• Title/Summary/Keyword: V2C

Search Result 9,802, Processing Time 0.043 seconds

Performance of Nano Ceramic Filter for the Removal of Ultra Fine Particles (초미세입자 제거를 위한 나노세라믹 필터의 성능 평가)

  • Kim, Jong-Won;Ahn, Young-Chull;Yi, Byeong-Kwon;Jeong, Hyeon-Jae
    • Proceedings of the SAREK Conference
    • /
    • 2009.06a
    • /
    • pp.751-756
    • /
    • 2009
  • In the perspective of saving energy in buildings, the high performance of insulation and air tightness for improving the heating and the cooling efficiency, has brought economically positive effects. However, these building energy saving technologies cause the lack of ventilation, which is the direct cause of increasing the indoor contaminants, and is also very harmful to the residents, because they spend over 90% of their time indoors. Therefore, the ventilation is important to keep the indoor environment clean and it can also save the energy consumption. In this study, a HEPA type nano ceramic filter is designed as a passive ventilation system to collect airborne particles and to supply fresh outdoor air. The double layer filter, which has $30{\mu}m$ in diameter at the conditions of 10wt% of concentration and 3kV/cm of the electric intensity, is produced by electrospinning. The filtration coating technology is confirmed in the solution with $SiO_2$ nano particles using polymer nano fibers. Also double layer filters are coated with $SiO_2$ nano particles and finally the porous construction materials are made by sintering in the electric furnace at $200{\sim}1400^{\circ}C$. The efficiency is measured 96.67% at the particle size of $0.31{\mu}m$, which is slightly lower than HEPA filter. However the efficiency is turned out to be sufficient.

  • PDF

Mathematical Model for the Removal of SO2 by the γ-Alumina Impregnated with CuO (γ-Alumina에 담지된 산화구리에 의한 SO2의 제거에 관한 수치모사)

  • Jeon, Bup Ju;Hong, In Kwon;Park, Kyung Ai;Jung, Il Hyun
    • Applied Chemistry for Engineering
    • /
    • v.5 no.3
    • /
    • pp.385-394
    • /
    • 1994
  • Numerical solutions were obtained to the model equations for various of the parameters characterizing the pore structure, effective internal diffusion, and the chemical reaction constant. The conversion was decreased with the cause of pore closure at the surface of reacting particles, reduction of porosity, surface area of reaction and effective diffusion coefficient in the solid with the progress of reaction. Total conversion was strongly dependent on the local conversion at surface. According to the decreasing of impregnated concentration of the copper oxide and the increase of the flue gases concentration, total conversion was increased. The conversion was affected by gas flow rate and pore size distribution in the reacting solid.

  • PDF

Microstructural Observations on Quaternary ZnMgSSe/GaAs Epilayer Grown by MBE (MBE로 성장시킨 4원계 ZnMgSSe/GaAs 에피층의 미세구조 관찰)

  • Lee, Hwack-Joo;Ryu, Hyun;Park, Hae-Sung;Kim, Tae-Il
    • Applied Microscopy
    • /
    • v.25 no.3
    • /
    • pp.82-89
    • /
    • 1995
  • High resolution transmission electron microscopic observations on quaternary $Zn_{1-x}Mg_{x}S_y$ $S_{1-y}$(x=0.13, y=0.16) on (001) GaAs substrate grown up to $1.2{\mu}m$ with 20nm ZnSe buffer layer at $300^{\circ}C$ by RIBER MBE system which has a single growth chamber were investigated by HRTEM working at 300kV with point resolution of 0.18nm. The ZnSe buffer layer maintains the coherency with the GaAs substrate. The stacking faults had begun at ZnSe buffer/$Zn_{1-x}Mg_{x}S_{y}S_{1-y}$ interface, whose length and spacing became larger than 60nm and wider than 40nm, respectively. The inverse triangular stacking fault was bounded by stacking faults which were formed on {111} planes with different variants. There exists rare stacking faults inside the triangular defect. The epilayer surrounded by the straight stacking faults, which had formed in the same direction, became the columnar structure.

  • PDF

Microstructure Characterization of Ternary ZnSSe/GaAs Epilayer Grown by MBE (MBE로 성장시킨 3원계 ZnSSe/GaAs 에피층의 미세구조 특성)

  • Lee, Hwack-Joo;Ryu, Hyun;Park, Hae-Sung;Kim, Tae-Il
    • Applied Microscopy
    • /
    • v.25 no.3
    • /
    • pp.75-81
    • /
    • 1995
  • The microstructural characterization of ternary $ZnS_{x}Se_{1-x}$(x=0.085) on GaAs(001) substrate grown up to $2{\mu}m\;at\;300^{\circ}C$ by molecular beam epitaxy(MBE) which has a single growth chamber was investigated by high resolution transmission electron microscope (HRTEM) working at 300 kV with point resolution of 0.18nm. The interface in the ZnSSe/GaAs specimen maintains a pseudomorphism with the substrate, but the epilayer has high density of stacking faults and moire fringes. The pits which had formed along <111> direction were found at the interface of ZnSSe/GaAs. The pits were responsible for producing defects in both epilayer and substrate. The wavy interface which has the difference of 15nm in height was found to maintain the pseudomorphism with the substrate and no stacking faults were found around the interface. However there exists faint and fine moire fringes in the epilayer near interface.

  • PDF

A Study on the Quality Control of the Radioimmunoassay Serum $T_3$(triiodothyronine) (혈청(血淸)$T_3$의 방사면역측정시(放射免疫測定時) 정도관리(精度管理)에 관(關)한 검토(檢討))

  • Kyong, Kwang-Hyon;Choi, Young-Sook
    • Journal of radiological science and technology
    • /
    • v.5 no.1
    • /
    • pp.55-62
    • /
    • 1982
  • Measurement of triiodothyronine($T_3$) concentration is useful for the diagnosic and treatment of thyroid gland diseases. Fundermental studies of measurement of $T_3$ concentration by radioimmunoassay were performed and values determined by commercially available kit, Coat-A-Count, Diagnostic Products Corporation. The optimal utilization of the radioimmunoassay in measuring $T_3$ concentrations is dependant not only on high quality performance of the assay, but also on their appropriate application to the clinical situation. These are several aspects that must be considered in every individual case. These include factors such as accurate pippeting in reagent preparation in the assay and through decanting to remove all visible moisture after incubation steps and so forth. In attempt to assess quality control of the radioimmunoassay of serum $T_3$, serum pools with high, medium, low $T_3$ concentrations were assayed for each of 5 samples. The results obtained with this study were as follow: 1. The coefficient of variation(C. V.) for the standard curve ranged between $0.2{\sim}3.5%$. 2. It was necessary that both incubation time and temperature should correctly be maintained all the in the assay performance. 3. The precison with the $T_3$ RIA procedure was good. 4. The measured values of serially diluted serum $T_3$ concentration with Ong/dl standard solution was proportional to the predicted values. However dilution curve of distilled water was not strait. 5. Calculated $T_3$ values of patient serum in normal group was $107.8{\pm}25.90ng/dl$ in male patient and $127.29{\pm}24.08ng/dl$ in female patient.

  • PDF

Effect of Coating Method on the Survival Rate of L. plantarum for Chicken Feed

  • Lee, Sang-Yoon;Jo, Yeon-Ji;Choi, Mi-Jung;Lee, Boo-Yong;Han, Jong-Kwon;Lim, Jae Kag;Oh, Jae-Wook
    • Food Science of Animal Resources
    • /
    • v.34 no.2
    • /
    • pp.230-237
    • /
    • 2014
  • This study was designed to find the most suitable method and wall material for microencapsulation of the Lactobacillus plantarum to maintain cell viability in different environmental conditions. To improve the stability of L. plantarum, we developed an encapsulation system of L. plantarum, using water-in-oil emulsion system. For the encapsulation of L. plantarum, corn starch and glyceryl monostearate were selected to form gel beads. Then 10% (w/v) of starch was gelatinized by autoclaving to transit gel state, and cooled down at $60^{\circ}C$ and mixed with L. plantarum to encapsulate it. The encapsulated L. plantarum was tested for the tolerance of acidic conditions at different temperatures to investigate the encapsulation ability. The study indicated that the survival rate of the microencapsulated cells in starch matrix was significantly higher than that of free cells in low pH conditions with relatively higher temperature. The results showed that corn starch as a wall material and glycerol monostearate as a gelling agent in encapsulation could play a role in the viability of lactic acid bacteria in extreme conditions. Using the current study, it would be possible to formulate a new water-in-oil system as applied in the protection of L. plantarum from the gastric conditions for the encapsulation system used in chicken feed industry.

Single-Electron Logic Cells and SET/FET Hybrid Integrated Circuits

  • Kim, S.J.;Lee, C.K.;Lee, J.U.;Choi, S.J.;Hwang, J.H.;Lee, S.E.;Choi, J.B.;Park, K.S.;Lee, W.H.;Paik, I.B.;Kang, J.S.
    • JSTS:Journal of Semiconductor Technology and Science
    • /
    • v.6 no.1
    • /
    • pp.52-58
    • /
    • 2006
  • Single-electron transistor (SET)-based logic cells and SET/FET hybrid integrated circuits have been fabricated on SOI chips. The input-output voltage transfer characteristic of the SET-based complementary logic cell shows an inverting behavior where the output voltage gain is estimated to be about 1.2 at 4.2K. The SET/FET output driver, consisting of one SET and three FETs, yields a high voltage gain of 13 and power amplification with a wide-range output window for driving next circuit. Finally, the SET/FET literal gate for a multi-valued logic cell, comprising of an SET, an FET and a constant-current load, displays a periodic voltage output of high/low level multiple switching with a swing as high as 200mV. The multiple switching functionality of all the fabricated logic circuits could be enhanced by utilizing a side gate incorporated to each SET component to enable the phase control of Coulomb oscillations, which is one of the unique characteristics of the SET-based logic circuits.

MC3T3-E1 osteoblast adhesion to laser induced hydroxyapatite coating on Ti alloy

  • Huang, Lu;Goddard, Samuel C.;Soundarapandian, Santhanakrishnan;Cao, Yu;Dahotre, Narendra B.;He, Wei
    • Biomaterials and Biomechanics in Bioengineering
    • /
    • v.1 no.2
    • /
    • pp.81-93
    • /
    • 2014
  • An in vitro cell study evaluating cell adhesion to hydroxyapatite (HA) coated prosthetic Ti-6Al-4V alloy via laser treatment is presented in comparison with uncoated alloy. Based on our previous in vitro biocompatibility study, which demonstrated higher cell attachment and proliferation with MC3T3-E1 preosteoblast cells, the present investigation aims to reveal the effect of laser coating Ti alloy with HA on the adhesion strength of bone-forming cells against centrifugal forces. Remaining cells on different substrates after centrifugation were visualized using fluorescent staining. Semi-quantifications on the numbers of cells were conducted based on fluorescent images, which demonstrated higher numbers of cells retained on HA laser treated substrates post centrifugation. The results indicate potential increase in the normalized maximum force required to displace cells from HA coated surfaces versus uncoated control surface. The possible mechanisms that govern the enhancing effect were discussed, including surface roughness, chemistry, wettability, and protein adsorption. The improvement in cell adhesion through laser treatment with a biomimetic coating could be useful in reducing tissue damage at the prosthetic to bone junction and minimizing the loosening of prosthetics over time.

The Effects of Purified Artemia Extract Proteins on Proliferation, Differentiation and Apoptosis of Human Leukemic HL-60 Cells

  • Deezagi, Abdolkhaleg;Chashnidel, Azadeh;Hagh, Neda Vaseli;Shahraki, Mahvash Khodabandeh
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.17 no.12
    • /
    • pp.5139-5145
    • /
    • 2016
  • There has been an increment in the number of studies focused on marine bioactive materials. Many peptides and other biomaterials with anticancer potential have been extracted from various marine animals. Artemia extracts have found uses in sun-light protection cosmetics and anti-aging products. However, contents of biochemical compounds in Artemia spp. and molecular mechanisms of have not been clearly studied in leukemic cells in vitro. In this work, we isolated and purified proteins of Artemia Urmiana. Six clear fractions (A-F) observed on DEAE-cellulose chromatography were assayed for effects on cell growth, differentiation and apoptosis using the human leukemic HL-60 cell line. Cell proliferation analysis by MTT and BrdU assays indicated that did not affect cells, growth. Cells treated with crude extract and fractions A, B and C, but not E and F (up to $100{\mu}g/mL$), exhibited increase of cell growth in a dose dependent manner. Stimulatory effects of fraction D were observed at concentrations of $10{\mu}g/mL$ and above. In nitro blue tetrazolium (NBT) reduction assays, treatment with $100{\mu}g/mL$ of fraction E or F for 96 hr increased the fraction of differentiated cells up to $14.8{\pm}3.56%$ and $16.5{\pm}2.08%$ respectively. Combination of those fractions with retinoic acid had significant synergistic effects on the differentiation of cells ($56.8{\pm}3.7%$ and $67.4{\pm}4.2%$, $p{\leq}0.01$). Annexin-V FITC staining for apoptosis and flow cytometric assays indicated induction of apoptosis by fractions E and F up to 23.8 and 31.8% of cells.

Potent Anticancer Effects of Lentivirus Encoding a Drosophila Melanogaster Deoxyribonucleoside Kinase Mutant Combined with Brivudine

  • Zhang, Nian-Qu;Zhao, Lei;Ma, Shuai;Gu, Ming;Zheng, Xin-Yu
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.13 no.5
    • /
    • pp.2121-2127
    • /
    • 2012
  • Objective: Deoxyribonucleoside kinase of Drosophila melanogaster (Dm-dNK) mutants have been reported to exert suicide gene effects in combined gene/chemotherapy of cancer. Here, we aimed to further evaluate the capacity of the mutanted enzyme and its potential for inhibiting cancer cell growth. Methods: We altered the sequence of the last 10 amino acids of Dm-dNK to perform site-directed mutagenesis and constructed active site mutanted Dm-dNK (Dm-dNKmut), RT-PCR and western bloting studies were used to reveal the expression of lentivirus mediated Dm-dNKmut in a breast cancer cell line (Bcap37), a gastric cancer cell line (SGC7901) and a colorectal cancer cell line (CCL187). [3H]-labeled substrates were used for enzyme activity assays, cell cytotoxicity was assessed by MTT assays, cell proliferation using a hemocytometer and apoptosis induction by thenannexin-V-FITC labeled FACS method. In vivo, an animal study was set out in which BALB/C nude mice bearing tumors were treated with lentivirus mediated expression of Dm-dNKmut with the pyrimidine nucleoside analog brivudine (BVDU, (E)-5-(2-bromovinyl)-(2-deoxyuridine). Results: The Dm-dNKmut could be stably expressed in the cancer cell lines and retained its enzymatic activity. Moreover, the cells expressing Dm-dNKmut exhibited increased sensitivity in combination with BVDU, with induction of apoptosis in vitro and in vivo. Conclusion: These findings underlined the importance of BVDU phosphorylated by Dm-dNKmut in transduced cancer cells and the potential role of Dm-dNKmut as a suicide gene, thus providing the basis for future intensive research for cancer therapy.