• Title/Summary/Keyword: Optimum water temperatures

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Effect of Temperature and Various Pre-treatments on Germination of Hippophae rhamnoides Seeds (갈매보리수나무 종자의 온도 및 여러 가지 전처리에 따른 발아반응)

  • Choi, Chung-Ho
    • Korean Journal of Plant Resources
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    • v.25 no.1
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    • pp.132-141
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    • 2012
  • This study was carried out to test seed germination responses to temperatures and pre-treatments in Hippophae rhamnoides, which has many abilities in antioxidant activity, soil improvement and erosion control. H. rhamnoides seeds were placed at 10, 15, 20, 25, 30 and $35^{\circ}C$ under light condition. As the results, germination percentage (GP) was the highest at 15 and $20^{\circ}C$, and mean germination time (MGT), germination rate (GR) and germination value (GV) were the highest at $25^{\circ}C$. Quadratic and linear regression model were used to determine the cardinal temperatures such as base ($T_b$), maximum ($T_m$) and optimum ($T_o$) temperature for germination. In quadratic regression model using PG, $T_b$, $T_m$ and $T_o$ was estimated as 0.6, 36.4 and $18.5^{\circ}C$, respectively, and temperature range for germination was $35.8^{\circ}C$. In linear regression model using GR, $T_b$, $T_m$ and $T_o$ was estimated as 8.3, 35.4 and $25.3^{\circ}C$, respectively, and temperature range for germination was $27.2^{\circ}C$. Germination properties were investigated after H. rhamnoides seeds were treated by prechilling (1, 2, 4, 6 and 8 weeks), stratification (2, 4, 6 and 8 weeks), solid matrix priming (seed : carrier : water = 5 : 1 : 7, 8, 9 and 10), osmo-priming (-0.25, -0.5, -1.0 and -1.5 MPa) and calcium chloride ($CaCl_2$) -priming (100, 200, 300 and 400 mM). The highest GP was observed in $CaCl_2$ 300 and 400 mM treatments, and MGT was the shortest in stratification 6 and 8 weeks treatments. GR and GV were the highest and GP was the second highest when seeds were prechilled for 1 and 2 weeks. Consequently, prechilling 1 or 2 weeks treatment was considered as the appropriate method when we contemplate qualitative and quantitative effects in seedling production.

Studies on the Seedling Production of the Freshwater Crab, Eriocheir japonicus (De Haan) 4. Combined Effects of Temperature-Salinity on the Moulting Intervals of Larvae (동남참게, Eriocheir japonicus (De Haan)의 종묘생산에 관한 생물학적 기초연구 4. 성장단계별 유생에 대한 脫皮 간격일수에 미치는 수온-염도의 복합적인 영향에 관하여)

  • KWON Chin-Soo;LEE Bok-Kyu
    • Journal of Aquaculture
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    • v.7 no.1
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    • pp.21-39
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    • 1994
  • In order to study the optimum environmental condition for larvae culture of the freshwater crab, Eriocheir japonicus, larvae from different growth stages and young crab were cultured under the 16 different conditions of $4\times4$ temperature-salinity combinations (4 different temperatures at 22, 24, 26, $28^{\circ}C$ with 10.5, 17.5, 24.5 and $31.5\%$ of salinity). The duration of metamorphosis, metamorphosis rate, the interval of moulting period, and survival rate were measured from each experimental group of larvae and young crab under the different conditions. The results indicated that the optimum conditions may be a $24.5\%o$ of salinity at water temperature at 22, 24, and $26^{\circ}C$. At $28^{\circ}C$ with $24.5\%o$), the duration of metamorphosis reduced somewhat, nevertheless metamorphosis and survival rate decreased a lot. And the lower the salinity showed the lower the metamorphosis and survival rates at $28^{\circ}C$.

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Studies on Seed Germination Characteristics of Rice Cultivar ‘Danmi’ and Its Optimum Seeding Rates for Seedling Raising in Machine Transplanting (단미벼의 발아 특성 및 기계이앙 육묘시 적정 파종량)

  • Kim, Sang-Yeol;Oh, Seong-Hwan;Lee, Jong-Hee;Jeong, Kuk-Hyun;Cho, Jun-Hyeon;Lee, Ji-Yoon;Park, Sung-Tae;Song, You-Chun;Yeo, Un-Sang;Kim, Jeong-Il;Seo, Woo-Duck;Kang, Hang-Won
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.55 no.2
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    • pp.126-132
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    • 2010
  • A high sugar rice cultivar 'Danmi' which has been recently developed and released in the Functional Crop Resource Development Division, Department of Functional Crop, National Institute of Crop Science, has high glucose and sucrose contents but has a poor seed development. This defect poses some problem in ensuring stable seedling establishment in the nursery bed. We examined the germination and seedling emergence characteristics of 'Danmi' and determined an optimum seeding rate for seedling establishment. 'Danmi' seeds has a light 1,000-grain weight of 18.2g compared with Ilmibyeo's 26.7g. The 97.4% of 'Danmi' seeds has specific gravity below 1.0 while only 2.0% of seeds was fully developed with specific gravity above 1.12. However, the reverse is true in the Ilmibyeo seed used as a control cultivar. Although the seed germination of Danmi was 89-91% regardless of seed specific gravity but at a slower rate than Ilmibyeo regardless of water soaking temperatures of $20-30^{\circ}C$ because of high seed amount of specific gravity below 1.0 in 'Danmi'. It took 2~4 days longer of seed soaking in the Danmi seeds than Ilmibyeo before germination. 'Danmi' has low normal seedling emergence rate than Ilmibyeo in the seedbed soil due to high percentage of abnormal seedlings like stunting and incomplete growth. Normal seedling emergence rate of 'Danmi' in the seedbed was 62.6~64.9% for 10-day old seedling and 83.5~86.7% for 30-day old seedling which is lower by 29.6~30.0% and 11.3~12%, respectively than Ilmibyeo. Although 'Danmi' has low normal seedling emergence rate, but it has greater seed number per weight basis. Therefore, based on the normal seedling number per unit area of Ilmibyeo(control cultivar) for seedling rate of 10-day and 30-day old seedlings, the recommended seeding rate of 'Danmi' for transplanting rice is 220g seeds for 10-day old seedling and 130g for 30-day old seedling per nursery box, which is equivalent to 1.5 times seed volumes of Ilmibyeo.

Improvement of Heat Pump Heating Performance by Selective Heat Storage Using Air Heat of Inside and Outside Greenhouse (온실 내외부 공기열의 선택적 축열에 의한 히트펌프 난방성능 개선)

  • Kwon, Jin Kyung;Kim, Seung Hee;Jeon, Jong Gil;Kang, Youn Koo;Jang, Kab Yeol
    • Journal of Bio-Environment Control
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    • v.26 no.4
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    • pp.353-360
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    • 2017
  • In this study, the design and performance test of the air to water heat pump capable of producing hot water for greenhouse heating by using the surplus solar heat inside the greenhouse and the air heat outside greenhouse as the selective heat source were conducted. The heat storage operations using the surplus solar heat and the outside air heat were designed to be switched according to the setting temperature of the greenhouse in consideration of the optimum temperature range of the crop. In the developed system, it was possible to automatically control the switching of heat storage operation, heating and ventilation by setting 12 reference temperatures on the control panel. In the selective heat storage operation with the surplus solar heat and outside air heat, the temperature of thermal storage tank was controlled variably from $35^{\circ}C$ to $52^{\circ}C$ according to the heat storage rate and heating load. The heat storage operation times using the surplus solar heat and outside air heat were 23.1% and 30.7% of the experimental time respectively and the heat pump pause time was 46.2%. COP(coefficient of performance) of the heat pump of the heat storage operation using the surplus solar heat and outside air heat were 3.83 and 2.77 respectively and was 3.24 for whole selective heat storage operation. For the comparative experiment, the heat storage operation using the outside air heat only was performed under the condition that the temperature of the thermal storage tank was controlled constantly from 50 to $52^{\circ}C$, and COP was analyzed to be 2.33. As a result, it was confirmed that the COP of the heat storage operation using the surplus solar heat and outside air heat as selective heat source and the variable temperature control of the thermal storage tank was 39% higher than that of the general heat storage operation using the outside air heat only and the constant temperature control of the thermal storage tank.

Studies on the Propagation of the Freshwater Prawn, Macrobrachium nipponense (De Haan) Reared in the Laboratory (담수산 징거미새우, Macrobrachium nipponense (De Haan)의 증${\cdot}$양식에 관한 생물학적 기초연구 1. 생식생태에 관한 연구)

  • Kwon Chin-Soo;Lee Bok-Kyu
    • Journal of Aquaculture
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    • v.4 no.1
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    • pp.31-66
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    • 1991
  • This paper deals with the reproductive ecology e.g., number of the pre-spawning moults, morphological characteristics of the pre-spawning moult the common moult, daily ration druing a molting cycle mating behavior, structures of spermatozoa and spermatophore, structure of vas deferens, mechanisms of the oviposition and brooding into the egg-chambers, a suitable time for the artificial mating and fertilization, time sequence of the oviposition and brooding into egg-chambers from the copulation, responses to temperature and chlorinity on the egg development and hatching, effect of temperatures on duration of egg development, physical mechanism of the egg hatching, to make an attempt for the artificial spawning and brooding to establish a suitable system of the artificial seedling-production for the aquaculture. 1. Females molted commonly $8{\~}10$ times at an interval of $17{\~}18$ days at $28^{\circ}C,\;3.26\~4.35\%_{\circ}$ while the prespawning moltings were $4{\~}5$ times at an interval of $13{\~}14$ days. The suitable state for artificial copulation was within 14 hours elapsed from the prespawning moltings (most suitable state was within 8 hours). Males discharged a gelatinous spermatophore and placed it on the females sternum during copulation. Oviposition was seen $6{\~}17$ hours after copulation. External fertilization was considered to take place at oviposition. Fertilized eggs held in egg-chambers forming between pleopods were about $5000{\~}6000$ in females those sizes about 6.5 cm in body length. 2. Eggs immediately after oviposition were elliptic shape, measuring $0.58{\times}0.48$ mm up to hatching. Their sizes increased with egg development and finally reached $0.85{\times}0.54$ mm up to hatching. The relationship between the long axis of the egg(Y in U) and days elapsed(X) was expressed as Y= 5.60194 + 0.007358X. The eggs performed superficial cleavage and their cleavage furrows became visible at the 4-daughter-nucleus stage. The eggs showed normal development up to hatching at water temperature range of $22{\~}30^{\circ}C$ (optimum temperature : $26{\~}28^{\circ}C$) and at chlorinity range of $0.00\~6.64\%_{\circ}$ (optimun chlorinity : $2.21{\%}_{\circ}$). The relationship between incubation period (Y in days) and water temperature(X in $^{\circ}C$) could be expressed as Y= 50.803-1.3555X. The eggs hatched $12{\~}13$ days after oviposition at $28.0{\~}28.6^{\circ}C$ 3. The pre-spawning moltings were appreciably different in the morphologic structure from those of common moltings. Breeding setae and dresses were formed on the thoracic regions, abdominal epimerae and the bases of the first to fourth pleopods in order to prepare and support oviposition, transfering and supporting eggs in egg-chambers up to hatching. These supplementary breeding organs were observed only at reproductive seasons.

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Determine the effects of drying temperature on the quality change and antioxidant activity characteristics of blueberry (건조 온도에 따른 블루베리의 품질변화 및 항산화특성)

  • Shin, Dong-Sun;Yoo, Yeon-Mi;Kim, Ha-Yun;Han, Gwi-Jung
    • Food Science and Preservation
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    • v.22 no.4
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    • pp.505-511
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    • 2015
  • This study was performed to investigate the effect of drying temperature on the quality characteristics and antioxidant activity of blueberry. Blueberries were dried at different times and temperatures, including A ($40^{\circ}C$, 72 hr), B ($40^{\circ}C$, 48 h and $50^{\circ}C$, 24 hr), C ($50^{\circ}C$, 72 hr), and D ($60^{\circ}C$, 72 hr). The yield and pH ranges of blueberry were determined to be 17.73~31.17% and 3.20~3.25, respectively. The yield rate of A treatments, soluble solid of D treatments, was the highest. The yield rate and soluble content was the highest in the treatment of A and D, respectively. The moisture content and water activity were significantly decreased with the increase in drying temperature (p<0.05). The L value of A treatment, and a and b values of D treatment were the greatest. In the analysis of texture analyzer, hardness, springiness, cohesiveness, gummiess and chewiness were significantly increased with the increase in drying temperature (p<0.05). In the sensory evaluation of blueberry, the appearance and color were the highest in the A treatment. The moisture, texture and taste was highest in the B treatment. The overall acceptability was in the order of B > A > C >D. The total polyphenol content and DPPH radical-scavenging activity were 9.21~13.05 mg/GAEg and 61.90~81.42%, respectively, which were significantly decreased with the increase in drying temperature (p<0.05). Therefore, the optimum time and temperature for blueberry drying was founded to be B treatment ($40^{\circ}C$, 48 hr and $50^{\circ}C$, 24 hr) among other treatments.

Mass-rearing Method of the Fungus Gnat, Bradysia difformis (Sciaridae, Diptera) in Laboratory (실내에서 작은뿌리파리(Bradysia difformis, Sciaridae, Diptera)의 대량사육시스템)

  • Jang, Hyun Ju;Yoon, Heon;Kwon, Hey Ri;Yu, Yong Man;Youn, Young Nam
    • Korean journal of applied entomology
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    • v.57 no.2
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    • pp.57-64
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    • 2018
  • The fungus gnat, Bradysia difformis, has been recognized as an important pest of greenhouse crops. There is a need for research on the control of the fungus gnat. However, it is difficult to obtain many generations of the fungus gnat for several kinds of research. Indoor propagation is a very useful method for obtaining enough individuals in cases where the need is for larvae in soil. This study was conducted to determine the optimum growing media and temperature conditions for rearing the fungus gnat in the laboratory. Under experimental temperature conditions, hatching, pupation, and eclosion rates were the highest at $20^{\circ}C$. The developmental period of the fungus gnat was shortened with higher temperatures. The greatest number of eggs was an average of 144 at $20^{\circ}C$. Using different types of larvae growth media, the highest hatching rates were 84.7 and 84.4% in water agar and potato disks, respectively. The larval period was the shortest, at 14.7 days, when grown on potato disks. The highest pupation and eclosion rates were 85.2 and 82.6% on potato disks, respectively. The highest number of eggs was an average of 125.6 on potato disks. Regarding the effects of different growth media on the eclosion rate of B. difformis, the highest eclosion rate was 88.4% on the soil mix, and was 50% on oatmeal, 25% on shredded potato. The results of four different inoculation levels of larvae on eclosion rate of B. difformis showed that the highest eclosion rate was 84.7% for 1,000 larvae. The eclosion rate was shortened with a higher number of larvae inoculated/cage. In the growth medium used, 3,000 eggs were better for the initial level of inoculation, showing a relatively high emergence rate and short developmental period. Mass rearing procedures were explained in detail.

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.

Changes in Quality of Rehmanniae radix Preparata with Heating Conditions (열처리조건에 따른 숙지황의 품질변화)

  • Song, Dae-Shik;Woo, Koan-Sik;Seong, Nak-Sull;Kim, Kwang-Yup;Jeong, Heon-Sang;Lee, Hee-Bong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.6
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    • pp.773-778
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    • 2007
  • This study was performed to develop a more simple and convenient heat treatment process for increasing heating temperature than the traditional 9-times steaming process for Rehmanniae radix Preparata (R. radix P.). The R. radix was heated to various temperatures (110, 120, 130, 140 and $150^{\circ}C$) for different lengths of time (1, 2, 3, 4 and 5 hr). Chromaticity, free sugar, amino acid, catalpol and 5-HMF (5-hydroxy-methyl-2-furaldehyde) content of water extracts of R. radix P. were analysed. With increasing heating temperature and time, the L, a and b-value of samples gradually decreased. Fructose and glucose contents were increased to $120^{\circ}C$ for 5 hr (5.21 and 6.67%, respectively) with no changes afterward. Sucrose content was not detected after $130^{\circ}C$. Total amino acid was increased to $140^{\circ}C$ and decreased afterward. The maximum total amino acid content was 4,172 mg/100 g at $140^{\circ}C$ for 2 hr (R. radix L.: 3,029 mg/100 g). The catalpol was decreased to $130^{\circ}C$ for 1 hr and not detected afterward. The 5-HMF content increased with increasing heating temperature and time. The maximum content of 5.HMF was 2.5% in $150^{\circ}C$ for 5 hr. Hence, it can be suggested that the heat treatment at $130^{\circ}C$ for 2 hr or more is the most optimum processing conditions, instead of the traditional 9.times steaming process.

Studies on Reaction Parameters for Composting of Paper Mill Sludge in a Small-Scale Reactor and Static Piles (제지슬럿지의 퇴비화를 위한 반응변수 연구)

  • Han, Shin Ho;Chung, Young Ryun;Cho, Cheon Hee;Kang, Moon Hee;Oh, Say Kyun
    • Journal of the Korea Organic Resources Recycling Association
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    • v.2 no.2
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    • pp.19-29
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    • 1994
  • A large volume of paper mill sludge(PMS) is produced every day from paper industries after treatments of waste water and it costs too much to dispose of the sludge. Since PMS consists mostly of biodegradable organic matter, cellulose, it is desirable to recycle it by proper treatments such as composting. In this study, experiments were conducted using a small scale reactor(12l) to establish optimum conditions for efficient composting of PMS of which initial pH, C/N ratio, and moisture content were 7.1, 28~30, and 60~65%, respectively. No heavy metals such as mercury, cadmimum, and lead were not detected in the PMS. Various levels of forced aeration, 1 minute aeration per every 30, 60, 120, 240, and 480 minutes were applied and 1 minute aeration per 60 and 120 minutes found to be proper for composting of 8l PMS in this system. Relationship between $CO_2$ production and temperatures was positively correlated with r> 0.82 suggesting that the normal decomposition of PMS by microorganisms occurred. However, under the condition of aeration interval over than 240 minutes, a negative relationship between two parameters was found indicating the occurrence of abnormal(maybe anaerobic) degradation. The amount of added nitrogen also affected composting of PMS resulting in the increase of $CO_2$ production and temperature. Semi-field tests using 100kg PMS in a static pile sysem showed that PMS could be composted efficiently under optimal environmental conditions. The parameters determining efficiency of composting such as C/N ratio, aeration, moisture content, and pH need to be monitored.

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