Determination of chilling and heat requirements of pistachio (Pistacia vera L.) cultivars is important for satisfactory growth and development, particularly when large-scale commercial production is desired. This ex...Determination of chilling and heat requirements of pistachio (Pistacia vera L.) cultivars is important for satisfactory growth and development, particularly when large-scale commercial production is desired. This experiment was conducted to determine chilling requirement inducing vegetative and flower buds of Kalle-Ghuchi, Owhadi, Ahmad-Ahgaei, and Akbari pistachio. Shoots with enough vegetative and flower buds were taken from pistachio trees during autumn 2007 and 2008 when temperature reached to 15°C. Cuttings with flower buds were kept under (5 ± 1)°C for 0, 600, 650, 700, 750, 800, 850, 900, 950, 1 000, 1 050, 1 100, 1 150, 1 200, 1 250, and 1 300 h, respectively, and cuttings with vegetative buds were kept at 51°C until 1 500 h. The results indicated that pistachio cultivars requite chilling time between 750-1 400 h and heat requirements between 8 852-15 420 growing degree hours (GDH). Consequently, Kalle-Ghuchi had the lowest chilling (750-950 h), and heat (8 852-9 768 GDH) requirements, Ahmad-Aghaei and Owhadi had intermediate (1 000-1 250 h, 10 656- 13 320 GDH) and Akbari had the highest chilling (1 200-1 400 h) and heat (11 863-15 420 GDH) requirement.展开更多
The aim of the present study was to compare the accuracy and reproducibility of six statistical models for the calculation of olive (Olea europeae L.) heat requirements to trigger the onset of flowering in three Por...The aim of the present study was to compare the accuracy and reproducibility of six statistical models for the calculation of olive (Olea europeae L.) heat requirements to trigger the onset of flowering in three Portuguese regions: Reguengos de Monsaraz, Valenga do Douro, and Braga. Other alms were to ascertain the date on which the heat-accumulation period started and the threshold temperatures above which the development of reproductive structures starts in olives. The starting and peak dates for the regional O. europeae flowering season were estimated by monitoring airborne pollen from 1998 to 2004 using "Cour"- type samplers. The threshold temperature values calculated for the three regions were very similar (9.0 ℃ for Valenca do Douro, 9.2 ℃ for Reguengos de Monsaraz, and 9.7 ℃ for Braga). The accumulated daily mean temperature model had less interannual and inter-regional variation, showing best predictive results for 2004, with absolute differences between the observed and predicted dates of 4 d in Reguengos de Monsaraz and 2 d In Valenca do Douro and Braga for the onset of flowering date and of 2 d In Reguengos de Monsaraz, 7 d in Valenca do Douro, and 4 d in Braga for peak flowering dates. This model was the most accurate, reproducible, and operational to calculate heat requirements for olives to flower, with an average mean temperature accumulation of 1 446 ℃ In Reguengos, 1 642 ℃ in Valenga do Douro, and 1 703℃ In Braga to reach the onset of flowering. The best initial date for this accumulation was 1 January.展开更多
This paper is based on long term parameter measurements of the exhaust air heat pumps (EAHP) system in a new built apartment building. The building was equipped with an exhaust air ventilation system and exhaust air h...This paper is based on long term parameter measurements of the exhaust air heat pumps (EAHP) system in a new built apartment building. The building was equipped with an exhaust air ventilation system and exhaust air heat pump for ventilation heat recover. The results of the measurements show that the COP of the EAHP is mainly related to the temperature graph of the heating system and the supply temperature of domestic hot water (DWH). During the measurement period some other impact factors, such as the quality of maintenance, the nighttime temperature graph of the heating system, the reduction of the exhaust air flows in case of low temperatures, mistakes in designing and low building quality, have also played a role. An analysis of energy consumption shows that in winter conditions the COP is about 3.0 and in the transition period about 3.3. The energy recovery value of the EAHP is 0.5.展开更多
This article gives an overview of using the ground source heat pump (GSHP) and air-to-water heat pump (A&WHP) in cold climate areas for heating and for domestic hot water production of buildings. Computer simulati...This article gives an overview of using the ground source heat pump (GSHP) and air-to-water heat pump (A&WHP) in cold climate areas for heating and for domestic hot water production of buildings. Computer simulation and analysis were carried out for a typical detached house, with 200 m2 of living area, the heat demand of 9 kW and the average heat demand for DHW production of 1 kW. In heating period the average Coefficient of Performance (COP) of the A&WHP is considerably lower than COP of the GSHP.展开更多
Greenhouse vegetable production in Canadian Prairies is important for creating a sustainable regional food economy,especially in northern communities.This study included the estimation of heating demand for year-round...Greenhouse vegetable production in Canadian Prairies is important for creating a sustainable regional food economy,especially in northern communities.This study included the estimation of heating demand for year-round production and evaluation of the economic feasibility of greenhouse vegetable production(tomato,cucumber,and pepper)in a conceptually designed greenhouse(0.6 ha)located in remote northern communities in Saskatchewan,Canada.The heating simulation was based on a greenhouse heating simulation model(GREENHEAT)developed by the authors recently.The simulation results showed that the annual heating requirement for the production of tomato,cucumber,and pepper are 1486 MJ m^2,1657 MJ m^2,and 1754 MJ m^2,respectively.The economic analysis indicates the net return(NR)from the production of tomato,cucumber,and pepper,are C$69.2/m^2(in Canadian dollar,CAD),C$41.5/m^2,and C$43.8/m^2,respectively,based on the market price C$3.5/kg,C$2.7/kg,and C$8.0/kg,and yields of 55.0 kg m^-2,65.0 kg m^-2,and 23.0 kg m^-2.The net present value(NPV)for the tomato,cucumber,and pepper production are C$1.9 M,C$1.2 M,and C$1.1 M,respectively,and the benefit-cost ratio(BCR)are 1.38,1.21,and 1.21.The economic feasibility analysis indicates the year-round production of vegetables in a greenhouse at remote northern Saskatchewan would be economically profitable.展开更多
文摘Determination of chilling and heat requirements of pistachio (Pistacia vera L.) cultivars is important for satisfactory growth and development, particularly when large-scale commercial production is desired. This experiment was conducted to determine chilling requirement inducing vegetative and flower buds of Kalle-Ghuchi, Owhadi, Ahmad-Ahgaei, and Akbari pistachio. Shoots with enough vegetative and flower buds were taken from pistachio trees during autumn 2007 and 2008 when temperature reached to 15°C. Cuttings with flower buds were kept under (5 ± 1)°C for 0, 600, 650, 700, 750, 800, 850, 900, 950, 1 000, 1 050, 1 100, 1 150, 1 200, 1 250, and 1 300 h, respectively, and cuttings with vegetative buds were kept at 51°C until 1 500 h. The results indicated that pistachio cultivars requite chilling time between 750-1 400 h and heat requirements between 8 852-15 420 growing degree hours (GDH). Consequently, Kalle-Ghuchi had the lowest chilling (750-950 h), and heat (8 852-9 768 GDH) requirements, Ahmad-Aghaei and Owhadi had intermediate (1 000-1 250 h, 10 656- 13 320 GDH) and Akbari had the highest chilling (1 200-1 400 h) and heat (11 863-15 420 GDH) requirement.
基金supported by the National Natural Science Foundation of China(30424813)Science Publication Foundation of the Chinese Academy of Sciences
文摘The aim of the present study was to compare the accuracy and reproducibility of six statistical models for the calculation of olive (Olea europeae L.) heat requirements to trigger the onset of flowering in three Portuguese regions: Reguengos de Monsaraz, Valenga do Douro, and Braga. Other alms were to ascertain the date on which the heat-accumulation period started and the threshold temperatures above which the development of reproductive structures starts in olives. The starting and peak dates for the regional O. europeae flowering season were estimated by monitoring airborne pollen from 1998 to 2004 using "Cour"- type samplers. The threshold temperature values calculated for the three regions were very similar (9.0 ℃ for Valenca do Douro, 9.2 ℃ for Reguengos de Monsaraz, and 9.7 ℃ for Braga). The accumulated daily mean temperature model had less interannual and inter-regional variation, showing best predictive results for 2004, with absolute differences between the observed and predicted dates of 4 d in Reguengos de Monsaraz and 2 d In Valenca do Douro and Braga for the onset of flowering date and of 2 d In Reguengos de Monsaraz, 7 d in Valenca do Douro, and 4 d in Braga for peak flowering dates. This model was the most accurate, reproducible, and operational to calculate heat requirements for olives to flower, with an average mean temperature accumulation of 1 446 ℃ In Reguengos, 1 642 ℃ in Valenga do Douro, and 1 703℃ In Braga to reach the onset of flowering. The best initial date for this accumulation was 1 January.
文摘This paper is based on long term parameter measurements of the exhaust air heat pumps (EAHP) system in a new built apartment building. The building was equipped with an exhaust air ventilation system and exhaust air heat pump for ventilation heat recover. The results of the measurements show that the COP of the EAHP is mainly related to the temperature graph of the heating system and the supply temperature of domestic hot water (DWH). During the measurement period some other impact factors, such as the quality of maintenance, the nighttime temperature graph of the heating system, the reduction of the exhaust air flows in case of low temperatures, mistakes in designing and low building quality, have also played a role. An analysis of energy consumption shows that in winter conditions the COP is about 3.0 and in the transition period about 3.3. The energy recovery value of the EAHP is 0.5.
基金supported by the Estonian Research Council,with Institutional research funding grant IUT1-15with the project“Development of efficient tech-nologies for air change and ventilation necessary for the increase of energy efficiency of buildings,AR12045”,financed by SA Archimedesby the project“Civil and Environmental Engineering PhD School,DAR9085”.
文摘This article gives an overview of using the ground source heat pump (GSHP) and air-to-water heat pump (A&WHP) in cold climate areas for heating and for domestic hot water production of buildings. Computer simulation and analysis were carried out for a typical detached house, with 200 m2 of living area, the heat demand of 9 kW and the average heat demand for DHW production of 1 kW. In heating period the average Coefficient of Performance (COP) of the A&WHP is considerably lower than COP of the GSHP.
文摘Greenhouse vegetable production in Canadian Prairies is important for creating a sustainable regional food economy,especially in northern communities.This study included the estimation of heating demand for year-round production and evaluation of the economic feasibility of greenhouse vegetable production(tomato,cucumber,and pepper)in a conceptually designed greenhouse(0.6 ha)located in remote northern communities in Saskatchewan,Canada.The heating simulation was based on a greenhouse heating simulation model(GREENHEAT)developed by the authors recently.The simulation results showed that the annual heating requirement for the production of tomato,cucumber,and pepper are 1486 MJ m^2,1657 MJ m^2,and 1754 MJ m^2,respectively.The economic analysis indicates the net return(NR)from the production of tomato,cucumber,and pepper,are C$69.2/m^2(in Canadian dollar,CAD),C$41.5/m^2,and C$43.8/m^2,respectively,based on the market price C$3.5/kg,C$2.7/kg,and C$8.0/kg,and yields of 55.0 kg m^-2,65.0 kg m^-2,and 23.0 kg m^-2.The net present value(NPV)for the tomato,cucumber,and pepper production are C$1.9 M,C$1.2 M,and C$1.1 M,respectively,and the benefit-cost ratio(BCR)are 1.38,1.21,and 1.21.The economic feasibility analysis indicates the year-round production of vegetables in a greenhouse at remote northern Saskatchewan would be economically profitable.