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The Effects of Initial pH on VFAs Production of Mesophilic and Thermophilic Acidogenic Fermentation for Food Waste Recycling Wastewater (음폐수의 중온 및 고온 산발효에서 초기 pH가 VFAs 생성에 미치는 영향)

  • Byun, Im-Gyu
    • Journal of Environmental Science International
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    • 제21권10호
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    • pp.1255-1263
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    • 2012
  • Batch cultivations were performed to evaluate the influences of the initial pH condition on mesophilic and thermophilic acidogenic fermentation with food waste recycling wastewater. In both conditions of mesophilic and thermophilic fermentation, TVFAs production rates were maximized at the initial pH 7 condition as 0.15 and 0.23 g TVFAs/L hr, respectively. And pH was also maintained stably between 6 and 7 during 72hr acidogenic cultivation at both conditions. However, predominant VFA components were different according to reaction temperature conditions. In mesophilic condition, propionic acid which has low conversion efficiency to methane was accumulated up to 1,348 mg/L while acetic and butyric acid were predominant in thermophilic condition. Therefore, thermophilic acidogenic fermentation was superior for the effective VFAs production than mesophilic condition. From the DGGE analysis, the band patterns were different according to the initial pH conditions but the correlations of the each band were increased in similar pH conditions. These results mean that microbial communities were certainly affected by the initial pH condition. Consequently, the adjustment of the initial pH to neutral region and thermophilic operation are needed to enhance acidogenic fermentation of food waste recycling wastewater.

Identification of Aroma-Active Compounds in Korean Salt-Fermented Fishes by Aroma Extract Dilution Analysis 2. Aroma-Active Components in Salt-Fermented Shrimp on the Market (AEDA법에 의한 한국한 젓갈류의 Aroma-Active 성분의 구명 2. 시판 새우젓의 Aroma-Active 성분)

  • Cha, Yong-Jun;Kim, Hun;Jang, Sung-Min;Park, Jee-Young
    • Journal of the Korean Society of Food Science and Nutrition
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    • 제28권2호
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    • pp.319-325
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    • 1999
  • Volatile flavor compounds in Korean salt fermented shrimp on the market were analyzed by vacuum simultaneous distillation solvent extraction/gas chromatography/mass spectrometry/olfac tometry(V SDE/GC/MS/O) and aroma extract dilution anlaysis(AEDA). A total of 32 volatile com pounds were detected by GC/O analysis. Of these, 18 were positively identified, and composed of S containing compounds(5), aldehydes(4), ketones(3), N containing compounds(3), ester(1), alcohol(1) and aromatic hydrocarbon(1). Predominant odorants(Log3FD$\geq$4) in salt fermented shrimp were 2,3 butanedione(sour/buttery), 1 octen 3 one(earthy/mushroom like), dimethyl trisulfide(cooked cabbage /soy sauce like) and 2 acetylthiazole(grainy/nutty). Predominant free amino acids were aspartic acid, glutamic acid(sour and umami taste), arginine, methionine(bitter) and lysine(sweet and bitter) in evaluation of taste value.

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Differences in Time Deficit and Time Satisfaction According to the Types of Child Care Time of Dual-earner Couples with Preschool Children (미취학자녀를 둔 맞벌이부부의 자녀양육시간 유형에 따른 시간부족감 및 시간사용만족도의 차이)

  • Park, Eun Jung;Lee, Seong-Lim
    • Journal of Families and Better Life
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    • 제31권4호
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    • pp.97-111
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    • 2013
  • The purpose of this study was to explore the typology of child care, investigate the characteristics of child care types, and analyze the differences in time deficit as well as time satisfaction by the types of child care for dual-earner couples with preschool children. The data source for this research was the 2009 Time Use Survey conducted by the Korea National Statistical Office. Dual-earners aged 20 to 59 years completed 1,568 time diaries, which were analyzed using chi-square, cluster analysis, and ANOVA analysis. Child care time was classified into three types in the three categories of child care, household work sharing and leisure sharing for both males and females respectively. Three types for husbands were named "vulnerable", "household work child care predominant" and "leisure predominant". The three types for wives were named "vulnerable", "household work child care oriented" and "household work child care". The characteristics of each type depended on age, education, weekly working hours, gender role of husbands and age, weekly working hours of wives. The vulnerable type of wives showed the highest level of time deficit. Based on the results, implications for Public policy on child care and various types of education as well as programs were suggested.

Reference research for the cause of facial nerve paralysis (구안괘사의 원인(原因)에 대(對)한 문헌적(文獻的) 고찰(考察))

  • Yu, Han Chol;Kim, Han Sung
    • Journal of Haehwa Medicine
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    • 제9권1호
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    • pp.243-258
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    • 2000
  • From the reference research, the results obtained were as follows. 1. Until the "Song" dynasty, the predominant cause of facial nerve paralysis was the attack of Pathogenic Wind to "the Stomach Channel of Foot Yangming, (St.C.); and "the Small Intestine Channel of Hand Taiyang, (S.I.C.). They recognized the facial paralysis as an aspect of palsy. 2. In the period of Jin-Yuan(金元), the predominant cause was described as "Xuexu"(the deficiency of blood) and phlegm. They recognized that the facial palsy was a palsy. However, they also acceded to the possibility that there could be other explanations. 3. In the period of "Ming & Qing", there were numerous kinds of causes. For example, the following were identified as attacking the Meridian: the Pathogenic Cold; Pathogenic Heat; "Xinxu"(the deficiency in the heart); Fire and Heat combined as a pathogenic factor; "Pixu"(the deficiency in the spleen); and, "Xinxu"(the deficiency of blood). 4. In the past, Koreans have explained the facial paralysis according to the Chinese theories mentioned. However, recently there has been an emergence of another Chinese theory; whereby, facial paralysis is classified into causes and symptoms, and then medical treatment is applied accordingly. 5. From the occident medical perspective, the facial paralysis is categorized into two causes. The first is called central facial nerve paralysis and the second is called peripheral facial nerve paralysis. The latter is mainly caused by Bell's palsy, Herpez zoster oticus, and trauma.

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On the Hull Vibration of the Training Ship Sae-Ba-Da (실습선 새바다호의 선체진동에 관하여)

  • Park, Jung-Hui
    • Journal of Korea Fishing Vessel Association
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    • 제29권
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    • pp.15-20
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    • 1986
  • This paper describes on the measurement of the deck vibration produced by the main engine vibration of stern trawler MIS SAE-BA-DA (2,275GT, 3,600PS) while the ship is cruising and drifting. The obtained results are as follows; 1. The deck vibration level was the highest point at vertical line which pass main engine and the lowest point at vertical line which pass top bridge while the crusing. 2. The vibration source level of the main engine, screw shaft and screw propeller were respectively 110, 90 and 80% while the crusing. 3. The main deck vibration pressure level at the check points 2, 20, 30, 40, 60, 70, 80, 86m from the bow to stern was respectively 9, 8, 7, 10, 22, 45, 18, 23%. 4. The frequency distributions of the main engine, screw shaft, screw propeller vibration were from 3Hz to 10KHz, predominant frequency was 1KHz, each vibration accelration the highest level were respectively 1.3, 0.8, 0.5mm/$S^2$. 5. The predominant frequency distributions of the main deck, second deck, bridge deck and top bridge deck's vibration were from 10 to 30Hz, and each vibration accelration level were respe¬ctively 0.7, 0.05, 0.07, 0.04mm/$S^2$.

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Studies on Chromosome Aberrations Induced N-ethyl-N-nitrosourea and N-methyl-N-nitrosourea in CHO cells (N-ethyl-N-nitrsourea와 N-methyl-N-nitrosourea에 의한 CHO 세포의 염색체 이상에 관한 연구)

  • Kim, Choon-Kwang
    • The Korean Journal of Zoology
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    • 제24권3호
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    • pp.163-171
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    • 1981
  • Chromosome aberrations induced by ENU and MNU were investigated in CHO cells at various doses and times after treatment. The results obtained were as follows: The frequency of chromosome aberrations induced by ENU and MNU drastically depends on the length of the post-treatment period and the concentration of these chemicals. In ENU-treated groups, the major type of aberration was chromatid deletions in earlier samples but the frequency of chromatid exchanges increased with time, revealing, predominant type at 24 hours after treatment with $10^-3$ M. In MNU-treated groups, chromatid deletions were also major type but frequency of chromatid exchanges were predominant from 12 hours after treatment with $10^-4$ and $10^-5$ M.

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Seasonal Variations of Nutrients in Warty Sea Squirt(Styela clava) (계절에 따른 미더덕의 영양성분 조성에 관한 연구)

  • 이강호;박천수;홍병일;정병천;조호성;제외권
    • Journal of the Korean Society of Food Science and Nutrition
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    • 제24권2호
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    • pp.268-273
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    • 1995
  • To study the nutritional value of warty sea squirt, Styela clava, which is one kind of urochoda and it has been used as special seafood stuffs by Korean, the seasonal variations of nutrient was investigated. The moisture content was ranged from 83.6% to 86.8% in experimental period. Maximun glycogen content showed up in June (3.7g/100g sample). The protein(N$\times$6.25) and lipid content varied with glycogen whereas ash content was not changed remarkably, showing 2.8$\pm$0.3%. Predominant minerals in edible portion and integuments were sodium, potassium, calcium and magnesium in order. Predominant constitutiional amino acids were asparagine, glutamic acid, taurine, aspartic acid, lysine and glycine and amino acids occupied 50% of the total amino acid. Porportion of nonpolar lipid to total lipid increased from April to early June while polar lipid level decreased. The neutral lipid was composed of triglyceride(59.32%) and free sterol(23.52%), and followed by diglycerides, monoglycerides, esterified sterols and hydrocarbon, free fatty acid. The phospholipid was mainly composed with phosphatidyl choline(49.7%), and phosphatidyl ethanolamine(33.0%). The major fatty acids of the total lipid in warty sea squirt were C20 : 5(17%), C22 : 6(13.76%), C16 : o(13.91%) and C16 : 1(12.52%).

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High Temperature Tribological Behaviour of Particulate Composites in the System SiC-TiC-TiB2 during Dry Oscillating Sliding

  • Wasche, Rolf;Klaffke, Dieter
    • The Korean Journal of Ceramics
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    • 제5권2호
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    • pp.155-161
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    • 1999
  • The tribological behaviour of monolithic SiC as well as SiC-TiC and SiC-TiC-$TiB_2$ particulate composite materials has been investigated in unlubricated oscillating sliding tests against $Al_2O_3$ at temperature in the range from room temperature up to $600^{\circ}C$. At temperatures below $600^{\circ}C$ the wear rate of the systems with the composite materials was up to 20 times lower than the wear of the $Al_2O_3$/SiC system and was dominated by the oxidation of the titanium phases. At $600^{\circ}C$ the oxidation rate of the TiC and -TEX>$TiB_2$ grains becomes predominant resulting in an enhanced wear rate of the composite rate of the TiC and TiB2 grains becomes predominant resulting in an enhanced wear rate of the composite materials. The coefficient of friction shows similar values for all materials of investigation, increasing from 0.25…0.3 at room temperature to 0.7…0.8 $600^{\circ}C$. The wear of the $Al_2O_3$/SiC system is mainly abrasive at temperatures above room temperature and is characterised by an enhanced wear of the alumina ball at $600^{\circ}C$.

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Changes in Lactic Acid Bacteria of Squid with Low Salt during Fermentation (저염 오징어젓갈 숙성중 젖산균의 변화)

  • Jo, Jin-Ho;Oh, Se-Wook;Kim, Young-Myoung;Chung, Dong-Hyo;Kim, Joung-Im
    • Korean Journal of Food Science and Technology
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    • 제29권6호
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    • pp.1208-1212
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    • 1997
  • Isolation and identification of predominant microorganisms in fermented squid with low salt were carried out during fermentation at $10^{\circ}C$. Dominant strains were lactic acid bacteria(80%) including Lactobacillus plantarum, Lactobacillus brevis, Leuconostoc sp., Pediococcus sp. and Streptococcus sp. Leuconostoc, Pediococcus and Streptococcus were shown in the early stage of fermentation and gradually increased until optimum stage of squid fermentation, and then decreased rapidly. Lactobacillus grew lastingly during fermentation. Yeasts were detected in the middle stage of fermentation and shown rapid increase after the last stage of fermentation, suggesting that yeasts participate in putrefaction of fermented squid with low salt.

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Bacterial Community Variations in Hot Pepper-Sown Soil Using FAME Analysis as an Indicator of Soil Quality

  • Kim, Jong-Shik;Weon, Hang-Yeon;Kwon, Soon-Wo;Ryu, Jin-Chang
    • Journal of Microbiology and Biotechnology
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    • 제13권2호
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    • pp.251-255
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    • 2003
  • The bacterial compositions of seven hot-pepper sown soil were compared in this study. From the 624 isolates, 95 species and 49 genera were identified by fatty acid methyl ester analysis (FAME). The FAME results of seven soil showed two distinct clusters for aerobic and Gram-negative bacteria in the high productivity and monoculture soil samples. While Arthrobacter ($17\%$), Kocuria ($11\%$), Pseudomonas ($8\%$), and Bacillus ($8\%$) were predominant among bacteria which were cultured on heterotrophic (YG) agar medium, Pseudomonas ($56\%$), Stenotrophomonas ($16\%$), and Burkholderia ($8\%$) were predominant on crystal violet agar medium. Shannon Weaver indices (H) indicated that colonies obtained from heterotrophic agar medium (3.1) were found to be more diverse than those obtained from the crystal violet media (1.9). The results suggest that FAME analysis may be a potential indicator for of soil quality.