• Title/Summary/Keyword: gas production

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Experimental Study on Autothermal Reformation of Methanol with Various Oxygen to Methanol Ratios for Fuel Cell Applications (연료전지용 메탄올 자열 개질기의 산소-메탄올 비율에 따른 성능 실험)

  • Hwang, Ha-Na;Shin, Gi-Soo;Jang, Sang-Hoon;Choi, Kap-Seung;Kim, Hyung-Man
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.35 no.4
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    • pp.391-397
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    • 2011
  • The use of Hydrogen as a fuel is receiving considerable attention and as a result, research on novel methods of hydrogen production is necessary so that the hydrogen demands in the future can be satisfied. This study presents experimental data on methanol Autothermal Reformation that quantifies the relationship between the oxygen-to-methanol ratio ($O_2/CH_3OH$) and reformer efficiency. For each catalyst configuration, the $O_2/CH_3OH$ was varied from 0.1 to 0.4, with an increment of 0.05, to investigate the effects of $O_2/CH_3OH$ on the reactor performance, including temperature profile, conversion, and efficiency. $O_2/CH_3OH$ was increased from 0.15 to 0.20, and the catalyst bed temperature increased by $235^{\circ}C$ to approximately $550^{\circ}C$. The catalyst bed temperature increased with increasing $O_2/CH_3OH$ as the reaction shifted from endothermic to exothermic reaction and as a result, excess heat, which raised the reactor temperature, was generated. The reactor performance was shown to be highly dependent on $O_2/CH_3OH$. The optimum $O_2/CH_3OH$ = 0.30 found in the experimental tests is 30% higher than the theoretical optimum of 0.23. This is attributed to a combination of factors such as the concentrations of the $O_2$ and $CH_3OH$ gas, reaction rate, catalyst effects, heat loss from the reactor, and the difference between the actual amounts of reaction products formed and the theoretical amounts of the reaction products.

Effects of spent mushroom (Flammulina velutipes) substrates on in vitro ruminal fermentation characteristics and digestibility of whole crop sorghum silage (팽이버섯 수확후배지 첨가가 수수 사일리지의 in vitro 반추위 발효특성 및 소화율에 미치는 영향)

  • Moon, Yea Hwang;Chang, Sun Sik;Kim, Eun Tae;Cho, Woong Gi;Lee, Shin Ja;Lee, Sung Sil;Cho, Soo Jeong
    • Journal of Mushroom
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    • v.13 no.3
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    • pp.163-169
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    • 2015
  • The in vitro experiment was conducted to ensure the supplemental level of spent Flammulina velutipes mushroom substrates (SMS) as an energy source in manufacturing of whole crop sorghum silage. Sorghum harvested at heading stage was ensiled with spent mushroom substrates of 20% (S-20), 40% (S-40) and 60% (S-60) as fresh matter basis for 6 week. The experiment was conducted by 3, 6, 9, 12, 24, 48 hrs of incubation time with 3 replications. The silages were evaluated fermentation characteristics and dry matter digestibility (DMD) in vitro. The pH of in vitro solution was inclined to decrease with elapsing the incubation time, and that of the S-20 was significantly (P<0.05) lower than the other treatment at 48 hr of incubation. Gas production was greater (P<0.05) in the S-20 than the other treatments at 6 and 12 hrs of incubation. The microbial growth in vitro was inclined to decrease following 24 hr of incubation, and thereafter sustained the similar levels. In vitro dry matter digestibility (IVDMD) was lowered by increasing the supplemental level of spent mushroom substrate, and was a low level in the S-60 throughout whole incubation time. Although the IVDMD for S-40 was steadily increased from 9 hr of incubation and reached to similar level with the S-20 at 48 hour of incubation, however SMS for whole crop sorghum silage fermentation might as well add about 20 to 30% in fresh matter basis when considering DMD.

Impacts of R&D and Smallness of Scale on the Total Factor Productivity by Industry (R&D와 규모의 영세성이 산업별 총요소생산성에 미치는 영향)

  • Kim, Jung-Hwan;Lee, Dong-Ki;Lee, Bu-Hyung;Joo, Won
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.2 no.4
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    • pp.71-102
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    • 2007
  • There were many comprehensive analyses conducted within the existing research activities wherein factors affecting technology progress including investment in R&D vis-${\Box}$-vis their influences act as the determinants of TFP. Note, however, that there were few comprehensive analysis in the industrial research performed regarding the impact of the economy of scale as it affects TFP; most of these research studies dealt with the analysis of the non -parametric Malmquist productivity index or used the stochastic frontier production function models. No comprehensive analysis on the impacts of individual independent variables affecting TFP was performed. Therefore, this study obtained the TFP increase rate of each industry by analyzing the factors of the existing growth accounting equation and comprehensively analyzed the TFP determinants by constructing a comprehensive analysis model considering the investment in R&D and economy of scale (smallness by industry) as the influencers of TFP by industry. First, for the TFP increase rate of the 15 industries as a whole, the annual average increase rate for 1993${\sim}$ 1997 was approximately 3.8% only; during 1999${\sim}$ 2000 following the foreign exchange crisis, however, the annual increase rate rose to approximately 7.8%. By industry, the annual average increase rate of TFP between 1993 and 2000 stood at 11.6%, the highest in the electrical and electronic equipment manufacturing business and IT manufacturing sector. In contrast, a -0.4% increase rate was recorded in the furniture and other product manufacturing sectors. In the case of the service industry, the TFP increase rate was 7.3% in the transportation, warehousing, and communication sectors. This is much higher than the 2.9% posted in the electricity, water, and gas sectors and -3.7% recorded in the wholesale, food, and hotel businesses. The results of the comprehensive analysis conducted on the determinants of TFP showed that the correlations between R&D and TFP in general were positive (+) correlations whose significance has yet to be validated; in the model where the self-employed and unpaid family workers were used as proxy variables indicating the smallness of industry out of the total number of workers, however, significant negative (-) correlations were noted. On the other hand, the estimation factors of variables surrogating the smallness of scale in each industry showed that a consistently high "smallness of scale" in an industry means a decrease in the increase rate of TFP in the same industry.

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Early Response of Cardiopulmonary Exercise Test(CPET) in Patients with Locally Advanced Non-Small Cell Lung Cancer Treated with Radiation (방사선 치료 후 폐암환자의 운동부하 심.폐 기능의 초기변화)

  • Shin, Kyeong-Cheol;Lee, Deok-Hee;Lee, Kwan-Ho
    • Tuberculosis and Respiratory Diseases
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    • v.49 no.4
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    • pp.466-473
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    • 2000
  • Background : Patients with locally advanced non-small cell lung cancer are often treated with radiation alone or in combination with chemotherapy. Both modalities have a potentially damaging effect on pulmonary function. In order to examine changes in the cardiopulmonary exercise function of patients with locally advanced non-small cell lung cancer before and after conventional radiotherapy, we conducted a prospective study involving patients with such cancer, that had received radiation therapy. Method : Resting pulmonary function test, thoracic radiographic finding and cardiopulmonary exercise test(CPET) were assessed prior to and 4 weeks following radiation therapy in 11 male patients with locally advanced non-small cell lung cancer. Patient with endobronchial mass were excluded. Results : The forces vital capacity (FVC), forced expiratory volume in 1 second ($FEV_1$ and maximal voluntary ventilation (MVV) did not decreased between before and 4 weeks after radiation but the diffusing capacity (DLCO) had decreased by 11% 4 weeks after radiation, which was not statistically significant. No changes in maximal oxygen consumption ($VO_2$max), carbon dioxide production ($VCO_2$), exercise time and work load were attributed to radiation therapy. Follow up cardiopulmonary exercise testing revealed unchanged cardiovascular function, ventilatory function and gas exchange. No difference in cardiopulmonary exercise test performance was observed between pre- and post-radiation. Conclusion : Cardiopulmonary exercise function did not decrease within the short-term after the radiation of patients with locally advanced non-small cell lung cancer.

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Effect of the Salt Concentration in Seafood Processing Wastewater on the Anaerobic Ultimate Biodegradability and Multiple Decay Rate of Organic Matter (해산물 가공폐수내 염분농도가 혐기성 최종생분해도와 유기물 다중분해속도에 미치는 영향)

  • Choi, Yong-Bum;Kwon, Jae-Hyouk;Rim, Jay-Myung
    • Journal of Korean Society of Environmental Engineers
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    • v.32 no.11
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    • pp.1038-1045
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    • 2010
  • In this study, the anaerobic ultimate biodegradability and multiple decay rate of organic matter were evaluated according to various salt concentrations in seafood processing wastewater. The evaluation was also performed with various types of anaerobic bacteria and S/I (substrate/inoculum) ratios. After the S/I ratio was fixed at 0.9, the ultimate biodegradability values of the anaerobic digested sludge and granular sludge were became 72.0% and 92.0%, respectively. The multiple decay rate coefficients ($k_1$) coefficients of the anaerobic digested sludge and granular sludge were $0.0478{\sim}0.1252\;day^{-1}$ and $0.0667{\sim}0.1709\;day^{-1}$, respectively. The optimum S/I ratio of the seafood wastewater, which was determined based on the ultimate anaerobic biodegradability and gas production, was 0.9. The organic matter removal rate never became less than 85.0% under a 3,000 mg/L chloride concentration. The multiple decay rate coefficients ($k_1$) were $0.1603{\sim}0.1709\;day^{-1}$ under $3,000\;mgCl^-/L$, and $0.0492{\sim}0.0760\;day^{-1}$ in more than $6,000\;mgCl^-/L$. The multiple decay rate coefficients ($k_2$) were $0.0183{\sim}0.0348\;day^{-1}$ under $6,000\;mgCl^-/L$, and $0.0154\;day^{-1}$ at $9,000\;mgCl^-/L$. With increasing chloride concentrations, the reaction rate ($k_1$, $k_2$) and ratio of the rapidly degraded organic matter ($S_1$) decreased.

Evaluation of Odors and Odorous Compounds from Liquid Animal Manure Treated with Different Methods and Their Application to Soils (액상 가축분뇨의 처리 및 토양환원에 따른 악취 및 악취물질의 평가)

  • 고한종;최홍림;김기연;이용기;김치년
    • Journal of Animal Science and Technology
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    • v.48 no.3
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    • pp.453-466
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    • 2006
  • To comply with stricter regulations provoked by increasing odor nuisance, it is imperative to practice effective odor control for sustainable livestock production. This study was conducted to assess odor and odorous compounds emitted from liquid animal manure with different treatment methods such as Fresh Manure(without treatment, FM), Anaerobic Digestion(AD) and Thermophilic Aerobic Digestion(TAD) and their application to soil. Air samples were collected at the headspace of liquid manure, upland and paddy soil, and analyzed for odor intensity and offensiveness using an olfactometry; odor concentration index using odor analyser; nitrogen-containing compound such as ammonia(NH3) using fluorescence method; and sulfur containing compounds such as hydrogen sulfide(H2S), methyl mercaptan(MeSH), dimethyl sulfide(DMS) and dimethyl disulfide(DMDS) using gas chromatography-pulsed flame photometric detector, respectively. Odor intensity, offensiveness and concentration index from TAD liquid manure was statistically lower than those from FM and AD(p<0.01). Mean concentrations of H2S, MeSH, DMS, DMDS and NH3 were 65.93ppb, 18.55ppb, 5.26ppb, 0.33ppb and 10.57ppm for liquid manure with AD; and 5.15ppb, 0.97ppb, 0.80ppb, 0.56ppb and 1.34ppm for liquid manure with TAD, respectively. More than 60% of malodorous compounds related to nitrogen and sulfur were removed by heterotrophic microorganisms during TAD treatment. When liquid manure was applied onto upland and paddy soil, NH3 removal efficiencies ranged from 51 to 94% and 22 to 91% for AD and TAD liquid manure, respectively. The above results show that liquid manure with TAD is superior to AD and FM with respect to the odor reduction and odor problem caused by land applied liquid manure is directly related to the degree of odor generated by the manure treatment method.

Production of Poly-3-hydroxybutyrate from Xylose by Bacillus megaterium J-65 (Bacillus megaterium J-65에 의한 xylose로부터 poly-3-hydroxybutyrate 생산)

  • Jun, Hong-Ki;Jin, Young-Hi;Kim, Hae-Nam;Kim, Yun-Tae;Kim, Sam-Woong;Baik, Hyung-Suk
    • Journal of Life Science
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    • v.18 no.12
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    • pp.1625-1630
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    • 2008
  • A microorganism capable of producing high level of poly-3-hydoxybutyrate (PHB) from xylose was isolated from soil. The isolated strain J-65 was identified as Bacillus megaterium based on the morphological, biochemical and molecular biological characteristics. The optimum temperature and pH for the growth of B. megaterium J-65 were $37^{\circ}C$ and 8.0, respectively. The optimum medium composition for the cell growth was 2% xylose, 0.25% $(NH_4)_2SO_4$, 0.3% $Na_2HPO_4{\cdot}12H_2O$, and 0.1% $KH_2PO_4$. The optimum condition for PHB accumulation was same to the optimum condition for cell growth. Copolymer of ${\beta}$-hydroxybutyric and ${\beta}$-hydroxyvaleric acid was produced when propionic acid was added to shake flasks containing 20 g/l of xylose. Fermenter culture was carried out to produce the high concentration of PHB. In batch culture, cell mass was 9.82 g/l and PHB content was 35% of dry cell weight. PHB produced by B. megaterium J-65 was identified as homopolymer of 3-hydoxybutyric acid by GC and NMR.

Effects of Partial Replacement of Corn Grain and Soybean Meal with Agricultural By-Product Feeds on In Vitro Rumen Fermentation Characteristics and Optimum Levels of Mixing Ratio (농산부산물을 이용한 In Vitro 반추위발효 특성 및 적정 배합수준을 통한 옥수수 및 대두박 대체 효과)

  • Park, Joong-Kook;Lim, Dong-Hyun;Kim, Sang-Bum;Ki, Kwang-Seok;Lee, Hyun-June;Kwon, Eung-Gi;Cho, Won-Mo;Kim, Chang-Hyun
    • Journal of Animal Science and Technology
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    • v.53 no.5
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    • pp.441-450
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    • 2011
  • This study was conducted to determine the effects of partial replacement of corn grain and soybean meal with agricultural by-product feeds on in vitro rumen fermentation characteristics and optimum levels of mixing ratio. The agricultural by-products to examine the effectiveness of the partial replacement of concentrate were wheat bran, corn gluten feed, bakery waste, soybean curd, rice bran, green kernel rice, soybean hull, distillers' grain, and mushroom substrate. In the first experiment, in vitro ruminal fermentation characteristics of feedstuffs were evaluated at 0, 3, 6, 12, 24, and 48 hours after incubation. In the second experiment, fermentation characteristics were investigated with green kernel rice and soybean curd which replaced corn grain or soybean meal. Feed were formulated with 40% corn grain + 20% soybean meal (T1), 40% corn grain + 17.5% soybean meal + 2.5% soybean curd (T2), 25% corn grain + 20% soybean meal + 15% green kernel rice (T3), and 30% corn grain + 15% soybean meal + 6% green kernel rice + 9% soybean curd (T4), respectively, with forage source of 10% alfalfa hay, 20% timothy hay, and 10% corn silage as fed-basis. In 24 and 48 hour cultivations, T4 showed significantly lower pH compared to T1, whereas in 3 and 24 hour cultivations, T4 showed significantly higher DM degradation compared to T1. In addition, the gas production of T3 was also higher than T1 (p<0.05). Overall results of the present experiments indicated that green kernel rice and soybean curd as agricultural by-products have the possibility of partial replacements of corn grain and soybean meal.

Effect of Nitrogen Application Level and Regrowth Period on Composition of Fatty Acid in Tall fescue and Bermudagrass (질소시비 수준 및 재생기간이 톨페스큐와 버뮤다그라스의 지방산조성에 미치는 영향)

  • Park, Hyung-Soo;Hwang, Kyung-Jun;Park, Nam-Gun;Kim, Young-Jun;Jeong, Ha-Yeon;Jo, Nam-Chul;Ko, Moon-Suck
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.29 no.1
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    • pp.43-50
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    • 2009
  • Two experiments were conducted to evaluate the effects of nitrogen (N) application level and regrowth period on the fatty acid (FA) concentration and forage production of tall fescue (Festuca arundinacea Schr.) and bermudagrass (Cynodon dactylon (L.) Pers.). N was applied at 0, 50 and 100 kg/ha, and swards were cut after regrowth periods (15d, 30d and 45d). Concentrations of Individual FA were determined by gas chromatography. FA composition of tall fescue contains a high proportion ($87{\sim}88%$) of total FA contents as palmitic (C16:0), linoleic (C18:2) and linolenic acid (C18:3). The FA composition was not affected by N application, but a longer regrowth period significantly (p<0.05) decreased the composition of linolenic acid (C18:3) and increased those of linoleic acid (C18:2). The FA composition of bermudagrass was not affected by N application, but a longer regrowth period significantly (p<0.001) decreased the composition of linoleic (C18:2) and linolenic acid (C18:3). Linoleic and linolenic acfd of tall fescue were higher than those of bermudagrass. Dry matter (DM) yield of bermudagrass was significantly (P<0.05) affected by N application level and regrowth period. DM yield was higher at high N application and was higher at longer regrowth period. The crude protein concentration was higher at high N application and was low at longer regrowth period. Application of nitrogen fertilizer Increases dry matter (DM) yield and crude protein (CP) content of bermudagrass. These studies demonstrate opportunities to affect the FA concentration and composition of FA in forage through management strategies, which could affect milk FA composition.

Antioxidant Activity and Main Volatile Flavor Components of Mulberry Wine Fermented with Saccharomyces cerevisiae B-8 (토종발효미생물을 이용한 오디 발효주의 항산화 활성 및 향기성분 분석)

  • Chae, Kyu Seo;Jung, Ji Hye;Yoon, Hae Hoon;Son, Rak Ho
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.7
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    • pp.1017-1024
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    • 2014
  • This study was carried out to develop mulberry wines fermented with traditional microorganisms (Saccharomyces cerevisiae B-8). S. cerevisiae B-8 is a traditional fermentation microorganism isolated from domestically grown Rubus occidentalis. Each S. cerevisiae B-8 and Fermivin was inoculated into mulberry up to $1{\times}10^9$ CFU/kg, followed by incubation at $25^{\circ}C$ for 10 days. Mulberry fermented with S. cerevisiae B-8 (MBB) had a high alcohol content (16.47%), and the fermentation rate of MBB was faster than that of mulberry fermented with Fermivin (MBF). The total polyphenol and flavonoid contents of MBB were higher than those of MBF. DPPH radical scavenging activity of MBB was as high as that of MBF. ABTS radical scavenging activity of MBF was higher than those of MBB and mulberry juice (MBJ). In addition, reducing power of MBB was much higher than other samples. Flavor constituents of the two fermented wines were analyzed by gas chromatography and mass spectrometry. Twenty-three compounds from the sample were separated and identified as fifteen esters, six alcohols, an aldehyde, and an acetate. Particularly, tetradecanoic acid, ethyl ester of orris and violet flavor were ten times more abundant in MBB than in MBF. Several ester components were two times more abundant in MBB than in MBF. In conclusion, current findings indicate that MBB might have better antioxidant activities with flavor, which contributes to improved wine production with high quality and function.