein, 10% crude lipid and 3800 kcal/kg energy.Brown fish meal and blood meal were used as the main protein sources, while coconut oil, com oil and linseed oil were used as the lipid source to yield target fatty acids ratios. At the end of the trial, the effects of essential fatty acids supplementation on weight gain (WG), specific growth rate (SGR), feeding efficiency (FE), proximate composition andwhole body fatty acids contents were examined. WG, SGR, and FEof eels fed diet D2, D3, was significantly higher (P<0.05) than those of fish fed the other diets. Whole body HUFA concentration of eels fed D 1 was significantly lower (P<0.05) than those fed the other diets. HUFA/SFA (saturated fatty acids) ratio of whole body in eels fed diets D2, D3 and D6 were significantly higher than that of eels fed diet D1 (P<0.05).DHA/EPA ratio of whole body in eels fed diet D7was significantly higher than those fed the other diets; and eels fed diet D5 showed the lowest DHA/EPA ratio among all the dietary treatments (P<0.05).Based on the experimental results, we concluded that LNA (n-3) and LA (n-6) were necessary for optimum growth of juvenile eel, and the dietary requirement of LNA and LA were 0.35∼0.5% and 0.5∼0.65%, respectively.

Feasibility of Optoelectronic Neural Stimulation Shown in Sciatic Nerve of Rats (흰쥐의 좌골 신경 자극을 통한 광전 자극의 가능성에 대한 연구)

  • Kim Eui tae;Oh Seung jae;Baac Hyoung won;Kim Sung june
    • Journal of Biomedical Engineering Research
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    • v.25 no.6
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    • pp.611-615
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    • 2004
  • A neural prostheses can be designed to permit stimulation of specific sites in the nervous system to restore their functions, lost due to disease or trauma. This study focuses on the feasibility of optoelecronic stimulation into nervous system. Optoelectronic stimulation supplies, power and signal into the implanted optical detector inside the body by optics. It can be effective strategy especially on the retinal prosthesis, because it enables the non-invasive connection between the external source and internal detector through natural optical window 'eye'. Therefore, we designed an effective neural stimulating setup by optically based stimulation. Stimulating on the sciatic nerve of a rat with proper depth probe through optical stimulation needs higher ratio of current spreading through the neural surface, because of high impedance of neural interface. To increase the insertion current spreading into the neuron, we used a parallel low resistance compared to load resistance organic interface and calculated the optimized outer parallel resistance for maximum insertion current with the assumption of limited current by photodiode. Optimized outer parallel resistance was at a range of 500Ω-700Ω and a current was at a level between 580uA and 650uA. Stimulating current efficiency from initial photodiode induced current was between 47.5 and 59.7%. Various amplitude and frequency of the optical stimulation on the sciatic nerve showed the reliable visual tremble, and the action potential was also recorded near the stimulating area. These result demonstrate that optoelectronic stimulation with no bias can be applied to the retinal prosthesis and other neuroprosthetic area.