• Title/Summary/Keyword: Surface treatment system

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NUMERICAL STUDY ON THE CHARACTERISTICS OF NON-NEWTONIAN FLUID FLOW OVER OBSTACLE (장애물 주위의 비뉴턴 유체의 유동특성에 관한 수치적 연구)

  • Kim, Hyung Min
    • Journal of computational fluids engineering
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    • v.19 no.4
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    • pp.61-67
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    • 2014
  • Since the most of the existing non-Newtonian models are not adequate to apply to the lattmce Boltzmann method, it is a challenging task from both the theoretical and the numerical points of view. In this research the hydro-kinetic model was modified and applied to the 3-D moving sphere in the circular channel flow and the characteristics of the shear thinning effect by the HK-model was evaluated and the condition of ${\Gamma}$ in the model was suggested for the stable simulation to generate non-trivial prediction in three dimension strong shear flows. On the wall boundaries of circular channel the curved wall surface treatment with constant velocity condition was applied and the bounceback condition was applied on the sphere wall to simulate the relative motion of the sphere. The condition is adequate at the less blockage than 0.7 but It may need to apply a multi-scale concept of grid refinement at the narrow flow region. to obtain the stable numerical results.

Interfacial and Nondestructive Evaluation of Single Carbon Fiber/Epoxy Composites by Fiber Fracture Source Location using Acoustic Emission (Acoustic Emission 의 섬유파단 Source Location을 이용한 Carbon Fiber/Epoxy Composites의 계면특성 및 비파괴적 평가)

  • Kong, Jin-Woo;Kim, Jin-Won;Park, Joung-Man;Yoon, Dong-Jin
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2001.10a
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    • pp.116-120
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    • 2001
  • Fiber fracture is one of the dominant failure phenomena to determine total mechanical properties in composites. Fiber fracture locations were measured by optical microscopic method and acoustic emission (AE) as functions of matrix toughness and surface treatment by the electrodeposition (ED), and then two methods were compared. Two AE sensors were attached on the epoxy specimen and fiber fracture signals were detected with elapsed time. The interfacial shear stress (IFSS) was measured using tensile fragmentation test and AE system. In ED-treated case, the number of the fiber fracture measured by an optical method and AE was more than that of the untreated case. The signal number measured by AE were rather smaller than the number of fragments measured by optical method, since some fiber fracture signals were lost while AE detection. However, one-to-one correspondence between the x-position location by AE and real break positions by optical method was generally established well. The fiber break source location using AE can be a valuable method to measure IFSS for semi- or nontransparent matrix composites nondestructively (NDT).

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A Simple Syntax for Complex Semantics

  • Lee, Kiyong
    • Proceedings of the Korean Society for Language and Information Conference
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    • 2002.02a
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    • pp.2-27
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    • 2002
  • As pact of a long-ranged project that aims at establishing database-theoretic semantics as a model of computational semantics, this presentation focuses on the development of a syntactic component for processing strings of words or sentences to construct semantic data structures. For design arid modeling purposes, the present treatment will be restricted to the analysis of some problematic constructions of Korean involving semi-free word order, conjunction arid temporal anchoring, and adnominal modification and antecedent binding. The present work heavily relies on Hausser's (1999, 2000) SLIM theory for language that is based on surface compositionality, time-linearity arid two other conditions on natural language processing. Time-linear syntax for natural language has been shown to be conceptually simple and computationally efficient. The associated semantics is complex, however, because it must deal with situated language involving interactive multi-agents. Nevertheless, by processing input word strings in a time-linear mode, the syntax cart incrementally construct the necessary semantic structures for relevant queries and valid inferences. The fragment of Korean syntax will be implemented in Malaga, a C-type implementation language that was enriched for both programming and debugging purposes arid that was particluarly made suitable for implementing in Left-Associative Grammar. This presentation will show how the system of syntactic rules with constraining subrules processes Korean sentences in a step-by-step time-linear manner to incrementally construct semantic data structures that mainly specify relations with their argument, temporal, and binding structures.

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Dyeing Properties of CDP fiber( II ) - Effect of Heat Setting on Dyeing and Physical Properties of CDP Fabric - (CDP 섬유의 염색성(II) - 염색성 및 물성에 미치는 열처리의 영향 -)

  • Shin Woo Young;Jeong Dong Seok;Lee Mun Cheul
    • Textile Coloration and Finishing
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    • v.17 no.3 s.82
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    • pp.8-15
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    • 2005
  • Cationic dyeable polyester(CDP) fabric was annealed at varying temperatures range from $120^{\circ}C$ to $220^{\circ}C$ for 1, 3, and 5 min under tension. Dyeing rates of CDP fabrics were measured with cationic and disperse dyes at $100^{\circ}C$ and $120^{\circ}C$ in water system. Also X-ray diffraction pattern, DSC thermograms and dyeability of fabric with cationic and disperse dyes were investigated. The intensities of X-ray diffraction peaks of annealed fabric were increased with increasing in annealed temperature, and peak became sharp with heat setting temperature. The apparent color depth (K/S) of CDP fabric initially decreased with increase of heat-setting temperature up to $160\~180^{\circ}C$ and then increased at higher temperature. The shearing modulus(G) and surface roughness were increased with annealing temperature.

Low Molecular Weight Organic Acids in Brassica pekinensis Rupr. and Growing soil Influenced by Simulated Nitrate Deposition

  • Xie, Wen-Ming;Liu, Xing-Quan;Ko, Kwang-Yong;Lee, Kyu-Seung
    • Korean Journal of Environmental Agriculture
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    • v.27 no.3
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    • pp.279-284
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    • 2008
  • We investigated whether carboxylate exudation of Brassica pekinensis Rupr. was affected by nitrate deposition from simulated acid rain. A gas chromatographic (GC) analysis was employed for the determination of low molecular weight organic acids (LOA) in rhizosphere soils, bulk soil, roots and leaves of Brassica pekinensis Rupr.. Rhizosphere soils were collected after 8 weeks of plant growth by first removing the bulk soil from the root system and then by mechanical move off the rhizosphere soil that adhered to the root surface with soft brush. Soil and plant materials were simultaneously extracted with the mixture of methanol and sulfuric acid (100:7, v/v). Seven organic acids, oxalic, malonic, fumaric, succinic, maleic, L-malic and citric acid were identified and quantified by GC equipped with FID. Oxalic, L-malic, and citric acids were found in both the bulk and rhizosphere soils, while most LOAs were not detected in the control treatment. On the contrary, except maleic acid, all other organic acids were detected in the leaves and roots of cabbages treated with nitrate deposition.

Organic fouling in forward osmosis (FO): Membrane flux behavior and foulant quantification

  • Xia, Shengji;Yao, Lijuan;Yang, Ruilin;Zhou, Yumin
    • Membrane and Water Treatment
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    • v.6 no.2
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    • pp.161-172
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    • 2015
  • Forward osmosis (FO) is an emerging membrane technology with potential applications in desalination and wastewater reclamation. The osmotic pressure gradient across the FO membrane is used to generate water flux. In this study, flux performance and foulant deposition on the FO membrane were systematically investigated with a co-current cross-flow membrane system. Sodium alginate (SA), bovine serum albumin (BSA) and tannic acid (TA) were used as model foulants. Organics adsorbed on the membrane were peeled off via oscillation and characterized by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). When an initial flux of $8.42L/m^2h$ was applied, both flux reduction and foulant deposition were slight for the feed solution containing BSA and TA. In comparison, flux reduction and foulant deposition were much more severe for the feed solution containing SA, as a distinct SA cake-layer was formed on the membrane surface and played a crucial role in membrane fouling. In addition, as the initial SA concentration increased in FS, the thickness of the cake-layer increased remarkably, and the membrane fouling became more severe.

A study on the alteration of general characteristics and therapeutic effect of GamiYeoldahansotang(加味熱多寒少湯) in patients with Atopic Dermatitis (가미열다한소탕(加味熱多寒少湯) 투여후 아토피 피부염 환자의 임상상 변화에 대한 연구)

  • Jung Hwan-Su;Lee Jin-Yong
    • The Journal of Pediatrics of Korean Medicine
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    • v.15 no.2
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    • pp.177-188
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    • 2001
  • Background : Atopic Dermatitis is thought to be a common and chronic relapsing inflammatory skin disease that probably results from allergic reaction. Because it make some serious problems in children, it is needed to treat and at least subside symptoms. Objective : The aim of this study was to evaluate the efficacy of GamiYeoldahansotang(加味熱多寒少湯) for treating Atopic Dermatitis and survey the general characteristics in children with Atopic Dermatitis. Method : Atopic Dermatitis with typical clinical symptoms were included in this study. Forty two patients were treated with hot water extract of GamiYeoldahansotang(加味熱多寒少湯) for four weeks. Clinical evaluation were made by Jacob T scoring system before and after treatment. Total Serum IgE, Eosinophil count were also conducted. Results : Reduction in body surface area was not observed. But significant reductions of severity scores before and after adminstration of GamiYeoldahansotang(加味熱多寒少湯) were observed in all of three groups: mind, moderate, severe. specially severe intensity group was very statistically significant.(p<0.05) Conclusion : We speculate that GamiYeoldahansotang(加味熱多寒少湯) has some therapeutic effects in mitigating the symptoms of Atopic Dermatitis.

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Field Experiments Using In Situ Bioremediation to Treat Trichloroethylene (TCE)-Contaminated Groundwater

  • Goltz, Mark N.;Gandhi, Rahul K.;Gorelick, Steven M.;Hopkins, Gary D.;McCarty, Perry L.
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2001.04a
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    • pp.261-266
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    • 2001
  • Three innovative technologies to remediate trichloroethylene (TCE) in situ were (or currently are being) evaluated at a TCE-contaminated groundwater site at Edwards Air Force Base (AFB), California. The three technologies all make use of groundwater recirculation to obviate the need to pump contaminated groundwater to the surface fer treatment. The first technology, which implements aerobic cometabolic bioremediation to destroy TCE in situ, successfully reduced dissolved TCE concentrations from above 1 mg/L to 20-30 $\mu\textrm{g}$/L. The second technology, in-well vapor stripping (IWVS), is capable of treating dissolved TCE at concentrations in the tens to hundreds of mg/L. Finally, the third technology, bioenhanced in-well vapor stripping (BEHIVS): is a combination of the first two technologies, and is designed to reduce very high levels of TCE (tens to hundreds of mg/L) to concentrations that meet regulatory requirements 5 $\mu\textrm{g}$/L). Results of field evaluations of tile first two technologies are presented, and the design of the BEHIVS system. as well as model predictions of BEHIVS performance and the current status of the technology field evaluation. is discussed.

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Industrial dairy wastewater purification by shear-enhanced membrane filtration: The effects of vibration

  • Kertesz, Szabolcs
    • Membrane and Water Treatment
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    • v.5 no.2
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    • pp.73-86
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    • 2014
  • Membrane fouling is a major challenge limiting the use of membrane applications. In this study high induced shear rates were utilized at the membrane surface in order to reduce the organic and inorganic scaling by using the torsional vibration of flat sheet membranes. The performances of a vibratory shear-enhanced processing (VSEP) system for the ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) membrane filtration of industrial dairy wastewater were investigated. The vibration and non-vibration methods were compared with the same membrane and operational parameters during the purification of real dairy industrial process wastewater. In the initial experiments, short-term tests were carried out in which the effects of vibration amplitude, recirculation flow rate and transmembrane pressure were measured and compared. The permeate flux, turbidity, conductivity and chemical oxygen demand (COD) reduction of dairy wastewater were investigated by using UF, NF and RO membranes with vibration and non-vibration methods. In the subsequent experiments, concentration tests were also carried out. Finally, scanning electron microscopy (SEM) revealed that the vibration method gave a better performance, which can be attributed to the higher membrane shear rate, which reduces the concentration of solids at the membrane, and the transmission.

Development of Horizontal Boring Equipment for Radial Collector Wells (방사형 집수정을 위한 수평천공장치 개발)

  • Park, Geun-Wu;Jeong, Gyeong-Hwan;Lee, Chung-Hun;Kwon, June-Yong;Kim, Jae-Hwan
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.905-913
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    • 2008
  • The water resource depending on mostly surface water has many problems, such as contaminated and unpredicted contamination event. For this reason, it has been employed highly technical treatment method for them, such as ground water dam and river bank filtration. it has been developed the radial collector wells in kind of bank filtration to increase efficiency for in-taking the water resource insead of the vertical well needed many wells to take more resource. But it has many problems with the incumbent method to bore the horizontal hole for radial collector wells, such as filling with the filter material outside of a strainer by watering, jamming as retrieving the casing tube with the filter material, eccentric boring etc. To reduce the problems of incumbent equipment, it has been developed the horizontal boring equipment and performed the field trial tests several times, which have bits and water jetting system with rotating the cone-shaped front to be excavated easily. In this paper, it was compared the brand-new with the incumbent non-rotating pressing insertion method. Also it was shown the problems of the incumbent method was reduced effectively.

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