• Title, Summary, Keyword: mixing ratio

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Effects of Volatile Solid Concentration and Mixing Ratio on Hydrogen Production by Co-Digesting Molasses Wastewater and Sewage Sludge

  • Lee, Jung-Yeol;Wee, Daehyun;Cho, Kyung-Suk
    • Journal of Microbiology and Biotechnology
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    • v.24 no.11
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    • pp.1542-1550
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    • 2014
  • Co-digesting molasses wastewater and sewage sludge was evaluated for hydrogen production by response surface methodology (RSM). Batch experiments in accordance with various dilution ratios (40- to 5-fold) and waste mixing composition ratios (100:0, 80:20, 60:40, 40:60, 20:80, and 0:100, on a volume basis) were conducted. Volatile solid (VS) concentration strongly affected the hydrogen production rate and yield compared with the waste mixing ratio. The specific hydrogen production rate was predicted to be optimal when the VS concentration ranged from 10 to 12 g/l at all the mixing ratios of molasses wastewater and sewage sludge. A hydrogen yield of over 50 ml $H_2/gVS_{removed}$ was obtained from mixed waste of 10% sewage sludge and 10 g/l VS (about 10-fold dilution ratio). The optimal chemical oxygen demand/total nitrogen ratio for co-digesting molasses wastewater and sewage sludge was between 250 and 300 with a hydrogen yield above 20 ml $H_2/gVS_{removed}$.

Anomalous Variations in Atmospheric Carbon Monoxide Associated with the Tsunami

  • Retnamayi, Anjali;Ganapathy, Mohan Kumar;Santha, Sreekanth Thulaseedharan
    • Asian Journal of Atmospheric Environment
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    • v.5 no.1
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    • pp.47-55
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    • 2011
  • Variations in ambient atmospheric carbon monoxide(CO) observed at an inland mining site in the Indo-Gangetic plains, Jaduguda ($22^{\circ}38'N$, $86^{\circ}21'E$, 122m MSL, ~75 km away from the coast of the Bay of Bengal) during the Tsunami of 26 December 2004 were monitored. CO mixing ratio over this site was measured using a non-dispersive infrared analyzer (Monitor Europe Model 9830 B). Back trajectory analysis data obtained using NOAA Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) Model was also used for this study. Variations in CO mixing ratio at a coastal site, Thiruvananthapuram ($8^{\circ}29'N$, $76^{\circ}57'E$, located ~2 km from the Arabian Sea coast) have also been investigated using CO data retrieved from the Measurement Of Pollution In The Troposphere (MOPITT) instrument. Ground-based measurements indicated abnormal variations in CO mixing ratio at Jaduguda from 25 December 2004 evening (previous day of the Tsunami). MOPITT CO data showed an enhancement in CO mixing ratio over Thiruvananthapuram on the Tsunami day. Back trajectory analyses over Thiruvananthapuram and Jaduguda for a period of 10 days from $21^{st}$ to $30^{th}$ December 2004 depicted that there were unusual vertical movements of air from high altitudes from 25 December 2004 evening. CO as well as the back trajectory analyses data showed that the variations in the wind regimes and consequently wind driven transport are the most probable reasons for the enhancement in CO observed at Jaduguda and Thiruvananthapuram during the Tsunami.

Direct Stacking of Non-metallic Planar Porphyrin to DNA

  • Lee, Min-Ju;Jin, Biao;Lee, Hyun-Mee;Jung, Maeng-Joon;Kim, Seog K.;Kim, Jong-Moon
    • Bulletin of the Korean Chemical Society
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    • v.29 no.8
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    • pp.1533-1538
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    • 2008
  • Porphyrins generally bind DNA in two different ways with respect to the mixing ratio; monomeric binding at a low mixing ratio and outside stacking at a high mixing ratio. In the present study, CTDNA binding property of a planar structured porphyrin, 5,10,15,20-tetrakis(N-methyl-4-pyridin-4-yl-phenyl)porphyrin (referred to as B-TMPyP) was investigated using absorption, CD, LD, and $LD^r$ spectroscopies. B-TMPyP produced a bisignate CD band, even at the lowest mixing ratio, indicating that B-TMPyP may not have a monomeric binding mode. From the observations of the spectral changes to the absorption, CD, and LD spectra in mixing ratio dependent titrations, B-TMPyP seems to have a quite different stacking type compared to that for the binding of $H_2$TMPyP. Moreover, B-TMPyP produced a CD band of opposite shape in the Soret band region. A qualitative explanation for the observed optical differences is also given.

Analysis of Strength Characteristic for Bottom Ash Mixtures as Mixing Ratio and Curing Methods (Bottom Ash와 혼합재료의 혼합비 및 양생방법에 따른 강도특성 분석)

  • Choi, Woo-Seok;Son, Young-Hwan;Park, Jae-Sung;Noh, Soo-Kack;Bong, Tae-Ho
    • Journal of The Korean Society of Agricultural Engineers
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    • v.55 no.3
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    • pp.129-140
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    • 2013
  • Bottom Ash is industrial by-product from a thermoelectric power plant. An immense quantities of bottom ash have increased each year, but most of them is reclaimed in ash landfill. In this study, in order to raise recycling rate of Bottom Ash, it is suggested to cure Bottom Ash (BA) mixtures mixed with cement, lime, Fly Ash (FA), and oyster shell (OS). Mixtures of 5~20 % mixing ratio had been cured for 1, 3, 7, 14, and 28 days using sealed curing and air-dry curing method. Unconfined compressive strength test was conducted to determine strength and deformation modulus ($E_{50}$) change for mixtures as mixing ratio and curing day, water contents of mixtures were measured after test. As a result, strength and $E_{50}$ were increased as mixing ratio and curing days, but values and tendencies of them appeared in different as kind of mixture, mixing ratio, curing method, and curing days. The results showed the addition of cement, lime, Fly Ash, and oyster soil in Bottom Ash could improved strength and $E_{50}$ and enlarge its field of being used.

Properties of Eco-friendly Artificial Stone according to the mixing ratio of Geopolymer-based recycled Aggregate (지오폴리머 기반 순환골재 혼입율에 따른 친환경성 인조석재의 특성)

  • Kyung, Seok-Hyun;Choi, Byung-Cheol;Kang, Yeon-Woo;Lee, Sang-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • pp.126-127
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    • 2020
  • Recently, as interest in environmental issues increases, minimizing carbon dioxide generated during cement manufacturing is a problem to be solved. In order to solve such a problem, it is required to use an industrial by-product of recycled aggregate, blast furnace slag, and circulating fluidized bed boiler fly ash to replace it on the basis of geopolymer(=cementless). This study examines the characteristics of eco-friendly artificial stone according to the mixing ratio of geopolymer-based recycled aggregate. As a result of the experiment, when the addition rate of the alkali stimulant was 15% and the mixing ratio of the circulating aggregate was 70%, the flexural strength and compressive strength were the highest. Density and water absorption decreased as density of circulating aggregates increased and water absorption increased. However, when the mixing ratio of the circulating aggregate exceeded 70%, the flexural strength and compressive strength decreased. Therefore, in order to obtain strengths meeting the KS standards, the mixing ratio of recycled aggregate was set to 70%, and artificial stone was manufactured using industrial by-products.

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Effect of agricultural and spent mushroom substrate on the mycelial growth of Trametes versicolor (농산부산물과 버섯 수확 후 배지가 구름버섯의 균사생장에 미치는 영향)

  • Chang, Hyun-You;Moon, Bu-Gyeong;Seo, Geum-Hui;Lee, Yong kuk
    • Journal of Mushroom
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    • v.15 no.1
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    • pp.21-24
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    • 2017
  • In this study, the effect of different substrates of agricultural by-products on the mycelial growth rate and density of Trametes versicolor (Turkeytail mushroom) was analyzed. We found that pepper stem and rice bran with a mixing ratio of 9:1(v/v) produced the best mycelial growth of 101 mm in 10 days, while a mixing ratio of 8:2 resulted in mycelial growth of 83 mm in 10 days. The control group treated with a 9:1 mixing ratio of oak sawdust and rice bran (v/v) produced mycelial growth of 74 mm in 10 days. The following results are in the order of beanstalk, sesame stem, and perilla stem. After the harvest of the mushrooms, the mycelial growth rate and the density of T. versicolor in each substrate were as follows the group with waste substrate of Pleurotus eryngii and rice bran with a mixing ratio of 9:1(v/v) produced the best result of 76 mm in days, while a mixing ratio of 8:2 produced of 61 mm in 10 days. The control group with a 9:1 ratio of oak sawdust and rice bran produced mycelia of 74 mm in 10 days, while a mixing ratio of 8:2 resulted in mycelia of 59 mm in10 days.

Study on mixing characteristics of T-type micro channel (미소 T 채널의 혼합 특성에 관한 연구)

  • Lee, Sang-Hyun;Ahn, Cheol-O;Seo, In-Soo;Lee, Sang-Hwan
    • Proceedings of the KSME Conference
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    • pp.2495-2500
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    • 2008
  • We simulated the mixing characteristics in micro T-channel using Lattice Boltzmann Method. We studied the relation a mixing length and pressure-drop due to inlet and outlet ration in Reynolds number 0.5, Peclet number 500 and Schmidt 1000. The ratio of a down-inlet to up-inlet was $0.5{\sim}1.5$ times, up-inlet to outlet was $1{\sim}3$ times and outlet length was 250 times to up-inlet. The mixing length decrease linearly as outlet ratio decreased, and pressure-drip increase non-linearly. Initial stage of micro channel mixture was fast by down-inlet ratio, however, the mixing length is not influence.

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Shape Optimization of A Micromixer with Herringbone Grooves Using Kriging Model (헤링본 미세혼합기의 크리깅 모델을 사용한 최적형상설계)

  • Ansari, Mubashshir Ahmad;Kim, Kwang-Yong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.8
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    • pp.711-717
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    • 2007
  • Shape optimization of a staggered herringbone groove micromixer using three-dimensional Navier-Stokes analysis has been carried using Kriging model. The analysis of the degree of mixing is performed by the calculation of spatial data statistics. The calculation of the variance of the mass fraction at various nodes on a plane in the channel is used to quantify mixing. A numerical optimization technique with Kriging model is applied to optimize the shape of the grooves on a single wall of the channel. Three design variables, namely, the ratio of groove width to groove pitch, the ratio of the groove depth to channel height ratio and the angle of the groove, are selected for optimization. A mixing index is used as the objective function. The results of the optimization show that the mixing is very sensitive to the shape of the groove which can be used in controlling mixing in microdevices.

Change of Paper's Physical and Fracture Mechanical Properties Depending on Fibers Properties (섬유 특성에 따른 종이의 물리적, 파괴 역학적 특성 변화)

  • 이진호;박종문
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.35 no.3
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    • pp.37-42
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    • 2003
  • Physical properties of paper can be explained in terms of the changes in fiber's morphological properties. As the paper machine speed increases, the basis weight decreases and the mixing ratio of inferior recycled fibers increases, paper break becomes important than ever before. One of the objectives of this study is to analyze paper's physical, mechanical and fracture mechanical properties depending on softwood(SW) and hardwood(HW) mixing ratios and recycling. Fibers were refined by Valley beater to 450 mL CSF. Handsheets of 30 g/$\textrm{m}^2$ were prepared at different mixing ratios. Fracture toughness was measured as the amount of energy applied to cracked sample before total failure. Fracture toughness showed different trend to other strength properties. At the mixing ratio of SW 80: HW 20, papers showed the maximum fracture toughness. At this mixing ratio, flexible softwood fibers were mostly broken and stiff hardwood fibers were mostly pulled out.

Electro-Optical Characteristics of External Electrode Fluorescent Lamp depending on Gas pressure and mixing ratio

  • Kim, Hyung-Dong;Jeon, Hyun-Woo;Lee, Chang-Ho;Yoon, Jung-Hyun;Kim, Jae-Bum;Lim, Jong-Ho;Shin, Jong-Keun;Chung, In-Jae
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.792-794
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    • 2008
  • We investigated influence of gas pressure and mixing ratio on the electro-optical properties of External Electrode Fluorescent Lamp (EEFL). The experimental results indicated that luminance and efficiency became the maximum at lower gas pressure and Ar mixing ratio.

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