• Title/Summary/Keyword: Test Temperature

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DISTRIBUTION AND PHYSIOLOGICAL CHARACTERISTICS OF BACILLUS CEREUS IN RICE AND RICE PRODUCTS (미반류에 있어서 Bacillus cereus균의 분포와 생리적특성에 관한 연구)

  • LEE Myeong-Sook;CHANG Dong-Suck
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.13 no.4
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    • pp.163-171
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    • 1980
  • Recently, Bacillus has been identified as one of food poisoning bacteria especially in products of cereal foods in foreign countries. Therefore, the quantitative distribution of Bacillus cereus in market foods, its physiological characteristics, growth rate by temperature and heat resistance of its spore were examined. Thirty two samples of cooked rice, 20 samples of kimbab(cooked rice rolled with laver), 23 samples of rice cake, 13 samples of rice ana 13 samples of barley were collected from restaurents and food stores in Busan, Korea during the period from May to November in 1980. Forty samples of 101 samples submitted to the test appeared positive for Bacillus cereus showing abut $40\%$ in detection ratio. Detection ratio of Bacillus cereus was higher than $50\%$ in barley and rice, and about $30\%$ in rice products. Average Bacillus cereus content of in the samples was $2.6\times10^6/g$ in cooked rice, $2.3\times10^6/g$in kimbab, $4.9\times10^4/g$ in rice cake while that in rice and barley was about $10^3/g$. The result of biochemical tests of the bacterium was $100\%$ positive in catalase, egg yolk reaction, gelatin hydrolysis and glucose fermentation, $100\%$ negative in xylose, arabinose and mannitol oxidation, about $90\%$ positive in acetoin production, $80.0\%$ positive in nitrate reduction and citrate utilization and $55.0\%$ positive in starch hydrolysis test. Isolation ratio of Bacillus ceresus which showed haemolysis positive and starch hydrolysis negative results, was about $38\%$ in 40 strains examined. It is known that those strains has a close relation to food poisoning accident. Growth rate and generation time of Bacillus cereus isolated from the cooked rice were $0.34hr^{-1},\;2.02hr\;at\;20^{\circ}C,\;0.73hr^{-1},\;0.95hr\;at\;30^{\circ}C\;and\;0.49hr^{-1},\;1.44\;hr\;at\;40^{\circ}C$ respectively. Heat resistance value of Bacillus cereus spores suspended in phosphate buffer solution was $D_{90}=29.0min,\;D_{95}=8.7min,\;D_{98}=3.7\;min\;and\;D_{101}=2.3\;min(z=10.5)$.

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Immobilization of Xylose Isomerase and Trial Production of High Fructose Corn Syrup (Xylose 이성화 효소의 고정화 및 이성화당의 생산)

  • Chun, Moon-Jin;Lim, Bun-Sam
    • Applied Biological Chemistry
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    • v.26 no.4
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    • pp.222-230
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    • 1983
  • This study was designed to develop a process for the immobilization of xylose isomerase(D-xylose ketol isomerase, EC 5.3.1.5) from Streptomyces griseolus previously isolated by the authors and its application on a pilot plant scale for the production of high fructose corn syrup. The biomass which has endo-excreted xylose isomerase was homogenized under a pressure of $500kg/cm^2$ and 90.8% of the enzyme recovery of the native activity was obtained as compared to 54.7% recovery by the lysozyme treatment. Ionic bonding method was adopted for the enzyme immobilization due to its many reported merits. It was found that the porous resins such as Diaion HP 20, Duolite A-7, Amberlite IRA 93 and 94 were effective in immobilizing the enzyme. In addition, it was disclosed that the regeneration form of $BO_4--$ is effective for Amberlite IRA 93 and $HCO_3-$ for Diaion HP 20. Optimal immobilization condition for Amberlite IRA 93 was pH 8.0 and $55^{\circ}C$ yielding 80.6% of immobilization. Activity decay test showed half life of the immobilized enzyme with Amberlite IRA 93 was more than 24 days at $65^{\circ}C$. The carrier was evaluated to be resuable and its result showed the relative immobilization yields were 98.2, 93.3, 90.7 and 87.5%, respectively at second, third, forth and fifth rebinding test of the enzyme on Amberlite IRA 93. Optimal temperature of the immobilized enzyme was slightly lowered and the range widened to $60\sim70^{\circ}C$, while optimal pH moved toward $8.0\sim8.3$ in its isomerization reaction. The trial production result of high fructose corn syrup in pilot scale immobilization showed that one liter of immobilized xylose isomerase (350 IXIU/ml-R) is capable producing about 293l high fructose corn syrup(75% dry substance) in 30 days.

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A Study on Preventive Methods Against Concrete Corrosion by Sea Water of the of West Sea (서해조수에 의한 콘크리트의 부식 방지법에 관한 연구)

  • 고재군
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.14 no.2
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    • pp.2622-2633
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    • 1972
  • This study was attempted in order to search for phyosical properties on various mix designs of concrete as ne of studies relating top revention against corrosion by action of sea water in the West Sea. In this study, as concerete mix design, fly ash, pozzolith and vinsolresin were used as admixtures for normal portland cement respectively, and pozzolan cement and normal cement were also used for each plain concrete. Concrete specimens were made and cured in accordance with the Korean Standard Specifications for concrete. In thetest, compressive strengths of the specimens were measured at the following ages; 7-day, 28-days and 3-months. Absorption test was made by immersing the specimens in water kept at boiling temperature for 5 hours. The results obtained from the tests are summarized as follows; 1. The use of fly ash as an admixture in mix design of concrete, has an effect on compressive strength at each age. But it is actually not effective on absorption by concrete, as the result of the fly ash concrete is almost the same at that of ordinary plain concrete. 2. The use of pozzolith as an admixture in mix design of concrete, has an effect on both of compressive strength at each age and absorption rate. The pozzolith is more effective than vinsol resin, relating to improvement for physical proreties of concrete. 3. The use of vinsol resin as an admixture in mix design of concrete, has also an effect on both of compressive strength at each age and absorption rate. As the above fact, effectiveness of the vinsol resin is some what lower than pozzolith, as far as physical properties of the concrete are concerned. 4. Plain concrete used pozzolan cement only is the most effective on both of strength at each age and absorption rate in this study. The pozzolan cement is characteristic of higher strenth as the age is later. 5. Relationship between compreessive strengths and absorption rates of the concrete is shown by a different regression line dependingon ages. The gradient of the regression line is steeper as the age is later. 6. Throught physical test, it may be expected that the use of pozzolith and vinsol resinas asan admixture respectively will be better resistant than fly ash or ordinary plain concrete and that plain pozzolan concrete will also be the best resistant to action of sea water due to improvement of theirphysical properties.

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Properties of Baechu Kimchi treated with Black Rice Water Extract (흑미를 첨가하여 항산화성이 강화된 배추김치의 개발 및 품질 특성)

  • Mo, Eun-Kyoung;Kim, Seung-Mi;Yang, Sun-A;JeGal, Sung-A;Choi, Young-Sim;Ly, Sun-Yung;Sung, Chang-Keun
    • Food Science and Preservation
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    • v.17 no.1
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    • pp.50-57
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    • 2010
  • To develop a new functional kimchi with antioxidative properties, salted baechu was soaked in black rice water extract for 6 h at room temperature. The antioxidative property of the water extract was $78.75{\pm}1.18%$ that of the control (0.1% [w/v] alpha-tocopherol). The black rice gel was added to the baechu kimchi preparation. The color of baechu kimchi treated with black rice water extract changed to dark violet and/or black. Control kimchi and black rice water-treated kimchi were stored at $4^{\circ}C$ for 30 days. No significant differences were detected between the control and the black rice water-treated group in the early stages of fermentation. As fermentation time increased, pH decreased and titratable acidity increased rapidly in control kimchi. However, such marked changes were not evident in test kimchi. The hardness value of black rice water-treated kimchi was higher than that of control kimchi after the midpoint of the fermentation period. The storage life of baechu kimchi treated with black rice water extract was prolonged by up to 5 days compared with control samples, owing to a decline in lactic acid bacteria and yeast levels during the final fermentation period in black rice water-treated kimchi. The total phenolic levels and the antioxidative capacity of black rice water-treated kimchi (83%) were approximately 1.5-fold higher than in control kimchi (57%). In sensory evaluation, black rice water-treated kimchi scored higher than did control kimchi using a blind test protocol.

Clinical review of Typhoid Fever Patients (장티브스에 관한 임상적 관찰)

  • 최정신
    • Journal of Korean Academy of Nursing
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    • v.6 no.1
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    • pp.60-71
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    • 1976
  • The author reviewed the medical records of 96 typhoid fever patients who were diagnosed, admitted, and treated at Sea grave Memorial Hospital from January 1 , 1973 through August 31, 1975. Diagnosis was determined by clinical observation, aerology and bacteriology, eighty patients were treated medically, the remaining 16 patients required surgical intervention. The following results were obtained: 1) The age distribution of the patients revealed that 33.3% wert between 10 and 19 years old 21.9% were between 20 and 29, and 19.8% were between 30 and 39. The majority of patients were from these more active age groups. Male to female sex ratio was 1.3 : 1 2) Seasonal distribution was observed. Most illness occurred in the summer and autumn month 5. 3) 84. 3%of the patients came from farm families. 4) Duration between onset and admission averaged 16.0 days. The group without compilations was admitted after an average of 15. 1 days; The group with complications was ad-matted after an average of 19.4 days. 5) Methods of treatment before admission were as follows: 10.4% at medical clinics, 61, 5% at pharmacies (antibiotics 47.9%, other. drugs 13.5%), 7.3% by herb medications, 20.8% had no treatment. 6) Main clinical symptoms were as follows: fever 93.8%, headache 47.9%, abdominal pain 47.9%, chills 38.5%, cough 36.5%, general weakness 26.0%, nausea e vomiting 24.0% and generalized pain 21.9%. 7) Temperature of patients on admission: 22.9% were 39f or more, 67.6% were between 37℃ and 38℃, and 9.4% were 37℃ or less. 8) Occurrence of intensional bleeding after onset of disease averaged 9.3 days; perforation occurred at an average of 19. 1 days. 9) Interval between onset of major complication and surgical intervention averaged 2.8 days. 10) Among the 68 patients who underwent the bacteriological test the positive rate was 44.1% (30). The positive ,ales to, each separate culture method were as follows: 20.4% in the blood culture, 40.4% in the stool culture and 6.7% in the urine culture. Among these bacteriological positive patients 15 patients had a negative results or less than 160 titer of vidal reaction. 11) The initial vidal test of the total group showed a counts of 160 titer or more in 60.4% and less than 160 titer in 39.6%, 12) W. B. C. Counts in the uncomplicated group indicated that 32.5% were 6,000/㎣ or less, 47.5% were between 6,000 and 10,000, arid 20.0% were 10,000/㎣ or more. In the complicated group, 37.6% were 6,000/㎣ or less, 25,0% were 6,000-10,000/㎣ and 37.6% were 10,000/㎣ or more. 13) Duration of hospital stay of the patients averaged 6.4 days in the uncomplicated group and 12.7 days in the complicated group. 14) Subdiaphragmatic free air simple X-ray was found in 91.7% of the perforated cases. 15) Duration of antibiotic therapy until an febrile state was attained averaged 4.8 days in the uncomplicated group and 6.5 days in the complicated group. 16) Operative procedures were as follows: one layer simple closure of their perforation with or without debasement in 56.3%, drainage only in 6.3%, small bowel resection with primary anastomosis in 18.8% , externalization in 6.3%, cholecystectomy in 6.3%, The clinical findings of this study suggest the following recommendations. According to Top's report; 1% of typhoid fever patients treated with chlorarnphenicol and 2% of patients treated with other drugs become chronic carriers. Therefore, importance should be given to the strict control of these carriers. Immunization, improvement of sanitation and living standards are all needed for the prevention and treatment of disease, but a more serious problem is a lack of knowledge on the part of patients and their families. Thus it is most urgent to enlighten the citizens about the transmission and hygiene related to contagious disease. Legal restriction of sale of antibiotics at drug stores without a physician's prescription is an urgent matter for public health administrators. An even more important nursing responsibility is the reemphasis on health education both in the clinical setting and in the home.

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Phylogentic Position, Pigment Content and Optimal Growth Condition of the Unicellular Hydrogen-Producing Cyanobacterial Strains from Korean Coasts (한국 연안산 단세포성 수소생산 남세균 종주들의 분류계통, 색소함량 및 최적성장 환경)

  • PARK, JONG-WOO;KIM, JU HEE;CHO, AE-RA;JUNG, YUN-DUK;KIM, PYOUNG JOONG;KIM, HYUNG-SEOP;YIH, WONHO
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.20 no.3
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    • pp.131-140
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    • 2015
  • To set up unicellular cyanobacterial strains with photo-biological $H_2$ production potential, live samples were repeatedly collected from 68 stations in the coastal zone of Korea for the four years since 2005. Among 77 cyanobacterial strains established six (KNU strains, CB-MAL002, 026, 031, 054, 055 and 058) were finally chosen as the excellent strains for $H_2$ production with $H_2$ accumulation over 0.15 mL $H_2\;mL^{-1}$ under general basic $H_2$ production conditions as well as positive $H_2$ production for more than 60 hr. To explore optimum procedures for higher $H_2$ production efficiency of the six cyanobacterial strains, the inter-strain differences in the growth rate under the gradients of water temperature and salinity were investigated. The maximum daily growth rates of the six strains ranged from 1.78 to 2.08, and all of them exhibited $N_2-fixation$ ability. Based on the similarity of the 16S rRNA sequences, all the test strains were quite close to Cyanothece sp. ATCC51142 (99%). The six strains, however, were grouped into separate clades from strain ATCC51142 in the molecular phylogeny diagram. Chlorophyll- a content was 3.4~7.8% of the total dried weight, and the phycoerythrin and phycocyanin contents were half of those in the Atlantic strain, Synechococcus sp. Miami BG03511. The growth of the six strains was significantly suppressed at temperatures above the optimal range, $30{\sim}35^{\circ}C$, to be nearly stopped at $40^{\circ}C$. The growth was not inhibited by high salinities of 30 psu salinity in all the strains while strain CB055 maintained its high growth rate at low salinities down to 15 psu. The euryhaline strains like CB055 might support massive biotechnological cultivation systems using natural basal seawater in temperate latitudes. base seawater. The biological and ecophysiological characteristics of the test strains may contribute to designing the optimal procedures for photo-biological $H_2$ production by unicellular cyanobacteria.

Effect of pore-water salinity on freezing rate in application of rapid artificial ground freezing to deep subsea tunnel: concentration of laboratory freezing chamber test (고수압 해저터널에 급속 인공동결공법 적용시 간극수의 염분 농도가 동결속도에 미치는 영향 평가: 실내 동결챔버시험 위주로)

  • Oh, Mintaek;Lee, Dongseop;Son, Young-Jin;Lee, In-Mo;Choi, Hangseok
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.18 no.5
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    • pp.401-412
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    • 2016
  • It is extremely difficult to apply conventional grouting methods to subsea tunnelling construction in the high water pressure condition. In such a condition, the rapid artificial freezing method can be an alternative to grouting to form a watertight zone around freezing pipes. For a proper design of the artificial freezing method, the influence of salinity on the freezing process has to be considered. However, there are few domestic tunnel construction that adopted the artificial freezing method, and influential factors on the freezing of the soil are not clearly identified. In this paper, a series of laboratory experiments were performed to identify the physical characteristics of frozen soil. Thermal conductivity of the frozen and unfrozen soil samples was measured through the thermal sensor adopting transient hot-wire method. Moreover, a lab-scale freezing chamber was devised to simulate freezing process of silica sand with consideration of the salinity of pore-water. The temperature in the silica sand sample was measured during the freezing process to evaluate the effect of pore-water salinity on the frozen rate that is one of the key parameters in designing the artificial freezing method in subsea tunnelling. In case of unfrozen soil, the soil samples saturated with fresh water (salinity of 0%) and brine water (salinity of 3.5%) showed a similar value of thermal conductivity. However, the frozen soil sample saturated with brine water led to the thermal conductivity notably higher than that of fresh water, which corresponds to the fact that the freezing rate of brine water was greater than that of fresh water in the freezing chamber test.

Application of SP Monitoring in the Pohang Geothermal Field (포항 지열 개발지역에서의 SP 장기 관측)

  • Lim Seong Keun;Lee Tae Jong;Song Yoonho;Song Sung-Ho;Yasukawa Kasumi;Cho Byong Wook;Song Young Soo
    • Geophysics and Geophysical Exploration
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    • v.7 no.3
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    • pp.164-173
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    • 2004
  • To delineate geothermal water movement at the Pohang geothermal development site, Self-Potential (SP) survey and monitoring were carried out during pumping tests. Before drilling, background SP data have been gathered to figure out overall potential distribution of the site. The pumping test was performed in two separate periods: 24 hours in December 2003 and 72 hours in March 2004. SP monitoring started several days before the pumping tests with a 128-channel automatic recording system. The background SP survey showed a clear positive anomaly at the northern part of the boreholes, which may be interpreted as an up-flow Bone of the deep geothermal water due to electrokinetic potential generated by hydrothermal circulation. The first and second SP monitoring during the pumping tests performed to figure out the fluid flow in the geothermal reservoir but it was not easy to see clear variations of SP due to pumping and pumping stop. Since the area is covered by some 360 m-thick tertiary sediments with very low electrical resistivity (less than 10 ohm-m), the electrokinetic potential due to deep groundwater flow resulted in being seriously attenuated on the surface. However, when we compared the variation of SP with that of groundwater level and temperature of pumping water, we could identify some areas responsible to the pumping. Dominant SP changes are observed in the south-west part of the boreholes during both the preliminary and long-term pumping periods, where 3-D magnetotelluric survey showed low-resistivity anomaly at the depth of $600m\~1,000m$. Overall analysis suggests that there exist hydraulic connection through the southwestern part to the pumping well.

The Effect of After-school Programs on Science-related Attitude and Learning Achievement of High School Students : In the Unit of 'The Change of Weather' (방과후 학교 프로그램이 고등학교 학생들의 과학에 대한 태도와 학업성취도에 미치는 영향 : '날씨의 변화' 단원을 중심으로)

  • Keum, Kyung-Jin;Yoon, Ill-Hee
    • Journal of Science Education
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    • v.32 no.2
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    • pp.71-86
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    • 2008
  • The purpose of this study was to apply After-school programs related to sub-chapter 'The Change of Weather', and thereby to investigate the effect of After-school program on science-related attitude and learning achievement of students, and interaction between treatment methods and students' learning ability. The subjects of study consisted of 2nd grade students of sixty four students in high school. Sixty four students were divided into two categories by experimental and control groups on the basis of midterm examination before teaching treatment. The experimental groups have received four After-school programs including making models of a weather front, measurement of wind, measurement of temperature and the dew point, making a three-dimensional weather chart which were developed by researcher for six times. The control groups have received the instruction through the conventional teaching methods. Seventy questions within seven frameworks of TOSRA have been used in this study as an evaluation instrument of science-related attitude. Learning achievement has been evaluated using an instrument developed by researcher. The scores of both pre-test and post-test were estimated by ANCOVA. The results of this study can be summarized as follows. (1) After-school programs were more effective in progressing the three categories of science related attitude of high school students i.e. pleasure of science class(p<.05), reception of scientific attitude(p<.01), attitude about a science research(p<.05) than conventional teaching methods. (2) Experimental groups showed statistically significant improvement on learning achievement than control groups(p<.05). (3) The effect of treatment methods on students' learning ability has been improved in experimental groups more positively than control groups(p<.05). High level students in experimental groups showed significant improvement on learning achievement than low level students according to the representing profile plot. But there were no significant interaction between treatment methods and students' learning ability(p>.05) In conclusion, the After-school programs have positive effect on the improvement of science related attitude and learning achievement.

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Study of Serious Bacterial Infections in Febrile Infants Younger than Three Months of Age (열이 있는 3개월 이하의 영아에서 세균성 감염의 예측에 대한 연구)

  • Jeon, Myeoung Won;Lee, Ji Young;Jang, Young Taek
    • Pediatric Infection and Vaccine
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    • v.10 no.2
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    • pp.215-222
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    • 2003
  • Purpose : This study was to analyze serious bacterial infections in infants younger than three months of age and to review the direction of treatments for these patients. Methods : 378 febrile infants with a rectal temperature ${\geq}38.0^{\circ}C$ visited from Jan. 2001 through Dec. 2002 were retrospectively studied. Infants with the following criteria belonged to the low risk group. WBC $5,000{\sim}15,000/mm^3$, WBC negative in urine stick test and negative for nitirite test, CSF WBC < $10/mm^3$ and negative in CSF gram stain, negative chest X-ray, stool WBC <5/HFP(high power field), and focal infection. If any of the above criteria were not met, they belonged to the high risk group. SBI was defined as a positive culture of urine, blood or CSF. SI was defined as aseptic meningitis or pneumonia including above laboratory tests of SBI. SBI patients were separately compared with two groups, high risk and low risk. Results : Of the 378 infants that were tested 216(57.1%) were in the high risk group and 162(42.9%) in the low risk group. Among 105 SBI(27.8%) and 172 SI(45.5%), there were 98 urinary tract infection(25.2%), 10 bacteremia(2.6%), 2 bacterial meningitis(0.6%), and 77 aseptic meningitis(22.8%). There were 76 SBI(35.2%) from the high risk group and 29 SBI(17.9%) from the low risk group identified. The results of the sensitivity(72.4%), the specificity(48.7%), the negative predictive value(82.1%) and the positive predictive value (35.2%) were calculated. Conclusion : Even though the probability of SBI in the low risk group is insignificant, it should still be considered in febrile infants younger than 3 months of age. I believe the CSF study is necessary because of the moderate high incidence of abnormal finding in our study.

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