• Title/Summary/Keyword: reduction effect

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Effect of Cobalt Oxide on Carbothermal Reduction of Spray Dried Titanium-Cobalt-Oxygen Based Oxide Powder (분무건조법에 의해 제조된 Ti-Co-O계 산화물 분말의 환원/침탄반응에 미치는 코발트 산화물의 영향)

  • Lee, Gil-Geun;Kim, Chan-Young
    • Journal of Powder Materials
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    • v.12 no.5 s.52
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    • pp.336-344
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    • 2005
  • In the present study, the focus is on the effect of cobalt oxide powder in the carbothermal reduction of the titanium-cobalt-oxygen based oxide powder by solid carbon for the optimizing synthesis process of ultra fine TiC/Co composite powder. The titanium-cobalt-oxygen based oxide powder was prepared by the combination of the spray drying and desalting processes using the titanium dioxide powder and cobalt nitrate as the raw materials. The titanium-cobalt-oxygen based oxide powder was mixed with carbon black, and then this mixture was carbothermally reduced under flowing argon atmosphere. Changes in the phase structure and thermal gravity of the mixture during carbothermal reduction were analysed using XRD and TGA. Titanium-cobalt-oxygen based oxide powder desalted at $600^{\circ}C$ had a mixture of $TiO_2\;and\;Co_{3}O_4$. And the one desalted at $800^{\circ}C$ had a mixture of $TiO_2\;and\;CoTiO_3$. In the case of the former powder, the reduction of cobalt oxide powder in the titanium-cobalt-oxygen based oxide powder occurred at lower temperature than the latter one. However, the carbothermal reduction of titanium dioxide powder in the titanium-cobalt-oxygen based oxide powder with a mixture of $TiO_2\;and\;Co_{3}O_4$ occurred at higher temperature than the one with a mixture of $TiO_2\;and\;CoTiO_3$. And also, the former powder showed a lower TiC formation ability than the latter one.

A Clinical Study on the Effect of 41 Obesity Patients through Yu$\'{e}$biji$\~{a}$sh$\`{u}$-t$\~{a}$ng with Low-Glycemic Diet (월비가출탕(越婢加朮湯)과 저당지수식이요법을 병행한 비만환자 41례에 관한 임상관찰)

  • Lee, Young-Seok;Cho, Sung-Woo;Lee, In-Seon
    • Korean Journal of Oriental Medicine
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    • v.17 no.2
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    • pp.173-181
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    • 2011
  • Objective : The purpose of this study is to evaluate the effect of Yuebijiashu-tang with Low-Glycemic Diet on the obesity and to improve the oriental medical methods of treatment in obesity patients. Methods : Forty one patients were classified into four groups(Normal, Overweight, 1st Obesity, 2nd Obesity) by Body Mass Index(BMI). Weight, Body Fat Mass, Body Fat Rate, Waist Hip Rate, BMI and Obesity Index were compared in each group by t-test. Results : In distribution of sex, male was 7(17.1%), female was 34(82.9%). Mean age was 37${\pm}$11 and the patients in twenties were the most. Among four groups, the number of 1st obesity groups was the most. In the change of body composition, the reduction of weight was 6.82${\pm}$2.67kg, the reduction of body fat mass was 5.53${\pm}$2.30kg, the reduction of BMI was $2.51{\pm}0.85kg/m^2$, the reduction of body fat rate was 4.61${\pm}$2.17%, the reduction of waist hip rate was 0.019${\pm}$0.013. Conclusion : This study shows that Yu$\'{e}$biji$\~{a}$sh$\`{u}$-t$\~{a}$ng with low-glycemic diet is effective on weight reduction.

On the Weight Reduction of Longitudinal Members of Mid-Sized Bulk Carrier Considering the Minimum Shear Force according to Compartment Arrangement based on H-CSR (구획배치에 따른 최소 전단력을 고려한 H-CSR 기반 중형 살물선 종강도 부재의 중량 절감 방안 연구)

  • Na, Seung-Soo;Song, Ha-Cheol;Jeong, Sol;Park, Min-Cheol;Bae, Sang-Don
    • Journal of the Society of Naval Architects of Korea
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    • v.54 no.4
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    • pp.352-359
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    • 2017
  • Because the Energy Efficiency Design Index(EEDI) came into effect in 2013, it is necessary to develop a new technology to overcome $CO_2$ emission regulations. In structural design viewpoint, lots of researches are carried out to develop eco-friendly and high fuel efficiency ships by weight reduction. By using the automated compartment arrangement system and automated structural design algorithm which were developed by the authors, new researches are performing to combine the above two systems. However, the effect of weight reduction was not significant because structural designs by using these systems for the midship part was carried out only focused on the minimum still water bending moment. In this paper, at first, good compartment arrangements which give the minimum still water bending moment and(or) shear force were chosen by using the automated compartment system. And then, influence of shear force on weight reduction was investigated by using the automated structural design algorithm considering longitudinal strength, local strength and shear strength of longitudinal members in cargo holds. Conclusively, it is necessary to consider the minimum still water bending moment and shear force simultaneously to reduce the weight of mid-sized bulk carrier. Also, good compartment arrangement which gives much more weight reduction compared with existing ship was proposed.

The Effect of Volume Reduction on Computed Treatment Planning during Head and Neck IMRT and VMAT (두경부 IMRT 및 VMAT 시 체적 감소가 전산화치료계획에 미치는 영향)

  • Ki-Cheon Um;Gha-Jung Kim;Geum-Mun Back
    • Journal of radiological science and technology
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    • v.46 no.3
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    • pp.239-246
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    • 2023
  • In this study, we assessed the effect of reduction of tumor volume in the head and neck cancer by using RANDO phantom in Static Intensity-Modulated Radiation Therapy (S-IMRT) and Volumetric-Modulated Arc Therapy (VMAT) planning. RANDO phantom's body and protruding volumes were delineated by using Contour menu of Eclipse™ (Varian Medical System, Inc., Version 15.6, USA) treatment planning system. Inner margins of 2 mm to 10 mm from protruding volumes of the reference were applied to generate the parameters of reduced volume. In addition, target volume and Organ at Risk (OAR) volumes were delineated. S-IMRT plan and VMAT plan were designed in reference. These plans were assigned in the reduced volumes and dose was calculated in reduced volumes using preset Monitor unit (MU). Dose Volume Histogram (DVH) was generated to evaluate treatment planning. Conformity Index (CI) and R2 in reference S-IMRT were 0.983 and 0.015, respectively. There was no significant relationship between CI and the reduced volume. Homogeneity Index (HI) and R2 were 0.092 and 0.960, respectively. The HI increased when volume reduced. In reference VMAT, CI and R2 were 0.992 and 0.259, respectively. There was no relationship between the volume reduction and CI. On the other hand, HI and R2 were 0.078 and 0.895, respectively. The value of HI increased when the volume reduced. There was significant difference (p<0.05) between parameters (Dmean and Dmax) of normal organs of S-IMRT and VMAT except brain stem. Volume reduction affected the CI, HI and OAR dose. In the future, additional studies are necessary to incorporate the reduction of the volume in the clinical setting.

Assessment of the Particulate Matter Reduction Potential of Climbing Plants on Green Walls for Air Quality Management

  • Jeong, Na Ra;Kim, Jeong-Hee;Han, Seung Won;Kim, Jong-Cheol;Kim, Woo Young
    • Journal of People, Plants, and Environment
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    • v.24 no.4
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    • pp.377-387
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    • 2021
  • Background and objective: To improve air quality, particulate matter (PM) can be reduced using green infrastructure. Therefore, in this study, we aimed to determine the particulate matter reduction potential of climbing plants used for green walls, an element of vertical green infrastructure. Methods: A sealed chamber with controlled environmental variables was used to assess the PM reduction level caused by climbing plants. PM concentration in the plant chamber was measured after two and four hours of PM exposure, and the reduction potential was assessed based on the leaf area. Results: Compared to the empty chamber (Control), the PM reduction speed per hour was higher in the plant chamber, which confirmed that climbing plants contribute to the reduction of PM in the air. The PM reduction speed immediately after exposure in the plant chamber was high, but this slowed over time. Additionally, PM has been continuously reduced in plants with large leaves. As a result of calculating the particulate matter reduction level based on leaf area, it was found that there was a difference by particle size. Actinidia arguta, Parthenocissus tricuspidata, Trachelospermum asiaticum, and Euonymus fortunei var. radicans showed a high reduction effect. The trichomes on the leaf surface of Trachelospermum asiaticum were found to affect PM reduction. Conclusion: PM adsorption on the leaf surface is an important factor in reducing its concentration. It was possible to compare different plants by quantifying the amount of PM reduction during a fixed time period. These results can be used as the basic data to select the plant species suitable for urban green walls in terms of PM reduction.

Effect of High Temperature Treatment and Subsequent Oxidation anil Reduction on Powder Property of Simulated Spent Fuel

  • Song, Kun-Woo;Kim, Young-Ho;Kim, Bong-Goo;Lee, Jung-Won;Kim, Han-Soo;Yang, Myung-Seung;Park, Hyun-Soo
    • Nuclear Engineering and Technology
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    • v.28 no.4
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    • pp.366-372
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    • 1996
  • The simulated spent PWR fuel pellet which is corresponding to the turnup of 33,000 MWD/MTU is prepared by adding 11 fission-product elements to UO$_2$. The simulated spent fuel pellet is treated at 40$0^{\circ}C$ in air (oxidation), at 110$0^{\circ}C$ in air (high-temperature treatment), and at $600^{\circ}C$ in hydrogen (reduction). The product is treated through additional addition and reduction up to 3 cycles. Pellets are completely pulverized by the first oxidation, and the high-temperature treatment causes particle and crystallite to grow and surface to be smooth, and thus particle size significantly increases and surface area decreases. The reduction following the high-temperature treatment decreases much the particle size by means of the formation of intercrystalline cracks. The particle size decreases a little during the second oxidation and reduction cycle and then remains nearly constant during the third and fourth cycles. Surface area of pounder increases progressively with the repetition of oxidation and reduction cycles, mainly due to the formation of Surface cracks. The degradation of surface area resulting from high-temperature treatment is restored by too subsequent resulting oxidation and reduction cycles.

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A Study on CIETEC Arbitration Case for the Relationship between Damages and Reduction under CISG (CISG상 손해배상과 대금감액의 관계에 관한 중국 CIETAC의 중재사례 연구)

  • Song, Soo-Ryun
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.51
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    • pp.133-158
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    • 2011
  • The purpose of this study is to analyze one of CIETEC(China International Economic and Trade Arbitration Commission) Award on the dispute arising from Cotton Sale Contact which deals with damages and reduction of the price. Especially this case focused on the effect of reduction of the price to damages. The purpose of damages is to place the aggrieved party in as good a position as if the other party had properly performed the contract. So court costs and attorney's fee should be regarded as the loss, because these are caused by consequence of the breach which is recoverable. With the same reason, overpaid taxes should also regard as the loss. It is not impossible, however, to claim both damages and reduction of the price for same loss at the same time. It means buyer could not claim damages for the same loss, once he already claimed reduction of the price. So Korean companies should consider which remedy is proper to himself under the circumstances. He should choose reduction of the price when market price is down. In case of rising market price, he should consider follows: first, it is better to choose damages based on current price(Art.76), if upswing of non-conformity price is higher then upswing of market price. Second, it is better to choose general rule for measuring damages(Art.74), if upswing of market price is higher then upswing of non-conformity price.

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Traffic Noise Reduction of Sunken Squares (썬큰광장의 교통소음 감쇠 효과)

  • Min Jang-Ki;Chang Tai-Hyun;Jung Jae-Man
    • Journal of the Korean Institute of Landscape Architecture
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    • v.32 no.5
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    • pp.35-42
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    • 2004
  • This study examines the traffic noise reduction effects of the diverse efficiency features of a sunken square, and investigates the reduction effects and characteristics of noise alterations according to the construction conditions in order to verify its possibility as a new noise reduction facility. The measured data were analyzed. As a result, (1) the traffic noise from the roads around the sunken squares exceeded the regulatory standards; (2) the sunken squares were protected from noise; (3) the sunken spaces yielded a greater reduction by 6∼7dB than the flat ground thanks to the diffraction effect; and (4) there were fine changes to noise according to the conditions of space construction. In short, a sunken square has the potential to afford new applications as a noise reduction facility in a highly concentrated downtown with the existing defects solved. In addition, its use for effective noise control is evident based on the noise characteristics of a space. Future studies need to include efforts to provide clearer quantitative data, as well as research on shape, layout, and materials.

Effects of Natural Organic Matter (NOM) on Cr(Ⅵ) reduction by Fe(II) (Fe(II)을 이용한 Cr(Ⅵ) 환원시 천연유기물의 영향)

  • 한인섭
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 1999.10a
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    • pp.81-84
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    • 1999
  • The aqueous geochemical characteristics of Cr(III) and Cr(Ⅵ) in environmental systems are very different from one another: Cr(Ⅵ) is highly soluble, mobile and toxic relative to Cr(III) Reduction of Cr(Ⅵ) to Cr(III) are beneficial in aquatic systems because of the transformation of a highly mobile and toxic species to one having a low solubility in water, thus simultaneously decreasing chromium mobility and toxicity. Fe(II) species are excellent reductants for transforming Cr(Ⅵ) to Cr(III), and in addition, keeping Cr(III) concentrations below the drinking water standard of 52 ppb at pH values between 5 and 11. Investigations of the effects of NOM on Cr(Ⅵ) reduction are for examining the feasibility of using ferrous iron to reduce hexavalent chromium in subsurface environments. Experiments in the presence of soils, however, showed that the solid phase consumes some of the reducing capacity of Fe(II) and makes the overall reduction kinetics slower. The soil components bring about consumption of the ferrous iron reductant. Particular attention is devoted to the complexation of Fe(II) by NOM and the subsequent effect on Cr(Ⅵ) reduction. Cr(Ⅵ) reduction rate by Fe(II) was affected by the presence of NOM (humic acid), The effects of humic acid was different from the solution pH values and the concentration of humic acid. It was probably due to the reactions between humic acid and Cr(Ⅵ), humic acid and Fe(II), and between Cr(Ⅵ) and Fe(II), at each pH.

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The Effect of an Oxidation Precatalyst on the $NO_x$ Reduction by $NH_3$-SCR Process in Diesel Exhaust ($NH_3$-SCR 방법에 의한 디젤 배기 내 De-$NO_x$ 과정에서의 DOC에 의한 영향과 저감 성능 변화)

  • Jung, Seung-Chai;Yoon, Woong-Sup
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.5
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    • pp.68-76
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    • 2008
  • Diesel $NO_x$ reduction by $NH_3$-SCR in conjunction with the effective oxidation precatalyst was analytically investigated. Physicochemical processes in regard to $NH_3$-SCR $NO_x$ reduction and catalytic NO-$NO_2$ conversion are formulated with detailed descriptions on the commanding reactions. A unified model is correctly validated with experimental data in terms of extents of $NO_x$ reduction by SCR and NO-$NO_2$ conversion by DOC. The present deterministic model based on the rate expressions of Langmuir-Hinshelwood reaction scheme finds a conversion extent directly. A series of numerical experiments concomitant with parametric analysis of the $NO_x$ reduction was conducted. $NO_x$ reduction is promoted in proportion to DOC volume ar lower temperatures and an opposite holds at lower space velocity and intermediate temperatures. $NO_x$ conversion is weakly correlated to the space velocity and the DOC volume at higher exhaust temperature. In DOC-SCR system, the $NO_x$ reduction efficiency depends on the $NH_3/NO_x$ ratio.