• Title/Summary/Keyword: Molecular Flow

Search Result 890, Processing Time 0.024 seconds

A study on the characteristics of electron beam resist with addition of organometallic monomer (유기금속의 첨가에 따른 전자빔 레지스트 특성조사)

  • 박종관;이덕출;우호환;이종태;김보열
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 1994.11a
    • /
    • pp.152-155
    • /
    • 1994
  • The purpose of this paper is to develope an electron beam resist by the plasma polymerization. Plasma co-polymerized resist was prepared using an interelectrode gas-flow-type reactor. And then delineated pattern in the resist was developed with gas flow type reactor using Ar and O$_2$ gas as etching gas. We study about the effects of discharge power and mixing rate of the copolymerized thin film. The characteristics of molecular structure of thin film was investigated by FT-lR, DSC and GPC, and then was discussed in relation to its quality as a resist.

Experimental Study for the Identification of the Nascent Product of OH Heterogeneous Reaction with NaCl using Chemical Ionization Mass Spectrometry

  • Park, Jong-Ho;Ivanov, Andrey V.;Molina, Mario J.
    • Mass Spectrometry Letters
    • /
    • v.3 no.4
    • /
    • pp.108-111
    • /
    • 2012
  • An experimental study on the nascent product of the OH heterogeneous reaction with NaCl was performed under dry and wet conditions using a bead-filled flow tube system coupled to a high-pressure chemical ionization mass spectrometer. The ozone concentration in the flow tube for the atomic hydrogen removal was varied in order to control the conversion reaction of molecular chlorine into HCl for the identification of the nascent product. The mass spectrometric observation was that the $O_3$ introduction reduced the concentration HCl, while it increased the concentration of $Cl_2$ and ClO. Based on the experimental results, we suggest that the nascent product of the titled reaction is gaseous $Cl_2$, which is followed by fast conversion into HCl in presence of H. No significant difference in the concentration profile between under dry and wet (RH = 2%) conditions was observed.

Prediction of the Turbulent Mixing in Bare Rod Bundles

  • Kim, Sin;Chung, Bum-Jin
    • Nuclear Engineering and Technology
    • /
    • v.31 no.1
    • /
    • pp.104-115
    • /
    • 1999
  • The turbulent mixing rate is a very important variable in the thermal-hydraulic design of nuclear reactors. In this study, the turbulent mixing rate the fluid flows through rod bundles is estimated with the scale analysis on the flow pulsation phenomenon. Based upon the assumption that the turbulent mixing is composed of molecular motion, isotropic turbulent motion (turbulent motion without the flow pulsation), and How pulsation, the scale relation for the mixing is derived as a function of P/D, Re, and Pr. The derived scale relation is compared with published experimental results and shows good agreements. Since the scale relation is applicable to various Prandtl number fluid flows, it is expected to be useful for the thermal-hydraulic analysis of liquid metal coolant reactors as well as of moderate Prandtl number coolant reactors.

  • PDF

IMPLEMENTATION OF VELOCITY SLIP MODELS IN A FINITE ELEMENT NUMERICAL CODE FOR MICROSCALE FLUID SIMULATIONS (속도 슬립모델 적용을 통한 마이크로 유체 시뮬레이션용 FEM 수치 코드 개발)

  • Hoang, A.D.;Myong, R.S.
    • Journal of computational fluids engineering
    • /
    • v.14 no.2
    • /
    • pp.46-51
    • /
    • 2009
  • The slip effect from the molecular interaction between fluid particles and solid surface atoms plays a key role in microscale fluid transport and heat transfer since the relative importance of surface forces increases as the size of the system decreases to the microscale. There exist two models to describe the slip effect: the Maxwell slip model in which the slip correction is made on the basis of the degree of shear stress near the wall surface and the Langmuir slip model based on a theory of adsorption of gases on solids. In this study, as the first step towards developing a general purpose numerical code of the compressible Navier-Stokes equations for computational simulations of microscale fluid flow and heat transfer, two slip models are implemented into a finite element numerical code of a simplified equation. In addition, a pressure-driven gas flow in a microchannel is investigated by the numerical code in order to validate numerical results.

Estimation of nuclear DNA content of various bamboo and rattan species

  • Kumar, Prakash P.;Turner, Ian M.;Rao, A. Nagaraja;Arumuganathan, K.
    • Plant Biotechnology Reports
    • /
    • v.5 no.4
    • /
    • pp.317-322
    • /
    • 2011
  • We determined the nuclear DNA content (genome size) of over 35 accessions each of bamboo and rattan species from Southeast Asia. The 2C DNA per nucleus was quantified by flow cytometry. The fluorescence of nuclei isolated from the leaves and stained with propidium iodide was measured. The genome size of the bamboo species examined was between 2.5 and 5.9 pg DNA per 2C nucleus. The genome size of the rattan species examined ranged from 1.8 to 10.5 pg DNA per 2C nucleus. This information will be useful for scientists working in diverse areas of plant biology such as biotechnology, biodiversity, genome analysis, plant breeding, physiology and molecular biology. Such data may be utilized to attempt to correlate the genome size with the ploidy status of bamboo species in cases where ploidy status has been reported.

Multiplexed single-molecule flow-stretching bead assay for DNA enzymology

  • Lee, Ryanggeun;Yang, Keunsang;Lee, Jong-Bong
    • BMB Reports
    • /
    • v.52 no.10
    • /
    • pp.589-594
    • /
    • 2019
  • Single-molecule techniques have been used successfully to visualize real-time enzymatic activities, revealing transient complex properties and heterogeneity of various biological events. Especially, conventional force spectroscopy including optical tweezers and magnetic tweezers has been widely used to monitor change in DNA length by enzymes with high spatiotemporal resolutions of ~nanometers and ~milliseconds. However, DNA metabolism results from coordination of a number of components during the processes, requiring efficient monitoring of a complex of proteins catalyzing DNA substrates. In this min-review, we will introduce a simple and multiplexed single-molecule assay to detect DNA substrates catalyzed by enzymes with high-throughput data collection. We conclude with a perspective of possible directions that enhance capability of the assay to reveal complex biological events with higher resolution.

Post-cancer Treatment with Condurango 30C Shows Amelioration of Benzo[a]pyrene-induced Lung Cancer in Rats Through the Molecular Pathway of Caspase-3-mediated Apoptosis Induction -Anti-lung cancer potential of Condurango 30C in rats-

  • Sikdar, Sourav;Mukherjee, Avinaba;Bishayee, Kausik;Paul, Avijit;Saha, Santu Kumar;Ghosh, Samrat;Khuda-Bukhsh, Anisur Rahman
    • Journal of Pharmacopuncture
    • /
    • v.16 no.3
    • /
    • pp.11-22
    • /
    • 2013
  • Objectives: The present investigation aimed at examining if post-cancer treatment with a potentized homeopathic drug, Condurango 30C, which is generally used to treat oesophageal cancer, could also show an ameliorating effect through apoptosis induction on lung cancer induced by benzo[a]pyrene (BaP) in white rats (Rattus norvegicus). Methods: Lung cancer was induced after four months by chronic feeding of BaP to rats through gavage at a dose of 50 mg/kg body weight for one month. After four months, the lung-cancer-bearing rats were treated with Condurango 30C for the next one ($5^{th}$), two ($5^{th}-6^{th}$) and three ($5^{th}-7^{th}$) months, respectively, and were sacrificed at the corresponding time-points. The ameliorating effect, if any, after Condurango 30C treatment for the various periods was evaluated by using protocols such as histology, scanning electron microscopy (SEM), annexinV-FITC/PI assay, flow cytometry of the apoptosis marker, DNA fragmentation, reverse transcriptase-polymerase chain reaction (RT-PCR), immunohistochemistry, and western blot analyses of lung tissue samples. Results: Striking recovery of lung tissue to a near normal status was noticed after post-cancerous drug treatment, as evidenced by SEM and histology, especially after one and two months of drug treatment. Data from the annexinV-FITC/PI and DNA fragmentation assays revealed that Condurango 30C could induce apoptosis in cancer cells after post-cancer treatment. A critical analysis of signalling cascade, evidenced through a RT-PCR study, demonstrated up-regulation and down-regulation of different pro- and anti-apoptotic genes, respectively, related to a caspase-3-mediated apoptotic pathway, which was especially discernible after one-month and two-month drug treatments. Correspondingly, Western blot and immunohistochemistry studies confirmed the ameliorative potential of Condurango 30C by its ability to down-regulate the elevated epidermal growth factor receptor (EGFR) expression, a hallmark of lung cancer. Conclusion: The overall result validated a positive effect of Condurango 30C in ameliorating lung cancer through caspase-3-mediated apoptosis induction and EGFR down-regulation.

Thermotropic Liquid Crystal Polymer and PBT Blend

  • Lim, Sung-Tack;Kim, Seong-Hun
    • Proceedings of the Korean Fiber Society Conference
    • /
    • 1998.04a
    • /
    • pp.14-19
    • /
    • 1998
  • Increasing demand for high modulus high strength polymeric materials have drawn considerable interest in industry. Thermotropic liquid crystal polymers (TLCP), differing from lyotropic liquid crystal polymers, have excellent melt processability and mechanical property resulting from the high degree of molecular orientation under a shear flow field in the molten state with relatively low viscosity$\^$1,2/.(omitted)

  • PDF

Response characteristics and related material properties of modern LCDs for TV applications

  • Naemura, Shohei
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2005.07b
    • /
    • pp.1061-1066
    • /
    • 2005
  • Analytical solutions are obtained for the director reorientation dynamics of both VA and IPS modes by considering a possible effect of the molecular flow, providing a theoretical basis of the relations between the response characteristics of the display and the physical properties of the liquid crystal material used. The relevant properties of practical liquid crystal mixtures are quantitatively reviewed and the features of superior substances, used in formulating those mixtures, are presented.

  • PDF

Free molecule transmission probability of a conical tube with wall sorption

  • 인상렬
    • Journal of Korean Vacuum Science & Technology
    • /
    • v.2 no.1
    • /
    • pp.1-8
    • /
    • 1998
  • The uniform distributed pumping model is used to derive analytic expressions of the pressure profile for the molecular flow regime in linearly tapered or flared(conical or pyramidal) tubes with wall sorption. The concept of transmission conductance for sticky tubes of arbitrary shape is newly introduced to calculate the transmission probability using the pressure profile. The transmission probability obtained analytically for a conical sticky tube is compared with that from the Monte Carlo simulation.