• Title/Summary/Keyword: constant temperature

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Changes in Microbial Counts, Enzyme Activity and Quality of Foxtail Millet Yakju Treated with High Hydrostatic Pressure During Storage (초고압 처리한 좁쌀약주의 저장 중 미생물수, 효소활성 및 품질변화)

  • 임상빈;좌미경;목철균;박영서
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.3
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    • pp.576-581
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    • 2004
  • Foxtail Millet Yakju were treated with heat ($65^{\circ}C$/15 min) or high hydrostatic pressure ($25^{\circ}C$ (RT) and $65^{\circ}C$ (HT)/400 MPa/10 min), and stored for 64 days at l$0^{\circ}C$, $25^{\circ}C$ and 37$^{\circ}C$. Changes in microbial counts, enzyme activity and quality of Yakju during storage were measured. Total viable cells were about 10$^2$ CFU/mL, and remained almost constant during storage at l$0^{\circ}C$ and $25^{\circ}C$, while decreased significantly at 37$^{\circ}C$, and undetected after 55 days of storage in heat- and pressure(RT)-treated, but after 25 days in pressure(HT)-treated Yakju. Lactic acid bacteria and yeast in heat- and pressure-treated Yakju were not detected during storage. The relative activities of a -amylase in heat- and pressure(RT)-treated were more than 100%, while those in pressure(HT)-treated were less than 40% during storage of 64 days at l$0^{\circ}C$. However, at $25^{\circ}C$ and 37$^{\circ}C$ the relative activities in untreated and pressure(RT)-treated were decreased greatly and then reached at the point of the activities of heat- and pressure(HT)-treated. The relative activities of glucoamylase in untreated and pressure(RT)-treated were decreased as the increase of the storage temperature during storage, while those in heat- and pressure(HT)-treated increased slightly as the increase of storage period at 1$0^{\circ}C$ and $25^{\circ}C$, and had no change at 37$^{\circ}C$. pH in heat- and pressure-treated had almost no change. Turbidity and reducing sugar in heat- and pressure-treated increased as the increase of storage temperature during storage.

Effects of Pre-slaughter Fasting and Chiller Ageing on Objective Meat Quality in Longissimus Dorsi, Biceps Femoris, and Triceps Brachii Muscles of Korean Native Black Pigs (도축전 절식과 냉장숙성이 재래돼지 Longissimus Dorsi, Biceps Femoris와 Triceps Brachii의 육질에 미치는 영향)

  • Hwang, I.H.;Park, B.Y.;Cho, S.H.;Kim, M.J.;Lee, J.M.
    • Journal of Animal Science and Technology
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    • v.46 no.3
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    • pp.405-414
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    • 2004
  • This study evaluated the effects of preslaughter feed withdrawal and chiller ageing on objective meat quality traits in longissimus dorsi (LD), biceps femoris(BF), and triceps brachii(TB) muscles of Korean native black pigs. Twenty males were assigned into a 2(pre-slaughter feeding) ${\times}$ 2(pre-slaughter stress) ${\times}$ 4(chiller ageing) factorial. Pre-slaughter fasting for 18 h resulted in significantly(P < 0.05) higher pHs at 1.5 h for both LD and BF. On the other hand, muscle temperature did not differ between the fasted and fed animals. The result implied that pigs with different pre-slaughter feedings experienced different pH-temperature profiles during rigor development. This was reflected by the significan(P < 0.05) increase in cooking loss and hunter $L^*$ for LD of the fed pigs. However, WB-shear force of LD was not affected by the treatment. Furthermore, objective meat quality of BF and TB did not differ between the treatments. Hunter $L^*$ value and cooking loss for LD were constant for 7 d, followed by a significant(P < 0.05) increase at 14 d. BF and TB had significantly(P < 0.05) higher hunter $L^*$ value and cooking loss at 14 d than at 1 d. Significant(P < 0.05) linear reductions in LD WB-shear force took place from 1 to 7 d, while BF and TB WB-shear forces were significantly (P < 0.05) reduced at 14 d. Simple correlation for WB-shear force between LD and BF, and between LD and TB indicated that 6 kg of shear force for LD was equivalent to approximately 3.5 and 6 kg for TB and BF, respectively. On the basis of the current result, feeding until the morning of slaughter appeared to contribute to favourable meat color for LD. However, negative effect on palatability due to increase in cooking loss should be taken into account. A 7-d chiller ageing was likely the best practice for LD, while TB appeared not to require chiller ageing. A 14-d ageing could improve the tenderness of BF, but could likely reduce juiciness.

A Study on Changes of Physico-Chemical Properties of Plow Layer Soil and its Response of Tobacco Growth under Poly Ethylene Film Mulching Condition. -2. Effect of Poly Ethylene Film Mulch on the Mineralization of Compound Fertilizer and Mobility of Mineralized Nutrients in the Plow Layer (연초피복재배(煙草被覆栽培)에서 작토층(作土層)의 이화학성(理化學性) 변화(變化)와 연초생장반응(煙草生長反應)에 관(關)한 연구(硏究) -2. 피복조건(被覆條件)이 시비(施肥)된 비료(肥料)의 무기화작용(無機化作用)과 무기화(無機化)된 양분(養分)의 작토층위별(作土層位別) 이동(移動)에 미치는 영향(影響))

  • Hong, Soon-Dal;Lee, Yun-Hwan;Kim, Jai-Joung;Cho, Seong-Jin
    • Korean Journal of Soil Science and Fertilizer
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    • v.18 no.2
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    • pp.140-147
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    • 1985
  • This experiment was conducted in the field to investigate the effects of mulched condition on nutrient's mineralization and its mobility as affected by environmental changes (soil moisture and soil temperature) in the plow layer. 1. Nitrogen mineralization was faster owing to the prevention of evaporation and the increase of soil temperature in the poly ethylene mulched plot. As a result, nitrate form of nitrogen was much earlier available for plant in mulched plot than in non mulched plot. 2. Available $P_2O_5$ content in the plow layer was kept highest in the fertilized zone (10-20 cm depth) regardless of difference between mulched and non mulched condition, and was nearly constant without showing difference between planting and non planting of tobacco due to the lower availability of phosphorus by tobacco. 3. Potassium applied in the plow layer was remained a large quantity until the latter growth stage resulting in the lower recovery of potassium by tobacco. 4. Mineralized nutrients such as $NH_4-N$, $NO_3-N$, and K in the plow layer of mulched plot were transported from the fertilized layer (10-20 cm depth) and accumulated to the surface layer (0-10 cm depth) as the growing time goes by, but those in non mulched plot were distributed to the deeper layer. 5. Mobility of available nutrients in the plow layer was If order as $NO_3-N$ $$\geq_-$$ $NH_4-N$ > K > available $P_2O_5$. 6. Leaching degree of mineralized nutrients in the mulched plot was much lower than in the non mulched plot.

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Studies on utilization of agricultural waste products -Part 3. Separation of phytin from defatted rice bran- (농업부산물(農業副産物)의 이용성향상(利用性向上)에 관(關)한 연구(硏究) -제3보(第3報) 탈지미강(脫脂米糠)부터 phytin 분리(分離)-)

  • Shin, Jai-Doo
    • Applied Biological Chemistry
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    • v.9
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    • pp.71-81
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    • 1968
  • Defatted rice bran is mixed with diluted acid solution, the mixture is agitated some hrs. at constant temparature. After the mixture is filtered, thus filtrate is obtained. This filtrate is phytin extract solution. (Test-1) The alkali is added to this filtrate and filtered out, then the precipitation of phytin is obtained. (Test-2) At the test-1, the effect of kind of acid, conc. of acid, amount of extract sol'n., time of extraction, temp. of extraction, to the extract amount of phytin is tested. Consequently, the following facts are known. 1. Amount of phytin extract is greater HCI extraction than $H_{2}SO_4$ extraction. 2. At 0.3% HCI, the amount of phytin extract is greatest of all HCl extraction. 3. The sufficient amount of acid solution is 8-10 times of amount of defatted rice bran. 4. The time of extraction at room temperature is sufficient 8-12 hrs. 5. When extract temperature is $20-30^{\circ}C$, the amount of phytin extraction is greater of all temp. 6, When defatted rice bran 20 g is shanken with 160 ml of 0.3% HCl for 10 hr. at room temp., in this case the amount of phytin extract is 11.34% of defatted rice bran, it is 93% of theoretical yield. At the test-2 the effect of kind of precipitation agent, degree of nutralization to the amount of phytin prcipitation is tested. 1. Degree of nut. is best at pH 6.8-7.0. 2. When use of $Ca(OH)_2$ the amount of phytin precipitation is more than use of KOH, NaOH, or $NH_{4}OH$. 3. At pH 6.0-7.2, the solubility of phytin is followed. K-phytate > $NH_{4}-phytate$ > Na-phytate > Ca-phytate 4. When phytin extract solution is nutralized with $Ca(OH)_2$ to pH 7.0, the amount of phytin precipitation is 94.78% of theoretical yield.

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A Survey of the Kumho River Pollution (금호강 오염의 종합적 조사)

  • Bae, Zun-Ung;Lee, Sang-Hak;Lee, Sung-Ho
    • Analytical Science and Technology
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    • v.15 no.1
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    • pp.54-66
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    • 2002
  • In order to study systematic survey of Kumho river pollution, water analysis for 24 items was conducted at 16 sites surrounding the Kumho river system for 3 times from May 2000 to February 2001. Analytical items for the study of water quality are as follows; water temperature, pH, BOD, COD, DO, SS, electrical conductivity, oil & grease, ABS, phenol, T-P, ${PO_4}^{3-}-P$, T-N, $NH_3-N$, ${NO_2}^--N$, ${NO_3}^--N$, Cu, Zn, Cr, Cd, Mn, Fe, Pb and As. The mean values obtained for water temperature, pH, BOD, COD, DO, SS, electrical conductivity, oil & grease, ABS, phenol T-P, T-N, Cu, Zn, Fe and Mn showed $17.84^{\circ}C$, 8.04, $2.54{\mu}g/mL$, $5.64{\mu}g/mL$, $7.07{\mu}g/mL$, $8.75{\mu}g/mL$, $600.4{\mu}S/cm$, $0.19{\mu}g/mL$, $0.015{\mu}g/mL$, $0.29{\mu}g/mL$, $0.21{\mu}g/mL$, $5.22{\mu}g/mL$, $0.005{\mu}g/mL$, $0.007{\mu}g/mL$, $0.044{\mu}g/mL$ and $0.001{\mu}g/mL$ respectively. As, Cd, Cr and Pb are not detected. The mean concentration of phenol, $NH_3-N$ and $NO_2-N$ were found to be increased compared to the prior study for 3 years from January 1997 to December 1999, that of BOD, COD, SS, oil & grease and ABS were found to be decreased and the others are nearly constant. The effect of Kumho river to the Nakdong river pollution are as follows. The mean concentration of BOD changed from $1.07{\mu}g/mL$ to $1.42{\mu}g/mL$ before and after of introducing of Kumho river water respectively. The mean concentration of COD, electrical conductivity, oil & grease, ABS, phenol, T-N and T-P changed from $1.99{\mu}g/mL$, $221{\mu}S/cm$, $0.15{\mu}g/mL$, $0.006{\mu}g/mL$, $0.06{\mu}g/mL$, $2.21{\mu}g/mL$ and $0.08{\mu}g/mL$ to $2.44{\mu}g/mL$, $392{\mu}S/cm$, $0.16{\mu}g/mL$, $0.015{\mu}g/mL$, $0.07{\mu}g/mL$, $2.81{\mu}g/mL$ and $0.19{\mu}g/mL$ respectively.

Energy Budgets for the Developmental Stages of Palaemon macrodactylus (Palaemon macrodactylus의 생활사에 따른 에너지 수지)

  • CHIN Pyung;KIM Heung-Yun;SIN Yun-Kyong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.25 no.5
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    • pp.341-358
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    • 1992
  • In order to estimate energy budgets of Palaemon macrodactylus, larvae of the shrimp were reared in the laboratory at constant conditions $(25^{\circ}C: 31-32\%o),$ and then juvenile to adult of the shrimp were reared at $15^{\circ}C\;and\;25^{\circ}C$ in the laboratory. Energy used by the reared shrimps were calculated from estimates of data on feeding, growth, molting, metabolism, nitrogen excretion, and energy content. Juveniles and adults reared in the laboratory, which fed on Artemia nauplii, had an average daily growth rates of 0.079 mm/day at $15^{\circ}C\;and\;of\;0.122mm/day\;at\;25^{\circ}C$. The average growth factor* of P. macrodactylus males and females ranged from $3.2\%$ for adult to $13.2\%$ for juveniles individuals, respectively. Intermolt periods were related to body size of the shrimp and to temperature. Average laboratory growth curves were calculated from data on growth factors and intermolt periods to body size of the shrimp at $15^{\circ}C\;and\;25^{\circ}C$. The calorie contents of the shrimp, their molts, eggs and larvae were determined by biochemical composition and oxygen bomb calorimetry. The average amount of energy used in growth for larvae and juvenile to adult were 4.94 cal and 4.55 cal per dry weight in milligram, respectively. The ammount of oxygen used in metabolism was calculated from size, temperature-specific respiration rate. To convert the ammount of oxygen used in respiration into the equivalent energy lost heat was estimated from the data on chemical composition for the larvae and adult, the values was 4.58 cal/ml $O_2$. The energy content per egg was 0.078 cal. The assimilation efficiency estimated by nitrogen content of food and egested faeces gave $61.5\%$ for the larvae. The efficiencies for juvenile to adult ranged between $79.4\%$ and $90.1\%$ The gross growth efficiencies $(K_1)$ and net growth efficiencies $(K_2)$ of P macrodactylus showed $18.33\%\;and 32.63\%$ for total larval stages, ranged from $21.30\%\;to\;31.04\%\;and\;from\;30.03\%\;to\;39.34\%$ for juvenile to adult, respectively.

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A study on the crystallographic and magnetic Properties of Ce doped Garnet (Ce이 치환된 YIG garnet의 결정학적 및 자기적 성질 연구)

  • Kum, Jun-Sig;Kim, Sam-Jin;Shim, In-Bo;Kim, Chul-Sung
    • Journal of the Korean Magnetics Society
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    • v.14 no.1
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    • pp.46-50
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    • 2004
  • Compounds of $Y_{3-x}Ce_{x}Fe{5}O_{12}$(x=0.0, 0.1, 0.2, and 0.3) were prepared using the sol-gel method. The XRD measurements show that these samples have only a single phase of the garnet structure regardless of the amount of Ce substitution. The lattice constants of x = 0.0 and x = 0.3 were found to be a$_0$ = 12.3758 ${\pm}$0.0005 ${\AA}$ and 12.4062 ${\pm}$0.0005 ${\AA}$, respectively. The lattice constant increases linearly with increasing Ce concentration. The saturation magnetization was not changed flirty, with increasing Ce concentration, but coercivity decreased form 18.3 Oe to 5.8 Oe as x increased form x = 0.0 to x = 0.1. Mossbauer spectra of $Y_{3-x}Ce_{x}Fe{5}O_{12}$ were measured at various absorber temperatures from 13 K to Neel temperature. The Mossbauer spectra were fitted by least-squares technique with two subpatterns of Fe sites in the structure and corresponding to the 16a and 24d site. The temperature dependence of the magnetic hyperfine field in $^{57}$/Fe nuclei at the tetrahedral 240 and octahedral 16a sites were analyzed based on the Neel theory of ferrirnagnetism. The result of the Debye temperatures indicated that the inter-atomic binding force for the 24d site was larger than that for the 16a site.

Variation of Seed Germination Among Cultivated and Weedy Types of Perilla Crop in Korea and Japan (한국, 일본에서 수집한 들깨와 차조기의 재배형 및 잡초형들의 종자발아 변이)

  • Jung, Ji-Na;Yu, Chang-Yeon;Kim, Jong-Hwa;Lee, Ju-Kyong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.54 no.3
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    • pp.270-278
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    • 2009
  • To understand the seed characteristics among cultivated types of Perilla crop and their weedy types in Korea and Japan, we studied the variation of 69 accessions by examining weight of 100 seeds, hardness of seed, germination percent and germination energy. The survey of the weight of 100 seeds and hardness of seed, clarified as follows; cultivated type of var. frutescens showed a range of 0.177 to 0.402 g with weight of 100 seeds, and most accessions of cultivated type of var. frutescens have soft seeds, except for several accessions, which have hard seeds, whereas weedy type of var. frutescens showed a range of 0.045 to 0.172 g with weight of 100 seeds, and has only hard seeds. While cultivated type of var. crispa showed a range of 0.054 to 0.101 g with weight of 100 seeds, and has only hard seeds. The weedy type of var. crispa showed a range of 0.059 to 0.135 g with weight of 100 seeds, and has only hard seeds. According to the result of germination tests, although the most accessions of cultivated and weedy types of var. frutescens and cultivated and weedy types of var. crispa showed below 50% germination rate at the first germination test, but some accessions of cultivated type of var. frutescens showed above 50% germination. While, in the second or third germination tests, most accessions of cultivated types of Perilla crop and their weedy types showed above 50% germination rates, except for several accessions. As a result, in this study, the average of germination percent and germination energy among accessions of cultivated types of Perilla crop and their weedy types showed respectively the highest value at the third germination test, but showed the lowest value at the first germination test. In addition, the germination percent and germination energy showed much higher in the room temperature condition than in $28^{\circ}C$ constant-temperature condition. Although our results may be required much clearly survey in the further study, this current results will be help for our understanding the variation of seed characteristics among cultivated types of Perilla crop and their weedy types in Korea and Japan.

Engineering Characteristics of Wet-mixing Solidified Soil in Pavement Surfacing (습식 경화교반토 포장의 공학적 특성)

  • Yoo, Ji-Hyeung;Shu, Dong-Hyuk;Lee, Seong-Won
    • International Journal of Highway Engineering
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    • v.6 no.3 s.21
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    • pp.1-7
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    • 2004
  • Roads, like bikeways, parkways and walks, are to be just capable of supporting light traffic and traveling public, but they are required to be human friendly and environmental-oriented. Lately soil-solidifier mixture, a kind of soil-cement, has developed and has been applied to the recycling and environment-oriented pavement as the surfacing material. Soil-solidifier pavement structure has been designed by only experience. To design this pavement mechanically, it is necessary to find out basic engineering properties of soil-solidifier mixture. This study focuses on finding out mechanical characteristics of the mixture according to mixture proportions and aging. Test molds with various mixture proportions are made, and then unconfined strength tests are performed for test molds with aging of the mixture. As the result of this study, it is found that the strength of the mixture increases with amount of cement and that maximum strength is achieved at 6%$\sim$8% of the ratio of solidifier and water. The strength increase rapidly until 14 days, after then slowly. After 28 days the strength of the mixture approaches to the constant value. The heat of hydration during curing of the mixture is measured no significantly. It also shows that temperature characteristics of the mixture is similar to that of soil. Since this mixture is mixed with soil and is able to improve engineering problems in pavement due to temperature, this mixture is expected to use effectively in the environment-oriented pavement for light traffic.

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Determination of Hydrolysis Rate Constants on Phosphamidon and Profenofos (Phosphamidon과 Profenofos의 가수분해속도 상수의 측정)

  • Min, Kyung-Jin;Ha, Young-Duck;Seo, Seol;Cha, Chun-Geun;Park, Jang-Woo;Lee, Seung-Gon
    • Journal of Food Hygiene and Safety
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    • v.15 no.2
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    • pp.144-150
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    • 2000
  • The present study was peformed to determine the hydrolysis rate constants and degradation products of phosphamidon and proffnofos by the OECD method. Hydrolysis rate constants of phosphamidon in pH 4, pH 7, and pH 9 buffer solutions at 25 and 40$^{\circ}$C were 0.0020, 0.0022, 0.0049 and 0.0040, 0.0050, 0.0150, respectively. Hydrolysis rate of phosphamidon was accelerated by temprerature change under same pH conditions, and half-life of phosphamidon in pH 9 at 40。C was 3 times faster than that at 25。C. Hydrolysis rate of phosphamidon in alkaline solution(pH 9) was 2~4 times faster than that in acidic solution(pH 4) and neutral solution(pH 7) under same temperature. Hydrolysis rate constants of profenofos in pH 4, pH 7, and pH 9 buffer solutions at 25 and 40。C were 0.0022, 0.0047, 0.0860 and 0.0035, 0.0086, 0.1245, respectively. Hydrolysis rate of profenofos was accelerated by temprerature change under same pH conditions. Hydrolysis rate of profenofos in alkaline solution(pH 9) was 15~40 times faster than in acidic solution(pH 4) and neutral solution(pH 7) under same temperature condition, and half-life of profenofos was very fast within 8 hours. The hydrolysis rate of profenofos was faster than that of phosphamidon. In order to identify hydrolysis products, the extracts of degradation products were analyzed by GC/MS. The mass spectra of hydrolysis products of phosphamidon were at m/z 153 and 149, those of the profenofos were at m/z 208 and 240, respectively. The hydrolysis products of phosphamidon were O, O-dimethyl phosphate(DMP) and N, N-diethylchloroacetamide, and those of profenofos were 4-bromo-2-chlorophenol and O-ethyl-S-propyl phosphate.

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