• Title/Summary/Keyword: composite control

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Optimal Condition of Operation Parameter for Livestock Carcass Leachate using Fenton Oxidation Process (가축 사체 매몰지 침출수 처리를 위한 Fenton 산화공정의 최적조건)

  • An, Sang-Woo;Jeong, Young-Cheol;Yoo, Ji-Young;Min, Jee-Eun;Lee, Si-Jin;Park, Jae-Woo
    • Journal of Soil and Groundwater Environment
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    • v.18 no.1
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    • pp.26-35
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    • 2013
  • Outbreak of animal infectious diseases such as foot-and-mouth disease, avian influenza are becoming prevalent worldwide. For prevent the further infection, tremendous numbers of the infected or culled stocks are buried around farm. This burial method can generate a wide range of detrimental components such as leachate, nutrient, salt, and pathogenic bacteria, consequently. In this study, for the stabilization of livestock carcasses leachate, advanced oxidation processes utilizing the Fenton reaction was investigated in lab-scale experiments for the treatment for $COD_{Cr}$ of livestock carcass leachate. $COD_{Cr}$ reduction by the Fenton oxidation was investigated response surface methodology using the Box-Begnken methods were applied to the experimental results. A central composite design was used to investigate the effects of the independent variables of pH ($x_1$), dosage of $FeCl_2{\cdot}4H_2O$ ($x_2$) and dosage of $H_2O_2$ ($x_3$) on the dependent variables $COD_{Cr}$ concentration ($y_1$). A 1 M NaOH and $H_2SO_4$ was using for pH control, $FeCl_2{\cdot}4H_2O$ was used as iron catalyst and NaOH was used for Fenton reaction. The optimal conditions for Fenton oxidation process were determined: pH, dosage of $FeCl_2{\cdot}4H_2O$ and dosage of $H_2O_2$ were 3, 0.6 g (0.0151 M) and 7 mL(0.259 M), respectively. Statistical results showed the order of significance of the independent variables to be pH > initial concentration of ferrous ion > initial concentration of hydrogen peroxide.

Characterization and Process Optimization of Cookies Prepared with Steamed Liriopis tuber Extract Using Response Surface Methodology (증숙 맥문동을 첨가한 쿠키의 품질 특성 및 제조조건 최적화)

  • Lee, Hyun Jung;Kim, Minji;Lee, Seoyoun;Kim, Doohyun;Kim, Won Baek;Park, So Hae;Lee, Heeseob
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.3
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    • pp.381-388
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    • 2017
  • This study was performed to evaluate the effects of Liriopis tuber (SLT) extracts on cookie production conditions for reduction of sugar usage through response surface methodology (RSM). The experimental conditions were designed according to the central composite design with 17 experimental points, including three replicates for three independent variables such as the amounts of SLT extracts, butter, and sugar. The experimental data on quality and sensory evaluation of cookies were fitted with various models, and accuracy of the equations was analyzed by ANOVA. Among various responses, spread ratio, sugar content, lightness, redness, hardness, and sensory properties of color, texture, sweetness, appearance, and overall quality showed significant correlations with the contents of three independent variables. From these results, the optimum formulation of cookies for reduced usage of sugar was calculated as SLT extract 6.84 g, butter 47.20 g, and sugar 36.02 g. Optimized cookies showed improved sensory properties but no difference in sweetness compared to control cookies.

Optimal Condition of TOC Removal Parameter for Sewage Effluent using Electrolysis Process (하수방류수 내 TOC 제거를 위한 전기분해공정의 최적 조건)

  • An, Sang-Woo;Jung, Hyuk-Sang;Lee, Hui-Kyung;Ko, Jun-Geol;Myoung, Dae-Won
    • Journal of the Korean GEO-environmental Society
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    • v.18 no.4
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    • pp.23-29
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    • 2017
  • As the Enforcement Ordinance of Environmental Policy Act was revised in 2013, Total Organic Carbon (TOC) was added as an indicative parameter for organic matter in Water and Aquatic Ecosystem Environmental Criteria. Under these imminent circumstances, a regulatory standard is needed to achieve the proposed TOC limitation control water quality from the STP (Sewage Treatment Plant). In this study, a electrolysis utilizing the electrochemical reaction was investigated in lab-scale experiments for the treatment of TOC in sewage effluent. TOC reduction by a electrolysis was investigated response surface methodology using the Box-Begnken methods were applied to the experimental results. A central composite design was used to investigate the effects of the independent variables of electrode space ($x_1$), current density ($x_2$) and electrolyte concentration ($x_3$) on the dependent variables removal efficiency of TOC (y). The optimal conditions for electrolysis were determined: electrode space, current density and electrolyte concentration were 50 mm, $10.3mA/cm^2$ and 0.1M, respectively. Statistical results showed the order of significance of the independent variables to be electrode space > current density > electrolyte concentration.

Suggestion of the Settlement Estimation Method for Granular Compaction files Considering Lateral Deformations (횡방향 변형을 고려한 조립토 다짐말뚝의 침하량 평가기법 제안)

  • Hwang Jung-Soon;Kim Hong-Taek;Kim Seung-Wook;Koh Yong-Il
    • Journal of the Korean Geotechnical Society
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    • v.21 no.3
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    • pp.149-157
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    • 2005
  • In cases of the loosely accumulated ground and soft clayey soils, the settlement criterion usually governs in evaluating the stability of structures. The settlement is also a dominant factor to control the design of granular compaction piles mainly applied to the reinforcement of foundation structures in soft ground. In the previous studies, settlement behaviors of granular compaction piles have generally been analyzed with an evaluation of the settlement reduction factor based on the load-sharing ratio and the replacement ratio. In this approach, however, since the reinforced ground with granular compaction piles is simplified as the composite ground, only the difference of a relative vertical strength between piles and soils is taken into account without reflecting lateral behaviors of granular compaction piles. In the present study, the method of estimating the settlement of granular compaction piles is proposed by synthetically considering a vertical strength of the ground, lateral behaviors of granular compaction piles, the strength of pile materials, a pile diameter, and an installation distance of the pile. Further, far the verification of a validity of the proposed method, predicted settlements are compared with results from previous studies. In addition, parametric studies are performed together with detailed analyses of relevant design parameters.

Accuracy Evaluation of Composite Hybrid Surface Rainfall (HSR) Using KMA Weather Radar Network (기상청 기상레이더 관측망을 이용한 합성 하이브리드 고도면 강우량(HSR)의 정확도 검증)

  • Lyu, Geunsu;Jung, Sung-Hwa;Oh, Young-a;Park, Hong-Mok;Lee, GyuWon
    • Journal of the Korean earth science society
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    • v.38 no.7
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    • pp.496-510
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    • 2017
  • This study presents a new nationwide quantitative precipitation estimation (QPE) based on the hybrid surface rainfall (HSR) technique using the weather radar network of Korea Meteorological Administration (KMA). This new nationwide HSR is characterized by the synthesis of reflectivity at the hybrid surface that is not affected by ground clutter, beam blockage, non-meteorological echoes, and bright band. The nationwide HSR is classified into static (STATIC) and dynamic HSR (DYNAMIC) mosaic depending on employing a quality control process, which is based on the fuzzy logic approach for single-polarization radar and the spatial texture technique for dual-polarization radar. The STATIC and DYNAMIC were evaluated by comparing with official and operational radar rainfall mosaic (MOSAIC) of KMA for 10 rainfall events from May to October 2014. The correlation coefficients within the block region of STATIC, DYNAMIC and MOSAIC are 0.52, 0.78, and 0.69, respectively, and their mean relative errors are 34.08, 30.08, and 40.71%.

Fluoride Release and Recharge Properties of Several Fluoride-Containing Restorative Materials (수종의 불소함유 수복재의 불소 유리 및 재충전)

  • Lee, Dongyun;Kim, Jongsoo;Han, Miran;Shin, Jisun
    • Journal of the korean academy of Pediatric Dentistry
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    • v.47 no.2
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    • pp.196-204
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    • 2020
  • The aim of the study is to compare the fluoride release and recharge properties of glass ionomer cements and 'alkasite'. Specimens of two glass ionomer cements (Fuji IX GP and Riva Self Cure), 'alkasite' restorative material (Cention N) and composite resin (Filtek™ Z350XT) were prepared. The fluoride release of each specimen was measured for 28 days. Thereafter, 1.23% acidulated phosphate fluoride (APF) gel was applied to experimental groups. No treatment was performed on control groups. The fluoride release was measured for additional 7 days to evaluate the fluoride recharge properties of each materials. The fluoride release was highest in Riva Self Cure, followed by Fuji IX GP, Cention N (p < 0.05). Fluoride release of Cention N was measured to be approximately 49% of Fuji IX GP's. After the application of 1.23% APF gel, increases in fluoride release were observed in Riva Self Cure, Fuji IX GP and Cention N (p < 0.05). Fluoride recharge was observed in Cention N as well as in glass ionomer cements. Further studies are required to evaluate the anti-cariogenic properties of Cention N at clinical conditions.

Characteristics of Wheat Flour Dough and Noodles with Barnyard Millet (Echinochloa spp.) (식용피 첨가에 의한 밀가루 반죽 및 국수의 특성)

  • Lee, Yun Sang;Yoon, Hyang-Sik;Lee, Sang-Yeong;Lee, Joung-Kwan;Park, Chul Soo;Seo, Woo Duck;Woo, Sun-Hee;Song, In Gyu
    • The Korean Journal of Food And Nutrition
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    • v.25 no.4
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    • pp.706-712
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    • 2012
  • The effects of barnyard millet (Echinochloa spp.) content (10~30%) on wheat flour dough and noodle properties were investigated. As the amount of barnyard millet increased, the particle size and ash content of mixed flour increased, while lightness tended to decrease. The gelatinization characteristics of millet flour showed higher peak viscosity, holding strength, final viscosity, and setback compared with wheat flour. There was significant positive correlation between protein content and sedimentation volume, as well as between protein content and water absorption. As the amount of barnyard millet increased, hardness, springiness and cohesiveness of wet noodles tended to decrease. From the results of sensory evaluation, composite flours (addition up to 20% barnyard millet) were rated with a quality score for taste and overall acceptance which was comparable with the control flour.

Development of Graphene Nanocomposite Membrane Using Layer-by-layer Technique for Desalination (다층박막적층법을 이용한 담수화용 그래핀 나노복합체 분리막 개발)

  • Yu, Hye-Weon;Song, Jun-Ho;Kim, Chang-Min;Yang, Euntae;Kim, In S.
    • Membrane Journal
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    • v.28 no.1
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    • pp.75-82
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    • 2018
  • Forward osmosis (FO) desalination system has been highlighted to improve the energy efficiency and drive down the carbon footprint of current reverse osmosis (RO) desalination technology. To improve the trade-off between water flux and salt rejection of thin film composite (TFC) desalination membrane, thin film nanocomposite membranes (TFN), in which nanomaterials as a filler are embeded within a polymeric matrix, are being explored to tailor the separation performance and add new functionality to membranes for water purification applications. The objective of this article is to develop a graphene nanocomposite membrane with high performance of water selective permeability (high water flux, high salt rejection, and low reverse solute diffusion) as a next-generation FO desalination membrane. For advances in fabrication of graphene oxide (GO) membranes, layer-by-layer (LBL) technique was used to control the desirable structure, alignment, and chemical functionality that can lead to ultrahigh-permeability membranes due to highly selective transport of water molecules. In this study, the GO nanocomposite membrane fabricated by LBL dip coating method showed high water flux ($J_w/{\Delta}{\pi}=2.51LMH/bar$), water selectivity ($J_w/J_s=8.3L/g$), and salt rejection (99.5%) as well as high stability in aqueous solution and under FO operation condition.

Experimental Study for the Bending Behavior of Precast Concrete Panel and Composite Deck for Railway Bridge (철도교 바닥판용 프리캐스트 패널과 합성 바닥판의 휨거동에 대한 실험적 연구)

  • Seol, Dae-Ho;Lee, Kyoung-Chan;Youn, Seok-Goo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.3
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    • pp.21-31
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    • 2018
  • This paper presents an experimental investigation on the structural performance of precast ribbed panel specimens and bridge deck specimens fabricated from the panels. The panel specimens are developed for permanent deck forms of railway bridges (PSC girder). The decks of railway bridges have short lengths compared with highway bridges. Therefore, precast panels for railway bridges are different from those of highway bridges. The precast panels have ribs designed for crack control at the bottom of the sections. Two kinds of specimens were examined: one with 400-mm width and one with 1200-mm width. Three specimens of each type were fabricated, and a total of 12 specimens were tested. In this test, the ultimate load, strain of the reinforcement and concrete, crack width, deformation, and slip were measured. The structural performance of the specimens was assessed using the Korea railway bridge design code and Eurocode. All specimens met the current design criteria for structural strength and serviceability.

Design and Safety Control in Construction Stage of Prestressed Concrete Box Girder Bridge with Corrugated Steel Web (파형강판 PSC 박스거더 교량의 설계 및 시공중 안전관리)

  • Kim, Kwang-Soo
    • Journal of the Korean Society of Safety
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    • v.23 no.2
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    • pp.87-97
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    • 2008
  • The Ilsun Bridge is the world's longest box girder bridge(801m) with corrugated steel webs and has the widest width($21.2{\sim}30.9m$: tri-cellular cross section) among these kinds of composite girder bridges. It has fourteen spans(50m, 10 at 60m, 50m, 2 at 50.5m) where twelve spans are erected by the incremental launching method and two spans by full staging method. Special topics related to the structural safety of prestressed concrete box girder bridge with corrugated steel web in construction stage and service were reviewed. Investigations focus on the span-to-depth ratio, shear stress of corrugated steel webs and optimization of tile length of steel launching nose. The span-to-depth ratio of Ilsun bridge has been found to be well-planned while the corrugated steel web has been designed highly conservative and it has been observed that the conventional nose-deck interaction equation do not fit well with corrugated steel web bridges. As a result, detailed construction stage analysis was performed to check the stress levels and the safety of preceding design conditions. Finally, from the design review of Ilsun bridge, this study suggests optimal design issues which should be of interest in designing a prestressed concrete box girder bridge with corrugated steel webs.