• Title/Summary/Keyword: Temperature control and agriculture technology

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Characteristics of Temperature Distribution of Pen for Exhaust Fan of Ventilation System (돈사용 환기팬을 위한 돈사 내 온도 분포 특성)

  • Kim, Hyeon-Tae;Kim, Woong
    • Journal of Animal Environmental Science
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    • v.20 no.4
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    • pp.155-160
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    • 2014
  • This study was researched for use by data for the improvement of ventilation system of optimum environmental control systems. The ventilation system for windowless swine housing was installed negative pressure system that circular pipe duct for inlet was installed on the ceiling and axial flow fan for exhaust was installed on the sidewall. The temperatures in the pen was measured using infrared thermography camera and thermocouple with data-logger. The temperature measurement points was selected by infrared thermography camera is alley (G), inlet (A), front-upper (B), front-lower (C), rear-upper (D), rear-lower (E), forward fan (F). The temperature measured at those selected points for temperature distribution was $28^{\circ}C$ that was maintained setting temperature in suitably. The temperature deviations of F point and A~E points in windowless swine housing was less then average $0.5^{\circ}C$. The result of air velocity of measured points was suitable to the breeding of pigs.

Effect of Silicon on Growth and Temperature Stress Tolerance of Nephrolepis exaltata 'Corditas'

  • Sivanesan, Iyyakkannu;Son, Moon Sook;Soundararajan, Prabhakaran;Jeong, Byoung Ryong
    • Horticultural Science & Technology
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    • v.32 no.2
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    • pp.142-148
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    • 2014
  • Effect of silicon (Si) nutrition on growth and temperature stress tolerance of Nephrolepis exaltata 'Corditas' grown in a soilless substrate was examined. In vitro-grown acclimatized plantlets were transplanted into the pots containing a coir-based substrate. A nutrient solution containing 0, 50, or $100mg{\cdot}L^{-1}$ Si was supplied through a drip-irrigation system. After 5 months of cultiv ation, S i-treated and -untreated p lants were grown at 10, 25, or $40{\pm}1^{\circ}C$ under a 12 h photoperiod with $530{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD and 60% RH. After 7 days, chlorophyll content and chlorophyll fluorescence parameters were measured. Silicon nutrition had a negative effect on growth characteristics of N. exaltata 'Corditas'. However, Si-treated plants had more tolerance to temperature stress than the control plants. The Fv/Fm value was not significantly different when the plants were exposed to $25^{\circ}C$. However, significant difference in Fv/Fm was recorded when plants were exposed to 10 or $40^{\circ}C$. Thus, Fv/Fm could be used as an indicator of low and high temperature tolerance in ferns. The present study also suggests that application of Si may be used to enhance temperature tolerance of ferns.

Effect on Growth and Quality of Oriental Melon (Cucumis melo L. var. makuwa Makino) by Interspace Mulching between Polyethylene Film House (하우스 동간멀칭이 참외의 생육 및 품질에 미치는 영향)

  • Shin Yong-Seub;Yeon Il-Kweon;Seo Young-Jin;Do Han-Woo;Lee Ji-Eun;Park So-Deuk;Choi Chung-Don
    • Journal of Bio-Environment Control
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    • v.15 no.2
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    • pp.184-189
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    • 2006
  • Effects of interspace mulching between polyethylene film house on growth and quality of oriental melon were followed. Soil moisture in control was 26.0%. Those of black nonwoven fabrics sheet and black film were less 1.2% and 2.9% than control, respectively. Soil temperature in control plot was $2.4^{\circ}$ Those of black nonwoven fabrics sheet and black film were higher $0.8^{\circ}$ and $1.8^{\circ}$ than control, respectively. Black film was better than control in stem length, leaf number and area, chlorophyll content, xylem exudate, first flowering and fruit riping periods. Black film was better in fruit weight and soluble solid, and lesser in fermented and malformed fruit ratios, and increased 28% in marketable fruit ratio to control, 1,864kg. This results were mainly from vinyl coverage between polyethylene film house to intercept rainfall and to increase soil temperature, which fasted growth of roots after transplanting in winter season.

Effect of Low Pressure Steam Explosion Treatment on Prevention of Resin Exudation from Wood under High Temperature Surroundings (저압증기폭쇄(低壓蒸氣爆碎)처리가 고온영역(高溫領域)하에서의 목재(木材) 수지삼출(樹脂渗出) 예방에 미치는 영향)

  • Lee, Nam-Ho;Park, Hee-Jun;Li, Chengyuan;Jin, Young-Moon
    • Journal of the Korean Wood Science and Technology
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    • v.32 no.2
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    • pp.9-18
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    • 2004
  • This study was carried out to find the efficient methods for preventing resin exudation from spruce board during high temperature environment service.In the dry-air oven test, in-use temperature related to resin exudation of 110℃ could be obtained by the appropriate kiln drying without any special treatment, and the in-use temperature of the radio-frequency/vacuum (RF/V)-dried boards was about 20℃ higher than that of the conventional kiln-dried boards.In the autoclave test, resin exudation was not found from any board dried in the conventional kiln and in the RF/V kiln after the low pressure steam explosion (SE) treating, while for the control resin exudations were more severe in the autoclave test above 130℃ than in the dry-air oven test. It, therefore, would be suggested that resin exudation during high temperature service condition can be prevented more effectively by super-heated steaming green boards than by high-temperature drying boards with low moisture.

Far Infrared Rays Drying Characteristics of Tissue Cultured Mountain Ginseng Roots (산삼배양근의 원적외선 건조특성)

  • Li, H.;Kwang, T.H.;Ning, X.F.;Cho, S.C.;Han, C.S.
    • Journal of Biosystems Engineering
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    • v.34 no.3
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    • pp.175-182
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    • 2009
  • This study was conducted to investigate the drying characteristics of tissue cultured mountain ginseng roots. The far infrared rays dryer of a double blast system used for this experiment can control the drying parameters such as far infrared heater temperature and air velocity. The far infrared rays drying tests of tissue cultured mountain ginseng roots were performed at air velocity of 0.4, 0.6, 0.8 m/s, under drying air temperature of 50, 60, and $70^{circ}C$, respectively. The results were compared with one obtained by the heated air drying method. The drying characteristics such as drying rate, color, energy consumption, saponin components and antioxidant activities were analyzed. The results showed that the drying rate of far infrared rays drying was faster than that of heated air drying and due to high temperature of drying air and fast air velocity, the far infrared rays drying of double blast type was superior to the heated air drying. The value of the color difference for heated air drying was 10.11${\sim}$12.99 and that of far infrared rays drying was in the range of 7.05${\sim}$7.54, which was in the same drying condition, also energy consumption of far infrared rays drying was in the range of 3575${\sim}$6898 kJ/kg-water. At the same time, the antioxidant activities using far infrared rays drying were higher than those using heated air drying.

Development of Dry Forming Mold for the Feasibility Study of Dry Forming of Paper (건식초지기술의 가능성 평가를 위한 건식초지기 개발)

  • Kim, Jong-Min;Youn, Hye-Jung;Lee, Hak-Lae
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.39 no.2 s.120
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    • pp.1-8
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    • 2007
  • To examine the feasibility of dry forming technology for papermaking, a dry forming mold (DFM) was developed and evaluated. Main fanning section of DFM was a cylindrical tube, and at the top of the mold a stirring equipment was placed to disperse dry fibers. These fibers were screened using a hole type screen plate placed just under the stirring equipment and dropped freely on the fanning wire located 0.9 m below of the screen plate to form a dry fiber pad. The vertical and horizontal velocity of air flow in the forming cylinder were evaluated and analyzed to find the most effective method of air flow control in the cylinder. Humidification and pressing conditions to obtain a decent dry fanned papers were examined. Results showed dry fanned papers can be prepared with this dry forming mold. And this mold can be used to examine the effect of the papermaking process factors including pressing pressure, drying temperature, humidification on sheet quality of dry formed papers.

Lipid Metabolism and Peroxidation in Broiler Chicks under Chronic Heat Stress

  • Shim, K.S.;Hwang, K.T.;Son, M.W.;Park, Garng H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.8
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    • pp.1206-1211
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    • 2006
  • The effects of taurine supplementation on growth performance, serum and liver concentrations of lipid, fatty acid composition and lipid peroxidation in the livers of broilers under chronic heat exposure conditions were investigated. The chicks with a similar body weight were equally assigned to one of three controlled-environment chambers. The brolier chicks, which were kept at $34^{\circ}C$ were fed either with a control diet or the control diet supplemented with 0.8% taurine, whereas broiler chicks kept at $22^{\circ}C$ were fed a control diet. Both of the BW and BW gains of broilers maintained at a temperature of $34^{\circ}C$ were significantly lower than those of the control group, which was maintained at a temperature of $22^{\circ}C$ (p<0.05). However, taurine addition in the diet of birds submitted to heat stress siginficantly improved BW gain (p<0.05). The feed intake of chicks declined with increases in temperature. The relative liver and gall bladder weights of chicks fed the control diet and maintained at $34^{\circ}C$ were significantly lower than those measured in the control birds (p<0.05). However, dietary taurine was found to compensate for these reductions in liver and gall bladder weights. Relative weights of abdominal fat did not differ significantly among the three groups. Serum triglyceride concentrations were significantly lower in the chicks fed the control diet and maintained at $34^{\circ}C$ compare to those measured in the chicks fed the control diet at $22^{\circ}C$ (p<0.05). Heat stress resulted in a significant reduction in total lipid and triglyceride levels, but also increased the levels of total cholesterol in the liver (p<0.05). However, dietary taurine supplementation under the heat stress condition resulted in the recovery, to control levels, of serum triglyceride concentrations, as well as the amounts of total lipids, triglycerides, and cholesterol in the liver. The livers of chicks fed on taurine diets at $34^{\circ}C$ showed significantly higher proportions of C14:0, C16:1, C18:1, C18:2, and 20:3, and lower C18:0 and C20:4 proportions than those of chicks fed on control diets at the same temperature (p<0.05). The total levels of saturated fatty acids decreased, but monounsaturated fatty acids and unsaturated fatty acid levels increased in chicks fed the taurine diet, as compared to chicks fed the control diet at $34^{\circ}C$ (p<0.05). Peroxidizability indices were significantly lower in the heat-exposed chicks fed the taurine diet than in the non-taurine heat-exposed groups (p<0.05). In conclusion, dietary taurine results in an increase in the growth performances of chicks under heat stress conditions via improvements in lipid absorption and metabolism, as well as an induced reduction in lipid peroxidation.

Variations of Air Temperature, Relative Humidity and Pressure in a Low Pressure Chamber for Plant Growth (식물생장용 저압챔버 내의 기온, 상대습도 및 압력의 변화)

  • Park, Jong-Hyun;Kim, Yong-Hyeon
    • Journal of Bio-Environment Control
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    • v.18 no.3
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    • pp.200-207
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    • 2009
  • This study was conducted to analyze the variations of air temperature, relative humidity and pressure in a low pressure chamber for plant growth. The low pressure chamber was composed of an acrylic cylinder, a stainless plate, a mass flow controller, an elastomer pressure controller, a read-out-box, a vacuum pump, and sensors of air temperature, relative humidity, and pressure. The pressure leakage in the low pressure chamber was greatly affected by the material and connection method of tubes. The leakage rate in the low pressure chamber with the welding of the stainless tubes and a plate decreased by $0.21kPa{\cdot}h^{-1}$, whereas the leakage in the low pressure chamber with teflon tube and rubber O-ring was given by $1.03kPa{\cdot}h^{-1}$. Pressure in the low pressure chamber was sensitively fluctuated by the air temperature inside the chamber. An elastomer pressure controller was installed to keep the pressure in the low pressure chamber at a setting value. However, inside relative humidity at dark period increased to saturation level.. Two levels (25 and 50kPa) of pressure and two levels (500 and 1,000sccm) of mass flow rate were provided to investigate the effect of low pressure and mass flow rate on relative humidity inside the chamber. It was concluded that low setting value of pressure and high mass flow rate of mixed gas were the effective methods to control the pressure and to suppress the excessive rise of relative humidity inside the chamber.

Effects of Hardener and Extender Contents on Curing Behavior of Urea-Melamine-Formaldehyde Resin

  • Eom, Young-Geun;XU, Guang-Zhu;Lee, Young-Kyu;Kim, Hyun-Joong
    • Journal of the Korean Wood Science and Technology
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    • v.36 no.5
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    • pp.42-48
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    • 2008
  • This study was conducted to discuss the effects of hardener and extender contents on peak temperature, reaction enthalpy (${\Delta}H$), gelation time, viscosity change, and pH value in three types of UMF (urea-melamine- formaldehyde) resin with the help of perpHecT LogR meter, differential scanning calorimetry (DSC), and advanced rheometric expansion system (ARES), The results indicated that the pH value of Control A steeply decreased to 5,2 in the early stage but relatively remained constant thereafter as in Synthesis 1 and Synthesis 2, The peak temperature and time decreased as well, whereas ${\Delta}H$ and viscosity increased with the increase of hardener content. On the other hand, ${\Delta}H$ was not changed up to the extender content of 5% and then decreased with its further addition, And the pH value and peak temperature showed no change with the increase of extender content at the hardener content of 5% in three types of UMF resin, The effect of hardener content in this experiment, however, appeared more conspicuous in Control A than in the other two types of Synthesis 1 and Synthesis 2, These results might be caused by higher molecular weight with longer chains of methylene ($-CH_2-$) and methylene ($-CH_2-O-CH_2-$) ether bridges or much more branched chains in Control A.

Control Efficacy of Bacillus velezensis AFB2-2 against Potato Late Blight Caused by Phytophthora infestans in Organic Potato Cultivation

  • Kim, Min Jeong;Shim, Chang Ki;Park, Jong-Ho
    • The Plant Pathology Journal
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    • v.37 no.6
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    • pp.580-595
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    • 2021
  • Although late blight is an important disease in ecofriendly potato cultivation in Korea, it is highly dependent on the use of eco-friendly agricultural materials and the development of biological control technology is low. It is a necessary to develop an effective biocontrol agent to inactivate late blight in the field. AFB2-2 strain is a gram-positive with peritrichous flagella. It can utilize 20 types of carbon sources, like L-arabinose, and D-trehalose at 35℃. The optimal growth temperature of the strain is 37℃. It can survive at 20-50℃ in tryptic soy broth. The maximum salt concentration tolerated by AFB2-2 strain is 7.5% NaCl. AFB2-2 strain inhibited the mycelial growth of seven plant pathogens by an average inhibitory zone of 10.2 mm or more. Among the concentrations of AFB2-2, 107 cfu/ml showed the highest control value of 85.7% in the greenhouse. Among the three concentrations of AFB2-2, the disease incidence and severity of potato late blight at 107 cfu/ml was lowest at 0.07 and 6.7, respectively. The nucleotide sequences of AFB2-2 strain were searched in the NCBI GenBank; Bacillus siamensis strain KCTC 13613, Bacillus velezensis strain CR-502, and Bacillus amyloliquefaciens strain DSM7 were found to have a genetic similarity of 99.7%, 99.7%, and 99.5%, respectively. The AFB2-2 strain was found to harbor the biosynthetic genes for bacillomycin D, iturin, and surfactin. Obtained data recommended that the B. velezensis AFB2-2 strain could be considered as a promising biocontrol agent for P. infestans in the field.