• Title/Summary/Keyword: Low-temperature

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Characterization of a new commercial strain 'Goni' by intra-specific hyphal anastomosis in Pleurotus ostreatus (계통간 교잡에 의한 백색느타리 품종 '고니'의 육성 및 그 특성)

  • Yoo, Young Bok;Lee, Sang Cheol;Kim, Eun Jung;Kong, Won Sik;Jang, Kab Yeul;Shin, Pyung Gyun
    • Journal of Mushroom
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    • v.7 no.3
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    • pp.130-134
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    • 2009
  • To develop new white variety of Oyster mushroom, all white varieties which have been collected and kept in the lab were revived and screened their cultural characteristics. 84 intra-specific Oyster mushroom hybrids between the white-colored mutants Suhan and Wonhyeong were developed using hyphal anastomosis technique in 2007. The Po2007-63 ($2842-7{\times}0205-7$) was shown the best cultural characteristics, selected to be a new variety and named as 'Goni'. The new commercial strain, 'Goni' has white pilei and grows well under spring and autumn conditions in Korea. The fruiting bodies of 'Goni' are of an excellent quality in that not only the stipe is thick and long but also the pileus is small and hard. The optimum temperatures for mycelial growth and fruiting body development were $25-30^{\circ}C$ and $10-16^{\circ}C$, respectively. Time period required for the initiation of the first fruiting body is about 3 to 5 days depending on the temperatures. The shape of fruiting body is thin funnel shape. Fruiting body production per bottle was about $91{\pm}13$ g which is almost 97% quantity compared to that of other variety 'Miso'. Relatively low temperature incubation ($11^{\circ}C$) resulted in the development of better quality of 'Goni' mushrooms. When two different media including potato dextrose medium and mushroom complete medium were compared, the growth of mushroom were much faster in mushroom complete medium at $20-25^{\circ}C$, but not at $25^{\circ}C$. Similar results were observed with other variety 'Miso'. Analysis of the genetic characteristics of the new commercial strain 'Goni' showed a major DNA profile as that of the parental Suhan when primer URP 1 was used, but different to 'Miso' that was used as a control. When screens were performed with primer URP 2, DNA patterns were similar both to that of the parents and 'Miso'. This new variety of the white Oyster mushroom has a clean and fresh image that corresponds well to "health food". We therefore expect that this new strain will satisfy the consumers demand for variety and excellent mushrooms.

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Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2013 (설비공학 분야의 최근 연구 동향 : 2013년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.26 no.12
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    • pp.605-619
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    • 2014
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2013. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and relative parts including orifices, dampers and ducts, fuel cells and power plants, cooling and air-conditioning, heat and mass transfer, two phase flow, and the flow around buildings and structures. Research issues dealing with home appliances, flows around buildings, nuclear power plant, and manufacturing processes are newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for general analytical model for desiccant wheels, the effects of water absorption on the thermal conductivity of insulation materials, thermal properties of Octadecane/xGnP shape-stabilized phase change materials and $CO_2$ and $CO_2$-Hydrate mixture, effect of ground source heat pump system, the heat flux meter location for the performance test of a refrigerator vacuum insulation panel, a parallel flow evaporator for a heat pump dryer, the condensation risk assessment of vacuum multi-layer glass and triple glass, optimization of a forced convection type PCM refrigeration module, surface temperature sensor using fluorescent nanoporous thin film. In the area of pool boiling and condensing heat transfer, researches on ammonia inside horizontal smooth small tube, R1234yf on various enhanced surfaces, HFC32/HFC152a on a plain surface, spray cooling up to critical heat flux on a low-fin enhanced surface were actively carried out. In the area of industrial heat exchangers, researches on a fin tube type adsorber, the mass-transfer kinetics of a fin-tube-type adsorption bed, fin-and-tube heat exchangers having sine wave fins and oval tubes, louvered fin heat exchanger were performed. (3) In the field of refrigeration, studies are categorized into three groups namely refrigeration cycle, refrigerant and modeling and control. In the category of refrigeration cycle, studies were focused on the enhancement or optimization of experimental or commercial systems including a R410a VRF(Various Refrigerant Flow) heat pump, a R134a 2-stage screw heat pump and a R134a double-heat source automotive air-conditioner system. In the category of refrigerant, studies were carried out for the application of alternative refrigerants or refrigeration technologies including $CO_2$ water heaters, a R1234yf automotive air-conditioner, a R436b water cooler and a thermoelectric refrigerator. In the category of modeling and control, theoretical and experimental studies were carried out to predict the performance of various thermal and control systems including the long-term energy analysis of a geo-thermal heat pump system coupled to cast-in-place energy piles, the dynamic simulation of a water heater-coupled hybrid heat pump and the numerical simulation of an integral optimum regulating controller for a system heat pump. (4) In building mechanical system research fields, twenty one studies were conducted to achieve effective design of the mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, and renewable energies in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment is mostly focused on indoor environment and building energy. The main researches of indoor environment are related to infiltration, ventilation, leak flow and airtightness performance in residential building. The subjects of building energy are worked on energy saving, operation method and optimum operation of building energy systems. The remained studies are related to the special facility such as cleanroom, internet data center and biosafety laboratory. water supply and drain system, defining standard input variables of BIM (Building Information Modeling) for facility management system, estimating capability and providing operation guidelines of subway station as shelter for refuge and evaluation of pollutant emissions from furniture-like products.

Performance Status of Sanitary Management of School Food Service in the Jeonnam Area (전남지역 학교급식의 위생관리 실태)

  • 고무석;정난희;이전옥
    • Korean Journal of Human Ecology
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    • v.7 no.1
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    • pp.51-67
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    • 2004
  • This study analyzed the effects of nutrition technicians' hygiene education on cooking workers' performance of hygiene management in order to ensure the security of school meals. The situation of cooking workers' disposition in subject schools was elementary school(51.1%) and middle school(48.9%) and the type of meals was rural area type(54.2%), urban type(36.5%). and island and isolated area type(9.3%). The methods of meals management were single cooking(88.2%) and joint cooking and management(11.8%). The type of distributing meals was distributing in a dining room(93.5%), in a classroom(3.7%), and in both dining room and classroom(2.8%). Nutrition technicians' employment form included regular(53.5%) and daily(88.2%). Their education was junior college graduate(50.2%), university graduate(44.8%). and graduate school students(5.0%). Cooking workers' employment form included daily(88.2%) and regular (11.1%). suggesting that most were regular. Most cooking workers(77.4%) had at least high school certificate. Regarding the situation of cooking workers' disposition in subject schools, the number of student per one cooking worker was found as 91-120(37.2%), 61-90(22.6%). 60 and under(21.l %). 121-15006.7%). and 151 and over(2.5%). Cooking workers' level of performance of hygiene management was post-working stage(66.37/75 marks), pre-working stage(64.22/75 marks). and working stage(20.34/25 marks), The counting of meals articles in a pre-working stage(20.34/25 marks). temperature and required time in a working stage(18.78/25 marks), and machinery equipment and hygiene in a pre-working stage(21.40/25 marks) showed lowest of performance, which suggest poor service of hygiene. Cooking workers' performance of hygiene management by working stage showed the significant difference with school class(p<.001), type of schools with meals(p<.05). state of cooking workers' employment(p<.001), and cooking worker's disposition(p<.05). A working stage showed the significant difference with type of schools with meals(p<.05). A post-working stage showed the significant difference according to type of schools with meals(p<.05), and the methods of meals management(p<.05), and cooking workers' disposition(p<.05). In the execution of hygiene education, individual hygiene was highest(94.8%), followed by the management of machinery equipment and tools(89.7%), food poisoning and microorganism(94.7%), and the method of food treatment(76.4%). A yearly plan of hygiene education included established(83.9%) and not established(l6.1%). Regular education included not executed(25.1%), 2-3 times a month(l6.1%), and more than 4 a month(4.0%) and occasional education was not executed(57.0%), 1-3 times a month(26.3%), and more than 4 a month(l5.7%). In the methods for hygiene education, oral education(95.7%) was used most, followed by demonstration(10.5%), poster/photo(10.5%), video/slide(3.7%), and computer(3.7%). Frequency of improvement and complement of hygiene education included once a month(56.3%), once a year(20.7%), by quarter(l1.5%), and every six months(1l.5%). Newspaper was used most in materials of hygiene education, followed by internet, TV, nutrition technician's reeducation, information exchange between members, educational office's training, and reference book, and educational office's material. and symposium. Cooking workers' assessment of the effect of hygiene education was conducted through observation(56.8%), check table(l5.2%), question(l4.0%), and examination(14.0%). The reason of cooking workers' low level of performance included habitual custom(53.9%), lack of understanding(20.4%), overwork(l4.6%), and lack of knowledge(l1.l%) and the reason of difficulty in hygiene education included lack of time(55.3%), lack of understanding(27.6%), lack of knowledge and information(8.7%), and lack of budget(48.0%).

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Studies on the Epidemiology and Control of Bacterial Leaf Blight of Rice in Korea (한국에 있어서의 벼흰빛잎마름병의 발생생태와 방제에 관한 연구)

  • Lee Kyung-hee
    • Korean journal of applied entomology
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    • v.14 no.3 s.24
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    • pp.111-131
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    • 1975
  • The study has been carried out to investigate the occurrence, damage, characteristics of the pathogen, environmental conditions affecting the disease outbreak, varietal resistance, forecasting, and chemical control of bacterial leaf blight of rice in Korea since 1964. Bacterial leaf blight of rice became a major disease in Korea since 1960. A correlation was found between the annual increase of epidemics and increase of cultivation area of susceptible varieties, Jinheung, Keumnampung etc. Areal damage within the country showed that the more was at southern province, Jeonnam, Gyeongnam and western coast, and at flooded rice paddy. Yield reduction directly related with the amount of infection on upper leaves at heading stage. Fifty per cent of reduction resulted when the lesion area was more than 60 per cent. Less than 20 per cent of lesion area, however, was not affected so much on yield loss One hundred and six isolates collected from all over the country were classified as 8 strains by using 4 different bacteriophages in 1973. It was, however, only two in 1965. There were some specificities on varietal distributions among the strains such as that the Jinheung attacked mainly by strain A, B, C and I, those attack Kimmaze were A, B, H and I. Most strains were found from Tongil except D and E, whereas Akibare was only variety that attacked by strain E. Low temperature, high humidity, heavy rainfall and insutficient daylight favored the disease epidemics. Especially, typhoon and flooding at heading stage were critical factors. The earlier transplanting the more disease was resulted, and more nitrogen fertilizer application accerelated the diseased development in general. The resistance to the disease varied by growing stage of the sane plants. All of recommended varieties in Korea were susceptible to the disease except Norm No. 6 and Sirogane which moderately resistant. The pathogen, Xanthomonas oryzae, was detectable from extract of healthy seedlings that were grown in the field with an heavy infection previous year. The more bacteriophage in irigation water resulted the more disease outbreak, and the existence of more than 50 bacteriophages in 1ml. of irrigation water were necessary to initiate the disease out break. The curves representing occurrence of bacteriophages and disease outbreak were similar with 15 days interval. The survey of bacteriophage occurrence can be utilized in forecasting of the disease two weeks ahead of disease outbreak. Three applications of chemicals, Phenazin and Sangkel, in weekly intervals at the early satage of out-break depressed the symptom development, and increased yield by 20per cent. Proper period for the chemical application was just before the number of bacteriophage reaches 50 in 1ml. of irrigation water.

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Temporal and Spatial Variations of Water Quality in the Cheonsu Bay of Yellow Sea, Korea (천수만 수질환경의 시·공간적 변동특성)

  • Park, Soung-Yun;Heo, Seung;Yu, Jun;Hwang, Un-Ki;Park, Jong-Su;Lee, Sung-Min;Kim, Chang-Mi
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.19 no.5
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    • pp.439-458
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    • 2013
  • Temporal and spatial variations of water quality were investigated in the Cheonsu Bay of Yellow Sea, Korea from 2010 to 2011. Water samples were collected at 16 stations and physicochemical parameters were analyzed including water temperature, salinity, suspended solids (SS), chemical oxygen demand (COD), dissolved oxygen (DO), Chlorophyll a and nutrients. Spatial distribution patterns of all survey items were not clear among stations but the bimonthly variations were distinct except the bottom water of the suspended solids. The trend analysis by principal component analysis (PCA) during 2 years revealed the significant variations in water quality in the study area. Spatial water qualities were discriminated into 3 clusters by PCA; station cluster in the surface water 1, 2~11, and 12~16, the bottom water 1, 2~7, and 8~16. Annual bimonthly water qualities were clearly discriminated into 3 clusters by PCA. But tend of cluster in the surface and bottom water was difference, period most of the research was low in nutrient. Ecology-based water quality criteria was a good level of grade II. Bimonthly results are shown as III grade(normal) at June and August, II grade(good) at October and December and I grade for February and April. Water quality was showed by the input of fresh water same as those of Kyoungin coastal area, Asan coastal area, Gunsan coastal and Mokpo coastal area in the Cheonsu.

Control of Diatrype stigma Occurred on the Bed-log of Shiitake Using Wood Vinegar, Plant Extracts and Fungicides (목초액, 식물추출물 및 살균제를 이용한 표고골목해균인 주홍꼬리버섯 방제)

  • Bak, Won-Chull;Lee, Bong-Hun;Ka, Kang-Hyeon;Cho, Tae-Soo;Lee, Hak-Joo;Lee, Sung-Suk;Kim, Myung-Kil;Cha, Byeong-Jin
    • The Korean Journal of Mycology
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    • v.34 no.1
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    • pp.22-28
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    • 2006
  • Attempts were made to control Diatrype stigma occurred on the bed-log of Shiitake using wood vinegar, Pinus koraiensis extract, Piper nigrum extract, and fungicides. Mycelial growth of D. stigma was inhibited completely at 35,000 ppm and no ascospore germinated at 25,000 ppm wood vinegar. Inhibition rates of Pinus koraiensis extract (200 ppm), and Piper nigrum extract (1,000 ppm) to ascospore germination were 98.9% and 95.9%, respectively. In fungicide selection, minimum inhibitory concentration (MIC) of benomyl, carbendazim, and thiabendazole ranged $0{\sim}0.4\;{\mu}g\;a.i/m{\ell}$. Difenoconazole at $0.08\;{\mu}g\;a.i/m{\ell}$ inhibited 98.9% of ascospore germination. Inhibition efficacy of fungicides was not highly variable among the low-, middle-, and high-temperature type strains of shiitake. Benomyl, carbendazim, thiabendazole and thiophanate-methyl could not suppress the mycelial growth of Shiitake. Tebuconazole at $0.4\;{\mu}g\;a.i/m{\ell}$ suppressed 80% of the mycelial growth and it was the highest inhibition rate among the fungicides. In field trials, wood vinegar, Pinus koraiensis extract, Piper nigrum extract, and fungicides were sprayed on the bed-logs before or after D. stigma produced pycnidia. Wood vinegar at 150,000 ppm concentration, showed control effect of 72.7% in the treatment before pycnidiospore formation. On the other hand, 70,000 ppm wood vinegar and 1,000 ppm of thiophanate-methyl showed control effects of 58.1% and 52.3% in the treatment after pycnidiospore formation.

Changes in Chemical Components of Freeze-Dryed Ginsengs and Red Ginseng Processed from the Fresh Ginseng Stored at Low Temperature (저온저장한 수삼의 가공 중 성분변화)

  • Chang, Jin-Kyu;Lee, Jong-Won;Shim, Ki-Hwan
    • Journal of Ginseng Research
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    • v.27 no.2
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    • pp.72-77
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    • 2003
  • The six-year old fresh ginseng collected at earlier October was stored for 10 weeks in the condition of 4$^{\circ}C$${\pm}$1$^{\circ}C$ and RH 87∼92%, and the chemical components were investigated in an interval oi one week by taking sample of it after making it to the freeze-dryed ginseng and the red ginseng. The total sugar content of the red ginseng was a little reduced as the period of storage elapsed, and the reducing sugar content was 1.48eic before it was stored and was increased to 23.33% after 10 weeks of storage. For the free sugar of the red ginseng, the content of the fructose was increased, bit the contents of the glucose and the sucrose were gradually decreased after it was a little increased. The content of the maltese was 6.62% before storage and it was gradually decreased. For the free sugar of the freeze-dryed ginseng, the contents of the fructose, the glucose and the sucrose were increased. Especially the content of the sucrose was 10.96% before it was stored and was a increased to 24.38% after 7 weeks of storage, and the content of maltose was not detected. The yield of water extract was a little high at 7-8 weeks of storage and the pH was a little high at 3-4 weeks of storage. The turbidity was not changed for the freeze-dryed ginseng but was decreased for the red ginseng The water non-soluble protein was not detected in the red ginseng, and for the freeze-dryed ginseng the water non-soluble protein was reduced and the water soluble protein was increased as the period of storage was elapsed. The contents of the phenolic compounds for the red ginseng and the freeze-dryed ginseng and have their peak values after 7 and 9 weeks of storage respectively, and the amount of phenolic compounds was larger for the red ginseng. For the content of the non-volatile organic acids, the content of the citric acid was decreased both for the red ginseng and the freeze-dryed ginseng, and the contents of the glut-matic acid and the pyruvic acid were very small for the freeze-dryed ginseng, but were detected in the red ginseng at a maximum value of 37 ${\mu}$g/g and 592 ${\mu}$g/g respectively.

Characteristics of Fatty Acid Composition and Properties by Blending of Vegetable Oils (식물성 기름의 혼합을 통한 지방산 조성 및 이화학적 특성 변화)

  • Lee, Tae Sung;Lee, Yong Hwa;Kim, Kwang Soo;Kim, Wook;Kim, Kwan Su;Jang, Young Seok;Park, Kwang Geun
    • Korean Journal of Plant Resources
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    • v.25 no.5
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    • pp.624-632
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    • 2012
  • As there have been lately many worldwide resource challenges such as potential exhaustion of fossil fuels, sudden rise of oil price and ever-rising grain pricing due to global food crisis, there have been more interests focused on recycling vegetable oils and fats into clean natural fuel and producing new resources based on waste cooking oil as a part of reusing waste resources. An Experiment was performed by using ratio of 50:50, 75:25 (w/w) mixture of based rapeseed oil, camellia oil, and olive oil. 50:50, 25:75 (w/w) mixture of based palm oil. The result was that the oleic acid ($C_{18:1}$) got the lowest percentage of 42.8%, when we combined the mixture of rapeseed oil and soybean oil. While the highest percentage of 72.1% was when the mixture of camellia oil and rapeseed oil were combined at 50:50 ratio. In 75:25 (w/w) case, mixture of rapeseed oil and soybean oil got the lowest. The highest ratio was the mixture of camellia oil and olive oil. Based on the component of palm oil, the total saturated fatty acid was decreased. It is expected that stabilizing oxidation through controlling of fatty acid after mixture and that liquidity at a low temperature. The acid value indicated that stabilizing oxidation got a range of highest to lowest. Camellia oil ranked as the highest, followed by olive oil, and the oil seeds as the lowest in rank. Controlling iodine value through mixture and improvement of stabilizing oxidation will provide a good quality. The quality of color has no significant change about mixture in ratio and maintenance. The reduction of the cost of refining process is expected by controling of mixture ratio at biodiesel production in the future.

Adventitious Shoot and Plant Regeneration from Anther Culture of Hypericum ascyron L. (물레나물 약배양에 의한 부정 신초 및 식물체 재분화)

  • Ko, Jeong-Ae;Kim, Hyun-Soon;Kim, Hyung-Moo
    • Korean Journal of Plant Resources
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    • v.21 no.5
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    • pp.368-373
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    • 2008
  • In order to investigate the effects of low temperature pretreatment of floral bud and plant growth regulators on anther-derived callus and shoot differentiation, anthers were cultured on 1/2 MS medium supplemented with 2,4-D, NAA, BA and TDZ. This plant depends on the plant growth regulators, for these anthers couldn't respond on 1/2 MS medium without plant growth regulators. 2,4-D was a prerequisite substance in this experiment, especially 52.6% of callus formation on MS medium with 2.0mg/L 2,4-D alone. However, the optimum medium was on 1/2 MS medium with 0.1 mg/L 2,4-D and 1.0mg/L BA for continuous growth and shoot differentiation from the anther. Calli derived from on MS medium with 2.0mg/L 2,4-D transferred to the 1/2MS medium with TDZ and BA. TDZ were less superior to BA, only one anther could produce shoot on MS media with 1.0mg/L TDZ. On the other hand, when the calli transferred to the medium with 3.0mg/L BA, adventitious shoots were proliferated, subsequently, regenerated shoots elongated from the embryogenic calli. After floral buds of one week before anthesis were incubated at $5^{\circ}C$ refrigerator for eight or fifteen days, anthers seperated from floral buds were cultured on 1/2MS medium supplemented with 0.1mg/L 2,4-D and 1.0mg/L BA. Callusing and shoot differentiation on anthers from treated at $5^{\circ}C$ for eight days were more effective than those of fifteen days or control.

Extraction Characteristics of Flavonoids from Lonicera flos by Supercritical Fluid Carbon Dioxide ($SF-CO_2$) with Co-solvent (초임계유체 $CO_2$ 및 Co-solvent 첨가에 따른 금은화(Lonicera fles)의 Flavonoid류 추출특성)

  • Suh, Sang-Chul;Cho, Sung-Gill;Hong, Joo-Heon;Choi, Yong-Hee
    • Korean Journal of Food Science and Technology
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    • v.37 no.2
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    • pp.183-188
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    • 2005
  • Effects of co-solvent polarity, citric acid, pressure, temperature, run time, and co-solvent ratio on extraction of major flavonoids from Lonicera Flos were investigated using supercritical fluid $CO_{2}(SF-CO_{2})$. HPLC analysis revealed addition of pure methanol resulted in low extraction yield of major flavonoids, luteoloin (Lu), Quercetin (Qu), Apigenin (Ap). Under same condition, as co-solvent polarity increased, yields of major flavonoids increased gradually, At optimum co-solvent extraction condirion of 60% aqueous methanol (10%, v/v), yields of Lu, Qu, and Ap were 42.09, 28.18, and 3.49 mg/100 g, respectively. Addition of citric acid to 60% aqueous methanol gave higher, with addition of 1% citrie acid resulting in highest yields of 63.2 (Lu), 39.35 (Qu), and 5.79 (Ap) mg/100 g. Optimum extraction conditions of major flavonoids were 200 bar, $50^{\circ}C$, 60 min, and $CO_{2}$-methanol-water(20: 1.8: 1.2).