• Title/Summary/Keyword: selective addition

Search Result 818, Processing Time 0.031 seconds

Development of Passive Solar Water Heater 1. Selective absorbers (자연형 온수 급탕시스템 개발)

  • Lee, K.D.;Auh, P.C.M.;You, C.K.
    • Solar Energy
    • /
    • v.4 no.2
    • /
    • pp.29-36
    • /
    • 1984
  • This paper reviews the current status of R&D work on selective absorber materials. For the efficient utilization of solar energy, various types of selective absorber materials are being used for solar hot water heaters. Many selective absorbers which have been proposed and designed up to data are classified according to the absorption mechanisms. Temperature-time cycle method is often recommended for the measurement of solar absorptance. In addition, conversion efficiency of the solar collector with selective surface is compared with one with black paint surface.

  • PDF

Design analysis of high efficiency crystalline silicon solar cell using the selective emitter (선택적 에미터를 적용한 고효율 결정질 실리콘 태양전지 구조 설계)

  • Lim, Jong-Keun;Lee, Won-Jae;Moon, In-Sik;Oh, Hoon;Cho, Eun-Chel
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2009.11a
    • /
    • pp.355-358
    • /
    • 2009
  • This paper presents the technology of selective emitter for high efficiency crystalline silicon solar cell. The effect of selective emitter is analyzed by using the simulation program for solar cell, PC1D. The selective emitter shows better spectral response in short wavelength regions compared to homogeneous emitter. Therefore, the efficiency of solar cell with selective emitter can be improved by changing the sheet resistance from 60 $\Omega/\square$ to 120 $\Omega/\square$. In addition, the power loss of solar cell can be minimized by optimizing width and gap of the finger electrodes on the selective emitter.

  • PDF

Application of Ion-Selective Electrodes to Measure Ionic Concentrations of Macronutrients in Hydroponics (수경재배 시 다량 이온 농도 측정을 위한 이온 선택성 전극의 응용)

  • Kim, Min-Su;Park, Tu-San;Cho, Seong-In
    • Journal of Biosystems Engineering
    • /
    • v.32 no.1 s.120
    • /
    • pp.37-43
    • /
    • 2007
  • This study was carried out to investigate the applicability of PVC membrane-based ion-selective electrodes for macronutrients (K, Ca, and N) by measuring of potassium, calcium, nitrate ions in hydroponic nutrient solution. The capabilities of two ion-selective membranes with varying chemical compositions for each ion were evaluated in terms of sensitivity, selectivity, and lifetime to choose sensing elements suitable for measuring typical ranges of nutrient concentrations in hydroponic solutions. The selected calcium and nitrate ion-selective membranes showed effectively sensitive responses to calcium and nitrate ions with lifetimes of 25 and 15 days, respectively. The addition of a cation additive to the potassium membrane cocktail allowed its sensitivity to be increased whereas its lifetime was reduced from 30 days to 10 days.

Cr-Co removable partial denture treatment fabricated by selective laser melting: a case report (Selective Laser Melting을 이용한 코발트-크롬 가철성 국소의치의 수복 증례)

  • Yim, Ji-Hun;Shin, Soo-Yeon
    • Journal of Dental Rehabilitation and Applied Science
    • /
    • v.37 no.1
    • /
    • pp.39-47
    • /
    • 2021
  • Compared to conventional method, if metal framework of removable partial denture is fabricated by selective laser melting, various laboratory works are omitted, saving time and simplifying the process. In addition, metal framework with homogeneous density can be obtained, expecting excellent mechanical properties, especially resistance to fatigue fracture. In these cases, impression were taken using conventional methods in partial edentulous patients, master casts were fabricated and scanned to obtain digital data. After designing the metal frameworks on the scanned data, removable partial dentures were fabricated using selective laser melting methods. Through these procedure, satisfactory outcomes were achieved both in functional and esthetic aspects.

Selective tyrosine conjugation with a newly synthesized PCB -TE2A-luminol bifunctional chelator

  • Subramani Rajkumar;Hyun Park;Abhinav Bhise;Seong Hwan Cho;Jung Young Kim;Kyo Chul Lee;Jeongsoo Yoo
    • Journal of Radiopharmaceuticals and Molecular Probes
    • /
    • v.7 no.2
    • /
    • pp.85-91
    • /
    • 2021
  • Selective amino acid conjugation of bulky antibodies is a valuable asset for real-time diagnosis and therapy. However, selective conjugation incorporating a chelate-bearing radioactive atom into an antibody without affecting its immunoreactivity is a challenging task. A bifunctional chelator (BFC), a selective amino acid-targeting probe, and a linker have been developed to overcome this problem. Here, we report the synthesis of a novel propylene cross-bridged chelator (PCB)-1,8-N,N'-bis-(carboxymethyl)-1,4,8,11-tetraazacyclotetradecane (TE2A)-luminol BFC via a click reaction and radiolabel it with a 64Cu ion for tyrosine-selective conjugation of trastuzumab. In the initial optimization study, we tried different oxidative addition conditions such as electro-oxidation, hemin, horseradish peroxidase, iodogen tube, chloramine-T, and iodo beads. In this study, up to 82% of 64Cu-PCB-TE2A-luminol was conjugated with the antibody in an iodo bead-catalyzed oxidative addition reaction with an isolated yield of 24.4%.

Selective Cytotoxic Effects of Doenjang (Korean Soybean Paste) Fermented with Bacillus Strains on Human Liver Cell Lines

  • Choi, Myeong-Rak;Lim, Hyun-Soo;Chung, Yoon-Ju;Yoo, Eun-Jeong;Kim, Jong-Kyu
    • Journal of Microbiology and Biotechnology
    • /
    • v.9 no.4
    • /
    • pp.504-508
    • /
    • 1999
  • This report compares the selective cytotoxic effects of Doenjang fermented by various Bacillus strains (Bacillus sp. SS9, SSA3, and PM3) on human liver cell lines with that of conventional Doenjang (DTY, DTG, and DTK) and commercial Doenjang (DCM, DCD, and DCS). To investigate selective cytotoxic effects of Doenjang extracts, the cell density of HepG2 (Hepatocellular carcinoma) and CCL-13 (cells derived from human normal liver) was estimated after addition of the extracts by using a viable cell counting method. The maximum selectivity ratio ($IC_{50}$value against CCL-13/$IC_{50}$ value aganist HepG2) was observed by PM3 (extracts of Doenjang fermented with Bacillus sp. PM3). As for morphological changes shown by the addition of PM3 into HepG2 and CCL-13 cultures, HepG2 was significantly disrupted, however, CCL-13 was not affected. Also, the growth rate of HepG2 was decreased significantly by the addition of PM3. Consequently, PM3 showed a more detrimental effect on HepG2 than that on CCL-13.

  • PDF

THE STUDY ON STABLE EMULSION SYSTEM AND SELECTIVE ADDITION OF ACTIVE INGREDIENT IN W/O/W ONE STEP MULTIPLE EMULSION

  • Kim, Se-gie;Park, Hee-nam;Kim, Tae-kyoo
    • Journal of the Society of Cosmetic Scientists of Korea
    • /
    • v.24 no.3
    • /
    • pp.96-104
    • /
    • 1998
  • It was possible to produce W/O/W one step multiple emulsion on the system which satisfied following conditions. 1. 1-5% of hydrophilic liquid surfactant over HLB20 and lipophilic liquid surfactant which has HLB 3∼5 2. Non wax copolymers as oil thickener 3. More than 0.5% of carbomer as aqueous thickener 4. The manufacturing process which neutralize the dispersed carbomer (2.0% in water), after emulsifying. For the selective addition into inner and outer aqueous phase, we melted the glucose in water before emulsifying. Using an Anthrone analysis method, we analyzed the encapsulation yield of glucose in inner water phase. It was possible to raise the water encapsulation yield of the multiple emulsion through the following conditions. 1. Using of anionic hydrophilic surfactant(HLB 40) and lipophilic surfactant (HLB 3∼5) 2. Controlling the ratio of hydrophilic surfactant and lipophilic surfactant 3. Strengthening interface with increase of non wax oil thickener. When the separated adding process of glucose was adopted, approximately 85% of glucose was added selectively within inner aqueous phase.

  • PDF

Low-Temperature Selective Epitaxial Growth of SiGe using a Cyclic Process of Deposition-and-Etching (증착과 식각의 연속 공정을 이용한 저온 선택적 실리콘-게르마늄 에피 성장)

  • 김상훈;이승윤;박찬우;심규환;강진영
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.16 no.8
    • /
    • pp.657-662
    • /
    • 2003
  • This paper presents a new fabrication method of selective SiGe epitaxial growth at 650 $^{\circ}C$ on (100) silicon wafer with oxide patterns by reduced pressure chemical vapor deposition. The new method is characterized by a cyclic process, which is composed of two parts: initially, selective SiGe epitaxy layer is grown on exposed bare silicon during a short incubation time by SiH$_4$/GeH$_4$/HCl/H$_2$system and followed etching step is achieved to remove the SiGe nuclei on oxide by HCl/H$_2$system without source gas flow. As a result, we noted that the addition of HCl serves not only to reduce the growth rate on bare Si, but also to suppress the nucleation on SiO$_2$. In addition, we confirmed that the incubation period is regenerated after etching step, so it is possible to grow thick SiGe epitaxial layer sustaining the selectivity. The effect of the addition of HCl and dopants incorporation was investigated.

Property Analysis of Solar Selective Coatings (태양 선택흡수막의 특성 분석)

  • Lee, Kil-Dong
    • Journal of the Korean Solar Energy Society
    • /
    • v.33 no.4
    • /
    • pp.31-38
    • /
    • 2013
  • The chemical composition of the black Cr solar selective coatings electrodeposited were investigated for property analysis by using a XPS(X-ray photoelectron spectroscopy) before and after annealing in air at $300^{\circ}C{\sim}500^{\circ}C$ for 120 hours. Black Cr selective coating exposed by solar radiation for 5 months was compared with annealed sample. In addition, The Cu solar selective coatings were prepared by thermal oxidation method for low temperature application. The samples obtained were characterized by using the optical reflectance measurements by using a spectrometer. Optical properties of oxidized Cu solar coatings were solar absorptance $({\alpha}){\simeq}0.62$ and thermal emittance $({\epsilon}){\simeq}0.41(100^{\circ}C)$. In the as-prepared Cr black selective coating, the surface of the coating was found to have Cr hydroxide and Cr. The Cr hydroxide of the major component was converted to $Cr_2O_3$ or $CrO_3$ form after annealing at $500^{\circ}C$ with the desorption of water molecules. The black Cr selective coating was degraded significantly at temperature of $500^{\circ}C$. The main optical degradation modes of this coating were diffusion of Cu substrate materials.

Stydies on the Selective Screening Method of Bifidobacteria Used in Yoghurt (호상 요구르트 제품에 이용되는 Bifidobacteria 의 선택적 검출 방법)

  • 박희경;허태련
    • Microbiology and Biotechnology Letters
    • /
    • v.23 no.2
    • /
    • pp.214-219
    • /
    • 1995
  • In fermentation of dairy products, bifidobacteria is used in conjunction with other lactic acid bacteria, such as L. acidophilus, L. bulgaricus and S. thermophilus, rendering the enumeration of bifidobacteria difficult. In order to develop optimum conditions for selective enumeration of bifidobacteria, we examined MIC of several antibiotics against various bifidobacteria and other lactic acid bacteria. The growth of L. acidophilus, L. bulgaricus and S. thermophilus were inhibited by lithium chloride at the concentration of less than 4 mg/ml, whereas growth inhibition of bifidobacteria occurred at concentrations over 6-10 mg/ml. Tetracycline and chloramphenicol were also found to selectively inhibit growth of other lactic acid bacteria at the concentration of 1-3 $\mu$g/ml. Addition of 6 mg/ml lithium chloride, 1 $\mu$g/ml, tetracycline or 3 $\mu$g/ml chloramphenicol to medium was found to be optimal for selective enumeration of bifidobacteria. By using these three inhibitory chemicals in the TPY medium, higher number of bifidobacteria were selectively isolated than with NPNL agar and LP agar.

  • PDF