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A Study about Reduction Method of the X-Ray Film Image (X선 사진의 감력법에 대한 실험 고찰)

  • Lee, Sang-Suk
    • Journal of radiological science and technology
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    • v.14 no.2
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    • pp.55-55
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    • 1991
  • I reduced overexposed X-Ray film image with farmer reduction method and $KMnO_4$ reduction method. The results are as follows : 1. In farmer reduction method, there appears linear decreasing film image density. 2. In $KMnO_4$ reduction method, there appears over proportional reduction. 3. When red prussiate is compared with $KMnO_4$ reduction method, the latter shows more intense reduction. 4. If the reduction solution isn't used within 10 minutes after dilution, it becomes oxidized and the ability is decreased remarkably.

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A Comparison Between Reduction Methods for BOD Loadings to Achieve Water Quality Standards at the End of the Yeongsan River (영산강 하류부의 목표수질 달성을 위한 BOD 부하량 삭감방법의 비교)

  • 황대호;정효준;이홍근
    • Journal of Environmental Health Sciences
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    • v.27 no.2
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    • pp.119-126
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    • 2001
  • The key point in establishing water quality management measures is how to decide the load reduction for pollution sources. This study was performed to compare reduction methods for BOD loadings to achieve water quality standards at the end of the Yeongsan river. The target year is 2006 and 2011 and reduction methods are uniform treatment and treatment by influence rate. Using QUAL2E model, the study was performed under the conditions of establishing and non-establishing the publicly owned treatment works(POTWs). Uniform treatment which allocate the same reduction rate to pollution sources showed that all streams into the river should be applied for the reduction. However, treatment by influence rate which allocate the reduction rate by the order of influence rate showed that achieving target quality might be possible with a few streams for the reduction. But total amount of load reduction of streams was not significantly different from two methods.

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Evaluation of Green House Gases (GHGs) Reduction Plan in Combination with Air Pollutants Reduction in Busan Metropolitan City in Korea

  • Cheong, Jang-Pyo;Kim, Chul-Han;Chang, Jae-Soo
    • Asian Journal of Atmospheric Environment
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    • v.5 no.4
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    • pp.228-236
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    • 2011
  • Since most Green House Gases (GHGs) and air pollutants are generated from the same sources, it will be cost-effective to develop a GHGs reduction plan in combination with simultaneous removal of air pollutants. However, effects on air pollutants reduction according to implementing any GHG abatement plans have been rarely studied. Reflecting simultaneous removal of air pollutants along with the GHGs emission reduction, this study investigated relative cost effectiveness among GHGs reduction action plans in Busan Metropolitan City. We employed the Data Envelopment Analysis (DEA), a methodology that evaluates relative efficiency of decision-making units (DMUs) producing multiple outputs with multiple inputs, for the investigation. Assigning each GHGs reduction action plan to a DMU, implementation cost of each GHGs reduction action plan to an input, and reduction potential of GHGs and air pollutants by each GHGs reduction action plan to an output, we calculated efficiency scores for each GHGs reduction action plan. When the simultaneous removal of air pollutants with the GHGs reduction were considered, green house supply-insulation improvement and intelligent transportation system (ITS) projects had high efficiency scores for cost-positive action plans. For cost-negative action plans, green start network formation and running, and daily car use control program had high efficiency scores. When only the GHGs reduction was considered, project priority orders based on efficiency scores were somewhat different from those when both the removal of air pollutants and GHGs reduction were considered at the same time. The expected action plan priority difference is attributed to great difference of air pollutants reduction potential according to types of energy sources to be reduced.

The Effect of Composition on Hydrogen Reduction Behavior of Ball-milled WO3-CuO Nanocomposite Powders (볼밀링한 WO3-CuO 나노복합분말의 조성에 따른 수소환원 거동)

  • Jung Sung-Soo;Kang Yun-Sung;Lee Jai-Sung
    • Journal of Korean Powder Metallurgy Institute
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    • v.13 no.3
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    • pp.205-210
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    • 2006
  • The effect of Cu content on hydrogen reduction behavior of ball-milled $WO_3$-CuO nanocomposite powders was investigated. Hydrogen reduction behavior and reduction percent(${\alpha}$) of nanopowders were characterized by thermogravimetry (TG) and hygrometry measurements. Activation energy for hydrogen reduction of $WO_3$ nanopowders with different Cu content was calculated at each heating rate and reduction percent(${\alpha}$). The activation energy for reduction of $WO_3$ obtained in this study existed in the ranging from 129 to 139 kJ/mol, which was in accordance with the activation energy for $WO_3$ powder reduction of conventional micron-sized.

A Study on Strategy for Embodiment of Low Carbon City (저탄소도시 구현을 위한 전략수립에 관한 연구)

  • Baek, Cheong-Hoon;Park, Sang-Hoon
    • Journal of The Korean Digital Architecture Interior Association
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    • v.11 no.2
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    • pp.83-92
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    • 2011
  • The purpose of this study is to propose strategies for reducing greenhouse gas emissions on urban areas. This study is made up GHG emission estimation and emission prospect methods, setting of GHG reduction target, GHG reduction plan formulation and feasibility assessment. The significance of this study is as follows. First, this study provides the local government for the overall frame of low carbon strategies. Second, this study contribute to establishment of GHG emission reduction strategies in the local autonomy by providing GHG emission estimation and setting reduction target which is essential elements of reduction strategy. Third, we organize a reduction element for low carbon city embodiment and showed the way to assessment the reduction effect of these elements quantitatively.

Power Frequency Magnetic Field Reduction Method for Residents in the Vicinity of Overhead Transmission Lines Using Passive Loop

  • Lee, Byeong-Yoon;Myung, Sung-Ho;Cho, Yeun-Gyu;Lee, Dong-Il;Lim, Yun-Seog;Lee, Sang-Yun
    • Journal of Electrical Engineering and Technology
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    • v.6 no.6
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    • pp.829-835
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    • 2011
  • A power frequency magnetic field reduction method using passive loop is presented. This method can be used to reduce magnetic fields generated within the restricted area near transmission lines by alternating current overhead transmission lines. A reduction algorithm is described and related equations for magnetic field reduction are explained. The proposed power frequency magnetic field reduction method is applied to a scaled-down transmission line model. The lateral distribution of reduction ratio between magnetic fields before and after passive loop installation is calculated to evaluate magnetic field reduction effects. Calculated results show that the passive loop can be used to cost-effectively reduce power frequency magnetic fields in the vicinity of transmission lines generated by overhead transmission lines, compared with other reduction methods, such as active loop, increase in transmission line height, and power transmission using underground cables.

DIESEL ENGINE NOx REDUCTION BY SNCR UNDER SIMULATED FLOW REACTOR CONDITIONS

  • Nam, Chang-Mo;Kwon, Gi-Hong;Mok, Young-Sun
    • Environmental Engineering Research
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    • v.11 no.3
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    • pp.149-155
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    • 2006
  • NOx reduction experiments were conducted by direct injection of urea into a diesel fueled, combustion-driven flow reactor which simulated a single engine cylinder ($966cm^3$). NOx reduction tests were carried out over a wide range of air/fuel ratios (A/F=20-40) using an initial NOx level of 530ppm, and for normalized stoichiometric ratios of reductant to NOx (NSR) of 1.5 to 4.0. The results show that effective NOx reduction with urea occurred over an injection temperature range of 1100 to 1350K. NOx reduction increased with increasing NSR values, and about a 40%-60% reduction of NOx was achieved with NSR=1.5-4.0. Most of the NOx reduction occurred within the cylinder and head section (residence time <40msec), since temperatures in the exhaust pipe were too low for additional NOx reduction. Relatively low NOx reduction is believed to be due to the existence of higher levels of CO and unburned hydrocarbons (UHC)inside the cylinder, and large temperature drops along the reactor. Injection of secondary combustible additives (diesel fuel/$C_2H_6$) into the exhaust pipe promoted further substantial NOx reduction (5%-30%) without shifting the temperature windows. Diesel fuel was found to enhance NOx reduction more than $C_2H_6$, and finally practical implications are further discussed.

A Qualitative Study on Risk Reduction Behaviors in Purchase Process of the Counterfeit of Fashion Luxury Brands - Focused on Risk Reduction Behaviors on Psychological Risk Perceptions -

  • Kim, Il
    • Journal of Fashion Business
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    • v.9 no.3
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    • pp.22-36
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    • 2005
  • This research is to classify psychological risk perceptions in purchases process at counterfeit at fashion luxury brands, into a risk perception on purchase activity itself and a risk perception on the post-purchase situation, and to analyze types and characteristics at risk reduction behaviors to reduce each risk perception. In this research a qualitative method was employed, and research-related data were collected and analyzed through in-depth interviews. Results were shown that risk reduction behaviors at psychological risk perception on purchase activity itself included rationalization of purchase, accompanied purchase, reduction and discontinuance of purchase, and that risk reduction behaviors of psychological risk perception on the post-purchase situation included information search, establishment of selection criteria, establishment of marginal limit, selective purchase, planned and compared purchase, and reduction and discontinuance of purchase. Previous researches suggested brand loyalty, selection of famous brands, utilization of information agents by marketers, pre-purchase usage and guaranteed purchase, but these risk reduction methods were not utilized, this probably being interpreted as a result of characteristics of counterfeit. In addition, risk reduction behavior of one type tended to reduce risk perception of several other types, and risk reduction behaviors of various types were utilized to reduce a certain type's risk perception. Not only types of risk perception but also levels of risk perception appeared to have exerted influence to risk reduction behaviors.

Hydrogen Reduction Behavior of Oxide Scale in Water-atomized Iron Powder (수분사 Fe 분말의 산화물 및 이의 수소가스 환원거동)

  • Shin, Hea-Min;Baik, Kyeong-Ho
    • Journal of Korean Powder Metallurgy Institute
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    • v.21 no.6
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    • pp.422-428
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    • 2014
  • In this study, the reduction kinetics and behaviors of oxides in the water-atomized iron powder have been evaluated as a function of temperature ranging $850-1000^{\circ}C$ in hydrogen environment, and compared to the reduction behaviors of individual iron oxides including $Fe_2O_3$, $Fe_3O_4$ and FeO. The water-atomized iron powder contained a significant amount of iron oxides, mainly $Fe_3O_4$ and FeO, which were formed as a partially-continuous surface layer and an inner inclusion. During hydrogen reduction, a significant weight loss in the iron powder occurred in the initial stage of 10 min by the reduction of surface oxides, and then further reduction underwent slowly with increasing time. A higher temperature in the hydrogen reduction promoted a high purity of iron powder, but no significant change in the reduction occurred above $950^{\circ}C$. Sequence reduction process by an alternating environment of hydrogen and inert gases effectively removed the oxide scale in the iron powder, which lowered reduction temperature and/or shortened reduction time.

A CLINICAL AND RADIOLOGICAL STUDY ON THE INTERNAL DERANGEMET OF TMJ (악관절 내장증의 임상 및 방사선학적 연구)

  • Han Won-Jeong;Kim Eun-Kyung
    • The Journal of Korean Academy of Maxillofacial Radiology
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    • v.22 no.2
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    • pp.351-364
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    • 1992
  • Internal derangement of the temporomandibular joint can be defined an abnormal relationships of the meniscus relative to the mandibular condyle, articuar fossa and eminence. This may cause variable mandibular dysfunctions and pain. For diagnosis, arthrography, computed tomography and magnetic resonance imaging are used. In this study, the author reviewed 98 TMJs of 88 patients who were diagnosed as internal derangement througth inferior joint space arthrography at the department of Oral & Maxillofacial Radiology, Dental Hospita, Dankook university through 1986 to 1992. 98 TMJs consisting of 30 disc displcement with reduction, 48 disc displcement without reduction and 20 perforation were studied about clinical and radiological findings. The results were as follows: 1. Internal derangement was found most frequently in the 2nd 3rd decades and the average age of perforation was higher than that of disc displcement with higher than that of disc displcement with reduction. The sexual predilection was 2 times hiher in females. 2. The most frequent chief complaints were TMJ sound in disc displcement with reduction, pain and limitation of mouth opening in disc displcement without reduction and pain in perforation. The duration of the chief complaints was longer in disc displcement with reduction with than in preforation and disc displcement without reduction. 3. Reciprocal click was the most frequently TMJ sound in disc displcement with reduction. History of joint sound in disc displcement without reduction an crepitus in perforation was the most frequent one. 4. The average maximum opening was 45.4㎜ in disc displcement with reduction, 31.4㎜ in disc displcement without reduction and 33.8㎜ in perforation. 5. In the centric occlusion, posterior condylar position was the most frequent in disc displcement with reduction. posterior and concentric condylar position was frequent in disc displcement without reduction, concentric and anterior condylar position in perforation. At 1 inch opening, the same position to articular eminence was most frequently found in disc displcement with reduction, posterior position in disc disp1cement without reduction, posterior and nterior position in perforation was frequently found. 6. Bony changes, especially sclerosis and flattening, was most frequently found in perforation.

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