• Title/Summary/Keyword: film transfer system

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Absorption of Water Vapor into an Absorbing Binary Liquid Film Falling over a Horizontal Tube Bank (수평원관군상(水平圓管群上)의 이원흡수용액유동(二元吸收溶液流動)에 의(依)한 전달흡수특성(傳達吸收特性))

  • Kim, S.;Kim, Y.I.;Seo, S.C.;Hwang, D.K.
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.17 no.5
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    • pp.583-589
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    • 1988
  • Condensation of water vapor into an absorbent liquid of LiBr-water solution falling over a bank of water cooled horizontal tubes was investigated theoretically. The governing conservation equation for a re-defined physical transport phenomena were solved numerically using a finite difference method. Raw parameters were used in this study, since reliable experimental data is required prior to a dimensionless parametric study. The average values of wall heat transfer coefficient and interfacial absorption rate were defined to see the system performance. Other parameters include tube diameter, streamwise coordinate (and number of tubes in row), mass flow rate, and the wall temperature. The effects of these quantities on the absorption processes and suggestions for a rational system design have been presented.

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Effect of Si Addition on the Corrosion Resistance of CrN Coatings in a Deaerated $3.5wt.\%$ NaCl Solution (탈기된 $3.5wt.\%$ NaCl 용액 환경에서의 스테인리스 강에 증착된 CrN 박막의 Si 첨가에 따른 영향 평가)

  • Kim Woo-Jung;Choi Yoon-Seok;Kim Jung-Gu;Lee Ho-Young;Han Jeon-Gun
    • Journal of Surface Science and Engineering
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    • v.38 no.4
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    • pp.137-143
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    • 2005
  • CrSiN coatings of stepwise changing Si concentration were deposited on stainless steel by closed field unbalanced magnetron sputtering (CFUBM) system. Microstructure of the films due to the Si concentration is measured by XRD. The corrosion behavior of CrSiN coatings in deaerated $3.5\%$ NaCl solution was investigated by potentiodynamic test, electrochemical impedance spectroscopy (EIS) and surface analyses. The microstructure of CrSiN film depends on the Si concentration. When Si/(Cr+si) was under $11.7\%$, preferred orientation is defined at CrN(220), CrN(311) and $Cr_2N(111).$ The results of potentiodynamic polarization tests showed that the corrosion current density and porosity decreased with increasing Si/(Cr+si) ratio. EIS measurements showed that the corrosion resistance of Si-bearing CrN was improved by phase transformation of the film, which leads to increase of pore resistance and charge transfer resistance. At the Si(Cr+si) ratio of 20, the Si-bearing CrN possesses the best corrosion resistance due to the highest pore resistance and charge transfer resistance.

Image Quality Evaluation of Digital X-ray Image and Film Image using Contrast Method (Contrast Method를 이용한 디지털 X선 영상과 필름 영상의 영상 질(Quality) 평가)

  • Park, Ji-Koon;Jung, Bong-Jae;Choi, Jang-Yong;Kang, Sang-Sik
    • Journal of radiological science and technology
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    • v.34 no.1
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    • pp.9-15
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    • 2011
  • In this paper, an image quality evaluation of amorphous selenium based x-ray system was performed using modulation transfer function (MTF) measurement. MTF as a main factor of imaging quality evaluation was investigated by contrast method from acquired test pattern image. The MTF value was measured to 36.1% at 3.0 lp/mm which is twice as high as that in the film image. Compared with other studies, the results demonstrate that amorphous selenium based x-ray detector is clinically meaningful.

Design of Projection Optical System for Target Imaging Simulator with Long Exit Pupil Distance

  • Xueyuan Cao;Lingyun Wang;Guangxi Li;Ru Zheng
    • Current Optics and Photonics
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    • v.7 no.6
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    • pp.745-754
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    • 2023
  • In order to test the recognition ability and accuracy of a target imaging simulator under the irradiation of solar stray light in a laboratory environment, it needs to be fixed on a five-axis turntable during a hardware-in-the-loop simulation test, so the optical system of the simulator should have a long exit pupil distance. This article adopts a secondary imaging method to design a projection optical system suitable for thin-film-transistor liquid crystal displays. The exit pupil distance of the entire optical system is 1,000 mm, and the final optimization results in the 400 nm-850 nm band show that the modulation transfer function (MTF) of the optical system is greater than 0.8 at the cutoff frequency of 72 lp/mm, and the distortion of each field of view of the system is less than 0.04%. Combined with the design results of the optical system, TracePro software was used to model the optical system, and the simulation of the target imaging simulator at the magnitude of -1 to +6 Mv was analyzed and verified. The magnitude error is less than 0.2 Mv, and the irradiance uniformity of the exit pupil surface is greater than 90%, which meets the requirements of the target imaging simulator.

Study of an improved and novel venturi scrubber configuration for removal of radioactive gases from NPP containment air during severe accident

  • Farooq, Mujahid;Ahmed, Ammar;Qureshi, Kamran;Shah, Ajmal;Waheed, Khalid;Siddique, Waseem;Irfan, Naseem;Ahmad, Masroor;Farooq, Amjad
    • Nuclear Engineering and Technology
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    • v.54 no.9
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    • pp.3310-3316
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    • 2022
  • Owing to the rising concerns about the safety of nuclear power plants (NPP), it is essential to study the venturi scrubber in detail, which is a key component of the filtered containment venting system (FCVS). FCVS alleviates the pressurein containment byfiltering and venting out the contaminated air. Themain objective of this research was to perform a CFD investigation of different configurations of a circular, non-submerged, self-priming venturi scrubber to estimate and improve the performance in the removal of elemental iodine from the air. For benchmarking, a mass transfer model which is based on two-film theory was selected and validated by experimental data where an alkaline solution was considered as the scrubbing solution. This mass transfer model was modified and implemented on a unique formation of two self-priming venturi scrubbers in series. Euler-Euler method was used for two-phase modeling and the realizable K-ε model was used for capturing the turbulence. The obtained results showed a remarkable improvement in the removal of radioactive iodine from the air using a series combination of venturi scrubbers. The removal efficiency was improved at every single data point.

A study on the digital image transfer application mass chest X-ray system up-grade (간접촬영기의 디지털 영상 변환 장치 적용에 대한 연구)

  • Kim, Sun-Chil;Park, Jong-Sam;Lee, Jon-Il
    • Journal of radiological science and technology
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    • v.26 no.3
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    • pp.13-17
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    • 2003
  • By converting movable indirect mass chest X-ray devices for vehicles into digital systems and upgrading it to share information with the hospital's medical image information system, excellencies have been confirmed as a result of installing and running this type of system and are listed hereinafter. 1. Upgrading analog systems, such as indirect mass chest X-ray devices dependent on printed film, to digital systems allows them to be run and managed much more efficiently, contributing to the increase in the stability and the efficiency of the system. 2. Unlike existing images, communication based on DICOM standards allow images to be compatible with the hospital's outer and inner network PACS systems, extending the scope of the radiation departments information system. 3. Assuming chest-exclusive indirect mass chest X-rays, a linked development of CAD (Computer Aided Diagnosis, Detector) becomes possible. 4. By applying wireless Internet, Web-PACS for movable indirect mass chest X-ray devices for vehicles will become possible. Research in these fields must continue and if the superior image quality and convenience of digital systems are confirmed, I believe that the conversion of systems still dependent on analog images to modernized digital systems is a must.

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A Study of voluntary deliberation agency for resolving problems in film censorship (영화 심의 문제 해결을 위한 민간 자율 심의 기구의 필요성 모색)

  • Suh, Dae-Jeong
    • Journal of Digital Convergence
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    • v.12 no.12
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    • pp.537-544
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    • 2014
  • The film has far-reaching power than any other media. For this reason, a censorship has existed in some way but censorship is like a double-edged sword. If KMRB stood in front of a desire to preserve the morals of society and youth protection, creativity of artists must be shaken. On the contrary if free will is emphasized, social chaos will be increase. Thus most countries made various censorship systems in order to overcome this contradiction. In recent years, mainly on the issue of censorship and the rating is a tendency to transfer to the voluntary deliberation agency. However, this issue is still dealing with this problem at KMRB in Korea. Then KMRB mistakes itself as the guardian of situation ethics and morality. Recently various problems appeared in the film rating system. KMRB should be devolved on the voluntary deliberation agency in order to solve the problem. therefore this study The study will be to review the need for voluntary veliberation agency.

Heat Transfer Enhancement by the Perforated Plate of Round Impinging Air Jets (원형충돌제트에서 다공질판에 의한 열전달 향상)

  • Kim, Yun-Taek;Lee, Yeong-Min;Won, Se-Yeol;Lee, Dae-Hui
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.25 no.4
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    • pp.475-484
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    • 2001
  • The purpose of this study is to investigate the heat transfer augmentation using the perforated plate placed in front of a target plate in an axisymmetric impinging air jet system. The new liquid crystal technique using neural networks with median filtering is used to determine the Nusselt number distributions on the target surface. The experiments were made for the jet Reynolds number (Re) 23,000. The effects of the pitch-to-diameter (p/d1) from 1.5 to 2.5 in the perforated plate, the hole diameter on perforated plate (d1) from 4㎜ to 12㎜, the perforated plate to target surface distance (z/d1) from 1 to 3, and the nozzle-to-target surface distance (L/d) from 2 to 10 on the heat transfer characteristics were experimentally investigated. It was found that when the perforated plate was located between the nozzle exit and the target plate, the average heat transfer rate at the stagnation region corresponding to r/d$\leq$1.0 was increased up to the maximum 2.3 times compared to the case without the perforated plate.

A Study on Weight Transfer Sidehill Slopes during Goal Impact : Especially sidehill Slopes with ball above the feet (측면경사면에서의 목표 타격시 체중이동에 관한 연구 : 오르막경사를 중심으로)

  • Lee, Eui-Lin;Choi, Ji-Young
    • Korean Journal of Applied Biomechanics
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    • v.16 no.1
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    • pp.43-53
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    • 2006
  • Among several movements that occurred upon a slope, golf swing is the most typical one because environmental conditions dynamically vary with many kinds of slopes. Some studies on the golf swing were performed about a weight transfer on flatland, however, there couldn't be seen any study about the weight transfer on slope elsewhere. Therefore, the purpose of this study was to provide quantified data to objectively test the coaching words and keys about the weight transfer at sidehill slope during goal impact EspeciaIly sidehill Slopes with ball above the feet. Four highschool golfer, who have average handy 5, were recruited for this study. Plantar pressure distribution and cinematographic data were collected during golf swing in the conditions of flatland, $5^{\circ}$, $10^{\circ}$ and $15^{\circ}$sidehill slope simultaneously. The two data were used to synchronize the two data later. The plantar regions under the foot were divided into 8 regions according to the directly applied pressure pattern of the subject to insole sensor. The 8 foot regions were hullux, medial forefoot, central forefoot, lateral forefoot, medial midfoot, lateral midfoot, medial heel, and lateral heel. And the plantar pressure data was also divided into four movement address, phases-backswing. downswing, and follow-through phases according to the percentage shown to the visual information of film data. Based on the investigations on public golf books and experiences of golfers, it was hypothesized by the authors in the early of this study that the steeper slopes are, the more weight loads on left foot that positions at the higher place. When observing the results of plantar pressure and vertical force curves according to the sidehill slope conditions, the hypothesis could be accepted.

Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2013 (설비공학 분야의 최근 연구 동향 : 2013년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.26 no.12
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    • pp.605-619
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    • 2014
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2013. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and relative parts including orifices, dampers and ducts, fuel cells and power plants, cooling and air-conditioning, heat and mass transfer, two phase flow, and the flow around buildings and structures. Research issues dealing with home appliances, flows around buildings, nuclear power plant, and manufacturing processes are newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for general analytical model for desiccant wheels, the effects of water absorption on the thermal conductivity of insulation materials, thermal properties of Octadecane/xGnP shape-stabilized phase change materials and $CO_2$ and $CO_2$-Hydrate mixture, effect of ground source heat pump system, the heat flux meter location for the performance test of a refrigerator vacuum insulation panel, a parallel flow evaporator for a heat pump dryer, the condensation risk assessment of vacuum multi-layer glass and triple glass, optimization of a forced convection type PCM refrigeration module, surface temperature sensor using fluorescent nanoporous thin film. In the area of pool boiling and condensing heat transfer, researches on ammonia inside horizontal smooth small tube, R1234yf on various enhanced surfaces, HFC32/HFC152a on a plain surface, spray cooling up to critical heat flux on a low-fin enhanced surface were actively carried out. In the area of industrial heat exchangers, researches on a fin tube type adsorber, the mass-transfer kinetics of a fin-tube-type adsorption bed, fin-and-tube heat exchangers having sine wave fins and oval tubes, louvered fin heat exchanger were performed. (3) In the field of refrigeration, studies are categorized into three groups namely refrigeration cycle, refrigerant and modeling and control. In the category of refrigeration cycle, studies were focused on the enhancement or optimization of experimental or commercial systems including a R410a VRF(Various Refrigerant Flow) heat pump, a R134a 2-stage screw heat pump and a R134a double-heat source automotive air-conditioner system. In the category of refrigerant, studies were carried out for the application of alternative refrigerants or refrigeration technologies including $CO_2$ water heaters, a R1234yf automotive air-conditioner, a R436b water cooler and a thermoelectric refrigerator. In the category of modeling and control, theoretical and experimental studies were carried out to predict the performance of various thermal and control systems including the long-term energy analysis of a geo-thermal heat pump system coupled to cast-in-place energy piles, the dynamic simulation of a water heater-coupled hybrid heat pump and the numerical simulation of an integral optimum regulating controller for a system heat pump. (4) In building mechanical system research fields, twenty one studies were conducted to achieve effective design of the mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, and renewable energies in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment is mostly focused on indoor environment and building energy. The main researches of indoor environment are related to infiltration, ventilation, leak flow and airtightness performance in residential building. The subjects of building energy are worked on energy saving, operation method and optimum operation of building energy systems. The remained studies are related to the special facility such as cleanroom, internet data center and biosafety laboratory. water supply and drain system, defining standard input variables of BIM (Building Information Modeling) for facility management system, estimating capability and providing operation guidelines of subway station as shelter for refuge and evaluation of pollutant emissions from furniture-like products.