The Experts below are selected from a list of 210 Experts worldwide ranked by ideXlab platform
Faith Olszewski - One of the best experts on this subject based on the ideXlab platform.
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automated cycled sprinkler irrigation for spring Frost Protection of cranberries
Agricultural Water Management, 2017Co-Authors: Faith Olszewski, Peter Jeranyama, Casey D Kennedy, Carolyn J DemoranvilleAbstract:Overhead (sprinkler) irrigation is commonly used for spring Frost Protection of cranberries in southeastern Massachusetts, United States. Historically, conventional forms of irrigation management have been used, generally consisting of running irrigation pumps continuously throughout the night and into the early morning until ambient air temperature reached 1–2°C above the critical temperature of the plant. However, a general paucity of information exists on the horticultural and hydrological effects of on-off “cycling” of irrigation pumps based on pre-programmed temperature setpoints. To fill this gap, three years of monitoring were conducted to quantify the relative effects of cycled and conventional spring Frost irrigation on cranberry bud damage, crop yield, and water use. Results showed that cycled irrigation reduced seasonal water use from 33 to 80% compared to conventional Frost irrigation, with water savings under cycled Frost irrigation ranging from 113 to 198mm (mean±SD: 176±47mm). Despite some variation in type and amount of observed bud damage, values of cranberry yield were similar between the two methods or higher for cycled irrigation. The conventional Frost irrigation method always applied more irrigation water, possibly increasing soil saturation and anaerobic conditions that are known to lower crop yield in cranberry. Together, these results point to cycled irrigation as a water management strategy that can enhance cranberry production and reduce agricultural water use in southeastern Massachusetts.
Richard L. Snyder - One of the best experts on this subject based on the ideXlab platform.
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Tea leaf’s microstructure and ultrastructure response to low temperature in indicating critical damage temperature
Elsevier, 2019Co-Authors: Richard L. Snyder, Eric R. KentAbstract:To find out the critical damage temperature of tea leaf, a new method of subzero treatment was provided by fitting the air temperature data from six heavy Frost events. Furthermore, the study explored the characteristics of Fuding Dabai tea plant response to low temperature stress of 2, 0, −2, −4, −8, −10 and −15 °C by observing the microstructure and ultrastructure changes of the leaves. All samples were collected in an ambient temperature of 8.6 °C which served as control. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to observe the microstructure and ultrastructure of stomata and mesophyll. SEM observation results indicated that stomata of tea leaves have an obvious low temperature stress when the temperature was lower than −2 °C. The extent of opening of the stomata increased and enhanced guard cell Protection of tea leaves against cold injury. However, dehydration, shrinkage and deformation of cells occurred as the temperature decreased from −2 °C to −15 °C. TEM observations showed that the cell nucleus, cell walls, chloroplasts and mitochondria all had normal structure at a temperature of 8.6 °C where the membrane and granum lamella were clearly visible. As the temperature decreased to −2 °C, the membrane system of tea leaf was the first to be damaged and the cell walls became fuzzy. Therefore, the leaf microstructure and ultrastructure showed obvious changes at −2 °C, which might define the critical damage temperature for freeze damage of Fuding Dabai tea. Control strategy based this critical damage temperature is useful for wind machine Frost Protection in tea fields within the Yangtze River region. Keywords: Frost damage, Freeze injury, Chill injury, Frost protectio
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comparative experiments and effectiveness evaluation on vertical blowing fans vbf for Frost Protection
International Journal of Agricultural and Biological Engineering, 2015Co-Authors: Hu Yongguang, Wu Wenye, Paulo J Meloabreu, T Shapland, Zhang Hong, Richard L. SnyderAbstract:Experiments were conducted to evaluate the performance of vertical blowing fans (VBF) for Frost Protection in a vineyard on a steep slope near Napa Valley in Northern California, USA, and a tea plantation located on undulating terrain in Zhenjiang, China. Minimum temperature comparisons from within the grape vineyard on nights with and without VBF operation with control station minimum temperatures exhibited no temperature benefit. Profile measurements from the test in China indicated that there was an increase in temperature when the VBF was first started, but that benefit was lost over time. No clear benefit from using the VBF was observed. Observation of Frost deposition and thermal imagery also showed no benefit except for within about 5 m of the VBF. Based on this work, the effectiveness of the VBF for Frost Protection was not validated. Keywords: Frost Protection, thermal inversion, weather modification, wind machines, vertical blowing fans (VBF), temperature DOI: 10.3965/j.ijabe.20150805.1419 Citation: Hu Y G, Wu W Y, De Melo-Abreu J P, Shapland T M, Zhang H, Snyder R L. Comparative experiments and effectiveness evaluation on vertical blowing fans (VBF) for Frost Protection. Int J Agric & Biol Eng, 2015; 8(5): 36－42.
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Operation effects of wind machines for Frost Protection of tea trees on different time scales
Transactions of the Chinese Society of Agricultural Machinery, 2013Co-Authors: Hu Yongguang, Zhu Xiaolan, Zhao Menglong, Richard L. Snyder, Li PingpingAbstract:Frost Protection effect experiments in tea fields were conducted according to wind machine operation timing on different time scales. The treatments of starting to use wind machines before tea sprouting,starting before Frost occurrence and stopping after sunrise were set up respectively. And the impact of wind machine operation on the growth of tea trees,temperature rise in the canopy and Protection coverage was measured. The results indicated that starting to use wind machines 20 d,15 d and 7 d before tea sprouting increased the length of young shoot,bud density and 100-bud weight by over 20% compared with the control test; Starting wind machines 2. 0 h,1. 5 h and 1. 0 h before Frost occurrenceled to better Protection and enlarged the coverage radius by more than 60% compared with the control test. Delayed stopping of wind machines by 2. 0 h,1. 5 h and 1. 0 h after sunrise reduced the temperature rise of the canopy by 45. 76% in the first hour,and narrowed the reduction of the photosynthetic intensity of tea leaves. Therefore,to protect tea trees from late Frost cold for better growth and yield,the appropriate application of wind machines should be more than 7 d prior to the tea budding, and the operation timing of starting and stopping for a certain Frost event should be 1. 0 h before Frost occurrence and 1. 0 h after sunrise,respectively.
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apple orchard Frost Protection with wind machine operation
Agricultural and Forest Meteorology, 2006Co-Authors: Antonio Ribeiro, Paulo J Meloabreu, Richard L. SnyderAbstract:Abstract Research has shown that wind machines are more effective under conditions of strong thermal inversions. Quantitative relationships between the level of Protection and inversion strength, however, are not well known, and there are few reports on the effect of fan operation on energy balance. Whether the wind machines should be started before surface cooling causes turbulence damping and atmospheric stratification or if it is possible to delay starting until just before the critical temperature occurs remains a matter of discussion. Therefore, experiments were conducted on 11 spring Frost nights during the 1999 and 2000 to assess the effectiveness of a fan operation on Frost Protection of an apple orchard under different microclimatic conditions. The 11 Frost events were characterized by light winds (0.58–1.92 m s −1 ) and clear skies for most of the night, resulting in an average accumulated radiative loss of 2.67 ± 0.38 MJ m −2 . The air temperature increased immediately after the wind machines were started and the temperature rise depended on inversion strength. For each 1 °C increase in temperature inversion strength between 1.5 and 15 m height, wind machine operation caused a 0.3 °C increase of air temperature at a 1.5 m height within the main area affected by the fan operation. Using multiple regression, the area protected was significantly related to the temperature increase and the inversion strength. Wind machine operation reduced flower damage by 60% in 1999 and 37% in 2000. Distribution of flower damage varied spatially, and it was related to wind drift.
Sergey Anisimov - One of the best experts on this subject based on the ideXlab platform.
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Frost formation and freeze Protection with bypass for counter flow recuperators
International Journal of Heat and Mass Transfer, 2017Co-Authors: Andrzej Jedlikowski, J Danielewicz, Michal Karpuk, Sergey Anisimov, Demis PandelidisAbstract:Abstract An accurate and efficient model based on the modified e-NTU method was developed for numerical simulations and analysis of coupled heat and mass transfer inside the counter-flow plate heat exchanger under Frosting operating conditions. The proposed model was validated with experimental data. The successful comparison between simulated and experimental data indicates that the developed model is capable to predict adequately operating performance of the counter-flow plate heat exchanger under sub-zero outdoor air temperature conditions. Three active heat and mass transfer areas were established in a counter-flow plate heat exchanger equipped with bypass damper and face and bypass dampers. The detail analysis of these particular heat and mass transfer zones creation revealed the most probable variants of year-round operating conditions of the counter-flow heat exchanger. The implementation of the particular variant of heat and mass transfer depends upon the relations of the temperatures in two decisive zones on the return air channel surface (in the “cold” and “hot” zone) and the value of the inlet return airflow dew point temperature. It was established, that the most unfavourable operating conditions at sub-zero outdoor air temperature occur at the value of inlet return air dew point temperature equalled to 0 °C. Unfortunately, such value of dew point temperature corresponds to the normal indoor air conditions in winter season. The values of critical outdoor temperatures were determined on the base of parametric Frosting limits analysis conducted under different inlet return airflow conditions for different values of heat recovery efficiency of the counter-flow plate heat exchanger at different opening levels of face and bypass dampers. It was established, that the Frost tends to take place with increasing temperature effectiveness of the heat exchanger. It was established, that the fully open bypass technique does not provide complete Frost Protection under sub-zero outdoor air temperature operating conditions.
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analysis of the Frost formation and freeze Protection with bypass for cross flow recuperators
Applied Thermal Engineering, 2017Co-Authors: Andrzej Jedlikowski, Sergey AnisimovAbstract:Abstract A theoretical analysis of coupled heat and mass transfer inside the cross-flow plate heat exchanger used for energy recovery under Frosting operating conditions was presented. Three selected Frost control techniques were analysed on the base of original e-NTU model. Frost-free operating conditions were determined for the cross-flow plate heat exchanger under different opening levels of bypass damper and face and bypass dampers . It was found that the implementation of the particular variant of heat exchanger performance and the values of critical outdoor temperatures for different operating conditions in which the onset of Frosting occurs in the cross-flow flat plate heat exchanger depend upon the heat and mass transfer conditions realized in two decisive points on the return air channel surface known as the “ cold corner ” and “ hot corner ”. It was concluded, that the fully open bypass technique does not provide complete Frost Protection under sub-zero outdoor air temperature operating conditions.
Andrzej Jedlikowski - One of the best experts on this subject based on the ideXlab platform.
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Frost formation and freeze Protection with bypass for counter flow recuperators
International Journal of Heat and Mass Transfer, 2017Co-Authors: Andrzej Jedlikowski, J Danielewicz, Michal Karpuk, Sergey Anisimov, Demis PandelidisAbstract:Abstract An accurate and efficient model based on the modified e-NTU method was developed for numerical simulations and analysis of coupled heat and mass transfer inside the counter-flow plate heat exchanger under Frosting operating conditions. The proposed model was validated with experimental data. The successful comparison between simulated and experimental data indicates that the developed model is capable to predict adequately operating performance of the counter-flow plate heat exchanger under sub-zero outdoor air temperature conditions. Three active heat and mass transfer areas were established in a counter-flow plate heat exchanger equipped with bypass damper and face and bypass dampers. The detail analysis of these particular heat and mass transfer zones creation revealed the most probable variants of year-round operating conditions of the counter-flow heat exchanger. The implementation of the particular variant of heat and mass transfer depends upon the relations of the temperatures in two decisive zones on the return air channel surface (in the “cold” and “hot” zone) and the value of the inlet return airflow dew point temperature. It was established, that the most unfavourable operating conditions at sub-zero outdoor air temperature occur at the value of inlet return air dew point temperature equalled to 0 °C. Unfortunately, such value of dew point temperature corresponds to the normal indoor air conditions in winter season. The values of critical outdoor temperatures were determined on the base of parametric Frosting limits analysis conducted under different inlet return airflow conditions for different values of heat recovery efficiency of the counter-flow plate heat exchanger at different opening levels of face and bypass dampers. It was established, that the Frost tends to take place with increasing temperature effectiveness of the heat exchanger. It was established, that the fully open bypass technique does not provide complete Frost Protection under sub-zero outdoor air temperature operating conditions.
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analysis of the Frost formation and freeze Protection with bypass for cross flow recuperators
Applied Thermal Engineering, 2017Co-Authors: Andrzej Jedlikowski, Sergey AnisimovAbstract:Abstract A theoretical analysis of coupled heat and mass transfer inside the cross-flow plate heat exchanger used for energy recovery under Frosting operating conditions was presented. Three selected Frost control techniques were analysed on the base of original e-NTU model. Frost-free operating conditions were determined for the cross-flow plate heat exchanger under different opening levels of bypass damper and face and bypass dampers . It was found that the implementation of the particular variant of heat exchanger performance and the values of critical outdoor temperatures for different operating conditions in which the onset of Frosting occurs in the cross-flow flat plate heat exchanger depend upon the heat and mass transfer conditions realized in two decisive points on the return air channel surface known as the “ cold corner ” and “ hot corner ”. It was concluded, that the fully open bypass technique does not provide complete Frost Protection under sub-zero outdoor air temperature operating conditions.
Carolyn J Demoranville - One of the best experts on this subject based on the ideXlab platform.
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automated cycled sprinkler irrigation for spring Frost Protection of cranberries
Agricultural Water Management, 2017Co-Authors: Faith Olszewski, Peter Jeranyama, Casey D Kennedy, Carolyn J DemoranvilleAbstract:Overhead (sprinkler) irrigation is commonly used for spring Frost Protection of cranberries in southeastern Massachusetts, United States. Historically, conventional forms of irrigation management have been used, generally consisting of running irrigation pumps continuously throughout the night and into the early morning until ambient air temperature reached 1–2°C above the critical temperature of the plant. However, a general paucity of information exists on the horticultural and hydrological effects of on-off “cycling” of irrigation pumps based on pre-programmed temperature setpoints. To fill this gap, three years of monitoring were conducted to quantify the relative effects of cycled and conventional spring Frost irrigation on cranberry bud damage, crop yield, and water use. Results showed that cycled irrigation reduced seasonal water use from 33 to 80% compared to conventional Frost irrigation, with water savings under cycled Frost irrigation ranging from 113 to 198mm (mean±SD: 176±47mm). Despite some variation in type and amount of observed bud damage, values of cranberry yield were similar between the two methods or higher for cycled irrigation. The conventional Frost irrigation method always applied more irrigation water, possibly increasing soil saturation and anaerobic conditions that are known to lower crop yield in cranberry. Together, these results point to cycled irrigation as a water management strategy that can enhance cranberry production and reduce agricultural water use in southeastern Massachusetts.
