• Title/Summary/Keyword: reductions

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Dynamic Performance Enhancement of the Railway Plate Girder Bridge using the In-site Continuous Method (현장 연속화 기법을 통한 철도판형교의 동적성능향상)

  • Oh, Ji-Taek;Kim, Hyun-Min
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.774-782
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    • 2011
  • In-site Continuous Method to improve the dynamic performance of railway plater girder bridge was developed. In this study, the In-site Continuous Method in the existing railway plate girder bridge was applied. Comparison of the results obtained from the field experiment were presented. The reductions in vertical acceleration were shown to approximately 24.8%, 45.4% and 27.5% in case of the freight train, passenger train and express tilting train, respectively. The reductions of lateral acceleration were shown to approx. 31%, 39% and 15% in the previous case. In the vertical displacement, the reductions were shown to approx. 20%, 13% and 12.6%, respectively. Through this method, we expect the problem of the restriction in speed up of train to be solve.

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Characterization of Graphite Oxide Reduced by Thermal and/or Chemical Treatments

  • Kim, Jungsoo;Nam, Dae-Geun;Yeum, Jeong Hyun;Suh, Sungbu;Oh, Weontae
    • Transactions on Electrical and Electronic Materials
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    • v.16 no.5
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    • pp.274-279
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    • 2015
  • Reduced graphite oxides (rGOs) were prepared by the common graphite oxidation method and the subsequent reductions. The reduction of graphite oxides (GOs) was conducted chemically and/or thermally. To further reduce the as-prepared rGOs, GOs were treated with chemical/thermal reductions or thermal/chemical reductions, in which the reduction sequence was also considered. The structural changes of as-prepared rGOs, depending on reduction methods, were investigated by X-ray diffraction analyses, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. In addition, we discuss the structural change of the rGOs and their closely related physical and electrical properties, such as thermogravimetry, nitrogen adsorption isotherm, and sheet resistance.

Valuing Drinking Water Risk Reductions Using Experimental Market Method (실험시장접근법을 이용한 먹는 물 수질개선에 대한 지불의사 측정)

  • Eom, Young Sook
    • Environmental and Resource Economics Review
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    • v.9 no.4
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    • pp.747-771
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    • 2000
  • This paper reports the results of a study to elicit willingness to pay (WTP) for changes in health risks from exposure to As, Pb, THM in tap water using experimental market method. The experimental market method, compared with other non-market valuation methods, allows us to use incentive compatible demand revealing scheme, to acquire market-like experience through repetitive auctions, and to incorporate learning process by providing new information during the session. Participants seemed to utilize the objective risk information in a 'rational' manner, and to change their WTP bids accordingly. Moreover they were able to reduce the 'ambiguity' in risk perception processes when objective risk probabilities provided are quite different from their subjective perceptions. Nonetheless, anchoring effects appeared to be still persistent in spite of market-like experience and learning opportunity. And implicit values entailed by WTP bid/risk tradeoffs indicate a wide variation in values across alternative risk reductions and overrated responses to very small risk reductions.

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The Meaning of Sustainable Agriculture and its Policy Implications (지속적(持續的) 농업(農業)의 의의(意義)와 정책방향(政策方向))

  • Kim, Jai Hong
    • Korean Journal of Agricultural Science
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    • v.20 no.2
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    • pp.211-220
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    • 1993
  • Sustainable agriculture is a management system for ecological equilibrium and long-run productivity. Conversions from conventional to sustainable farming systems could have good effects on future generations' productivity and agricultural market opening in Korea. However, farmers are not willing to adopt sustainable farming system as because of farm income reductions, so government programs may be needed. Government programs should have research support for cost reductions, direct support for advocational livestock breedings and income security, and relative price changes for reducing agricultural chemicals.

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Evaluation of the Effects of e-PTFE Membrane Exposure on the GTR in the Mandubular Furcation Involvement (GTR치료시 e-PTFE 차단막의 노출에 따른 하악이개부의 치유효과)

  • Kim, Chong-Kwan;Kim, Joon-Il
    • Journal of Periodontal and Implant Science
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    • v.30 no.3
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    • pp.569-584
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    • 2000
  • In order to evaluate the effects of the early exposure of e-PTFE membrane on the periodontal regeneration, 21 cases of 21 patients diagnosed as the chronic adult periodontitis were evaluated. All were class II furcation involvement cases. The control group was composed of 7 cases treated only by the flap operation. 14 cases were treated by the e-PTFE membrane as the experimental group, the membranes of 7 cases were exposed more than 1mm during healing period, which were named as the experimental group I, and the others, experimental group II. Clinical parameters such as probing pocket depth, clinical attachment level, bone probing depth, and gingival recession were recorded before the treatment and 6 months after the treatment. The results were as follows. 1. Significant probing depth reductions were observed for all groups(p<0.05), but no group shows significantly greater reductions than another. 2. Significant clinical attachment gains were observed for the experimental group II(p<0.05), no significant gains were observed in the other groups. 3. Significant bone probing depth reductions were observed for the experimental group II(p<0.05), no significant reductions were observed in the other groups. 4. All but the experimental group II exhibited a significant increase in gingival recession(p<0.05). The result suggested that is case of the e-PTFE membrane is exposed, the result is similar to that of flap operation without membrane. Therefore selecting the proper treatment case, intricate surgical procedure and infection control are essential for minimizing the chance of membrane exposure and finally for the good treatment results.

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Estimation of Greenhouse Gas (GHG) Reductions from Bioenergy (Biogas, Biomass): A Case Study of South Korea (바이오에너지 (바이오가스, 바이오매스) 기술의 온실가스 감축산정: 국내를 대상으로)

  • Jung, Jaehyung;Kim, Kiman
    • Journal of Korean Society for Atmospheric Environment
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    • v.33 no.4
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    • pp.393-402
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    • 2017
  • In this study, greenhouse gas (GHG) reductions from bioenergy (biogas, biomass) have been estimated in Korea, 2015. This study for construction of reduction inventories as direct and indirect reduction sources was derived from IPCC 2006 guidelines for national greenhouse gas inventories, guidelines for local government greenhouse inventories published in 2016, also purchased electricity and steam indirect emission factors obtained from KPX, GIR respectively. As a result, the annual GHG reductions were estimated as $1,860,000tonCO_{2eq}$ accounting for 76.8% of direct reduction (scope 1) and 23.2% of indirect reduction (scope 2). Estimation of individual greenhouse gases (GHGs) from biogas appeared that $CO_2$, $CH_4$, $N_2O$ were $90,000tonCO_2$ (5.5%), $55,000tonCH_4$ (94.5%), $0.3tonN_2O$ (0.004%), respectively. In addition, biomass was $250,000tonCO_2$ (107%), $-300tonCH_4$ (-3.2%), $-33tonN_2O$ (-3.9%). For understanding the values of estimation method levels, field data (this study) appeared to be approximately 85.47% compared to installed capacity. In details, biogas and biomass resulting from field data showed to be 76%, 74% compared to installed capacity, respectively. In the comparison of this study and CDM project with GHG reduction unit per year installed capacity, this study showed as 42% level versus CDM project. Scenario analysis of GHG reductions potential from bioenergy was analyzed that generation efficiency, availability and cumulative distribution were significantly effective on reducing GHG.

Isaria sinclairii Extract Reduces Body Weight and Ameliorates Metabolic Abnormalities

  • Ahn, Mi-Young;Kim, Ji-Young;Han, Jae-Woong;Jee, Sang-Duck;Hwang, Jae-Sam;Cho, Sung-Ig;Yun, Eun-Young
    • International Journal of Industrial Entomology and Biomaterials
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    • v.14 no.2
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    • pp.121-126
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    • 2007
  • Obesity is a major risk factor for cardiovascular disease. In our case study using animal models for disease states such as obesity or hypertension, we found that, Isaria sinclairii remarkably reduced body weight and ameliorated metabolic abnormalities in Zucker and SHR rats. Genetically obese (fa/fa) Zucker rats were one animal model chosen for this study. Four groups of rats received a standard diet and were treated orally with the following test samples daily for 8 weeks: saline (negative control), ethanol extracts of I. sinclairii, hot water extract of I. sinclairii, or $Xenical^{(R)}$ (30 mg/kg, positive control). Mild reductions (6.3%) in body weight gain were observed in the groups treated with the hot water extract of I. sinclairii compared to the control after 8 weeks. Interestingly, organ weight was greatly reduced by this Dongchunghacho (I. sinclairii), in parallel with the mild reductions in body weight gain and reductions in abdominal fat (adipose tissue). Also observed was a 4.1 % decrease in the ratio of heart weight/body weight compared to the control group. As a hypertensive animal model, SHR (spontaneously hypertensive rat) and WKY (Wistar Kyoto) rats were also administered these extracts for one month. Treatment with the hot water extract of I. sinclairii caused greater reductions in body weight gain for the SHR group (10.9%) compared to the WKY group's (5.2%). Based on these results, I. sinclairii extracts contain selective action for anti-obesity activity, naturally occurring candidate for regulation of body weight increase, as demonstrated in the present study.

Anti-amnesic and Antioxidant Effect of Bunsimgieum (Fenxinqiyin) on Scopolamine-Induced Memory Impairment in Mice (Scopolamine 유발 기억력 손상 마우스 모델에서 분심기음의 항산화 및 기억력 감퇴 억제 효과)

  • Han, Da-Young;Yu, Ok-Cheol;Kim, Sang-Ho;Chung, Dae-kyoo
    • Journal of Oriental Neuropsychiatry
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    • v.30 no.3
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    • pp.221-235
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    • 2019
  • Objectives: The purpose of this study was to confirm the anti-amnesic effects of Bunsimgieum (BSGE) through its favorable acetylcholine (ACh) and, acetylcholinesterase (AChE) activity, choline acetyltransferase (ChAT) mRNA expressions, and antioxidant effect on scopolamine (Sco)-induced memory impairment in C57BL/6 mice. Methods: Six groups, a total of 20 intact or 100 Sco-induced mice were used in this study, based on their body weight. Half of each group underwent passive avoidance tests and the measurement of hippocampus AChE activity, ACh content, and ChAT mRNA expression, The remaining half of each group underwent a Morris water-maze test and antioxidant defense system measurement as well. Results: Significant reductions in the step-through latency times from the passive avoidance test and reductions in the escape latency times from the Morris water-maze test were observed with increases of hippocampal AChE activities and, reductions in ACh contents and ChAT mRNA expression in hippocampus, as a result of Sco intraperitoneal treatment, in this study. Additionally, the increases in cerebral cortical MDA levels and, reductions in GSH contents, SOD activities, and CAT activities were demonstrated in the Sco control mice compared with the intact vehicle control mice, respectively. However, 28 days of consecutive oral pre-treatment of BSGE hot water extracts of 400, 200, and 100 mg/kg, respectively, markedly and dose-dependently inhibited Sco treatment-related amnesia. Conclusions: The results demonstrate that the oral administration of BSGE hot water extracts reduces Sco-induced memory impairment, through preserving ACh, related to ChAT mRNA expressions, causes AChE inhibition, and enhances the cerebral antioxidant defense system.

Effects of Aerosolized Sanitizers of Different Droplet Sizes on Foodborne Pathogen Reduction

  • Kim, Young-Ho;Jo, Young-Jun;Kim, Yun-Ji;Koo, Min-Seon;Lee, Jong-Kyung;Oh, Se-Wook
    • Food Science and Biotechnology
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    • v.17 no.3
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    • pp.664-668
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    • 2008
  • The diffusivity of aerosol sanitizers may be determined by the weight and droplet size of the aerosol. To test the effects of droplet size, 2 types of aerosol sanitizers were prepared using different ultrasonic nebulizer frequencies (1.6 and 2.4 MHz) and their reduction activities were determined against Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella typhimurium. A sodium hypochlorite aerosol was treated for 10, 30, or 60 min in a model aerosol cabinet. When the aerosol prepared by nebulizing at 1.6 MHz was treated for 30 min, a 0.2 log reduction was observed in E. coli O157:H7 and 0.3 log reductions were exhibited in L. monocytogenes and S. typhimurium, respectively. After 60 min, the 3 pathogens were reduced by 1.7, 0.6, and 0.8 log units, respectively. However, when the aerosol prepared by nubulizing at 2.4 MHz was treated, the microbes presented 1.6, 0.5, and 0.6 log reductions at 30 min, and 1.8, 0.9, and 1.1 log reductions at 60 min of treatment, respectively.

Novel Approaches to Clubroot Management in Western Canada

  • Hwang, Sheau-Fang;Strelkov, Stephen E.
    • 한국균학회소식:학술대회논문집
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    • 2015.05a
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    • pp.49-49
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    • 2015
  • Over the past decade, clubroot has emerged as a major constraint to canola (Brassica napus) production in central Alberta, Canada. The number of fields with confirmed P. brassicae infestations in Alberta has increased steadily from 12 in 2003 to nearly 2,000 in 2014. Management of clubroot on canola has focused on sanitization of field equipment, soil amendments to reduce viable pathogen populations, long rotations out of susceptible crops and cropping of resistant cultivars. Clubroot resistance is the most effective and economical method of disease mitigation, but the recent identification of isolated P. brassicae populations with novel virulence phenotypes capable of overcoming resistance in most canola cultivars highlights the variable nature and adaptability of the pathogen. Recent studies have shown slight reductions in pathogen populations through crop rotations, but much more substantial reductions in spore populations in heavily infested areas near field entrances using fumigants such as Vapam (metam-sodium) or Basamid (dazomet). Greenhouse trials showed that seedling emergence, plant height and root weight increased, while primary and secondary infection and disease severity decreased with increased Basamid dosage. However, field trials showed some phytotoxicity. Application of Vapam at rates of 0.4 to $1.6mL\;L^{-1}$ soil resulted in 12-16 fold reductions in clubroot severity and primary and secondary infection. Vapam also was effective in reducing clubroot severity and improving canola seed yield under field conditions. These studies underscore the need for good resistance stewardship and for the integration of multiple products and practices for successful management of clubroot on canola.

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