• Title/Summary/Keyword: separation resistance

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A Study of the Hull Form of Oil Recovery Vessel by Using Magnetic Fluid (자성유체를 이용한 유회수선박의 선형연구)

  • 이귀주;박영식;김경화;노준혁;장희문
    • Journal of Ocean Engineering and Technology
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    • v.15 no.2
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    • pp.1-5
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    • 2001
  • A study on the new active type oil-water separation system including the oil-water separation system of magnetic film was carried out. Separation system is composed of several active types of circulating oil separation steps and one magnetic film separation step at final stage. At the magnetic separation step, ferrofluid easily forms a weak magnetic mixture with oil, which is from the water by magnetic field gradient. The vessel has been designed to run at the maximum speed of 25 knots. And two typical forms of SWATH and Catamaran have been studied as a new type of oil recovery vessel.

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The Finite Element Analysis and Experiment of Flexible Media Separation Mechanism (유연매체 분리기구의 유한요소해석과 실험)

  • Yoon, You-Hoon;Baek, Yoon-Kil;Yoon, Joon-Hyun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.322-325
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    • 2005
  • The separation mechanism is installed to separate a note one by one from the stacked notes and the overlap type, one of separation mechanism, has been used a lot in financial equipments like ATM. This paper has compared and estimated analysis results using finite element method with experimental results over various parameters such as conditions of note, overlap value, roller shapes, which affect the friction force (resistance) exerting on notes between rollers. Consequently, the effect of various parameters on the performance of overlap type separation mechanism can be known and optimal shape and overlap value can be obtained.

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Separation of PET and PS with Air Separation

  • Nakazawa, Hiroshi;Kudo, Yasuo;Sato, Hayato
    • Proceedings of the IEEK Conference
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    • 2001.10a
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    • pp.727-729
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    • 2001
  • The air separation of PET (Polyethylene terephthalate) and PS(Polystyrene) was carried out by taking advantage of the different abrasive resistance of two plastics. PET bottles and PS packages were shredded to small square pieces $(5{\times}5mm)$. Both plastic shreds were treated by a shear-type crusher. The PET shreds were bent and twisted by the crush so that they were blown up easily, but the PS shreds were not. After the crush of mixture of both plastics, air separation experiments were carried out using four types of air separators. The number and location of the baffle attached to them are different. With the separator with a baffle attached at the upper part, PET recoveries for the crushing time of 30, 60 and 90sec were 67, 98 and 99% respectably at the air flow rate of 3.5m/s, whereas PS recoveries were null regardless of the crushing time.

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Fabrication of Stable Water/Oil Separation Filter Using Effect of Surface Wettability (표면 젖음성을 이용한 물/오일 분리막 제작)

  • Kim, Dohyeong;An, Taechang
    • Journal of Sensor Science and Technology
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    • v.25 no.3
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    • pp.213-217
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    • 2016
  • The superhydrophobic and superoleophobic meshes surfaces have been used in various applications such as self-cleaning, anti-icing, gas exchange, oil-water separation, sound-wave penetrable anti-wetting structures, etc. In particular, there are many studies for oil-water separation with environmental issues. Because of high pressure and dynamic environment, oil-water separation filters must have stable surface properties as super-hydrophobicity and superoleophobicity. The oleophobicity of surface depends on the surface chemistry and roughness of the surface. The roughness of oleophobic surface enhances its static contact angle and stability. The multi-scale hierarchical structure provides a stable superhydrophobic state by maintaining a Cassie state. In this research, we fabricated a superoleophobic mesh with a multi-scale hierarchical structure to increase the pressure resistance and adjusted a size of the mesh hole.

Control of Nano-Structure of Ceramic Membrane and Its Application (세라믹 멤브레인의 나노구조 제어 및 응용)

  • Lee, Hye-Ryeon;Seo, Bong-Kuk;Choi, Yong-Jin
    • Membrane Journal
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    • v.22 no.2
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    • pp.77-94
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    • 2012
  • Amorphous ceramic membranes have been developed for gas phase separation and liquid phase separation (water treatment, wastewater treatment and separation of organic solvent or compounds) because of their thermal stability and solvent resistance. In this paper, ceramic membranes were categorized by membrane pore size and materials, and summarized for hydrogen separation, carbon dioxide separation, membrane reactor, pervaporation and water treatment with membrane structure and properties.

Research and Development Trends of Polyimide Based Material for Gas Separation (기체분리용 폴리이미드 소재의 연구개발동향)

  • Kim, Deuk Ju;Nam, Sang Yong
    • Membrane Journal
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    • v.23 no.6
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    • pp.393-408
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    • 2013
  • Gas separation processes using polymeric membranes have been greatly developed during the last few decades due to high energy efficiency and economic advantages. To achieve optimum economic performance, gas separation membranes required high permeability and selectivity. So, a number of reports examining the various polymeric materials for gas separation membranes have been published. Among the studied materials, polyimide (PI), which exhibit high permselectivity for various gas pairs, high chemical resistance, thermal stability, and mechanical strength, have attracted much attention. This paper focuses on the basic principle of gas separation, preparation procedure of membrane along with the recent developments and research trends of PI based materials for gas separation.

The Quality Assurance Technique of Resistance Spot Welding Pieces using Neuro-Fuzzy Algorithm (뉴로-퍼지 알고리즘을 이용한 점용접재의 강도추론 기술)

  • Kim, Joo-Seok;Choo, Youn-Joon;Lee, Sang-Ryong
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.10
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    • pp.141-151
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    • 1999
  • The resistance Spot Welding is widely used in the field of assembling the plates. However we don't still have any satisfactory solution, which is non-destructive quality evaluation in real-time or on-line, against it. Moreover, even though the rate of welding under the condition of expulsion has been high until now, quality control of welding against expulsion hasn't still been established. In this paper, it was proposed on the quality assurance technique of resistance spot welding pieces using Neuro-Fuzzy algorithm. Four parameters from electrode separation signal in the case of non-expulsion, and dynamic resistance patterns in the case of expulsion are selected as fuzzy input parameters. The parameters consist of Fuzzy Inference System are determined through Neuro-Learning algorithm. And then, fuzzy Inference System is constructed. It was confirmed that the fuzzy inference values of strength have within ${\pm}$4% error specimen in comparison with real strength for the total strength range, and the specimen percent having within ${\pm}$1% error was 88.8%. According to KS(Korean Industrial Standard), tensile-shear strength limit for electric coated of zinc is 400kgf/mm2. Judging to the quality of welding is good or bad, according to this criterion and the results of inference, the probability of misjudgement that good quality is valuated into poor one was 0.43%, on contrary it was 2.59%. Finally, the proposed Neuro-Fuzzy Inference System can infer the tensile-shear strength of resistance spot welding pieces with high performance for all cases-non-expulsion and expulsion. And On-Line Welding Quality Inspection System will be realized sooner or later.

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Effect of Mandibular Reposition on Airway Resistance (하악의 위치 변화가 기도저항에 미치는 영향)

  • 최재갑;정태훈
    • Journal of Oral Medicine and Pain
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    • v.23 no.1
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    • pp.65-73
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    • 1998
  • This study evaluated whether substantial airflow resistance changes occurred by changing jaw position in normal and snoring subjects. A case-control design was utilized to assess group differences. Subjects included 11 snoring patients and 10 non-snoring subjects. Airway resistance was assessed using a whole body plethysmograph. Subjects in this study had their mouth opening standardized to a position of 7 mm of vertical separation and the resistance was measured under the following conditions; normal jaw position and 2/3 maximum protrusive jaw position. The results were as follows : 1. The airway resistance was higher in snoring group than in non-snoring group. 2. Both groups had a significant decrease in their airflow resistance upon jaw protrusion. In conclusion, these data document that airflow resistance can be significantly influenced by jaw positioning. Moving the jaw in a protrusive position produced reduction of resistance.

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Numerical Simulation on the Performance of Axial Vane Type Gas-Liquid Separator with Different Guide Vane Structure

  • Yang, Fan;Liu, Ailan;Guo, Xueyan
    • International Journal of Fluid Machinery and Systems
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    • v.10 no.1
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    • pp.86-98
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    • 2017
  • In order to obtain high efficiency and low resistance droplet separation apparatus, axial vane type gas-liquid separators with different guide vanes were designed, and the RNG $k-{\varepsilon}$ model as well as discrete phase model (DPM) were used to investigate the flow pattern inside the separators. It was shown that the tangential velocity distribution under different guide vanes have Rankine vortex characteristics, pressure distribution exhibits a high similarity which value becomes big as the increase of the blade outlet angle and the decrease of the guide vane numbers. The increase of the guide vane numbers and the decrease of the blade outlet angle could make separation improve significantly. The separation efficiency is almost 100% when the droplet diameter is bigger than $40{\mu}m$.

Blast-load-induced interaction between adjacent multi-story buildings

  • Mahmoud, Sayed
    • Earthquakes and Structures
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    • v.17 no.1
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    • pp.17-29
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    • 2019
  • The present study aims to present a comprehensive understanding of the performance of neighboring multi-story buildings with different dynamic characteristics under blast loads. Two different scenarios are simulated in terms of explosion locations with respect to both buildings. To investigate the effect of interaction between the neighboring buildings in terms of the induced responses, the separation gap is set to be sufficiently small to ensure collisions between stories. An adequately large separation gap is set between the buildings to explore responses without collisions under the applied blast loads. Several blast loads with different peak pressure intensities are employed to perform the dynamic analysis. The finite-element toolbox Computer Aided Learning of the Finite-Element Method (CALFEM) is used to develop a MATLAB code to perform the simulation analysis. The dynamic responses obtained in the scenarios considered herein are presented comparatively. It is found that the obtained stories' responses are governed mainly by the location and intensity of the applied blast loads, separation distances, and flexibility of the attacked structures. Moreover, explosions near a light and flexible building may lead to a significant decrease in blast resistance because explosions severely influence the dynamic responses of the building's stories.