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Evaluation of Solidified Fuel Value of Dairy Cattle Manure Digested by Semi-Dry Anaerobic Digestion Method (젖소분뇨 반 건식 혐기소화 잔재물의 고체연료화 가능성 평가)

  • Jeong, Kwang-Hwa;Kim, Jung Kon;Lee, Dong-jun;Cho, Won-Mo;Ravindran, B.;Kwag, Jung-Hoon
    • Journal of the Korea Organic Resources Recycling Association
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    • v.24 no.4
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    • pp.95-103
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    • 2016
  • The objective of this study was to investigate feasibility of semi-dry anaerobic digestion using dairy cattle manure and to evaluate solidified fuel value of semi-dry anaerobic digestate. To evaluate semi-dry anaerobic digestion using dairy cattle manure, 950 mL bottle type anaerobic reactor was set in the constant temperature room maintained at $35^{\circ}C$. To produce anaerobic digestate for making solidified fuel, acrylic cylindrical anaerobic digester(1,000 mm width ${\times}$ 450 mm height) was set in the constant room temperature to carry out batch test of semi-dry anaerobic digestion using same dairy cattle manure. Moisture content of dairy cattle manure and inoculum solution for anaerobic digestion were 80.64% and 96.83%, respectively. The dairy cattle manure and the inoculum solution was mixed by 1:1 ratio(v/v) for anaerobic digestion. Water content and VS/TS(Volatile Solids/Total Solids) of mixture of substrate and inoculum were 89.74% and 83.35%, respectively. In case of non-inoculated anaerobic digester, the biogas was not produced. By the semi-dry anaerobic digestion, the calorific value of the digestate was reduced by 20% compare to fresh dairy cattle manure. In other hand, ash content increased from 15% to 18.4%. The contents of Cr, Pb, Cd and S of pellet produced from anaerobically digested dairy cattle manure were not against the standard regulation for livestock manure solidified fuel. Therefore, it can be used as fuel that anaerobic digestate produced after semi-dry anaerobic digestion using dairy cattle manure.

Optimization of PS-7 Production Process by Azotobacter indicus var. myxogenes L3 Using the Control of Carbon Source Composition (탄소원 조성 조절을 이용한 Azotobacter indicus var. myxogenes L3로부터 PS-7 생산 최적화)

  • Ra, Chae-Hun;Kim, Ki-Myong;Hoe, Pil-Woo;Lee, Sung-Jae;Kim, Sung-Koo
    • Microbiology and Biotechnology Letters
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    • v.36 no.1
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    • pp.61-66
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    • 2008
  • The proteins in whey are separated and used as food additives. The remains (mainly lactose) are spray-dried to produce sweet whey powder, which is widely used as an additive for animal feed. Sweet whey powder is also used as a carbon source for the production of valuable products such as polysaccharides. Glucose, fructose, galactose, and sucrose as asupplemental carbon source were evaluated for the production of PS-7 from Azotobacter indicus var. myxogenes L3 grown on whey based MSM media. Productions of PS-7 with 2% (w/v) fructose and sucrose were 2.05 and 2.31g/L, respectively. The highest production of PS-7 was 2.82g/L when 2% (w/v) glucose was used as the carbon source. Galactose showed low production of PS-7 among the carbon sources tested. The effects of various carbon sources addition to whey based MSM medium showed that glucose could be the best candidate for the enhancement of PS-7 production using whey based MSM medium. To evaluate the effect of glucose addition to whey based media on PS-7 production, fermentations with whey and glucose mixture (whey 1, 2, 3%; whey 1% + glucose 1%, whey 1% + glucose 2% and glucose 2%, w/v) were carried out. Significant enhancement of PS-7 production with addition of 1% (w/v) and 2% (w/v) glucose in 1% (w/v) whey media was observed. The PS-7 concentration of 2% glucose added whey lactose based medium was higher than that of 1% glucose addition, however, the product yield $Y_{p/s}$ was higher in 1% glucose added whey lactose based MSM medium. Therefore, the optimal condition for the PS-7 production from the Azotobacter indicus var.myxogenes L3, was 1% glucose addition to 1% whey lactose MSM medium.

Effects of Salinity Level and Irrigation Rate on Kentucky Bluegrass (Poa pratensis L.) Growth and Salt Accumulation in Sand Growing Media Established Over the Reclaimed Saline Soil (염해지 토양을 기반으로 조성된 모래 지반구조에서 관수용수의 량 및 염농도에 따른 토양내 염류 집적과 켄터키 블루그래스의 생육에 미치는 영향)

  • Rahayu, Rahayu;Yang, Geun-Mo;Choi, Joon-Soo
    • Asian Journal of Turfgrass Science
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    • v.25 no.1
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    • pp.79-88
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    • 2011
  • The purpose of this study was to obtain information on rates and salinity levels of irrigation for growth of Kentucky bluegrass by minimizing the hazard of salt accumulation in the sand based growing medium. Root zone profile consists of 20 cm sand based top soil, 20 cm of coarse sand as layer to interrupt capillary rise and 10 cm of reclaimed paddy soil as a base of the root zone profile. Topsoil was a mixture of dredged sand and peat with a ratio of 95%: 5% by volume. The columns were soaked into 5 cm depth saline water reservoir with salinity level of 3-5 $dSm^{-1}$. Salinity levels of irrigation water were 0, 2 and 3 $dSm^{-1}$. Irrigation rates were 3.8, 5.7 and 7.6 mm $day^{-1}$ which were equivalent to 70%, 100% and 130% of average ET (evapotranspiration) rate of Kentucky bluegrass, and irrigation interval was 3 days. Salt accumulation was due to irrigated water and moved up water from shallow water base. At the end of second year, the accumulation of salt in the rootzone showed ECc of3.86, 4.7 and 5.1 $dSm^{-1}$, and SAR of 19.2, 23.9 and 27.5 when the salinities were 0, 2 and 3 dS $m^{-1}$, respectively. Irrigation rates of 100% and 130% of ET rate with saline water did not decrease ECe and SAR in growing media. The growth of KEG was influenced by irrigation rate in the $1^{st}$ year, however, salinity level was more critical in the $2^{nd}$ year. Compared to non-saline water, saline water of 2 and 3 dS $m^{-1}$ resulted in decreased visual quality by 3.2% and 16.5%, by 6.4% and 39.3% in clipping weight, and by 5.5% and 5.0% in root mass, respectively.

The Study of Operating Conditions by Establishing Density Currents Generator for Improving of Water Quality on Lake Water - With Focus on DO and Water Temperature - (호소수의 수질개선을 위한 DCG 설치시 운전조건에 관한 연구 - DO와 수온을 중심으로 -)

  • Lee, Young-Shin;Han, Kyung-Hee;Kim, Young-Kyu;An, Hyung-Chul;Shin, Sung-Woo
    • Journal of Korean Society of Environmental Engineers
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    • v.36 no.4
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    • pp.286-294
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    • 2014
  • The purpose of this study is to investigate the effects of applying density current generator (hereafter referred to as DCG to large lakes on the operating conditions of DCG, de-stratification, water quality improvement and inhibition of algae occurrence. As a result of a survey conducted to derive the optimum operating parameters of DCG in a condition to minimize eco-toxicity, the following conclusions were obtained. During the survey period, a marked stratification appeared in September to October 2011 and May 2012. At this time, the average depth of water to form thermocline was found to be $5{\pm}2$ m, so the location of discharge port for the operation of DCG was determined to be about 5 m below from the surface. To minimize the adverse effects of benthos and obtain the effect of water mixture at the time of water circulation, the mixing ratio of surface water and deep water was designed to be 3:1 by means of ecotoxicological assessment on the DCG operating characteristics. To select the appropriate operating hours for DCG, DCG was operated by 12 hr, 24 hr, 36 hr and 48 hr. As its result, the formation of thermocline did not occur during the operation of 36 hr. Also, It was effected that start reoperating from 3rd day after stop 2days under the condition of operated during 36 hr with calculated power consumption. Under the above conditions, the results of DO and water temperature analysis during the operation of DCG showed that the stratification, which was distinct previously, appeared to be weak, and relatively lower levels than those before operation were found as a result of water quality analysis on COD and chlorophyll-a, which leads to the conclusion that the water body is maintained at a stable condition due to the circulation of water by the occurrence of density current resulting from the operation of DCG.

Changes of Microbial Activity and Physicochemical Environment during Composting of Papermill Sludge in a Pilot Plant (제지슬럿지의 퇴비화 과정 중 미생물활성 및 이화학적 환경변화)

  • Chung, Young-Ryun;Chung, Man-Hoon;Han, Shin-Ho;Oh, Say-Kyun
    • Journal of the Korea Organic Resources Recycling Association
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    • v.3 no.2
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    • pp.79-89
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    • 1995
  • Changes of microbial activity and physicochemical environment during composting of papermill sludge(PMS) in the pilot plant equipped with an agitated bed reactor were monitored for establishing the efficient composting system. Microbial activity determined as the evolution of $CO_2$ increased for the first 10 days after introduction of PMS to the reactor and decreased thereafter. Population changes of microorganisms in the reactor-PMS were not typical as in windrow system. The ratio of thermophilic bacteria to mesophilic bacteria, however, increased slowly even 23 days after introduction. Temperature of PMS increased rapidly from the first day and reached $62^{\circ}C$ at 7 days after introduction and decreased slowly thereafter. The acidity of PMS was pH 6.8 initially, increased to pH 8.0 after 7 days and decreased to pH 7.4 after 23 days. Redox potential(Eh) of PMS was -320mV at the beginning of composting, but it was increased with time to reach -15mV after 23 days composting. However, Eh of PMS pre-sterilized before measurement was average 50mV, regardless of composting periods indicating the major role of microorganisms during composting process. Water content of PMS was 67% initially and decreased to about 50% after 23 days composting in the reactor. Less than 13 days-old compost inhibited growth of radish in the container mixture with bed soil. Based on statistical analysis of microbial and physicochemical parameters of PMS during composting, an equation was developed for determining compost maturity. A number of experiments using various organic wastes are required before application of the formular to the practical use.

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Growth and optical conductivity properties for MnAl2S4 single crystal thin film by hot wall epitaxy method (Hot Wall Epitaxy(HWE)법에 의한 MnAl2S4 단결정 박막 성장과 광전도 특성)

  • You, Sangha;Lee, Kijeong;Hong, Kwangjoon;Moon, Jongdae
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.24 no.6
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    • pp.229-236
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    • 2014
  • A stoichiometric mixture of evaporating materials for $MnAl_2S_4$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $MnAl_2S_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperatures were $630^{\circ}C$ and $410^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The temperature dependence of the energy band gap of the $MnAl_2S_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=3.7920eV-5.2729{\times}10^{-4}eV/K)T^2/(T+786 K)$. In order to explore the applicability as a photoconductive cell, we measured the sensitivity (${\gamma}$), the ratio of photocurrent to dark current (pc/dc), maximum allowable power dissipation (MAPD) and response time. The results indicated that the photoconductive characteristic were the best for the samples annealed in S vapour compare with in Mn, Al, air and vacuum vapour. Then we obtained the sensitivity of 0.93, the value of pc/dc of $1.10{\times}10^7$, the MAPD of 316 mW, and the rise and decay time of 14.8 ms and 12.1 ms, respectively.

Rheological and Debinding Properties of Al2O3/Paraffin Wax/High Density Polyethylen System Mixture by Injection Molding (사출성형에 의한 Al2O3/Paraffin Wax/High Density Polyethylen계 혼합물의 유동성 및 탈지 특성)

  • 김승겸;신대용;한상목;강위수
    • Journal of the Korean Ceramic Society
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    • v.41 no.5
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    • pp.395-400
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    • 2004
  • The effects of compositions of binders on the rheological properties of mixtures and the preparation conditions on the formation of defects and the debinding characteristics of compacts for the injection molding of ceramic powders (65 wt% aluminaㆍ35 wt% feldspar) were studied. Ceramic powders were coated with 2 wt% of stearic acid and then mixed with 15, 20, and 25 wt% of Paraffin Wax (PW) and High Density Polyethylene (HDPE) as binders at $160^{\circ}C$ for 2 h. Rheological properties were investigated by using capillary rheometer. Apparent viscosities of mixtures were 80∼300 Paㆍs at 1,000$s^{-1}$ of a shear rate, it was good for the injection molding and depending on the compositions of binders. Short shot was formed at 15H5P5 (the ratio of HDPE : PW=5 : 5 in 15 wt% of binders) compacts without injection pressures and any noticeable defects were not formed at 45 kgf/$cm^{2}$ in 20H5P5 compacts. PW and HDPE were removed by the solvent extraction and thermal debinding method. Thermal debinding of HDPE at $450^{\circ}C$ for 5 h, which followed the extraction of PW was using n-heptane solvent at $70^{\circ}C$ for 5 h. Continuous pores in compacts, which facilitate the removal of HDPE by the thermal debinding, were found to form in the compacts when PW was removed by the solvent extraction. The optimum composition of binder at which binder was removed by thermal debinding without defects while maintaining the compact strength was 20H5P5. Bulk density, porosity and 3-point bending strength of 20H5P5 compact sintered at 1,30$0^{\circ}C$ for 5 h were 2.8, < 3%, and 2,400 kgf/$cm^{2}$, respectively, and can be used as a structural materials.

Development of Extruded Pellet for Growth of Flounder (Paralichthys olivaceus) in Commercial Scale Feeding Trials (넙치 육성용 배합사료 개발을 위한 현장 사육 실험)

  • Seo, Joo-Young;Choi, Jin;Lee, Jong-Ha;Lee, Sang-Min
    • Journal of Aquaculture
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    • v.20 no.2
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    • pp.114-120
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    • 2007
  • Two feeding experiments were conducted to evaluate the effects of the experimental extruded pellet (EP), commercial EP and raw fish-based moist pellet (MP) on growth of growing flounder (Paralichthys olivaceus). In experiment 1, two replicate groups of the fish (average body weight of $115{\pm}3.2\;g$) were fed one of five experimental diets (EP1-EP5) and MP in circular concrete tanks (4.6 m $\phi$, 0.6 m depth) for 78 days. In experiment 2, in order to evaluate EP in the commercial scale ($8\;m\;{\times}\;8\;m$), flounder (average body weight of $137{\pm}11.4\;g$) were fed one of five EPs (EP1-EP5) used in experiment 1, commercial EP (EP6) and two MEPs (MEP4 and MEP6) as moist pellet types which were made from EP4 and EP6, respectively, by being sprayed with a mixture of water and additives for 80 days. In experiment 1, weight gain of fish fed the all EPs was not significantly different from that of MP. Feed efficiency of fish fed the EP4 was highest, and protein efficiency ratio of fish fed the EP4 and EP5 was significantly higher than that of fish fed the MP (P<0.05). Significant differences were observed in the contents of moisture and crude lipid in the muscle, and moisture in the liver of fish (P<0.05). In experiment 2, weight gain of fish fed the EP4 and MEP4 were highest and feed efficiency showed high tendency in EP4, MEP4 and MEP6. Fish fed the MEP6 showed higher weight gain and feed efficiency compared to those of fish fed the EP6, but there was no difference in those of fish fed EP4 and MEP4. Based on the results of this study, dietary formulations used in EPs could be most recommendable applied in the practical extruded pellet feeds for flounder grown from 114 g to 350 g.

Characteristics of Obstructive Sleep Apnea Syndrome Patients Proven with Nocturnal Polysomnography as Correlates of Age and Gender (야간 수면다원 기록으로 확진된 폐쇄성 수면무호흡증 환자의 특성: 연령과 성별에 따른 차이)

  • Lee, Ju-Young;Kim, Seog-Ju;Lee, Jung-Ho;Jeong, Do-Un
    • Sleep Medicine and Psychophysiology
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    • v.16 no.2
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    • pp.65-73
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    • 2009
  • Objectives: The purpose of this study was to assess the clinical and polysomnographic characteristics of Korean patients with obstructive sleep apnea syndrome (OSAS), especially in relation to differences due to age and gender. Methods: All subjects were consecutive patients who were proven to have OSAS with nocturnal polysomnography. They were interviewed with a structured interview format including sociodemographic information, past medical history, medication, and sleep-related history. Simultaneously, they were also given Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS) to answer in order to check subjective sleep quality and subjective sleepiness. Results: Mean age of the 308 subjects was $49.5{\pm}$13.3 years, with 77.6% of the subjects being males and 22.4% of the subjects being females. The aging effects on the sleep architecture in Korean OSAS corresponded with normal aging, but with the effect of OSAS itself superimposed, the extent of aging effects was more marked than that of normal aging. The severity of Korean patients of OSAS was not correlated with age. When divided into age subgroups, significant correlation was found between RDI and BMI in patients of each subgroup of those in the 4th to 7th decades. The oldest subgroup (>70 years) described their subjective sleep quality as poorer than any other age subgroups, despite of less subjective drowsiness. The severity of OSAS and the change of sleep architecture of male subjects turned out to be severer than those of female ones. The female/male ratio of the subjects tended to increase with aging. Conclusions: The aging effect on the sleep architecture in Korean OSAS seems to be a mixture of the changes by normal aging and sleep disorder per se. The severity of OSAS was not correlated with age, but highly correlated with BMI. The severity of OSAS and the change of sleep architecture of male patients were severer than those of female ones.

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Anti-Obesity Effect of Red Garlic Composites in Rats Fed a High Fat-Cholesterol Diet (고지방-콜레스테롤 식이성 흰쥐에서 홍마늘 복합물의 항비만 효과)

  • Lee, Soo-Jung;Hwang, Cho-Rong;Kang, Jae-Ran;Shin, Jung-Hye;Kang, Min-Jung;Sung, Nak-Ju
    • Journal of Life Science
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    • v.22 no.5
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    • pp.671-680
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    • 2012
  • Three kinds of dietary composites-R+T, R+F, and R+TF-were combined in green tea (T), dietary fiber (F), and green tea dietary fiber mixture (TF) to red garlic extract (RG), respectively. The effects of their diets on anti-obesity were investigated $in$ $vitro$ and $in$ $vitro$ in obese rats induced high fat-cholesterol. In $in$ $vivo$ rats, the total phenolic content of the R+T and R+TF was 1.9~2.0 times higher, and their total cholesterol adsorption was 9.5~11.5 times higher than that of RG. $In$ $vivo$, male Sprague-Dawley rats were divided into 6 groups (Normal, HFC, HRG, HR+T, HR+F and HR+TF). Afterwards, the diets of the HRG, HR+T, HR+F, and HR+TF groups were supplemented with 1% of RG and its dietary composites (R+T, R+F, and R+TF) for 4 weeks, respectively. The final body weight of the HRG, HR+T, HR+F, and HR+TF groups decreased significantly compared to the group fed high fat-cholesterol (HFC), but the food efficiency ratio was not significantly different from the HFC group. The liver weight of the HFC group doubled compared to the normal group, whereas that of HR+T and HR+TF groups decreased significantly. The weight of visceral and epididymal fat decreased significantly in the groups fed the composites compared to the HFC group. The obesity index of HR+TF group decreased significantly only when compared to the HFC group. The serum lipid profile such as total lipids, cholesterol, triglyceride, LDL- and VLDL-cholesterol, as well as the atherogenic index and cardiac risk factors decreased drastically in all experimental groups compared to the HFC group, and the levels of HR+T, HR+F and HR+TF groups were a similar trend. GPT activity was not significantly different among the groups fed the composites, and it decreased significantly in the HRG group. The content of the lipid peroxide level decreased significantly in the HRG group and in the groups fed the composites, compared to the HFC group. Serum antioxidant activity was the highest in the HR+T group. We suggest that the hypolipidemic and anti-obesity effect of the RG composites, achieved by mixing green tea extract and/or dietary fiber, was due to their total phenolic content and total cholesterol adsorption effect.