• Title/Summary/Keyword: Final Reduction Rate

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A Study on the Variation of the Thermal Load for a House According to the Earth Sheltering Method (복토 주택의 복토 방법에 따른 열부하의 변화에 관한 연구)

  • Lee, Jae-Hyuk;Choi, Won-Ki;Suh, Seung-Jik;Cho, Dong-Woo
    • 한국태양에너지학회:학술대회논문집
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    • 2008.04a
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    • pp.166-171
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    • 2008
  • We cannot imagine any more the environment and energy problems are separated from our lives. The various attempts to solve these problems are made all over the world. In this study it was performed to analyze a different heating and cooling load depending on the earth-sheltering method and kind of soils by using TRNSYS 16 as the first step to establish the design guidelines for earth-sheltered architecture, one of the eco-friendly and low energy consuming building types. After performing this simulation, we found the result like this. It is the most lowest load in case of all of walls and roof being earth-sheltered. But considering of the load reduction rate, the effect of earth-sheltering the exterior vertical wall is more efficient for load reduction than the one of earth-sheltering a roof. And we got a lower thermal load in case of a lower heat conductivity of soil. Afterwards we will conduct a further study for boundary condition at earth-sheltered surface and the simulation analysis about the sensitivity variables. The final goal of this study is preparing the design guidelines for earth-sheltered architecture. so we will contribute to building energy saving.

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Electrochemical Studies of o-Cresolphthalexon at Mercury Electrode in Alkaline Media (염기성용액 중의 수은전극에서 o-Cresolphthalexon의 전기화학적 연구)

  • Chong-Min Pak;Sam-Woo Kang;Lee-Mi Do;Tae Yoon Eom;Ki-Suk Jung
    • Journal of the Korean Chemical Society
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    • v.35 no.2
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    • pp.158-164
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    • 1991
  • The reduction mechanism at a mercury electrode of o-cresolphthalexon(OCP) in strongly alkaline supporting electrolytes has been investigated by several electrochemical techniques. The radical formed after first one electron reduction uptake, dimerizes. The result of cyclic voltammetric investigation demonstrated the reversible nature of the electron transfer and standard rate constant was $3.27{\times}10^{-2}$ cm/sec. The apparent irreversible behavior of the second wave is a result of the existence of a fast protonation following the second electron transfer. At low concentration of OCP(< $1{\times}10^{-4}$M), cathodic current were remarkably adsorptive properties. Prolonged electrolysis was carried out at controlled potential of -1.85V, original violet color of the solution becames progressively weaker, and then colorless solution. The final product of an exhaustive electrolysis is electro-inactive. The appearence of four steps may be explained by the fact that the reduction of OCP elucidated ECEC mechanism.

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Selection of indigenous starter culture for safety and its effect on reduction of biogenic amine content in Moo som

  • Tangwatcharin, Pussadee;Nithisantawakhup, Jiraroj;Sorapukdee, Supaluk
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.10
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    • pp.1580-1590
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    • 2019
  • Objective: The aims of this study were to select one strain of Lactobacillus plantarum (L. plantarum) for a potential indigenous safe starter culture with low level antibiotic resistant and low biogenic amine production and evaluate its effect on biogenic amines reduction in Moo som. Methods: Three strains of indigenous L. plantarum starter culture (KL101, KL102, and KL103) were selected based on their safety including antibiotic resistance and decarboxylase activity, and fermentation property as compared with a commercial starter culture (L. plantarum TISIR543). Subsequently, the effect of the selected indigenous safe starter culture on biogenic amines formation during Moo som fermentation was studied. Results: KL102 and TISIR 543 were susceptible to penicillin G, tetracycline, chloramphenicol, erythromycin, gentamycin, streptomycin, vancomycin, ciprofloxacin and trimethoprim (MIC90 ranging from 0.25 to $4{\mu}g/mL$). All strains were negative amino acid-decarboxylase for lysis of biogenic amines in screening medium. For fermentation in Moo som broth, a relatively high maximum growth rate of KL102 and TISIR543 resulted in a generation time than in the other strains (p<0.05). These strain counts were constant during the end of fermentation. Similarly, KL102 or TISIR543 addition supported increases of lactic acid bacterial count and total acidity in Moo som fermentation. For biogenic amine reduction, tyramine, putrescine, histamine and spermine contents in Moo som decreased significantly by the addition KL102 during 1 d of fermentation (p<0.05). In final product, histamine, spermine and tryptamine contents in Moo som inoculated with KL102 were lower amount those with TISIR543 (p<0.05). Conclusion: KL102 was a suitable starter culture to reduce the biogenic amine formation in Moo som.

An Experimental Study on the Noise Reduction of Cooling Fans for Four-ton Forklift Machines (4톤급 지게차 냉각홴 소음 저감에 관한 실험적 연구)

  • Choi, Daesik;Kim, Seokwoo;Yeom, Taeyoung;Lee, Seungbae
    • Journal of Drive and Control
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    • v.18 no.1
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    • pp.1-8
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    • 2021
  • This paper presents research on methods for the reduction of forklifts' noise level for the increased comfort and safety of its operator. A cooling fan with a high air volume flow rate installed in the forklift acts as an important design parameter which efficiently cools the heat exchanger system, helping to transfer internal heat from the engine room to the outdoors with both transmitted and diffracted opening noises. The cooling fan contributes significantly to both the forklift's emitted sound power and the operator room's noise level, thereby necessitating research on the forklift's reduction of acoustic power level and transmission. A noise analysis for various fan models with a biomimetic design based on eagle-wing geometry was conducted. In addition to the acoustic power generation, the aerodynamic performance of the cooling blade is also strongly influenced by the design of airfoil distribution, thereby requiring optimization. The cooling fans were fabricated and installed in the forklift in order to check the efficacy of the forklift engine's cooling, and the final version of the fan was measured for its ability to lower acoustic power level and cool the engine room. This study explains the aerodynamic and acoustic features of the designed fans with the use of BEM analysis and forklift test results.

An Analysis of the Effect on Childbirth Will of Married Women (기혼여성의 출산의지에 영향을 미치는 요인 연구)

  • Lee, So-Young
    • Journal of Family Resource Management and Policy Review
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    • v.12 no.2
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    • pp.15-30
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    • 2008
  • According to the research taken by the National Statistical Office, the fertility rate of a Korean fertile female is 1.17. This figure is the lowest in the world, and the reduction in the fertility rate over the last 30 years was the biggest in the world. It can be seen as a warning alarm about the effects of a low birth rate and a silver society. Assuming that there are several factors involved in this phenomenon, this study inquired into the attitude towards children, attitude towards nourishing children, attitude towards sex roles and the harmony between the jobs and families of married females, and examined the factors that influence the willingness to give birth. Final 581 copies of the survey questionnaire were used for analysis and the collected data were analysed by SPSS, Pearson's correlation analysis, t-test, ANOVA, and Duncan's Multiple Range Test. Three main conclusions were reached: Firstly, the value variables, such as sex-role attitudes and the preference for work or home, affect the willingness to give birth. Therefore, it can be said that one's values have a significant effect on these variables and the willingness to give birth. Secondly, both working morns and housewives have a strong tendency to give a birth if they are supported on child rearing. Finally, the employment of the married women itself can be a variable that can affect childbirth. In other words, the working hours affect employed married women so as sex-role attitudes, the preference between work and home, ideal number of children, and the income to housewives. Also, even in whole married women, the employment itself can be a major factor of the willingness to have a baby. Therefore, unemployed married women have more of a tendency to have children than employed married women.

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Anatomical Direct Reduction of Bony Mallet Finger Using Modified-Intrafocal Pinning Technique (변형-내초점 핀 고정술을 이용한 골성 망치 수지의 해부학적 직접 정복)

  • Kang, Sang-Woo;Park, Ji-Kang;Jung, Ho-Seung;Cha, Jung-Kwon;Kim, Kook-Jong
    • Archives of Hand and Microsurgery
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    • v.23 no.4
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    • pp.248-253
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    • 2018
  • Purpose: The purpose of this study was to evaluate the clinical results of anatomic reduction of bony mallet finger using modified-intrafocal pinning technique. Methods: From March 2014 to October 2017, 18 patients with bony mallet finger were treated with modified-intrafocal pinning technique. Kirschner-wire was used to directly reduction the bony fragment, and extension block pinning and distal interphalangeal joint fixation were additionally performed to minimize the loss of reduction. Postoperative pain, range of motion, and radiological evaluation were performed. Duration of bone healing, functional recovery and complication rate were evaluated and Crawford's criteria was used to determine functional outcome after surgery. Results: Bone union was achieved in all cases after a postoperative mean of 6 weeks (5-7 weeks). An average of $2.8^{\circ}$ ($0^{\circ}-10^{\circ}$) extension loss occurred in all patients. All patients showed satisfactory joint congruency and reformation of the joint surface, the mean flexion angle of the distal interphalangeal joint at the final follow-up was $72.2^{\circ}$ ($70^{\circ}-75^{\circ}$). According to Crawford's classification, 12 patients (66.7%) were excellent and 6 patients (33.3%) were good. Conclusion: Modified-intrafocal pinning technique is a method of obtaining anatomical bone healing by directly reduction and fixation of the bony fragment. Combined with other conventional percutaneous pinning procedures, it is expected that good results can be obtained if applied to appropriate indications.

Acidification and Changes of Mineral Nutrient Availability in Soils Amended with Elemental Sulfur

  • Kim, Byoung-Ho;Chung, Jong-Bae
    • Korean Journal of Soil Science and Fertilizer
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    • v.44 no.1
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    • pp.22-28
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    • 2011
  • With the increasing cultivation of acid-loving plants such as blueberries, the artificial acidification of soils is frequently required. This research was conducted to determine the application rates of elemental sulfur (S) required in the soil acidification for blueberry cultivation. Laboratory incubation experiment was conducted to acidify three arable soils (pH 6-7) of different texture to pH 4.5-5.0 by the addition of varying amounts of elemental S. All rates of elemental S addition reduced soil pH, although the efficacy of acidification was related to the application rate and soil characteristics. pH reduction was slow in sandy loam soil, and the final equilibrium pH was obtained after 60, 43, and 30 days of incubation in sandy loam, loam, and silty clay, respectively. Although the final pHs obtained after 93 days of incubation were not significantly different among the three soils, the equilibrium pH was relatively higher in soil of higher clay content in the application rates of 1.5-2.0 g S $kg^{-1}$ soil. The estimated amounts of elemental S required in lowering pH to 4.5-5.0 were 0.59-1.01, 0.67-1.03, and 0.53-0.88 g S $kg^{-1}$ for sandy loam, loam, and silty clay, respectively. The lowest estimated amount of elemental S in the acidification of silty clay soil was attributable to the low organic matter content. For clay soils containing optimum level of organic matter, the application rates of elemental S should be much higher than those values estimated in this research. Soil acidification did not significantly increase the available concentrations of Ca, Mg and K. Extractable Cu and Zn was not greatly affected by the acidification, but extractable Fe, Mn, and Al in the acidified soils were higher than those found in non-acidified soils. Such increases in solubility are attributable to the dissolution of oxides and hydroxides of the elements.

Characterization of Heavy Metals Bioleaching from Fly Ash by a Sulfur-Oxidizing Bacterium Thiobacillus thiooxidans: Effect of Solid Concentrations (황산화세균 Thiobacillus thiooxidans에 의한 fly ash의 중금속 제거 특성:고형물 농도의 영향)

  • 조경숙;문희선;이인숙
    • Korean Journal of Environmental Biology
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    • v.17 no.2
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    • pp.183-190
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    • 1999
  • The bioleaching of heavy metals from fly ash was performed by Thiobacillus thiooxidans MET isolated from the enrichment culture of an anaerobically digested sludge. The effect of solid concentrations on the efficiency of metal leaching was studied in shaken flasks. In the range of solid concentrations 20 g.L­$^1$to 100 g.L­$^1$T. thiooxidans MET oxidized S$^{0}$ to sulfate without any lag period. The final pH of slurry solution was decreased to below pH 1, and the final oxide-redox potential (ORP) was increased to over 420 mV in the solid concentrations below 100 g.L­$^1$. However, the initial lag period of 4 to 8 days was required to obtain the pH reduction and ORP increase of the slurry solutions in the range of solid concentrations 150 g.L­$^1$to 300 g.L­$^1$. The sulfur oxidation rate of T. thiooxidans MET in 20~100 g.L­$^1$solid concentrations was 0.70~0.75 g-S.L­$^1$ㆍ d­$^1$, but its sulfur oxidation activity was remarkably inhibited with increasing solid concentration over 150 g.L­$^1$. Increasing fly ash solids concentration in the range of solids concentration 20 g.L­$^1$ to 200 g.L­$^1$decreased the removal efficiency of Zn, Cu, Mn, Cr and Pb. The solubilization of heavy metals from fly ash was strongly correlated with the pH value of slurry solution. When the pH of slurry solution was reduced to 3, the solubilization process of Zn, Cu and Mn started, and their solubilization efficiency of Zn, Cu and Mn was progressively increased below pH 2. However, the solubilization process of Cr and Pb started at pH 2.5 and 2.0, respectively.

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Removal of Organic Wax and Particles on Final Polished Wafer by Ozonated DI Water

  • Yi, Jae-Hwan;Lee, Seung-Ho;Kim, Tae-Gon;Lee, Gun-Ho;Choi, Eun-Suck;Park, Jin-Goo
    • Korean Journal of Materials Research
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    • v.18 no.6
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    • pp.307-312
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    • 2008
  • In this study, a new cleaning process with a low cost of ownership (CoO) was developed with ozonated DI water ($DIO_3$). An ozone concentration of 40 ppm at room temperature was used to remove organic wax film and particles. Wax residues thicker than $200\;{\AA}$ remained after only a commercial dewaxer treatment. A $DIO_3$ treatment in place of a dewaxer showed a low removal rate on a thick wax layer of $8000\;{\AA}$ due to the diffusion-limited reaction of ozone. A dewaxer was combined with a $DIO_3$ rinse to reduce the wax removal time and remove wax residue completely. Replacing DI rinse with the $DIO_3$ rinse resulted in a surface with a contact angle of less than $5^{\circ}$, which indicates no further cleaning steps would be required. The particle removal efficiency (PRE) was further improved by combining a SC-1 cleaning step with the $DIO_3$ rinsing process. A reduction in the process time was obtained by introducing $DIO_3$ cleaning with a dewaxing process.

Flocculating Activity and Dehydration Efficiency of Biopolymer Flocculant Biopol32 in Industrial Wastewater Treatment (생물고분자응집제 Biopol32의 산업폐수에 대한 응집활성 및 탈수효과)

  • Lee, Myoung Eun;Oh, Nara;Suh, Hyun-Hyo
    • Journal of Life Science
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    • v.29 no.3
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    • pp.362-368
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    • 2019
  • For the practical application and development of biopolymer flocculant Biopol32 produced by Pseudomonas sp. GP32, its flocculation effect on wastewater from food processing, slaughter houses, and the dyeing industry was investigated. In the food processing wastewater, Biopol32 led to a chemical oxygen demand (COD) reduction rate of 70% and a suspended solid (SS) removal rate of 49% at pH 6.0. In the slaughter house wastewater at pH 4.0, a COD reduction rate of 61% and SS removal rate of 91% were observed, and in the dyeing wastewater, the rates were 72% and 92%, respectively, at pH 5.0. The size of floc formed during the flocculation process was 10 mm at a final concentration of 20 ppm, and the dehydration efficiency was 62%. In both the bioflocculant Biopol32 group and a PAA synthetic flocculant group, optimal flocculant concentration that yielded the best overall dehydration efficiency was 20 ppm, and, at this concentration, the shortest filtration time to reach the natural critical moisture content of 78.1% was attained.