Control of Greenhouse Environmental Conditions with IOT Based Monitoring and Analysis System

Directory of Open Access Journals (Sweden)

Ali Çaylı

2017-10-01

Full Text Available Wireless sensor networks applications and inter-machine communication (M2M, called the Internet of Things, help decision-makers to control complex systems thanks to the low data-rate and cost-effective data collection and analysis. These technologies offer new possibilities to monitor environmental management and agricultural policies, and to improve agricultural production, especially in low-income rural areas. In this study, IoT is proposed with a low cost, flexible and scalable data collection and analysis system. For this purpose, open source hardware microprocessor cards and sensors are stored in the greenhouse computer database using the IEEE 802.15.4 Zigbee wireless communication protocol. The data can be analyzed by greenhouse computer analysis software, which is developed with the PHP programming language. It is possible to monitor the real time data from the greenhouse computer. Also alert rules definitions can be made and the system was tested in greenhouse conditions. It has been observed that it performs operations steadily such as data transfer, sensor measurements and data processing. The proposed system may be useful for monitoring indoor climate and controlling ventilation, irrigation and heating systems, especially for small enterprises due to the modular structure.

Adaptation of a leaf wetness duration model for tomato under Colombian greenhouse conditions

Directory of Open Access Journals (Sweden)

Rodrigo Gil

2015-04-01

Full Text Available Greenhouse tomato production uses structures that protect crops from extreme environmental conditions; however, the climate inside Colombian greenhouses is often not optimal and crops are susceptible to attack by fungal diseases. The use of simulation models for early warnings of attack by diseases have helped to rationalize the use of chemical pesticides by increasing their efficiency when sprayed at critical times of disease onset. The aim of this study was to calibrate the surface wetness energy balance (SWEB model to estimate the leaf wetness duration (LWD for greenhouse tomatoes in the Alto Ricaurte province (Boyaca. For the validation, the performances of the SWEB model were evaluated by comparing a simulated LWD with records from dielectric leaf wetness sensors. The model adequately represented the phenomenon of free water on the leaves for plants in two greenhouses of Santa Sofia and Sutamarchan. The model simulated an average LWD of 9.9 and 12.1 hours day-1 in Santa Sofia and Sutamarchan, respectively. However, the simulations for the two greenhouses indicated different behaviors, with average differences between the observed and simulated daily number of hours with free water of 0.8 hours for Santa Sofia, while, for Sutamarchan, the difference reached 4 hours. The fraction of correct estimates index indicated the model had the ability to correctly predict 92 and 72% of the hours with a presence or absence of LWD in Santa Sofia and Sutamarchan, respectively. The SWEB model is a useful tool for early warnings for the attack of fungal diseases in greenhouse tomatoes. However, due to the shortcomings of the greenhouse structures used for production, the crops are highly susceptible to attack from these pathogens.

Design and Development a Control and Monitoring System for Greenhouse Conditions Based-On Multi Agent System

Directory of Open Access Journals (Sweden)

Seyed Hamidreza Kasaei

2011-12-01

Full Text Available The design of a multi-agent system for integrated management of greenhouse production is described. The model supports the integrated greenhouse production, with targets set to quality and quantity of produce with the minimum possible cost in resources and environmental consequences.
In this paper, we propose a real time and robust system for monitoring and control of the greenhouse condition which can automatically control of greenhouse temperature, lights, humidity, CO2 concentration, sunshine, pH, salinity, water available, soil temperature and soil nutrient for efficient production. We will propose a multi-agent methodology for integrated management systems in greenhouses. In this regards wireless sensor networks play a vital role to monitor
greenhouse and environment parameters. Each control process of the greenhouse environment is modeled as an autonomous agent with its own inputs, outputs and its own interactions with the other agents. Each agent acts autonomously, as it knows a priori the desired environmental setpoints. Many researchers have been making attempts to develop the greenhouse environment management system. The existing environment management systems are bulky, very costly and difficult to maintain. In the last years, Multi Agent Systems and Wireless Sensor Networks are becoming important solutions to this problem. This paper describes the implementation and
configuration of the wireless sensor network to monitor and control various parameter of greenhouse. The developed system is simple, cost effective, and easily installable.

Effect of the Evaporative Cooling on the Human Thermal Comfort and Heat Stress in a Greenhouse under Arid Conditions

Directory of Open Access Journals (Sweden)

A. M. Abdel-Ghany

2013-01-01

Full Text Available Thermal sensation and heat stress were evaluated in a plastic greenhouse, with and without evaporative cooling, under arid climatic conditions in Riyadh, Saudi Arabia. Suitable thermal comfort and heat stress scales were selected for the evaluation. Experiments were conducted in hot sunny days to measure the required parameters (i.e., the dry and wet bulb temperatures, globe temperature, natural wet bulb temperature, and solar radiation flux in the greenhouse. The results showed that in the uncooled greenhouse, workers are exposed to strong heat stress and would feel very hot most of the day time; they are safe from heat stress risk and would feel comfortable during night. An efficient evaporative cooling is necessary during the day to reduce heat stress and to improve the comfort conditions and is not necessary at night. In the cooled greenhouse, workers can do any activity: except at around noon they should follow a proposed working schedule, in which the different types of work were scheduled along the daytimes based on the heat stress value. To avoid heat stress and to provide comfort conditions in the greenhouses, the optimum ranges of relative humidity and air temperature are 48–55% and 24–28°C, respectively.

An Investigation about using Nanorefrigerants in Air Conditioning Systems According to the Theoretical, CFD and Experimental Review of the Recent Literature

Directory of Open Access Journals (Sweden)

Farshad Panahizadeh

2016-10-01

Full Text Available Greenhouse gases (GHG causing global warming and climate change. In the year 2014, 32.3 billion tones CO2 emitted to the atmosphere as the most important greenhouse gas. According to the statistics, a significant portion of this amount is related to electricity demand of air conditioning systems, for producing a one ton of refrigeration in HVAC air cooled or water cooled systems respectively 1026 and 764 grams GHG emitted in the atmosphere. Therefore, air conditioning systems have an important role in the global warming and climate change. By increasing the COP of air conditioning systems the electricity demand of them reduced. One strategy for increasing the COP of air conditioning systems is using nanorefrigerants. In the present study, a comprehensive information is given regarding to use nanorefrigerants in air conditioning systems according to the theoretical, CFD and experimental review of the recent literature. This paper gives assistance to designers of air conditioning systems in their future efforts for selecting refrigerant for their systems

The use of 32p labelled fertilizer in field and greenhouse

Energy Technology Data Exchange (ETDEWEB)

NONE

1983-12-31

This training film deals with the use of 32p-labelled materials in field and greenhouse experimentation in soil-plant relationship studies. All technical aspects, including safe handling and radiation protection procedures to be considered in the layout and harvesting of field experiments are documented in detail. Procedures followed in the evaluation of P fertilizers (such as rock phosphates) under greenhouse conditions are described. Several soil injection techniques available for the determination of the root activity pattern of trees are shown

Greenhouse cooling and heat recovery using fine wire heat exchangers in a closed pot plant greenhouse: design of an energy producing greenhouse

NARCIS (Netherlands)

Bakker, J.C.; Zwart, de H.F.; Campen, J.B.

2006-01-01

A greenhouse cooling system with heat storage for completely closed greenhouses has been designed, based on the use of a fine wire heat exchanger. The performance of the fine wire heat exchangers was tested under laboratory conditions and in a small greenhouse compartment. The effects of the system

Pot plant production, environmental conditions and energy consumption in insulated greenhouses

Energy Technology Data Exchange (ETDEWEB)

Bjerre, H.; Amsen, M.G. (Statens Planteavlsforsoeg, Havebrugscentret, Institut for Vaeksthuskulturer, Aarslev, Denmark)

1984-01-01

An energy experiment with 4 different types of greenhouses was carried out in the winter 1980-81 and 1981-82. Three of these greenhouses were insulated. The reference house was a single layer glasshouse with a mobile shading curtain, which was drawn at night. A comparison with the reference house showed the following energy savings for the insulated houses: Double glass 29-32%, double acryllic 39%, and thermal screens 22-24%. On average the air humidity was 80-86% RH in the double acryllic greenhouse and in the double glass house, whereas the levels was 5-10% lower in the 2 greenhouses with single glass. In spite of the high air humidity in the permanently insulated houses, no plant diseases occurred. The dry matter production of seven plant species was recorded in all greenhouses on the same date. Compared with the reference house 3 of the plant species showed a 5-10% higher production in the double acryllic greenhouse as well as the house with thermal screens. The remaining 4 plant species did not show any differences, between the 3 greenhouses. In the double glass house the production was considerably lower. To study the growth in detail, Tagetes plants were grown for 3-week periods during the winter in all houses. The aim of this study was to investigate whether the ratio between the growth in the 4 greenhouses was the same when periods of high light intensity were compared to periods with low light intensity. No characteristic changes with increasing light intensities could be observed between the different greenhouses. The differences between the greenhouses in time of production for the pot plants were generally small. The most remarkable difference in plant quality between the houses could be seen with Chrysanthemum and Kalanchoe. These 2 plant species were considerably less compact in the double acryllic greenhouse. Chrysanthemum was also less compact in the double glass house.

Irrigation water consumption modelling of a soilless cucumber crop under specific greenhouse conditions in a humid tropical climate

Directory of Open Access Journals (Sweden)

Galo Alberto Salcedo

Full Text Available ABSTRACT: The irrigation water consumption of a soilless cucumber crop under greenhouse conditions in a humid tropical climate has been evaluated in this paper in order to improve the irrigation water and fertilizers management in these specific conditions. For this purpose, a field experiment was conducted. Two trials were carried out during the years 2011 and 2014 in an experimental farm located in Vinces (Ecuador. In each trial, the complete growing cycle of a cucumber crop grown under a greenhouse was evaluated. Crop development was monitored and a good fit to a sigmoidal Gompertz type growth function was reported. The daily water uptake of the crop was measured and related to the most relevant indoor climate variables. Two different combination methods, namely the Penman-Monteith equation and the Baille equation, were applied. However, the results obtained with these combination methods were not satisfactory due to the poor correlation between the climatic variables, especially the incoming radiation, and the crop's water uptake (WU. On contrary, a good correlation was reported between the crop's water uptake and the leaf area index (LAI, especially in the initial crop stages. However, when the crop is fully developed, the WU stabilizes and becomes independent from the LAI. A preliminary model to simulate the water uptake of the crop was adjusted using the data obtained in the first experiment and then validated with the data of the second experiment.

Nitrogen utilization of vegetables grown under plastic greenhouse conditions in Ankara using 15N technique

International Nuclear Information System (INIS)

Halitligil, M.B.; Kislal, H.; Sirin, H.; Sirin, C.; Kilicaslan, A.

2004-01-01

In order to find suitable varieties of tomato, pepper and cucumber for plastic greenhouse conditions in Ankara and eventually to identify the best N fertilizer rate greenhouse experiments were conducted for two years. Yazgi F 1 variety for tomato, Hizir F 1 variety for cucumber and Serademre 8 variety for pepper were chosen to be the suitable varieties to grow in the plastic greenhouse conditions in Ankara. Five N treatments [N 0 =0, N 1 =150, N 2 =300, and N 3 =450 kg/ha; also, soil N application treatment (N soil ) equivalent to the fertigation treatment of 300 kg/ha was included for tomato and pepper, however N rates for cucumber was 131, 266 and 339 kg N/ha; N soil being 266 kg N/ha] were investigated using 15 N labeled urea fertilizer. Significantly higher marketable fresh fruit and total dry matter yields and N uptakes values were obtained from N 3 treatments for tomato and cucumber, but from N 2 treatment for pepper. Also, significantly higher yields, N uptakes and % NUE values were obtained when the same amount of N fertilizer is applied through fertigation compared to the treatment where N fertilizer applied to the soil then drip irrigated. (author)

Energy and Greenhouse Gas Emission Assessment of Conventional and Solar Assisted Air Conditioning Systems

Directory of Open Access Journals (Sweden)

Xiaofeng Li

2015-11-01

Full Text Available Energy consumption in the buildings is responsible for 26% of Australia’s greenhouse gas emissions where cooling typically accounts for over 50% of the total building energy use. The aim of this study was to investigate the potential for reducing the cooling systems’ environmental footprint with applications of alternative renewable energy source. Three types of cooling systems, water cooled, air cooled and a hybrid solar-based air-conditioning system, with a total of six scenarios were designed in this work. The scenarios accounted for the types of power supply to the air-conditioning systems with electricity from the grid and with a solar power from highly integrated building photovoltaics (BIPV. Within and between these scenarios, systems’ energy performances were compared based on energy modelling while the harvesting potential of the renewable energy source was further predicted based on building’s detailed geometrical model. The results showed that renewable energy obtained via BIPV scenario could cover building’s annual electricity consumption for cooling and reduce 140 tonnes of greenhouse gas emissions each year. The hybrid solar air-conditioning system has higher energy efficiency than the air cooled chiller system but lower than the water cooled system.

Paternal inheritance of plastid-encoded transgenes in Petunia hybrida in the greenhouse and under field conditions

Directory of Open Access Journals (Sweden)

Patricia Horn

2017-12-01

Full Text Available As already demonstrated in greenhouse trials, outcrossing of transgenic plants can be drastically reduced via transgene integration into the plastid. We verified this result in the field with Petunia, for which the highest paternal leakage has been observed. The variety white 115 (W115 served as recipient and Pink Wave (PW and the transplastomic variant PW T16, encoding the uidA reporter gene, as pollen donor. While manual pollination in the greenhouse led to over 90% hybrids for both crossings, the transgenic donor resulted only in 2% hybrids in the field. Nevertheless paternal leakage was detected in one case which proves that paternal inheritance of plastid-located transgenes is possible under artificial conditions. In the greenhouse, paternal leakage occurred in a frequency comparable to published results. As expected natural pollination reduced the hybrid formation in the field from 90 to 7.6% and the transgenic donor did not result in any hybrid. Keywords: Paternal plastid inheritance, Transgene confinement, Greenhouse, Field trial, Pollen mediated gene flow

Effect of torrefaction conditions on greenhouse crop residue: Optimization of conditions to upgrade solid characteristics.

Science.gov (United States)

Iáñez-Rodríguez, Irene; Martín-Lara, María Ángeles; Blázquez, Gabriel; Pérez, Antonio; Calero, Mónica

2017-11-01

This work investigated the possibility of using a greenhouse crop waste as a fuel, since it is an abundant residue in the Mediterranean area of Spain. The residue is mainly composed by biomass with a little quantity of plastic. The physical and chemical characteristics of the biomass were determined by elemental analysis, proximate analysis, FT-IR, FE-SEM and thermogravimetry. Additionally, a torrefaction process was carried out as a pre-treatment to improve the energy properties of the biomass material. The optimal conditions (time and temperature) of torrefaction were found to be 263°C and 15min using the gain and loss method. Further studies were carried out with the sample prepared with the nearest conditions to the optimal in order to determine the effect of the plastic fraction in the characteristics and torrefaction process of the waste studied. Copyright © 2017 Elsevier Ltd. All rights reserved.

Relations between radiation fluxes of a greenhouse in semi-arid conditions

International Nuclear Information System (INIS)

Al-Riahi, M.; Al-Karaghouli, A.; Hasson, A.M.; Al-Kayssi, A.W.

1989-01-01

Measurements of global radiation, reflected radiation and net total radiation inside and outside the greenhouse were conducted in Fudhiliyah Agrometeorological Research Station during the period from 1 January to 30 April, 1987. From these measurements, several relationships were established. Linear regressions of hourly values of global radiation inside the greenhouse on hourly global radiation outside the greenhouse were fitted for each month of the recording period. The degree of fit was generally good (r > 0.95). Net short-wave radiation inside the greenhouse showed strong dependence on the global inside radiation (r = 0.998), also the net total radiation and global radiation inside the greenhouse correlate very strongly. From the above-mentioned relationships, it was found that the global, net short-wave and net total radiation could be successfully predicted when only global outside radiation is available. Using the linear regression equations correlating the above radiation parameters, albedo and heating coefficient were derived. Albedo showed strong dependence on solar altitude angle and period of day (forenoon and afternoon). Heating coefficients were consistently positive and their values varied between 0.10 and 0.393. Monthly average values of mean hourly night-time net long-wave radiation inside the greenhouse were −31, −32, −38 and −42 W m −2 for the months of January, February, March and April, respectively

Effects of Biochar on the Net Greenhouse Gas Emissions under Continuous Flooding and Water-Saving Irrigation Conditions in Paddy Soils

Directory of Open Access Journals (Sweden)

Le Qi

2018-05-01

Full Text Available In this study, we investigated the greenhouse gas emission under different application of biochar in the conditions of continuous flooding and water-saving irrigation in paddy fields, whereas, plant and soil carbon sequestration were considered in the calculation of net greenhouse gas emissions. The emission rates of methane (CH4, carbon dioxide (CO2, and nitrous oxide (N2O gases were simultaneously monitored once every 7–10 days using the closed-chamber method. As a whole, the net greenhouse gas emission in the water-saving irrigation was more than that of the continuous flooding irrigation conditions. Compared with the water-saving irrigation, the continuous flooding irrigation significantly increased the CH4 in the control (CK and chemical fertilizer treatments (NPK. The CO2 emissions increased in each treatment of the water-saving irrigation condition, especially in the chemical fertilizer treatments (NPKFW. Similarly, the soil N2O emission was very sensitive to the water-saving irrigation condition. An interesting finding is that the biochar application in soils cut down the soil N2O emission more significantly than NPKFW in the water-saving irrigation condition while the effect of biochar increased under the continuous flooding irrigation condition.

Measurement and Modeling of Cucumber Evapotranspiration Under Greenhouse Condition

Directory of Open Access Journals (Sweden)

R. Moazenzadeh

2017-01-01

Full Text Available Introduction: In two last decades, greenhouse cultivation of different plants has developed among Iranian farmers, approximately 45 percent of national greenhouse cultures consisting of cucumber, tomato and pepper. As huge amounts of agricultural water in Iran are extracted from groundwater resources and a large number of Iranian plains are in critical conditions, and because irrigation is the major consumer of water (95 percent, it must be performed in a scientific manner. One approach to this is to obtain the knowledge of the consumptive use of major crops which is named evapotranspiration (ETc. Materials and Methods: This research was carried out in a north-south greenhouse belonging to Plant Protection Research Institute, located on northern Tehran, Iran, for estimating greenhouse cucumber evapotranspiration. Trickle irrigation method was used, and meteorological data such as temperature, humidity and solar radiation were measured daily. Physical and chemical measurements were conducted and electric conductivity (EC and pH values of 3.42 dsm-1 and 7.19, respectively, were recorded. Soil texture and bulk density were measured as to be sandy loam and 1.4 gr cm-3, respectively. In order to measure the actual evapotranspiration, cucumber seeds were also cultured in six similar microlysimeters and irrigation of each microlysimeter was based on FC moisture. If any drained water was available, it was measured. Finally, with measured meteorological characteristics in greenhouse which are suggested to have an effect on ET and were measurable, the best multiple linear regression and artificial neural network were established. The average data from three microlysimeters were used for calibration and that from three other microlysimeters were used for validation set. Results and Discussion: In the former case, when we used one multiple linear regression with measurable meteorological variables inside the greenhouse to predict cucumber ET for the entire

Greenhouse effect: an issue for the refrigeration and air conditioning sector; Effet de serre: quelle problematique pour le froid et le conditionnement de l`air?

Energy Technology Data Exchange (ETDEWEB)

Billiard, F. [Institut International du Froid, 75 - Paris (France)

1997-12-31

The principles of greenhouse effect and the greenhouse gas main direct and indirect emission sources due to refrigeration and air conditioning systems are first reviewed. Evolution scenarios from 1992 to 2020 and 2100 for the emissions of CFC, HCFC and HFC are presented and related to the Kyoto protocol project limitations; technical improvements in refrigerating and air conditioning systems (lower refrigerant utilization, fluid confinement, alternative technologies, natural refrigerant utilization, etc.) could lead to substantial diminutions of these greenhouse gases

Paternal inheritance of plastid-encoded transgenes in Petunia hybrida in the greenhouse and under field conditions.

Science.gov (United States)

Horn, Patricia; Nausch, Henrik; Baars, Susanne; Schmidtke, Jörg; Schmidt, Kerstin; Schneider, Anja; Leister, Dario; Broer, Inge

2017-12-01

As already demonstrated in greenhouse trials, outcrossing of transgenic plants can be drastically reduced via transgene integration into the plastid. We verified this result in the field with Petunia , for which the highest paternal leakage has been observed. The variety white 115 (W115) served as recipient and Pink Wave (PW) and the transplastomic variant PW T16, encoding the uid A reporter gene, as pollen donor. While manual pollination in the greenhouse led to over 90% hybrids for both crossings, the transgenic donor resulted only in 2% hybrids in the field. Nevertheless paternal leakage was detected in one case which proves that paternal inheritance of plastid-located transgenes is possible under artificial conditions. In the greenhouse, paternal leakage occurred in a frequency comparable to published results. As expected natural pollination reduced the hybrid formation in the field from 90 to 7.6% and the transgenic donor did not result in any hybrid.

Agricultural greenhouse with storage of sensible and latent heat in the soil. Modeling and simulation of thermal and hydric transfer. Experimental validation

Energy Technology Data Exchange (ETDEWEB)

Al Cheikh Kassem, N.; Miriel, J.; Roux, A. [Institut National des Sciences Appliquees (INSA), 35 - Rennes (France)

1993-12-31

This work presents a simulation model of sensible and latent heat storage in the soil of an agricultural greenhouse. Results recorded by the laboratory device of grounded storage and thermo-physic parameter values of soil experimentally obtained by a three rod thermal shock probe are used for checking the simulation model and thus assessing the performance of such a system and the coupling between the greenhouse and the storage. (Authors). 3 refs., 6 figs.

Dissipation and Residues of Pyrethrins in Leaf Lettuce under Greenhouse and Open Field Conditions.

Science.gov (United States)

Pan, Lixiang; Feng, Xiaoxiao; Zhang, Hongyan

2017-07-21

Pyrethrins are nowadays widely used for prevention and control of insects in leaf lettuce. However, there is a concern about the pesticide residue in leaf lettuce. A reliable analytical method for determination of pyrethrins (pyrethrin-and П, cinerin І and П, and jasmolin І and П) in leaf lettuce was developed by using gas chromatography-mass spectrometry (GC-MS). Recoveries of pyrethrins in leaf lettuce at three spiking levels were 99.4-104.0% with relative standard deviations of 0.9-3.1% ( n = 5). Evaluation of dissipation and final residues of pyrethrins in leaf lettuce were determined at six different locations, including the open field, as well as under greenhouse conditions. The initial concentration of pyrethrins in greenhouse (0.57 mg/kg) was higher than in open field (0.25 mg/kg) and the half-life for pyrethrins disappearance in field lettuce (0.7 days) was less than that greenhouse lettuce (1.1 days). Factors such as rainfall, solar radiation, wind speed, and crop growth rate are likely to have caused these results. The final residue in leaf lettuce was far below the maximum residue limits (MRLs) (1 mg/kg established by the European Union (EU), Australia, Korea, Japan).

The Greenhouse and Anti-Greenhouse Effects on Titan

Science.gov (United States)

McKay, C. P.; Cuzzi, Jeffrey N. (Technical Monitor)

1994-01-01

Titan is the largest moon of Saturn and is the only moon in the solar system with a substantial atmosphere. Its atmosphere is mostly made of nitrogen, with a few percent CH4, 0.1% H2 and an uncertain level of Ar (less than 10%). The surface pressure is 1.5 atms and the surface temperature is 95 K, decreasing to 71 at the tropopause before rising to stratospheric temperatures of 180 K. In pressure and composition Titan's atmosphere is the closest twin to Earth's. The surface of Titan remains unknown, hidden by the thick smog layer, but it may be an ocean of liquid methane and ethane. Titan's atmosphere has a greenhouse effect which is much stronger than the Earth's - 92% of the surface warming is due to greenhouse radiation. However an organic smog layer in the upper atmosphere produces an anti-greenhouse effect that cuts the greenhouse warming in half - removing 35% of the incoming solar radiation. Models suggest that during its formation Titan's atmosphere was heated to high temperatures due to accretional energy. This was followed by a cold Triton-like period which gradually warmed to the present conditions. The coupled greenhouse and haze anti-greenhouse may be relevant to recent suggestions for haze shielding of a CH4 - NH3 early atmosphere on Earth or Mars. When the NASA/ESA mission to the Saturn System, Cassini, launches in a few years it will carry a probe that will be sent to the surface of Titan and show us this world that is strange and yet in many ways similar to our own.

A validated physical model of greenhouse climate

International Nuclear Information System (INIS)

Bot, G.P.A.

1989-01-01

In the greenhouse model the momentaneous environmental crop growth factors are calculated as output, together with the physical behaviour of the crop. The boundary conditions for this model are the outside weather conditions; other inputs are the physical characteristics of the crop, of the greenhouse and of the control system. The greenhouse model is based on the energy, water vapour and CO 2 balances of the crop-greenhouse system. While the emphasis is on the dynamic behaviour of the greenhouse for implementation in continuous optimization, the state variables temperature, water vapour pressure and carbondioxide concentration in the relevant greenhouse parts crop, air, soil and cover are calculated from the balances over these parts. To do this in a proper way, the physical exchange processes between the system parts have to be quantified first. Therefore the greenhouse model is constructed from submodels describing these processes: a. Radiation transmission model for the modification of the outside to the inside global radiation. b. Ventilation model to describe the ventilation exchange between greenhouse and outside air. c. The description of the exchange of energy and mass between the crop and the greenhouse air. d. Calculation of the thermal radiation exchange between the various greenhouse parts. e. Quantification of the convective exchange processes between the greenhouse air and respectively the cover, the heating pipes and the soil surface and between the cover and the outside air. f. Determination of the heat conduction in the soil. The various submodels are validated first and then the complete greenhouse model is verified

Effect of greenhouse conditions on the leaf apoplastic proteome of Coffea arabica plants.

Science.gov (United States)

Guerra-Guimarães, Leonor; Vieira, Ana; Chaves, Inês; Pinheiro, Carla; Queiroz, Vagner; Renaut, Jenny; Ricardo, Cândido P

2014-06-02

This work describes the coffee leaf apoplastic proteome and its modulation by the greenhouse conditions. The apoplastic fluid (APF) was obtained by leaf vacuum infiltration, and the recovered proteins were separated by 2-DE and subsequently identified by matrix assisted laser desorption/ionization time of flight-mass spectrometry, followed by homology search in EST coffee databases. Prediction tools revealed that the majority of the 195 identified proteins are involved in cell wall metabolism and in stress/defense responses. Although most of the proteins follow the classical secretory mechanism, a low percentage of them seem to result from unconventional secretion (leaderless secreted proteins). Principal components analysis revealed that the APF samples formed two distinct groups, with the temperature amplitude mostly contributing for this separation (higher or lower than 10°C, respectively). Sixty one polypeptide spots allowed defining these two groups and 28 proteins were identified, belonging to carbohydrate metabolism, cell wall modification and proteolysis. Interestingly stress/defense proteins appeared as more abundant in Group I which is associated with a higher temperature amplitude. It seems that the proteins in the coffee leaf APF might be implicated in structural modifications in the extracellular space that are crucial for plant development/adaptation to the conditions of the prevailing environment. This is the first detailed proteomic study of the coffee leaf apoplastic fluid (APF) and of its modulation by the greenhouse conditions. The comprehensive overview of the most abundant proteins present in the extra-cellular compartment is particularly important for the understanding of coffee responses to abiotic/biotic stress. This article is part of a Special Issue entitled: Environmental and structural proteomics. Copyright © 2014 Elsevier B.V. All rights reserved.

Sonic anemometry measurements to determine airflow patterns in multi-tunnel greenhouse

Energy Technology Data Exchange (ETDEWEB)

Lopez, A.; Valera, D. L.; Molina-aiz, F. D.; Pena, A.

2012-11-01

The present work describes a methodology for studying natural ventilation in Mediterranean greenhouses using sonic anemometry. The experimental work took place in the three-span greenhouse located at the agricultural research farm belonging to the University of Almeria. This methodology has allowed us to obtain patterns of natural ventilation of the experimental greenhouse under the most common wind regimes for this region. It has also enabled us to describe how the wind and thermal effects interact in the natural ventilation of the greenhouse, as well as to detect deficiencies in the ventilation of the greenhouse, caused by the barrier effect of the adjacent greenhouse (imply a mean reduction in air velocity close to the greenhouse when facing windward of 98% for u, 63% for u, and more importantly 88% for ux, the component of air velocity that is perpendicular to the side vent). Their knowledge allows us to improve the current control algorithms that manage the movement of the vents. In this work we make a series of proposals that could substantially improve the natural ventilation of the experimental greenhouse. For instance, install vents equipped with ailerons which guide the air inside, or with vents in which the screen is not placed directly over the side surface of the greenhouse. A different proposal is to prolong the opening of the side vents down to the soil, thus fomenting the entrance of air at crop level. (Author) 34 refs.

Water utilization of vegetables grown under plastic greenhouse conditions in Ankara using neutron probe technique

International Nuclear Information System (INIS)

Halitligil, M.B.; Kislal, H.; Sirin, H.; Sirin, C.; Kilicaslan, A.

2004-01-01

In order to find suitable varieties of tomato, pepper and cucumber for plastic greenhouse conditions in Ankara and ensure both higher yields and lower NO 3 leaching greenhouse experiments were conducted for three years. In the first year (2001) of the experiment four different varieties from each vegetable, namely, Tomato (Ecem F 1 , 9920 F 1 , 2116 F 1 and Yazg1 F 1 ), Cucumber (Hizir F 1 , Rapido, Hana, and Luna) and Pepper (1245 F 1 , 730 F 1 , Serademre 8 and 710 F 1 ) had been grown in the plastic greenhouse using drip irrigation-fertilization system. Yazg1 F 1 variety for tomato, Hizir F 1 variety for cucumber and Serademre 8 variety for pepper were chosen to be suitable varieties to grow in the plastic greenhouse conditions in Ankara. One access tube in each N 3 and N 0 treatment plots of tomato, cucumber and pepper in 2002 and 2003 experiments were installed for the soil moisture determinations at 30, 60 and 90 cm depths. Readings with the neutron probe were taken before planting and after harvest for the water consumption calculations using the water balance approach and the WUE was calculated on the basis of the ratio of dry matter weight to the amount of water consumed. Tensiometer and suction cups were installed at 15, 30, 45 and 60 cm depths only to N 1 , N 2 and N 3 treatments plots of each vegetable in 2002 and 2003. Tensiometer readings were taken just before irrigation. Also, soil solution samples from suction cups were taken at final harvest and NO 3 determinations were done with RQFLEX nitrate test strips. Significantly higher yields and WUE values were obtained when the same amount of N fertilizer is applied through fertigation compared to the treatment where N fertilizer applied to the soil then drip irrigated. The nitrate concentrations of the soil solution increased as the N rates increased and no NO 3 had been found in the soil solution taken from 75 cm soil depth, indicating that no leaching of N fertilizer occurred beyond 75 cm soil depth

Water utilization of vegetables grown under plastic greenhouse conditions in Ankara using neutron probe technique

International Nuclear Information System (INIS)

Halitligil, M.B.; Kislal, H.; Sirin, H.; Sirin, C.; Kilicaslan, A.

2004-01-01

Full text: In order to find suitable varieties of tomato, pepper and cucumber for plastic greenhouse conditions in Ankara and ensure both higher yields and lower NO 3 leaching greenhouse experiments were conducted for three years. In the first year (2001) of the experiment four different varieties from each vegetable, namely, Tomato (Ecem F 1 , 9920 F 1 , 2116 F 1 and Yazg1 F 1 ), Cucumber (Hizir F 1 , Rapido, Hana, and Luna) and Pepper (1245 F 1 , 730 F 1 , Serademre 8 and 710 F 1 ) had been grown in the plastic greenhouse using drip irrigation-fertiligation system. Yazg1 F 1 variety for tomato, Hizir F 1 variety for cucumber and Serademre 8 variety for pepper were chosen to be suitable varieties to grow in the plastic greenhouse conditions in Ankara. One access tube in each N 3 and N 0 treatment plots of tomato, cucumber and pepper in 2002 and 2003 experiments were installed for the soil moisture determinations at 30, 60 and 90 cm depths. Readings with the neutron probe were taken before planting and after harvest for the water consumption calculations using the water balance approach and the WUE was calculated on the basis of the ratio of dry matter weight to the amount of water consumed. Tensiometer and suction cups were installed at 15, 30, 45 and 60 cm depths only to N 1 , N 2 and N 3 treatments plots of each vegetable in 2002 and 2003. Tensiometer readings were taken just before irrigation. Also, soil solution samples from suction cups were taken at final harvest and NO 3 determinations were done with RQFLEX nitrate test strips. Significantly higher yields and WUE values were obtained when the same amount of N fertilizer is applied through fertigation compared to the treatment where N fertilizer applied to the soil then drip irrigated. The nitrate concentrations of the soil solution increased as the N rates increased and no NO 3 had been found in the soil solution taken from 75 cm soil depth, indicating that no leaching of N fertilizer occurred beyond 75 cm

[Cytoembryologic studies of super dwarf wheat grown in "Svet" greenhouse in the ground-based experiments

Science.gov (United States)

Levinskikh, M. A.; Veselova, T. D.; Il'ina, G. M.; Dzhalilova, Kh Kh; Sychev, V. N.; Derendiaeva, T. A.; Salisbury, F.; Cambell, W.; Bubenheim, D.; Campbell, W. (Principal Investigator)

1998-01-01

The Project of scientific programs MIR/SHUTTLE and MIR/NASA was allowed for studying the productional, cytoembryological, morphological, biomechanical and other characteristics of superclub wheat on cultivation in the Svet greenhouse on-board orbital complex. This work was aimed at studying the duration of the complete cycle of ontogenesis of wheat and its individual stages, the peculiarities of forming the reproductive organs, processes, fertilization and formation of the seed production while cultivating in the Svet greenhouse under terrestrial conditions. Superclub wheat has been the object of experimentation. On cultivation of superclub wheat in the Svet greenhouse at designated conditions it was found that the cycle duration "from seed to seed" was 90-97 days. The number of granules in the wheat-ears studied was quite low and ranged from 15 to 30%. Performed studies with applying the light microscopy have indicated that in superclub wheat the embryological processes occur in compliance with those regularities which are described for the other forms of soft wheat.

Water deficit effects on maize yields modeled under current and greenhouse climates

International Nuclear Information System (INIS)

Muchow, R.C.; Sinclair, T.R.

1991-01-01

The availability of water imposes one of the major limits on rainfed maize (Zea mays L.) productivity. This analysis was undertaken in an attempt to quantify the effects of limited water on maize growth and yield by extending a simple, mechanistic model in which temperature regulates crop development and intercepted solar radiation is used to calculate crop biomass accumulation. A soil water budget was incorporated into the model by accounting for inputs from rainfall and irrigation, and water use by soil evaporation and crop transpiration. The response functions of leaf area development and crop gas exchange to the soil water budget were developed from experimental studies. The model was used to interpret a range of field experiments using observed daily values of temperature, solar radiation, and rainfall or irrigation, where water deficits of varying durations developed at different stages of growth. The relative simplicity of the model and its robustness in simulating maize yields under a range of water-availability conditions allows the model to be readily used for studies of crop performance under alternate conditions. One such study, presented here, was a yield assessment for rainfed maize under possible greenhouse climates where temperature and atmospheric CO 2 concentration were increased. An increase in temperature combined with decreased rainfall lowered grain yield, although the increase in crop water use efficiency associated with elevated CO 2 concentration ameliorated the response to the greenhouse climate. Grain yields for the greenhouse climates as compared to current conditions increased, or decreased only slightly, except when the greenhouse climate was assumed to result in severly decreased rainfall

Some considerations on the utilization of thermal drainage for greenhouse heating by means of indirect heat exchange system

International Nuclear Information System (INIS)

Yamamoto, Yujiro; Aoki, Kiyoshi; Okano, Toshiaki

1976-01-01

The cost of maintaining the desirable temperature in winter is the principal element in the production of vegetables by greenhouse culture. Therefore very low heating cost and profitable operation are possible if the warm water from a condenser in a power plant is available as the heat source for greenhouse heating. In order to investigate the possibility of utilizing warm water discharge as the heat source for greenhouse heating, experiment was carried out with a miniature greenhouse equipped with the indirect heat exchanger with PVC pipes. The results obtained are summarized as follows. Under the conditions of the warm water discharge of 25 deg C and outside air temperature of -5 deg C, the average temperature and relative humidity in the greenhouse were about 10 deg C and 80%, respectively. From the experimentally obtained relationship between the heat transfer coefficient on the PVC pipe surfaces and the velocity of air passing through the pipes, the heat transfer coefficient at 8 m/sec air velocity was three times as much as that at 2 m/sec. From the theoretically obtained formula for calculating the number of pipes required for a greenhouse, it was determined that 72 PVC pipes of 10 cm diameter and 23 m long were required for a 23 x 25 m greenhouse to maintain 12 deg C inside under the before-described conditions. (Kako, I.)

Degradation of three fungicides following application on strawberry and a risk assessment of their toxicity under greenhouse conditions.

Science.gov (United States)

Sun, Caixia; Cang, Tao; Wang, Zhiwei; Wang, Xinquan; Yu, Ruixian; Wang, Qiang; Zhao, Xueping

2015-05-01

The health risk to humans of pesticide application on minor crops, such as strawberry, requires quantification. Here, the dissipation and residual levels of three fungicides (pyraclostrobin, myclobutanil, and difenoconazole) were studied for strawberry under greenhouse conditions using high-performance liquid chromatography (HPLC)-tandem mass spectrometry after Quick, Easy, Cheap, Effective, Rugged, and Safe extraction. This method was validated using blank samples, with all mean recoveries of these three fungicides exceeding 80%. The residues of all three fungicides dissipated following first-order kinetics. The half-lives of pyraclostrobin, myclobutanil, and difenoconazole were 1.69, 3.30, and 3.65 days following one time application and 1.73, 5.78, and 6.30 days following two times applications, respectively. Fungicide residue was determined by comparing the estimated daily intake of the three fungicides against the acceptable daily intake. The results indicate that the potential health risk of the three fungicides was not significant in strawberry when following good agricultural practices (GAP) under greenhouse conditions.

Assessment of energy consumption in organic tomato greenhouse production - a case study

NARCIS (Netherlands)

Baptista, F.J.; Murcho, D.; Silva, L.; Stanghellini, C.; Montero, J.I.; Kempkes, F.; Munoz, P.; Gilli, Celine; Giuffrida, F.; Stepowska, Agnieszka

2017-01-01

Greenhouse production has increased over the last decades in the Mediterranean region. Greenhouses allow protecting crops from adverse climate conditions, creating microclimate conditions appropriate for obtaining high production with high quality all over the year. However, greenhouse production is

Application of Endophytic Pseudomonas fluorescens and a Bacterial Consortium to Brassica napus Can Increase Plant Height and Biomass under Greenhouse and Field Conditions

Directory of Open Access Journals (Sweden)

Richard D. Lally

2017-12-01

Full Text Available Plant associated bacteria with plant growth promotion (PGP properties have been proposed for use as environmentally friendly biofertilizers for sustainable agriculture; however, analysis of their efficacy in the field is often limited. In this study, greenhouse and field trials were carried out using individual endophytic Pseudomonas fluorescens strains, the well characterized rhizospheric P. fluorescens F113 and an endophytic microbial consortium of 10 different strains. These bacteria had been previously characterized with respect to their PGP properties in vitro and had been shown to harbor a range of traits associated with PGP including siderophore production, 1-aminocyclopropane-1-carboxylic acid (ACC deaminase activity, and inorganic phosphate solubilization. In greenhouse experiments individual strains tagged with gfp and Kmr were applied to Brassica napus as a seed coat and were shown to effectively colonize the rhizosphere and root of B. napus and in addition they demonstrated a significant increase in plant biomass compared with the non-inoculated control. In the field experiment, the bacteria (individual and consortium were spray inoculated to winter oilseed rape B. napus var. Compass which was grown under standard North Western European agronomic conditions. Analysis of the data provides evidence that the application of the live bacterial biofertilizers can enhance aspects of crop development in B. napus at field scale. The field data demonstrated statistically significant increases in crop height, stem/leaf, and pod biomass, particularly, in the case of the consortium inoculated treatment. However, although seed and oil yield were increased in the field in response to inoculation, these data were not statistically significant under the experimental conditions tested. Future field trials will investigate the effectiveness of the inoculants under different agronomic conditions.

Experimental investigation on a coupled solar still under desert climatic conditions

International Nuclear Information System (INIS)

Boukar, M.; Harmim, A.

2000-01-01

Distillation of water is energy intensive, and the use of solar energy for this purpose has been quite well developed and applied in many places. The performance of a simple basin greenhouse-type solar still coupled to a flat plate collector is experimentally investigated. The Saharan sites of Algeria enjoys bright sunshine and dry weather during most part of year. The objective of the work is to improve the performances of a simple single basin solar still, we test the distillation system in winter, under desert climatic conditions, to improve the quality and increase the quantity of distilled water, by using a solar collector for increasing the brine temperature, enhancing the evaporation process of a simple solar still and improving distillate collection process. Experiments have been conducted in Adrar, Algerian desert town (27 degree 18' N, latitude, 0 degree 17' W longitude). The daily still productivity in winter period varies from 4.5 l/m 2 /day to 5.3 l/m 2 /day with variation of water level from 1.5 cm to 3.5 cm. (Author)

Greenhouse climate : from physical processes to a dynamic model

OpenAIRE

Bot, G.P.A.

1983-01-01

In this thesis greenhouse climate has been studied as the set of environmental conditions in a greenhouse in so far as they affect crop growth and development. In chapter 2 this set has been defined in terms of temperatures and vapour pressures. Moreover we have indicated which physical processes co-operate in the greenhouse. So the dependency of the greenhouse climate on the outside weather, the physical properties of the greenhouse construction and the way ventilation and heating is perform...

Failure of supplementary ultraviolet radiation to enhance flower color under greenhouse conditions

Energy Technology Data Exchange (ETDEWEB)

Klein, R. M. [University of Vermont, Burlington, VT (United States)

1990-03-15

In order to determine whether the concentration of floral petal anthocyanin pigments could be increased, ultraviolet radiations in the UV-A and UV-B wavelength bands were presented to a variety of flowering plants to partly restore those wavelengths filtered out by greenhouse glass. In no tested plant did the supplementary ultraviolet radiation enhance floral anthocyanin content. Supplementary UV radiation has no economic value in greenhouse production of flowering plants. (author)

Morphophysiological and productive indicators of the pepper planted in the greenhouse and in the open field in the conditions of the Ecuadorian Amazon

Directory of Open Access Journals (Sweden)

Reinaldo Demesio Alemán Pérez

2018-01-01

Full Text Available The Ecuadorian Amazon is the poorest region of Ecuador, particularly the province of Pastaza. The production of vegetables in the region is very limited and only established in the greenhouse. The pepper (Capsicum annuum L. is a horticultural product very demanded, however, there is a criterion that cannot be grown in the area. Therefore, since 2014, the Center for Research, Posgraduate and Conservation of Amazonian Biodiversity (CIPCA, belonging to Universidad Estatal Amazonica initiated a research program to evaluate the adaptation of different horticultural species plants to conditions in the region, in order to contribute to food sustainability. The study consisted of determining the behavior of the Nathalie hybrid pepper crop, planted in greenhouse and open field conditions, for which a randomized block design was used. Productions, physiological and morphological indicators of the crop were evaluated and the results obtained were made a statistical comparison of means. The results suggest that better morphophysiological indicators are obtained when it was sown in the greenhouse, with height of 136 cm and a foliar area of 0.95 m2. However, the best productive and agricultural performance indicators were obtained outside the greenhouse, with 9 fruits per plant, with an average fruit weight of 975.80 g and an average yield of 6.42 kg m-2. This indicates the convenience of establishing this crop in the Ecuadorian Amazon without sow in the greenhouse.

Buying greenhouse insurance

International Nuclear Information System (INIS)

Manne, A.S.; Richels, R.G.

1992-01-01

A growing concern that the increasing accumulation of greenhouse gases will lead to undesirable changes in global climate has resulted in proposals, both in the United States and internationally, to set physical targets for reducing greenhouse gas emissions. But what will these proposals cost? This book outlines a way to think about greenhouse-effect decisions under uncertainty. It describes an insightful model for determining the economic costs of limiting CO 2 emissions produced by burning fossil fuels and provides a solid analytical base for rethinking public policy on the far-reaching issue of global warming. It presents region-by-region estimates of the costs that would underlie an international agreement. Using a computer model known as Global 2100, they analyze the economic impacts of limiting CO 2 emissions under alternative supply and conservation scenarios. The results clearly indicate that a reduction in emissions is not the sole policy response to potential climate change. Following a summary of the greenhouse effect, its likely causes, and possible consequences, this book takes up issues that concern the public at large. They provide an overview of Global 2100, look at how the U.S. energy sector is likely to evolve under business-as-usual conditions and under carbon constraints, and describe the concept of greenhouse insurance. They consider possible global agreements, including an estimate of benefits that might result from trading in an international market in emission rights. They conclude with a technical description directed toward modeling specialists

Thermal modeling and parametric studies of a greenhouse fish pond in the Central Himalayan Region

International Nuclear Information System (INIS)

Sarkar, Bikash; Tiwari, G.N.

2006-01-01

This study describes the thermal modeling and its validation of greenhouse fish pond systems. Numerical computations have been performed for a typical day in the month of June, 2005, for the climatic condition of Champawat in the Central Himalayan Region. The energy balance equations have been written considering the effects of conduction, convection, radiation, evaporation and ventilation. The governing equations are numerically solved with Matlab 7.0 software to predict the water temperature. A parametric study has also been performed to find the effects of various parameters, namely the number of air changes per hour, the transmissivity (τ) and the isothermal mass and height of the greenhouse. It is observed that there is no significant effect in the parametric studies on water temperature due to the larger isothermal mass. The model has been validated with experimental data. On an average, the even span passive greenhouse fish pond can increase the inside temperature 4.14 deg. C higher than the temperature of an outdoor pond. Statistical analysis shows that the predicted and experimental values of water temperature exhibited fair agreement with a coefficient of correlation r = 0.90 and root mean square percent deviation e = 1.67%

The greenhouse effect of planetary atmospheres

International Nuclear Information System (INIS)

Kondratyev, K.Ya.; Moskalenko, N.I.

1980-01-01

The greenhouse effect of the atmosphere is the main factor of possible climate changes of anthropogenic origin. The growing pollution of the atmosphere leads to an increase of the concentration of various gaseous components. Of great importance is also the consideration of the aerosols. All the gaseous components, as well as aerosols, have the absorption bands in the IR spectral range. The traditional attention to the problem of the CO 2 contribution to the greenhouse effect has somewhat overshadowed the significance of the different components. The data characterizing the significance of the different components of the greenhouse effect are considered. The results of studying the absorption spectra of methane, nitrous oxides, sulphuric gas, ammonia, nitric-acid vapours and other components are discussed. The assessments of their contribution to the greenhouse effect are given. The important role of the small-size fraction of the atmospheric aerosols as a factor of the greenhouse effect is discussed. Both the analysis of the causes of the Earth's climate variability and the relevant investigation of the atmospheric greenhouse effect determine the expediency of analysing the conditions of the greenhouse effect formation on other planets. Laboratory studies of the IR absorption spectra of synthetic CO 2 atmospheres were carried out. Some results from these studies are discussed. (author)

Calculation of NIR effect on greenhouse climate in various conditions

NARCIS (Netherlands)

Kempkes, F.L.K.; Hemming, S.

2012-01-01

In Northern regions of Europe glass is mainly used as greenhouse covering material whereas in Southern regions plastic films are commonly used. The develop-ment of covering material optical properties focuses on high light transmission, reduction of heating energy losses (higher latitudes) and

Design, implementation and evalution of a central unit for controlling climatic conditions in the greenhouse

OpenAIRE

Gh. Zarei; A. Azizi

2016-01-01

In greenhouse culture, in addition to increasing the quantity and quality of crop production in comparison with traditional methods, the agricultural inputs are saved, too. Recently, using new methods, designs and materials, and higher automation in greenhouses, better management has become possible for enhancing yield and improving the quality of greenhouse crops. The constructed and evaluated central controller unit (CCU) is a central controller system and computerized monitoring unit for g...

Performance analysis of greenhouse dryer by using insulated north-wall under natural convection mode

Directory of Open Access Journals (Sweden)

Prashant Singh Chauhan

2016-11-01

Full Text Available A prototype north wall insulated greenhouse dryer has been fabricated and tested in no-load conditions under natural convection mode. Experimentation has been conducted in two different cases. Case-I is when solar collector placed inside the dryer and Case-II is North wall insulated greenhouse dryer without solar collector. Coefficient of performance, heat utilisation factor, convective heat transfer coefficient and coefficient of diffusivity have been evaluated in thermal performance analysis. The difference of the highest convective heat transfer coefficient of both cases is 29.094W/m2°C which is showing the effectiveness of insulated north wall and solar collector. The maximum coefficient of diffusivity (0.0827 was achieved during the third day of experiment in Case-II. The inside room temperature of wall insulated greenhouse dryer for Case-I is 4.11%, 5.08 % and 11.61 % higher than the Case-II during the day 1, day 2 and day 3 respectively. This result is also showing the effectiveness of solar collector and insulated north wall. The highest heat utilisation factor (0.616 is obtained during the second day for Case-I while for Case-II it is 0.769 during the third day of experimentation. Maximum coefficient of performance achieved is 0.892 during the third day of the experiment for Case-I whereas 0.953 is obtained on the first day of experimentation for Case-II.

Micropropagation, Acclimatization, and Greenhouse Culture of Veratrum californicum.

Science.gov (United States)

White, Sarah A; Adelberg, Jeffrey; Naylor-Adelberg, Jacqueline; Mann, David A; Song, Ju Yeon; Sun, Youping

2016-01-01

Micropropagation and production of Veratrum californicum is most successful when using a premixed Murishage and Skoog basal medium with vitamins and a 5-week subculture cycle at 16 °C for multiplication. These culture conditions provide the best percent survival after acclimatization in the greenhouse. However, clone response to temperature and light quality within culture conditions varies. Micropropagated plants have mass and morphology similar to 2- or 3-year-old seedlings. Acclimatized plantlets can then be grown in the greenhouse using sub-irrigation (ebb and flood) to maintain substrate volumetric water content > 44 %. Growth cycle in the greenhouse must be about 100 days, followed by dormancy for 5 months at 5 °C.

Uptake of plutonium, americium, curium, and neptunium in plants cultivated under greenhouse conditions

International Nuclear Information System (INIS)

Pimpl, M.; Schmidt, W.

1984-01-01

The root-uptake of Np, Pu, Am, and Cm from three different artificially contaminated soils in grass, maize, spring wheat, and potatoes was investigated under greenhouse conditions in pots filled with 9 kg contaminated soil and in lysimeters with a surface area of 0,5 m 2 containing the soils in undisturbed profils up to a depth of 80 cm. Only the plough layer of 30 cm was contaminated with Np, Pu, Am, and Cm. Crop cultivation was done corresponding to usual practice in agriculture. Results of the 1st vegetation period are represented. Transfer factors obtained deviate considerably from those which are recommended for the estimation of long-term exposure of man in the Federal Republic of Germany. (orig.)

Simple greenhouse climate model as a design tool for greenhouses in tropical lowland

NARCIS (Netherlands)

Impron, I.; Hemming-Hoffmann, S.; Bot, G.P.A.

2007-01-01

Six prototypes plastic greenhouses were built in the tropical lowlands of Indonesia. The geometrical dimensions were designed using computational fluid dynamics (CFD) by taking local climate parameters as static reference boundary conditions. It is necessary to evaluate the climate dynamics inside

Greenhouses and their humanizing synergies

Science.gov (United States)

Haeuplik-Meusburger, Sandra; Paterson, Carrie; Schubert, Daniel; Zabel, Paul

2014-03-01

Greenhouses in space will require advanced technical systems of automatic watering, soil-less cultivation, artificial lighting, and computerized observation of plants. Functions discussed for plants in space habitats include physical/health requirements and human psychology, social cohesion, as well as the complex sensorial benefits of plants for humans. The authors consider the role of plants in long-term space missions historically since 1971 (Salyut 1) and propose a set of priorities to be considered within the design requirements for greenhouses and constructed environments given a range of benefits associated with plant-human relationships. They cite recent research into the use of greenhouses in extreme environments to reveal the relative importance of greenhouses for people living in isolated locations. Additionally, they put forward hypotheses about where greenhouses might factor into several strata of human health. In a recent design-in-use study of astronauts' experiences in space habitats discussed in Architecture for Astronauts (Springer Press 2011) it was found that besides the basic advantages for life support there are clearly additional "side benefits" for habitability and physical wellbeing, and thus long-term mission success. The authors have composed several key theses regarding the need to promote plant-human relationships in space, including areas where synergy and symbiosis occur. They cite new comprehensive research into the early US Space Program to reveal where programmatic requirements could be added to space architecture to increase the less quantifiable benefits to astronauts of art, recreation, and poetic engagement with their existential condition of estrangement from the planet. Specifically in terms of the technological requirements, the authors propose the integration of a new greenhouse subsystem component into space greenhouses—the Mobile Plant Cultivation Subsystem—a portable, personal greenhouse that can be integrated

Cooling of a polyethylene tunnel type greenhouse by means of a rock bed

Energy Technology Data Exchange (ETDEWEB)

Kurklu, Ahmet; Bilgin, Sefai [Akdeniz Univ., Dept. of Agricultural Mechanisation, Antalya (Turkey)

2004-10-01

An experiment was conducted to cool a 15 m{sup 2} ground area plastic-tunnel-type greenhouse by the use of a rock bed. An identical greenhouse with no rock bed was also erected for control purposes. Two rock-bed canals, each with the dimensions of 3 x l.25 x 0.75 m, were dug in the soil of the experimental greenhouse. After the canals were filled with the rocks and insulated, the top surface was covered by a soil layer of thickness enough for the root development depth of the plants. Air was pushed through the rock bed by a centrifugal fan with a 1100 m{sup 3}/h flow rate. Energy stored in the rock bed during the day was dumped outside the greenhouse at night using the cooler outside air. The results of the measurements showed that the rock-bed system maintained air temperature 14 deg C lower at maximum in the experimental greenhouse than the control one. The temperature difference seemed to increase with increasing solar radiation and outside air temperature. Relative humidity during the day remained at about 40% in the experimental greenhouse and was always higher than that in the control one. The coefficient of performance (COP) of the rock-bed system was higher than 3 in general, and it was observed that this value increased with decreasing rock-bed temperature. The average solar collection efficiency was 38%. The rock-bed system seems to have a significant potential for cooling applications in greenhouses. (Author)

Sonic anemometry to measure natural ventilation in greenhouses.

Science.gov (United States)

López, Alejandro; Valera, Diego Luis; Molina-Aiz, Francisco

2011-01-01

The present work has developed a methodology for studying natural ventilation in Mediterranean greenhouses by means of sonic anemometry. In addition, specific calculation programmes have been designed to enable processing and analysis of the data recorded during the experiments. Sonic anemometry allows us to study the direction of the airflow at all the greenhouse vents. Knowing through which vents the air enters and leaves the greenhouse enables us to establish the airflow pattern of the greenhouse under natural ventilation conditions. In the greenhouse analysed in this work for Poniente wind (from the southwest), a roof vent designed to open towards the North (leeward) could allow a positive interaction between the wind and stack effects, improving the ventilation capacity of the greenhouse. The cooling effect produced by the mass of turbulent air oscillating between inside and outside the greenhouse at the side vents was limited to 2% (for high wind speed, u(o) ≥ 4 m s(-1)) reaching 36.3% when wind speed was lower (u(o) = 2 m s(-1)).

EFECT OF THE INOCULATION OF Rhodococcus fascians AND Azospirillum halopraeferens IN GERMINATION OF PALO FIERRO (Olneya tesota A. Gray UNDER GREENHOUSE CONDITIONS

Directory of Open Access Journals (Sweden)

Edgar Omar Rueda Puente

2017-05-01

Full Text Available The growth-promoting bacteria in plants (BGPB are a group of different species of bacteria can increase plant growth and productivity. Which can benefit plants through their own bacterial metabolism (phosphate solubilizing, producing hormones or fixing nitrogen. At present, desertification is a growing phenomenon worldwide, afforestation is one of the common solutions to combat this problem. Trees for reforestation are initially grown in greenhouses or nurseries. Among numerous reforestation practices, there is an alternative that inoculation with PGPB. Is a forest species that is endemic Olneya tesota Sonoran Desert, which is in danger of extinction. The objective was to evaluate the effect of bacteria growth promoter in plants with Rhodococcuis fascians and Azospirillum halopraeferens on germination and emergence of Ironwood under four salt concentrations (0, 0.25, 0.5 and 0.75 M NaCl under greenhouse conditions. Were obtained ironwood seeds in the region of Santa Ana, Sonora. Under greenhouse conditions was evaluated emergence percentage, germination rate, height, plant root length, fresh and dry weight of plant, number of bacterial cells attached to the root system, fresh and dry weight of the root. The results indicate that the germination percentage and other variables evaluated decreased as salinity increases. However, these changed positively to inoculation with bacteria R. fascians and A. halopraeferens.

Greenhouse Gases

Science.gov (United States)

... Production of Hydrogen Use of Hydrogen Greenhouse Gases Basics | | Did you know? Without naturally occurring greenhouse gases, the earth would be too cold to support life as we know it. Without the greenhouse effect, ...

Thermal modeling of a greenhouse integrated to an aquifer coupled cavity flow heat exchanger system

Energy Technology Data Exchange (ETDEWEB)

Sethi, V.P. [Department of Mechanical Engineering, Punjab Agricultural University, Ludhiana 141 008, Punjab (India); Sharma, S.K. [Energy Research Centre, Panjab University, Chandigarh 160 017, Punjab (India)

2007-06-15

A thermal model is developed for heating and cooling of an agricultural greenhouse integrated with an aquifer coupled cavity flow heat exchanger system (ACCFHES). The ACCFHES works on the principal of utilizing deep aquifer water available at the ground surface through an irrigation tube well already installed in every agricultural field at constant year-round temperature of 24 C. The analysis is based on the energy balance equations for different components of the greenhouse. Using the derived analytical expressions, a computer program is developed in C{sup ++} for computing the hourly greenhouse plant and room air temperature for various design and climatic parameters. Experimental validation of the developed model is carried out using the measured plant and room air temperature data of the greenhouse (in which capsicum is grown) for the winter and summer conditions of the year 2004-2005 at Chandigarh (31 N and 78 E), Punjab, India. It is observed that the predicted and measured values are in close agreement. Greenhouse room air and plant temperature is maintained 6-7 K and 5-6 K below ambient, respectively for an extreme summer day and 7-8 K and 5-6 K above ambient, respectively for an extreme winter night. Finally, parametric studies are conducted to observe the effect of various operating parameters such as mass of the plant, area of the plant, mass flow rate of the circulating air and area of the ACCFHES on the greenhouse room air and plant temperature. (author)

Residential greenhouse

Energy Technology Data Exchange (ETDEWEB)

1985-02-01

The following report examines the technical and economic viability of residential greenhouse additions in Whitehorse, Yukon. The greenhouse was constructed using the south facing wall of an existing residence as a common wall. Total construction costs were $18,000, including labour. Annual fuel demand for the residence has been reduced by about 10 per cent for an annual saving of $425. In addition, produce to the value of $1,000 is grown annually in the greenhouse for domestic consumption and commercial resale. Typically the greenhouse operates for nine months each year. There is a net thermal loss during the months of November, December and January as a result of the large area of glazing. As well as supplementing the heating supply solar greenhouses can provide additional cash crops which can be used to offset the cost of construction. Humidity problems are minimal and can be dealt with by exhausting high humidity air. One system which has been considered for the greenhouse is to use a standard residential heat pump to remove excess moisture and to pump heat into the house. This would have a secondary benefit of excluding the need to circulate greenhouse air through the house. Thus any allergenic reactions to the greenhouse air would be prevented. 8 refs., 3 figs, 2 tabs.

Microclimate evaluation of a new design of insect-proof screens in a Mediterranean greenhouse

Directory of Open Access Journals (Sweden)

Alejandro Lopez-Martinez

2014-05-01

Full Text Available This work studies natural ventilation in a Mediterranean greenhouse, comparing a new experimental screen of 13×30 threads cm-2 (porosity 39.0% with a commercial control screen of 10×20 threads cm-2 (porosity 33.5%. In addition, both screens were tested in a wind tunnel to determine the discharge coefficients Cd of the greenhouse side and roof vents, which proved to be 0.16 for the commercial control screen and 0.18 for the experimental screen at both vents. These values represent a theoretical increase of 11% (Cd,φ-10×20 /Cd,φ-13×30 = 0.89 in the natural ventilation capacity of the greenhouse when the experimental screen is used. The greenhouse was divided into two separate sections allowing us to analyze natural ventilation in both sectors simultaneously. Air velocity was measured in the lateral and roof vents with two 3D and six 2D sonic anemometers. Using the commercial control screen there was an average reduction of 16% in ventilation rate, and an average increase of 0.5ºC in the average indoor air temperature, compared to the experimental screen. In addition, the ventilation efficiency ηT was higher with the experimental screen (mean value of 0.9 than with the control (mean value 0.6. We have designed an experimental insect-proof screen (13×30 threads cm-2 with smaller thread diameter, higher thread density, smaller pore size and higher porosity than are used in most commercial meshes. All of these factors promote natural ventilation and improve the greenhouse microclimate.

Temperature Simulation of Greenhouse with CFD Methods and Optimal Sensor Placement

Directory of Open Access Journals (Sweden)

Yanzheng Liu

2014-03-01

Full Text Available The accuracy of information monitoring is significant to increase the effect of Greenhouse Environment Control. In this paper, by taking simulation for the temperature field in the greenhouse as an example, the CFD (Computational Fluid Dynamics simulation model for measuring the microclimate environment of greenhouse with the principle of thermal environment formation was established, and the temperature distributions under the condition of mechanical ventilation was also simulated. The results showed that the CFD model and its solution simulated for greenhouse thermal environment could describe the changing process of temperature environment within the greenhouse; the most suitable turbulent simulation model was the standard k?? model. Under the condition of mechanical ventilation, the average deviation between the simulated value and the measured value was 0.6, which was 4.5 percent of the measured value. The distribution of temperature filed had obvious layering structures, and the temperature in the greenhouse model decreased gradually from the periphery to the center. Based on these results, the sensor number and the optimal sensor placement were determined with CFD simulation method.

ARBUSCULAR MYCORRHIZAL FUNGI INCREASED EARLY GROWTH OF GAHARU WOOD OF Aquilaria malaccencsis and A. crasna UNDER GREENHOUSE CONDITIONS

Directory of Open Access Journals (Sweden)

Maman Turjaman

2006-07-01

Full Text Available Gaharu wood stand has an important source of profits to the forest community in South and Southeast Asia tropical forest countries, but Aquilaria species have reduced in number and turn out to be endangered due to overexploitation.   Today,   the planting stocks of   Aquilaria species are not sufficient to sustain the yield of gaharu wood and promote forest conservation.  The objective of this study was to determine   the effect of   five arbuscular mycorrhizal (AM fungi: Entrophospora sp., Gigaspora decipiens, Glomus clarum, Glomus sp. ZEA, and Glomus sp. ACA, on the early growth of  Aquilaria malaccensis and A. crasna under greenhouse conditions. The seedlings of  Aquilaria spp. were inoculated with Entrophospora sp., Gi. decipiens, Glomus clarum, Glomus sp. ZEA, Glomus sp. ACA and uninoculated (control under greenhouse conditions. Then, percentage AM colonization, plant growth, survival rate and nitrogen (N and phosphorus (P content and mycorrhizal dependence (MD were measured. The percentage AM colonization of A. malaccensis and A. crasna ranged from 83 to 97% and from 63 to 78%, respectively. Colonization by five AM fungi increased plant height, diameter, and shoot and root dry weights. N and P content of  the seedlings were also increased by AM colonization. Survival rates were higher in the AM-colonized seedlings at 180 days after transplantation than those in the control seedlings. The MD of Aquilaria species was higher than 55 %. The results suggested that AM fungi can be inoculated`to Aquilaria species under nursery conditions to obtain vigorous seedlings, and the field experiment is underway to clarify the role of AM fungi under field conditions.

Occurrence, characterization and management of fruit rot of immature cucumber fruits under arid greenhouse conditions

Directory of Open Access Journals (Sweden)

ABDULLAH M AL-SADI

2012-01-01

Full Text Available A study was undertaken to characterize and manage pathogens associated with fruit rot of immature cucumber fruits in greenhouses in Oman. A survey over 5 growing seasons from 2008 to 2010 in 99 different greenhouses in Oman showed that the disease is prevalent in 91 (92% greenhouses and results in losses of 10 to 60% (avg. 33% of immature fruits per plant. Incidence of the disease was not found to be affected by growing seasons, which could be attributed to the limited fluctuations in ambient temperatures in greenhouses. Isolations from diseased cucumber fruits yielded Alternaria alternata (isolation frequency = 52%, Fusarium equiseti (40%, Cladosporium tenuissium (27%, Botrytis cinerea (6%, Fusarium solani (6%, Corynespora cassiicola (3%, Aspergillus spp. (2%, Curvularia sp. (1% and Bipolaris sp. (1%. With the exception of Curvularia and Bipolaris species, all other fungi were pathogenic on cucumber fruits, with Fusarium equiseti being the most aggressive, followed by Corynespora cassiicola, Botrytis cinerea and Alternaria alternata. Cladosporium and Aspergillus spp. were found to be weakly pathogenic. Comparing the efficacy of foliar and soil applications of carbendazim fungicide on fruit rot of cucumber showed that foliar applications significantly reduced fruit rot and increased cucumber yield when compared to soil application or to control (P < 0.01. This appears to be the first report of the association of Corynespora cassiicola and Fusarium equiseti with fruit rot of immature greenhouse cucumbers. This is also the first report in Oman for the association of Cladosporium tenuissimum with fruit rot of immature cucumbers. Findings are discussed in terms of factors affecting disease control in greenhouses using carbendazim.

Greenhouse climate : from physical processes to a dynamic model

NARCIS (Netherlands)

Bot, G.P.A.

1983-01-01

In this thesis greenhouse climate has been studied as the set of environmental conditions in a greenhouse in so far as they affect crop growth and development. In chapter 2 this set has been defined in terms of temperatures and vapour pressures. Moreover we have indicated which physical processes

Experimental Investigation of a Solar Greenhouse Heating System Equipped with a Parabolic Trough Solar Concentrator and a Double-Purpose Flat Plate Solar Collector

Directory of Open Access Journals (Sweden)

M Jafari

2017-10-01

Full Text Available Introduction Greenhouses provide a suitable environment in which all the parameters required for growing the plants can be controlled throughout the year. Greenhouse heating is one of the most important issues in productivity of a greenhouse. In many countries, heating costs in the greenhouses are very high, having almost 60-80% of the total production costs. In recent years, several studies have attempted to reduce the heating costs of the greenhouses by applying more energy efficient equipment and using the renewable energy sources as alternatives or supplementary to the fossil fuels. In the present study a novel solar greenhouse heating system equipped with a parabolic trough solar concentrator (PTC and a flat-plate solar collector has been developed. Therefore, the aim of this paper is to investigate the performance of the proposed heating system at different working conditions. Materials and Methods The presented solar greenhouse heating system was comprised of a parabolic trough solar concentrator (PTC, a heat storage tank, a pump and a flat plate solar collector. The PTC was constructed from a polished stainless steel sheet (as the reflector and a vacuum tube receiver. The PTC was connected to the tank by using insulated tubes and a water pump was utilized to circulate the working fluid trough the PTC and the heat exchanger installed between walls of the tank. The uncovered solar collector was located inside the greenhouse. During the sunshine time, a fraction of the total solar radiation received inside the greenhouse is absorbed by the solar collector. This rises the temperature of the working fluid inside the collector which led to density reduction and natural flow of the fluid. In other words, the collector works as a natural flow flat plate solar collector during the sunshine time. At night, when the greenhouse temperature is lower than tank temperature, the fluid flows in a reverse direction through the solar collector and the

Comparison on the heat requirements of a four-span greenhouse with a melting snow system and a single-span greenhouse

International Nuclear Information System (INIS)

Furuno, S.; Sase, S.; Ishii, M.

2004-01-01

The heat requirements were measured and compared between a four-span greenhouse with a melting snow system and a typical single-span greenhouse with no melting snow system. Generally, single-span greenhouses require no melting snow system because snow drops off naturally from the roofs by gravity. The results for the four-span greenhouse showed that the provided heat by a heater for melting snow increased with an increase in snowfall, and there was a high correlation between them. The heat requirement per unit floor area of the four-span greenhouse was slightly less than that of the single-span greenhouse. This suggests that the decrease in heat requirement for internal air because of the larger floor/surface area ratio of the four-span greenhouse was more than the increase in heat requirement for melting snow. The measured heat requirement of the four-span greenhouse with the melting snow system was equal to the estimated heat load based on a common calculation procedure. On the other hand, that of the single-span greenhouse was slightly smaller than the estimated heat load. These suggest that the estimated heat load based on the common calculation procedure was slightly overestimated and larger than the actual heat requirement excluding the heat for the melting snow in snowy area. This is likely due to the fact that the parameters in the common calculation procedure were determined under the condition of larger net radiation than that in snowy area

International policies to address the greenhouse effect. Encouraging developing country participation in global greenhouse control strategies

International Nuclear Information System (INIS)

Gupta, J.; Hischenmoller, M.; Vellinga, P.; Van der Wurff, R.; Junne, G.

1995-01-01

The conditions under which developing country governments are likely to feel motivated to take real action in addressing the greenhouse gas problem and the international mechanisms that are likely to succeed are briefly outlined

Stabilising the global greenhouse. A simulation model

International Nuclear Information System (INIS)

Michaelis, P.

1993-01-01

This paper investigates the economic implications of a comprehensive approach to greenhouse policies that strives to stabilise the atmospheric concentration of greenhouse gases at an ecolocially determined threshold level. In a theoretical optimisation model conditions for an efficient allocation of abatement effort among pollutants and over time are derived. The model is empirically specified and adapted to a dynamic Gams-algorithm. By various simulation runs for the period of 1990 to 2110, the economics of greenhouse gas accumulation are explored. In particular, the long-run cost associated with the above stabilisation target are evaluated for three different policy scenarios: i) A comprehensive approach that covers all major greenhouse gases simultaneously, ii) a piecemeal approach that is limited to reducing CO 2 emissions, and iii) a ten-year moratorium that postpones abatement effort until new scientific evidence on the greenhouse effect will become available. Comparing the simulation results suggests that a piecemeal approach would considerably increase total cost, whereas a ten-year moratorium might be reasonable even if the probability of 'good news' is comparatively small. (orig.)

Performance of modified greenhouse dryer with thermal energy storage

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Om Prakash

2016-11-01

Full Text Available In this attempt, the main goal is to do annual performance, environomical analysis, energy analysis and exergy analysis of the modified greenhouse dryer (MGD operating under active mode (AM and passive mode (PM. Thermal storage is being applied on the ground of MGD. It is applied in three different ways namely barren floor, floor covered with black PVC sheet (PVC and Black Coated. Experimental study of dryers in no-load conditions reveals that floor covered with a black PVC sheet is more conducive for drying purpose than other floors. The MGD under AM is found to be more effective as compared to PM for tomato and capsicum, which are high moisture content crops. For medium moisture content crop (potato chips, both dryers show relatively similar drying performance. Crops dried inside the greenhouse dryer are found to be more nutrient than open sun dried crops. The payback period of the modified greenhouse dryer under passive mode is found to be 1.11 years. However, for the active mode of the modified greenhouse dryer is only 1.89 years. The embodied energy of the passive mode of the dryer is a 480.277 kWh and 628.73 kWh for the active mode of the dryer. The CO2 emissions per annum for passive and active mode greenhouse dryers are found to be 13.45 kg and 17.6 kg respectively. The energy payback time, carbon mitigation and carbon credit have been calculated based type of crop dried. The range of exergy efficiency is 29%–86% in MGD under PM and 30%–78% in the MGD under AM. The variation of Heat utilization factor (HUF for MGD under PM is 0.12–0.38 and 0.26–0.53 for MGD under AM. The range of co-efficient of performances (COP for MGD under PM is 0.55–0.87 and 0.58–0.73 for MGD under AM.

Thermal modeling of the forced convection Sandwich Greenhouse drying system for rubber sheets

International Nuclear Information System (INIS)

Tanwanichkul, B.; Thepa, S.; Rordprapat, W.

2013-01-01

Highlights: • Sandwich Greenhouse is designed for better quality and efficiency of rubber sheet drying. • Thermal models are developed to predict the convection heat transfer coefficient. • The models are validated and show good agreement with the actual experimental data. • The proposed greenhouse can maintain 40–60 °C, suitable for rubber sheet drying. • This greenhouse can bring down the moisture content to 2.8% in fewer than 2 days. - Abstract: In this paper, a novel “Sandwich Greenhouse” for rubber sheet drying is proposed. Using solar energy as the only heat source instead of traditional smoke house that requires firewood, it eliminates shortcomings such as skilled labor monitoring requirement, possible fire hazard, and darken-color rubber sheets due to soot particle contamination. Our greenhouse is specially designed to retain solar energy within, while minimizing the heat loss to the outside environment. The mathematical models are developed to predict the convection mass transfer coefficient and to study the thermal behavior during the drying of rubber sheets under our proposed greenhouse design. Validated with experimental observations, the models show good agreement with the actual experimental data. The experiment demonstrates an effectiveness of our proposed Sandwich Greenhouse, as the temperature of the rubber sheet is 15 °C and 5 °C higher than the ambient temperature during the daytime and nighttime, respectively. As a result, the moisture content of the rubber sheets can decrease from 36.4% to 2.8% in fewer than 2 days

NF ISO 14064-2. Greenhouse gases. Part 2: specifications and guidance at the project level for quantification, monitoring and reporting of greenhouse gas emission reductions or removal enhancements

International Nuclear Information System (INIS)

2005-01-01

This document describes methodology for quantification, monitoring and reporting of activities intended to cause greenhouse gas emissions and reductions at projects level (activity modifying the conditions identified in a baseline scenario, intended to reduce emissions or to increase the removal of greenhouse gases). Thus it suggests a method for the declarations of inventory of projects greenhouse gases and provides support for the monitoring and the management of emissions. It provides terms and definitions, principles, the introduction to greenhouse gases projects and the requirements for greenhouse gas projects. (A.L.B.)

Desarrollo vegetativo de patrones cítricos cultivados en condiciones de invernadero bajo dos sistemas de riego Vegetative development of citrus seedlings cultivated at greenhouse conditions and submitted to two irrigations systems

Directory of Open Access Journals (Sweden)

Gilmar Schäfer

2006-08-01

Full Text Available En el presente estudio se evaluó el desarrollo vegetativo de patrones cítricos cultivados en invernadero bajo dos sistemas de riego. El experimento se realizó en la Estação Experimental Agronômica de la Universidade Federal do Rio Grande do Sul, ubicada en Eldorado do Sul, Rio Grande do Sul, Brasil, entre los meses de septiembre de 2003 y abril de 2004, totalizando 225 días de experimentación. El diseño experimental fue de parcelas subdivididas, en factorial 2 x 3, con 4 repeticiones de 22 contenedores cada. En las parcelas principales se evaluaron los sistemas de riego (microaspersión y capilaridad y en las subparcelas los patrones cítricos Poncirus trifoliata (L. Raf., citrangero 'C37' [P. trifoliata x Citrus sinensis (L. Osb. cv. Pêra] y lima 'Rangpur' (C. limonia Osb.. En condiciones de invernadero los patrones cítricos presentan un desarrollo vegetativo más rápido bajo riego por capilaridad respecto a la microaspersión. Los patrones cítricos evaluados presentan desarrollos vegetativos distintos, donde el citrangero 'C37' supera a los demás.The aim of the present work was to evaluate the vegetative development of citrus rootstock seedlings cultivated under greenhouse conditions with two irrigation systems. The experiment was conducted at the Estação Experimental Agronômica , Universidade Federal do Rio Grande do Sul, located in Eldorado do Sul, Rio Grande do Sul, Brazil, from September 2003 to April 2004, totalizing 225 days of experimentation. The experimental design was a split-plot, in a 2x3 factorial, with 4 replications of 22 pots each. In the main plot the irrigation systems was evaluated (micro sprinkler and capillarity and in the split-plot the citrus rootstocks [Trifoliate orange - Poncirus trifoliata (L. Raf., 'C37' citrange - P. trifoliata x Citrus sinensis (L. Osb. cv. Pêra and 'Rangpur' lime - C. limonia Osb.] were evaluated. The main result showed in conditions of greenhouse citrus rootstock seedlings

Extraction of Greenhouse Areas with Image Processing Methods in Karabuk Province

Science.gov (United States)

Yildirima, M. Z.; Ozcan, C.

2017-11-01

Greenhouses provide the environmental conditions to be controlled and regulated as desired while allowing agricultural products to be produced without being affected by external environmental conditions. High quality and a wide variety of agricultural products can be produced throughout the year. In addition, mapping and detection of these areas has great importance in terms of factors such as yield analysis, natural resource management and environmental impact. Various remote sensing techniques are currently available for extraction of greenhouse areas. These techniques are based on the automatic detection and interpretation of objects on remotely sensed images. In this study, greenhouse areas were determined from optical images obtained from Landsat. The study was carried out in the greenhouse areas in Karabuk province. The obtained results are presented with figures and tables.

Greenhouse cooling using a rainwater basin under the greenhouse

NARCIS (Netherlands)

Campen, J.B.

2006-01-01

The objective of the study was to determine the technical and economical aspects of additional applications for a rainwater basin installed under a greenhouse. The installation for cooling the greenhouse can be placed under the greenhouse. Part of the installation consists of a short-term heat store

A validated physical model of greenhouse climate.

NARCIS (Netherlands)

Bot, G.P.A.

1989-01-01

In the greenhouse model the momentaneous environmental crop growth factors are calculated as output, together with the physical behaviour of the crop. The boundary conditions for this model are the outside weather conditions; other inputs are the physical characteristics of the crop, of the

Gardening with Greenhouses

Science.gov (United States)

Keeler, Rusty

2010-01-01

Greenhouses come in all shapes, sizes, and price ranges: from simple hand-built plastic-covered frames to dazzling geodesic domes. Some child care centers install greenhouses as a part of their outdoor garden space. Other centers have incorporated a greenhouse into the building itself. Greenhouses provide a great opportunity for children to grow…

Greener greenhouses

Energy Technology Data Exchange (ETDEWEB)

Paksoy, Halime; Turgut, Bekir; Beyhan, Beyza; Dasgan, H. Yildiz; Evliya, Hunay; Abak, Kazim; Bozdag, Saziye

2010-09-15

Agricultural greenhouses are solution to the increased demand for higher production yields, facilitating off season cultivation and allowing the growth of certain varieties in areas where it was not possible earlier. Heating and/or cooling system, required to maintain the inside micro-climate in greenhouses mostly rely on fossil fuels and/or electricity. This paper aims to discuss the 'greener' solutions for heating and cooling systems of greenhouses based on different thermal energy storage concepts. Results from a greenhouse Aquifer Thermal Energy Storage (ATES) application in Turkey producing tomatoes with zero fossil fuels and up to 40% higher yield are presented.

Economic Sustainability of Italian Greenhouse Cherry Tomato

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Riccardo Testa

2014-11-01

Full Text Available Greenhouse tomato cultivation plays an important role in Sicily, being the primary production area in Italy, due to its favorable pedo-climatic conditions that permit extra-seasonal productions. In Sicily, more than half of greenhouse tomato production is derived from the Province of Ragusa on the southeastern coast, where especially cherry tomato typologies are cultivated. Over the last decade, the Ragusa Province has registered a decrease both in terms of greenhouse tomato area and harvested production due to several structural problems that would require restructuring of the tomato supply chain. Thus, since recognition of real costs and profitability of tomato growing is a vital issue, both from the perspective of the farm, as well as from that of the entrepreneur, the aim of this paper was to analyze the economic sustainability of Sicilian greenhouse cherry tomato cultivated in the Ragusa Province. In particular, an economic analysis on 30 representative farms was conducted in order to estimate production costs and profits of greenhouse cherry tomato. According to our results, the lack of commercial organization, which characterizes the small farms we surveyed, determines low contractual power for farmers and, consequently, low profitability.

Evaluation of Antagonistic of the some Fungal isolates on Golden Potato Cyst Nematode (Globoderarostochiensis in vitro and Greenhouse Conditions in Hamedan Province

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Kh. Abbasi

2017-12-01

Full Text Available Introduction:Potato (Solanumtuberosum is one of the most important crops used as a source of human food. Iran is the third-largest producer of potato in Asia, where the production rate in 2015 was estimated to be about 5 million tonnes. Potato producers inHamedan province produce 21.3% oftotal potato harvestedinIran. Golden potato cyst nematode, Globoderarostochiensis is the most destructive potato pathogen. As the chitin is a dominant composition in middle layer of the eggshell, using the chitinases produced as chitin-degrading enzymes in a wide range of fungiis a good strategy for biological control of the golden potato cyst nematode. We assessedthe ability of various antagonistic fungi to control Globoderarostochiensisunder in vitro and greenhouse conditions. Materials and Methods: Thirty four fungal isolates obtained from infected eggs of the potato cyst nematode, Globoderarostochiensisin potato fieldsofHamedan were evaluated in two chitin-agar and water-agar mediums under in vitro and greenhouse conditions.The ability of thechitinase enzyme production was assessedin chitin-agar medium with colloidal chitin as substrate, so the chitin was used as exclusive source of carbon.Colloidal chitin was prepared based onthe procedure of Seyedasliet al. (2004 with 10 g of powder chitin from practical-grade crab shell chitin (Sigma in 100 ml of 85% H3PO4. Water was added to the above mixtureand was filtered with cheese cloth. To completely remove acid, water addition and filtrationrepeated for several times. The produced unguent materialwas dried and powdered and then used as carbon source in the medium. 0.5 percent of colloidal chitin was added to the medium. Afterwards, a 5 mm disk from the edges of 5days old was placed in the center of Petridish and all of them were kept for 5 days at 25º C. Chitinase detection medium (chitin-agar was directly supplemented with colloidal chitin (5 g/l and bromocresol purple (0.15 g/l. The ability of antagonistic

Temperature Simulation of Greenhouse with CFD Methods and Optimal Sensor Placement

OpenAIRE

Yanzheng Liu; Jing Chen; Yazhou Lv; Xiaojie Li

2014-01-01

The accuracy of information monitoring is significant to increase the effect of Greenhouse Environment Control. In this paper, by taking simulation for the temperature field in the greenhouse as an example, the CFD (Computational Fluid Dynamics) simulation model for measuring the microclimate environment of greenhouse with the principle of thermal environment formation was established, and the temperature distributions under the condition of mechanical ventilation was also simulated. The resu...

Greenhouse effect: effects on refrigerating and air conditioning industries; Effet de serre: impacts sur les professions du froid et de la climatisation

Energy Technology Data Exchange (ETDEWEB)

Le Boru, B. [Association Francaise de Froid, Alliance Froid Climatisation Environnement, 75 - Paris (France)

1997-12-31

The various factors (refrigerant characteristics, design and operating performance, insulation type, etc.) involved in greenhouse gas emission from refrigerating and air conditioning equipment are listed with the potential actions that may be taken at the different stages of equipment design, engineering, installation, operation, maintenance and dismantling, in order to reduce pollutant emissions

Seedling growth in greenhouse conditions of the forest species Dialium guianense (Aubl. Sandwith

Directory of Open Access Journals (Sweden)

Georgina Vargas Simon

2018-01-01

Full Text Available Dialium guianense is used for its wood and fruit production, and is a tropical tree species native to evergreen forests. Given the threat these forests face, the purpose of this work was to evaluate the initial growth of the plant under greenhouse conditions, for aiming in the development of propagation programs. Seedlings of the species were transplanted to nursery bags under a completely randomized design and grown for 10 months with an initial population of 200 plants. At the end of the experiment, the shoot and root reached lengths of 32.8 and 28.9 cm, respectively. The average number of composite leaves was 12.3 each with seven leaflets. The average biomass was 2.5 g for the shoot, 1.6 g for roots, and 3.7 g for leaves, with a shoot/root around four. The average relative growth rate (RGR was 15 mg g-1 day-. These characteristics indicate that D. guianense is a late successional species.

Optimal space utilization of a greenhouse using multi-rack tray system: Thermal modeling and experimental validation

International Nuclear Information System (INIS)

Sethi, V.P.; Dubey, R.K.

2008-01-01

In this study, upper space inside an east-west oriented greenhouse (where the micro-climate is also under control) is optimised for producing maximum number of nursery plants by developing a multi-rack tray system (MRTS). The MRTS is designed in such a way that the vertical distance between the two consecutive trays (H) and width of the tray (W) is optimised for different months of the year at different latitudes so that the shadow of the upper tray does not fall on the lower one. The number of stacks in a greenhouse of fixed height (say 4 m) is a direct function of the maximum altitude angle of the sun at noon (α s ) at particular latitude. It is observed that at 10 deg. N and 20 deg. N latitudes α s remains greater than 45 deg. (H/W > 1) even during the winter months. It means not more than two stacks are possible inside a 4 m high greenhouse during December and January. The computations show that at 30 deg. N, 40 deg. N and 50 deg. N latitude, the number of stacks inside a greenhouse can be five, seven and twelve, respectively during the winter months of December and January. A transient thermal model coupled with MRTS is also developed to predict the soil, plant and air temperature inside the greenhouse. It is observed that the predicted and measured values are in close agreement. It is also observed that due to the increased mass of soil (in the trays) inside the greenhouse and due to reduced conduction losses to the ground beneath, MRTS also acted as a soil heat storage system before germination of the plants which stored heat during the sun-shine hours and released the same during the off-shine hours and resulted in 5-2deg. C higher inside air temperature till the early night hours as compared to ambient air temperature. Nursery of marigold (ornamental plant) is successfully raised using the MRTS inside a 3 m high greenhouse having three stacks at 30 deg. N latitude. Experiments showed that there was almost uniform growth of plants in all the three trays

Modeling and Experimental Studies for the Thermal Performance of a Ground Heat Storage System Integrated with a Greenhouse

International Nuclear Information System (INIS)

Kooli, Sami; Lazaar, Mariem; Hazami, Majdi; Farhat, Abdelhamid; Belghith, Ali

2009-01-01

A thermal model has been developed to investigate the potential of using the stored thermal energy of the ground for greenhouse heating and cooling with the help of a ground heat storage system (GHSS) integrated with the greenhouse located in the premises of CRTEn, Tunis, Tunisia. Experiments were conducted extensively throughout the years 2006-2007, and the developed model was validated against several consecutive arbitrary days experiments. The predicted and measured values of the greenhouse air temperatures and humidities that were verified, in terms of root mean square deviation and correlation coefficient, exhibited fair agreement. The results of this study showed that the GHS system kept the inside air temperature 1-3 degree higher than that of outside air at nighttime. The main reason for this low efficiency is due to the weak heat transfer area of the water-air heat exchanger. The simulation results indicate that the GHSS does not yield any significant effect for cooling greenhouses during sunny daytime. The GHSS fulfils its full potential for a heat transfer area of 150 m 2 . With this area, there occurs 4-6 degree rise of temperature in greenhouse as compared to the temperatures without GHSS and respectively 5-7.5 degree rise in greenhouse as compared to outside air

Factors Affecting Pathogen Survival in Finished Dairy Compost with Different Particle Sizes Under Greenhouse Conditions.

Science.gov (United States)

Diao, Junshu; Chen, Zhao; Gong, Chao; Jiang, Xiuping

2015-09-01

This study investigated the survival of Escherichia coli O157:H7 and Salmonella Typhimurium in finished dairy compost with different particle sizes during storage as affected by moisture content and temperature under greenhouse conditions. The mixture of E. coli O157:H7 and S. Typhimurium strains was inoculated into the finished composts with moisture contents of 20, 30, and 40%, separately. The finished compost samples were then sieved into 3 different particle sizes (>1000, 500-1000, and 500 μm) and stored under greenhouse conditions. For compost samples with moisture contents of 20 and 30%, the average Salmonella reductions in compost samples with particle sizes of >1000, 500-1000, and 500 μm were 2.15, 2.27, and 2.47 log colony-forming units (CFU) g(-1) within 5 days of storage in summer, respectively, as compared with 1.60, 2.03, and 2.26 log CFU g(-1) in late fall, respectively, and 2.61, 3.33, and 3.67 log CFU g(-1) in winter, respectively. The average E. coli O157:H7 reductions in compost samples with particle sizes of >1000, 500-1000, and 500 μm were 1.98, 2.30, and 2.54 log CFU g(-1) within 5 days of storage in summer, respectively, as compared with 1.70, 2.56, and 2.90 log CFU g(-1) in winter, respectively. Our results revealed that both Salmonella and E. coli O157:H7 in compost samples with larger particle size survived better than those with smaller particle sizes, and the initial rapid moisture loss in compost may contribute to the fast inactivation of pathogens in the finished compost. For the same season, the pathogens in the compost samples with the same particle size survived much better at the initial moisture content of 20% compared to 40%.

The greenhouse effect, v. 15(59)

International Nuclear Information System (INIS)

Tsitsonkov, Risto

2007-01-01

An explanation for the greenhouse effect, i.e. global warning and reasons which contribute to this effect. Greenhouse gases (GHG) and GWP (Global Warning Potential) as a factor for estimating their contributing on the greenhouse effect. Indicators of the climate change in the previous period and projecting of likely scenarios for the future. Consequences on the environment and human activities: industry, energy, agriculture, water resource. The main lines of the Kyoto Protocols and problems in its realization. Suggestions to the country strategy concerning to the acts of the Kyoto Protocol. A special attention is pointed out on the energy, its recourse, the structure of energy consumption and energy efficiency. Main sectors of the energy efficiency: buildings, industry and transport. Buildings: importance of heat insulation. District heating, suggestions for space heating. Heat pumps and CHP. Air conditioning and refrigeration. Industry: process heating, and integrated energy system, heat recovery, refrigeration, compressed air. Need of quality maintenance and servicing. Monitoring and automatic control. Education for energy and its saving. (Author)

The greenhouse effect, v. 15(58)

International Nuclear Information System (INIS)

Tsitsonkov, Risto

2007-01-01

An explanation for the greenhouse effect, i.e. global warning and reasons which contribute to this effect. Greenhouse gases (GHG) and GWP (Global Warning Potential) as a factor for estimating their contributing on the greenhouse effect. Indicators of the climate change in the previous period and projecting of likely scenarios for the future. Consequences on the environment and human activities: industry, energy, agriculture, water resource. The main lines of the Kyoto Protocols and problems in its realization. Suggestions to the country strategy concerning to the acts of the Kyoto Protocol. A special attention is pointed out on the energy, its recourse, the structure of energy consumption and energy efficiency. Main sectors of the energy efficiency: buildings, industry and transport. Buildings: importance of heat insulation. District heating, suggestions for space heating. Heat pumps and CHP. Air conditioning and refrigeration. Industry: process heating, and integrated energy system, heat recovery, refrigeration, compressed air. Need of quality maintenance and servicing. Monitoring and automatic control. Education for energy and its saving. (Author)

Global warming: Experimental study about the effect of accumulation of greenhouse gases in the atmosphere

Science.gov (United States)

Molto, Carlos; Mas, Miquel

2010-05-01

The project presented here was developed by fifteen year old students of the Institut Sabadell (Sabadell Secondary School. Spain). The objective of this project was to raise the students awareness' about the problem of climate change, mainly caused by the accumulation of greenhouse gases in the atmosphere. It is also intended that students use the scientific method as an effective system of troubleshooting and that they use the ICTs (Information and Communication Technologies) to elicit data and process information. To develop this project, four lessons of sixty minutes each were needed. The first lesson sets out the role of the atmosphere as an Earth's temperature regulator, highlighting the importance of keeping the levels of carbon dioxide, methane and water steam in balance. The second lesson is focused on the experimental activity that students will develop in the following lesson. In lesson two, students will present and justify their hypothesis about the experiment. Some theoretical concepts, necessary to carry out the experiment, will also be explained. The third lesson involves the core of the project, that is the experiment in the laboratory. The experiment consists on performing the atmosphere heating on a little scale. Four different atmospheres are created inside four plastic boxes heated by an infrared lamp. Students work in groups (one group for each atmosphere) and have to monitor the evolution of temperature by means of a temperature sensor (Multilog software). The first group has to observe the relationship between temperature and carbon dioxide levels increase, mainly caused by the widespread practice of burning fossil fuels by growing human populations. The task of this group is to measure simultaneously the temperature of an empty box (without CO2) and the temperature of a box with high carbon dioxide concentration. The carbon dioxide concentration is the result of the chemical reaction when sodium carbonate mixes with hydrochloric acid. The

The overall heat transfer of greenhouses covered with PE [polyethylene film] and PVC [polyvinyl chloride film] single layer: The heat insulation efficiency of greenhouses and their covering materials (1)

International Nuclear Information System (INIS)

Minagawa, H.; Tachibana, K.

1982-01-01

Overall heat transfer of polyethylene film (PE) and polyvinyl chloride film (PVC) were measured in the experimental greenhouses with hot-air heaters on the clear and on the cloudy nights during the period Nov. 1979 to Jan. 1980. Both films are 0.1 mm thick and have different physical properties for long-wave radiation. The heat insulation efficiency of the greenhouses covered with PE and PVC single layer was investigated, and the ratio of floor area to covering area for the experimental greenhouses, which is one of the indices for the heat insulation efficiency of greenhouses, was also taken into consideration. The results are as follows: 1. Using the ratio of the overall heat transfer and the overall heat transfer coefficients for the heat insulation efficiency, the PE-house revealed to be less efficient than the PVC-house. This can be due to PE being more transparent to long-wave radiation than PVC. The advantage in the PVC-house, however, decreased with the increasing of the inside-outside air temperature difference (Figs. 3 and 5). 2. The overall heat transfer coefficients of both greenhouses depended on the inside-outside temperature difference. As the temperature difference increased, the overall heat transfer coefficients decreased (Fig. 5). 3. The overall heat transfer coefficients of both greenhouses were smaller on the cloudy nights than that on the clear nights. When the condensation occurred at the interior film surface, the heat insulation efficiency of both greenhouses was increased, resulting in the decrease of the coefficient. The efficiency of the PE-house was more affected than the PVC-house when the condensation occurred (Figs. 6 and 7). 4. When the inside-outside air temperature difference was small, convective heat transferred from the outside air to the outside cover surface. With an increase in the inside-outside air temperature difference, convective heat flow occurred from the outside cover surface to the outside air. This phenomenon was

(ajst) effects of ground insulation and greenhouse

African Journals Online (AJOL)

NORBERT OPIYO AKECH

and quality of biogas generation from dairy cattle dung. The effects ... Therefore ground insulation of plastic biogas digester under greenhouse conditions significantly enhances ..... The low values obtained did not suggest failure of the system ...

Greenhouse and Energy

International Nuclear Information System (INIS)

Swaine, D.J.

1990-01-01

The book is based on papers at the conference held at Macquarie University, Australia, in December 1989. The topics include energy aspects of the greenhouse effect, effects of reduction of carbon dioxide, methane emissions, sources of energy production, various aspects of electricity, liquid building, new technology, energy management and environmental and sociological aspects. Whilist the emphasis is on Australian conditions, the approaches are of relevance to other countries. Contains lists of referees and participants. Twenty-three papers have been separately indexed

Research on Intelligent Agriculture Greenhouses Based on Internet of Things Technology

OpenAIRE

Shang Ying; Fu An-Ying

2017-01-01

Internet of things is a hot topic in the field of research, get a lot of attention, On behalf of the future development trend of the network, Internet of Things has a wide range of applications, because of the efficient and reliable information transmission in modern agriculture. In the greenhouse, the conditions of the Greenhouse determine the quality of crops, high yield and many other aspects. Research on Intelligent Agriculture Greenhouses based on Internet of Things, mainly Research on h...

Grappling with greenhouse

International Nuclear Information System (INIS)

Mitchell, C.D.

1992-01-01

A natural greenhouse effect keeps the Earth at a temperature suitable for life. Some of the gases responsible for the greenhouse effect are increasing at an unprecedented rate because of human activity. These increased levels of greenhouse gases in the atmosphere will strengthen the natural greenhouse effect, leading to an overall warming of the Earth's surface. Global warming resulting from the enhanced greenhouse effect is likely to be obscured by normal climatic fluctuations for another ten years or more. The extent of human-caused climate change will depend largely on future concentrations of greenhouse gases in the atmosphere. In turn, the composition of the atmosphere depends on the release of greenhouse gases. Releases are hard to predict, because they require an understanding of future human activity. The composition of the atmosphere also depends on the processes which remove greenhouse gases from it. This booklet is summarizing the latest research results in the form of climate change scenarios. The present scenarios of change are based on climate models, together with an understanding of how present-day climate, with its inherent natural variability, affects human activities. These scenarios present a coherent range of future possibilities for climate; they are not predictions but they serve as a useful starting point. It is estimated that human-caused climate change will affect all aspects of life in Australia, including our cities, agriculture, pests and diseases, fisheries and natural ecosystems. 15 figs., ills

Application of dynamic model to predict some inside environment variables in a semi-solar greenhouse

Directory of Open Access Journals (Sweden)

Behzad Mohammadi

2018-06-01

Full Text Available Greenhouses are one of the most effective cultivation methods with a yield per cultivated area up to 10 times more than free land cultivation but the use of fossil fuels in this production field is very high. The greenhouse environment is an uncertain nonlinear system which classical modeling methods have some problems to solve it. There are many control methods, such as adaptive, feedback and intelligent control and they require a precise model. Therefore, many modeling methods have been proposed for this purpose; including physical, transfer function and black-box modeling. The objective of this paper is to modeling and experimental validation of some inside environment variables in an innovative greenhouse structure (semi-solar greenhouse. For this propose, a semi-solar greenhouse was designed and constructed at the North-West of Iran in Azerbaijan Province (38°10′N and 46°18′E with elevation of 1364 m above the sea level. The main inside environment factors include inside air temperature (Ta and inside soil temperature (Ts were collected as the experimental data samples. The dynamic heat transfer model used to estimate the temperature in two different points of semi-solar greenhouse with initial values. The results showed that dynamic model can predict the inside temperatures in two different points (Ta and Ts with RMSE, MAPE and EF about 5.3 °C, 10.2% and 0.78% and 3.45 °C, 7.7% and 0.86%, respectively. Keywords: Semi-solar greenhouse, Dynamic model, Commercial greenhouse

Counterbalancing for serial order carryover effects in experimental condition orders

OpenAIRE

Brooks, Joseph L

2012-01-01

Reactions of neural, psychological, and social systems are rarely, if ever, independent of previous inputs and states. The potential for serial order carryover effects from one condition to the next in a sequence of experimental trials makes counterbalancing of condition order an essential part of experimental design. Here, a method is proposed for generating counterbalanced sequences for repeated-measures designs including those with multiple observations of each condition on one participant...

Plant response-based sensing for control starategies in sustainable greenhouse production

International Nuclear Information System (INIS)

Kacira, M.; Sase, S.; Okushima, L.; Ling, P.P.

2005-01-01

The effect of environmental variability is one of the major concerns in experimental design for both research in plant systems and greenhouse plant production. Microclimates surrounding plants are not usually uniform. Therefore, many samples and sensors are required to obtain a true representation of the plant population. A plant monitoring system capable of reducing the required number of samples by reducing environmental variability would be more advantageous. To better understand plant-environment interaction, it is essential to study plants, microclimate surrounding the plants and the growth media. To achieve this, the monitoring system must be equipped with proper instrumentation. To achieve proper management practices and sustainable greenhouse production, it is essential first to understand plants and their interactions with their surroundings and then establish plant response-based sensing and control strategies for greenhouse processes. Therefore, an effort was conducted to review and discuss current sensing and control strategies in greenhouse research and plant production and provide recommendations on plant response-based sensing and control strategies for sustainable greenhouse production

Honeybees as an aid in improving labour conditions in sweet bell pepper greenhouses: reduction of pollen allergy

NARCIS (Netherlands)

Steen, van der J.J.M.; Blacquière, T.; Jong, de N.W.; Groot, de H.

2004-01-01

Sweet bell pepper is the most important greenhouse vegetable crop in the Netherlands. It is grown on an area of 10,000 hectares, and about 8000 people are working in these greenhouses. One third of these workers sooner or later develop an occupational allergy to the sweet bell pepper pollen. The

Counterbalancing for Serial Order Carryover Effects in Experimental Condition Orders

Science.gov (United States)

Brooks, Joseph L.

2012-01-01

Reactions of neural, psychological, and social systems are rarely, if ever, independent of previous inputs and states. The potential for serial order carryover effects from one condition to the next in a sequence of experimental trials makes counterbalancing of condition order an essential part of experimental design. Here, a method is proposed…

Increased SBPase activity improves photosynthesis and grain yield in wheat grown in greenhouse conditions.

Science.gov (United States)

Driever, Steven M; Simkin, Andrew J; Alotaibi, Saqer; Fisk, Stuart J; Madgwick, Pippa J; Sparks, Caroline A; Jones, Huw D; Lawson, Tracy; Parry, Martin A J; Raines, Christine A

2017-09-26

To meet the growing demand for food, substantial improvements in yields are needed. This is particularly the case for wheat, where global yield has stagnated in recent years. Increasing photosynthesis has been identified as a primary target to achieve yield improvements. To increase leaf photosynthesis in wheat, the level of the Calvin-Benson cycle enzyme sedoheptulose-1,7-biphosphatase (SBPase) has been increased through transformation and expression of a Brachypodium distachyon SBPase gene construct. Transgenic lines with increased SBPase protein levels and activity were grown under greenhouse conditions and showed enhanced leaf photosynthesis and increased total biomass and dry seed yield. This showed the potential of improving yield potential by increasing leaf photosynthesis in a crop species such as wheat. The results are discussed with regard to future strategies for further improvement of photosynthesis in wheat.This article is part of the themed issue 'Enhancing photosynthesis in crop plants: targets for improvement'. © 2017 The Authors.

Pathogenicity of Two Species of Entomopathogenic Nematodes Against the Greenhouse Whitefly, Trialeurodes vaporariorum (Hemiptera: Aleyrodidae), in Laboratory and Greenhouse Experiments.

Science.gov (United States)

Rezaei, Nastaran; Karimi, Javad; Hosseini, Mojtaba; Goldani, Morteza; Campos-Herrera, Raquel

2015-03-01

The greenhouse whitefly Trialeurodes vaporariorum (Hemiptera: Aleyrodidae) is a polyphagous pest in greenhouse crops. The efficacy of two entomopathogenic nematodes (EPN), Steinernema feltiae and Heterorhabditis bacteriophora, as biological control agents against T. vaporariorum was evaluated using two model crops typical of vegetable greenhouse productions: cucumber and pepper. Laboratory tests evaluated adults and second nymphal instars for pest susceptibility to different EPN species at different concentrations of infective juveniles (IJ; 0, 25, 50, 100, 150, 200, and 250 IJ per cm(2)); subsequent greenhouse trials against second nymphal instars on cucumber and pepper plants evaluated more natural conditions. Concentrations were applied in combination with Triton X-100 (0.1% v/v), an adjuvant for increasing nematode activity. In laboratory studies, both life stages were susceptible to infection by the two nematode species, but S. feltiae recorded a lower LC50 than H. bacteriophora for both insect stages. Similarly, in greenhouse experiments, S. feltiae required lower concentrations of IJ than H. bacteriophora to reach the same mortality in nymphs. In greenhouse trials, a significant difference was observed in the triple interaction among nematode species × concentration × plant. Furthermore, the highest mortality rate of the second nymphal instars of the T. vaporariorum was obtained from the application of S. feltiae concentrated to 250 IJ/cm(2) on cucumber (49 ± 1.23%). The general mortality caused by nematodes was significantly higher in cucumber than in pepper. These promising results support further investigation for the optimization of the best EPN species/concentration in combination with insecticides or adjuvants to reach a profitable control of this greenhouse pest.

Review. Advantages and disadvantages of control theories applied in greenhouse climate control systems

Energy Technology Data Exchange (ETDEWEB)

Duarte-Galvan, C.; Torres-Pacheco, I.; Guevara-Gonzalez, R. G.; Romero-Troncoso, R. J.; Contreras-Medina, L. M.; Rios-Alcaraz, M. A.; Millan-Almaraz, J. R.

2012-07-01

Today agriculture is changing in response to the requirements of modern society, where ensuring food supply through practices such as water conservation, reduction of agrochemicals and the required planted surface, which guarantees high quality crops are in demand. Greenhouses have proven to be a reliable solution to achieve these goals; however, a greenhouse as a means for protected agriculture has the potential to lead to serious problems. The most of these are related to the inside greenhouse climate conditions where controlling the temperature and relative humidity (RH) are the main objectives of engineering. Achieving appropriate climate conditions to ensure high yield and quality crops reducing energy consumption have been the objective of investigations for some time. Different schemes in control theories have been applied in this field to solve the aforementioned problems. Therefore, the objective of this paper is to present a review of different control techniques applied in protected agriculture to manage greenhouse climate conditions, presenting advantages and disadvantages of developed control platforms in order to suggest a design methodology according to results obtained from different investigations. (Author) 64 refs.

Chapter 14. Greenhouses

Energy Technology Data Exchange (ETDEWEB)

Rafferty, Kevin D.

1998-01-01

Greenhouse heating is one of the most common uses of geothermal resources. Because of the significant heating requirements of greenhouses and their ability to use very low- temperature fluids, they are a natural application. The evaluation of a particular greenhouse project involves consideration of the structure heating requirements, and the system to meet those requirements. This chapter is intended to provide information on each of these areas.

Iterest grows for Dutch mid-tech and low-tech greenhouse technology : A greenhouse to suit all tropical conditions (interview with Anne Elings)

NARCIS (Netherlands)

Kierkels, T.; Elings, A.

2014-01-01

The Netherlands sets the standard for high-tech greenhouses worldwide. But increasingly suppliers are looking too at possibilities within the mid-tech and even the low-tech market segments. The Dutch government is supporting demonstration projects, for example in Mexico, East Africa and Malaysia.

Greenhouse effects of aircraft emissions

International Nuclear Information System (INIS)

Fortuin, J.P.F.; Wauben, W.M.F.; Dorland, R. van; Kelder, H.

1996-01-01

Ranges for direct and indirect greenhouse effects due to present day aircraft emissions are quantified for northern midlatitudes, using the concept of fixed temperature (FT) radiative forcing as calculated with a radiative transfer model. The direct greenhouse effects considered here are from emissions of carbon dioxide, water vapor, and nitrogen dioxide. To calculate the concentration increases of carbon dioxide and stratospheric water vapor, an analytical expression is developed based on a linear approximation of global fuel burn versus time. Unlike the expressions currently used in the literature, the authors' expression does not account for emission rates only, but also for a loss term--hence making it more suitable for shorter lived emittants. For midlatitude summer conditions, a total radiative forcing ranging from 0.04 to 0.09 Wm -2 is calculated for the direct greenhouse effects, whereas for midlatitude winter the range is 0.07 to 0.26 Wm -2 . The indirect greenhouse effects considered here are sulfate aerosol formation from sulfur dioxide emissions, contrail formation from emitted water vapor and condensation nuclei, and ozone formation from NO x emissions. The total radiative forcing coming from these indirect effects range from -0.67 to 0.25 Wm -2 in summer a/nd from -0.36 to 0.21 Wm -2 in winter. Further, the global distribution of NO x and ozone increases from aircraft emissions world-wide are simulated with a three-dimensional chemistry transport model for January and July. The geographical distribution of the radiative forcing associated with the simulated ozone increases is also calculated for these months

'Home made' model to study the greenhouse effect and global warming

Science.gov (United States)

Onorato, P.; Mascheretti, P.; DeAmbrosis, A.

2011-03-01

In this paper a simplified two-parameter model of the greenhouse effect on the Earth is developed, starting from the well known two-layer model. It allows both the analysis of the temperatures of the inner planets, by focusing on the role of the greenhouse effect, and a comparison between the temperatures the planets should have in the absence of greenhouse effect and their actual ones. It may also be used to predict the average temperature of the Earth surface in the future, depending on the variations of the concentration of greenhouse gases in the atmosphere due to human activities. This model can promote an elementary understanding of global warming since it allows a simple formalization of the energy balance for the Earth in the stationary condition, in the presence of greenhouse gases. For these reasons it can be introduced in courses for undergraduate physics students and for teacher preparation.

'Home made' model to study the greenhouse effect and global warming

International Nuclear Information System (INIS)

Onorato, P; Mascheretti, P; DeAmbrosis, A

2011-01-01

In this paper a simplified two-parameter model of the greenhouse effect on the Earth is developed, starting from the well known two-layer model. It allows both the analysis of the temperatures of the inner planets, by focusing on the role of the greenhouse effect, and a comparison between the temperatures the planets should have in the absence of greenhouse effect and their actual ones. It may also be used to predict the average temperature of the Earth surface in the future, depending on the variations of the concentration of greenhouse gases in the atmosphere due to human activities. This model can promote an elementary understanding of global warming since it allows a simple formalization of the energy balance for the Earth in the stationary condition, in the presence of greenhouse gases. For these reasons it can be introduced in courses for undergraduate physics students and for teacher preparation.

Applying Time Series Analysis Model to Temperature Data in Greenhouses

Directory of Open Access Journals (Sweden)

Abdelhafid Hasni

2011-03-01

Full Text Available The objective of the research is to find an appropriate Seasonal Auto-Regressive Integrated Moving Average (SARIMA Model for fitting the inside air temperature (Tin of a naturally ventilated greenhouse under Mediterranean conditions by considering the minimum of Akaike Information Criterion (AIC. The results of fitting were as follows: the best SARIMA Model for fitting air temperature of greenhouse is SARIMA (1,0,0 (1,0,224.

Asian monsoons in a late Eocene greenhouse world.

Science.gov (United States)

Licht, A; van Cappelle, M; Abels, H A; Ladant, J-B; Trabucho-Alexandre, J; France-Lanord, C; Donnadieu, Y; Vandenberghe, J; Rigaudier, T; Lécuyer, C; Terry, D; Adriaens, R; Boura, A; Guo, Z; Soe, Aung Naing; Quade, J; Dupont-Nivet, G; Jaeger, J-J

2014-09-25

The strong present-day Asian monsoons are thought to have originated between 25 and 22 million years (Myr) ago, driven by Tibetan-Himalayan uplift. However, the existence of older Asian monsoons and their response to enhanced greenhouse conditions such as those in the Eocene period (55-34 Myr ago) are unknown because of the paucity of well-dated records. Here we show late Eocene climate records revealing marked monsoon-like patterns in rainfall and wind south and north of the Tibetan-Himalayan orogen. This is indicated by low oxygen isotope values with strong seasonality in gastropod shells and mammal teeth from Myanmar, and by aeolian dust deposition in northwest China. Our climate simulations support modern-like Eocene monsoonal rainfall and show that a reinforced hydrological cycle responding to enhanced greenhouse conditions counterbalanced the negative effect of lower Tibetan relief on precipitation. These strong monsoons later weakened with the global shift to icehouse conditions 34 Myr ago.

Machine Induced Experimental Background Conditions in the LHC

CERN Document Server

Levinsen, Yngve Inntjore; Stapnes, Steinar

2012-09-19

The Large Hadron Collider set a new energy record for particle accelerators in late 2009, breaking the previous record held by Tevatron of 2 TeV collision energy. The LHC today operates at a collision energy of 7 TeV. With higher beam energy and intensity, measures have to be taken to ensure optimal experimental conditions and safety of the machine and detectors. Machine induced experimental background can severely reduce the quality of experimental triggers and track reconstruction. In a worst case, the radiation levels can be damaging for some of the subdetectors. The LHC is a particular challenge in this regard due to the vastly different operating conditions of the different experiments. The nominal luminosity varies by four orders of magnitude. The unprecedented stored beam energy and the amount of superconducting elements can make it challenging to protect the accelerator itself as well. In this work we have simulated and measured the machine induced background originating from various sources: the beam...

Electrolyzer Performance Analysis of an Integrated Hydrogen Power System for Greenhouse Heating. A Case Study

Directory of Open Access Journals (Sweden)

Simone Pascuzzi

2016-07-01

Full Text Available A greenhouse containing an integrated system of photovoltaic panels, a water electrolyzer, fuel cells and a geothermal heat pump was set up to investigate suitable solutions for a power system based on solar energy and hydrogen, feeding a self-sufficient, geothermal-heated greenhouse. The electricity produced by the photovoltaic source supplies the electrolyzer; the manufactured hydrogen gas is held in a pressure tank. In these systems, the electrolyzer is a crucial component; the technical challenge is to make it work regularly despite the irregularity of the solar source. The focus of this paper is to study the performance and the real energy efficiency of the electrolyzer, analyzing its operational data collected under different operating conditions affected by the changeable solar radiant energy characterizing the site where the experimental plant was located. The analysis of the measured values allowed evaluation of its suitability for the agricultural requirements such as greenhouse heating. On the strength of the obtained result, a new layout of the battery bank has been designed and exemplified to improve the performance of the electrolyzer. The evaluations resulting from this case study may have a genuine value, therefore assisting in further studies to better understand these devices and their associated technologies.

Humidification - Fogging and other evaporative cooling in greenhouses

NARCIS (Netherlands)

Nederhoff, E.M.; Weel, van P.A.

2011-01-01

Fogging, misting, roof sprinklers, pad-and-fan and other techniques based on water evaporation are effective tools for improving the growing conditions in a greenhouse when humidity is low. They should be used wisely though.

Accounting for variation in designing greenhouse experiments with special reference to greenhouses containing plants on conveyor systems

Science.gov (United States)

2013-01-01

Background There are a number of unresolved issues in the design of experiments in greenhouses. They include whether statistical designs should be used and, if so, which designs should be used. Also, are there thigmomorphogenic or other effects arising from the movement of plants on conveyor belts within a greenhouse? A two-phase, single-line wheat experiment involving four tactics was conducted in a conventional greenhouse and a fully-automated phenotyping greenhouse (Smarthouse) to investigate these issues. Results and discussion Analyses of our experiment show that there was a small east–west trend in total area of the plants in the Smarthouse. Analyses of the data from three multiline experiments reveal a large north–south trend. In the single-line experiment, there was no evidence of differences between trios of lanes, nor of movement effects. Swapping plant positions during the trial was found to decrease the east–west trend, but at the cost of increased error variance. The movement of plants in a north–south direction, through a shaded area for an equal amount of time, nullified the north–south trend. An investigation of alternative experimental designs for equally-replicated experiments revealed that generally designs with smaller blocks performed best, but that (nearly) trend-free designs can be effective when blocks are larger. Conclusions To account for variation in microclimate in a greenhouse, using statistical design and analysis is better than rearranging the position of plants during the experiment. For the relocation of plants to be successful requires that plants spend an equal amount of time in each microclimate, preferably during comparable growth stages. Even then, there is no evidence that this will be any more precise than statistical design and analysis of the experiment, and the risk is that it will not be successful at all. As for statistical design and analysis, it is best to use either (i) smaller blocks, (ii) (nearly) trend

Stable pelagic vertebrate community structure through extreme Paleogene greenhouse conditions

Science.gov (United States)

Sibert, E. C.; Friedman, M.; Hull, P. M.; Hunt, G.; Norris, R. D.

2016-02-01

The species composition (structure) and energy transfer (function) of an ecosystem is reflected by the presence and type of consumers that it supports. Here we use ichthyoliths, microfossil fish teeth and shark denticles, to assess the ecological variability of the pelagic fish community structure and composition from the Late Cretaceous to the middle Eocene from a drill core in the South Pacific gyre (DSDP Site 596). We find that the overall vertebrate community structure, as measured by the relative abundance of sharks to ray-finned fishes, has a punctuated change at the Cretaceous/Paleogene mass extinction. The vertebrate community structure remained stable throughout the Paleogene despite a five-fold increase in overall abundance of ichthyoliths during the extreme greenhouse of the Early Eocene. Further, we use a novel system to quantify the morphological variation in fish teeth. We find that the morphospace occupied by the tooth assemblage is conserved throughout the interval, with a slight expansion following the Cretaceous-Paleogene mass extinction, and the evolution of a distinct morphotype-group around the Paleocene-Eocene boundary. While there are elevated rates of morphotype origination and extinction following the Cretaceous-Paleogene mass extinction, the extreme greenhouse warming of the Early Eocene and associated increase in fish production produce near-zero origination and extinction rates. The relative stability in composition of the pelagic vertebrate community during intervals of extreme climate change and across large ranges of total fish accumulation, suggests that pelagic ecosystem structure is robust to climate events, and that the overall structure of the pelagic fish community may be decoupled from both climate and ecosystem function.

Improvement in greenhouse solar drying using inclined north wall reflection

Energy Technology Data Exchange (ETDEWEB)

Sethi, V.P. [Department of Mechanical Engineering, Punjab Agricultural University, Ludhiana 141004, Punjab (India); Arora, Sadhna [Department of Processing and Food Engineering, Punjab Agricultural University, Ludhiana 141004, Punjab (India)

2009-09-15

A conventional greenhouse solar dryer of 6 m{sup 2} x 4 m{sup 2} floor area (east-west orientation) was improved for faster drying using inclined north wall reflection (INWR) under natural as well as forced convection mode. To increase the solar radiation availability onto the product (to be dried) during extreme summer months, a temporary inclined wall covered with aluminized reflector sheet (of 50 {mu}m thickness and reflectance 0.93) was raised inside the greenhouse just in front of the vertical transparent north wall. By doing so, product fully received the reflected beam radiation (which otherwise leaves through the north wall) in addition to the direct total solar radiation available on the horizontal surface during different hours of drying. The increment in total solar radiation input enhanced the drying rate of the product by increasing the inside air and crop temperature of the dryer. Inclination angle of the reflective north wall with vertical ({beta}) was optimized for various selective widths of the tray W (1.5, 2, 2.5 and 3 m) and for different realistic heights of existing vertical north wall (h) at 25 N, 30 N and 35 N latitudes (hot climatic zones). Experimental performance of the improved dryer was tested during the month of May 2008 at Ludhiana (30.56 N) climatic conditions, India by drying bitter gourd (Momordica charantia Linn) slices. Results showed that by using INWR under natural convection mode of drying, greenhouse air and crop temperature increased by 1-6.7 C and 1-4 C, respectively, during different drying hours as compared to, when INWR was not used and saved 13.13% of the total drying time. By using INWR under forced convection mode of drying, greenhouse air and crop temperature increased by 1-4.5 C and 1-3 C, respectively, during different drying hours as compared to, when INWR was not used and saved 16.67% of the total drying time. (author)

Simulation of thermal environment in a three-layer vinyl greenhouse by natural ventilation control

Science.gov (United States)

Jin, Tea-Hwan; Shin, Ki-Yeol; Yoon, Si-Won; Im, Yong-Hoon; Chang, Ki-Chang

2017-11-01

A high energy, efficient, harmonious, ecological greenhouse has been highlighted by advanced future agricultural technology recently. This greenhouse is essential for expanding the production cycle toward growth conditions through combined thermal environmental control. However, it has a negative effect on farming income via huge energy supply expenses. Because not only production income, but operating costs related to thermal load for thermal environment control is important in farming income, it needs studies such as a harmonious ecological greenhouse using natural ventilation control. This study is simulated for energy consumption and thermal environmental conditions in a three-layered greenhouse by natural ventilation using window opening. A virtual 3D model of a three-layered greenhouse was designed based on the real one in the Gangneung area. This 3D model was used to calculate a thermal environment state such as indoor temperature, relative humidity, and thermal load in the case of a window opening rate from 0 to 100%. There was also a heat exchange operated for heating or cooling controlled by various setting temperatures. The results show that the cooling load can be reduced by natural ventilation control in the summer season, and the heat exchange capacity for heating can also be simulated for growth conditions in the winter season.

Simulation of thermal environment in a three-layer vinyl greenhouse by natural ventilation control

Directory of Open Access Journals (Sweden)

Jin Tea-Hwan

2017-01-01

Full Text Available A high energy, efficient, harmonious, ecological greenhouse has been highlighted by advanced future agricultural technology recently. This greenhouse is essential for expanding the production cycle toward growth conditions through combined thermal environmental control. However, it has a negative effect on farming income via huge energy supply expenses. Because not only production income, but operating costs related to thermal load for thermal environment control is important in farming income, it needs studies such as a harmonious ecological greenhouse using natural ventilation control. This study is simulated for energy consumption and thermal environmental conditions in a three-layered greenhouse by natural ventilation using window opening. A virtual 3D model of a three-layered greenhouse was designed based on the real one in the Gangneung area. This 3D model was used to calculate a thermal environment state such as indoor temperature, relative humidity, and thermal load in the case of a window opening rate from 0 to 100%. There was also a heat exchange operated for heating or cooling controlled by various setting temperatures. The results show that the cooling load can be reduced by natural ventilation control in the summer season, and the heat exchange capacity for heating can also be simulated for growth conditions in the winter season.

Are greenhouse gas emissions from international shipping a type of marine pollution?

Science.gov (United States)

Shi, Yubing

2016-12-15

Whether greenhouse gas emissions from international shipping are a type of marine pollution is a controversial issue and is currently open to debate. This article examines the current treaty definitions of marine pollution, and applies them to greenhouse gas emissions from ships. Based on the legal analysis of treaty definitions and relevant international and national regulation on this issue, this article asserts that greenhouse gas emissions from international shipping are a type of 'conditional' marine pollution. Copyright © 2016 Elsevier Ltd. All rights reserved.

Changes on sewage sludge stability after greenhouse drying

Science.gov (United States)

Soriano-Disla, J. M.; Houot, S.; Imhoff, M.; Valentin, N.; Gómez, I.; Navarro-Pedreño, J.

2009-04-01

The progressive implementation of the Urban Waste Water Treatment Directive 91/271/EEC in all the European member states is increasing the quantities of sewage sludge requiring disposal. Sludge application onto cultivated soils as organic fertilizers allows the recycling of nutrients. The application of only dehydrated sludges has generated many problems including unpleasant odours and difficult management (regarding transport and application) related to their high water content. One way to overcome these problems, in a cheap and clean way, is the drying of sludges using the energy of the sun under greenhouse conditions. This drying may affect sludge chemical characteristics including organic matter stability and nitrogen availability, parameters which have to be controlled for the proper management of dry sludge application onto soils. For this reason, the main aim of this work was to study the impact of greenhouse drying of different sewage sludges on their organic matter stability and nitrogen availability, assessed by biochemical fractionation and mineralization assays. Three sewage sludges were sampled before (dehydrated sludges) and after greenhouse drying (dried sludges). The analyses consisted of: humidity, organic matter, mineral and organic N contents, N and C mineralization during 91-day laboratory incubations in controlled conditions, and biochemical fractionation using the Van Soest procedure. Greenhouse drying decreased the water content from 70-80% to 10% and also the odours, both of which will improve the management of the final product from the perspective of application and transport. We also found that drying reduced the organic matter content of the sludges but not the biodegradability of the remaining carbon. Organic N mineralization occurred during greenhouse drying, explaining why mineral N content tended to increase and the potential mineralization of organic nitrogen decreased after greenhouse drying. The biochemical stability did not

Performance of a day/night water heat storage system for heating and cooling of semi-closed greenhouses in mild winter climate

NARCIS (Netherlands)

Baeza, E.J.; Pérez Parra, J.J.; López, J.C.; Gázquez, J.C.; Meca, D.E.; Stanghellini, C.; Kempkes, F.L.K.; Montero, J.I.

2012-01-01

A novel system for heating/cooling greenhouses based on air/water heat exchangers connected to a thermally stratified water storage tank was tested in a small greenhouse compartment at the Experimental Station of the Cajamar Foundation in Almería, Spain. The system maintained a closed greenhouse (no

Occupational safety and health practices among flower greenhouses workers from Alto Tietê region (Brazil)

International Nuclear Information System (INIS)

Ribeiro, Marcela G.; Colasso, Camilla G.; Monteiro, Paula P.; Filho, Walter R. Pedreira; Yonamine, Maurício

2012-01-01

In this preliminary study the occupational safety and health practices among flower greenhouses workers were evaluated. The study was carried out in the alto Tietê region, located at the Sao Paulo State, Brazil. Inadequate welfare facilities; poor pesticide storage, use and disposal conditions; use of highly toxic pesticides; lack of adequate data regarding pesticide use; and incorrect use and maintenance of PPE were observed in most of the visited greenhouses. These results suggest that, in greenhouses, workers may be at higher risk of pesticide exposure, due to many factors that can intensify the exposure such as the lack of control on reentry intervals after pesticide application. Specific regulations are needed to ensure better OSH practices on pesticide use and to improve working conditions in greenhouses, in order to deal with the peculiarities of greenhouse working environment. Some of the special requirements for greenhouses workers' protection are the establishment of ventilation criteria for restricted entry interval; clear reentry restrictions; and EPI for workers other than applicators that need to enter the greenhouse before expiring REI interval. Another important way to improve OSH practices among workers includes the distribution of simple guidelines on the dos and don'ts regarding OSH practices in greenhouses and extensively training interventions to change the perception of hazards and the behavior towards risk. - Highlights: ► Occupational safety and health practices among flower greenhouses workers were evaluated. ► Lack of clear reentry restrictions can intensify the exposure in greenhouses. ► Specific regulations dealing with the peculiarities of greenhouse working environment are needed. ► Distribution of simple guidelines relying on greenhouse working can improve OSH practices. ► Training interventions are important to change the workers' perception of hazards and behavior towards risk.

Increased nutrient concentrations in Lake Erie tributaries influenced by greenhouse agriculture.

Science.gov (United States)

Maguire, Timothy J; Wellen, Christopher; Stammler, Katie L; Mundle, Scott O C

2018-08-15

Greenhouse production of vegetables is a growing global trade. While greenhouses are typically captured under regulations aimed at farmland, they may also function as a point source of effluent. In this study, the cumulative impacts greenhouse effluents have on riverine macronutrient and trace metal concentrations were examined. Water samples were collected Bi-weekly for five years from 14 rivers in agriculturally dominated watersheds in southwestern Ontario. Nine of the watersheds contained greenhouses with their boundaries. Greenhouse influenced rivers had significantly higher concentrations of macronutrients (nitrogen, phosphorus, and potassium) and trace metals (copper, molybdenum, and zinc). Concentrations within greenhouse influenced rivers appeared to decrease over the 5-year study while concentrations within non-greenhouse influenced river remained constant. The different temporal pattern between river types was attributed to increased precipitation during the study period. Increases in precipitation diluted concentrations in greenhouse influenced rivers; however, non-influenced river runoff proportionally increased nutrient mobility and flow, stabilizing the observed concentrations of non-point sources. Understanding the dynamic nature of environmental releases of point and non-point sources of nutrients and trace metals in mixed agricultural systems using riverine water chemistry is complicated by changes in climatic conditions, highlighting the need for long-term monitoring of nutrients, river flows and weather data in assessing these agricultural sectors. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Dynamic modeling and verification of an energy-efficient greenhouse with an aquaponic system using TRNSYS

Science.gov (United States)

Amin, Majdi Talal

Currently, there is no integrated dynamic simulation program for an energy efficient greenhouse coupled with an aquaponic system. This research is intended to promote the thermal management of greenhouses in order to provide sustainable food production with the lowest possible energy use and material waste. A brief introduction of greenhouses, passive houses, energy efficiency, renewable energy systems, and their applications are included for ready reference. An experimental working scaled-down energy-efficient greenhouse was built to verify and calibrate the results of a dynamic simulation model made using TRNSYS software. However, TRNSYS requires the aid of Google SketchUp to develop 3D building geometry. The simulation model was built following the passive house standard as closely as possible. The new simulation model was then utilized to design an actual greenhouse with Aquaponics. It was demonstrated that the passive house standard can be applied to improve upon conventional greenhouse performance, and that it is adaptable to different climates. The energy-efficient greenhouse provides the required thermal environment for fish and plant growth, while eliminating the need for conventional cooling and heating systems.

Effectiveness of horizontal air flow fans supporting natural ventilation in a Mediterranean multi-span greenhouse

OpenAIRE

López, Alejandro; Valera, Diego Luis; Molina-Aiz, Francisco Domingo; Peña, Araceli

2013-01-01

Natural ventilation is the most important method of climate control in Mediterranean greenhouses. In this study, the microclimate and air flow inside a Mediterranean greenhouse were evaluated by means of sonic anemometry. Experiments were carried out in conditions of moderate wind (≈ 4.0 m s-1), and at low wind speed (≈ 1.8 m s-1) the natural ventilation of the greenhouse was supplemented by two horizontal air flow fans. The greenhouse is equipped with a single roof vent opening t...

Investigating the Effect of a North Wall on Energy Consumption of an East–West Oriented Single Span Greenhouse

Directory of Open Access Journals (Sweden)

H Ghasemi Mobtaker

2017-10-01

Full Text Available Introduction Greenhouse is a structure which provides the best condition for the maximum plants growth during the cold seasons. In cold climate zones such as Tabriz province, Iran, the greenhouse heating is one of the most energy consumers. It has been estimated that the greenhouse heating cost is attributed up to 30% of the total operational costs of the greenhouses. Renewable energy resources are clean alternatives that can be used in greenhouse heating. Among the renewable energy resources, solar energy has the highest potential around the world. In this regard, application of solar energy in greenhouse heating during the cold months of a year could be considerable. The rate of thermal energy required inside the greenhouse depends on the solar radiation received inside the greenhouse. Using a north brick wall in an east-west oriented greenhouse can increase the absorption of solar radiation and consequently reduces the thermal and radiation losses. Therefore, the main objective of the present study is to investigate the effect of implementing of a north wall on the solar radiation absorption and energy consumption of an east-west oriented single span greenhouse in Tabriz. Materials and Methods This study was carried out in Tabriz and a steady state analysis was used to predict the energy consumption of a single span greenhouse. For this purpose, thermal energy balance equations for different components of the greenhouse including the soil layer, internal air and plants were presented. For investigating the effect of the north wall on the energy consumption, the Ft and Fn parameters were used to calculate the radiation loss from the walls of the greenhouses. These factors were determined using a 3D–shadow analysis by Auto–CAD software. An east-west oriented single span greenhouse which has a north brick wall and is covered with a single glass sheet with 4 mm thickness was applied to validate the developed models. The measurements were

Greening the greenhouse grower

DEFF Research Database (Denmark)

Staats, Henk; Jansen, Lilian; Thøgersen, John

2011-01-01

Growing plants and flowers in greenhouses is a commercial activity that imposes a burden on the environment. Recently a system of registration, control, and licensing has been developed by the sector of greenhouse growers in the Netherlands, acknowledged by the state. The current study was executed...... to understand the achievements of the greenhouse growers within this system. We applied a social-cognitive model to understand intentions to reduce emissions and predict actual pesticide use. The social-cognitive concepts from the model were measured in a questionnaire that was completed by 743 greenhouse...

The Dynamic Greenhouse Challenge

Science.gov (United States)

Roman, Harry T.

2010-01-01

Greenhouses are marvelous devices, allowing one to enjoy the flower spectacle of summer all year round. At night, greenhouses use supplemental heat to keep the fragile plants warm. Over the last 30 years, greenhouse technology has undergone many changes, with the structures being automated and monitored and low-cost plastic structures emerging as…

MEMS climate sensor for crops in greenhouses

DEFF Research Database (Denmark)

Birkelund, Karen; Jensen, Kim Degn; Højlund-Nielsen, Emil

2010-01-01

We have developed and fabricated a multi-sensor chip for greenhouse applications and demonstrated the functionality under controlled conditions. The sensor consists of a humidity sensor, temperature sensor and three photodiodes sensitive to blue, red and white light, respectively. The humidity...... sensor responds linearly with humidity with a full scale change of 5.6 pF. The best performing design measures a relative change of 48%. The temperature sensor responds linearly with temperature with a temperature coefficient of resistance of 3.95 x 10(-3) K-1 and a sensitivity of 26.5 Omega degrees C-1...... and humidity sensors have further been tested on plants in a greenhouse, demonstrating that individual plant behavior can be monitored....

Fluorescent and high intensity discharge lamp use in chambers and greenhouses

Energy Technology Data Exchange (ETDEWEB)

Langhans, R.W. [Cornell Univ., Ithaca, NY (United States)

1994-12-31

Fluorescent and High Intensity Discharge lamps have opened up great opportunities for researchers to study plant growth under controlled environment conditions and for commercial growers to increase plant production during low/light periods. This report describes the advantages and disadvantages of using each lamp in growth chambers, growth rooms and greenhouses. Growth Chambers are small (3m x 4/m and smaller) walk-in or reach-in enclosures with programmable, accurate temperature, relative humidity (RH) and irradiance control over wide ranges. The intent of growth chambers was to replicate sunlight conditions and transfer research results directly to the greenhouse or outside. It was realized that sunlight and outside conditions could not be mimicked. Growth chambers are also used to study irradiance and spectral fluxes. Growth Rooms are usually large rooms (larger than 3m x 4m) with only lamp irradiance, but providing relatively limited ranges of environmental control (i.e., 10 to 30 C temperature, 50 to 90% RH and ambient to 1000 ppm CO{sub 2}), and commonly independent of outside conditions. Irradiance requirements for growth rooms are similar to those of growth chambers. Growth rooms are also used for growing a large number of plants in a uniform standard environment condition and in commercial horticulture for tissue culture, seed germination (plugs) and seedling growth. Greenhouses are designed to allow maximum sunlight penetration through the structure. Initially greenhouses were used to extend the growing season. Then as heating systems, and cooling systems improved, they were used year round. Low light during the winter months reduced plant growth, but with the advent of efficient lamps (HID and fluorescent) it became possible to increase growth to rates close to that in summer months. Supplementary lighting is used during low light periods of the year and anytime to ensure consistent total daily irradiance for research plants.

Disinfecting greenhouse drainage with solar energy; Desinfeccion de drenaje de invernaderos con energia solar

Energy Technology Data Exchange (ETDEWEB)

Camara Zapata, J. M.; Puerto Molina, H. M.

2004-07-01

This work shows the results of three experiments made with a thermal solar collector for disinfecting greenhouse drainage water in Orihuela (SE of Spain). The aim was to evaluate the influence of water volume to be treated on the thermal efficiency of the collector. The results show a reduction of both, the collector's optic efficiency and the losses coefficient, with increasing volumes of the treated water. Both parameters have opposite effects on the thermal efficiency of the collector. In our experimental conditions, the optimum thermal efficiency was obtained for a water-to-air temperature difference of 16 degree Centigree independently of the treated water volume. (Author)

Regional greenhouse climate effects

International Nuclear Information System (INIS)

Hansen, J.; Rind, D.; Delgenio, A.; Lacis, A.; Lebedeff, S.; Prather, M.; Ruedy, R.; Karl, T.

1990-01-01

The authors discuss the impact of an increasing greenhouse effect on three aspects of regional climate: droughts, storms and temperature. A continuous of current growth rates of greenhouse gases causes an increase in the frequency and severity of droughts in their climate model simulations, with the greatest impacts in broad regions of the subtropics and middle latitudes. But the greenhouse effect enhances both ends of the hydrologic cycle in the model, that is, there is an increased frequency of extreme wet situations, as well as increased drought. Model results are shown to imply that increased greenhouse warming will lead to more intense thunderstorms, that is, deeper thunderstorms with greater rainfall. Emanual has shown that the model results also imply that the greenhouse warming leads to more destructive tropical cyclones. The authors present updated records of observed temperatures and show that the observations and model results, averaged over the globe and over the US, are generally consistent. The impacts of simulated climate changes on droughts, storms and temperature provide no evidence that there will be regional winners if greenhouse gases continue to increase rapidly

Effects of Different Ectomycorrhizal Fungal Inoculates on the Growth of Pinus tabulaeformis Seedlings under Greenhouse Conditions

Directory of Open Access Journals (Sweden)

Nan Lu

2016-12-01

Full Text Available The tree species Pinus tabulaeformis Carr. (P. tabulaeformis is commonly planted in China due to its economic and ecological value. In order to identify one or more ectomycorrhizal (ECM fungal species for future P. tabulaeformis afforestation, we investigated the effects of five ECM fungal species: Laccaria laccata, Boletus edulis, Gomphidius viscidus, Suillus grevillei, and Suillus luteus on the growth of P. tabulaeformis seedlings under greenhouse conditions. The growth parameters of P. tabulaeformis seedlings were evaluated 90 days following fungal colonisation. The majority of seedlings were significantly affected by ECM inoculation. Mycorrhizal inoculated seedlings were taller, had more lateral roots, and a greater biomass compared with the non-mycorrhizal (CK seedlings. With the exception of G. viscidus, inoculated seedlings exhibited higher phosphorus, potassium, and nitrogen content compared with the CK seedlings. In addition, ECM colonisation increased the enzymatic activity of catalase, acidic phosphatase, protease, and the urease content in the rhizosphere soil. Our study showed that Laccaria laccata, Suillus grevillei, and Suillus luteus may be useful for improving the growth and cultivation of P. tabulaeformis seedlings. Furthermore, we observed that S. luteus inoculation increased the gas exchange parameters of P. tabulaeformis seedlings under field conditions.

Using a Novel Wireless-Networked Decentralized Control Scheme under Unpredictable Environmental Conditions.

Science.gov (United States)

Chang, Chung-Liang; Huang, Yi-Ming; Hong, Guo-Fong

2015-11-12

The direction of sunshine or the installation sites of environmental control facilities in the greenhouse result in different temperature and humidity levels in the various zones of the greenhouse, and thus, the production quality of crop is inconsistent. This study proposed a wireless-networked decentralized fuzzy control scheme to regulate the environmental parameters of various culture zones within a greenhouse. The proposed scheme can create different environmental conditions for cultivating different crops in various zones and achieve diversification or standardization of crop production. A star-type wireless sensor network is utilized to communicate with each sensing node, actuator node, and control node in various zones within the greenhouse. The fuzzy rule-based inference system is used to regulate the environmental parameters for temperature and humidity based on real-time data of plant growth response provided by a growth stage selector. The growth stage selector defines the control ranges of temperature and humidity of the various culture zones according to the leaf area of the plant, the number of leaves, and the cumulative amount of light. The experimental results show that the proposed scheme is stable and robust and provides basis for future greenhouse applications.

Using a Novel Wireless-Networked Decentralized Control Scheme under Unpredictable Environmental Conditions

Directory of Open Access Journals (Sweden)

Chung-Liang Chang

2015-11-01

Full Text Available The direction of sunshine or the installation sites of environmental control facilities in the greenhouse result in different temperature and humidity levels in the various zones of the greenhouse, and thus, the production quality of crop is inconsistent. This study proposed a wireless-networked decentralized fuzzy control scheme to regulate the environmental parameters of various culture zones within a greenhouse. The proposed scheme can create different environmental conditions for cultivating different crops in various zones and achieve diversification or standardization of crop production. A star-type wireless sensor network is utilized to communicate with each sensing node, actuator node, and control node in various zones within the greenhouse. The fuzzy rule-based inference system is used to regulate the environmental parameters for temperature and humidity based on real-time data of plant growth response provided by a growth stage selector. The growth stage selector defines the control ranges of temperature and humidity of the various culture zones according to the leaf area of the plant, the number of leaves, and the cumulative amount of light. The experimental results show that the proposed scheme is stable and robust and provides basis for future greenhouse applications.

National Greenhouse Gas Emission Inventory

Data.gov (United States)

U.S. Environmental Protection Agency — The National Greenhouse Gas Emission Inventory contains information on direct emissions of greenhouse gases as well as indirect or potential emissions of greenhouse...

The greenhouse effect

International Nuclear Information System (INIS)

Berger, A.

1991-01-01

The greenhouse effect on earth can be defined as the long wave energy trapped in the atmosphere. Climate forcing and climate system response within which climate feedback mechanisms are contained are determined. Quantitative examples illustrate what could happen if the greenhouse effect is perturbed by human activities, in particular if CO2 atmospheric concentration would double in the future. Recent satellite measurements of the greenhouse effect are given. The net cooling effect of clouds and whether or not there will be less cooling by clouds as the planet warms are also discussed

A Particle Swarm Optimization of Natural Ventilation Parameters in a Greenhouse with Continuous Roof Vents

Directory of Open Access Journals (Sweden)

Abdelhafid HASNI

2009-03-01

Full Text Available Although natural ventilation plays an important role in the affecting greenhouse climate, as defined by temperature, humidity and CO2 concentration, particularly in Mediterranean countries, little information and data are presently available on full-scale greenhouse ventilation mechanisms. In this paper, we present a new method for selecting the parameters based on a particle swarm optimization (PSO algorithm which optimize the choice of parameters by minimizing a cost function. The simulator was based on a published model with some minor modifications as we were interested in the parameter of ventilation. The function is defined by a reduced model that could be used to simulate and predict the greenhouse environment, as well as the tuning methods to compute their parameters. This study focuses on the dynamic behavior of the inside air temperature and humidity during ventilation. Our approach is validated by comparison with some experimental results. Various experimental techniques were used to make full-scale measurements of the air exchange rate in a 400 m2 plastic greenhouse. The model which we propose based on natural ventilation parameters optimized by a particle swarm optimization was compared with the measurements results.

Energy Efficiency of a Greenhouse for the Conservation of Forestry Biodiversity

Directory of Open Access Journals (Sweden)

Alvaro Marucci

2013-01-01

Full Text Available Forest biodiversity conservation is one of the most interesting and crucial problems in forestry world. Currently, the conservation methods are based on two phases: the conservation of seeds at low temperatures and the multiplication of vegetable material. This latter operation can be successfully developed in properly designed greenhouses. The aim of this paper is to define a type of greenhouse which is particularly suitable for plant material propagation in order to preserve forest biodiversity in the area of the Central Italy. Some general parameters were first defined for a correct planning of the structure, such as: the shape of the section, volume, cover material, systems for heating and cooling, and those for the control of the internal microclimate parameters (light, air temperature, and relative humidity. Considering the construction characteristics and the climatic conditions of the place, the internal microclimatic conditions have been later determined by the useful implementation in TRNSYS in order to analyse the energy efficiency of the greenhouse.

Emission of carbon. A most important component for greenhouse effect in the atmosphere

Energy Technology Data Exchange (ETDEWEB)

Milaev, V.B.; Kopp, I.Z.; Yasenski, A.N. [Scientific Research Inst. of Atmospheric Air Protection, St. Petersburg (Russian Federation)

1995-12-31

Greenhouse effect is most often defined as the probabilities of atmospheric air quasiequilibrium temperature increase as a result of air pollution due to emission of anthropogenic gaseous substances which are usually called `greenhouse gases`. Among greenhouse gases are primarily considered several gaseous substances which contain carbon atoms: carbon oxide, carbon dioxide and methane (CO, CO{sub 2} and CH{sub 4}), and chlorinated and fluorinated hydrocarbons (freons) spectra of which are transparent to solar radiation, but absorb and reradiate longwave radiation causing disturbance of quasistationary thermal regieme of the atmosphere. Qualitative estimates of the income and relative roles of different substances in occurrence of greenhouse effect differ considerable. At the modern state of knowledge the problem of greenhouse effect and greenhouse gases is considered in several aspects. The most widespread and investigated is climatic or meteorological aspect, it is discussed in a number of international works. Rather pressing is thermal physics aspect of the problem of estimating greenhouse effect, which consists in correct construction of a calculation model and usage of the most representative experimental data, since analytical methods require many assumptions, introduction of which may lead to results which differ very much. Bearing these uncertainties in mind the UNEP/WMO/ICSU conference has included into the number of the most urgent tasks in the study of greenhouse effect, the problem of determining the priority of factors which cause greenhouse effect, which in its turn predetermines the necessity to substantiate the methods of selection and criterion of comparative evaluation of such factors. (author)

Emission of carbon. A most important component for greenhouse effect in the atmosphere

Energy Technology Data Exchange (ETDEWEB)

Milaev, V B; Kopp, I Z; Yasenski, A N [Scientific Research Inst. of Atmospheric Air Protection, St. Petersburg (Russian Federation)

1996-12-31

Greenhouse effect is most often defined as the probabilities of atmospheric air quasiequilibrium temperature increase as a result of air pollution due to emission of anthropogenic gaseous substances which are usually called `greenhouse gases`. Among greenhouse gases are primarily considered several gaseous substances which contain carbon atoms: carbon oxide, carbon dioxide and methane (CO, CO{sub 2} and CH{sub 4}), and chlorinated and fluorinated hydrocarbons (freons) spectra of which are transparent to solar radiation, but absorb and reradiate longwave radiation causing disturbance of quasistationary thermal regieme of the atmosphere. Qualitative estimates of the income and relative roles of different substances in occurrence of greenhouse effect differ considerable. At the modern state of knowledge the problem of greenhouse effect and greenhouse gases is considered in several aspects. The most widespread and investigated is climatic or meteorological aspect, it is discussed in a number of international works. Rather pressing is thermal physics aspect of the problem of estimating greenhouse effect, which consists in correct construction of a calculation model and usage of the most representative experimental data, since analytical methods require many assumptions, introduction of which may lead to results which differ very much. Bearing these uncertainties in mind the UNEP/WMO/ICSU conference has included into the number of the most urgent tasks in the study of greenhouse effect, the problem of determining the priority of factors which cause greenhouse effect, which in its turn predetermines the necessity to substantiate the methods of selection and criterion of comparative evaluation of such factors. (author)

The greenhouse effect and extreme weather

International Nuclear Information System (INIS)

Groenaas, Sigbjoern; Kvamstoe, Nils Gunnar

2002-01-01

The article asserts that an anthropogenic global warming is occurring. This greenhouse effect is expected to cause more occurrences of extreme weather. It is extremely difficult, however, to relate specific weather catastrophes to global warming with certainty, since such extreme weather conditions are rare historically. The subject is controversial. The article also discusses the public debate and the risk of floods

Theory and validation of a liquid radiation filter greenhouse simulation for performance prediction

International Nuclear Information System (INIS)

Feuermann, D.; Kopel, R.; Zeroni, M.; Levi, S.; Gale, J.

1997-01-01

A greenhouse is described which has a selectively absorbing liquid radiation filter (LRF) circulating in double layered cladding. The filter removes much of the near infrared wave band of solar radiation (700 nm) while transmitting most of the photosynthetic radiation (400-700 nm). This greatly reduces the heat input to the greenhouse and, by transferring heat from day to night, facilitates better temperature control. This is particularly important for CO2 fertilization, which requires that the greenhouse should remain closed during daylight hours. A computer simulation model was developed to study the relationship between design parameters of such a LRF greenhouse and its thermal performance under different climatic conditions. The model was based on a small number of governing equations describing the major physical phenomena responsible for the greenhouse climate. Validation of the simulation was performed with data from a 330 m2 LRF greenhouse, operating in the Negev (Israel) desert highlands. The predicted greenhouse temperatures were found to agree with measured values to within one to two degrees Celsius. Performances of a LRF and a conventional greenhouse were compared using the simulation and hourly meteorological data for central Israel. For the summer season of May to October, the number of daylight hours during which the LRF greenhouse could remain closed was larger by about two-thirds than that of the conventional greenhouse

Danish greenhouse gas reduction scenarios for 2020 and 2050

Energy Technology Data Exchange (ETDEWEB)

Karlsson, K; Joergensen, Kaj [Risoe DTU, Roskilde (DK); Werling, J; OErsted Pedersen, H; Kofoed-Wiuff, A [Ea energy Analysis, Copenhagen (DK)

2008-02-15

The aim of the project presented in this report was to develop scenarios for reducing Danish greenhouse gas emissions in 2020 and 2050. The scenarius provide a basis for estimating which technologies should be combined in order to obtain future reductions in greenhouse gas emissions in a cost-effective way. The scenarios include all emissions of greenhouse gases from agriculture, industry and oil extraction activities in the North Sea as well as the transport and energy sectors. Foreign air and sea carriage is not included because emissions related to such activities are not yet subject to international climate change agreements. The scenarios focus particularly on the technological possibilities and the necessary system changes in the Danish energy system and transport sector. Parallel to this, COWI has carried out analyses for the Danish Environmental Protection Agency focussing primarily on the reduction potentials in the transport sector and other emissions. COWI's results regarding agriculture and other emissions have been included in this analysis. Two timeframes are applied in the scenarios: the medium term, 2020, and the long term, 2050. For each timeframe, we have set up indicative targets that the scenarios must reach: 1) 2020: 30 and 40 % reduction in greenhouse gas emissions compared to 1990 2) 2050: 60 and 80 % reduction in greenhouse gas emissions compared to 1990. The scenarios for 2020 focus primarily on technologies that are already commercially available, whereas the scenarios for 2050 also examine technological options at the experimental or developmental stage. This includes hydrogen technologies and fuel cells as well as CO{sub 2} capture and sequestration (CCS) technologies. The scenarios should be seen in connection with the EU objectives of a 20-30 % reduction in greenhouse gas emissions in 2020 and 60-80 % in 2050 compared to 1990. The EU's 30 % objective is contingent upon global efforts to reduce the world's greenhouse gas emissions

Combining Hector SLAM and Artificial Potential Field for Autonomous Navigation Inside a Greenhouse

Directory of Open Access Journals (Sweden)

El Houssein Chouaib Harik

2018-05-01

Full Text Available The key factor for autonomous navigation is efficient perception of the surroundings, while being able to move safely from an initial to a final point. We deal in this paper with a wheeled mobile robot working in a GPS-denied environment typical for a greenhouse. The Hector Simultaneous Localization and Mapping (SLAM approach is used in order to estimate the robots’ pose using a LIght Detection And Ranging (LIDAR sensor. Waypoint following and obstacle avoidance are ensured by means of a new artificial potential field (APF controller presented in this paper. The combination of the Hector SLAM and the APF controller allows the mobile robot to perform periodic tasks that require autonomous navigation between predefined waypoints. It also provides the mobile robot with a robustness to changing conditions that may occur inside the greenhouse, caused by the dynamic of plant development through the season. In this study, we show that the robot is safe to operate autonomously with a human presence, and that in contrast to classical odometry methods, no calibration is needed for repositioning the robot over repetitive runs. We include here both hardware and software descriptions, as well as simulation and experimental results.

Effects of Greenhouse Gas Emissions on World Agriculture, Food Consumption, and Economic Welfare

International Nuclear Information System (INIS)

Darwin, R.

2004-01-01

Because of many uncertainties, quantitative estimates of agriculturally related economic impacts of greenhouse gas emissions are often given low confidence. A major source of uncertainty is our inability to accurately project future changes in economic activity, emissions, and climate. This paper focuses on two issues. First, to what extent do variable projections of climate generate uncertainty in agriculturally related economic impacts? Second, to what extent do agriculturally related economic impacts of greenhouse gas emissions depend on economic conditions at the time of impacts? Results indicate that uncertainty due to variable projections of climate is fairly large for most of the economic effects evaluated in this analysis. Results also indicate that economic conditions at the time of impact influence the direction and size of as well as the confidence in the economic effects of identical projections of greenhouse gas impacts. The economic variable that behaves most consistently in this analysis is world crop production. Increases in mean global temperature, for example, cause world crop production to decrease on average under both 1990 and improved economic conditions and in both instances the confidence with respect to variable projections of climate is medium (e.g., 67%) or greater. In addition and as expected, CO2 fertilization causes world crop production to increase on average under 1990 and improved economic conditions. These results suggest that crop production may be a fairly robust indicator of the potential impacts of greenhouse gas emissions. A somewhat unexpected finding is that improved economic conditions are not necessarily a panacea to potential greenhouse-gas-induced damages, particularly at the region level. In fact, in some regions, impacts of climate change or CO2 fertilization that are beneficial under current economic conditions may be detrimental under improved economic conditions (relative to the new economic base). Australia plus

Measurement of radiative losses and convective transfer in a greenhouse covered with different plastics

Energy Technology Data Exchange (ETDEWEB)

Palec, G. Le [Faculte des Sciences et Techniques, Monastir (Tunisia); Champagne, J. Y.; Bernaud, P.; Bournot, P.; Muynck, B. de; Vandevelde, R.

1984-07-01

Some experimental results are presented for the determination of the convective heat transfer coefficient between the cover of the greenhouse and the ground. These results are only valid in the case of small shelters. From these experiments, we get data of radiative losses of the greenhouse and some values of the I.R. transmission factor for several plastics. These two parameters can easily be inserted in modelisation of thermal losses, as electrical analogy type. (author)

Experimental greenhouse at the Stockholm County Council school of horticulture at Saebyholm. Foersoeksvaexthuset vid Saebyholmsskolan, Bro, Stockholms laen

Energy Technology Data Exchange (ETDEWEB)

Fryxell, R

1986-07-24

The aim of the experiment was to construct a tight, highly insulated, low energy and light intensive greenhouse in which demanding cultures could be cultivated troughout the year. Furthermore the house should have an open floorspace without blocking or shading structures, and be equipped with an airflow and ventilation system which makes airing unnecessary during the cold season. A day to night energy storage system should replace conventional heating. The house is erected on a concrete strip foundation in which heating coils are located. Furthermore, on the top of the cantilever are two layers of transparent plastic foil. Between the layers, removable insulating porous polystyrene balls will be filled or removed as outdoor temperature and light vary. The climate air passes the evaporators of three heat pumps and is then blown through an air/water heat exchanger and an electric radiator. The heat exchanger is supplied with hot water from a water tank heated by the heat pumps. When needed the air will be reheated in the heat exchanger and radiator. The heat evolved when the air is in the heat pump evaporators is stored in the water tank, in a salt storage and in the concrete floor with its heating coils. At night when outdoor temperature is low heat is transferred from the heat storage to the greenhouse. When inside temperature or humidity becomes too high, outdoor air is added. From the two experimental periods 1982-1984 it is concluded that after certain modifications of the equipment it would be possible to grow Swedish garden produce all the year round without excessive heating costs.

Solar radiation transmissivity of a single-span greenhouse through measurements on scale models

International Nuclear Information System (INIS)

Papadakis, G.; Manolakos, D.; Kyritsis, S.

1998-01-01

The solar transmissivity of a single-span greenhouse has been investigated experimentally using a scale model, of dimensions 40 cm width and 80 cm length. The solar transmissivity was measured at 48 positions on the “ground” surface of the scale model using 48 small silicon solar cells. The greenhouse model was positioned horizontally on a specially made goniometric mechanism. In this way, the greenhouse azimuth could be changed so that typical days of the year could be simulated using different combinations of greenhouse azimuth and the position of the sun in the sky. The measured solar transmissivity distribution at the “ground” surface and the average greenhouse solar transmissivity are presented and analysed, for characteristic days of the year, for winter and summer for a latitude of 37°58′ (Athens, Greece). It is shown that for the latitude of 37°58′ N during winter, the E–W orientation is preferable to the N–S one. The side walls, and especially the East and West ones for the E–W orientation, reduce considerably the greenhouse transmissivity at areas close to the walls for long periods of the day when the angle of incidence of the solar rays to these walls is large. (author)

Effectiveness of horizontal air flow fans supporting natural ventilation in a Mediterranean multi-span greenhouse

Directory of Open Access Journals (Sweden)

Alejandro López

2013-08-01

Full Text Available Natural ventilation is the most important method of climate control in Mediterranean greenhouses. In this study, the microclimate and air flow inside a Mediterranean greenhouse were evaluated by means of sonic anemometry. Experiments were carried out in conditions of moderate wind (≈ 4.0 m s-1, and at low wind speed (≈ 1.8 m s-1 the natural ventilation of the greenhouse was supplemented by two horizontal air flow fans. The greenhouse is equipped with a single roof vent opening to the windward side and two side vents, the windward one being blocked by another greenhouse close to it, while the leeward one is free of obstacles. When no fans are used, air enters through the roof vent and exits through both side vents, thus flowing contrary to the thermal effect which causes hot air to rise and impairing the natural ventilation of the greenhouse. Using fans inside the greenhouse helps the air to circulate and mix, giving rise to a more homogeneous inside temperature and increasing the average value of normalized air velocity by 365 %. These fans also increase the average values of kinetic turbulence energy inside the greenhouse by 550 % compared to conditions of natural ventilation. As the fans are placed 4 m away from the side vents, their effect on the entrance of outside air is insufficient and they do not help to reduce the inside temperature on hot days with little wind. It is therefore recommended to place the fans closer to the side vents to allow an additional increase of the air exchange rate of greenhouses.

Molecular detection of Erwinia psidii in guava plants under greenhouse and field conditions

Directory of Open Access Journals (Sweden)

Claudênia Ferreira da Silva

2016-09-01

Full Text Available ABSTRACT: Erwinia psidii causes bacterial blight of guava ( Psidium guajava , an important disease of this crop in Brazil. The pathogen affects branches and twigs of guava trees, reducing yield significantly. Bacterial dissemination often occurs through contaminated but asymptomatic propagating plant material. The objectives of this research were to evaluate the use of BIO-PCR and conventional PCR to detect E. psidii in inoculated guava plants grown in a greenhouse and in symptomatic and asymptomatic trees from guava orchards. Erwinia psidii strain IBSBF 1576 was inoculated (107CFU mL-1 into young guava shoots and plant tissue was analysed at 0, 5, 10, and 15 days after inoculation. Symptoms were observed after 5 days and all inoculated shoots were PCR positive at all times, by both BIO-PCR and conventional PCR. Under natural infection conditions, 40 samples were tested by BIO-PCR from each of three guava orchards, 20 showing symptoms and 20 asymptomatic. PCR was positive for 58 out of 60 symptomatic samples (96.7% and for 6.7% of asymptomatic samples, showing that the method can be used to detect the pathogen at early stages of infection. This PCR method may be used as a diagnostic tool to assess bacterial survival, dissemination and disease outbreaks.

Ozone: The secret greenhouse gas

International Nuclear Information System (INIS)

Berntsen, Terje; Tjernshaugen, Andreas

2001-01-01

The atmospheric ozone not only protects against harmful ultraviolet radiation; it also contributes to the greenhouse effect. Ozone is one of the jokers to make it difficult to calculate the climatic effect of anthropogenic emissions. The greenhouse effect and the ozone layer should not be confused. The greenhouse effect creates problems when it becomes enhanced, so that the earth becomes warmer. The problem with the ozone layer, on the contrary, is that it becomes thinner and so more of the harmful ultraviolet radiation gets through to the earth. However, ozone is also a greenhouse gas and so the greenhouse effect and the ozone layer are connected

Effects of mode of inoculation on efficacy of wettable powder and oil dispersion formulations of Beauveria bassiana applied against Colorado potato beetle larvae under low-humidity greenhouse conditions

Science.gov (United States)

The effects of inoculation method on efficacy of two formulations of Beauveria bassiana strain GHA against Colorado potato beetle larvae were investigated. Under low-humidity greenhouse conditions, 57% mortality was observed among groups of second-instar larvae exposed directly to sprays of B. bass...

Yield, nitrogen uptake and nitrogen use efficiency by tomato, pepper, cucumber, melon and eggplant as affected by nitrogen rates applied with drip-irrigation under greenhouse conditions

International Nuclear Information System (INIS)

Halitligil, M.B.; Akin, A.I.; Kislal, H.; Ozturk, A.; Deviren, A.

2002-01-01

A number of experiments were conducted to investigate the influence of different N rates applied through drip irrigation on the growth and N uptake by tomato, pepper, cucumber, melon and eggplant under greenhouse conditions. It was found that, for tomato, the % NUE was significantly increased by applying the N fertilizer through fertigation (53.9%) as compared to the soil application (34.0%) at 100 mg N/L. In general, any further increase of N fertilizer did not have an improving effect on the tomato yield. With pepper, the % NUE was significantly increased by applying the N fertilizer in the irrigation water (49.2%) as compared to the soil application (33.9%) at the same N level (140 mg N/L), being the optimum N rate under our greenhouse conditions. At a fertilization level of 100 mg N/L with fertigation, the % NUE was significantly increased as compared to the soil application. With respectively cucumber, melon and eggplant; the % NUE with fertigation was 63.4, 21.4 and 50.8%, while with soil application it was 34,0 11.0 and 18.8%. (author)

Experimental and theoretical study on natural circulation capacity under rolling motion condition

International Nuclear Information System (INIS)

Tan Sichao; Gao Puzhen

2007-01-01

Effect of rolling motion on natural circulation capacity was studied experimentally and theoretically. Experiments were conducted under the conditions of rolling and unrolling motions. The experimental results show that natural circulation capacity decreases under rolling motion condition. A mathematic model was developed to calculate the natural circulation capacity under rolling motion condition, considering the characteristics of natural circulation, the model was modified. The calculated results agree with experimental data well. Effect of rolling motion on natural circulation was analyzed through calculation and the following conclusions were obtained: (1) The increase of flow resistance coefficient is the main reason that the natural circulation capacity decreases under rolling motion condition; (2) Non-uniform distribution of fluid mass in the pipe has also influence on natural circulation capacity. (author)

Localized climate control in greenhouses

NARCIS (Netherlands)

Booij, P.S.; Sijs, J.; Fransman, J.E.

2012-01-01

Strategies for controlling the indoor climate in greenhouses are based on a few sensors and actuators in combination with an assumption that climate variables, such as temperature, are uniform throughout the greenhouse. While this is already an improper assumption for conventional greenhouses, it

Modelling and Simulation for Energy Production Parametric Dependence in Greenhouses

Directory of Open Access Journals (Sweden)

Maurizio Carlini

2010-01-01

Full Text Available Greenhouses crops in Italy are made by using prefabricated structures, leaving out the preliminary study of optical and thermal exchanges between the external environment and the greenhouse, dealing with heating and cooling and the effects of air conditioning needed for plant growth. This involves rather significant costs that directs the interest of designers, builders, and farmers in order to seek constructive solutions to optimize the system of such emissions. This work was done by building a model of gases using TRNSYS software, and these gases then have been checked for compliance. The model was constructed considering an example of a prefabricated greenhouse, located in central of Italy. Aspects of the structural components, and thermal and optical properties are analyzed in order to achieve a representation of reality.

'Home made' model to study the greenhouse effect and global warming

Energy Technology Data Exchange (ETDEWEB)

Onorato, P; Mascheretti, P; DeAmbrosis, A, E-mail: pasquale.onorato@unipv.it, E-mail: anna.deambrosisvigna@unipv.it [Department of Physics ' A. Volta' , University of Pavia, Via Bassi 6, I-27100 Pavia (Italy)

2011-03-15

In this paper a simplified two-parameter model of the greenhouse effect on the Earth is developed, starting from the well known two-layer model. It allows both the analysis of the temperatures of the inner planets, by focusing on the role of the greenhouse effect, and a comparison between the temperatures the planets should have in the absence of greenhouse effect and their actual ones. It may also be used to predict the average temperature of the Earth surface in the future, depending on the variations of the concentration of greenhouse gases in the atmosphere due to human activities. This model can promote an elementary understanding of global warming since it allows a simple formalization of the energy balance for the Earth in the stationary condition, in the presence of greenhouse gases. For these reasons it can be introduced in courses for undergraduate physics students and for teacher preparation.

Irrigation and nitrogen level affect lettuce yield in greenhouse ...

African Journals Online (AJOL)

STORAGESEVER

2008-12-17

Dec 17, 2008 ... and it achieves very high irrigation efficiency and uses. *Corresponding ... serious harmful effect on lettuce growing (Table 1). During the ... Seeds were sown in a seed bed under greenhouse conditions on. October 20th in ...

Analysis and design of greenhouse temperature control using adaptive neuro-fuzzy inference system

Directory of Open Access Journals (Sweden)

Doaa M. Atia

2017-05-01

Full Text Available The greenhouse is a complicated nonlinear system, which provides the plants with appropriate environmental conditions for growing. This paper presents a design of a control system for a greenhouse using geothermal energy as a power source for heating system. The greenhouse climate control problem is to create a favourable environment for the crop in order to reach predetermined results for high yield, high quality and low costs. Four controller techniques; PI control, fuzzy logic control, artificial neural network control and adaptive neuro-fuzzy control are used to adjust the greenhouse indoor temperature at the required value. MATLAB/SIMULINK is used to simulate the different types of controller techniques. Finally a comparative study between different control strategies is carried out.

Assessing the greenhouse gas emissions from poultry fat biodiesel

DEFF Research Database (Denmark)

Jørgensen, Andreas; Bikker, Paul; Herrmann, Ivan Tengbjerg

2012-01-01

This article attempts to answer the question: What will most likely happen in terms of emitted greenhouse gases if the use of poultry fat for making biodiesel used in transportation is increased? Through a well-to-wheel assessment, several different possible scenarios are assessed, showing...... that under average conditions, the use of poultry fat biodiesel instead of diesel leads to a slight reduction (6%) in greenhouse gas emissions. The analysis shows that poultry fat is already used for different purposes and using poultry fat for biodiesel will therefore remove the poultry fat from its...... original use. This implies that even though the use of biodiesel is assumed to displace petrochemical diesel, the ‘original user’ of the poultry fat will have to find a substitute, whose production leads to a greenhouse gas emissions comparable to what is saved through driving on poultry fat biodiesel...

A 2nd generation static model for predicting greenhouse energy inputs, as an aid for production planning

CERN Document Server

Jolliet, O; Munday, G L

1985-01-01

A model which allows accurate prediction of energy consumption of a greenhouse is a useful tool for production planning and optimisation of greenhouse components. To date two types of model have been developed; some very simple models of low precision, others, precise dynamic models unsuitable for employment over long periods and too complex for use in practice. A theoretical study and measurements at the CERN trial greenhouse have allowed development of a new static model named "HORTICERN", easy to use and as precise as more complex dynamic models. This paper demonstrates the potential of this model for long-term production planning. The model gives precise predictions of energy consumption when given greenhouse conditions of use (inside temperatures, dehumidification by ventilation, …) and takes into account local climatic conditions (wind radiative losses to the sky and solar gains), type of greenhouse (cladding, thermal screen …). The HORTICERN method has been developed for PC use and requires less...

Life-Cycle Energy Use and Greenhouse Gas Emissions Analysis for Bio-Liquid Jet Fuel from Open Pond-Based Micro-Algae under China Conditions

OpenAIRE

Xunmin Ou; Xiaoyu Yan; Xu Zhang; Xiliang Zhang

2013-01-01

A life-cycle analysis (LCA) of greenhouse gas (GHG) emissions and energy use was performed to study bio-jet fuel (BJF) production from micro-algae grown in open ponds under Chinese conditions using the Tsinghua University LCA Model (TLCAM). Attention was paid to energy recovery through biogas production and cogeneration of heat and power (CHP) from the residual biomass after oil extraction, including fugitive methane (CH 4 ) emissions during the production of biogas and nitrous oxide (N 2 O) ...

GEOTHERMAL GREENHOUSING IN TURKEY

Directory of Open Access Journals (Sweden)

Sedat Karaman

2016-07-01

Full Text Available Use of renewable energy resources should be brought forward to reduce heating costs of greenhouses and to minimize the use of ever-depleting fossil fuels. Geothermal energy not only provides the heat required throughout plant growth, but also allow a year-long production. Geothermal resources with several other benefits therefore play significant role in agricultural activities. With regard to geothermal potential and implementation, Turkey has the 7th place in the world and the 1st place in Europe. Majority of country geothermal resources is used in greenhouse heating. The size of geothermal greenhouses increased 5 folds during the last decade and reached to 2500 decare. In this study, current status of geothermal greenhousing of Turkey was presented; problems and possible solutions were discussed.

Automated Signal Processing Applied to Volatile-Based Inspection of Greenhouse Crops

Science.gov (United States)

Jansen, Roel; Hofstee, Jan Willem; Bouwmeester, Harro; van Henten, Eldert

2010-01-01

Gas chromatograph–mass spectrometers (GC-MS) have been used and shown utility for volatile-based inspection of greenhouse crops. However, a widely recognized difficulty associated with GC-MS application is the large and complex data generated by this instrument. As a consequence, experienced analysts are often required to process this data in order to determine the concentrations of the volatile organic compounds (VOCs) of interest. Manual processing is time-consuming, labour intensive and may be subject to errors due to fatigue. The objective of this study was to assess whether or not GC-MS data can also be automatically processed in order to determine the concentrations of crop health associated VOCs in a greenhouse. An experimental dataset that consisted of twelve data files was processed both manually and automatically to address this question. Manual processing was based on simple peak integration while the automatic processing relied on the algorithms implemented in the MetAlign™ software package. The results of automatic processing of the experimental dataset resulted in concentrations similar to that after manual processing. These results demonstrate that GC-MS data can be automatically processed in order to accurately determine the concentrations of crop health associated VOCs in a greenhouse. When processing GC-MS data automatically, noise reduction, alignment, baseline correction and normalisation are required. PMID:22163594

A CO{sub 2} air conditioning system to fight against greenhouse effect; Une climatisation a CO{sub 2} pour lutter contre l'effet de serre

Energy Technology Data Exchange (ETDEWEB)

Anon.

2005-10-05

Automotive air-conditioning systems, with the induced additional fuel consumption and with the type of refrigerants used, contribute to the global warming. Several car fitters, like Delphi, have developed prototypes of CO{sub 2} air conditioners. CO{sub 2} is a greenhouse gas but is less harmful for the environment than other classical refrigerants. The use of CO{sub 2} needs a complete re-design of air-conditioning systems which have to stand pressures of 130 bars and temperatures of 165 deg. C. Short paper. (J.S.)

Solar drying of sweet pepper and garlic using the tunnel greenhouse drier

Energy Technology Data Exchange (ETDEWEB)

Condori, M.; Echazu, R.; Saravia, L. [Universidad Nacional de Salta, Inst. de Investigacion en Energia no Convencional, Salta (Argentina)

2001-04-01

A new low cost design for a forced convection greenhouse drier, the Tunnel Greenhouse Drier, has been built and tested. Its main parts are: a plastic greenhouse cover containing a drying tunnel made with transparent plastic walls; a line of carts with several stacked trays containing the product and moved manually inside the tunnel and an electrical fan that moves the hot air from the greenhouse into the tunnel. The trays receive solar radiation through the transparent walls, increasing the product temperature. Heat losses from the tunnel are low since the greenhouse temperatures are higher than ambient temperature. The main advantages of this drier are: (a) an almost continuous production since some carts with dried product come out of the tunnel every day, while the same amount of fresh product is introduced by the other tunnel extreme; (b) lower labor cost since the product handling is partly mechanized; (c) a conventional heater can be easily installed to keep a constant production rate; (d) the energy consumption is lower than in other drier types; (e) the installation can be used as a greenhouse for small production when it is not used as a drier. The prototype was built in the north of Argentina, and red sweet pepper and garlic were used as load. The drier thermal efficiency, considered as a solar collector, was calculated using the measured experimental data, and a linear relation between the drier temperature and the solar radiation was obtained. (Author)

Agriculture: Nurseries and Greenhouses

Science.gov (United States)

Nurseries and Greenhouses. Information about environmental requirements specifically relating to the production of many types of agricultural crops grown in nurseries and greenhouses, such as ornamental plants and specialty fruits and vegetables.

Técnicas experimentais para tomateiro tipo salada sob estufas plásticas Salad tomato experimental techniques in plastic greenhouse

Directory of Open Access Journals (Sweden)

Sidinei José Lopes

1998-06-01

Full Text Available Realizou-se um ensaio em branco com a cultura do tomateiro, cv. Monte Carlo, sob ambiente modificado por estufa plástica de 24 x 12m. Foram realizadas 11 colheitas dos frutos, sendo determinado o peso total. A unidade básica de colheita foi composta pelo agrupamento de três plantas na fila. O espaçamento entre as plantas na fila foi de 0,3m e 1,0m entre filas, resultando em 10 filas com 24 unidades básicas cada uma. Concluiu-se que o delineamento experimental mais adequado é o inteiramente casualizado com parcelas menores que 18 plantas na fila. Experimentos para avaliar a produtividade em função de diferentes tratamentos (adubos, biocidas, etc de uma mesma cultivar, em estufas plásticas, podem ser colhidos apenas até, aproximadamente, a terça parte inicial da produção esperada, visando economia de recursos e maior precisão. Observou-se uma estabilidade das diferenças mínimas significativas a partir de 30% do total colhido, para parcelas de três, nove e 18 plantas.An uniformity trial was carried out with tomate plants grown in a plastic greenhouse with an area of 24m x 12m. The total fruit yield of salad tomato cv. Monte Carlo was evaluated during 11 separat harvest. The basic plot was planted with three plants in the same row. The plants were grown in distances of 0.3m in the same row and by 1,0m between rows. All 24 plots were allocated in ten different rows. The results demonstrate that the completely randomized were more adequate with plots smaller than 18 plants in the same row. The yield evaluation in experiments with different traits using a same cultivar in plastic greenhouse should be conducted up to 30% of total yield. This is importam for more experimental precision and budged economy and time. Results showed that the minimal significance difference varies after 30% of the total yield, was harvested for three, nine and eighteen plants in each plot.

Greenhouse gases and global warming

International Nuclear Information System (INIS)

1995-01-01

From previous articles we have learned about the complexities of our environment, its atmosphere and its climate system. we have also learned that climate change and, therefore global warm and cool periods are naturally occurring phenomena. Moreover, all scientific evidence suggests that global warming, are likely to occur again naturally in the future. However, we have not yet considered the role of the rates of climate change in affecting the biosphere. It appears that how quickly the climate changes may be more important than the change itself. In light of this concern, let us now consider the possibility that, is due to human activity. We may over the next century experience global warming at rates and magnitudes unparalleled in recent geologic history. The following questions are answered; What can we learn from past climates? What do we know about global climates over the past 100 years? What causes temperature change? What are the greenhouse gases? How much have concentration of greenhouse gases increased in recent years? Why are increases in concentrations of greenhouse of concern? What is the e nhanced greenhouse effect ? How can human activity impact the global climate? What are some reasons for increased concentrations of greenhouse gases? What are fossil fuel and how do they transform into greenhouse gases? Who are the biggest emitters of greenhouse gases? Why are canada per capita emissions of greenhouse gases relatively high? (Author)

The Peculiar Negative Greenhouse Effect Over Antarctica

Science.gov (United States)

Sejas, S.; Taylor, P. C.; Cai, M.

2017-12-01

Greenhouse gases warm the climate system by reducing the energy loss to space through the greenhouse effect. Thus, a common way to measure the strength of the greenhouse effect is by taking the difference between the surface longwave (LW) emission and the outgoing LW radiation. Based on this definition, a paradoxical negative greenhouse effect is found over the Antarctic Plateau, which suprisingly indicates that greenhouse gases enhance energy loss to space. Using 13 years of NASA satellite observations, we verify the existence of the negative greenhouse effect and find that the magnitude and sign of the greenhouse effect varies seasonally and spectrally. A previous explanation attributes the negative greenhouse effect solely to stratospheric CO2 and warmer than surface stratospheric temperatures. However, we surprisingly find that the negative greenhouse effect is predominantly caused by tropospheric water vapor. A novel principle-based explanation provides the first complete account of the Antarctic Plateau's negative greenhouse effect indicating that it is controlled by the vertical variation of temperature and greenhouse gas absorption strength. Our findings indicate that the strong surface-based temperature inversion and scarcity of free tropospheric water vapor over the Antarctic Plateau cause the negative greenhouse effect. These are climatological features uniquely found in the Antarctic Plateau region, explaining why the greenhouse effect is positive everywhere else.

Fluorescent and high intensity discharge lamp use in chambers and greenhouses

Science.gov (United States)

Langhans, Robert W.

1994-01-01

Fluorescent and High Intensity Discharge lamps have opened up great opportunities for researchers to study plant growth under controlled environment conditions and for commercial growers to increase plant production during low/light periods. Specific technical qualities of fluorescent and HID lamps have been critically reviewed. I will direct my remarks to fluorescent and high intensity discharge (HID) lamps in growth chambers, growth rooms, and greenhouses. I will discuss the advantages and disadvantages of using each lamp in growth chambers, growth rooms and greenhouses.

Through the greenhouse window

International Nuclear Information System (INIS)

Townsley, M.

1989-01-01

Nuclear power is being promoted as the only answer to the greenhouse effect. However, power station emissions (from fossil-fuel powered stations) account for only a fraction of the total carbon dioxide emissions. And carbon dioxide accounts for only about a half of the global warming effect -the other gases which create the greenhouse effect must also be limited. Nuclear energy is neither a practical nor economic alternative. Energy efficiency and conservation is a far better answer to the greenhouse effect. (U.K.)

Greenhouse effect: Myth or reality

International Nuclear Information System (INIS)

Martin, J.L.

1992-01-01

This paper debates on greenhouse effect controversy. Natural greenhouse effect is beneficent but additional greenhouse effect, in relation with human activities, can present a major risk for humanity. However an international agreement is difficult owing to the enormous costs which could not be endured by South economies. A tax on carbon dioxide emissions would have for consequence a wave of industrial delocalizations without precedent with important unemployment in Europe and no impact on additional greenhouse effect because it is a radiative effect and it is not a classic local chemical pollution. 11 refs., 10 figs

Analysis of materials used for Greenhouse roof covering - structure using CFD

Science.gov (United States)

Subin, M. C.; Savio Lourence, Jason; Karthikeyan, Ram; Periasamy, C.

2018-04-01

Greenhouse is widely used to create a suitable environment for the growth of plant. During summer, high temperatures cause harm to the plant. This work calculates characteristics required to optimize the above-mentioned parameters using different roof structure covering materials for the greenhouse. Moreover, this work also presents a simulation of the cooling and heating system. In addition, a computer model based on Ansys Fluent has been using to predict the temperature profiles inside the greenhouse. Greenhouse roof structure shading may have a time-dependent effect the production, water and nutrient uptake in plants. An experiment was conducted in the emirate of Dubai in United Arab Emirates to discover the impact of different materials in order to have an optimal plant growth zone and yield production. These structures were poly ethylene and poly carbonate sheets of 2 different configurations. Results showed that poly carbonate sheets configuration of optimal thickness has given a high result in terms of yield production. Therefore, there is a need for appropriate material selection of greenhouse roof structure in this area of UAE. Major parameters and properties need to be considered while selecting a greenhouse roof structure are the resistance to solar radiation, weathering, thermal as well as mechanical properties and good abrasion resistance. In the present study, an experiment has been conducted to find out the material suitability of the greenhouse roof structure in terms of developing proper ambient conditions especially to minimize the energy lose by reducing the HVAC and lighting expenses. The configuration verified using the CFD, so it has been concluded that polycarbonate can be safely used in the greenhouse than other roof structure material having white or green colour.

Danish greenhouse gas reduction scenarios for 2020 and 2050

Energy Technology Data Exchange (ETDEWEB)

Karlsson, K.; Joergensen, Kaj. (Risoe DTU, Roskilde (DK)); Werling, J.; OErsted Pedersen, H.; Kofoed-Wiuff, A. (Ea energy Analysis, Copenhagen (DK))

2008-02-15

The aim of the project presented in this report was to develop scenarios for reducing Danish greenhouse gas emissions in 2020 and 2050. The scenarius provide a basis for estimating which technologies should be combined in order to obtain future reductions in greenhouse gas emissions in a cost-effective way. The scenarios include all emissions of greenhouse gases from agriculture, industry and oil extraction activities in the North Sea as well as the transport and energy sectors. Foreign air and sea carriage is not included because emissions related to such activities are not yet subject to international climate change agreements. The scenarios focus particularly on the technological possibilities and the necessary system changes in the Danish energy system and transport sector. Parallel to this, COWI has carried out analyses for the Danish Environmental Protection Agency focussing primarily on the reduction potentials in the transport sector and other emissions. COWI's results regarding agriculture and other emissions have been included in this analysis. Two timeframes are applied in the scenarios: the medium term, 2020, and the long term, 2050. For each timeframe, we have set up indicative targets that the scenarios must reach: 1) 2020: 30 and 40 % reduction in greenhouse gas emissions compared to 1990 2) 2050: 60 and 80 % reduction in greenhouse gas emissions compared to 1990. The scenarios for 2020 focus primarily on technologies that are already commercially available, whereas the scenarios for 2050 also examine technological options at the experimental or developmental stage. This includes hydrogen technologies and fuel cells as well as CO{sub 2} capture and sequestration (CCS) technologies. The scenarios should be seen in connection with the EU objectives of a 20-30 % reduction in greenhouse gas emissions in 2020 and 60-80 % in 2050 compared to 1990. The EU's 30 % objective is contingent upon global efforts to reduce the world's greenhouse gas

Greenhouse

Data.gov (United States)

Federal Laboratory Consortium — PurposeThe greenhouse at ERDC’s Cold Regions Research and Engineering Laboratory (CRREL) is used for germination and root-growth studies to support basic and field...

Examination of the conditions of a broadening of the general tax for polluting activities to the intermediate energy consumptions. Incentive mechanisms for the abatement of greenhouse gas emissions

International Nuclear Information System (INIS)

Bureau, D.

2000-05-01

Among the various existing incentive mechanisms for the abatement of greenhouse gas emissions, like the pollution regulations and the financial help for energy mastery, this document analyzes the conditions of efficiency of the negotiated voluntary agreements and of the tradable emission quotas and their articulation with the fiscality. (J.S.)

Removal of phosphate from greenhouse wastewater using hydrated lime.

Science.gov (United States)

Dunets, C Siobhan; Zheng, Youbin

2014-01-01

Phosphate (P) contamination in nutrient-laden wastewater is currently a major topic of discussion in the North American greenhouse industry. Precipitation of P as calcium phosphate minerals using hydrated lime could provide a simple, inexpensive method for retrieval. A combination of batch experiments and chemical equilibrium modelling was used to confirm the viability of this P removal method and determine lime addition rates and pH requirements for greenhouse wastewater of varying nutrient compositions. Lime: P ratio (molar ratio of CaMg(OH)₄: PO₄‒P) provided a consistent parameter for estimating lime addition requirements regardless of initial P concentration, with a ratio of 1.5 providing around 99% removal of dissolved P. Optimal P removal occurred when lime addition increased the pH from 8.6 to 9.0, suggesting that pH monitoring during the P removal process could provide a simple method for ensuring consistent adherence to P removal standards. A Visual MINTEQ model, validated using experimental data, provided a means of predicting lime addition and pH requirements as influenced by changes in other parameters of the lime-wastewater system (e.g. calcium concentration, temperature, and initial wastewater pH). Hydrated lime addition did not contribute to the removal of macronutrient elements such as nitrate and ammonium, but did decrease the concentration of some micronutrients. This study provides basic guidance for greenhouse operators to use hydrated lime for phosphate removal from greenhouse wastewater.

The greenhouse effect

International Nuclear Information System (INIS)

2004-01-01

In the framework of the sustainable development, this paper presents the greenhouse effect and its impact on the climatic change, the world interest from Rio to Buenos Aires, the human activities producing the carbon dioxide and responsible of the greenhouse effect, the carbon dioxide emission decrease possibilities and shows the necessity of the electric power producers contribution. (A.L.B.)

Greenhouse effect

International Nuclear Information System (INIS)

Lepetit, J.P.

1992-01-01

This book speaks about the growth of greenhouse gases content in the atmosphere and try to forecast the different scenarios which may happen. But, in spite of international cooperation and coordinated research programs, nobody owns the answer. So possible future climatic changes depend on the behavior of the concerned actors. A review of energy policy driven by USA, Japan, Sweden, United Kingdom and Federal Republic of Germany is given. Political management of this file and public opinion in front of greenhouse effect are also described. 7 refs., 3 figs., 6 tabs

Energy consumption estimation for greenhouse gas separation processes by clathrate hydrate formation

International Nuclear Information System (INIS)

Tajima, Hideo; Yamasaki, Akihiro; Kiyono, Fumio

2004-01-01

The process energy consumption was estimated for gas separation processes by the formation of clathrate hydrates. The separation process is based on the equilibrium partition of the components between the gaseous phase and the hydrate phase. The separation and capturing processes of greenhouse gases were examined in this study. The target components were hydrofluorocarbon (HFC-134a) from air, sulfur hexafluoride (SF 6 ) from nitrogen, and CO 2 from flue gas. Since these greenhouse gases would form hydrates under much lower pressure and higher temperature conditions than the accompanying components, the effective capturing of the greenhouse gases could be achieved by using hydrate formation. A model separation process for each gaseous mixture was designed from the basis of thermodynamics, and the process energy consumption was estimated. The obtained results were then compared with those for conventional separation processes such as liquefaction separation processes. For the recovery of SF 6 , the hydrate process is preferable to liquefaction process in terms of energy consumption. On the other hand, the liquefaction process consumes less energy than the hydrate process for the recovery of HFC-134a. The capturing of CO 2 by the hydrate process from a flue gas will consume a considerable amount of energy; mainly due to the extremely high pressure conditions required for hydrate formation. The influences of the operation conditions on the heat of hydrate formation were elucidated by sensitivity analysis. The hydrate processes for separating these greenhouse gases were evaluated in terms of reduction of global warming potential (GWP)

Greenhouse heating with a fresh water floating collector solar pond

International Nuclear Information System (INIS)

Arbel, A.; Sokolov, M.

1991-01-01

The fresh water floating collector solar pond was investigated both experimentally and theoretically in a previous work, and it is now matched, by simulation, with the heat load requirements of a greenhouse. Results of the simulation indicate that such a pond is a potential energy source for greenhouse heating. This is especially true when the material properties are such that solar absorption and storage are enhanced. This paper reports that to demonstrate this point, three sets of collectors constructed with materials of different physical (radiation) properties were tested. One set is constructed of common materials which are readily available and are normally used as covers for greenhouses. The second set made of improved materials which are also available but have a smaller long-wave transmittance. The last set made of ideal material which additionally possesses selective radiation absorption properties. Collectors made of ideal materials make a superior solar pond; thus, manufacturing films with improved properties should become a worthwhile challenge for the agricultural polyethylene-films industry. Preliminary economic studies indicate that even with the low oil (<$20/Bbl) prices which exist between 1986-1989, the fresh water floating collectors solar pond provides an economically attractive alternative to the conventional oil-burning heating system. This is especially true in mild climate areas and when the large initial investment is justified by long-term greenhouse utilization planning

Turkish tomato greenhouse gets geothermal heating

NARCIS (Netherlands)

Sikkema, A.; Maaswinkel, R.H.M.

2011-01-01

Wageningen UR Greenhouse Horticulture will set up an ultramodern greenhouse in Turkey, together with Dutch greenhouse builders and contractors. Geothermal energy will be used there to provide heat and carbon dioxide for tomato cultivation.

Exergy outcomes associated with the greenhouse effects

International Nuclear Information System (INIS)

Valero, A.; Arauzo, I.

1991-01-01

In this paper the effect on the exergy of the Earth's fossil fuels if natural environmental conditions are changed due to the greenhouse effect is studied. The change considered here is a temperature rise produced as a result of increased CO 2 concentration. The temperature change due to the increase in CO 2 concentration is modeled in accordance with the most recent studies on the greenhouse effect. The result is that the ''average fossil fuel'', based on estimates of proven reserves, will lose 0.3% of its exergy if the atmospheric concentration of CO 2 doubles. Assuming that CO 2 concentration will double over the next hundred years, this 0.3% exergy loss of proven reserves means that we will lose as much capacity to produce work as primary energy was consumed in USA and Canada during 1988

Greenhouse gas measurements from aircraft during CARVE

Science.gov (United States)

Chang, R. Y.; Miller, C. E.; Dinardo, S. J.; Karion, A.; Sweeney, C.; Daube, B.; Pittman, J. V.; Miller, J. B.; Budney, J. W.; Gottlieb, E. W.; Santoni, G. W.; Kort, E. A.; Wofsy, S. C.

2012-12-01

Permafrost in the Arctic contain large carbon pools that are currently non-labile. As the polar regions warm, these carbon reserves can be released into the atmosphere and impact the greenhouse gas budget. In order to predict future climate scenarios, we need to understand the emissions of these greenhouse gases under varying environmental conditions. This study presents aircraft measurements made as a part of the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) which flew over Alaska from May to September 2012 and captured seasonal and spatial variations. Results from in situ cavity ring down spectroscopy measurements of CO2, CH4 and CO will be discussed and compared with aircraft measurements made during the summer of 1988 as a part of the Arctic Boundary Layer Expedition as well as relevant measurements from the HIAPER Pole-to-Pole Observations experiments (2009-2011).

Greenhouse Gas Emissions from Hydroelectric Reservoirs in Tropical Regions

International Nuclear Information System (INIS)

Pinguelli Rosa, L.; Aurelio dos Santos, M.; Oliveira dos Santos, E.; Matvienko, B.; Sikar, E.

2004-01-01

This paper discusses emissions by power-dams in the tropics. Greenhouse gas emissions from tropical power-dams are produced underwater through biomass decomposition by bacteria. The gases produced in these dams are mainly nitrogen, carbon dioxide and methane. A methodology was established for measuring greenhouse gases emitted by various power-dams in Brazil. Experimental measurements of gas emissions by dams were made to determine accurately their emissions of methane (CH4) and carbon dioxide (CO2) gases through bubbles formed on the lake bottom by decomposing organic matter, as well as rising up the lake gradient by molecular diffusion. The main source of gas in power-dams reservoirs is the bacterial decomposition (aerobic and anaerobic) of autochthonous and allochthonous organic matter that basically produces CO2 and CH4. The types and modes of gas production and release in the tropics are reviewed

Heating systems of special solar-greenhouses; Calefaccion solar de invernaderos especiales

Energy Technology Data Exchange (ETDEWEB)

Iriarte, Adolfo; Bistoni, Silvia [Universidad Nacional de Catamarca, Catamarca (Argentina); Saravia, Luis [INENCO, Universidad Nacional de Salta, Salta (Argentina)

2000-07-01

A research project for producing plants by cuttings propagation is being carried out by the National Institute of Agrarian Technology (Instituto Nacional de Tecnologia Agropecuaria (INTA)). The cuttings propagation technique consists of taking a part of a mother plant (cutting) and putting it in adequate conditions to induce the formation of roots. It is composed of two main stages: the first is conducted under controlled conditions and the second one is to rusticate and acclimatize rootstocks in a half-shadowed protected area. Because of the change of environment for the rootstocks, this technique has a problem of a low percentage of survival. In this paper the facilities and the working of a special greenhouse to rusticate is described in order to allow an appropriate acclimatization before the rootstocks be transferred to the second stage and to secure higher levels of survival. This greenhouse has a double plastic cover and below the second roof it has a aluminum half-shadowed folding curtain. The heating systems for both the greenhouse and hotbed is completed with plastic exchanger-collectors placed on northern and southern sides and an outdoor packed bed. The thermal behavior of the greenhouse, the different elements used and the routine of working are analyzed. The behaviour of the special greenhouse was between the foreseen levels, showing an important decrease of convective and radiative losses and the packed bed an exchangers - collectors gave an adequate amount of energy to the system. [Spanish] La Estacion Experimental Agropecuaria del Instituto Nacional de Tecnologia Agropecuaria (INTA) en la Provincia de Catamarca en Argentina, esta llevando a cabo un proyecto para la produccion de plantas por la tecnica de propagacion agamica o asexual. La misma consiste en separar una parte de la planta (estaca o esqueje) y colocarla en condiciones favorables para que se induzca la formacion de raices. Consta de dos etapas fundamentales: la primera se realiza en un

Greenhouse Earth: A Traveling Exhibition

International Nuclear Information System (INIS)

Booth, W.H.; Caesar, S.

1992-09-01

The Franklin Institute Science Museum provided an exhibit entitled the Greenhouse Earth: A Traveling Exhibition. This 3500 square-foot exhibit on global climate change was developed in collaboration with the Association of Science-Technology Centers. The exhibit opened at The Franklin Institute on February 14, 1992, welcoming 291,000 visitors over its three-month stay. During its three-year tour, Greenhouse Earth will travel to ten US cities, reaching two million visitors. Greenhouse Earth aims to deepen public understanding of the scientific issues of global warming and the conservation measures that can be taken to slow its effects. The exhibit features hands-on exhibitry, interactive computer programs and videos, a theater production, a ''demonstration cart,'' guided tours, and lectures. supplemental educational programs at the Institute included a teachers preview, a symposium on climate change, and a ''satellite field trip.'' The development of Greenhouse Earth included front-end and formative evaluation procedures. Evaluation includes interviews with visitors, prototypes, and summative surveys for participating museums. During its stay in Philadelphia, Greenhouse Earth was covered by the local and national press, with reviews in print and broadcast media. Greenhouse Earth is the first large-scale museum exhibit to address global climate change

Energy consumption for different greenhouse constructions

Energy Technology Data Exchange (ETDEWEB)

Djevic, M.; Dimitrijevic, A. [Department for Agricultural Engineering, University of Belgrade, Faculty of Agriculture, Nemanjina 6, 11080 Belgrade (RS)

2009-09-15

In this paper the influence of greenhouse construction on energy efficiency in winter lettuce production was estimated for four different double plastic covered greenhouses in Serbia region. Plastic coverings were introduced in this region as a mean of making the plant production more energy efficient. Additionally, as a means of lowering energy consumption, tunnel structures were proposed. In order to see whether the greenhouse structure influences energy consumption, four different double plastic covered greenhouses. Two tunnel types, 9 x 58 m and 8 x 25 m, one gutter-connected structure and multi-span plastic covered greenhouse. The gutter-connected structure was 2 x 7 m wide and 39 m long while the multi-span structure was 20 x 6.4 m wide and 42 m long. On the basis of lettuce production output and the energy input, specific energy input, energy output-input ratio and energy productivity were estimated. Results show that the lowest energy consumption was obtained for multi-span greenhouse, 9.76 MJ/m{sup 2}. The highest energy consumption was obtained in tunnel, 9 x 58 m, 13.93 MJ/m{sup 2}. The highest value for output-input ratio was calculated for multi-span greenhouse (0.29), followed by gutter-connected greenhouse (0.21), tunnel 9 x 58 m (0.17) and tunnel, 8 x 25 m (0.15). Results also show that energy productivity can be higher if multi-span greenhouse structures are used. (author)

Reproductive characteristics of citrus rootstocks grown under greenhouse and field environments

Directory of Open Access Journals (Sweden)

Divanilde Guerra

2013-01-01

Full Text Available The aim of the present study was to evaluate the possible effect of environmental factors on meiosis, meiotic index, pollenviability and in vitro germination of pollen from stock plants of the rootstocks Trifoliate, ‘Swingle’, ‘Troyer’, ‘Fepagro C13’, ‘FepagroC37’ and ‘Fepagro C41’ grown in a protected environment in comparison with stock plants grown in the field. The results showed thatvalues for the characteristics analyzed in 2008, 2009 and 2010 were always higher in the field than in the greenhouse conditions. Inthe field, the average of normal meiotic cells was 60.05%, 44.44% and 60.12%, respectively, and in the greenhouse, 52.75%, 30.95%and 52.82%, respectively. Mean pollen viability in the field was 90.28%, 56.23% and 74.74%, and, in the greenhouse, 64.25%, 41.41%and 66.71%, respectively. As temperature oscillations were higher in the greenhouse than in the field, we suggest that this negativelyaffects the reproductive characteristics analyzed.

Modeling and simulation of fuzzy logic controller for optimization of the greenhouse microclimate management

Directory of Open Access Journals (Sweden)

Didi Faouzi

2017-06-01

Full Text Available Abstract. Agricultural greenhouse is largely answered in the agricultural sphere, despite the shortcomings it has, including overheating during the day and night cooling which sometimes results in the thermal inversion mainly due to its low inertia. The glasshouse dressed chapel is relatively more efficient than the conventional tunnel greenhouse. Its proliferation on the ground is more or less timid because of its relatively high cost. Agricultural greenhouse aims to create a favorable microclimate to the requirements of growth and development of culture, from the surrounding weather conditions, produce according to the cropping calendars fruits, vegetables and flower species out of season and widely available along the year. It is defined by its structural and functional architecture, the quality thermal, mechanical and optical of its wall, with its sealing level and the technical and technological accompanying. The greenhouse is a very confined environment, where multiple components are exchanged between key stakeholders and the factors are light, temperature and relative humidity. This state of thermal evolution is the level sealing of the cover of its physical characteristics to be transparent to solar, absorbent and reflective of infrared radiation emitted by the enclosure where the solar radiation trapping effect otherwise called "greenhouse effect" and its technical and technological means of air that accompany. The socio-economic analysis of populations in the world leaves appear especially the last two decades of rapid and profound transformations These changes are accompanied by changes in eating habits, mainly characterized by rising consumption spread along the year. To effectively meet this demand, greenhousesystems have evolved, particularly towards greater control of production conditions (climate, irrigation, ventilation techniques, CO supply, etc.. Technological 2 progress has allowed the development of greenhouses so that they

Empirical links between the local runaway greenhouse, super-greenhouse, and deep convection in Earth's tropics

Science.gov (United States)

Dewey, M. C.; Goldblatt, C.

2017-12-01

Energy balance requires that energy absorbed and emitted at the top of the atmosphere equal; this is maintained via the Planck feedback whereby outgoing longwave radiation (OLR) increases as surface temperature increases. There are two cases where this breaks down: the runaway greenhouse (known from planetary sciences theory) characterized by an asymptotic limit on OLR from moist atmospheres, and the super-greenhouse (known from tropical meteorology observations) where OLR decreases with surface temperature when the atmosphere is moist aloft. Here we show that the runaway greenhouse limit can be empirically observed and constrained in Earth's tropics, that the runaway and super-greenhouse occur as part of the same physical phenomenon, and that the transition through the super-greenhouse to a local runaway greenhouse is intimately linked to the onset of deep convection. A runaway greenhouse occurs when water vapour causes the troposphere to become optically thick to thermal radiation from the surface and a limit on OLR emerges as thermal emission is from a constant temperature level aloft. This limit is modelled as 282 W/m/m [Goldblatt et al, 2013]. Using satellite data from Earth's tropics, we find an empirical value of this limit of 280 W/m/m, in excellent agreement with the model.A column transitioning to a runaway greenhouse typically overshoots the runaway limit and then OLR decreases with increasing surface temperature until the runaway limit is reached after which OLR remains constant. The term super-greenhouse effect (SGE) has been used to describe OLR decreasing with surface warming, observed in these satellite measurements. We show the SGE is one and the same as the transition to a local runaway greenhouse, and represents a fundamental shift in the radiation response of the earth system, rather than simply an extension of water vapour feedback. This transition via SGE from an optically thin to optically thick troposphere is facilitated by enhanced

Plant Physiology in Greenhouses

NARCIS (Netherlands)

Heuvelink, E.; Kierkels, T.

2015-01-01

Since 2004 Ep Heuvelink and Tijs Kierkels have been writing a continuing series of plant physiology articles for the Dutch horticultural journal Onder Glas and the international edition In Greenhouses. The book Plant Physiology in Greenhouses consists of 50 of their plant physiology articles. The

Greenhouse effect: there are solutions

International Nuclear Information System (INIS)

Anon.

1997-01-01

A review of solutions that may be undertaken in order to reduce the greenhouse effect gas emissions is presented: clean energy generation through municipal, agricultural and industrial waste processing, reducing energy consumption through public transportation promotion, clean fuel buses and vehicles, or using energy efficient boilers, reduction of carbon dioxide emission from industry through process optimization, waste recycling, energy substitution and conservation, diminution of CO 2 emissions in commercial and residential sectors through space heating and air conditioning retrofitting, lighting substitution. Pollution abatement potentials are evaluated in each case, notably in France

Solar greenhouse aquaculture

Energy Technology Data Exchange (ETDEWEB)

Toever, W V

1979-01-01

Rainbow and Speckled Trout have been successfully hatched and reared in a recirculating aquaculture system. The system is integrated into the Ark greenhouse providing thermal mass for temperature regulation and supplying nutrient-rich water for plants. The system incorporates bacterial, algal and hydroponic water filtration. Various vegetable crops have been raised in the hydroponic troughs. A scaled-down system suitable for domestic solar greenhouse application is also under development.

Climate, greenhouse effect, energy

International Nuclear Information System (INIS)

Henriksen, Thormod; Kanestroem, Ingolf

2001-01-01

The book has sections on the sun as energy source, the earth climate and it's changes and factors influencing this, the greenhouse effect on earth and other planets, greenhouse gases and aerosols and their properties and importance, historic climate and paleoclimate, climatic models and their uses and limitations, future climate, consequences of climatic changes, uncertainties regarding the climate and measures for reducing the greenhouse effect. Finally there are sections on energy and energy resources, the use, sources such as fossil fuels, nuclear power, renewable resources, heat pumps, energy storage and environmental aspects and the earth magnetic field is briefly surveyed

From producer to consumer: greenhouse tomato quality as affected by variety, maturity stage at harvest, transport conditions, and supermarket storage.

Science.gov (United States)

Verheul, Michèl J; Slimestad, Rune; Tjøstheim, Irene Holta

2015-05-27

Possible causes for differences in quality traits at the time of buying were studied in two widely different red tomato types. Three maturity stages were harvested from commercial greenhouses and transferred immediately to controlled environments simulating different storage, transport, and supermarket conditions. Results show significant differences in development of color, fruit firmness, contents of soluble solids (SSC), titratable acids (TTA), phenolics, and carotenoids from harvest to sale, as related to postharvest conditions. Fruit firmness, SSC, and TTA of vine-ripened red cherry tomatoes was 30, 55 and 11% higher than for those harvested at breakers and ripened to red. Temperature, light, UVC radiation, or ethylene during 4 days transport affected tomato quality traits, and differences persisted during 3 weeks of supermarket storage. Ethylene exposure gave a 3.7-fold increase in lycopene content in cherry tomatoes, whereas UVC hormesis revealed a 6-fold increase compared with the control. Results can be used to update recommendations concerning optimal handling.

A Note on Fourier and the Greenhouse Effect

OpenAIRE

Postma, Joseph E.

2015-01-01

Joseph Fourier's discovery of the greenhouse effect is discussed and is compared to the modern conception of the greenhouse effect. It is confirmed that what Fourier discovered is analogous to the modern concept of the greenhouse effect. However, the modern concept of the greenhouse effect is found to be based on a paradoxical analogy to Fourier's greenhouse work and so either Fourier's greenhouse work, the modern conception of the greenhouse effect, or the modern definition of heat is incorr...

Separate effects of flooding and anaerobiosis on soil greenhouse gas emissions and redox sensitive biogeochemistry

Science.gov (United States)

Gavin McNicol; Whendee L. Silver

2014-01-01

Soils are large sources of atmospheric greenhouse gases, and both the magnitude and composition of soil gas emissions are strongly controlled by redox conditions. Though the effect of redox dynamics on greenhouse gas emissions has been well studied in flooded soils, less research has focused on redox dynamics without total soil inundation. For the latter, all that is...

Environmental optimal control strategies based on plant canopy photosynthesis responses and greenhouse climate model

Science.gov (United States)

Deng, Lujuan; Xie, Songhe; Cui, Jiantao; Liu, Tao

2006-11-01

It is the essential goal of intelligent greenhouse environment optimal control to enhance income of cropper and energy save. There were some characteristics such as uncertainty, imprecision, nonlinear, strong coupling, bigger inertia and different time scale in greenhouse environment control system. So greenhouse environment optimal control was not easy and especially model-based optimal control method was more difficult. So the optimal control problem of plant environment in intelligent greenhouse was researched. Hierarchical greenhouse environment control system was constructed. In the first level data measuring was carried out and executive machine was controlled. Optimal setting points of climate controlled variable in greenhouse was calculated and chosen in the second level. Market analysis and planning were completed in third level. The problem of the optimal setting point was discussed in this paper. Firstly the model of plant canopy photosynthesis responses and the model of greenhouse climate model were constructed. Afterwards according to experience of the planting expert, in daytime the optimal goals were decided according to the most maximal photosynthesis rate principle. In nighttime on plant better growth conditions the optimal goals were decided by energy saving principle. Whereafter environment optimal control setting points were computed by GA. Compared the optimal result and recording data in real system, the method is reasonable and can achieve energy saving and the maximal photosynthesis rate in intelligent greenhouse

Greenhouse gas emissions increase global warming

OpenAIRE

Mohajan, Haradhan

2011-01-01

This paper discusses the greenhouse gas emissions which cause the global warming in the atmosphere. In the 20th century global climate change becomes more sever which is due to greenhouse gas emissions. According to International Energy Agency data, the USA and China are approximately tied and leading global emitters of greenhouse gas emissions. Together they emit approximately 40% of global CO2 emissions, and about 35% of total greenhouse gases. The developed and developing industrialized co...

Identification of Natural Ventilation Parameters in a Greenhouse with Continuous Roof Vents, Using a PSO and GAs

Directory of Open Access Journals (Sweden)

Abdelhafid HASNI

2010-08-01

Full Text Available Although natural ventilation plays an important role in the affecting greenhouse climate, as defined by temperature, humidity and CO2 concentration, particularly in Mediterranean countries, little information and data are presently available on full-scale greenhouse ventilation mechanisms. In this paper, we present a new method for selecting the parameters based on a particle swarm optimization (PSO algorithm and a genetic algorithm (GA which optimize the choice of parameters by minimizing a cost function. The simulator was based on a published model with some minor modifications as we were interested in the parameter of ventilation. The function is defined by a reduced model that could be used to simulate and predict the greenhouse environment, as well as the tuning methods to compute their parameters. This study focuses on the dynamic behavior of the inside air temperature and humidity during ventilation. Our approach is validated by comparison with some experimental results. Various experimental techniques were used to make full-scale measurements of the air exchange rate in a 400 m2 plastic greenhouse. The model which we propose based on natural ventilation parameters optimized by a particle swarm optimization was compared with the measurements results. Furthermore, the PSO and the GA are used to identify the natural ventilation parameters in a greenhouse. In all cases, identification goal is successfully achieved using the PSO and compared with that obtained using the GA. For the problem at hand, it is found that the PSO outperforms the GA.

Towards the semiclosed greenhouse

NARCIS (Netherlands)

Hemming, S.

2009-01-01

What can we do right now to reduce the consumption of fossil fuels in the greenhouse sector? What technologies should we concentrate on in the future? Researchers, consultants and technology enterprises working with the greenhouse sector have tried to answer these questions in collaboration with the

Effect of freeze-thaw cycles on greenhouse gas fluxes from peat soils

Science.gov (United States)

Oh, H. D.; Rezanezhad, F.; Markelov, I.; McCarter, C. P. R.; Van Cappellen, P.

2017-12-01

The ongoing displacement of climate zones by global warming is increasing the frequency and intensity of freeze-thaw cycles in middle and high latitude regions, many of which are dominated by organic soils such as peat. Repeated freezing and thawing of soils changes their physical properties, geochemistry, and microbial community structure, which together govern the biogeochemical cycling of carbon and nutrients. In this presentation, we focus on how freeze-thaw cycles influence greenhouse gas fluxes from peat using a newly developed experimental soil column system that simulates realistic soil temperature profiles during freeze-thaw cycles. We measured the surface and subsurface changes to gas and aqueous phase chemistry to delineate the diffusion pathways and quantify soil greenhouse gas fluxes during freeze-thaw cycles using sulfur hexafluoride (SF6) as a conservative tracer. Three peat columns were assembled inside a temperature controlled chamber with different soil structures. All three columns were packed with 40 cm of undisturbed, slightly decomposed peat, where the soil of two columns had an additional 10 cm layer on top (one with loose Sphagnum moss and one with an impermeable plug). The results indicate that the release of SF6 and CO2 gas from the soil surface was influenced by the recurrent development of a physical ice barrier, which prevented gas exchange between the soil and atmosphere during freezing conditions. With the onset of thawing a pulse of SF6 and CO2 occurred, resulting in a flux of 3.24 and 2095.52 µmol/m2h, respectively, due to the build-up of gases in the liquid-phase pore space during freezing. Additionally, we developed a model to determine the specific diffusion coefficients for each peat column. These data allow us to better predict how increased frequency and intensity of freeze-thaw cycles will affect greenhouse gas emissions in northern peat soils.

A Hiatus of the Greenhouse Effect

Science.gov (United States)

Song, Jinjie; Wang, Yuan; Tang, Jianping

2016-01-01

The rate at which the global average surface temperature is increasing has slowed down since the end of the last century. This study investigates whether this warming hiatus results from a change in the well-known greenhouse effect. Using long-term, reliable, and consistent observational data from the Earth’s surface and the top of the atmosphere (TOA), two monthly gridded atmospheric and surface greenhouse effect parameters (Ga and Gs) are estimated to represent the radiative warming effects of the atmosphere and the surface in the infrared range from 1979 to 2014. The atmospheric and surface greenhouse effect over the tropical monsoon-prone regions is found to contribute substantially to the global total. Furthermore, the downward tendency of cloud activity leads to a greenhouse effect hiatus after the early 1990 s, prior to the warming pause. Additionally, this pause in the greenhouse effect is mostly caused by the high number of La Niña events between 1991 and 2014. A strong La Niña indicates suppressed convection in the tropical central Pacific that reduces atmospheric water vapor content and cloud volume. This significantly weakened regional greenhouse effect offsets the enhanced warming influence in other places and decelerates the rising global greenhouse effect. This work suggests that the greenhouse effect hiatus can be served as an additional factor to cause the recent global warming slowdown. PMID:27616203

A Hiatus of the Greenhouse Effect.

Science.gov (United States)

Song, Jinjie; Wang, Yuan; Tang, Jianping

2016-09-12

The rate at which the global average surface temperature is increasing has slowed down since the end of the last century. This study investigates whether this warming hiatus results from a change in the well-known greenhouse effect. Using long-term, reliable, and consistent observational data from the Earth's surface and the top of the atmosphere (TOA), two monthly gridded atmospheric and surface greenhouse effect parameters (Ga and Gs) are estimated to represent the radiative warming effects of the atmosphere and the surface in the infrared range from 1979 to 2014. The atmospheric and surface greenhouse effect over the tropical monsoon-prone regions is found to contribute substantially to the global total. Furthermore, the downward tendency of cloud activity leads to a greenhouse effect hiatus after the early 1990 s, prior to the warming pause. Additionally, this pause in the greenhouse effect is mostly caused by the high number of La Niña events between 1991 and 2014. A strong La Niña indicates suppressed convection in the tropical central Pacific that reduces atmospheric water vapor content and cloud volume. This significantly weakened regional greenhouse effect offsets the enhanced warming influence in other places and decelerates the rising global greenhouse effect. This work suggests that the greenhouse effect hiatus can be served as an additional factor to cause the recent global warming slowdown.

A Hiatus of the Greenhouse Effect

Science.gov (United States)

Song, Jinjie; Wang, Yuan; Tang, Jianping

2016-09-01

The rate at which the global average surface temperature is increasing has slowed down since the end of the last century. This study investigates whether this warming hiatus results from a change in the well-known greenhouse effect. Using long-term, reliable, and consistent observational data from the Earth’s surface and the top of the atmosphere (TOA), two monthly gridded atmospheric and surface greenhouse effect parameters (Ga and Gs) are estimated to represent the radiative warming effects of the atmosphere and the surface in the infrared range from 1979 to 2014. The atmospheric and surface greenhouse effect over the tropical monsoon-prone regions is found to contribute substantially to the global total. Furthermore, the downward tendency of cloud activity leads to a greenhouse effect hiatus after the early 1990 s, prior to the warming pause. Additionally, this pause in the greenhouse effect is mostly caused by the high number of La Niña events between 1991 and 2014. A strong La Niña indicates suppressed convection in the tropical central Pacific that reduces atmospheric water vapor content and cloud volume. This significantly weakened regional greenhouse effect offsets the enhanced warming influence in other places and decelerates the rising global greenhouse effect. This work suggests that the greenhouse effect hiatus can be served as an additional factor to cause the recent global warming slowdown.

Geothermal Greenhouse Information Package

Energy Technology Data Exchange (ETDEWEB)

Rafferty, K. [P.E.; Boyd, T. [ed.

1997-01-01

This package of information is intended to provide a foundation of background information for developers of geothermal greenhouses. The material is divided into seven sections covering such issues as crop culture and prices, operating costs for greenhouses, heating system design, vendors and a list of other sources of information.

Agricultural sources of greenhouse gas emissions

International Nuclear Information System (INIS)

Rochette, P.

2003-01-01

The author described different sources of greenhouse gas emissions resulting from agricultural activities and the process by which carbon dioxide, nitrous oxide, and methane are generated on Canadian farms. The author also proposed some practices that would contribute to the reduction of greenhouse gas emissions. A brief description of the greenhouse effect was also provided with special emphasis on the agricultural sector. In 1996, the Canadian agricultural sector was responsible for approximately 10 per cent of greenhouse gas emissions in the country. Given the increase in farm animals and more intensive agricultural activities, it is estimated that greenhouse gas emissions generated by the agricultural sector will increase by 20 per cent by 2010 if current practices remain in effect. The most optimistic scenarios indicate that the agricultural sector could achieve or even exceed Canada's Kyoto Protocol commitments mainly through organic material sequestration in soils. The possibility for farmers to sell greenhouse gas credits could motivate farmers into adopting various practices that reduce emissions of greenhouse gases. However, the author indicated that the best motivation for farmers is the fact that adopting such practices would also lead to more efficient agricultural production. 5 refs., 4 figs

EFFECT OF DIFFERENT SUBSTRATES ON THE GROWTH AND YIELD OF TOMATO (Lycopersicum esculentum Mill UNDER GREENHOUSE CONDITIONS

Directory of Open Access Journals (Sweden)

Luis Daniel Ortega-Martínez

2010-09-01

Full Text Available The tomato (Lycopersicum esculentum Mill is the world's second most important vegetable. In Mexico, the crop gains economic and social relevance by the generation of foreign exchange and jobs, the production systems of this vegetable have been diversified in order to increase performance, incorporating innovative technologies such as plastic covers, drop irrigation and hydroponics. One of the main factors determining the success of the crop is the substrate, being the medium in which roots were developed which have great influence on the growth and development. In thisstudy, we evaluated during the crop season 2008-2009, the effect of substrate: pine sawdust, compost of sheep manure, agricultural land and red volcanic rock, on growth and yield of tomato. The experimental design used was randomized complete block with four repetitions and ten treatments were evaluated results from a combination of substrates in a volume of 1:1, each experimental unit consisted of four plants, the studied variables were subjected to an analysis of variance (ANOVA using the statistical package Statistical Package for the Social Sciences (SPSS. The genotype used was Sun 7705. Significant differences between substrates, composting with sawdust mixing affected to a greater response for the variables height 4.61 m, 2.1 cm thick of stem, the fruits of greater weight 107.8 g, yield per plant and 4 kg and 25 kg/m-2. However, the number of flowers and clusters was higher in the sawdust substrate, so the composting with sawdust mixture may be a viable option for greenhouse tomato production.

Energy metrics of photovoltaic/thermal and earth air heat exchanger integrated greenhouse for different climatic conditions of India

Energy Technology Data Exchange (ETDEWEB)

Nayak, Sujata; Tiwari, G.N. [Centre for Energy Studies, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016 (India)

2010-10-15

In this paper, a study is carried out to evaluate the annual thermal and exergy performance of a photovoltaic/thermal (PV/T) and earth air heat exchanger (EAHE) system, integrated with a greenhouse, located at IIT Delhi, India, for different climatic conditions of Srinagar, Mumbai, Jodhpur, New Delhi and Bangalore. A comparison is made of various energy metrics, such as energy payback time (EPBT), electricity production factor (EPF) and life cycle conversion efficiency (LCCE) of the system by considering four weather conditions (a-d type) for five climatic zones. The embodied energy and annual energy outputs have been used for evaluation of the energy metrics. The annual overall thermal energy, annual electrical energy savings and annual exergy was found to be best for the climatic condition of Jodhpur at 29,156.8 kWh, 1185 kWh and 1366.4 kWh, respectively when compared with other weather stations covered in the study, due to higher solar intensity I and sunshine hours, and is lowest for Srinagar station. The results also showed that energy payback time for Jodhpur station is lowest at 16.7 years and highest for Srinagar station at 21.6 years. Electricity production factor (EPF) is highest for Jodhpur, i.e. 2.04 and Life cycle conversion efficiency (LCCE) is highest for Srinagar station. It is also observed that LCCE increases with increase in life cycle. (author)

Analysis of polymer/oxide interfaces under ambient conditions - An experimental perspective

Science.gov (United States)

González-Orive, A.; Giner, I.; de los Arcos, T.; Keller, A.; Grundmeier, G.

2018-06-01

In many different hybrid materials and materials composites polymers adhere to bulk oxides or oxide covered metal. The formed polymer/oxide interfaces are of crucial importance for the functionality and durability of such complex materials. Especially, under humid and corrosive conditions such interfaces tend to degrade due to permeability of polymers for water, the high adsorption energy of water on oxide surfaces and even corrosion processes of the metal. Different experimental studies considered such interfaces ranging from spectroscopy to electrochemical analysis. However, it is still a challenge to understand the complex interaction especially under non-ideal ambient conditions. The perspective article presents an overview on the existing experimental approaches and considers most recent experimental developments with regard to their potential applications in the area of polymer/oxide interfaces in the future.

Greenhouse effect: A first estimation of the emissions in Italy

International Nuclear Information System (INIS)

Gaudioso, D.; Onufrio, G.

1991-03-01

The estimate of the anthropogenic emissions of greenhouse gases and the selection of the relevant emission factors represents a preliminary condition to define policies aiming at curbing these emissions. In the first part of this paper there is an analysis of C0 2 emission factors, referred to the various fuels and energy technologies. The values at issue take into account the physico-chemical composition of the different fossil fuels, as well as the overall efficiency of energy production cycles and end uses patterns. As concerns the other greenhouse gases, the available information is summarized at a much more integrate level. The second part presents some estimates of carbon dioxide emissions in Italy, by sector and by fuel; some characteristic levels of specific emissions are also identified. A comparative estimate for CH 4 , N 2 O, CO and CFC's is also made, in order to set up a first reference table of the emissions of greenhouse gases in our country. (author)

Experimental characterization of gasoline sprays under highly evaporating conditions

Science.gov (United States)

Khan, Muhammad Mahabat; Sheikh, Nadeem Ahmed; Khalid, Azfar; Lughmani, Waqas Akbar

2018-05-01

An experimental investigation of multistream gasoline sprays under highly evaporating conditions is carried out in this paper. Temperature increase of fuel and low engine pressure could lead to flash boiling. The spray shape is normally modified significantly under flash boiling conditions. The spray plumes expansion along with reduction in the axial momentum causes the jets to merge and creates a low-pressure area below the injector's nozzle. These effects initiate the collapse of spray cone and lead to the formation of a single jet plume or a big cluster like structure. The collapsing sprays reduces exposed surface and therefore they last longer and subsequently penetrate more. Spray plume momentum increase, jet plume reduction and spray target widening could delay or prevent the closure condition and limit the penetration (delayed formation of the cluster promotes evaporation). These spray characteristics are investigated experimentally using shadowgraphy, for five and six hole injectors, under various boundary conditions. Six hole injectors produce more collapsing sprays in comparison to five hole injector due to enhanced jet to jet interactions. The spray collapse tendency reduces with increase in injection pressure due high axial momentum of spray plumes. The spray evaporation rates of five hole injector are observed to be higher than six hole injectors. Larger spray cone angles of the six hole injectors promote less penetrating and less collapsing sprays.

Observational determination of the greenhouse effect

Science.gov (United States)

Raval, A.; Ramanathan, V.

1989-01-01

Satellite measurements are used to quantify the atmospheric greenhouse effect, defined here as the infrared radiation energy trapped by atmospheric gases and clouds. The greenhouse effect is found to increase significantly with sea surface temperature. The rate of increase gives compelling evidence for the positive feedback between surface temperature, water vapor and the greenhouse effect; the magnitude of the feedback is consistent with that predicted by climate models. This study demonstrates an effective method for directly monitoring, from space, future changes in the greenhouse effect.

Nuclear energy and greenhouse effect

International Nuclear Information System (INIS)

Strub, R.A.

1991-01-01

The contribution of nuclear power plants against the greenhouse effects is evaluated, not only nuclear energy is unable to fight greenhouse effect increase but long life wastes endanger environment. 8 refs

Assessment of relevant factors and relationships concerning human dermal exposure to pesticides in greenhouse applications.

Science.gov (United States)

Martínez Vidal, Jose L; Egea González, Francisco J; Garrido Frenich, Antonia; Martínez Galera, María; Aguilera, Pedro A; López Carrique, Enrique

2002-08-01

Principal component analysis (PCA) was applied to the gas chromatographic data obtained from 23 different greenhouse trials. This was used to establish which factors, including application technique (very small, small, medium and large drop-size), crop characteristics (short/tall, thin/dense) and pattern application of the operator (walking towards or away from the treated area) are relevant to the dermal exposure levels of greenhouse applicators. The results showed that the highest exposure by pesticides during field applications in greenhouses, in the climatic conditions and in the crop conditions typical of a southern European country, occurs on the lower legs and front thighs of the applicators. Similar results were obtained by hierarchical cluster analysis (HCA). Drop-size seems to be very important in determining total exposure, while height and density of crops have little influence on total exposure under the conditions of the present study. No pesticide type is a major factor in total exposure. The application of multiple regression analysis (MRA) allowed assessment of the relationships between the pesticide exposure of the less affected parts of the body with the most affected parts.

Economic growth and greenhouse gas emissions

Energy Technology Data Exchange (ETDEWEB)

Ansuategi, Alberto [Environment Department, University of York, York (United Kingdom); Escapa, Marta [Foundations of Economic Analysis Department, University of the Basque Country, Bilbao (Spain)

2002-01-01

Recent empirical research has examined the relationship between certain indicators of environmental degradation and income, concluding that in some cases an inverted U-shaped relationship, which has been called an environmental Kuznets curve (EKC), exists between these variables. Unfortunately, this inverted U-shaped relationship does not hold for greenhouse gas emissions. One explanation of the absence of EKC-like behavior in greenhouse gas emissions is that greenhouse gases are special pollutants that create global, not local, disutility. But the international nature of global warming is not the only reason that prevents de-linking greenhouse gas emissions from economic growth. The intergenerational nature of the negative impact of greenhouse gas emissions may have also been an important factor preventing the implementation of greenhouse gas abatement measures in the past. In this paper we explore the effect that the presence of intergenerational spillovers has on the emissions-income relationship. We use a numerically calibrated overlapping generations model of climate-economy interactions. We conclude that: (1) the intertemporal responsibility of the regulatory agency, (2) the institutional capacity to make intergenerational transfers and (3) the presence of intergenerationally lagged impact of emissions constitute important determinants of the relationship between economic growth and greenhouse gas emissions.

Greenhouse Gas Data Publication Tool

Data.gov (United States)

U.S. Environmental Protection Agency — This tool to gives you access to greenhouse gas data reported to EPA by large facilities and suppliers in the United States through EPA's Greenhouse Gas Reporting...

The greenhouse effect gases

International Nuclear Information System (INIS)

2006-06-01

This road-map proposes by the Group Total aims to inform the public on the greenhouse effect gases. It presents the greenhouses effect as a key component of the climate system, the impacts of the human activity, the foreseeable consequences of global warming, the Kyoto protocol and Total commitment in the domain. (A.L.B.)

Monitoring and energetic performance of two similar semi-closed greenhouse ventilation systems

International Nuclear Information System (INIS)

Coomans, Mathias; Allaerts, Koen; Wittemans, Lieve; Pinxteren, Dave

2013-01-01

Highlights: • Measurements on two semi-closed greenhouses and two traditional open greenhouses. • Mechanical and natural ventilation for dehumidification and cooling. • Analyses and comparison of installation controls, indoor climate and energy flows. • Examination of air-to-air heat recuperation efficiency in ventilation unit. • Using the semi-closed systems amounted to energy savings of 13% and 28%. - Abstract: Horticulture is an energy intensive industry when dealing with cold climates such as Western Europe. High energy prices and on-going pressure from international competition are raising demand for energy efficient solutions. In search of reducing greenhouse energy consumption, this study investigates semi-closed systems combining controlled mechanical and natural ventilation with thermal screens. Ventilated greenhouse systems (semi-closed) have been implemented in the greenhouse compartments of two Belgian horticulture research facilities: the Research Station for Vegetable Production Sint-Katelijne-Waver (PSKW) and the Research Center Hoogstraten (PCH). Additionally, two reference compartments were included for comparison of the results. The greenhouses were part of a long-term monitoring campaign in which detailed measurements with a high time resolution were gathered by a central monitoring system. A large amount of data was processed and analysed, including outdoor and indoor climatic parameters, system controls and installation measurements. The ventilated greenhouses obtained energy savings of 13% and 28% for PSKW and PCH respectively, without substantial impact on crop production or indoor climate conditions when compared to the reference compartments. A considerable amount of heat was recovered by the heat recuperation stage in the ventilation unit of PCH, accounting for 12% of the total heat demand. In general, it was demonstrated that the greenhouse heat demand can be reduced significantly by controlled dehumidification with mechanical

Deep percolation in greenhouse-cultivated celery using the technique of subsurface film strips placement

Directory of Open Access Journals (Sweden)

Zhida Du

2014-05-01

Full Text Available To reduce the deep percolation during greenhouse vegetable cultivation, the technique of subsurface film strips placement was tested. Four treatments with two kinds of cross-sections (flat and U-shaped and two different spacings (10 cm and 40 cm of subsurface film strips were arranged in a greenhouse before planting celery. At the same time, a non-film treatment was arranged for comparison. Soil water content was measured and irrigation time was adjusted according to the soil water content. Evapotranspiration of celery during growth was calculated by the method of energy balance and the deep percolation was calculated by the equation of water balance. Deep percolation was reduced in all experimental treatments. Greater reduction in deep percolation was observed when using U-shaped cross-section strips compared with that using the flat cross-section strips. In addition, greater reduction in deep percolation was observed when the spacing between the film strips was smaller. The results of this test showed that the technique of subsurface film strips placement can reduce deep percolation and conserve irrigation water for greenhouse vegetables cultivation. However, the optimal layout variables for the use of the technique of subsurface film strips placement need further experimental and numerical analysis.

UNEP greenhouse gas abatement costing studies

International Nuclear Information System (INIS)

Maya, R.S.; Nziramasanga, N.; Muguti, E.; Fenhann, J.

1993-10-01

The aim was to assess options and cost of reducing emissions of greenhouse gases (with emphasis on carbon dioxide) from human activity in Zimbabwe. A brief description of the country's economy and energy sector, policy and pricing and regulations is given and substantial data related to the country's economy, technology, energy consumption, emission and fuel prices are presented. The energy demand in households and for other sectors in Zimbabwe are assessed, and documented in the case of the former. The reference scenarios on energy demand and supply assess greenhouse gas emissions under conditions whereby the present economic growth trends predominate. Energy efficiency improvements are discussed. Abatement technology options are stated as afforestation for carbon sequestration, more efficient coal-fired industrial boilers, extended use of hydroelectricity, prepayment electric meters, minimum tillage, optimization of coal-fired tobacco barns, industrial power factor correction equipment, domestic biogas digesters, solar water heating systems, time switches in electric geysers, optimization of industrial furnaces, photovoltaic water pumps, production of ammonia from coal for fertilizing purposes, and recovery of coke oven gases for use in thermal power generation. (AB)

Ethylene emission and PR protein synthesis in ACC deaminase producing Methylobacterium spp. inoculated tomato plants (Lycopersicon esculentum Mill.) challenged with Ralstonia solanacearum under greenhouse conditions.

Science.gov (United States)

Yim, Woojong; Seshadri, Sundaram; Kim, Kiyoon; Lee, Gillseung; Sa, Tongmin

2013-06-01

Bacteria of genus Methylobacterium have been found to promote plant growth and regulate the level of ethylene in crop plants. This work is aimed to test the induction of defense responses in tomato against bacterial wilt by stress ethylene level reduction mediated by the ACC deaminase activity of Methylobacterium strains. Under greenhouse conditions, the disease index value in Methylobacterium sp. inoculated tomato plants was lower than control plants. Plants treated with Methylobacterium sp. challenge inoculated with Ralstonia solanacearum (RS) showed significantly reduced disease symptoms and lowered ethylene emission under greenhouse condition. The ACC and ACO (1-aminocyclopropane-1-carboxylate oxidase) accumulation in tomato leaves were significantly reduced with Methylobacterium strains inoculation. While ACC oxidase gene expression was found higher in plants treated with R. solanacearum than Methylobacterium sp. treatment, PR proteins related to induced systemic resistance like β-1,3-glucanase, PAL, PO and PPO were increased in Methylobacterium sp. inoculated plants. A significant increase in β-1,3-glucanase and PAL gene expression was found in all the Methylobacterium spp. treatments compared to the R. solanacearum treatment. This study confirms the activity of Methylobacterium sp. in increasing the defense enzymes by modulating the ethylene biosynthesis pathway and suggests the use of methylotrophic bacteria as potential biocontrol agents in tomato cultivation. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Design and Concept of an Energy System Based on Renewable Sources for Greenhouse Sustainable Agriculture

Directory of Open Access Journals (Sweden)

Ioan Aschilean

2018-05-01

Full Text Available Bio-organic greenhouses that are based on alternative resources for producing heat and electricity stand out as an efficient option for the sustainable development of agriculture, thus ensuring good growth and development of plants in all seasons, especially during the cold season. Greenhouses can be used with maximum efficiency in various agricultural lands, providing ideal conditions of temperature and humidity for short-term plant growing, thereby increasing the local production of fruit and vegetables. This paper presents the development of a durable greenhouse concept that is based on complex energy system integrating fuel cells and solar panels. Approaching this innovative concept encountered a major problem in terms of local implementation of this type of greenhouses because of the difficulty in providing electrical and thermal energy from conventional sources to ensure an optimal climate for plant growing. The project result consists in the design and implementation of a sustainable greenhouse energy system that is based on fuel cells and solar panels.

Middle-School Understanding of the Greenhouse Effect using a NetLogo Computer Model

Science.gov (United States)

Schultz, L.; Koons, P. O.; Schauffler, M.

2009-12-01

We investigated the effectiveness of a freely available agent based, modeling program as a learning tool for seventh and eighth grade students to explore the greenhouse effect without added curriculum. The investigation was conducted at two Maine middle-schools with 136 seventh-grade students and 11 eighth-grade students in eight classes. Students were given a pre-test that consisted of a concept map, a free-response question, and multiple-choice questions about how the greenhouse effect influences the Earth's temperature. The computer model simulates the greenhouse effect and allows students to manipulate atmospheric and surface conditions to observe the effects on the Earth’s temperature. Students explored the Greenhouse Effect model for approximately twenty minutes with only two focus questions for guidance. After the exploration period, students were given a post-test that was identical to the pre-test. Parametric post-test analysis of the assessments indicated middle-school students gained in their understanding about how the greenhouse effect influences the Earth's temperature after exploring the computer model for approximately twenty minutes. The magnitude of the changes in pre- and post-test concept map and free-response scores were small (average free-response post-test score of 7.0) compared to an expert's score (48), indicating that students understood only a few of the system relationships. While students gained in their understanding about the greenhouse effect, there was evidence that students held onto their misconceptions that (1) carbon dioxide in the atmosphere deteriorates the ozone layer, (2) the greenhouse effect is a result of humans burning fossil fuels, and (3) infrared and visible light have similar behaviors with greenhouse gases. We recommend using the Greenhouse Effect computer model with guided inquiry to focus students’ investigations on the system relationships in the model.

The Semitransparent Photovoltaic Films for Mediterranean Greenhouse: A New Sustainable Technology

Directory of Open Access Journals (Sweden)

Alvaro Marucci

2012-01-01

Full Text Available Mediterranean countries offer very favorable climatic conditions for growing plants in a protected environment: as a matter of fact, the high solar radiation allows the use of greenhouses with simple structures, covered with plastic film and without fixed installations for winter heating. They are called “Mediterranean greenhouses” and are totally different from those in Central and Northern Europe. In the photovoltaic greenhouses, the cover on the pitch facing south is usually replaced by very opaque panels. However, this solution compromises the possibility to grow plants in covered and protected environments since solar radiation availability is limited and strongly nonuniform. In order to overcome this problem, semitransparent photovoltaic materials can be used to let the solar energy, necessary for plant growth, pass into the green house. The aim of this research is to analyze the radiometric properties of innovative semitransparent flexible photovoltaic materials in order to evaluate their performances in comparison with materials commonly used in the coverage of the greenhouses. Particular attention is paid to the transmittance of these materials in the visible range and in the long wave infrared for the achievement of greenhouse effect.

Greenhouse Module for Space System: A Lunar Greenhouse Design

Directory of Open Access Journals (Sweden)

Zeidler Conrad

2017-02-01

Full Text Available In the next 10 to 20 years humankind will return to the Moon and/or travel to Mars. It is likely that astronauts will eventually build permanent settlements there, as a base for long-term crew tended research tasks. It is obvious that the crew of such settlements will need food to survive. With current mission architectures the provision of food for longduration missions away from Earth requires a significant number of resupply flights. Furthermore, it would be infeasible to provide the crew with continuous access to fresh produce, specifically crops with high water content such as tomatoes and peppers, on account of their limited shelf life. A greenhouse as an integrated part of a planetary surface base would be one solution to solve this challenge for long-duration missions. Astronauts could grow their own fresh fruit and vegetables in-situ to be more independent from supply from Earth. This paper presents the results of the design project for such a greenhouse, which was carried out by DLR and its partners within the framework of the Micro-Ecological Life Support System Alternative (MELiSSA program. The consortium performed an extensive system analysis followed by a definition of system and subsystem requirements for greenhouse modules. Over 270 requirements were defined in this process. Afterwards the consortium performed an in-depth analysis of illumination strategies, potential growth accommodations and shapes for the external structure. Five different options for the outer shape were investigated, each of them with a set of possible internal configurations. Using the Analytical Hierarchy Process, the different concept options were evaluated and ranked against each other. The design option with the highest ranking was an inflatable outer structure with a rigid inner core, in which the subsystems are mounted. The inflatable shell is wrapped around the core during launch and transit to the lunar surface. The paper provides an overview of the

Preliminary design of a low-cost greenhouse for salt production in Indonesia

Science.gov (United States)

Jaziri, A. A.; Guntur; Setiawan, W.; Prihanto, A. A.; Kurniawan, A.

2018-04-01

Salt is an assential material of industry, not only in food industry point of view but also in various industries such as chemical, oil drilling, and animal feed industries, even less than half of salt needs used to household consumption. It is crucial to ensure salt production in Indonesia reaches the national target (3.7 million tons) due to relatively low technology and production level. Thus salt production technology is developed to facilitate farmers consisted of geomembrane and filtering-threaded technology. However, the use of those technologies in producing salt was proved less effective due to unpredictable weather conditions. Therefore, greenhouse technology is proposed to be used for salt production for several good reasons. This paper describes the preliminary design of a low-cost greenhouse designed as a pyramid model that uses bamboo, mono-layer and high density polyethylene plastics. The results confirmed that the yield of salt produced by greenhouse significantly incresed compared with prior technology and the NaCl content increased as well. The cost of greenhouse was IDR 5,688,000 and easy to assembly.

Development of bioengineering processes to transform greenhouse waste into energy, fertilizer and tomato

Energy Technology Data Exchange (ETDEWEB)

Brisson, D.; Masse, D.I. [Agriculture and Agri-Food Canada, Lennoxville, PQ (Canada). Dairy and Swine Research and Development Centre; Juteau, P. [Quebec Univ., Laval, PQ (Canada). INRS-Institut Armand Frappier; Saint-Laurent CEGEP, Montreal, PQ (Canada). Centre des technologies de l' eau; Dorais, M. [Agriculture and Agri-Food Canada, Quebec City, PQ (Canada). Horticultural Research Centre

2010-07-01

Methods to promote sustainable production systems in greenhouses were discussed with particular reference to anaerobic digestion (AD) and nitrification processes for waste and nutrient management and energy consumption. The high cost of organic soluble fertilizers and the difficulty in obtaining a quality product are strong limitations for converting conventional greenhouses to organic practices. AD has been shown to be a promising solution for disposal of tomato leaves pruned during greenhouse operations. Studies have shown that AD generates end-products, notably supernatant sludge that have agronomic benefits of land application for forage and cereal crops. However, little has been done for horticultural crops. Unlike field crops, nitrification of digester effluents is a key step for using AD effluents as fertilizers for vegetable greenhouse plants. Greenhouse vegetables need nitrogen mainly under the nitrate form for an adequate growth because the other forms of nitrogen are detrimental to plant and fruit quality. However, nitrification of AD supernatant can be challenging because of its high ammonia content and its inhibition potential of nitrifying micro-organisms. This study examined the few nitrification processes that have the potential to operate under these conditions.

Review of optimum temperature, humidity, and vapour pressure deficit for microclimate evaluation and control in greenhouse cultivation of tomato: a review

Science.gov (United States)

Shamshiri, Redmond Ramin; Jones, James W.; Thorp, Kelly R.; Ahmad, Desa; Man, Hasfalina Che; Taheri, Sima

2018-04-01

Greenhouse technology is a flexible solution for sustainable year-round cultivation of Tomato (Lycopersicon esculentum Mill), particularly in regions with adverse climate conditions or limited land and resources. Accurate knowledge about plant requirements at different growth stages, and under various light conditions, can contribute to the design of adaptive control strategies for a more cost-effective and competitive production. In this context, different scientific publications have recommended different values of microclimate parameters at different tomato growth stages. This paper provides a detailed summary of optimal, marginal and failure air and root-zone temperatures, relative humidity and vapour pressure deficit for successful greenhouse cultivation of tomato. Graphical representations of the membership function model to define the optimality degrees of these three parameters are included with a view to determining how close the greenhouse microclimate is to the optimal condition. Several production constraints have also been discussed to highlight the short and long-term effects of adverse microclimate conditions on the quality and yield of tomato, which are associated with interactions between suboptimal parameters, greenhouse environment and growth responses.

Study of soil-plant transfer of 226Ra under greenhouse conditions

International Nuclear Information System (INIS)

Soudek, Petr; Petrova, Sarka; Benesova, Dagmar; Kotyza, Jan; Vagner, Martin; Vankova, Radomira; Vanek, Tomas

2010-01-01

A soil-plant transfer study was performed using soil from a former uranium ore processing factory in South Bohemia. We present the results from greenhouse experiments which include estimates of the time required for phytoremediation. The accumulation of 226 Ra by different plant species from a mixture of garden soil and contaminated substrate was extremely variable, ranging from 0.03 to 2.20 Bq 226 Ra/g DW. We found differences in accumulation of 226 Ra between plants from the same genus and between cultivars of the same plant species. The results of 226 Ra accumulation showed a linear relation between concentration of 226 Ra in plants and concentration of 226 Ra in soil mixtures. On the basis of these results we estimated the time required for phytoremediation, but this appears to be too long for practical purposes.

The greenhouse effect. Drivhuseffekten; Jordens atmosfaere og magnetfelt

Energy Technology Data Exchange (ETDEWEB)

Egeland, A; Henriksen, T [Oslo Univ., Fysisk Inst. (Norway); Kanestroem, I [Oslo Univ., Inst. for Geofysikk (Norway)

1990-01-01

This book deals with what is popularly called ''the greenhouse effect''. The starting point is the sun, and it is considered how the atmosphere and magnetic field of the earth protect us against the radiation from the outer space. The atmosphere contains gases in a quantity and a mixture that make conditions suitable for the life on the earth. We are dependent on the existing greenhouse effect, but are anxious that the emitted gases caused by human activities, will increase the temperature in an alarming degree. The book is addressed to all who have an interest in the nature and the environment. It may be used in colleges and in courses for environmental studies. It gives information to politicians and other people who have to make decisions in the management of the nature and the resources of the earth. 70 figs., 15 tabs.

Regional greenhouse gas emissions from cultivation of winter wheat and winter rapeseed for biofuels in Denmark

DEFF Research Database (Denmark)

Elsgaard, Lars; Olesen, Jørgen E; Hermansen, John Erik

2013-01-01

Biofuels from bioenergy crops may substitute a significant part of fossil fuels in the transport sector where, e.g., the European Union has set a target of using 10% renewable energy by 2020. Savings of greenhouse gas emissions by biofuels vary according to cropping systems and are influenced...... by such regional factors as soil conditions, climate and input of agrochemicals. Here we analysed at a regional scale the greenhouse gas (GHG) emissions associated with cultivation of winter wheat for bioethanol and winter rapeseed for rapeseed methyl ester (RME) under Danish conditions. Emitted CO2 equivalents...

The Runaway Greenhouse Effect on Earth and other Planets

Science.gov (United States)

Rabbette, Maura; Pilewskie, Peter; McKay, Christopher; Young, Robert

2001-01-01

Water vapor is an efficient absorber of outgoing longwave infrared radiation on Earth and is the primary greenhouse gas. Since evaporation increases with increasing sea surface temperature, and the increase in water vapor further increases greenhouse warming, there is a positive feedback. The runaway greenhouse effect occurs if this feedback continues unchecked until all the water has left the surface and enters the atmosphere. For Mars and the Earth the runaway greenhouse was halted when water vapor became saturated with respect to ice or liquid water respectively. However, Venus is considered to be an example of a planet where the runaway greenhouse effect did occur, and it has been speculated that if the solar luminosity were to increase above a certain limit, it would also occur on the Earth. Satellite data acquired during the Earth Radiation Budget Experiment (ERBE) under clear sky conditions shows that as the sea surface temperature (SST) increases, the rate of outgoing infrared radiation at the top of the atmosphere also increases, as expected. Over the pacific warm pool where the SST exceeds 300 K the outgoing radiation emitted to space actually decreases with increasing SST, leading to a potentially unstable system. This behavior is a signature of the runaway greenhouse effect on Earth. However, the SST never exceeds 303K, thus the system has a natural cap which stops the runaway. According to Stefan-Boltzmann's law the amount of heat energy radiated by the Earth's surface is proportional to (T(sup 4)). However, if the planet has a substantial atmosphere, it can absorb all infrared radiation from the lower surface before the radiation penetrates into outer space. Thus, an instrument in space looking at the planet does not detect radiation from the surface. The radiation it sees comes from some level higher up. For the earth#s atmosphere the effective temperature (T(sub e)) has a value of 255 K corresponding to the middle troposphere, above most of the

A New Strategy in Observer Modeling for Greenhouse Cucumber Seedling Growth

Science.gov (United States)

Qiu, Quan; Zheng, Chenfei; Wang, Wenping; Qiao, Xiaojun; Bai, He; Yu, Jingquan; Shi, Kai

2017-01-01

State observer is an essential component in computerized control loops for greenhouse-crop systems. However, the current accomplishments of observer modeling for greenhouse-crop systems mainly focus on mass/energy balance, ignoring physiological responses of crops. As a result, state observers for crop physiological responses are rarely developed, and control operations are typically made based on experience rather than actual crop requirements. In addition, existing observer models require a large number of parameters, leading to heavy computational load and poor application feasibility. To address these problems, we present a new state observer modeling strategy that takes both environmental information and crop physiological responses into consideration during the observer modeling process. Using greenhouse cucumber seedlings as an instance, we sample 10 physiological parameters of cucumber seedlings at different time point during the exponential growth stage, and employ them to build growth state observers together with 8 environmental parameters. Support vector machine (SVM) acts as the mathematical tool for observer modeling. Canonical correlation analysis (CCA) is used to select the dominant environmental and physiological parameters in the modeling process. With the dominant parameters, simplified observer models are built and tested. We conduct contrast experiments with different input parameter combinations on simplified and un-simplified observers. Experimental results indicate that physiological information can improve the prediction accuracies of the growth state observers. Furthermore, the simplified observer models can give equivalent or even better performance than the un-simplified ones, which verifies the feasibility of CCA. The current study can enable state observers to reflect crop requirements and make them feasible for applications with simplified shapes, which is significant for developing intelligent greenhouse control systems for modern

A New Strategy in Observer Modeling for Greenhouse Cucumber Seedling Growth

Directory of Open Access Journals (Sweden)

Quan Qiu

2017-08-01

Full Text Available State observer is an essential component in computerized control loops for greenhouse-crop systems. However, the current accomplishments of observer modeling for greenhouse-crop systems mainly focus on mass/energy balance, ignoring physiological responses of crops. As a result, state observers for crop physiological responses are rarely developed, and control operations are typically made based on experience rather than actual crop requirements. In addition, existing observer models require a large number of parameters, leading to heavy computational load and poor application feasibility. To address these problems, we present a new state observer modeling strategy that takes both environmental information and crop physiological responses into consideration during the observer modeling process. Using greenhouse cucumber seedlings as an instance, we sample 10 physiological parameters of cucumber seedlings at different time point during the exponential growth stage, and employ them to build growth state observers together with 8 environmental parameters. Support vector machine (SVM acts as the mathematical tool for observer modeling. Canonical correlation analysis (CCA is used to select the dominant environmental and physiological parameters in the modeling process. With the dominant parameters, simplified observer models are built and tested. We conduct contrast experiments with different input parameter combinations on simplified and un-simplified observers. Experimental results indicate that physiological information can improve the prediction accuracies of the growth state observers. Furthermore, the simplified observer models can give equivalent or even better performance than the un-simplified ones, which verifies the feasibility of CCA. The current study can enable state observers to reflect crop requirements and make them feasible for applications with simplified shapes, which is significant for developing intelligent greenhouse control

A New Strategy in Observer Modeling for Greenhouse Cucumber Seedling Growth.

Science.gov (United States)

Qiu, Quan; Zheng, Chenfei; Wang, Wenping; Qiao, Xiaojun; Bai, He; Yu, Jingquan; Shi, Kai

2017-01-01

State observer is an essential component in computerized control loops for greenhouse-crop systems. However, the current accomplishments of observer modeling for greenhouse-crop systems mainly focus on mass/energy balance, ignoring physiological responses of crops. As a result, state observers for crop physiological responses are rarely developed, and control operations are typically made based on experience rather than actual crop requirements. In addition, existing observer models require a large number of parameters, leading to heavy computational load and poor application feasibility. To address these problems, we present a new state observer modeling strategy that takes both environmental information and crop physiological responses into consideration during the observer modeling process. Using greenhouse cucumber seedlings as an instance, we sample 10 physiological parameters of cucumber seedlings at different time point during the exponential growth stage, and employ them to build growth state observers together with 8 environmental parameters. Support vector machine (SVM) acts as the mathematical tool for observer modeling. Canonical correlation analysis (CCA) is used to select the dominant environmental and physiological parameters in the modeling process. With the dominant parameters, simplified observer models are built and tested. We conduct contrast experiments with different input parameter combinations on simplified and un-simplified observers. Experimental results indicate that physiological information can improve the prediction accuracies of the growth state observers. Furthermore, the simplified observer models can give equivalent or even better performance than the un-simplified ones, which verifies the feasibility of CCA. The current study can enable state observers to reflect crop requirements and make them feasible for applications with simplified shapes, which is significant for developing intelligent greenhouse control systems for modern

Greenhouse effect of NO{sub x}

Energy Technology Data Exchange (ETDEWEB)

Lammel, G; Grassl, H [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany)

1995-07-01

Through various processes the nitrogen oxides (NO{sub x}) interact with trace gases in the troposphere and stratosphere which do absorb in the spectral range relevant to the greenhouse effect (infrared wavelengths). The net effect is an enhancement of the greenhouse effect. The catalytic role of NO{sub x} in the production of tropospheric ozone provides the most prominent contribution. The global waming potential is estimated as GWP (NO{sub x}) = 30-33 and 7-10 for the respective time horizons of 20 and 100 years, and is thereby comparable to that of methane. NO{sub x} emissions in rural areas of anthropogenically influenced regions, or those in the vicinity of the tropopause caused by air traffic, cause the greenhouse effectivity to be substantially more intense. We estimate an additional 5-23% for Germany`s contribution to the anthropogenic greenhouse effect as a result of the indirect greenhouse effects stemming from NO{sub x}. Furthermore, a small and still inaccurately defined amount of the deposited NO{sub x} which has primarily been converted into nitrates is again released from the soil into the atmosphere in the form of the long-lived greenhouse gas nitrous oxide (N{sub i}O). Thus, anthropogenically induced NO{sub x} emissions contribute to enhanced greenhouse effect and to stratospheric ozone depletion in the time scale of more than a century. (orig.)

Harnessing greenhouse effect

International Nuclear Information System (INIS)

Meunier, F.; Rivet, P.; Terrier, M.F.

2005-01-01

This book considers the energy and greenhouse effect questions in a global way. It presents the different methods of fight against the increase of the greenhouse effect (energy saving, carbon sinks, cogeneration,..), describes the main alternative energy sources to fossil fuels (biomass, wind power, solar, nuclear,..), and shows that, even worrying, the future is not so dark as it seems to be and that technical solutions exist which will allow to answer the worldwide growing up energy needs and to slow down the climatic drift. (J.S.)

75 FR 57669 - Mandatory Reporting of Greenhouse Gases

Science.gov (United States)

2010-09-22

... Mandatory Reporting of Greenhouse Gases AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: This action amends the Final Mandatory Reporting of Greenhouse Gases Rule to require reporters... Numbers GHG greenhouse gas GHGRP Greenhouse Gas Reporting Program HCFC hydrochlorofluorocarbon HFC...

Modeling and parametric studies for thermal performance of an earth to air heat exchanger integrated with a greenhouse

International Nuclear Information System (INIS)

Ghosal, M.K.; Tiwari, G.N.

2006-01-01

A thermal model has been developed to investigate the potential of using the stored thermal energy of the ground for greenhouse heating and cooling with the help of an earth to air heat exchanger (EAHE) system integrated with the greenhouse located in the premises of IIT, Delhi, India. Experiments were conducted extensively throughout the year 2003, but the developed model was validated against typical clear and sunny days experiments. Parametric studies performed for the EAHE coupled with the greenhouse illustrate the effects of buried pipe length, pipe diameter, mass flow rate of air, depth of ground and types of soil on the greenhouse air temperatures. The temperatures of the greenhouse air, with the experimental parameters of the EAHE, were found to be, on average 7-8 deg. C higher in the winter and 5-6 deg. C lower in the summer than those of the same greenhouse without the EAHE. The greenhouse air temperatures increase in the winter and decrease in the summer with increasing pipe length, decreasing pipe diameter, decreasing mass flow rate of flowing air inside buried pipe and increasing depth of ground up to 4 m. The predicted and measured values of the greenhouse air temperatures that were verified, in terms of root mean square percent deviation and correlation coefficient, exhibited fair agreement

Greenhouse production systems for people

NARCIS (Netherlands)

Giacomelli, G.A.; Sase, S.; Cramer, R.; Hoogeboom, J.; McKenzie, A.; Parbst, K.; Sacrascia-Mugnozza, G.; Selina, P.; Sharp, D.A.; Voogt, J.O.; Weel, van P.A.; Mears, D.

2012-01-01

Environmentally sound greenhouse production requires that: demand for market products is understood; greenhouse design addresses the climate circum-stances; input resources are available and consumed efficiently, and; there must be a reasonable balance of production products to the environmental

The Effects of Biological Fertilizers, Chemical Fertilizers and Manure Application on Some Qualitative Characteristics of Vicia villosa Roth Forage under Greenhouse Condition

Directory of Open Access Journals (Sweden)

R Kamaei

2017-03-01

Full Text Available Introduction Fertilizer management plays an important role in successful crop production. The biological fertilizers have been suggested not only to elimination or significant reduction of chemical fertilizer dependency but also increase of soil fertility and improvement of crop yield and quality. Materials and Methods This experiment was conducted in a completely randomized design with three replications at the Research Greenhouse of Ferdowsi University of Mashhad. The experimental treatments included 1- mycorrhizae arbuscular (Glomus mosseae, 2- mycorrhizae arbuscular (Glomus mosseae + vermicompost (M+V, 3- mycorrhizae + nitroxein (included bacteria Azospirillum sp. and Azotobacter sp. (M+N, 4- mycorrhizae arbuscular + Rhizobium (R. legominuzarum (M+R, 5-mycorrhizae arbuscular + NPK Chemical fertilizer (40-40-20 (M+NPK and 6- Control (without fertilizer, C. In bio-fertilizer treatments, seeds were inoculated by mycorrhizae and Rhizobium immediately before planting, according the standard conditions and company recommendations. Chemical fertilizer and vermicompost were applied directly into the soil. The first irrigation was done immediately after planting and an additional irrigation was also done 4 days after planting to improve the seedling emergence. Subsequent irrigations were conducted at 10-days interval. Forage samples were collected at stage of 10% open bud. The samples were oven-dried in 70°C for 48 h and then weighed before being ground to pass through a 1-mm sieve. Both chemical analysis and in vitro digestibility assessments were performed in triplicate. Crud protein (CP, Ash, neutral detergent fiber (NDF and acid detergent fiber (ADF content of forages were measured by standard methods. An in vitro gas production method was conducted to determine the dry matter (DM and organic matter (OM digestibility. All data were subjected to ANOVA using the GLM procedure of SAS (SAS 9.1 and means were compared by using LSD-test at 5

The effect of plant growth-promoting rhizobacteria on asparagus seedlings and germinating seeds subjected to water stress under greenhouse conditions.

Science.gov (United States)

Liddycoat, Scott M; Greenberg, Bruce M; Wolyn, David J

2009-04-01

Plant growth-promoting rhizobacteria (PGPR) can have positive effects on vigour and productivity, especially under stress conditions. In asparagus (Asparagus officinalis L.) field culture, seeds are planted in high-density nurseries, and 1-year-old crowns are transplanted to production fields. Performance can be negatively affected by water stress, transplant shock, and disease pressure on wounded roots. PGPR inoculation has the potential to alleviate some of the stresses incurred in the production system. In this study, the effects of PGPR (Pseudomonas spp.) treatment were determined on 3-week-old greenhouse-grown seedlings and germinating seeds of 2 asparagus cultivars. The pots were irrigated to a predetermined level that resulted in optimum growth or the plants were subjected to drought or flooding stress for 8 weeks. The cultivars responded differently to PGPR: single inoculations of seedlings enhanced growth of 'Guelph Millennium' under optimum conditions and 'Jersey Giant' seedlings under drought stress. Seed inoculations with PGPR resulted in a positive response only for 'Guelph Millennium', for which both single or multiple inoculations enhanced plant growth under drought stress.

Lay perceptions of the greenhouse effect

International Nuclear Information System (INIS)

Peretti-Watel, P.; Hammer, B.

2006-01-01

Using the data from the French Environment Barometer EDF-RD 2004 (national representative sample of French citizens aged over 15) and surveys by ADEME between 2000 and 2005, the paper investigates lay perceptions of the causes and consequences of the greenhouse effect, which may be considered as archetypical of contemporary environmental risks. Beyond lay lack of knowledge, the greenhouse effect gives rise to coherent and meaningful cognitions, including causal explanations, shaped by the pre-existing cognitive framework. This cognitive work, based on analogic rather than scientific thought, strings together the greenhouse effect, ozone depletion, air pollution and even nuclear power. The cognitive process is also fed by the individuals' general conceptions of Nature and of the rights and duties of humankind towards Nature. People are not greatly worried about the unseen and controversial consequences of the greenhouse effect: such worry could be one of those 'elite fears' mentioned by Beck. Finally, while the efficiency of public policies to counter the greenhouse effect requires extensive societal involvement, low confidence towards both political and scientific authorities may prevent the population from becoming aware of the environmental stakes tied to the greenhouse effect. (authors)

Thermal analysis of a hybrid solar energy saving system inside a greenhouse

International Nuclear Information System (INIS)

Ntinas, G.K.; Fragos, V.P.; Nikita-Martzopoulou, Ch.

2014-01-01

Highlights: • A hybrid solar system consisted of water filled polyethylene sleeves was examined. • The thermal behaviour of the system was studied based on the sleeves energy balance. • Water temperature and heat exchanges of the sleeves were dynamically estimated. • Experimental data used to validate the predictions of the mathematical model. • The use of the system led to an energy saving of 23% inside a heated greenhouse. - Abstract: The intensive greenhouse energy requirements are a major operational and economical problem for producers around the world. Energy conservation techniques and innovative applications of solar energy for heating are being employed in greenhouse operation to reduce heating costs during cold periods. The present study investigated the development of a mathematical model to predict the thermal efficiency of a novel hybrid solar energy saving system inside a heated greenhouse. The solar system consisted of a transparent water-filled polyethylene sleeve and two perforated air-filled polyethylene tubes on the top peripheral sides of it. Above the sleeve and between the two tubes, rockwool substrates were placed for hydroponic cultivation of tomato crop. In order to validate this model, experiments were carried out in two identical parts of a polyethylene arched-type greenhouse to obtain data during winter. By comparing the measured and the predicted values, a correlation of 95% was found, indicating that the model can simulate the water temperature inside the hybrid solar sleeves. Moreover, the additional energy provided by the hybrid solar system reached approximately 23% during the examined period, depending on solar radiation levels

Detectors for Linear Colliders: Physics Requirements and Experimental Conditions (1/4)

CERN Multimedia

CERN. Geneva

2010-01-01

How is the anticipated physics program of a future e+e- collider shaping the R&D for new detectors in collider particle physics ? This presentation will review the main physics requirements and experimental conditions comparing to LHC and LEP. In particular, I shall discuss how e+e- experimentation is expected to change moving from LEP-2 up to multi-TeV energies.

Liquid desiccant dehumidification and regeneration process to meet cooling and freshwater needs of desert greenhouses

KAUST Repository

Lefers, Ryan

2016-04-19

Agriculture accounts for ~70% of freshwater usage worldwide. Seawater desalination alone cannot meet the growing needs for irrigation and food production, particularly in hot, desert environments. Greenhouse cultivation of high-value crops uses just a fraction of freshwater per unit of food produced when compared with open field cultivation. However, desert greenhouse producers face three main challenges: freshwater supply, plant nutrient supply, and cooling of the greenhouse. The common practice of evaporative cooling for greenhouses consumes large amounts of fresh water. In Saudi Arabia, the most common greenhouse cooling schemes are fresh water-based evaporative cooling, often using fossil groundwater or energy-intensive desalinated water, and traditional refrigeration-based direct expansion cooling, largely powered by the burning of fossil fuels. The coastal deserts have ambient conditions that are seasonally too humid to support adequate evaporative cooling, necessitating additional energy consumption in the dehumidification process of refrigeration-based cooling. This project evaluates the use of a combined-system liquid desiccant dehumidifier and membrane distillation unit that can meet the dual needs of cooling and freshwater supply for a greenhouse in a hot and humid environment. © 2016 Balaban Desalination Publications. All rights reserved.

Solar greenhouse assisted biogas plant in hilly region - A field study

Energy Technology Data Exchange (ETDEWEB)

Vinoth Kumar, K.; Kasturi Bai, R. [Department of Bio-Energy, School of Energy, Environment and Natural Resources, Madurai Kamaraj University, Madurai 625 021, Tamil Nadu (India)

2008-10-15

The present study was undertaken with the objective of evaluating plastic as an alternative material for biogas plant on a par with conventional brick material. The field study was carried out for one year (October, 2005-September, 2006) in a small hamlet at Nilgiris incorporating solar energy to study its influence on biogas production. During summer (April-June) the temperature reaches to the maximum of 21-25 C and the minimum of 10-12 C. During winter (October-December), the temperature available is maximum of 16-21 C and minimum of 2 C. The solar insolation in the study area ranges from 250 to 600 W/m{sup 2}. This study involves the control conventional Deenabandhu model (Indian standard model prevailing in most part of India made of masonry structure only) and the experimental plastic tank with greenhouse canopy of similar capacity. Our previous work [Vinoth Kumar, K., Kasturi Bai, R., 2005. Plastic biodigesters - a systematic study. Energy for Sustainable Development 9 (4), 40-49] on lab scale digester made from plastic material was compared over other materials and the results gave us much confidence to carry out further study on pilot scale. In continuation, a semi-continuous study was conducted for one year with the retention time of 55 days. The gas generated from the biogas plants was utilized for cooking (burner) and lighting (lamp) purposes. The yearly average slurry temperatures recorded during the study period was 26.3 and 22.4 C in experimental and control biogas plants against ambient temperature of 17.0 C. The yearly average greenhouse chamber temperature recorded was 29.1 C in the experimental biogas plant. The yearly average gas yield from the experimental and control biogas plants were 39.1 and 34.6 l kg{sup -1}day{sup -1} respectively. Gas productions in the winter season registered lower than other months. It can be concluded that the solar greenhouse assisted plastic biogas plant can be efficiently adopted with minor modifications in hilly

Greenhouse Warming Research

DEFF Research Database (Denmark)

Sørensen, Bent Erik

2016-01-01

The changing greenhouse effect caused by natural and anthropogenic causes is explained and efforts to model the behavior of the near-surface constituents of the Earth's land, ocean and atmosphere are discussed. Emissions of various substances and other aspects of human activity influence...... the greenhouse warming, and the impacts of the warming may again impact the wellbeing of human societies. Thus physical modeling of the near-surface ocean-soil-atmosphere system cannot be carried out without an idea of the development of human activities, which is done by scenario analysis. The interactive...

Crossing the chasm in Dutch greenhouse horticulture

NARCIS (Netherlands)

Buurma, J.S.; Smit, P.X.

2016-01-01

Dutch greenhouse horticulture has an innovation and development programme called 'Kas als Energiebron' (Greenhouse as Energy Producer). The objective of this programme is reducing the carbon footprint and improving the energy efficiency of greenhouse horticulture, and developing a climate neutral

Greenhouse effect

International Nuclear Information System (INIS)

1992-01-01

This special issue is devoted to the greenhouse effect and reviews the possible climate change by mankind, paleoclimates, climate models, measurement of terrestrial temperature, CO 2 concentration and energy policy

“Walczak’s Pipes” in the Greenhouse Heating System

Directory of Open Access Journals (Sweden)

Kazimierz Rutkowski

2016-01-01

Full Text Available Diversified heating circuits inertia is particularly important by high variability of external conditions were the greenhouse is often overheated or large heat losses are noted. To meet these needs a new generation of heating pipes were used. They are hexagram-shaped pipes called “Walczak’s pipe”. Tubes of such shape have several times smaller volume in comparison with traditional heating pipes of the same outer diameter and higher stiffness. The preliminary assessment of the “Walczak’s pipe” installed in the greenhouse is highly positive. Compared with the traditional system it enables better heat management. In the first research stage, the thermal efficiency was defined in different ambient conditions at selected flow parameters and various water temperatures. With regard to the accepted flow values, it is notable that “Walczak’s pipe” has greater thermal efficiency per unit of power comparing with traditional tube. During the study, there was also a thermographic analysis of pipes’ surface performed and the heat flow distribution was determined. Analyzing the temperature distribution on the “Walczak’s pipe” remarkable are the areas with higher values ​​comparing with standard tube. It can be concluded that in the heating system with “Walczak’s pipe” energy transferred by radiation increases. This is particularly advantageous solution to use in greenhouses. It allows to obtain a higher leafs temperature with respect to the ambient temperature (vegetation heating. This parameter has a beneficial effect on the vegetative growth of cultivated plants.

Energy conserving dehumidification of greenhouses

NARCIS (Netherlands)

Zwart, de H.F.

2014-01-01

As greenhouses become better insulated and increasingly airtight, the humidity of the inside air rises easily and may become unfavourably high. Therefore, most greenhouses frequently open their vents to remove the moisture excess. When heated, opening the vents will increase the energy consumption.

Durum Wheat (Triticum Durum Desf. Lines Show Different Abilities to Form Masked Mycotoxins under Greenhouse Conditions

Directory of Open Access Journals (Sweden)

Martina Cirlini

2013-12-01

Full Text Available Deoxynivalenol (DON is the most prevalent trichothecene in Europe and its occurrence is associated with infections of Fusarium graminearum and F. culmorum, causal agents of Fusarium head blight (FHB on wheat. Resistance to FHB is a complex character and high variability occurs in the relationship between DON content and FHB incidence. DON conjugation to glucose (DON-3-glucoside, D3G is the primary plant mechanism for resistance towards DON accumulation. Although this mechanism has been already described in bread wheat and barley, no data are reported so far about durum wheat, a key cereal in the pasta production chain. To address this issue, the ability of durum wheat to detoxify and convert deoxynivalenol into D3G was studied under greenhouse controlled conditions. Four durum wheat varieties (Svevo, Claudio, Kofa and Neodur were assessed for DON-D3G conversion; Sumai 3, a bread wheat variety carrying a major QTL for FHB resistance (QFhs.ndsu-3B, was used as a positive control. Data reported hereby clearly demonstrate the ability of durum wheat to convert deoxynivalenol into its conjugated form, D3G.

Colonization with Arbuscular Mycorrhizal Fungi Promotes the Growth of Morus alba L. Seedlings under Greenhouse Conditions

Directory of Open Access Journals (Sweden)

Nan Lu

2015-03-01

Full Text Available Morus alba L. is an important tree species planted widely in China because of its economic value. In this report, we investigated the influence of two arbuscular mycorrhizal fungal (AMF species, Glomus mosseae and Glomus intraradices, alone and together, on the growth of M. alba L. seedlings under greenhouse conditions. The growth parameters and physiological performance of M. alba L. seedlings were evaluated 90 days after colonization with the fungi. The growth and physiological performance of M. alba L. seedlings were significantly affected by the AMF species. The mycorrhizal seedlings were taller, had longer roots, more leaves and a greater biomass than the non-mycorrhizae-treated seedlings. In addition, the AMF species-inoculated seedlings had increased root activity and a higher chlorophyll content compared to non-inoculated seedlings. Furthermore, AMF species colonization increased the phosphorus and nitrogen contents of the seedlings. In addition, simultaneous root colonization by the two AMF species did not improve the growth of M. alba L. seedlings compared with inoculation with either species alone. Based on these results, these AMF species may be applicable to mulberry seedling cultivation.

Heterogeneous Multi-Robot System for Mapping Environmental Variables of Greenhouses.

Science.gov (United States)

Roldán, Juan Jesús; Garcia-Aunon, Pablo; Garzón, Mario; de León, Jorge; Del Cerro, Jaime; Barrientos, Antonio

2016-07-01

The productivity of greenhouses highly depends on the environmental conditions of crops, such as temperature and humidity. The control and monitoring might need large sensor networks, and as a consequence, mobile sensory systems might be a more suitable solution. This paper describes the application of a heterogeneous robot team to monitor environmental variables of greenhouses. The multi-robot system includes both ground and aerial vehicles, looking to provide flexibility and improve performance. The multi-robot sensory system measures the temperature, humidity, luminosity and carbon dioxide concentration in the ground and at different heights. Nevertheless, these measurements can be complemented with other ones (e.g., the concentration of various gases or images of crops) without a considerable effort. Additionally, this work addresses some relevant challenges of multi-robot sensory systems, such as the mission planning and task allocation, the guidance, navigation and control of robots in greenhouses and the coordination among ground and aerial vehicles. This work has an eminently practical approach, and therefore, the system has been extensively tested both in simulations and field experiments.

Heterogeneous Multi-Robot System for Mapping Environmental Variables of Greenhouses

Directory of Open Access Journals (Sweden)

Juan Jesús Roldán

2016-07-01

Full Text Available The productivity of greenhouses highly depends on the environmental conditions of crops, such as temperature and humidity. The control and monitoring might need large sensor networks, and as a consequence, mobile sensory systems might be a more suitable solution. This paper describes the application of a heterogeneous robot team to monitor environmental variables of greenhouses. The multi-robot system includes both ground and aerial vehicles, looking to provide flexibility and improve performance. The multi-robot sensory system measures the temperature, humidity, luminosity and carbon dioxide concentration in the ground and at different heights. Nevertheless, these measurements can be complemented with other ones (e.g., the concentration of various gases or images of crops without a considerable effort. Additionally, this work addresses some relevant challenges of multi-robot sensory systems, such as the mission planning and task allocation, the guidance, navigation and control of robots in greenhouses and the coordination among ground and aerial vehicles. This work has an eminently practical approach, and therefore, the system has been extensively tested both in simulations and field experiments.

Nuclear energy and the greenhouse effect

International Nuclear Information System (INIS)

Weinberg, A.M.

1990-01-01

The extent and nature of the greenhouse effect are examined and placed in an environmental and historical context. The effect of energy policies on the greenhouse effect are discussed and the offending countries are identified. What energy policies would mitigate the greenhouse effect, and yet make good sense whether or not the effect proves to be real? Conservation is a desirable though not completely understood strategy. Conservation may not be a better bet in every instance than is increase in supply. If the greenhouse effect turns out to be real, nuclear energy can be one of the supply options that we turn to. If the greenhouse effect turns out to be false, and acceptable, economic nuclear option is surely better than one that does nothing but create strife and dissension. Let us remember that nuclear energy is the only large-scale non-fossil source other than hydropower that has been demonstrated to be practical. (author)

GREENHOUSE GASES AND MEANS OF PREVENTION

Directory of Open Access Journals (Sweden)

Dušica Stojanović

2013-09-01

Full Text Available The greenhouse effect can be defined as the consequence of increased heating of the Earth's surface, as well as the lower atmosphere by carbon dioxide, water vapor, and other trace amounts gases. It is well-known that human industrial activities have released large amounts of greenhouse gases in the atmosphere, about 900 billion tons of carbon dioxide, and it is estimated that up to 450 billion are still in the atmosphere. In comparison to greenhouse gases water vapor is one of the greatest contributors to the greenhouse effect on Earth. Many projects, as does the PURGE project, have tendences to build on the already conducted research and to quantify the positive and negative impacts on health and wellbeing of the population with greenhouse gas reduction strategies that are curently being implemented and should be increasingly applied in various sectors and urban areas, having offices in Europe, China and India.

Modeling of greenhouse with PCM energy storage

International Nuclear Information System (INIS)

Najjar, Atyah; Hasan, Afif

2008-01-01

Greenhouses provide a controlled environment that is suitable for plants growth and cultivation. In this paper the maximum temperature change inside the greenhouse is to be reduced by the use of energy storage in a phase change material PCM. A mathematical model is developed for the storage material and for the greenhouse. The coupled models are solved using numerical methods and Java code program. The effect of different parameters on the inside greenhouse temperature is investigated. The temperature swing between maximum and minimum values during 24 h can be reduced by 3-5 deg. C using the PCM storage. This can be improved further by enhancing the heat transfer between the PCM storage and the air inside the greenhouse

Modeling of greenhouse with PCM energy storage

Energy Technology Data Exchange (ETDEWEB)

Najjar, Atyah [Computation Science, Birzeit University, Birzeit (PS); Hasan, Afif [Mechanical Engineering Department, Birzeit University, Birzeit (PS)

2008-11-15

Greenhouses provide a controlled environment that is suitable for plants growth and cultivation. In this paper the maximum temperature change inside the greenhouse is to be reduced by the use of energy storage in a phase change material PCM. A mathematical model is developed for the storage material and for the greenhouse. The coupled models are solved using numerical methods and Java code program. The effect of different parameters on the inside greenhouse temperature is investigated. The temperature swing between maximum and minimum values during 24 h can be reduced by 3-5 C using the PCM storage. This can be improved further by enhancing the heat transfer between the PCM storage and the air inside the greenhouse. (author)

Emission and Sink of Greenhouse Gases in Soils of Moscow

Science.gov (United States)

Mozharova, N. V.; Kulachkova, S. A.; Lebed'-Sharlevich, Ya. I.

2018-03-01

The first inventory and zoning of the emission and sink of methane and carbon dioxide in the urban structure of greenhouse gases from soils and surface technogenic formations (STFs) (Technosols) on technogenic, recrementogenic, and natural sediments have been performed with consideration for the global warming potential under conditions of different formation rate of these gases, underflooding, and sealing. From gas geochemical criteria and anthropogenic pedogenesis features, the main sources of greenhouse gases, their intensity, and mass emission were revealed. The mass fractions of emissions from the sectors of waste and land use in the inventories of greenhouse gas emissions have been determined. New sources of gas emission have been revealed in the first sector, the emissions from which add tens of percent to the literature and state reports. In the second sector, emissions exceed the available data in 70 times. Estimation criteria based on the degree of manifestation and chemical composition of soil-geochemical anomalies and barrier capacities have been proposed. The sink of greenhouse gases from the atmosphere and the internal (latent) sink of methane in soils and STFs have been determined. Ecological functions of soils and STFs have been shown, and the share of latent methane sink has been calculated. The bacterial oxidation of methane in soils and STFs exceeds its emission to the atmosphere in almost hundred times.

Optimal Control Design for a Solar Greenhouse

NARCIS (Netherlands)

Ooteghem, van R.J.C.

2010-01-01

Abstract: An optimal climate control has been designed for a solar greenhouse to achieve optimal crop production with sustainable instead of fossil energy. The solar greenhouse extends a conventional greenhouse with an improved roof cover, ventilation with heat recovery, a heat pump, a heat

Greenhouse gas trading starts up

Science.gov (United States)

Showstack, Randy

While nations decide on whether to sign on to the Kyoto Protocol on climate change, some countries and private companies are moving forward with greenhouse gas emissions trading.A 19 March report, "The Emerging International Greenhouse Gas Market," by the Pew Center on Global Climate Change, reports that about 65 greenhouse gas emissions trades for quantities above 1,000 metric tons of carbon dioxideequivalent already have occurred worldwide since 1996. Many of these trades have taken place under a voluntary, ad hoc framework, though the United Kingdom and Denmark have established their own domestic emissions trading programs.

Sweet pepper greenhouse production under different depletion levels in substrate humidity

Directory of Open Access Journals (Sweden)

Gustavo Quesada Roldán

2015-06-01

Full Text Available The effect of 3 substrate humidity levels on the growth and yield of 2 sweet pepper hybrids, established under greenhouse conditions, was evaluated. The experiment was held in the industrial greenhouse of the Fabio Baudrit Moreno Experimental Research Station, in La Garita (Alajuela, and the materials evaluated were the hybrids Villaplants Americano (square yellow fruit, bell type and FBM-9 (triangular red fruit type, both national origin genotypes. The first treatment was to supply water at container capacity (CC to the plant, while the second and third ones were reducing 15 and 30%, respectively, of the plant original water supply. It was demonstrated that there is no effect due to the amount of water supply on the plant´s growth, although it was observed that hydric- stressed plants were the first to begin the flowering and fruiting phase. In both hybrids, a reduction in the amount of first and second one amount quality fruit and an increasing of fruit rejected as the watering was limited. Blossom-end rot was the main rejection cause due to the water loss, associated with low calcium availability. The highest commercial yield was obtained with the Villaplants Americano hibryd (31,8 ton.ha-1, although without statistical difference between substrates at CC and CC–15%, despite a fruit quality reduction with the later treatment. The same was observed with the FBM-9 hybrid. With the CC–30% treatment, both commercial yield and fruit quality were affected, in both hybrids.

Improving radiation use efficiency in greenhouse production systems

OpenAIRE

Li, Tao

2015-01-01

SUMMARY A large increase in agricultural production is needed to feed the increasing world population with their increasing demand per capita. However, growing competition for arable land, water, energy, and the degradation of the environment impose challenges to improve crop production. Hence agricultural production efficiency needs to increase. Greenhouses provide the possibility to create optimal growth conditions for crops, thereby improving production and product quality. Light is the dr...

Optimal control design for a solar greenhouse

NARCIS (Netherlands)

Ooteghem, van R.J.C.

2007-01-01

The research of this thesis was part of a larger project aiming at the design of a greenhouse and an associated climate control that achieves optimal crop production with sustainable instead of fossil energy. This so called solar greenhouse design extends a conventional greenhouse with an improved

Has your greenhouse gone virtual?

Science.gov (United States)

Virtual Grower is a free decision-support software program available from USDA-ARS that allows growers to build a virtual greenhouse. It was initially designed to help greenhouse growers estimate heating costs and conduct simple simulations to figure out where heat savings could be achieved. Featu...

Greenhouse gas strategy

International Nuclear Information System (INIS)

2001-03-01

Because the overall effects of climate change will likely be more pronounced in the North than in other parts of the country, the Government of the Northwest Territories considers it imperative to support global and local actions to reduce greenhouse gas emissions. Government support is manifested through a coordinating role played by senior government representatives in the development of the NWT Greenhouse Gas Strategy, and by participation on a multi-party working committee to identify and coordinate northern actions and to contribute a northern perspective to Canada's National Climate Change Implementation Strategy. This document outlines the NWT Government's goals and objectives regarding greenhouse gas emission reduction actions. These will include efforts to enhance awareness and understanding; demonstrate leadership by putting the Government's own house in order; encouraging action across sectors; promote technology development and innovation; invest in knowledge and building the foundation for informed future decisions. The strategy also outlines the challenges peculiar to the NWT, such as the high per person carbon dioxide emissions compared to the national average (30 tonnes per person per year as opposed to the national average of 21 tonnes per person per year) and the increasing economic activity in the Territories, most of which are resource-based and therefore energy-intensive. Appendices which form part of the greenhouse gas strategy document, provide details of the potential climate change impact in the NWT, a detailed explanation of the proposed measures, an emission forecast to 2004 from industrial processes, fuel combustion and incineration, and a statement of the official position of the Government of the NWT on climate change

Simulation of Greenhouse Climate Monitoring and Control with Wireless Sensor Network and Event-Based Control

Science.gov (United States)

Pawlowski, Andrzej; Guzman, Jose Luis; Rodríguez, Francisco; Berenguel, Manuel; Sánchez, José; Dormido, Sebastián

2009-01-01

Monitoring and control of the greenhouse environment play a decisive role in greenhouse production processes. Assurance of optimal climate conditions has a direct influence on crop growth performance, but it usually increases the required equipment cost. Traditionally, greenhouse installations have required a great effort to connect and distribute all the sensors and data acquisition systems. These installations need many data and power wires to be distributed along the greenhouses, making the system complex and expensive. For this reason, and others such as unavailability of distributed actuators, only individual sensors are usually located in a fixed point that is selected as representative of the overall greenhouse dynamics. On the other hand, the actuation system in greenhouses is usually composed by mechanical devices controlled by relays, being desirable to reduce the number of commutations of the control signals from security and economical point of views. Therefore, and in order to face these drawbacks, this paper describes how the greenhouse climate control can be represented as an event-based system in combination with wireless sensor networks, where low-frequency dynamics variables have to be controlled and control actions are mainly calculated against events produced by external disturbances. The proposed control system allows saving costs related with wear minimization and prolonging the actuator life, but keeping promising performance results. Analysis and conclusions are given by means of simulation results. PMID:22389597

Simulation of Greenhouse Climate Monitoring and Control with Wireless Sensor Network and Event-Based Control

Directory of Open Access Journals (Sweden)

Andrzej Pawlowski

2009-01-01

Full Text Available Monitoring and control of the greenhouse environment play a decisive role in greenhouse production processes. Assurance of optimal climate conditions has a direct influence on crop growth performance, but it usually increases the required equipment cost. Traditionally, greenhouse installations have required a great effort to connect and distribute all the sensors and data acquisition systems. These installations need many data and power wires to be distributed along the greenhouses, making the system complex and expensive. For this reason, and others such as unavailability of distributed actuators, only individual sensors are usually located in a fixed point that is selected as representative of the overall greenhouse dynamics. On the other hand, the actuation system in greenhouses is usually composed by mechanical devices controlled by relays, being desirable to reduce the number of commutations of the control signals from security and economical point of views. Therefore, and in order to face these drawbacks, this paper describes how the greenhouse climate control can be represented as an event-based system in combination with wireless sensor networks, where low-frequency dynamics variables have to be controlled and control actions are mainly calculated against events produced by external disturbances. The proposed control system allows saving costs related with wear minimization and prolonging the actuator life, but keeping promising performance results. Analysis and conclusions are given by means of simulation results.

Dissipation and enantioselective degradation of plant growth retardants paclobutrazol and uniconazole in open field, greenhouse, and laboratory soils.

Science.gov (United States)

Wu, Chengwang; Sun, Jianqiang; Zhang, Anping; Liu, Weiping

2013-01-15

Greenhouses are increasingly important in human food supply. Pesticides used in greenhouses play important roles in horticulture; however, little is known about their behavior in greenhouse environments. This work investigates the dissipation and enantioselctive degradation of plant growth retardants including paclobutrazol and uniconazole in soils under three conditions (i.e., open field, greenhouse, and laboratory). The dissipation and enantioselective degradation of paclobutrazol and uniconazole in greenhouse were different from those in open field; they were more persistent in greenhouse than in open field soil. Leaching produced by rainfall is responsible for the difference in dissipation. Thus, local environmental impacts may occur more easily inside greenhouses, while groundwater may be more contaminated in open field. Spike concentrations of 5, 10, and 20 times the concentrations of native residues were tested for the enantioselective dissipation of the two pesticides; the most potent enantioselective degradation of paclobutrazol and uniconazole occurred at the 10 times that of the native residues in the greenhouse environments and at 20 times native residues in open field environments. The higher soil activity in greenhouses than in open fields was thought to be responsible for such a difference. The environmental risk and regulation of paclobutrazol and uniconazole should be considered at the enantiomeric level.

Irrigation and nitrogen level affect lettuce yield in greenhouse ...

African Journals Online (AJOL)

This study was conducted to investigate the effect of different irrigation and nitrogen levels on lettuce yield characteristics in greenhouse condition from December 2006 to March 2007. Irrigation levels of 100% of total class A pan (S1), 80% of total class A pan (S2), 60% of total class A pan (S3) and nitrogen levels of 0 kg ...

Design of experimental system for supercritical CO2 fracturing under confining pressure conditions

Science.gov (United States)

Wang, H.; Lu, Q.; Li, X.; Yang, B.; Zheng, Y.; Shi, L.; Shi, X.

2018-03-01

Supercritical CO2 has the characteristics of low viscosity, high diffusion and zero surface tension, and it is considered as a new fluid for non-polluting and non-aqueous fracturing which can be used for shale gas development. Fracturing refers to a method of utilizing the high-pressure fluid to generate fractures in the rock formation so as to improve the oil and gas flow conditions and increase the oil and gas production. In this article, a new type of experimental system for supercritical CO2 fracturing under confining pressure conditions is designed, which is based on characteristics of supercritical CO2, shale reservoir and down-hole environment. The experimental system consists of three sub-systems, including supercritical CO2 generation system, supercritical CO2 fracturing system and data analysis system. It can be used to simulate supercritical CO2 fracturing under geo-stress conditions, thus to study the rock initiation pressure, the formation of the rock fractures, fractured surface morphology and so on. The experimental system has successfully carried out a series of supercritical CO2 fracturing experiments. The experimental results confirm the feasibility of the experimental system and the high efficiency of supercritical CO2 in fracturing tight rocks.

[Is there a connection between biodiversity and the greenhouse effect].

Science.gov (United States)

Rozanov, S I

1998-01-01

It was discussed the role of biodiversity in ecosystems capacity to control CO2 in atmosphere as the main reason not only of "greenhouse effect" but "greenhouse catastrophe". The necessity to perfect the preventive measures has been defined by time factor. This time may be so little for completing the evolution theory and models of biosphere management. The temps of contemporaneous species extinction exceed two orders as minimum ones how it has been known from planet history. It doesn't permit to discharge that evolutional process will be successful to create organisms which have been capable to stabilize biosphere in conditions of its changing status. It's possible that such change may be provocated with the crisis in civilization-biosphere interrelations.

An assessment of the torrefaction of North American pine and life cycle greenhouse gas emissions

International Nuclear Information System (INIS)

McNamee, P.; Adams, P.W.R.; McManus, M.C.; Dooley, B.; Darvell, L.I.; Williams, A.; Jones, J.M.

2016-01-01

Highlights: • Torrefaction of North American pine improves fuel properties. • Comparative LCA is presented of wood pellet and torrefied wood pellet supply. • Torrefied pellets offer energy and greenhouse gas savings but increase land use. • Torgas use is crucial for emission savings to offset fossil fuel use as utility fuel. • Shipping contributes largest emissions and long distance favours torrefied pellets. - Abstract: Bioenergy is increasingly being used to meet EU objectives for renewable energy generation and reducing greenhouse gas (GHG) emissions. Problems with using biomass however include high moisture contents, lower calorific value and poor grindability when compared to fossil fuels. Torrefaction is a pre-treatment process that aims to address these issues. In this paper four torrefaction treatments of pine were performed and a mass–energy balance calculated. Using experimental data, a pellet production supply chain incorporating torrefaction was modelled and compared to an existing wood pellet system to determine life-cycle GHG emissions. Two utility fuels, wood chips and natural gas, were considered to provide process heat in addition to volatile gases released during torrefaction (torgas). Experimental results show that torrefaction reduces the moisture content and increases the calorific value of the fuels. Increasing torrefaction temperature and residence time results in lower mass and energy yields. GHG emissions reduce with increasing torrefaction severity. Emissions from drying & torrefaction and shipping are the highest GHG contributors to the supply chain. All 4 torrefaction conditions assessed outperformed traditional wood pellet supply chain emissions but more land is required which increases with temperature and residence time. Sensitivity analysis results show that emissions increase significantly where natural gas is used for utility fuel and no torgas is utilised.

Simulation of the plant uptake of organophosphates and other emerging pollutants for greenhouse experiments and field conditions

DEFF Research Database (Denmark)

Trapp, Stefan; Eggen, Trine

2013-01-01

The uptake of the organophosphates tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), tributyl phosphate (TBP), the insect repellant N,N-diethyl toluamide (DEET), and the plasticizer n-butyl benzenesulfonamide (NBBS) into plants was studied in greenhouse experiments...

Voluntary reporting of greenhouse gases, 1995

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-07-01

The Voluntary Reporting Program for greenhouse gases is part of an attempt by the U.S. Government to develop innovative, low-cost, and nonregulatory approaches to limit emissions of greenhouse gases. It is one element in an array of such programs introduced in recent years as part of the effort being made by the United States to comply with its national commitment to stabilize emissions of greenhouse gases under the Framework Convention on Climate Change. The Voluntary Reporting Program, developed pursuant to Section 1605(b) of the Energy Policy Act of 1992, permits corporations, government agencies, households, and voluntary organizations to report to the Energy Information Administration (EIA) on actions taken that have reduced or avoided emissions of greenhouse gases.

Greenhouse gas mitigation options for Washington State

Energy Technology Data Exchange (ETDEWEB)

Garcia, N.

1996-04-01

President Clinton, in 1993, established a goal for the United States to return emissions of greenhouse gases to 1990 levels by the year 2000. One effort established to help meet this goal was a three part Environmental Protection Agency state grant program. Washington State completed part one of this program with the release of the 1990 greenhouse gas emissions inventory and 2010 projected inventory. This document completes part two by detailing alternative greenhouse gas mitigation options. In part three of the program EPA, working in partnership with the States, may help fund innovative greenhouse gas reduction strategies. The greenhouse gas control options analyzed in this report have a wide range of greenhouse gas reductions, costs, and implementation requirements. In order to select and implement a prudent mix of control strategies, policy makers need to have some notion of the potential change in climate, the consequences of that change and the uncertainties contained therein. By understanding the risks of climate change, policy makers can better balance the use of scarce public resources for concerns that are immediate and present against those that affect future generations. Therefore, prior to analyzing alternative greenhouse gas control measures, this report briefly describes the phenomenon and uncertainties of global climate change, and then projects the likely consequences for Washington state.

Greenhouse governance: An Australian iconoclast`s view

Energy Technology Data Exchange (ETDEWEB)

O`Brien, B.J. [Brian J O`Brien Associates Pty Ltd, Floreat Park, WA (Australia)

1996-10-01

The `No Regrets` policy was an imported stop-gap measure taken over five years ago when greenhouse fears were large and knowledge small. This paper suggests that this policy by 1995 is actually a `Three Regrets Policy` for Australia. Regret 1 is that El Nino effects which greatly affect Australia are given lower priority than greenhouse. Regret 2 is the deteriorating image and role of Science and Engineering in Australian society. Regret 3 is the growing domination of the energy debate by greenhouse. It is suggested that greenhouse fears should be put into an updated Australian perspective. The issues of sea level rise, and increasing temperatures are updated. It is believed that recognition of the importance of natural climate variation is increasing, this is not yet being used to put greenhouse into popular perspective. The paper concludes with five suggested actions to turn the `Three Regrets for Australia` into one that truly is `no regrets` for Australia. Putting greenhouse in perspective means a vigorous program of investigating and gradually understanding the whole suite of influences on the climate, natural as well as greenhouse. It includes making a competitive advantage out of the climate variabilities in Australia, from more accurate seasonal forecasts. (author). 3 tabs., 4 figs., refs.

Computational Fluid Dynamics Modeling to Improve Natural Flow Rate and Sweet Pepper Productivity in Greenhouse

Directory of Open Access Journals (Sweden)

W. Limtrakarn

2012-01-01

Full Text Available Natural flow rate and sweet peppers productivity in tropical greenhouse are improved by CFD simulation is the main objective of this research work. Most of the greenhouse types today are in the arch shape. To develop an improved greenhouse structure for the region, the arch type was built and used as the control model. Mae Sar Mai agriculture research station under the royal project foundation was selected as the field test site. Temperature sensors with data logger were installed to monitor variation of temperature inside the greenhouse. The measured temperature data were used as the boundary conditions for the CFD analysis. A new greenhouse model with two-step roof shape was designed and the air flow behavior was simulated by using CFD. Regarding CFD results the air flow rate of the new model is about 39% higher than that of old model. The maximum temperature of the new model is lower than that of the old one. The sweet paper growths in both greenhouse models were measured and compared. Results show that the new model obtains 4°C lower maximum temperature in day time, 97% in number and 90% in weight higher the first grade pepper productivity than the old one.

Building and using the solar greenhouse

Energy Technology Data Exchange (ETDEWEB)

None

1983-01-01

Thorough directions are given for planning, constructing and using a solar greenhouse attached to a house. Included is a method of calculating the savings accruing from the use of the greenhouse. (LEW)

MEMS climate sensor for crops in greenhouses

International Nuclear Information System (INIS)

Birkelund, K; Jensen, Kim Degn; Højlund-Nielsen, Emil; Nagstrup, Johan; Lei, Anders; Petersen, Søren Dahl; Thomsen, Erik V; Andreassen, Andrea U

2010-01-01

We have developed and fabricated a multi-sensor chip for greenhouse applications and demonstrated the functionality under controlled conditions. The sensor consists of a humidity sensor, temperature sensor and three photodiodes sensitive to blue, red and white light, respectively. The humidity sensor responds linearly with humidity with a full scale change of 5.6 pF. The best performing design measures a relative change of 48%. The temperature sensor responds linearly with temperature with a temperature coefficient of resistance of 3.95 × 10 −3 K −1 and a sensitivity of 26.5 Ω °C −1 . The three photodiodes have been characterized and show an almost ideal diode behavior with an ideality factor of 1.27 and a series resistance of 14.9 Ω. The diodes are sensitive to blue, red and white light with the measured quantum efficiencies of 69%, 81% and 68%, respectively. The temperature and humidity sensors have further been tested on plants in a greenhouse, demonstrating that individual plant behavior can be monitored.

Technological substitution options for controlling greenhouse gas emissions

International Nuclear Information System (INIS)

Barbier, E.B.; Burgess, J.C.; Pearce, D.W.

1991-01-01

This chapter is concerned with technological options for greenhouse gas substitution. The authors interpret the term substitution to exclude energy conservation/efficiency measures, investments in afforestation (sinks), and greenhouse gas removal or abatement technologies. Their working definition of greenhouse gas substitution includes (1) replacement technologies, for example, substituting a greenhouse gas technology with a nongreenhouse gas technology; and (2) reduction technologies, for example, substituting a greenhouse gas technology with an alternative technology that reduces greenhouse gas emissions. Essentially, replacement technologies involve 100 percent reduction in CO 2 ; reduction technologies involve a partial reduction in CO 2 . Of the man-made sources of greenhouse gases, energy is the most important and is expected to contribute to at least half of the global warming effect in the near future. The majority of this impact is from fossil fuel combustion as a source of carbon dioxide (CO 2 ), although fossil fuels also contribute significantly to methane (CH 4 ), to nitrous oxide (N 2 O), and to low-level ozone (O 3 ) through production of various nitrogen gases (NO x ) and carbon monoxide (CO). This study analyzes the available greenhouse gas substitutions and their costs. The authors concentrate particularly on substitutions for fossil-fuel combustion and CFC production and consumption. They conclude by summarizing the potential for greenhouse gas substitution, the cost-effectiveness of the various options and the design of incentives for substitution

Experimental and numerical study of an evaporatively-cooled condenser of air-conditioning systems

International Nuclear Information System (INIS)

Islam, M.R.; Jahangeer, K.A.; Chua, K.J.

2015-01-01

The performance of an air-conditioning unit with evaporately-cooled condenser coil is studied experimentally and numerically. An experimental setup is fabricated by retrofitting a commercially available air-conditioning unit and installing comprehensive measuring sensors and controllers. Experimental result shows that the COP (Coefficient of Performance) of the evaporately-cooled air-conditioning unit increases by about 28% compared to the conventional air cooled air-conditioning unit. To analyze the heat and mass transfer processes involved in the evaporately-cooled condenser, a detailed theoretical model has been developed based on the fluid flow characteristics of the falling film and the thermodynamic aspect of the evaporation process. Simulated results agree well with experimental data. The numerical model provides new insights into the intrinsic links between operating variables and heat transfer characteristics of water film in evaluating the performance of evaporatively-cooled condenser system. Two heat transfer coefficients, namely, wall to bulk and bulk to interface are introduced and computed from the simulation results under different operating conditions. Finally, the overall heat transfer coefficient for the water film is computed and presented as a function of dimensionless variables which can conveniently be employed by engineers to design and analyze high performance evaporatively-cooled heat exchangers. - Highlights: • Performance of evaporatively-cooled condenser is investigated. • Local convective heat transfer coefficients of water film are determined. • Thermal resistance of water film is negligible. • Heat transfer with evaporated vapor plays significant role on performance. • Better condenser performance translates to an improvement in COP

Comparing effects of low levels of herbicides on greenhouse- and field-grown potatoes (Solanum tuberosum L.), soybeans (Glycine max L.), and peas (Pisum sativum L.).

Science.gov (United States)

Pfleeger, Thomas; Olszyk, David; Lee, E Henry; Plocher, Milton

2011-02-01

Although laboratory toxicology tests are generally easy to perform, cost effective, and readily interpreted, they have been questioned for their environmental relevance. In contrast, field tests are considered realistic while producing results that are difficult to interpret and expensive to obtain. Toxicology tests were conducted on potatoes, peas, and soybeans grown in a native soil in pots in the greenhouse and were compared to plants grown outside under natural environmental conditions to determine toxicological differences between environments, whether different plant developmental stages were more sensitive to herbicides, and whether these species were good candidates for plant reproductive tests. The reproductive and vegetative endpoints of the greenhouse plants and field-grown plants were also compared. The herbicides bromoxynil, glyphosate, MCPA ([4-chloro-2-methylphenoxy] acetic acid), and sulfometuron-methyl were applied at below field application rates to potato plants at two developmental stages. Peas and soybeans were exposed to sulfometuron-methyl at similar rates at three developmental stages. The effective herbicide concentrations producing a 25% reduction in a given measure differed between experimental conditions but were generally within a single order of magnitude within a species, even though there were differences in plant morphology. This study demonstrated that potatoes, peas, and soybeans grown in pots in a greenhouse produce phytotoxicity results similar to those grown outside in pots; that reproductive endpoints in many cases were more sensitive than vegetative ones; and that potato and pea plants are reasonable candidates for asexual and sexual reproductive phytotoxicity tests, respectively. Plants grown in pots in a greenhouse and outside varied little in toxicity. However, extrapolating those toxicity results to native plant communities in the field is basically unknown and in need of research. © 2010 SETAC.

The Greenhouse Effect and Built Environment Education.

Science.gov (United States)

Greenall Gough, Annette; Gough, Noel

The greenhouse effect has always existed. Without the greenhouse effect, Earth could well have the oven-like environment of Venus or the deep-freeze environment of Mars. There is some debate about how much the Earth's surface temperature will rise given a certain amount of increase in the amount of greenhouse gases such as carbon dioxide, nitrous…

Nuclear power and the greenhouse effect

International Nuclear Information System (INIS)

Donaldson, D; Tolland, H.; Grimston, M.

1990-01-01

The greenhouse effect is first explained. The evidence is shown in global warming and changing weather patterns which are generally believed to be due to the emission of greenhouse gases, including carbon dioxide. Serious consequences are predicted if emission of the greenhouse gases is not reduced. Sources of these gases are identified - agriculture, carbon fluorocarbons, coal-fired power stations, vehicle exhausts. The need is to use energy more efficiently but such measures as combined heat and power stations, more fuel efficient cars and better thermal insulation in homes is advocated. The expansion of renewable energy sources such as wind and water power is also suggested. Nuclear power is promoted as it reduces the carbon dioxide emissions and in both the short and long-term will reduce the emission of greenhouse gases. (author)

Uso adequado de casa-de-vegetação e de telados na experimentação agrícola Appropriate use of greenhouse in the agricultural experimentation

Directory of Open Access Journals (Sweden)

Napoleão E. de M. Beltrão

2002-12-01

Full Text Available Neste trabalho, objetivou-se aglutinar elementos para o uso mais adequado de casas-de-vegetação e telados, com a finalidade de experimentação agrícola. São discutidos os fatores água, temperatura do ar e irradiância solar no interior de coberturas artificiais, bem como o manejo do ambiente em termos de tamanho de vasos, seu posicionamento nas casas-de-vegetação e o uso da água de irrigação. Deve-se evitar telas de cor verde (reflete o verde e absorve o vermelho, usado na fotossíntese e se deve ter os vasos sempre da mesma cor e tamanho.This paper reviews the main factors affecting the use of greenhouses in agricultural experimentation. The effects of water quality, air temperature and solar irradiance are discussed along with size, placement and color of pots/recipients and use of water in irrigation. Green screen should be avoided in greenhouses as they reflect the green light while absorbing the photosynthetically active red light. All the pots/recipients must be of the same color and size.

Potential for large-scale solar collector system to offset carbon-based heating in the Ontario greenhouse sector

Science.gov (United States)

Semple, Lucas M.; Carriveau, Rupp; Ting, David S.-K.

2018-04-01

In the Ontario greenhouse sector the misalignment of available solar radiation during the summer months and large heating demand during the winter months makes solar thermal collector systems an unviable option without some form of seasonal energy storage. Information obtained from Ontario greenhouse operators has shown that over 20% of annual natural gas usage occurs during the summer months for greenhouse pre-heating prior to sunrise. A transient model of the greenhouse microclimate and indoor conditioning systems is carried out using TRNSYS software and validated with actual natural gas usage data. A large-scale solar thermal collector system is then incorporated and found to reduce the annual heating energy demand by approximately 35%. The inclusion of the collector system correlates to a reduction of about 120 tonnes of CO2 equivalent emissions per acre of greenhouse per year. System payback period is discussed considering the benefits of a future Ontario carbon tax.

Steps toward a cooler greenhouse

International Nuclear Information System (INIS)

Kerr, R.A.

1991-01-01

In April a committee of the National Academies of Science and Engineering and the Institute of Medicine urged the Bush Administration and Congress to begin cutting emissions of greenhouse gases immediately. The risk of delay is great, and the cost of insurance against disastrous climate warming is cheap. Now the committee's panel on mitigation has issued a 500-page report describing just how cheap that hedge against a climate calamity could be. The panel found that it would not be unreasonable to expect that a 25% reduction in US greenhouse gas emissions might be achieved at a cost of less than $10 per ton of carbon dioxide or its equivalent in other greenhouse gases. In more familiar terms, that considerable reduction in greenhouse emissions would cost about $4.75 for each barrel of oil burned or $0.11 per gallon of gasoline. The most cost-effective measures for reducing emissions, are increasing the energy efficiency of residential and commercial buildings and activities, vehicles, and industrial processes that use electricity

The coal industry and its greenhouse challenge

International Nuclear Information System (INIS)

Armstrong, A.

1998-01-01

The Australian coal industry is actively involved in greenhouse gas emission management and abatement issues. An Australian Coal Association (ACA) position paper on greenhouse in November 1989, recommended a number of strategies to minimise the greenhouse effect, including the enhancement of energy utilisation efficiency, improved energy conversion efficiency at coal-fired power stations, expanded use of solar heating, and improved recycling. All of the strategies have been implemented to various degrees. The management and abatement of greenhouse gas emissions within the coal industry has been approached from an individual operational level, and a 'higher' industry level

Sourcebook on the greenhouse effect

International Nuclear Information System (INIS)

Ellis, E.; Devine, J.

1990-01-01

The Greenhouse Effect Sourcebook contains information for anyone interested in the environment and the present changes which are taking place. It can be used to trace organisations, technical literature or reports. Much of the information relates to the environment in general. The sourcebook contains:- A list of Greenhouse Effect Information useful sources of information under a variety of headings:-Abstracts and indexes, books, conferences, directories, journals, official publications, online databases, (produces and hosts) and organisations, -The Greenhouse Effect References contains over 250 abstracts and details of recently published material, on a variety of environmental subjects from acid rain and aerosols to weather forecasting and wildlife. There is an author index for the references and a keyword index. (author)

Effect of Elevated CO2 in Different Fertilizer Conditions on Physiological Traits in Lemon Balm (Melissa officinalis at Greenhouse

Directory of Open Access Journals (Sweden)

M Shoor

2012-07-01

Full Text Available Increasing atmospheric CO2 concentrations and nutrients supply are generally expected to enhance photosynthesis and growth of crops as a result considerably increase yields. The present study aims to investigate effects of elevated CO2 and different fertilizer conditions on physiological traits in Lemon balm. A factorial experiment was conducted based on completely randomized design with three replications and nine treatments at the greenhouse in 2010. The experiment factors were included three CO2 concentrations (380, 700 and 1050 ppm and three kinds of conditions fertilizer (no fertilizer, manure fertilizer and nitrogen fertilizer. The results indicated that increasing of CO2 from 380 to 1050 ppm led to improve in leaf area, plant height, relative growth ratio, total dry matter and final yield of individual plant. The highest and the lowest amount of measured traits related to with and without nitrogen fertilizer, respectively. Impact of elevated CO2 in conjunction with nitrogen and manure fertilizers increased. These effects were more on total dry matter and final yield than other growth indices. Therefore, it can be concluded that, whereas increase of temperature caused by rising CO2 is not considered or there is not any limitation for resources, CO2 enrichment will be improved lemon balm production.

Per capita emissions of greenhouse gases and international trade

International Nuclear Information System (INIS)

Karman, D.; Baptiste, S.

1994-01-01

The role played by international trade in Canada's emissions of greenhouse gases is investigated. Data used in the study include Environment Canada greenhouse gas emission estimates for 1990, a Statistics Canada input-output model linking greenhouse gas emissions to economic activity in different sectors, and monetary statistics on imports and exports. Subject to some simplifying assumptions, it is estimated that nearly 20% of Canada's greenhouse gas emissions can be attributed to the production of commodities destined for export to other countries. If the same greenhouse gas emission intensities are assumed for Canada's imports, the greenhouse gas emissions due to Canada's net trade is nearly 7% of the 660 megatonnes of CO 2 equivalent emissions for 1990. Commodities from natural resource exploitation head the list of greenhouse gas emissions attributed to international trade, as expected from their large export volumes and large greenhouse gas emission intensities. 4 refs., 1 fig

Foxes, hedgehogs, and greenhouse governance: Knowledge, uncertainty, and international policy-making in a warming World

International Nuclear Information System (INIS)

Michel, David

2009-01-01

Global environmental challenges like greenhouse warming are characterized by profound uncertainties about the workings of complex systems, high stakes as to the costs and benefits of various possible actions, and important differences concerning the values that should shape public choices, confounding ready resolution by conventional decision-making procedures. So-called adaptive or reflexive governance strategies provide policy-makers an alternative framework for tackling the greenhouse problem. Adaptive governance employs deliberate experimentation and continuous learning-by-doing to test and adjust ongoing policy responses. Yet pursuing such approaches poses particular challenges to global climate cooperation. In an increasingly interdependent world, coordinating multiple parties experimentally adopting different climate measures could prove contentious. Unequivocal policy lessons may be difficult to draw and apply. Timely collective revisions to ongoing policies may prove more difficult still to define and agree. Advocates must engage these issues directly and develop means of addressing them if adaptive governance approaches are to allow policy-makers to formulate better strategies for combating climate change. (author)

Development of concepts for a zero-fossil-energy greenhouse

NARCIS (Netherlands)

Ooster, A. van 't; Henten, E.J. van; Janssen, E.G.O.N.; Bot, G.P.A.; Dekker, E.

2008-01-01

Dutch government and greenhouse horticultural practice aim for strongly reduced fossil energy use and of environmental loads in 2010 and energy neutral greenhouses in 2020. This research aims to design a greenhouse concept with minimal use of fossil energy and independent of nearby greenhouses. The

Greenhouse Gas reduction for scenarios of power sources development of the Republic of Moldova

Directory of Open Access Journals (Sweden)

Comendant I.

2010-04-01

Full Text Available For the new power market conditions, Moldova power sources development options up to 2033 are evaluated, and for the six scenarios selected the greenhouse gas reduction impact is determined.

The sterile insect technique in the integrated pest management of whitefly species in greenhouses

International Nuclear Information System (INIS)

Calvitti, M.; Remotti, P.C.; Cirio, U.

2000-01-01

Insect pests commonly known as whiteflies are Hemiptera belonging to the family of Aleyrodidae Trialeurodes vaporariorum Westwood (greenhouse whitefly) and the B-biotype of Bemisia tabaci Gennadius (=Bemisia argentifolii Bellows and Perring) are pests whose economic importance is constantly increasing within the European agriculture. The B-biotype of B. tabaci, in particular, has become more problematic by causing damage over a wide range, from the temperate climates of Californian squash fields to European greenhouses and field crops. In the absence of valid alternatives, many growers have resorted to intensive application of insecticides to control these pests, creating a severe environmental and health hazard. Several new environmentally safe technologies are currently available and have opened up new opportunities in the integrated pest management (IPM) of whiteflies under greenhouse conditions. In particular, biological or biologically-based control means, including a number of fungi, insects, and compounds have been recently developed. However, the limitation of whitefly population outbreaks in greenhouses is a problem that needs to be solved. The idea to extend the use of sterile insect technique (SIT) to a confined environment against whitefly species is novel, and especially when we consider that the target species undergo arrhenotoky (unfertilised females generate only male progenies). The possibility to join this approach to the Integrated Pest Management (IPM) of the whitefly species in the greenhouse may open new perspectives in the safe application of nuclear technology for pest control. The present work reviews recent advances in research and practice related to the development of SIT for the control of whiteflies in greenhouses. Explanations on whitefly radiation biology, with data on Bemisia spp. radio-sterilisation, methods for whitefly mass rearing and collection, and the definition of a complete SIT procedure tested against the greenhouse

Using waste oil to heat a greenhouse

Science.gov (United States)

Marla Schwartz

2009-01-01

During the winter of 1990, Northwoods Nursery (Elk River, ID) purchased a wood-burning system to heat the current greenhouses. This system burned slabs of wood to heat water that was then pumped into the greenhouses. The winter of 1990 was extremely harsh, requiring non-stop operation of the heating system. In order to keep seedlings in the greenhouse from freezing,...

The solar greenhouse: a survey of energy saving methods

NARCIS (Netherlands)

Saye, A.; Loon, van W.K.P.; Bot, G.P.A.; Zwart, de H.F.

2000-01-01

The solar greenhouse project is aimed at the development of a greenhouse concept for the Netherlands with zero-fossil energy consumption. The solar greenhouse is formulated as a combination of a low energy demand greenhouse, an energy recovery installation and an energy storage facility. In this

Greenhouse effect, energy conservation; Effet de serre, economie d`energie

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

This symposium is composed of 12 communications grouped in three sessions which titles and themes are: influence of the greenhouse gas emission reduction policy on refrigerating and air conditioning engineering; characteristics and performances of refrigerants and working fluids, circuit architectures, two-phase fluids, single-tube systems and district cooling systems; principles and characteristics of thermo-pumps for heating, refrigerating and air conditioning applications, more especially in residential and small commercial buildings (air condensation thermo-pumps, ammonia thermo-pumps, ground source thermo-pumps), quality assurance

Scientific perspectives on greenhouse problem. Part 2

International Nuclear Information System (INIS)

Jastrow, R.; Nierenberg, W.; Seitz, F.

1992-01-01

The spectre of major climate change caused by the greenhouse effect has generated intensive research, heated scientific debate and a concerted international effort to draft agreements for the reduction of greenhouse gas emissions. This report of Scientific Perspectives on the greenhouse problem explains the technical issues in the debate in language readily understandable to the non-specialist. The inherent complexities of attempts to simulate the earth's climate are explained, particularly with regard to the effects of clouds and the circulation of the oceans, which together represent the largest factors of uncertainty in current global warming forecasts. Results of the search for the 'greenhouse signal' in existing climate records aredescribed in chapter 3 (part two). Chapter 5 (part two) develops a projection of 21st-century warming based on relatively firm evidence of the earth's actual response to known increases in greenhouse gas emissions during the last 100 years

Reservoir Greenhouse Gas Emissions at Russian HPP

Energy Technology Data Exchange (ETDEWEB)

Fedorov, M. P.; Elistratov, V. V.; Maslikov, V. I.; Sidorenko, G. I.; Chusov, A. N.; Atrashenok, V. P.; Molodtsov, D. V. [St. Petersburg State Polytechnic University (Russian Federation); Savvichev, A. S. [Russian Academy of Sciences, S. N. Vinogradskii Institute of Microbiology (Russian Federation); Zinchenko, A. V. [A. I. Voeikov Main Geophysical Observatory (Russian Federation)

2015-05-15

Studies of greenhouse-gas emissions from the surfaces of the world’s reservoirs, which has demonstrated ambiguity of assessments of the effect of reservoirs on greenhouse-gas emissions to the atmosphere, is analyzed. It is recommended that greenhouse- gas emissions from various reservoirs be assessed by the procedure “GHG Measurement Guidelines for Fresh Water Reservoirs” (2010) for the purpose of creating a data base with results of standardized measurements. Aprogram for research into greenhouse-gas emissions is being developed at the St. Petersburg Polytechnic University in conformity with the IHA procedure at the reservoirs impounded by the Sayano-Shushenskaya and Mainskaya HPP operated by the RusHydro Co.

The greenhouse advantage of natural gas appliances

International Nuclear Information System (INIS)

Coombe, N.

2000-01-01

The life cycle report prepared recently by Energetics for the AGA, Assessment of Greenhouse Gas Emissions from Natural Gas, demonstrates clearly the greenhouse advantage natural gas has over coal in generating electricity. This study also goes one step further in applying this life cycle approach to the use of space and water heating within the home. The study shows the significant green-house advantage that natural gas appliances have over electric appliances. Findings from other studies also support this claim. The natural gas suppliers are encouraged to take advantage of the marketing opportunity that these studies provide, offering the householders the fuel that will significantly reduce their contribution to greenhouse emission

Effects of agrochemicals, ultra violet stabilisers and solar radiation on the radiometric properties of greenhouse films

Directory of Open Access Journals (Sweden)

Giuliano Vox

2013-10-01

Full Text Available Agrochemicals, based on iron, sulphur and chlorine, generate by products that lead to a degradation of greenhouse films together with a decrease in their mechanical and physical properties. The degradation due to agrochemicals depends on their active principles, method and frequency of application, and greenhouse ventilation. The aim of the research was to evaluate how agrochemical contamination and solar radiation influence the radiometric properties of ethylene-vinyl acetate copolymer greenhouse films by means of laboratory and field tests. The films, manufactured on purpose with the addition of different light stabiliser systems, were exposed to natural outdoor weathering at the experimental farm of the University of Bari (Italy; 41° 05’ N in the period from 2006 to 2008. Each film was tested for two low tunnels: one low tunnel was sprayed from inside with the agrochemicals containing iron, chlorine and sulphur while the other one was not sprayed and served as control. Radiometric laboratory tests were carried out on the new films and on samples taken at the end of the trials. The experimental tests showed that both the natural weathering together with the agrochemicals did not modify significantly the radiometric properties of the films in the solar and in the photosynthetically active radiation wavelength range. Within six months of experimental field tests the variations in these radiometric characteristics were at most 10%. Significant variations, up to 70% of the initial value, were recorded for the stabilised films in the long-wave infrared radiation wavelength range.

Greenhouse engineering: New technologies and approaches

NARCIS (Netherlands)

Montero, J.I.; Henten, van E.J.; Son, J.E.; Castilla, N.

2011-01-01

Firstly, this article discusses the greenhouse engineering situation in three geographic areas which are relevant in the field of protected cultivation: Northern Asia, The Netherlands and the Mediterranean. For each area, the prevailing greenhouse type and equipment is briefly described. Secondly,

The Greenhouse Effect: Science and Policy.

Science.gov (United States)

Schneider, Stephen H.

1989-01-01

Discusses many of the scientific questions surrounding the greenhouse effect debate and the issue of plausible responses. Discussion includes topics concerning projecting emissions and greenhouse gas concentrations, estimating global climatic response, economic, social, and political impacts, and policy responses. (RT)

75 FR 18455 - Mandatory Reporting of Greenhouse Gases

Science.gov (United States)

2010-04-12

... Mandatory Reporting of Greenhouse Gases AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule amendment. SUMMARY: EPA is proposing to amend the Mandatory Greenhouse Gas (GHG) Reporting Rule, to require.... The Mandatory GHG Reporting Rule requires greenhouse gas emitting facilities and suppliers of fuels...

Evaluation of new reference genes in papaya for accurate transcript normalization under different experimental conditions.

Directory of Open Access Journals (Sweden)

Xiaoyang Zhu

Full Text Available Real-time reverse transcription PCR (RT-qPCR is a preferred method for rapid and accurate quantification of gene expression studies. Appropriate application of RT-qPCR requires accurate normalization though the use of reference genes. As no single reference gene is universally suitable for all experiments, thus reference gene(s validation under different experimental conditions is crucial for RT-qPCR analysis. To date, only a few studies on reference genes have been done in other plants but none in papaya. In the present work, we selected 21 candidate reference genes, and evaluated their expression stability in 246 papaya fruit samples using three algorithms, geNorm, NormFinder and RefFinder. The samples consisted of 13 sets collected under different experimental conditions, including various tissues, different storage temperatures, different cultivars, developmental stages, postharvest ripening, modified atmosphere packaging, 1-methylcyclopropene (1-MCP treatment, hot water treatment, biotic stress and hormone treatment. Our results demonstrated that expression stability varied greatly between reference genes and that different suitable reference gene(s or combination of reference genes for normalization should be validated according to the experimental conditions. In general, the internal reference genes EIF (Eukaryotic initiation factor 4A, TBP1 (TATA binding protein 1 and TBP2 (TATA binding protein 2 genes had a good performance under most experimental conditions, whereas the most widely present used reference genes, ACTIN (Actin 2, 18S rRNA (18S ribosomal RNA and GAPDH (Glyceraldehyde-3-phosphate dehydrogenase were not suitable in many experimental conditions. In addition, two commonly used programs, geNorm and Normfinder, were proved sufficient for the validation. This work provides the first systematic analysis for the selection of superior reference genes for accurate transcript normalization in papaya under different experimental

Energy use pattern analyses of greenhouse vegetable production

Energy Technology Data Exchange (ETDEWEB)

Canakci, M.; Akinci, I. [Department of Agricultural Machinery, Faculty of Agriculture, Akdeniz University, 07070 Antalya (Turkey)

2006-07-15

Greenhouse farming is a growing industry in many states. It is a very expensive way to produce greenhouse crops and there are many variables to consider before the farmer decides to take this route. A good location is essential for crop planning and growing. However, current studies related to energy use patterns and resources present in vegetable production are very limited. This research attempts to investigate the energy use patterns in greenhouse vegetable production, to determine the energy output-input ratio and their relationships. Antalya province, which has greenhouse area of about 13,337ha (30.2%), is the center of greenhouse farming in Turkey. A questionnaire was distributed to 101 greenhouse farms from 11 villages in order to obtain the available data for vegetable production. Power requirement of the machines used in greenhouse operations were measured by using a computer based data acquisition system. Energy and economical variables (i.e. output-input ratio, specific energy, production cost, net return, etc.) were calculated by using the standard equations. As a result, the operational energy and energy source requirements of the greenhouse vegetable production were found between the ranges of 23,883.5-28,034.7 and 45,763.3-49,978.8MJ/1000m{sup 2}, respectively. The energy ratio of four major greenhouse vegetables-tomato, pepper, cucumber and eggplant-was 0.32, 0.19, 0.31, 0.23, respectively. The crop yields increased as a function of the total energy inputs with the best form being second-degree polynomial. The net return of the vegetable production was found in the 595.6-2775.3$/1000m{sup 2} ranges. Among the greenhouse vegetables, tomato cultivation resulted in being the most profitable. (author)

Predicting sublethal effects of herbicides on terrestrial non-crop plant species in the field from greenhouse data

International Nuclear Information System (INIS)

Riemens, Marleen M.; Dueck, Thom; Kempenaar, Corne

2008-01-01

Guidelines provided by OECD and EPPO allow the use of data obtained in greenhouse experiments in the risk assessment for pesticides to non-target terrestrial plants in the field. The present study was undertaken to investigate the predictability of effects on field-grown plants using greenhouse data. In addition, the influence of plant development stage on plant sensitivity and herbicide efficacy, the influence of the surrounding vegetation on individual plant sensitivity and of sublethal herbicide doses on the biomass, recovery and reproduction of non-crop plants was studied. Results show that in the future, it might well be possible to translate results from greenhouse experiments to field situations, given sufficient experimental data. The results also suggest consequences at the population level. Even when only marginal effects on the biomass of non-target plants are expected, their seed production and thereby survival at the population level may be negatively affected. - The response of greenhouse-grown wild plant species to herbicide exposure could be related to the response of the same species when grown in the field

Greenhouse gas emissions from food and garden waste composting

OpenAIRE

Ermolaev, Evgheni

2015-01-01

Composting is a robust waste treatment technology. Use of finished compost enables plant nutrient recycling, carbon sequestration, soil structure improvement and mineral fertiliser replacement. However, composting also emits greenhouse gases (GHG) such as methane (CH₄) and nitrous oxide (N₂O) with high global warming potential (GWP). This thesis analysed emissions of CH₄ and N₂O during composting as influenced by management and process conditions and examined how these emissions could be ...

75 FR 66433 - Mandatory Reporting of Greenhouse Gases

Science.gov (United States)

2010-10-28

... Part II Environmental Protection Agency 40 CFR Parts 86 and 98 Mandatory Reporting of Greenhouse...; FRL-9213-5] RIN 2060-A079 Mandatory Reporting of Greenhouse Gases AGENCY: Environmental Protection... Mandatory Greenhouse Gas Reporting rule to correct certain technical and editorial errors that have been...

75 FR 33949 - Mandatory Reporting of Greenhouse Gases

Science.gov (United States)

2010-06-15

... Part III Environmental Protection Agency 40 CFR Parts 86 and 98 Mandatory Reporting of Greenhouse...; FRL-9158-6] RIN 2060-A079 Mandatory Reporting of Greenhouse Gases AGENCY: Environmental Protection... Final Mandatory Greenhouse Gas Reporting rule (2009 Final MRR) to correct certain technical and...

75 FR 48743 - Mandatory Reporting of Greenhouse Gases

Science.gov (United States)

2010-08-11

... Part II Environmental Protection Agency 40 CFR Part 98 Mandatory Reporting of Greenhouse Gases...-AQ33 Mandatory Reporting of Greenhouse Gases AGENCY: Environmental Protection Agency (EPA). ACTION... Greenhouse Gas Reporting Rule Hotline at telephone number: (877) 444-1188; or e-mail: [email protected] . To...

The solar greenhouse : a highly insulated greenhouse design with an inflated roof system with PVDF or ETFE membranes

OpenAIRE

Waaijenberg, D.; Hemming, S.; Campen, J.B.

2005-01-01

In a co-operation project of Wageningen University (Wageningen UR), Agrotechnology & Food Innovations B.V. (A&F), Priva Hortimation B.V. and Hyplast N.V. (Belgium) a greenhouse for the future has been developed. The project has four lines, namely 1. lowering the energy demand, 2. using solar energy for heating (greenhouse as solar collector), 3. modifying climate control and dehumidification and 4. developing of the highly insulated greenhouse. This paper deals with the development of...

Low Simulated Radiation Limit for Runaway Greenhouse Climates

Science.gov (United States)

Goldblatt, Colin; Robinson, Tyler D.; Zahnle, Kevin J.; Crisp, David

2013-01-01

Terrestrial planet atmospheres must be in long-term radiation balance, with solar radiation absorbed matched by thermal radiation emitted. For hot moist atmospheres, however, there is an upper limit on the thermal emission which is decoupled from the surface temperature. If net absorbed solar radiation exceeds this limit the planet will heat uncontrollably, the so-called \\runaway greenhouse". Here we show that a runaway greenhouse induced steam atmosphere may be a stable state for a planet with the same amount of incident solar radiation as Earth has today, contrary to previous results. We have calculated the clear-sky radiation limits at line-by-line spectral resolution for the first time. The thermal radiation limit is lower than previously reported (282 W/sq m rather than 310W/sq m) and much more solar radiation would be absorbed (294W/sq m rather than 222W/sq m). Avoiding a runaway greenhouse under the present solar constant requires that the atmosphere is subsaturated with water, and that cloud albedo forcing exceeds cloud greenhouse forcing. Greenhouse warming could in theory trigger a runaway greenhouse but palaeoclimate comparisons suggest that foreseeable increases in greenhouse gases will be insufficient to do this.

Greenhouse gas emissions from hydroelectric reservoirs

International Nuclear Information System (INIS)

Rosa, L.P.; Schaeffer, R.

1994-01-01

In a recent paper, Rudd et al. have suggested that, per unit of electrical energy produced, greenhouse-gas emissions from some hydroelectric reservoirs in northern Canada may be comparable to emissions from fossil-fuelled power plants. The purpose of this comment is to elaborate these issues further so as to understand the potential contribution of hydroelectric reservoirs to the greenhouse effect. More than focusing on the total budget of carbon emissions (be they in the form of CH 4 or be they in the form of CO 2 ), this requires an evaluation of the accumulated greenhouse effect of gas emissions from hydroelectric reservoirs and fossil-fuelled power plants. Two issues will be considered: (a) global warming potential (GWP) for CH 4 ; and (b) how greenhouse-gas emissions from hydroelectric power plants stand against emissions from fossil-fuelled power plants with respect to global warming

Greenhouse gas microbiology in wet and dry straw crust covering pig slurry

DEFF Research Database (Denmark)

Hansen, Rikke Ruth; Nielsen, Daniel Aagren; Schramm, Andreas

2009-01-01

was observed in all crusted treatments exposed to anoxia, and this was probably a result of denitrification based on NO2- and NO3- that had accumulated in the crust during oxic conditions. To reduce overall greenhouse gas emissions, floating crust should be managed to optimize conditions for methanotrophs....... microbiology had an effect on the emission of the potent greenhouse gases CH4 and nitrous oxide (N2O) when crust moisture was manipulated ("Dry", "Moderate", and "Wet"). The dry crust had the deepest oxygen penetration (45 mm as compared to 20 mm in the Wet treatment) as measured with microsensors, the highest...... oxidizing bacteria were undetectable and methane oxidizing bacteria were only sparsely present in the "Wet" treatment. A change to anoxia did not affect the CH4 emission indicating the virtual absence of aerobic methane oxidation in the investigated 2-months old crusts. However, an increase in N2O emission...

Intensity of competition in the market of greenhouse vegetables

Directory of Open Access Journals (Sweden)

Oleg Ivanovich Botkin

2012-03-01

Full Text Available This paper reviews the competitive environment of the market greenhouse vegetables. Revealed specific features of the industry, determining the level of intensity of competition in the market greenhouse vegetables. Classified factors internal and external environment, identify indicators that affect the state of the market. The factors that determine the intensity of competition in the market greenhouse vegetables.The main competitors on the Russian market of greenhouse production.Identified indicators of the intensity level of competition, in particular: the level of monopolization of the market greenhouse vegetables, the level of concentration of production in the industry, the generalized index of the intensity of the competitive environment.Shows a comparative analysis of competitors’ market greenhouse vegetables in Udmurtia.Revealed competitive advantages which can help local producers to reduce the pressure of competition and intra-industry to occupy a leading position in the Russian market of greenhouse vegetable production.The dynamics of economic performance of Russian producers. Ways of improving the competitiveness of enterprises for the production of greenhouse vegetables

The entomopathogenic fungal endophytes Purpureocillium lilacinum (formerly Paecilomyces lilacinus) and Beauveria bassiana negatively affect cotton aphid reproduction under both greenhouse and field conditions.

Science.gov (United States)

Castillo Lopez, Diana; Zhu-Salzman, Keyan; Ek-Ramos, Maria Julissa; Sword, Gregory A

2014-01-01

endophytes for the biological control of aphids and other herbivores under greenhouse and field conditions.

The entomopathogenic fungal endophytes Purpureocillium lilacinum (formerly Paecilomyces lilacinus and Beauveria bassiana negatively affect cotton aphid reproduction under both greenhouse and field conditions.

Directory of Open Access Journals (Sweden)

Diana Castillo Lopez

using these endophytes for the biological control of aphids and other herbivores under greenhouse and field conditions.

Experimental Study on Effect of Operating Conditions on Thermoelectric Power Generation

DEFF Research Database (Denmark)

Mahmoudi Nezhad, Sajjad; Rezaniakolaei, Alireza; Rosendahl, Lasse Aistrup

2017-01-01

Effect of boundary conditions of thermal reservoirs on power generation of thermoelectric modules (TEMs) is examined experimentally. To realize the characteristics of the power generation by the TEMs, the system performance is studied over various volumetric flow rates and flow temperatures...

Greenhouse effects on Venus

Science.gov (United States)

Bell, Peter M.

Calculations that used Pioneer-Venus measurements of atmosphere composition, temperature profiles, and radiative heating predicted Venus' surface temperature ‘very precisely,’ says the Ames Research Center. The calculations predict not only Venus' surface temperature but agree with temperatures measured at various altitudes above the surface by the four Pioneer Venus atmosphere probe craft.Using Pioneer-Venus spacecraft data, a research team has virtually proved that the searing 482° C surface temperature of Venus is due to an atmospheric greenhouse effect. Until now the Venus greenhouse effect has been largely a theory.

Clayey cap-rocks reactivity in presence of CO2 in deep geological storage conditions: experimentation/modeling integrated approach

International Nuclear Information System (INIS)

Credoz, A.

2009-10-01

CO 2 capture, transport and geological storage is one of the main solutions considered in the short and medium term to reduce CO 2 and others greenhouse gases emissions towards the atmosphere, by storing CO 2 in deeper geological reservoirs during 100 to 10 000 years. This Ph-D study offers a multi-scale vision of complex clayey cap-rocks reactivity and evolution. These formations are identified for the CO 2 containment and sealing into the reservoir. From the experimental scale on purified clay minerals to integrative modeling at high space and time scales, the strategy developed allowed identifying the main geochemical processes, to check the good agreement between experiment and modeling, and to lay emphasis the operational impacts on long-term cap-rocks integrity. Carbonated cements alteration is likely to open cap-rock porosity and to create preferential reactive pathway for reactive fluid flow. Besides, this could alter the cap-rock structure and the global geo-mechanic properties. Clay minerals alteration, including the illitization process, reduces the clay fraction volume but considerably limits the porosity increase. The illitization process in acidic conditions determined experimentally and by modeling at low and high scale, is coupled with silica precipitation. The final porosity increase control results of these two reactive processes balance. By a fundamental side, this study reveals new kinetic parameters of clay minerals and highlights new structural transformations. By an operational side, this study contributes to the acquisition of qualitative data (long-term reactive pathways of clayey cap-rocks, coupled reactivity carbonates/clays) and quantitative data (CO 2 penetration distance into the cap-rock) to partly answer to the performance and safety assessment CO 2 capture and geological storage. (author)

Study of soil-plant transfer of {sup 226}Ra under greenhouse conditions

Energy Technology Data Exchange (ETDEWEB)

Soudek, Petr; Petrova, Sarka [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Drnovska 507, 161 06 Prague 6 (Czech Republic); Benesova, Dagmar; Kotyza, Jan [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Drnovska 507, 161 06 Prague 6 (Czech Republic); Faculty of Environment Technology, Institute of Chemical Technology, Technicka 5, 166 28 Prague 6 (Czech Republic); Vagner, Martin [Laboratory of Biologically Active Compounds, Institute of Experimental Botany AS CR, v.v.i., Rozvojova 263, Prague 6 (Czech Republic); Vankova, Radomira [Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany AS CR, v.v.i., Rozvojova 263, Prague 6 (Czech Republic); Vanek, Tomas, E-mail: vanek@ueb.cas.c [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Drnovska 507, 161 06 Prague 6 (Czech Republic)

2010-06-15

A soil-plant transfer study was performed using soil from a former uranium ore processing factory in South Bohemia. We present the results from greenhouse experiments which include estimates of the time required for phytoremediation. The accumulation of {sup 226}Ra by different plant species from a mixture of garden soil and contaminated substrate was extremely variable, ranging from 0.03 to 2.20 Bq {sup 226}Ra/g DW. We found differences in accumulation of {sup 226}Ra between plants from the same genus and between cultivars of the same plant species. The results of {sup 226}Ra accumulation showed a linear relation between concentration of {sup 226}Ra in plants and concentration of {sup 226}Ra in soil mixtures. On the basis of these results we estimated the time required for phytoremediation, but this appears to be too long for practical purposes.

Effects of ground insulation and greenhouse microenvironment on ...

African Journals Online (AJOL)

A study was conducted at Egerton University, Njoro, Kenya to establish the potential of plastic digester to produce biogas under natural and greenhouse microenvironment. The specific objectives were to evaluate the effects of greenhouse and ground insulation on the rate and quality of biogas generation. A greenhouse ...

76 FR 73885 - Mandatory Reporting of Greenhouse Gases

Science.gov (United States)

2011-11-29

... Mandatory Reporting of Greenhouse Gases; Final Rule #0;#0;Federal Register / Vol. 76, No. 229 / Tuesday... 98 [EPA-HQ-OAR-2011-0147; FRL-9493-9] RIN 2060-AQ85 Mandatory Reporting of Greenhouse Gases AGENCY... the Mandatory Reporting of Greenhouse Gases Rule to correct certain technical and editorial errors...

76 FR 47391 - Mandatory Reporting of Greenhouse Gases

Science.gov (United States)

2011-08-04

... Mandatory Reporting of Greenhouse Gases; Proposed Rule #0;#0;Federal Register / Vol. 76, No. 150 / Thursday...-HQ-OAR-2011-0147; FRL-9443-1] RIN 2060-AQ85 Mandatory Reporting of Greenhouse Gases AGENCY... provisions in the Mandatory Reporting of Greenhouse Gases Rule to correct certain technical and editorial...

Energy market reform and greenhouse gas emission reductions

International Nuclear Information System (INIS)

Anon.

1999-01-01

The report reviews micro-economic reform in the energy market and measures the impact that energy market reform is expected to have on greenhouse gas outcomes. It indicates that reform in the electricity and gas industries is delivering what was promised, an efficient market with lower energy prices and, over the longer term, will deliver a gradually reducing rate of greenhouse gas emissions per unit of energy produced. It also recognises that energy market reform has removed some barriers to the entry of less greenhouse gas intense fuels. These trends will result in reduced greenhouse gas intensity in the supply of energy and significant reductions in the growth in greenhouse gas emissions compared to what may have been expected without the reforms

Effect of phase change materials on indoor thermal environment under different weather conditions and over a long time

International Nuclear Information System (INIS)

Ling, Haoshu; Chen, Chao; Wei, Shen; Guan, Yong; Ma, Caiwen; Xie, Guangya; Li, Na; Chen, Ziguang

2015-01-01

Highlights: • Indicators evaluating the performance of PCMs in greenhouses are introduced. • Real equivalent specific heat capacity of PCMs is embedded in a numerical model. • Real behaviour of PCMs has been monitored over a long time. • Efficiency of PCMs walls are compared for sunny and cloudy days. • Heat storage and release amounts of PCMs walls have been calculated. - Abstract: To evaluate the effect of phase change materials (PCMs) on the indoor thermal environment of greenhouses under different weather conditions and over a long time in the heating season, a study was carried out using both experimental method and numerical method. The study was conducted in a typical greenhouse located in Beijing, China, and important parameters have been monitored continuously for 61 days, including indoor air temperature, outdoor air temperature, solar radiation, surface temperature of greenhouse envelopes and soil temperature. Based on these parameters, a number of indicators, namely, operative temperature, daily effective accumulative temperature, irradiated surface temperature of the north wall, average temperature of PCMs, and daily heat storage and release, have been used to evaluate the performance of PCMs in greenhouses. All indicators have provided consistent results that confirm the positive effect of PCMs on improving the indoor thermal environment of greenhouses over a long time. Additionally, the paper has demonstrated that a sunny weather could help to promote the efficiency of PCMs, comparing to a cloudy weather

Scientists' internal models of the greenhouse effect

Science.gov (United States)

Libarkin, J. C.; Miller, H.; Thomas, S. R.

2013-12-01

A prior study utilized exploratory factor analysis to identify models underlying drawings of the greenhouse effect made by entering university freshmen. This analysis identified four archetype models of the greenhouse effect that appear within the college enrolling population. The current study collected drawings made by 144 geoscientists, from undergraduate geoscience majors through professionals. These participants scored highly on a standardized assessment of climate change understanding and expressed confidence in their understanding; many also indicated that they teach climate change in their courses. Although geoscientists held slightly more sophisticated greenhouse effect models than entering freshmen, very few held complete, explanatory models. As with freshmen, many scientists (44%) depict greenhouse gases in a layer in the atmosphere; 52% of participants depicted this or another layer as a physical barrier to escaping energy. In addition, 32% of participants indicated that incoming light from the Sun remains unchanged at Earth's surface, in alignment with a common model held by students. Finally, 3-20% of scientists depicted physical greenhouses, ozone, or holes in the atmosphere, all of which correspond to non-explanatory models commonly seen within students and represented in popular literature. For many scientists, incomplete models of the greenhouse effect are clearly enough to allow for reasoning about climate change. These data suggest that: 1) better representations about interdisciplinary concepts, such as the greenhouse effect, are needed for both scientist and public understanding; and 2) the scientific community needs to carefully consider how much understanding of a model is needed before necessary reasoning can occur.

Optimal control of a solar greenhouse

NARCIS (Netherlands)

Ooteghem, van R.J.C.; Stigter, J.D.; Willigenburg, van L.G.; Straten, van G.

2003-01-01

A solar greenhouse has been designed that maximizes solar energy use and minimizes fossil energy consumption. It is based on a conventional greenhouse extended with a heat pump, a heat exchanger, an aquifer and ventilation with heat recovery. The aim is to minimize fossil energy consumption, while

Governance Mechanism for Global Greenhouse Gas Emissions: A Stochastic Differential Game Approach

Directory of Open Access Journals (Sweden)

Wei Yu

2013-01-01

Full Text Available Today developed and developing countries have to admit the fact that global warming is affecting the earth, but the fundamental problem of how to divide up necessary greenhouse gas reductions between developed and developing countries remains. In this paper, we propose cooperative and noncooperative stochastic differential game models to describe greenhouse gas emissions decision makings of developed and developing countries, calculate their feedback Nash equilibrium and the Pareto optimal solution, characterize parameter spaces that developed and developing countries can cooperate, design cooperative conditions under which participants buy the cooperative payoff, and distribute the cooperative payoff with Nash bargaining solution. Lastly, numerical simulations are employed to illustrate the above results.

Applied research and implementation of microbial control agents for pest control: greenhouse crops

Science.gov (United States)

Greenhouse crop production has experienced strong growth in recent decades, reaching nearly 4 million hectare in 2010. Due to favorable environmental conditions and constant availability of host plants, arthropod pests are a major production constraint that has elicited parallel increases in pestici...

Structural analysis and functional characteristics of greenhouses in ...

African Journals Online (AJOL)

... resulting from loads acting on beams of each greenhouse, were analyzed by SAP2000 program. Also, the stretch ratios as per whether greenhouse types and covering materials have a statistically significant effect were examined. According to the obtained data, it was found that all of the selected greenhouses could not

Greenhouse gas emissions related to Dutch food consumption

NARCIS (Netherlands)

Kramer, KJ; Moll, HC; Nonhebel, S; Wilting, HC

The consumption of food products involves emissions of greenhouse gases. Emissions occur in the various stages of the life cycle of food products. In this paper we discuss the greenhouse gas emissions, CO2, CH4, and N2O, related to Dutch household food consumption. Combinations of greenhouse gas

Technologies for a greenhouse-constrained society

International Nuclear Information System (INIS)

Kuliasha, M.A.; Zucker, A.; Ballew, K.J.

1992-01-01

This conference explored how three technologies might help society adjust to life in a greenhouse-constrained environment. Technology experts and policy makers from around the world met June 11--13, 1991, in Oak Ridge, Tennessee, to address questions about how energy efficiency, biomass, and nuclear technologies can mitigate the greenhouse effect and to explore energy production and use in countries in various stages of development. The conference was organized by Oak Ridge National Laboratory and sponsored by the US Department of Energy. Energy efficiency biomass, and nuclear energy are potential substitutes for fossil fuels that might help slow or even reverse the global warming changes that may result from mankind's thirst for energy. Many other conferences have questioned whether the greenhouse effect is real and what reductions in greenhouse gas emissions might be necessary to avoid serious ecological consequences; this conference studied how these reductions might actually be achieved. For these conference proceedings, individuals papers are processed separately for the Energy Data Base

Second Greenhouse Gas Information System Workshop

Science.gov (United States)

Boland, S. W.; Duren, R. M.; Mitchiner, J.; Rotman, D.; Sheffner, E.; Ebinger, M. H.; Miller, C. E.; Butler, J. H.; Dimotakis, P.; Jonietz, K.

2009-12-01

The second Greenhouse Gas Information System (GHGIS) workshop was held May 20-22, 2009 at the Sandia National Laboratories in Albuquerque, New Mexico. The workshop brought together 74 representatives from 28 organizations including U.S. government agencies, national laboratories, and members of the academic community to address issues related to the understanding, operational monitoring, and tracking of greenhouse gas emissions and carbon offsets. The workshop was organized by an interagency collaboration between NASA centers, DOE laboratories, and NOAA. It was motivated by the perceived need for an integrated interagency, community-wide initiative to provide information about greenhouse gas sources and sinks at policy-relevant temporal and spatial scales in order to significantly enhance the ability of national and regional governments, industry, and private citizens to implement and evaluate effective climate change mitigation policies. This talk provides an overview of the second Greenhouse Gas Information System workshop, presents its key findings, and discusses current status and next steps in this interagency collaborative effort.

Microclimatic changes caused by different plastic coverings in greenhouses cultivated with cherry tomato in southern Brazil

Directory of Open Access Journals (Sweden)

Ester Holcman

2015-06-01

Full Text Available In regions with intense solar radiation it is common the use of aluminated covers in greenhouses, with the aim of reducing the inside temperature. However, the use of these covers reduces photosynthetic active radiation (PAR transmitted into the greenhouse. The objective of the present study was to evaluate the influence of different covers on microclimate in greenhouses cultivated with cherry tomato during three growing seasons. The environment I was covered with plastic film anti-UV and with thermo-reflective screen (40% disposed internally. The environment II was covered with diffusive plastic film (55%. The transmitted solar radiation to the interior of covered environments was, on average, 5.5 MJ m-2 day-1 in the environment I and 8.2 MJ m-2 day-1 in environment II. The air temperature in environment II was, on average, 1°C higher than external conditions. The highest difference for the relative humidity (RH was also observed between environment II and the outside conditions, with 10.7% for the minimum RH during the first growing period. Considering all growing periods, the diffusive plastic film provided higher solar energy availability inside the greenhouse than the plastic film with thermo-reflective screen, without causing major changes in air temperature and relative humidity, and promoting greater productivity of tomato grown under this environment for the three periods evaluated.

Greenhouse gas emissions of Dutch biomass. Quantification of greenhouse gases emission of Dutch biomass for electricity and heat

International Nuclear Information System (INIS)

Koop, K.; Yildiz, I.

2010-09-01

The greenhouse gas emissions of all available flows of the biomass chain have been established. This report has the following aims: (1) to establish the greenhouse gas emission of Dutch biomass available for generating electricity and heat; (2) to obtain insight in the opportunities and threats for using the potential of the biomass chains that have the highest potential to reduce greenhouse gas emissions. This report can be seen as a supplement to the report 'Availability of Dutch biomass for electricity and heat in 2020' (2009) [nl

Runaway greenhouse atmospheres: Applications to Earth and Venus

International Nuclear Information System (INIS)

Kasting, J.F.

1991-01-01

Runaway greenhouse atmospheres are discussed from a theoretical standpoint and with respect to various practical situation in which they might occur. The following subject areas are covered: (1) runaway greenhouse atmospheres; (2) moist greenhouse atmospheres; (3) loss of water from Venus; (4) steam atmosphere during accretion; and (5) the continuously habitable zone

Runaway greenhouse atmospheres: Applications to Earth and Venus

Science.gov (United States)

Kasting, James F.

1991-01-01

Runaway greenhouse atmospheres are discussed from a theoretical standpoint and with respect to various practical situation in which they might occur. The following subject areas are covered: (1) runaway greenhouse atmospheres; (2) moist greenhouse atmospheres; (3) loss of water from Venus; (4) steam atmosphere during accretion; and (5) the continuously habitable zone.

Experimental Aspects in the Vibration-Based Condition Monitoring of Large Hydrogenerators

Directory of Open Access Journals (Sweden)

Geraldo Carvalho Brito Junior

2017-01-01

Full Text Available Based on experimental observations on a set of twenty 700 MW hydrogenerators, compiled from several technical reports issued over the last three decades and collected from the reprocessing of the vibration signals recorded during the last commissioning tests, this paper shows that the accurate determination of the journal bearings operating conditions may be a difficult task. It shows that the outsize bearing brackets of large hydrogenerators are subject to substantial dimensional changes caused by external agents, like the generator electromagnetic field and the bearing cooling water temperature. It also shows that the shaft eccentricity of a journal bearing of a healthy large hydrogenerator, operating in steady-state condition, may experience unpredictable, sudden, and significant changes without apparent reasons. Some of these phenomena are reproduced in ordinary commissioning tests or may be noticed even during normal operation, while others are rarely observed or are only detected through special tests. These phenomena modify journal bearings stiffness and damping, changing the hydrogenerator dynamics, creating discrepancies between theoretical predictions and experimental measurements, and making damage detection and diagnostics difficult. Therefore, these phenomena must be analyzed and considered in the application of vibration-based condition monitoring to these rotating machines.

R W Wood's Experiment Done Right - A Laboratory Demonstration of the Greenhouse Effect

Science.gov (United States)

Halpern, J. B.

2016-12-01

It would not be exaggerating to say that R. W. Wood was the most respected experimental optical physicist of his time. Thus the null result of his attempt to demonstrate the greenhouse effect by comparing temperature rise in illuminated cylinders with glass or rock salt windows has echoed down through the years in climate science discussions both on the professional and public levels1. Today the web is full of videos purporting to demonstrate the greenhouse effect, but careful examination shows that they simply demonstrate heating via absorption of IR or NIR light by CO2. These experiments miss that the greenhouse effect is a result of the temperature difference between the surface and the upper troposphere as a result of which radiation from greenhouse molecules slows as the level rises. The average distance a photon emitted from a vibrationally excited CO2 molecule is about 10 m at the surface, increasing with altitude until at about 8 km the mean free path allows for radiation to space. Increasing CO2 concentrations raises this level to a higher one, which is colder, and at which the rate of radiation to space decreases. Emitting the same amount of radiation to space as before requires heating the entire system including the surface. To model the greenhouse effect we have used a 22 L bulb with a capsule heater in the center. The temperature near the heater (the surface) or above it can be monitored using a thermocouple and the CO2 mixing ratio determined using a NDIR sensor. By controlling the CO2 concentration in the bulb, the mean free path of re-radiated photons from CO2 can be controlled so that it much smaller than the bulb's diameter. We have measure rises in temperature both near the heater and at a distance from it as CO2is introduced, demonstrating the greenhouse effect. 1. R.W. Wood, London, Edinborough and Dublin Philosophical Magazine , 1909, 17, p319-320 also http://www.wmconnolley.org.uk/sci/wood_rw.1909.html

Reflections on greenhouse gas life cycle assessment

International Nuclear Information System (INIS)

Jarrell, J.; Phillips, B.; Pendergast, D.

1999-01-01

The amount of carbon dioxide equivalent greenhouse gas emitted per unit of electricity produced is an important consideration in the planning of future greenhouse gas reduced electricity supply systems. Useful estimates of emissions must also take into account the entire cradle to grave life cycle emissions of alternative systems. Thus emissions of greenhouse gases take into account all of the components of building operating, and decommissioning facilities. This requires an accounting of emissions from production of all materials used to build the plants, transportation of materials to the site as well as fuels used for their construction, operation, and decommissioning. The construction of facilities may also have effects which tend to affect greenhouse gas emissions through modification of the local environment. A notable example, often cited, is the evolution of methane from the decay of organic matter submerged by dams built to serve hydro power facilities. In the long term, we anticipate that some kind of cost will be associated with the release of greenhouse gases. In that event it may be argued that the modified economic system established by inclusion of this cost will naturally control the emission of greenhouse gases from competing means of electricity production. Greenhouse gas emissions from all stages involved in the birth and retirement of electricity producing plant could be suitably constrained as the least cost method of production is sought. Such an ideal system is far from in place. At this point in time the results of life cycle accounting of greenhouse gas emissions are a needed means of comparing emissions from alternative sources of electricity. Many life cycle studies have been undertaken in the past. Many of the estimates are based on past practice which does not take into account any possible need to limit the production of greenhouse gas during the design of the plant and operational processes. Sources of energy used to produce materials

Alternatives to Outdoor Daylight Illumination for Photodynamic Therapy—Use of Greenhouses and Artificial Light Sources

Directory of Open Access Journals (Sweden)

Catharina M. Lerche

2016-02-01

Full Text Available Daylight-mediated photodynamic therapy (daylight PDT is a simple and pain free treatment of actinic keratoses. Weather conditions may not always allow daylight PDT outdoors. We compared the spectrum of five different lamp candidates for indoor “daylight PDT” and investigated their ability to photobleach protoporphyrin IX (PpIX. Furthermore, we measured the amount of PpIX activating daylight available in a glass greenhouse, which can be an alternative when it is uncomfortable for patients to be outdoors. The lamps investigated were: halogen lamps (overhead and slide projector, white light-emitting diode (LED lamp, red LED panel and lamps used for conventional PDT. Four of the five light sources were able to photobleach PpIX completely. For halogen light and the red LED lamp, 5000 lux could photobleach PpIX whereas 12,000 lux were needed for the white LED lamp. Furthermore, the greenhouse was suitable for daylight PDT since the effect of solar light is lowered only by 25%. In conclusion, we found four of the five light sources and the greenhouse usable for indoor daylight PDT. The greenhouse is beneficial when the weather outside is rainy or windy. Only insignificant ultraviolet B radiation (UVB radiation passes through the greenhouse glass, so sun protection is not needed.

Factorial experimental design intended for the optimization of the alumina purification conditions

Science.gov (United States)

Brahmi, Mounaouer; Ba, Mohamedou; Hidri, Yassine; Hassen, Abdennaceur

2018-04-01

The objective of this study was to determine the optimal conditions by using the experimental design methodology for the removal of some impurities associated with the alumina. So, three alumina qualities of different origins were investigated under the same conditions. The application of full-factorial designs on the samples of different qualities of alumina has followed the removal rates of the sodium oxide. However, a factorial experimental design was developed to describe the elimination of sodium oxide associated with the alumina. The experimental results showed that chemical analyze followed by XRF prior treatment of the samples, provided a primary idea concerning these prevailing impurities. Therefore, it appeared that the sodium oxide constituted the largest amount among all impurities. After the application of experimental design, analysis of the effectors different factors and their interactions showed that to have a better result, we should reduce the alumina quantity investigated and by against increase the stirring time for the first two samples, whereas, it was necessary to increase the alumina quantity in the case of the third sample. To expand and improve this research, we should take into account all existing impurities, since we found during this investigation that the levels of partial impurities increased after the treatment.

A microclimate model to investigate greenhouse warming of a sub- Alpine ecosystem

International Nuclear Information System (INIS)

Shen, K.P.

1992-01-01

Increasing concentrations of greenhouse gases in the earth's atmosphere are expected to result in a global warming of several degrees Celsius in the coming decades. This warming will have far-reaching impacts on the biosphere, and while General Circulation Models (GCMs) try to predict the magnitude and scope of the warming, there is little information regarding the potential impacts of greenhouse warming on natural systems. An experiment currently under way in a meadow in the Colorado Rocky Mountains attempts to investigate the many consequences of greenhouse warming for soil ecosystems. A mathematical model of the soil microclimate was developed to simulate the soil temperature and moisture content of the meadow. The model simulates both treatment and control scenarios so as to investigate the potential effects of warming. Results of model simulation studies indicate warmer, drier soils under treatment conditions, with the greatest temperature effects of warming occurring at night. These results could have several implications regarding the dynamics of the ecosystem, and future model studies will investigate these connections

The effect of growth conditions on flavonols and anthocyanins accumulation in green and red lettuce

Directory of Open Access Journals (Sweden)

Klaudia BRÜCKOVÁ

2016-12-01

Full Text Available The aim of the study was to investigate the effect of different growth conditions on anthocyanins and flavonols accumulation in leaves of green and red loose leaf lettuce (Lactuca sativa var. crispa. Lettuce plants were grown in three types of conditions, in greenhouse (I. variant, behind clear glass in field (II. variant and in open field conditions (III. variant. Estimation of anthocyanins and flavonols content was done by non-destructive measurements with optical fluorescence sensor Multiplex® 3 (Force-A, France. It was estimated that green lettuce varieties had a greater flavonols content compared to red lettuce varieties in all experimental variants. The highest level of flavonols was detected in leaves of green variety Zoltán (1.218 RU and in red lettuce had the highest amount of flavonols in variety Carmesi (1.095 RU. At the same time red lettuce varieties were characterized by higher anthocyanins content. Parameter anthocyanin index is correlated with visible red coloration of leaves. The highest content of anthocyanins was detected in variety Oakly (0.867 RU. Under the open field conditions was found statistically significant higher (P < 0.05 flavonols and anthocyanins level in both green and red lettuce leaves compared to greenhouse conditions. It may be connected with intensification of flavonoids biosynthesis and accumulation which normally stimulated by sun irradiation, especially UV-B radiation.

Urban Options Solar Greenhouse Demonstration Project. Final report

Energy Technology Data Exchange (ETDEWEB)

Cipparone, L.

1980-10-15

The following are included: the design process, construction, thermal performance, horticulture, educational activities, and future plans. Included in appendices are: greenhouse blueprints, insulating curtain details, workshop schedules, sample data forms, summary of performance calculations on the Urban Options Solar Greenhouse, data on vegetable production, publications, news articles on th Solar Greenhouse Project, and the financial statement. (MHR)

The use of artificial wetlands to treat greenhouse effluents

OpenAIRE

Lévesque, Vicky; Dorais, Martine; Gravel, Valérie; Ménard, Claudine; Antoun, Hani; Rochette, Philippe; Roy, Stéphane

2011-01-01

Untreated greenhouse effluents or leak solution constitute a major environmental burden because their nitrate and phosphate concentrations may induce eutrophication. Artificial wetlands may offer a low cost alternative treatment of greenhouse effluents and consequently improve the sustainability of greenhouse growing systems. The objectives of this study were to 1) characterize the efficiency of different types of wetland to reduce ion content of greenhouse tomato effluent, and 2) improve the...

The Greenhouse Effect Does Exist!

OpenAIRE

Ebel, Jochen

2009-01-01

In particular, without the greenhouse effect, essential features of the atmospheric temperature profile as a function of height cannot be described, i.e., the existence of the tropopause above which we see an almost isothermal temperature curve, whereas beneath it the temperature curve is nearly adiabatic. The relationship between the greenhouse effect and observed temperature curve is explained and the paper by Gerlich and Tscheuschner [arXiv:0707.1161] critically analyzed. Gerlich and Tsche...

Energy demand hourly simulations and energy saving strategies in greenhouses for the Mediterranean climate

Science.gov (United States)

Priarone, A.; Fossa, M.; Paietta, E.; Rolando, D.

2017-01-01

This research has been devoted to the selection of the most favourable plant solutions for ventilation, heating and cooling, thermo-hygrometric control of a greenhouse, in the framework of the energy saving and the environmental protection. The identified plant solutions include shading of glazing surfaces, natural ventilation by means of controlled opening windows, forced convection of external air and forced convection of air treated by the HVAC system for both heating and cooling. The selected solution combines HVAC system to a Ground Coupled Heat Pump (GCHP), which is an innovative renewable technology applied to greenhouse buildings. The energy demand and thermal loads of the greenhouse to fulfil the requested internal design conditions have been evaluated through an hourly numerical simulation, using the Energy Plus (E-plus) software. The overall heat balance of the greenhouse also includes the latent heat exchange due to crop evapotranspiration, accounted through an original iterative calculation procedure that combines the E-plus dynamic simulations and the FAO Penman-Monteith method. The obtained hourly thermal loads have been used to size the borehole field for the geothermal heat pump by using a dedicated GCHP hourly simulation tool.

Chromosome aberrations in pesticide-exposed greenhouse workers

DEFF Research Database (Denmark)

Lander, B F; Knudsen, Lisbeth E.; Gamborg, M O

2000-01-01

OBJECTIVES: The aim of this study was to investigate the possibility of subtoxic exposure to pesticides causing chromosome aberrations in greenhouse workers. METHODS: In a cross-sectional and prospective study design chromosome aberration frequencies in cultured lymphocytes were examined for 116...... greenhouse workers exposed to a complex mixture of almost 50 insecticides, fungicides, and growth regulators and also for 29 nonsmoking, nonpesticide-exposed referents. RESULTS: The preseason frequencies of chromosome aberrations were slightly but not statistically significantly elevated for the greenhouse...... workers when they were compared with the referents. After a summer season of pesticide spraying in the greenhouses, the total frequencies of cells with chromosome aberrations were significantly higher than in the preseason samples (P=0.02) and also higher than for the referents (P=0.05). This finding...

Experimental observation of dynamic ductile damage development under various triaxiality conditions - description of the principle

Directory of Open Access Journals (Sweden)

Pillon L.

2012-08-01

Full Text Available The Gurson model has been extended by Perrin to describe damage evolution in ductile viscoplastic materials. The so-called Gurson-Perrin model allows representing damage development with respect to strain-rate conditions. In order to fill a lack in current experimental procedures, we propose an experimental project able to test and validate the Gurson-Perrin model under various dynamic conditions and for different stress triaxiality levels.

Quantification and Controls of Wetland Greenhouse Gas Emissions

Energy Technology Data Exchange (ETDEWEB)

McNicol, Gavin [Univ. of California, Berkeley, CA (United States)

2016-05-10

Wetlands cover only a small fraction of the Earth’s land surface, but have a disproportionately large influence on global climate. Low oxygen conditions in wetland soils slows down decomposition, leading to net carbon dioxide sequestration over long timescales, while also favoring the production of redox sensitive gases such as nitrous oxide and methane. Freshwater marshes in particular sustain large exchanges of greenhouse gases under temperate or tropical climates and favorable nutrient regimes, yet have rarely been studied, leading to poor constraints on the magnitude of marsh gas sources, and the biogeochemical drivers of flux variability. The Sacramento-San Joaquin Delta in California was once a great expanse of tidal and freshwater marshes but underwent drainage for agriculture during the last two centuries. The resulting landscape is unsustainable with extreme rates of land subsidence and oxidation of peat soils lowering the surface elevation of much of the Delta below sea level. Wetland restoration has been proposed as a means to slow further subsidence and rebuild peat however the balance of greenhouse gas exchange in these novel ecosystems is still poorly described. In this dissertation I first explore oxygen availability as a control on the composition and magnitude of greenhouse gas emissions from drained wetland soils. In two separate experiments I quantify both the temporal dynamics of greenhouse gas emission and the kinetic sensitivity of gas production to a wide range of oxygen concentrations. This work demonstrated the very high sensitivity of carbon dioxide, methane, and nitrous oxide production to oxygen availability, in carbon rich wetland soils. I also found the temporal dynamics of gas production to follow a sequence predicted by thermodynamics and observed spatially in other soil or sediment systems. In the latter part of my dissertation I conduct two field studies to quantify greenhouse gas exchange and understand the carbon sources for

CANDU reactors and greenhouse gas emissions

International Nuclear Information System (INIS)

Andseta, S.; Thompson, M.J.; Jarrell, J.P.; Pendergast, D.R.

1999-01-01

This paper was originally presented at the 11th Pacific Basin Nuclear Conference, Banff, Alberta, Canada, May 3-7, 1998. It has been updated to include additional lifecycle data on chemical releases from ore treatment and CANDU fuel fabrication. It is sometimes stated that nuclear power plants can supply electricity with zero emissions of greenhouse gases. In fact, consideration of the entire fuel cycle indicates that some greenhouse gases are generated during their construction and decommissioning and by the preparation of fuel and other materials required for their operation. This follows from the use of fossil fuels in the preparation of materials and during the construction and decommissioning of the plants. This paper reviews life cycle studies of several different kinds of power plants. Greenhouse gases generated by fossil fuels during the preparation of fuel and heavy water used by operating CANDU power plants are estimated. The total greenhouse gas emissions from CANDU nuclear plants, per unit of electricity ultimately produced, are very small in comparison with emissions from most other types of power plants. (author)

CANDU reactors and greenhouse gas emissions

International Nuclear Information System (INIS)

Andseta, S.; Thompson, M.J.; Jarrell, J.P.; Pendergast, D.R.

1998-01-01

This paper was originally presented at the 11th Pacific Basin Nuclear Conference, Banff, Alberta, Canada, May 3-7, 1998. It has been updated to include additional lifecycle data on chemical releases from ore treatment and CANDU fuel fabrication. It is sometimes stated that nuclear power plants can supply electricity with zero emissions of greenhouse gases. In fact, consideration of the entire fuel cycle indicates that some greenhouse gases are generated during their construction and decommissioning and by the preparation of fuel and other materials required for their operation. This follows from the use of fossil fuels in the preparation of materials and during the construction and decommissioning of the plants. This paper reviews life cycle studies of several different kinds of power plants. Greenhouse gases generated by fossil fuels during the preparation of fuel and heavy water used by operating CANDU power plants are estimated. The total greenhouse gas emissions from CANDU nuclear plants, per unit of electricity ultimately produced, are very small in comparison with emissions from most other types of power plants. (author)

Voluntary reporting of greenhouse gases 1997

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-05-01

The Voluntary Reporting of Greenhouse Gases Program, required by Section 1605(b) of the Energy Policy Act of 1992, records the results of voluntary measures to reduce, avoid, or sequester greenhouse gas emissions. In 1998, 156 US companies and other organizations reported to the Energy information Administration that, during 1997, they had achieved greenhouse gas emission reductions and carbon sequestration equivalent to 166 million tons of carbon dioxide, or about 2.5% of total US emissions for the year. For the 1,229 emission reduction projects reported, reductions usually were measured by comparing an estimate of actual emissions with an estimate of what emissions would have been had the project not been implemented.

Pilot Greenhouse

CERN Multimedia

1983-01-01

This pilot greenhouse was built in collaboration with the "Association des Maraichers" of Geneva in the frame of the study for making use of the heat rejected as warm water by CERN accelerators and experiments. Among other improvements, more automated and precise regulation systems for heating and ventilation were developed. See also 8305598X.

Study on a groundwater source heat pump cooling system in solar greenhouse

Energy Technology Data Exchange (ETDEWEB)

Chai, Lilong; Ma, Chengwei [China Agricultural Univ., Beijing (China). Coll. of Water Conservancy and Civil Engineering. Dept. of Agricultural Structure and Bio-environmental Engineering], E-mail: macwbs@cau.edu.cn

2008-07-01

This study aims at exploiting the potential of ground source heat pump (GSHP) technology in cooling agricultural greenhouse, and advocating the use of renewable and clean energy in agriculture. GSHP has the multi-function of heating, cooling and dehumidifying, which is one of the fastest growing technologies of renewable energy air conditioning in recent years. The authors carried out experiment on the ground source heat pump system in cooling greenhouse in Beijing region during the summertime of 2007, and conducted analysis on the energy efficiency of the system by using coefficient of performance (COP). According to the data collected during Aug.13-18th, 2007, the coefficient of performance of GSHP system (COP{sub sys}) has reached 3.15 on average during the test. (author)

Greenhouse intelligent control system based on microcontroller

Science.gov (United States)

Zhang, Congwei

2018-04-01

As one of the hallmarks of agricultural modernization, intelligent greenhouse has the advantages of high yield, excellent quality, no pollution and continuous planting. Taking AT89S52 microcontroller as the main controller, the greenhouse intelligent control system uses soil moisture sensor, temperature and humidity sensors, light intensity sensor and CO2 concentration sensor to collect measurements and display them on the 12864 LCD screen real-time. Meantime, climate parameter values can be manually set online. The collected measured values are compared with the set standard values, and then the lighting, ventilation fans, warming lamps, water pumps and other facilities automatically start to adjust the climate such as light intensity, CO2 concentration, temperature, air humidity and soil moisture of the greenhouse parameter. So, the state of the environment in the greenhouse Stabilizes and the crop grows in a suitable environment.

Global greenhouse and energy situation and outlook

International Nuclear Information System (INIS)

Allen, R.W.; Clively, S.R.; Tilley, J.W.

1990-01-01

Fossil fuels provide the basis for world energy usage and, in the absence of fundamental policy changes, are expected to continue to do so for the next few decades. However, the prospect of global warming due to the greenhouse effect will have profound implications for the use of energy. This paper outlines the current situation and trends in world energy use, with a focus on energy requirements by region and fuel. Implications for greenhouse gas emissions and greenhouse policy challenges are also discussed. 8 refs., 1 tab., 2 figs

Accounting for Greenhouse Gas Emissions from Reservoirs

Science.gov (United States)

Nearly three decades of research has demonstrated that the impoundment of rivers and the flooding of terrestrial ecosystems behind dams can increase rates of greenhouse gas emission, particularly methane. The 2006 IPCC Guidelines for National Greenhouse Gas Inventories includes ...

Experimental measurements of the solubility of technetium under near-field conditions

International Nuclear Information System (INIS)

Pilkington, N.J.; Wilkins, J.D.

1988-05-01

The solubility of technetium in contact with hydrated technetium dioxide under near-field conditions has been measured experimentally. The values obtained were changed little by a change in pH or in the filtration method used. The presence of organic degradation products increased slightly the solution concentration of technetium. (author)

NF ISO 14064-1 Greenhouse gases. Part 1: specifications and guidance at the organization level for quantification and reporting of greenhouse gas emissions and removals

International Nuclear Information System (INIS)

2005-01-01

This document describes methodology for quantification, monitoring of greenhouse gas as well as for drafting of inventory report for organisms. Thus it suggests a method for inventory declarations for organism greenhouse gas and provides support for the monitoring and the management of their emission. It provides the terms and definitions, the principles, the greenhouse gases inventory design, development and components, the greenhouse inventory quality management, the reporting of greenhouse gases and the organization role in verification activities. (A.L.B.)

Experimental study of a novel capacity control algorithm for a multi-evaporator air conditioning system

International Nuclear Information System (INIS)

Xu Xiangguo; Pan Yan; Deng Shiming; Xia Liang; Chan Mingyin

2013-01-01

The use of a multi-evaporator air conditioning (MEAC) system is advantageous in terms of installation convenience, high design flexibility, being easy to maintain and commission, better indoor thermal comfort control and higher energy efficiency. While MEAC units worth billions of dollars are sold worldwide, the detailed accounts on compressor capacity control and refrigeration flow distribution amongst evaporators remain unavailable in public domain, mainly due to commercial confidentiality. Limited control algorithms for MEAC systems have been developed based on system simulation, and no experimental-based capacity controller developments and their controllability tests may be identified in open literature. In the study reported in this paper, a novel capacity control algorithm, which imitated On–Off control of a single evaporator air conditioning (A/C) system in each indoor unit of a MEAC system by using variable speed compressor and electronic expansion valves (EEVs), was developed. Controllability tests under various settings for experimentally validating the novel capacity control algorithm were carried out and the control algorithm was further improved based on the experimental results. - Highlights: ► A capacity control algorithm for a multi-evaporator air conditioning system was developed. ► Experimental controllability tests under various settings were carried out. ► The control algorithm was further improved based on the experimental results.

The greenhouse challenge

International Nuclear Information System (INIS)

Harrington, Ph.

1999-01-01

At Kyoto, Australia was successful in gaining acceptance for a differentiated response to climate change which takes account of our special circumstances and allows for an 8% rise in emissions above 1990 levels by 2008 - 2012. This outcome is both environmentally effective but also responsible from the perspective of Australia's economic and trade interests. While our target is achievable it will require significant efforts on the part of industry, all levels of government and the wider community to move towards best practice in managing our greenhouse gas emissions. At the same time, it will provide an incentive for industry and businesses to further improve their efficiency and perhaps even to capture new opportunities that may present themselves. An outline of the National Greenhouse Strategy is given and some of the many implications for the minerals and energy sector are discussed

Analysis of politics about greenhouse effect

International Nuclear Information System (INIS)

Chetouani, L.; Tournier, M.

1992-01-01

This report deals with the greenhouse effect which brings about increasing temperatures. It is based upon documents such as interviews, conferences, political speeches, newspaper articles and so on. After the problem of the greenhouse effect has been exposed, a lexicometric study is carried out. The analysis of all the texts that have been studied finally leads to semiologic interpretations. (TEC). 2 tabs

Seasonal variation of heat consumption in greenhouses

DEFF Research Database (Denmark)

Nielsen, O.F.; Amsen, M.G.; Strøm, J.S.

The concept of dynamic variation is introduced as a method to visualize the dynamic fluctuations of heat consumption and thermal climate in greenhouses. The feasibility of the concept is illustrated by describing effects of different greenhouse designs. Engineering data on design heat consumption...

The greenhouse effect - little strokes fell great oaks

International Nuclear Information System (INIS)

Kanestroem, Ingolf

2003-01-01

It is a common assumption that carbon dioxide and other greenhouse gases constitute only a very small fraction of the atmosphere and thus cannot be as important as the climate researchers maintain. However, the adage of the title is appropriate for the impact of the greenhouse gases on the atmosphere. During the last 25 years, the global temperature has risen 0,5 o C, and during the last century by 0,75 o C. Thus according to the UN Climate Panel, there is evidence of a noticeable anthropogenic impact on the global climate. The article discusses the concept of greenhouse effect, the composition of the atmosphere, greenhouse gases and their importance, emission of carbon dioxide and natural climate changes

Detection of greenhouse-gas-induced climatic change

International Nuclear Information System (INIS)

Wigley, T.M.L.; Jones, P.D.

1992-01-01

The aims of the US Department of Energy's Carbon Dioxide Research Program are to improve assessments of greenhouse-gas-induced climatic change and to define and reduce uncertainties through selected research. This project will address: The regional and seasonal details of the expected climatic changes; how rapidly will these changes occur; how and when will the climatic effects of CO 2 and other greenhouse gases be first detected; and the relationships between greenhouse-gas-induced climatic change and changes caused by other external and internal factors. The present project addresses all of these questions. Many of the diverse facets of greenhouse-gas-related climate research can be grouped under three interlinked subject areas: modeling, first detection and supporting data. This project will include the analysis of climate forcing factors, the development and refinement of transient response climate models, and the use of instrumental data in validating General Circulation Models (GCMs)

Multiagency Initiative to Provide Greenhouse Gas Information

Science.gov (United States)

Boland, Stacey W.; Duren, Riley M.

2009-11-01

Global Greenhouse Gas Information System Workshop; Albuquerque, New Mexico, 20-22 May 2009; The second Greenhouse Gas Information System (GHGIS) workshop brought together 74 representatives from 28 organizations including U.S. government agencies, national laboratories, and members of the academic community to address issues related to the understanding, operational monitoring, and tracking of greenhouse gas emissions and carbon offsets. The workshop was held at Sandia National Laboratories and organized by an interagency collaboration among NASA centers, Department of Energy laboratories, and the U.S. National Oceanic and Atmospheric Administration. It was motivated by the perceived need for an integrated interagency, community-wide initiative to provide information about greenhouse gas sources and sinks at policy-relevant temporal and spatial scales. Such an initiative could significantly enhance the ability of national and regional governments, industry, and private citizens to implement and evaluate effective climate change mitigation policies.

A control method for agricultural greenhouses heating based on computational fluid dynamics and energy prediction model

International Nuclear Information System (INIS)

Chen, Jiaoliao; Xu, Fang; Tan, Dapeng; Shen, Zheng; Zhang, Libin; Ai, Qinglin

2015-01-01

Highlights: • A novel control method for the heating greenhouse with SWSHPS is proposed. • CFD is employed to predict the priorities of FCU loops for thermal performance. • EPM is act as an on-line tool to predict the total energy demand of greenhouse. • The CFD–EPM-based method can save energy and improve control accuracy. • The energy savings potential is between 8.7% and 15.1%. - Abstract: As energy heating is one of the main production costs, many efforts have been made to reduce the energy consumption of agricultural greenhouses. Herein, a novel control method of greenhouse heating using computational fluid dynamics (CFD) and energy prediction model (EPM) is proposed for energy savings and system performance. Based on the low-Reynolds number k–ε turbulence principle, a CFD model of heating greenhouse is developed, applying the discrete ordinates model for the radiative heat transfers and porous medium approach for plants considering plants sensible and latent heat exchanges. The CFD simulations have been validated, and used to analyze the greenhouse thermal performance and the priority of fan coil units (FCU) loops under the various heating conditions. According to the heating efficiency and temperature uniformity, the priorities of each FCU loop can be predicted to generate a database with priorities for control system. EPM is built up based on the thermal balance, and used to predict and optimize the energy demand of the greenhouse online. Combined with the priorities of FCU loops from CFD simulations offline, we have developed the CFD–EPM-based heating control system of greenhouse with surface water source heat pumps system (SWSHPS). Compared with conventional multi-zone independent control (CMIC) method, the energy savings potential is between 8.7% and 15.1%, and the control temperature deviation is decreased to between 0.1 °C and 0.6 °C in the investigated greenhouse. These results show the CFD–EPM-based method can improve system

Greenhouse Gases Concentrations in the Atmosphere Along ...

African Journals Online (AJOL)

This study investigated effect of vehicular emission on greenhouse gases concentrations along selected roads of different traffic densities in Abeokuta, Ogun State, Nigeria. Nine roads comprised highway, commercial and residential were selected. Greenhouse Gases (GHGs) were determined from both sides of the roads by ...

Postnatal development of the hippocampal dentate gyrus under normal and experimental conditions

International Nuclear Information System (INIS)

Altman, J.; Bayer, S.

Studies on postnatal maturation of the dentate gyrus are reviewed. Some topics discussed are: normal development of the dentate gyrus, cytogenesis, morphogenesis, synaptogenesis, gleogenesis, myelogenesis, development of the gyrus under experimental conditions, and effects of x radiation on cytogenesis and morphogenesis

Bibliography of greenhouse-gas reduction strategies

Energy Technology Data Exchange (ETDEWEB)

Tompkins, M.M.; Mintz, M.M.

1995-03-01

A bibliography of greenhouse-gas reduction strategies has been compiled to assist the Climate change Action Plan Task Force in their consideration of strategies to reduce greenhouse-gas emissions from personal motor vehicles. The document contains a summary of the literature, including it major directions and implications; and annotated listing of 32 recent pertinent documents; and a listing of a larger group of related reports.

Building-integrated rooftop greenhouses: An energy and environmental assessment in the mediterranean context

International Nuclear Information System (INIS)

Nadal, Ana; Llorach-Massana, Pere; Cuerva, Eva; López-Capel, Elisa; Montero, Juan Ignacio; Josa, Alejandro

2017-01-01

Highlights: • iRTG incorporates urban agriculture into and improves energy efficiency in buildings. • iRTG concept recycles low-grade, waste thermal energy for growing vegetables. • iRTG is an adaptable concept to promotes food security through urban agriculture. • Indoor building climate affects iRTG more than outdoor climatic conditions. • iRTG achieved annual CO_2 and cost savings of 113.8 kg CO_2 (eq)/m"2/yr and 19.63 €/m"2/yr. - Abstract: A sustainable and secure food supply within a low-carbon and resilient infrastructure is encapsulated in several of The United Nations’ 17 sustainable development goals. The integration of urban agriculture in buildings can offer improved efficiencies; in recognition of this, the first south European example of a fully integrated rooftop greenhouse (iRTG) was designed and incorporated into the ICTA-ICP building by the Autonomous University of Barcelona. This design seeks to interchange heat, CO_2 and rainwater between the building and its rooftop greenhouse. Average air temperatures for 2015 in the iRTG were 16.5 °C (winter) and 25.79 °C (summer), making the iRTG an ideal growing environment. Using detailed thermophysical fabric properties, 2015 site-specific weather data, exact control strategies and dynamic soil temperatures, the iRTG was modelled in EnergyPlus to assess the performance of an equivalent ‘freestanding’ greenhouse. The validated result shows that the thermal interchange between the iRTG and the ICTA-ICP building has considerable moderating effects on the iRTG’s indoor climate; since average hourly temperatures in an equivalent freestanding greenhouse would have been 4.1 °C colder in winter and 4.4 °C warmer in summer under the 2015 climatic conditions. The simulation results demonstrate that the iRTG case study recycled 43.78 MWh of thermal energy (or 341.93 kWh/m"2/yr) from the main building in 2015. Assuming 100% energy conversion efficiency, compared to freestanding greenhouses

Monitoring and Control of Agriculture Parameters in a Greenhouse through Internet

Directory of Open Access Journals (Sweden)

Abhfeeth K. A.

2013-03-01

Full Text Available Greenhouse technology is the technique of providing favorable environment condition to the plants. It is rather used to protect the plants from the adverse climatic conditions such as wind, cold, precipitation, excessive radiation, extreme temperature, insects and disease. It is also of vital importance to create an ideal micro climate around the plants. It requires intensive sensing of the climate conditions at ground level and rapid communication of data to the central repository. Internet is an emerging field that can be used to monitor and control the agriculture parameters in order to make intelligent automated agriculture system. The system basically comprises of host computer having LabView software and internet connection, ZigBee wireless modules for transmitting and receiving the data signals and PIC microcontroller for calculating the agriculture parameters from the sensor voltage and to control the relays according to the control signals send by the user. PIC microcontroller converts the sensor output into serial data and passes it to the ZigBee module. The ZigBee modules are used to transmit the data from the greenhouse to the host computer. The data from sensing node is amplified and fed to ADC of the PIC microcontroller, this is then connected to the ZigBee module, which transmits the data and at the host end, another ZigBee module reads the data and displays on to the host computer via LabView. By using the LabView web publishing tool this data is published in the internet and secured by using username and password. The website is created by using PHP codes and simulated using WAMP server 2.2.The user can monitor and control the greenhouse parameters by logged into the NITT website with proper username and password. The logged user can view the same LabView window as the host with same functionality. The register facility is also available in the website for the new users.

Photovoltaic and Hydrogen Plant Integrated with a Gas Heat Pump for Greenhouse Heating: A Mathematical Study

Directory of Open Access Journals (Sweden)

Alexandros Sotirios Anifantis

2018-02-01

Full Text Available Nowadays, the traditional energy sources used for greenhouse heating are fossil fuels such as LPG, diesel and natural gas. The global energy demand will continue to grow and alternative technologies need to be developed in order to improve the sustainability of crop production in protected environments. Innovative solutions are represented by renewable energy plants such as photovoltaic, wind and geothermal integrated systems, however, these technologies need to be connected to the power grid in order to store the energy produced. On agricultural land, power grids are not widespread and stand-alone renewable energy systems should be investigated especially for greenhouse applications. The aim of this research is to analyze, by means of a mathematical model, the energy efficiency of a photovoltaic (8.2 kW, hydrogen (2.5 kW and ground source gas heat pump (2.2 kW integrated in a stand-alone system used for heating an experimental greenhouse tunnel (48 m2 during the winter season. A yearlong energy performance analysis was conducted for three different types of greenhouse cover materials, a single layer polyethylene film, an air inflated-double layer polyethylene film, and a double acrylic or polycarbonate. The results of one year showed that the integrated system had a total energy efficiency of 14.6%. Starting from the electric energy supplied by the photovoltaic array, the total efficiency of the hydrogen and ground source gas heat pump system was 112% if the coefficient of the performance of the heat pump is equal to 5. The heating system increased the greenhouse air temperatures by 3–9 °C with respect to the external air temperatures, depending on the greenhouse cover material used.

Probabilistic risk assessment of nitrate groundwater contamination from greenhouses in Albenga plain (Liguria, Italy) using lysimeters.

Science.gov (United States)

Paladino, Ombretta; Seyedsalehi, Mahdi; Massabò, Marco

2018-04-05

The use of fertilizers in greenhouse-grown crops can pose a threat to groundwater quality and, consequently, to human beings and subterranean ecosystem, where intensive farming produces pollutants leaching. Albenga plain (Liguria, Italy) is an alluvial area of about 45km 2 historically devoted to farming. Recently the crops have evolved to greenhouses horticulture and floriculture production. In the area high levels of nitrates in groundwater have been detected. Lysimeters with three types of reconstituted soils (loamy sand, sandy clay loam and sandy loam) collected from different areas of Albenga plain were used in this study to evaluate the leaching loss of nitrate (NO 3 - ) over a period of 12weeks. Leaf lettuce (Lactuca sativa L.) was selected as a representative green-grown crop. Each of the soil samples was treated with a slow release fertilizer, simulating the real fertilizing strategy of the tillage. In order to estimate the potential risk for aquifers as well as for organisms exposed via pore water, nitrate concentrations in groundwater were evaluated by applying a simplified attenuation model to the experimental data. Results were refined and extended from comparison of single effects and exposure values (Tier I level) up to the evaluation of probabilistic distributions of exposure and related effects (Tier II, III IV levels). HHRA suggested HI >1 and about 20% probability of exceeding RfD for all the greenhouses, regardless of the soil. ERA suggested HQ>100 for all the greenhouses; 93% probability of PNEC exceedance for greenhouses containing sand clay loam. The probability of exceeding LC50 for 5% of the species was about 40% and the probability corresponding to DBQ of DEC/EC50>0.001 was >90% for all the greenhouses. The significantly high risk, related to the detected nitrate leaching loss, can be attributed to excessive and inappropriate fertigation strategies. Copyright © 2018 Elsevier B.V. All rights reserved.

The isolating effect of greenhouses on arthropod pests [and its significance for integrated pest management] : a case-study on Clepsis spectrana (Lepidoptera: Tortricidae)

NARCIS (Netherlands)

Bos, van den J.

1983-01-01

Chapter 1: the environmental conditions in greenhouses differ in many respects from those in the open field. Both the climate and the crops are different. A free exchange between the fauna of the greenhouses and the open air is hampered by the glass walls and roofs. The isolating effect of

Natural ventilation of large multi-span greenhouses

NARCIS (Netherlands)

Jong, de T.

1990-01-01

In this thesis the ventilation of large multi-span greenhouses caused by wind and temperature effects is studied. Quantification of the ventilation is important to improve the control of the greenhouse climate.

Knowledge of the flow characteristics of the one-side-mounted windows of

Off-season cultivation of capsicums in a solar greenhouse

Energy Technology Data Exchange (ETDEWEB)

Ghosal, M.K.; Tiwari, G.N. [Indian Inst. of Technology, New Delhi (India). Centre for Energy Studies

2001-10-01

The use of solar energy for growing capsicums in pots and in the ground has been studied both under a controlled environment in a solar greenhouse (IIT model) and in an open field during August 2000 to March 2001. Cooling arrangements (natural, forced convection, shading, evaporative cooling) and heating methods (ground air collector, movable insulation during the night) have been employed during the pre-winter and winter periods respectively to maintain the protected environment in the greenhouse. The effects of a north brick wall and the use of movable insulation during the night in the winter months to reduce heat loss from the greenhouse have been incorporated to study the efficacy of the greenhouse. The average height, weight and yield per plant of the greenhouse crop were higher than those of the open field. (author)

Greenhouse effect and climate

International Nuclear Information System (INIS)

Flohn, H.

1987-01-01

Model calculations with different marginal conditions and different physical processes do, on the basis of realistic assumptions, result in a temperature rise of 3 ± 1.5degC at doubling carbon dioxide concentrations. Temperatures are increasing even more due to the presence of trace gases contributing to the greenhouse effect. They are assumed to be having a share of 100% in the carbon dioxide effect (additive) in 30-40 years from now. According to the model calculations the CO 2 increase from about 280 ppm around 1850 to 345 ppm (1985) is equal to a globally averaged temperature rise of 0.5-0.7degC. As the data obtained before 1900 were incomplete and little representative climatic analyses cannot be considered to have been effective but after that time. However, considering the additional influence of other climatic effects such as vulcanism the temperature rise satisfactorily corresponds to the values obtained since 1900. (orig./HP) [de

Politics in the greenhouse

International Nuclear Information System (INIS)

Oberthuer, S.

1993-01-01

Chapter 1 gives an introduction into the problems surrounding the man-made greenhouse effect, the emphasis being on those features that were significant for the course for the international talks. Chapter 2 describes the course of the talks, giving particular attention to the standpoints of the different protagonists. Further the outcome of the talks is presented. Factors that exerted on influence on the standpoints of the protagonists and on the course of the climate talks are examined in Chapter 3 with special consideration to the interests of the individual protagonists and the international constellation of interests, the values supported by the protagonists and the institutional conditions bearing on the course of the talks. Chapter 4 attempts to explain the process of coming to terms about the international climate convention and the results of this process. This is followed in Chapter 5 by a discussion of the room for manoeuvre and possible tendencies of development of the international alliance for climate protection created by the convention. (HSCH) [de

The greenhouse effect: A new source of energy

International Nuclear Information System (INIS)

Meunier, Francis

2007-01-01

Climate change induced by global warming is a result of an excess of energy at the earth's surface due to the greenhouse effect. But a new energy management can reverse the situation taking advantage of the greenhouse effect to produce renewable energy. In fact, both the renewable energy and the energy consumed which are not dissipated into heat are subtracted from the excess of energy produced by the greenhouse effect and contribute to mitigate climate change. This opens perspectives to harness the greenhouse effect [F. Meunier, Domestiquer l'effet de serre, Dunod, 2005]. Should all the primary energy be renewable energy and should part of the energy production not dissipated into heat, the present earth's energy imbalance should be beneficial and should serve to produce renewable energy

Experimental and Theoretical Determination of Heavy Oil Viscosity Under Reservoir Conditions; ANNUAL

International Nuclear Information System (INIS)

Gabitto, Jorge; Barrufet, Maria

2002-01-01

The main objective of this research was to propose a simple procedure to predict heavy oil viscosity at reservoir conditions as a function of easily determined physical properties. This procedure will avoid costly experimental testing and reduce uncertainty in designing thermal recovery processes

Anti-tumorigenic activity of five culinary and medicinal herbs grown under greenhouse conditions and their combination effects.

Science.gov (United States)

Yi, Weiguang; Wetzstein, Hazel Y

2011-08-15

Herbs and spices have been used as food preservatives, flavorings, and in traditional medicines for thousands of years. More and more scientific evidence supports the medicinal properties of culinary herbs. Colon cancer is the third leading cause of cancer death in the USA, and the fourth most common form of cancer worldwide. The objectives of this study were to evaluate the antitumor activity of five selected herbs grown under greenhouse conditions, and to study the potential synergistic effects among different herbal extract combinations. Thyme, rosemary, sage, spearmint, and peppermint extracts significantly inhibited SW-480 colon cancer cell growth, with sage extracts exhibiting the highest bioactivity, with 50% inhibition at 35.9 µg mL⁻¹, which was equivalent to 93.9 µg dried leaves mL⁻¹ of culture medium. Some mixtures of different herbal extracts had combination effects on cancer cell growth. The inhibitory effects of peppermint + sage combinations at a 1:1 ratio were significantly higher than rosemary + sage combinations at 1:1 ratio, although peppermint extracts showed lower inhibition than rosemary extracts. Extracts from herb species (thyme, rosemary, sage, spearmint and peppermint) can significantly inhibit the growth of human colon cancer cells. Mixtures of herb extracts can have combination effects on cancer cell growth. The study suggests that these five herbs may have potential health benefits to suppress colon cancer. Copyright © 2011 Society of Chemical Industry.

Energy and the greenhouse effect. Answers to 60 questions

International Nuclear Information System (INIS)

Visser, H.; De Wolff, J.J.; Folkert, R.J.M.; Hoekstra, J.; Ruijgrok, W.; Stortelder, B.J.M.; Vosbeek, M.E.J.P.; Ruiter, J.P.

1997-11-01

The aim of this report is to clarify the complex interaction between the greenhouse effect and the energy sector in the Netherlands, focusing on the future of the energy supply and how changes in policies with respect to energy consumption can influence climatic change. The relation between energy sector and greenhouse effect is dealt with on the basis of 60 questions on the greenhouse effect, emission of greenhouse gases and energy scenarios, and concise answers. Calculations of consequences of future scenarios for the climate are executed by means of the KEMA-developed integrated scenario model for climatic change DIALOOG. 27 refs

The greenhouse and antigreenhouse effects on Titan

Science.gov (United States)

Mckay, Christopher P.; Pollack, James B.; Courtin, Regis

1991-01-01

The parallels between the atmospheric thermal structure of the Saturnian satellite Titan and the hypothesized terrestrial greenhouse effect can serve as bases for the evaluation of competing greenhouse theories. Attention is presently drawn to the similarity between the roles of H2 and CH4 on Titan and CO2 and H2O on earth. Titan also has an antigreenhouse effect due to a high-altitude haze layer which absorbs at solar wavelengths, while remaining transparent in the thermal IR; if this haze layer were removed, the antigreenhouse effect would be greatly reduced, exacerbating the greenhouse effect and raising surface temperature by over 20 K.

Potato (Solanum tuberosum) greenhouse tuber production as an assay for asexual reproduction effects from herbicides

Science.gov (United States)

The present study determined whether young potato plants can be used as an assay to indicate potential effects of pesticides on asexual reproduction. Solanum tuberosum (Russet Burbank) plants were grown from seed pieces in a mineral soil in pots under greenhouse conditions. Plant...

Policy and Environmental Implications of Photovoltaic Systems in Farming in Southeast Spain: Can Greenhouses Reduce the Greenhouse Effect?

Directory of Open Access Journals (Sweden)

Angel Carreño-Ortega

2017-05-01

Full Text Available Solar photovoltaic (PV systems have grown in popularity in the farming sector, primarily because land area and farm structures themselves, such as greenhouses, can be exploited for this purpose, and, moreover, because farms tend to be located in rural areas far from energy production plants. In Spain, despite being a country with enormous potential for this renewable energy source, little is being done to exploit it, and policies of recent years have even restricted its implementation. These factors constitute an obstacle, both for achieving environmental commitments and for socioeconomic development. This study proposes the installation of PV systems on greenhouses in southeast Spain, the location with the highest concentration of greenhouses in Europe. Following a sensitivity analysis, it is estimated that the utilization of this technology in the self-consumption scenario at farm level produces increased profitability for farms, which can range from 0.88% (worst scenario to 52.78% (most favorable scenario. Regarding the Spanish environmental policy, the results obtained demonstrate that the impact of applying this technology mounted on greenhouses would bring the country 38% closer to reaching the 2030 greenhouse gas (GHG target. Furthermore, it would make it possible to nearly achieve the official commitment of 20% renewable energies by 2020. Additionally, it would have considerable effects on the regional socioeconomy, with increases in job creation and contribution to gross domestic product (GDP/R&D (Research and Development, allowing greater profitability in agrifood activities throughout the entire region.

THERMAL CALCULATION FOR THE PRODUCTION OF VEGETABLES GREENHOUSE

Directory of Open Access Journals (Sweden)

Ancuţa JURCO

2013-01-01

Full Text Available This paper presents the calculation regarding thermic transmision through the closing elements made for a greenhouse designed for salat production, pea, spinach and cabbage, D.M. greenhouse type, with medium and large openings (12...30m having a light roof with spatial structure from bars and thin walls made from galvanized steel or aluminium and designed at the Technique University from Cluj-Napoca. The greenhouse opening is 15.90 m, the total lenght is 40.50m and 669.53 sqm surface with 643.95 sqm usable area. After analyzing the thermal calculations for the production of vegetables greenhouse show that the heat losses are insignificant, advantage is given by the light roof with spatial structure from bars and thin walls made from galvanized steel or aluminium.

A review of greenhouse gas research in Canada

International Nuclear Information System (INIS)

Yundt, P.

1995-11-01

Greenhouse gas research programs and projects that relate to the Canadian natural gas industry were presented. Fossil fuel related emissions, primarily methane and carbon dioxide, impact on the atmospheric concentrations of the greenhouse gases. Therefore, strategies to reduce these emissions should impact on the Canadian natural gas industry. A list of 39 projects and 18 research programs of potential interest to the natural gas industry were presented in summary form. The involvement of CANMET (Canada Centre for Mineral and Energy Technology), Environment Canada, and NSERC (Natural Sciences and Engineering Research Council) in doing or sponsoring research projects directed towards greenhouse gas emission reduction was highlighted. Some potential options for member companies of the Canadian natural gas industry, to support climate change and greenhouse gas research, were outlined. 6 refs., 12 tabs

The greenhouse effect: A new source of energy

Energy Technology Data Exchange (ETDEWEB)

Meunier, Francis [CNAM-IFFI (EA 21), 292 rue Saint Martin, 75141 Paris (France)]. E-mail: meunierf@cnam.fr

2007-02-15

Climate change induced by global warming is a result of an excess of energy at the earth's surface due to the greenhouse effect. But a new energy management can reverse the situation taking advantage of the greenhouse effect to produce renewable energy. In fact, both the renewable energy and the energy consumed which are not dissipated into heat are subtracted from the excess of energy produced by the greenhouse effect and contribute to mitigate climate change. This opens perspectives to harness the greenhouse effect [F. Meunier, Domestiquer l'effet de serre, Dunod, 2005]. Should all the primary energy be renewable energy and should part of the energy production not dissipated into heat, the present earth's energy imbalance should be beneficial and should serve to produce renewable energy.

Positive and negative variations in capacitive images for given defects under varying experimental conditions

Science.gov (United States)

Li, Chen; Yin, Xiaokang; Li, Zhen; Li, Wei; Chen, Guoming

2018-04-01

Capacitive imaging (CI) technique is a novel electromagnetic NDE technique. The Quasi-static electromagnetic field from the carefully designed electrode pair will vary when the electrical properties of the sample change, leading to the possibility of imaging. It is observed that for a given specimen, the targeted features appear as different variations in capacitive images under different experimental conditions. In some cases, even opposite variations occur, which brings confusion to indication interpretation. It is thus thought interesting to embark on investigations into the cause and effects of the negative variation phenomenon. In this work, the positive and negative variations were first explained from the measurement sensitivity distribution perspective. This was then followed by a detailed analysis using finite element models in COMSOL. A parametric experimental study on a glass fiber composite plate with artificial defects was then carried out to investigate how the experimental conditions affect the variation.

Energy saving in greenhouses can be obtained by energy balance-controlled screens

Energy Technology Data Exchange (ETDEWEB)

Andersson, N. E. (Univ. of Aarhus, Faculty of Agricultural Sciences, Dept. of Horticulture, Aarslev (Denmark)), e-mail: niels.andersson@agrsci.dk

2011-03-15

The energy screens in two greenhouses, one clad with double acrylic and one with single glass, were controlled by an energy balance model. The parameters in the model were heat transmission coefficients, air temperature in the greenhouse and outdoors, irradiance and a single constant for the solar energy efficiency. The energy consumption, screen movements and daily light integral were compared with a glass greenhouse in which the energy screens were controlled by irradiance. In the greenhouse with light-controlled screens the set point for opening and closing of the screens was 5 Wm-2. The energy-saving screens controlled by the energy balance model opened later and closed earlier than in the greenhouse with light-controlled screens. When using the energy balance model the energy saving was 14% for the glass greenhouse and 41% for the double acrylic greenhouse compared with the glass greenhouse with light-controlled screens. The air temperature was on average similar in the three greenhouses, but when the screens were controlled by energy balance the daily light integral was approximately 10% lower and the number of hours the screens were closed was prolonged with 35% for the glass-covered greenhouse and 25% for the double acrylic-covered greenhouse compared with the greenhouse with light-controlled screens. Energy peaks in connection with operation of the screens were not reduced. During the experiment Begonia elatior, Dendranthema grandiflora (Chrysanthemum), Hedera helix, Helianthus annuus, Gerbera jamesonii and Kalanchoe blossfeldiana were grown in the greenhouses. There was a trend in prolongation of the production time when the plants were grown in the glass greenhouse with energy balance control of the screens. A lower number of flowers or inflorescences were observed for some of the plant species produced in the greenhouses with energy balance-controlled screens

Comparing greenhouse gases for policy purposes

International Nuclear Information System (INIS)

Schmalensee, R.

1993-01-01

In order to derive optimal policies for greenhouse gas emissions control, the discounted marginal damages of emissions from different gases must be compared. The greenhouse warming potential (GWP) index, which is most often used to compare greenhouse gases, is not based on such a damage comparison. This essay presents assumptions under which ratios of gas-specific discounted marginal damages reduce to ratios of discounted marginal contributions to radiative forcing, where the discount rate is the difference between the discount rate relevant to climate-related damages and the rate of growth of marginal climate-related damages over time. If there are important gas-specific costs or benefits not tied to radiative forcing, however, such as direct effects of carbon dioxide on plant growth, there is in general no shortcut around explicit comparison of discounted net marginal damages. 16 refs

Intergenerational modelling of the greenhouse effect

OpenAIRE

Spash, Clive L.

1994-01-01

A major implication of global climate change is that future generations will suffer severe damages while the current generation benefits. In this paper a model is developed to analyze the potential need for mitigating the adverse impacts of the greenhouse effect on efficiency grounds. The model characterises basic transfers, investigate the effect of greenhouse emissions, and analyze exogenous and endogenous uncertainty. The first (or current) generation faces the problem of dividing availabl...

Greenhouse gas emissions in the Netherlands 1990-1996: Updated methodology

NARCIS (Netherlands)

Spakman J; Olivier JGJ; Loon MMJ van; LAE

1997-01-01

This inventory of greenhouse gas emissions in the Netherlands has been prepared according to the IPCC Guidelines and complies with the obligations under the European Union's Greenhouse Gas Monitoring Mechanism and the UN-FCCC for emission reports on greenhouse gases not covered under the Montreal

Greenhouse tomato production with electricity generation by roof-mounted flexible solar panels

Energy Technology Data Exchange (ETDEWEB)

Urena-Sanchez, Raul; Callejon-Ferre, Angel Jesus; Perez-Alonso, Jose; Carreno-Ortega, Angel [University of Almeria, Depto. de Ingenieia Rural, Almeria (Spain)], E-mail: acallejo@ual.es

2012-07-15

The integration of renewable energy sources into greenhouse crop production in southeastern Spain could provide extra income for growers. Wind energy could be captured by small to medium-sized wind turbines, gas could be produced from biomass, and solar energy could be gathered by solar panels. The aim of this study was to examine the effect of flexible solar panels, mounted on top of a greenhouse for electricity production, on yield and fruit quality of tomatoes (Solanum lycopersicum L., cv Daniela). This study was undertaken in a commercial raspa y amagado greenhouse, typical of the Almeria region (Spain). Tomato plantlets were planted at a density of 0.75 plants m{sup -2}. The flexible solar panels were mounted on two parts of the roof in different arrangements (T1 and T2), each blacking out 9.8 % of its surface area. A control area (T0 arrangement) was fitted with no panels. No difference was found in terms of total or marketable production under these three arrangements, although fruit mean mass and maximum diameter of T0 were significantly greater than T1 and T2. Fruit in T0 matured earlier with more intense color compared with those in T1 and T2. However, these differences had no effect on price as the tomatoes produced under three conditions fell into the same commercial class (G class; diameter 67-81 mm). Solar panels covering 9.8 % roof area of the greenhouse did not affect yield and price of tomatoes despite of their negative effect on fruit size and color. (author)

Greenhouse gas emission from Australian coal mining

International Nuclear Information System (INIS)

Williams, D.

1998-01-01

Since 1997, when the Australian Coal Association (ACA) signed a letter of Intent in respect of the governments Greenhouse Challenge Program, it has encouraged its member companies to participate. Earlier this year, the ACA commissioned an independent scoping study on greenhouse gas emissions in the black coal mining industry This was to provide background information, including identification of information gaps and R and D needs, to guide the formulation of a strategy for the mitigation of greenhouse gas emissions associated with the mining, processing and handling of black coals in Australia. A first step in the process of reducing emission levels is an appreciation of the source, quantity and type of emissions om nine sites. It is shown that greenhouse gas emissions on mine sites come from five sources: energy consumption during mining activities, the coal seam gas liberated due to the extraction process i.e. fugitive emissions, oxidation of carbonaceous wastes, land use, and embodied energy. Also listed are indications of the degree of uncertainty associated with each of the estimates

Greenhouse gas balances of biomass energy systems

International Nuclear Information System (INIS)

Marland, G.; Schlamadinger, B.

1996-01-01

A full energy-cycle analysis of greenhouse gas emissions of biomass energy systems requires analysis well beyond the energy sector. For example, production of biomass fuels impacts on the global carbon cycle by altering the amount of carbon stored in the biosphere and often by producing a stream of by-products or co-products which substitute for other energy-intensive products like cement, steel, concrete or, in case of ethanol form corn, animal feed. It is necessary to distinguish between greenhouse gas emissions associated with the energy product as opposed to those associated with other products. Production of biomass fuels also has an opportunity cost because it uses large land areas which could have been used otherwise. Accounting for the greenhouse gas emissions from biomass fuels in an environment of credits and debits creates additional challenges because there are large non-linearities in carbon flows over time. This paper presents some of the technical challenges of comprehensive greenhouse gas accounting and distinguishes between technical and public policy issues. (author). 5 refs, 5 figs

Greenhouse gas balances of biomass energy systems

International Nuclear Information System (INIS)

Marland, G.; Schlamadinger, B.

1994-01-01

A full energy-cycle analysis of greenhouse gas emissions of biomass energy systems requires analysis well beyond the energy sector. For example, production of biomass fuels impacts on the global carbon cycle by altering the amount of carbon stored in the biosphere and often by producing a stream of by-products or co-products which substitute for other energy-intensive products like cement, steel, concrete or, in case of ethanol from corn, animal feed. It is necessary to distinguish between greenhouse gas emissions associated with the energy product as opposed to those associated with other products. Production of biomass fuels also has an opportunity cost because it uses large land areas which could have been used otherwise. Accounting for the greenhouse gas emissions from biomass fuels in an environment of credits and debits creates additional challenges because there are large nonlinearities in the carbon flows over time. This paper presents some of the technical challenges of comprehensive greenhouse gas accounting and distinguishes between technical and public policy issues

GREENHOUSE-GROWN CAPE GOOSEBERRY

African Journals Online (AJOL)

/2006 S 4,00. Printed in Uganda. All rights reserved O2006, African Crop Science Society. SHORT COMMINICATION. EFFECT OF GIBBERRELLIC ACID ON GROWTH AND FRUIT YIELD OF. GREENHOUSE-GROWN CAPE GOOSEBERRY.

Offsets : An innovative approach to reducing greenhouse gases

International Nuclear Information System (INIS)

Steward, B.

1998-01-01

One of the most innovative ways to address climate change is the use of offsets, which refers to actions taken outside of a company's operations, domestically and internationally, to reduce greenhouse gas emissions. This paper is devoted to a discussion of Suncor Energy's action plan for greenhouse gases which include offsets, and to an explanation of the reasons why offsets are fundamental to successful greenhouse gas management. Suncor Energy Inc., has developed a plan with seven elements to meet their target of stabilizing their greenhouse gas emissions at 1990 levels by year 2000. The seven elements include: (1) energy efficiency and process improvements at their oil sands facility, (2) the development of alternative and renewable sources of energy, such as ethanol blended gasolines and the use of wind turbines to generate electricity, (3) promoting environmental and economic research to develop more advanced oil and gas technology to reduce greenhouse gas emissions, (4) implementing a constructive public policy input in support of sustainable development, (5) educating employees, customers and communities on global climate change, (6) measuring and reporting the company's environmental progress, and (7) pursuing domestic and international offset opportunities such as transfer of technology to developing countries, cogeneration of energy using natural gas, energy efficiency, renewable energy sources, emission reduction purchases and forest conservation. Of these proposed measures, offsets are the critical element which could spell the difference between success and failure in managing greenhouse gas emissions and the difference between economic hardship and economic opportunity

FA1105 BioGreenhouse (2012-04-19 – 2016-04-18) Towards a sustainable and productive EU organic greenhouse horticulture

NARCIS (Netherlands)

Meijer, R.J.M.

2015-01-01

Organic greenhouse horticulture (OGH)(i.e the production in greenhouses or polytunnels)in the EU should
improve its sustainability, production and productivity. Emissions of nutrients and its footprint should be
reduced. Production and productivity are too low to meet the demand of the

FA1105 BioGreenhouse (2012-04-19 – 2016-04-18) Towards a sustainable and productive EU organic greenhouse horticulture

NARCIS (Netherlands)

Meijer, R.J.M.

2015-01-01

Organic greenhouse horticulture (OGH)(i.e the production in greenhouses or polytunnels)in the EU should improve its sustainability, production and productivity. Emissions of nutrients and its footprint should be reduced. Production and productivity are too low to meet the demand of the society. The

State and Territory Greenhouse Gas Emissions 2004

International Nuclear Information System (INIS)

2006-06-01

This document provides an overview of the latest available estimates of greenhouse gas emissions for Australia's States and Territories. Australia's total greenhouse gas emissions in 2004 amounted to 564.7 million tonnes. The State and Territory breakdown was: New South Wales: 158.7 million tonnes (Mt); Queensland: 158.5 Mt; Victoria: 123.0 Mt; Western Australia: 68.5 Mt; South Australia: 27.6 Mt; Northern Territory: 15.6 Mt; Tasmania: 10.7 Mt; ACT: 1.2 Mt. The summary of State and Territory inventories presented in this document reports estimates of greenhouse gas emissions for each State and Territory for the period 1990 to 2004. It is the first time that a complete annual time-series has been reported

Structural analysis of Gossypium hirsutum fibers grown under greenhouse and hydroponic conditions.

Science.gov (United States)

Natalio, Filipe; Tahir, Muhammad Nawaz; Friedrich, Norman; Köck, Margret; Fritz-Popovski, Gerhard; Paris, Oskar; Paschke, Reinhard

2016-06-01

Cotton is the one of the world's most important crops. Like any other crop, cotton growth/development and fiber quality is highly dependent on environmental factors. Increasing global weather instability has been negatively impacting its economy. Cotton is a crop that exerts an intensive pressure over natural resources (land and water) and demands an overuse of pesticides. Thus, the search for alternative cotton culture methods that are pesticide-free (biocotton) and enable customized standard fiber quality should be encouraged. Here we describe a culture of Gossypium hirsutum ("Upland" Cotton) utilizing a greenhouse and hydroponics in which the fibers are morphological similar to conventional cultures and structurally fit into the classical two-phase cellulose I model with 4.19nm crystalline domains surrounded by amorphous regions. These fibers exhibit a single crystalline form of cellulose I-Iß, monoclinic unit cell. Fiber quality bulk analysis shows an improved length, strength, whiteness when compared with soil-based cultures. Finally, we show that our fibers can be spun, used for production of non-woven fabrics and indigo-vat stained demonstrating its potential in industrial and commercial applications. Copyright © 2016 Elsevier Inc. All rights reserved.

An innovation in the teaching of greenhouse effect in chemistry ...

African Journals Online (AJOL)

The teaching of greenhouse effect is difficult and is done in abstraction. This paper suggests a new instrument, called Improvised Greenhouse Effect Apparatus (IGHA) for the teaching of Greenhouse effect. 100 students were randomly selected from the Department of Chemistry, Cross River State College of Education, ...

Coal and the greenhouse effect: strategies for the future

Energy Technology Data Exchange (ETDEWEB)

Sullivan, K M [Australian Coal Association, Sydney, NSW (Australia)

1991-07-01

A number of gases, including carbon dioxide, methane, water vapour, nitrous oxide, ozone and chlorofluorocarbons are transparent to incoming short-wave radiation, but are relatively opaque to outgoing longwave radiation. Variations in the concentration of these gases in the troposphere can alter the thermal balance of the earth's atmosphere. Outgoing terrestrial radiation which would otherwise escape to space, is trapped within the inner layer of the atmosphere, resulting in a potential warming and the greenhouse effect. It is estimated that at present greenhouse gases other than carbon dioxide, contribute about 50% to the greenhouse effect. However, in the future, the contribution made by gases other than CO{sub 2} will be become greater. Greenhouse gases arise from a wide range of sources and their escalating increase is largely related to an increase in the world's population, and the standard of living of many areas as well as changes in lifestyle. The effect of increasing man-made greenhouse gases in the troposphere is unknown, but it is proposed that it may increase temperature and may modify climate, agricultural response and land use. The facts and uncertainties relating to potential greenhouse warming are examined. Man-generated emissions are quantified and their source identified. Coal's contribution worldwide is examined in detail and is shown to be small, being about 10% of man-made greenhouse gases. Strategies for minimising emissions, having maximum potential for reduction, with minimum impact on man are suggested. 16 refs., 1 fig., 3 tabs.

Control of Pathogenicity Root-Knot Nematode (Meloidogyne Javanica by Earthworm Eisenia Feoetida-Based Products in Greenhouse

Directory of Open Access Journals (Sweden)

M. Rostami

2016-06-01

Full Text Available Introduction: Biocontrol of nematode agents in order to decrease the hazardous impacts of chemical pesticide application including problems of public health and environmental pollution is apriority. In this study, solid (Vermicompost and liquid products (Liquid Vermicompost, Vermiwash and Coelomic fluidof the earthworm species Eisenia fetida were tested against root-knot nematode, Meloidogyne javanica in greenhouse conditions. Materials and Methods: In this study, Solid (Vermicompost and Liquid products(Wormtea, Vermiwash, Coelomic fluid erthworms (Eisenia foetida were tested against Meloidogyne javanica and also the effect of Vermicompost was evaluated on Pathogenicity of various nematode initial inoculum in two stage greenhouse conditions. Earthworm-based products (Vermicompost, Wormtea, Vermiwash and Coelomic fluid were added to tomato pots. Various treatments of liquid as well as solid products and their combination were used in the greenhouse trial. The first Stage greenhouse experiment- Tomato seeds grown in 2 kg sterilized soil. In the treatments having Vermicompost, pots incorporated with 200 gr of this compost homogeneously mixed with soil. After plants reached at two leaf stage, to study the effects of liquid products (Wormtea, Vermiwash, and Coelomic fluid they added to the pots (500cc along with the irrigation water every week and after of 4 leaf stage, 5000 nematode eggs and larva inoculated to the tomato host plants. 90 days after nematode inoculation, plant and nematode growth indices separately measured and compared. The experiment conducted based on completely randomized design having four replicates. The second stage greenhouse experiment- Tomato seeds grown in 2 kg sterilized soil. In the treatments, pots incorporated with 200 gr of this compost homogeneously mixed with soil. After of 4 leaf stage, 0,1000,2000,4000 and 10000 nematode eggs and larva inoculated to the tomato host plants. 90 days after nematode inoculation, plant

Policy implications of greenhouse warming: Mitigation, adaptation, and the science base

International Nuclear Information System (INIS)

Anon.

1992-01-01

This book discusses the policy implications of greenhouse warming by examining three major areas: general summary of information about the greenhouse effect leading to a framework for policy; the science basis for the greenhouse effect; mitigation of greenhouse warming. Each section contains 9-13 chapters on specific subjects including the following: overview of greenhouse gases; policy implications; internations considerations; climate records and models; sea levels; temperature rise estimation; energy management at several levels; nonenergy emission reduction; human populations; deforestation. Conclusions are summarized at the end of each section

Mechanisms of Oryza sativa (Poaceae) resistance to Tagosodes orizicolus (Homoptera: Delphacidae) under greenhouse condition in Venezuela.

Science.gov (United States)

González, Alex; Labrín, Natalia; Alvarez, Rosa M; Jayaro, Yorman; Gamboa, Carlos; Reyes, Edicta; Barrientos, Venancio

2012-03-01

Tagosodes orizicolus is one of the main plagues of rice in tropical America causing two types of damages, the direct one, feeding and oviposition effect, and an indirect one, by the transmission of the "Rice hoja blanca virus". During 2006-2007 we carried out research under greenhouse conditions at Fundaci6n Danac, Venezuela, in order to determine the mechanisms of antixenosis, antibiosis and tolerance to T. orizicolus, which could be acting in commercial varieties and advanced lines of the rice genetic breeding programs of INIA and Fundaci6n Danac. The method of free feeding was used for the antixenosis evaluation, whereas the method of forced feeding was used for antibiosis evaluation (effect on survival and oviposition). Additionally, we used the indirect method based on biomass depression to estimate the tolerance. Some of the evaluated traits included: grade of damage, number of insects settling on rice plants, percentage of sogata mortality at the mature state, number of eggs in the leaf midrib and an index of tolerance. The results showed that rice genotypes possess different combinations of resistance mechanisms, as well as different grades of reactions. The susceptible control 'Bluebonnet 50' was consistently susceptible across experiments and the resistant control 'Makalioka' had high antixenosis and high antibiosis based on survival and oviposition. The rest of the genotypes presented lower or higher degrees of antixenosis and antibiosis for survival and oviposition. The genotype 'FD0241-M-17-6-1-1-1-1' was identified with possible tolerance to the direct damage of sogata.

Nuclear power and the greenhouse effect

International Nuclear Information System (INIS)

1989-01-01

Carbon dioxide from fossil fuel combustion accounts for about 40% of the global warming due to the 'greenhouse effect'. Thus national energy policies of the fuels used to generate electricity can have a significant effect on the levels of gas emissions which contribute to the 'greenhouse effect'. The more efficient use of energy is the first way of controlling the increase in gas emissions. The use of natural gas instead of coal or oil would also be beneficial but the reserves of natural gas are limited. The use of nuclear-generated electricity has already reduced the level of global warming by 3% but could have a greater effect in the future. Ways in which the government could reduce 'greenhouse' gas emissions are listed. These include the more extensive use of nuclear power for generating electricity not only for domestic but industrial uses. (U.K.)

Accounting For Greenhouse Gas Emissions From Flooded Lands

Science.gov (United States)

Nearly three decades of research has demonstrated that the inundation of rivers and terrestrial ecosystems behind dams can lead to enhanced rates of greenhouse gas emissions, particularly methane. The 2006 IPCC Guidelines for National Greenhouse Gas Inventories includes a method...

Atmospheric greenhouse effect - simple model; Atmosfaerens drivhuseffekt - enkel modell

Energy Technology Data Exchange (ETDEWEB)

Kanestroem, Ingolf; Henriksen, Thormod

2011-07-01

The article shows a simple model for the atmospheric greenhouse effect based on consideration of both the sun and earth as 'black bodies', so that the physical laws that apply to them, may be used. Furthermore, explained why some gases are greenhouse gases, but other gases in the atmosphere has no greenhouse effect. But first, some important concepts and physical laws encountered in the article, are repeated. (AG)

Experiences on the integration of thin film photovoltaic modules in a Mediterranean greenhouse

Energy Technology Data Exchange (ETDEWEB)

Urena, R.; Perez, J.; Carreno, A.; Callejon, A.J.; Vazquez, F.J. [Almeria Univ., Almeria (Spain). Dept. of Rural Engineering; Perez, M. [Almeria Univ., Almeria (Spain). CIESOL Research Center on Solar Energy

2010-07-01

This paper discussed the use of photovoltaic (PV) thin film modules in solar based energy generation systems in greenhouses in Spain, where feed-in tariffs for renewable energy sources serve to increase the yearly income of such agricultural exploitations. Experiments were performed at the University of Almeria, where a 1000 m{sup 2} pilot installation was built and monitored to analyze the key features of the system design and functionalities in terms of overall electricity injected into the grid as well as crop productivity. The installation involved dividing the greenhouse sections into 2 identical and contiguous sections, where one of the roof sections was equipped with a set of carefully designed thin film PV module strips. Both sections were grown under similar conditions for a period of 6 months. Continuous monitoring of the power injected to the grid showed that such a system is feasible. In terms of greenhouse crop results, this study showed that there is need for further research regarding the impact of changes in optical properties to the roof by the PV strips that reduced the available PV active radiation (PAR light) for crops.

PLASTIC AND GLASS GREENHOUSES DETECTION AND DELINEATION FROM WORLDVIEW-2 SATELLITE IMAGERY

Directory of Open Access Journals (Sweden)

D. Koc-San

2016-06-01

Full Text Available Greenhouse detection using remote sensing technologies is an important research area for yield estimation, sustainable development, urban and rural planning and management. An approach was developed in this study for the detection and delineation of greenhouse areas from high resolution satellite imagery. Initially, the candidate greenhouse patches were detected using supervised classification techniques. For this purpose, Maximum Likelihood (ML, Random Forest (RF, and Support Vector Machines (SVM classification techniques were applied and compared. Then, sieve filter and morphological operations were performed for improving the classification results. Finally, the obtained candidate plastic and glass greenhouse areas were delineated using boundary tracing and Douglas Peucker line simplification algorithms. The proposed approach was implemented in the Kumluca district of Antalya, Turkey utilizing pan-sharpened WorldView-2 satellite imageries. Kumluca is the prominent district of Antalya with greenhouse cultivation and includes both plastic and glass greenhouses intensively. When the greenhouse classification results were analysed, it can be stated that the SVM classification provides most accurate results and RF classification follows this. The SVM classification overall accuracy was obtained as 90.28%. When the greenhouse boundary delineation results were considered, the plastic greenhouses were delineated with 92.11% accuracy, while glass greenhouses were delineated with 80.67% accuracy. The obtained results indicate that, generally plastic and glass greenhouses can be detected and delineated successfully from WorldView-2 satellite imagery.

Examination of the conditions of a broadening of the general tax for polluting activities to the intermediate energy consumptions. Incentive mechanisms for the abatement of greenhouse gas emissions; Examen des conditions d'un elargissement de la TGAP aux consommations intermediaires d'energie. Mecanismes incitatifs a la reduction des emissions de gaz a effet de serre

Energy Technology Data Exchange (ETDEWEB)

Bureau, D

2000-05-15

Among the various existing incentive mechanisms for the abatement of greenhouse gas emissions, like the pollution regulations and the financial help for energy mastery, this document analyzes the conditions of efficiency of the negotiated voluntary agreements and of the tradable emission quotas and their articulation with the fiscality. (J.S.)

Desempenho agronômico de linhas endogâmicas ecombinadas de Capsicum annuum L. em sistema orgânico sob cultivo protegido Agronomic performance of recombinant inbred of Capsicum annuum L. lines cultivated under organic system and greenhouse conditions

Directory of Open Access Journals (Sweden)

Sarah Ola Moreira

2010-08-01

Full Text Available O manejo de plantas em cultivo protegido e a busca de produtos orgânicos pelos consumidores têm sido um desafio para produtores e pesquisadores de hortaliças. Para que essas formas de cultivo proporcionem lucratividade ao produtor e frutos de qualidade para o consumidor, faz-se necessária a busca por genótipos adaptados a esse manejo diferenciado. Neste trabalho, objetivouse avaliar o desempenho de 12 linhas endogâmicas recombinadas de Capsicum annuum L., obtidas do cruzamento entre os acessos UENF 1421 e UENF 1381, em cultivo protegido sob manejo orgânico. O experimento foi instalado em casa de vegetação, na Estação Experimental de Seropédica da PESAGRO-RIO, em blocos casualizados, com quatro repetições. Avaliaram-se o número total de frutos (NTF, peso total de frutos (PTF, peso médio dos frutos (PMF, comprimento dos frutos (CF, diâmetro dos frutos (DF, relação comprimento/diâmetro do fruto (CF/DF e presença de capsaicina (CAPS. Foram estimados os parâmetros genéticos variâncias genotípica, fenotípica e ambiental, coeficientes de determinação genotípico e de variação genética e o índice de variação. Houve diferença altamente significativa para todas as características, exceto para PTF. As linhas produziram elevado número de frutos, leves e de formatos variados. Somente duas linhas não tiveram pungência e quatro segregaram para CAPS. Todas as características tiveram alta variância genotípica e altos coeficientes de determinação genotípicos, mostrando que os resultados são, predominantemente, de origem genética. Os dados permitiram a indicação preliminar das linhas 5 e 8 para o cultivo orgânico em ambiente protegido.Plant management under greenhouse conditions, associated with search for ecological products by consumers, has been a challenge for both farmers and vegetable researchers. Obtaining profit and quality depends on adapted genotypes that can be grown using an adequate management. The aim

Organic-mineral and organic fertilization in the strawberry (Fragaria x Ananasa Duch. crop under greenhouse conditions

Directory of Open Access Journals (Sweden)

Carlos Osvaldo Romero Romano

2012-09-01

Full Text Available A good combination of organic fertilizers and mineral fertilizers may allow a reduction in the use of agrochemicals, to benefit the environment and health of consumers, to obtained crops and safe products with lower content of chemical residues. In this paper, we assess the effect of organic fertilization and organic mineral in the cultivation of strawberries cv. Festival, in a factorial treatment designin 3x23 with 24 treatments in an experimental design in randomized blocks with four replicates under greenhouse conditions in Atlixco, Puebla. The factors and levels of study: chemical fertilization (FQ, three levels of N-P2O5-K2O 0-0-0, 45-20-20 and 90-35-35 kg ha-141 3 con un total de 24 commercial organic nutrient (Activator QFprepared fulvic acid (AF at a concentration of (13.58% with two levels 0 and 450 ml ha-1,growth regulator (RCcommercial vegetable (Biozyme®, whit 78.87% of plant extracts and phytohormones, and 1.86% of microelements at evels of 0 and 20 l ha-1 and vermicompost (V of cattle manure at 50 and 100 g / pot. The experiment was divided into two periods from February to May and June to September 2011. The treatments applications were edafic (FQ and V and foliar (AF and RC in both stages of treatment applications were made at 10, 40 and 60 days after transplantation. The variables analyzed were number of stolons, stolon length, diameter and length fruit, number and weight of fruit per week, period, and the total of the two periods. Two twice a week the number of ripe fruits was counted, the diameter and length fruit and weight was measured. Every eight days after the formation of the first stolons, counted and measured. Statistical analysis was performed using the SAS program. In the period from February-May treatment FQ50-AF1-RC1-V50 showedstatistically different (Tukey, p = 0.05 %. for variables length fruit (2.95 cm, diameter fruit (3.76 cm, weight of fruit perweek (11.31 g and period (135.69 g. In the period from June

Pragmatics in the greenhouse

Energy Technology Data Exchange (ETDEWEB)

Grubb, M.J.; Victor, D.G.; Hope, C.W. (Royal Institute of International Affairs, London (UK))

1991-12-05

Negotiations towards a global framework convention on climate change are hampered by the range of greenhouse gases, sources and sinks. The US government promotes a comprehensive approach to climate change which provides flexibility but faces obstacles arising from the different characteristics of the sources and sinks involved, and uncertainties in attempting to estimate and compare the radiative impacts of different gases. Relying on approximations to enable a comprehensive approach is unrealistic for two reasons: monitoring and revision. The comprehensive approach is a worthwhile goal but is not yet fully practicable. Two lists are suggested - a quantified list for CFCs and CO{sub 2} and a transition list. Frequent renegotiation would be necessary. With this approach an overall goal for controlling the magnitude and rate of change in greenhouse forcing is possible. 12 refs., 1 fig.

Does the Swedish consumer's choice of food influence greenhouse gas emissions?

International Nuclear Information System (INIS)

Wallen, Anna; Brandt, Nils; Wennersten, Ronald

2004-01-01

Consumer's choice of food can influence the environment. In Sweden, in common with many other countries, consumers need to be given information so they can make environmentally informed shopping choices. However, what is the most advantageous dietary choice to lower greenhouse emissions? This study investigates the greenhouse gas emissions associated with food production for food consumed in Sweden annually. Specifically, this study compares greenhouse gas emissions associated with a nutritionally and environmentally sustainable diet with the average consumption of food in Sweden 1999. The study concludes that the change in energy use and greenhouse gas emission associated with this change of diet is negligible. Lowering greenhouse gas emissions by changing food production processes results in more profound changes than teaching consumers to make environmentally correct choices. There is a basic need for a reduction or a replacement of the use of fossil fuels to produce and distribute our food in order to reach any significant reduction in the emission of greenhouse gases. Swedish agricultural policy does not provide ways to reduce greenhouse gas emissions. In Sweden therefore there is an immediate need to design policy instruments with the primary aim of reducing the greenhouse effect

Conditioned responses elicited by experimentally produced cues for smoking.

Science.gov (United States)

Mucha, R F; Pauli, P; Angrilli, A

1998-03-01

Several theories of drug-craving postulate that a signal for drug elicits conditioned responses. However, depending on the theory, a drug cue is said to elicit drug similar, drug compensatory, positive motivational, and negative motivational effects. Since animal data alone cannot tease apart the relative importance of different cue-related processes in the addict, we developed and examined a model of drug cues in the human based on a two-sound, differential conditioning procedure using smoking as the reinforcer. After multiple pairings of a sound with smoking, there was a preference for the smoking cue on a conditioned preference test. The acute effects of smoking (increased heart rate, respiration rate, skin conductance level, skin conductance fluctuations, EEG beta power and trapezius EMG, decreased alpha power) were not affected by the smoking cue, although subjects drew more on their cigarette in the presence of the smoking cue than in the presence of a control cue. Moreover, the cue did not change baseline behaviour except for a possible increase in EEG beta power and an increase in trapezius EMG at about the time when smoking should have occurred. The findings confirm the value of experimental models of drug cues in the human for comparing different cue phenomena in the dependent individual. They indicate that an acquired signal for drug in the human may elicit incentive motivational effects and associated preparatory motor responses in addition to possible conditioned tolerance.

An experimental study of low concentration sludge settling velocity under turbulent condition.

Science.gov (United States)

Guo, Lisha; Zhang, Daijun; Xu, Danyu; Chen, Yuan

2009-05-01

Particle Image Velocimetry (PIV) was used to study the settling of activated sludge flocs under turbulent flow conditions. Experimental results showed that a larger particle diameter led to a higher settling velocity while the higher turbulence intensity led to lower settling velocity. Based on the measurements a mathematical relation has been derived which correlates the settling velocity for individual sludge flocs under turbulent conditions through a modified Vesilind equation. Settling velocity shows a power-type relation to sludge particle diameter and an exponential-type relation with turbulence intensity and sludge concentration.

Nuclear power and the greenhouse effect

International Nuclear Information System (INIS)

Donaldson, D.M.; Tolland, H.G.

1989-05-01

Global levels of the ''Greenhouse'' gases - carbon dioxide, the chlorofluorocarbons (CFCs), methane, nitrous oxide and tropospheric ozone are increasing as a result of man's activities. This increase is widely expected to bring about a rise in global temperature with concomitant environmental impacts. Global warming has been observed over the last century, and the last decade has seen seven of the warmest years on record. There has also been increased variability in the weather (an expected consequence of global warming). However, these possible manifestations of the Greenhouse Effect are within natural variations and proof must await more definitive indications. A brief outline of current views on the Greenhouse Effect is given. This report addresses the energy sector using CO 2 emissions as a measure of its ''Greenhouse'' contribution. This approach understates the energy sector contribution. However, the difference is within the error band. It seems likely that the warming effect of non-energy related emissions will remain the same and there will be more pressure to reduce the emissions from the energy sector. To assess policy options the pattern of future energy demand is estimated. Two scenarios have been adopted to provide alternative frameworks. Both assume low energy growth projections based on increased energy efficiency. The role of nuclear power in reducing carbon dioxide emissions is considered. (author)

Assessment of the impact of the greenhouse gas emission and sink scenarios in Finland on radiative forcing and greenhouse effect

Energy Technology Data Exchange (ETDEWEB)

Savolainen, I; Sinisalo, J; Pipatti, R [Technical Research Centre of Finland, Espoo (Finland)

1997-12-31

The objective of this work is to study greenhouse gas emissions and sinks and their greenhouse impact as a function of time. The greenhouse impact is expressed in terms of global average radiative forcing, which measures the perturbation in the Earth`s radiation budget. Radiative forcing is calculated on the basis of the concentration changes of the greenhouse gases and the radiation absorption properties of the gases. It takes into account the relatively slow changes in the concentrations due to natural removal and transformation processes and also allows a comparison of the impact of various greenhouse gases and their possible control options as a function of time. In addition to the applications mentioned above, the anthropogenic greenhouse gas emission histories of Nordic countries have been estimated, and the radiative forcing caused by them has been calculated with REFUGE. The dynamic impact of aerosol emissions both from the global point of view and in the context of different energy sources (coal, oil and natural gas) have also been studied. In some instances the caused radiative forcing has been examined on a per capita basis. The radiative forcing calculations contain considerable uncertainty due to inaccurately known factors at several stages of the calculation (emission estimation, concentration calculation and radiative forcing calculation). The total uncertainty of the results is typically on the order of +- 40 %, when absolute values are used. If the results are used in a relative way, e.g. to compare the impacts of different scenarios, the final uncertainty is considerably less (typically + 10 %), due to correlations in almost all stages of the calculation process

Assessment of the impact of the greenhouse gas emission and sink scenarios in Finland on radiative forcing and greenhouse effect

Energy Technology Data Exchange (ETDEWEB)

Savolainen, I.; Sinisalo, J.; Pipatti, R. [Technical Research Centre of Finland, Espoo (Finland)

1996-12-31

The objective of this work is to study greenhouse gas emissions and sinks and their greenhouse impact as a function of time. The greenhouse impact is expressed in terms of global average radiative forcing, which measures the perturbation in the Earth`s radiation budget. Radiative forcing is calculated on the basis of the concentration changes of the greenhouse gases and the radiation absorption properties of the gases. It takes into account the relatively slow changes in the concentrations due to natural removal and transformation processes and also allows a comparison of the impact of various greenhouse gases and their possible control options as a function of time. In addition to the applications mentioned above, the anthropogenic greenhouse gas emission histories of Nordic countries have been estimated, and the radiative forcing caused by them has been calculated with REFUGE. The dynamic impact of aerosol emissions both from the global point of view and in the context of different energy sources (coal, oil and natural gas) have also been studied. In some instances the caused radiative forcing has been examined on a per capita basis. The radiative forcing calculations contain considerable uncertainty due to inaccurately known factors at several stages of the calculation (emission estimation, concentration calculation and radiative forcing calculation). The total uncertainty of the results is typically on the order of +- 40 %, when absolute values are used. If the results are used in a relative way, e.g. to compare the impacts of different scenarios, the final uncertainty is considerably less (typically + 10 %), due to correlations in almost all stages of the calculation process

Greenhouse effect economic simulation and public decision

International Nuclear Information System (INIS)

Giraud, P.N.

2002-03-01

As the other countries, engaged in the greenhouse effect fight, the France has to evaluate the greenhouse gases emissions and the corrective actions. Meanwhile the today models are not enough impressive. The economic tools authorize today a better evaluation. The technical working Group, presided by Pierre-Noel Giraud, proposes to use them largely and provides four main recommendations. (A.L.B.)

Greenhouse effect: doubts and unknowns

International Nuclear Information System (INIS)

Tabarelli, D.

1992-01-01

There are few doubts today in the scientific world that atmospheric carbon dioxide traps in heat and therefore contributes to global warming; however, it is yet uncertain as to whether the presence of this gas in the upper atmosphere is the only cause of the greenhouse effect, and the scientific theories defining the effect and its causes present a few obvious and significant gaps. This paper cites the fact that most greenhouse effect models only marginally, if at all, consider the mechanisms governing the formation and absorption of carbon dioxide by the earth's oceans; yet oceanic CO 2 concentration levels are about 60 times greater than those found in the atmosphere, and they depend on complex interactions, in seawater, among such factors as currents, carbon oxygenation, and vegetative activity. Another area of weakness in greenhouse effect modelling stems from the complexity and uncertainty introduced by the fact that, in addition to trapping heat, clouds reflect it, thus giving rise to an opposite cooling effect. In addition, it is pointed out that the current models are limited to predicting global and not regional or local effects

A Hiatus of the Greenhouse Effect

OpenAIRE

Jinjie Song; Yuan Wang; Jianping Tang

2016-01-01

The rate at which the global average surface temperature is increasing has slowed down since the end of the last century. This study investigates whether this warming hiatus results from a change in the well-known greenhouse effect. Using long-term, reliable, and consistent observational data from the Earth?s surface and the top of the atmosphere (TOA), two monthly gridded atmospheric and surface greenhouse effect parameters (G a and G s) are estimated to represent the radiative warming effec...

Effect of greenhouse micro-climate on the selected summer vegetables

International Nuclear Information System (INIS)

Sethi, V.P.; Lal, T.; Gupta, Y.P.; Hans, V.S.

2003-01-01

The study deals with creating suitable environment for the germination and subsequent growth of plants in the greenhouse of size 7 m x 3 m x 2 m for raising early summer vegetable nursery. It was observed that the average air temperature inside the greenhouse was 10–12°C higher than the ambient air temperature. Inside average soil temperature was also 5–7°C higher than the corresponding temperature outside the greenhouse. Greenhouse night micro-climate was modified by covering its roof with a polyester sheet to cut down the effect of night sky radiation thereby raising the inside minimum temperature. The effect of elevated temperature was monitored on the germination and subsequent growth of “muskmelon” seedlings up to two true leaf stage. It was observed that the germination of seeds, sown inside the greenhouse occurred one week earlier as compared to the seeds sown in the open field. The rate of growth of the seedlings inside the greenhouse took only three weeks to attain two-leaf stage, whereas seedlings sown in the open field took five weeks to reach up to two-leaf stage. Thus, there was a clear saving of 15 days in raising the nursery under the greenhouse. (author)

Wind conditions in urban layout - Numerical and experimental research

Science.gov (United States)

Poćwierz, Marta; Zielonko-Jung, Katarzyna

2018-01-01

This paper presents research which compares the numerical and the experimental results for different cases of airflow around a few urban layouts. The study is concerned mostly with the analysis of parameters, such as pressure and velocity fields, which are essential in the building industry. Numerical simulations have been performed by the commercial software Fluent, with the use of a few different turbulence models, including popular k-ɛ, k-ɛ realizable or k-ω. A particular attention has been paid to accurate description of the conditions on the inlet and the selection of suitable computing grid. The pressure measurement near buildings and oil visualization were undertaken and described accordingly.

Greenhouse effect: analysis, incertitudes, consequences

International Nuclear Information System (INIS)

Perrier, A.

1991-01-01

A general presentation of climatic changes due to greenhouse effect with their consequences is analysed. After a schematic description of this effect a simplified atmospheric model (box model) is proposed. This model integrates the main feedback effects and quantifies them. The effects of astronomic and atmospheric factors on climatic changes are analyzed and compared with classical paleoclimatic results. This study shows the need of good global modelization to evaluate long term quantification of climatic greenhouse effects according to the main time lag of the several biospheric boxes. An overview of biologic and agronomic consequences is given to promote new research subjects and to orientate protecting and conservative biospheric actions [fr

Natural gas based infrared heating i greenhouses. Phase II. System optimization; Naturgasbaserad infravaerme i vaexthus. Fas II. Systemoptimering

Energy Technology Data Exchange (ETDEWEB)

Naeslund, Mikael [Lund Inst. of Tech. (Sweden). Dept. of Heat and Power Engineering; Schuessler, Hartmut K. [Swedish Univ. of Agricultural Sciences, Alnarp (Sweden); Ljungberg, Sven-Aake [Hoegskolan i Gaevle (Sweden). Avdelningen byggnadskvalitet

2004-01-01

The energy use is high in greenhouses and the cost of energy is a substantial part of the plant production cost. Infrared heating (IR) has been shown to decrease the heating demand in industrial facilities and similar buildings. IR was studied with the same purpose for greenhouses. Special emphasis has also been put on the plant growth and quality. Temperature measurements showed a slightly more than 10% decrease in net heating demand compared to the reference houses in the same facility. A saving of 10-15% should be possible with some improvements. Temperature measurements at a few selected points in the infrared heated greenhouse and thermography showed differences. Repeated thermography during similar radiation conditions showed that the production tables in the infrared heated house had differences in radiation temperature and distribution caused by inhomogenous radiation from the radiating tubes. These radiation variations cause differences in in conditions and growth for cuttings and plants in later stage of growth. The thermography study also indicate that the humidity is an important factor for redistributing the radiation and ensure an optimal micro climate when infrared heaters are used in greenhouses. These differences can be reduced if the greenhouse floor layout allows radiating tubes to be located in order to make adjacent radiation fields partly overlapping. Also, burner input, excess air ratio and radiation tube and reflector design are influential for the performance. Good design criteria are discussed. Careful studies of the root development also showed differences caused by the plant location with regard to the heating tubes. The differences were reduced after reporting and further growth. One cultivation even turned out to be more compact and thus of higher quality when infrared heating was used.

Greenhouse effect in double-skin facade

Energy Technology Data Exchange (ETDEWEB)

Gratia, E.; Herde, A. de [Universite Catholique de Louvain, Architecture et Climat, Louvain-La-Neuve (Belgium)

2007-02-15

In these last years, a great deal of interest has been devoted to double-skin facades due to the advantages claimed by this technology (in terms of energy saving in the cold season, high-tech image, protection from external noise and wind loads). One of the great characteristics of the double-skin facade is the greenhouse effect. We identify the factors that influence the greenhouse effect. The identified parameters are solar radiation level, orientation and shading devices use, opaque wall/window proportion of the interior facade, wind speed, colour of shading devices and of interior facade, depth of the cavity of the double-skin, glazing type in the interior facade and openings in the double-skin. We analyze the impact of these parameters on the mean air temperature evolution in the cavity. After that analyse, the article answers the question: is greenhouse effect favourable? The answer is moderate according to the double-skin orientation. (author)

The Greenhouse Effect and Climate Feedbacks

Science.gov (United States)

Covey, C.; Haberle, R. M.; McKay, C. P.; Titov, D. V.

This chapter reviews the theory of the greenhouse effect and climate feedback. It also compares the theory with observations, using examples taken from all four known terrestrial worlds with substantial atmospheres: Venus, Earth, Mars, and Titan. The greenhouse effect traps infrared radiation in the atmosphere, thereby increasing surface temperature. It is one of many factors that affect a world's climate. (Others include solar luminosity and the atmospheric scattering and absorption of solar radiation.) A change in these factors — defined as climate forcing — may change the climate in a way that brings other processes — defined as feedbacks — into play. For example, when Earth's atmospheric carbon dioxide increases, warming the surface, the water vapor content of the atmosphere increases. This is a positive feedback on global warming because water vapor is itself a potent greenhouse gas. Many positive and negative feedback processes are significant in determining Earth's climate, and probably the climates of our terrestrial neighbors.

Analysis of the internal shading in a photovoltaic greenhouse tunnel

Directory of Open Access Journals (Sweden)

Alvaro Marucci

2017-09-01

Full Text Available In recent years, the increasing interest in energy production from renewable energy sources has led to photovoltaic elements being placed on greenhouse coverings. The shading of crops by these elements can, however, cause problems regarding the normal course of agricultural activity. All studies thus far on the application of photovoltaic (PV panels as a greenhouse covering material have focused on flat roof structures. Tunnel greenhouses, due to their curved shape, do not lend themselves easily to accommodating PV panels on even part of the cover. In this study, we analysed the shading variation inside a tunnel greenhouse that was produced by applying flexible and transparent PV panels in a checkerboard arrangement. The transparent flexible PV panels are manufactured using monocrystalline silicon cells, with an efficiency of 18%, incorporated into polymers with high resistance. The PV panel dimensions are 1.116×0.165 m. The simulation software Autodesk® Autocad2010® was used for this study. The variation and distribution of the shading percentage of PV panels were analysed in relation to the surface area affected by the photovoltaic roof, the total area of the greenhouse and the section of the greenhouse. In particular, we studied the variations in the percentage of shading and the size of the shaded area on the twenty-first day of each month of the year. The results show some regularity in the shading percentage, mainly due to the curvilinear shape of the section of the greenhouse. From mid-March to mid- September, the shading in the middle of the day is almost always inside the greenhouse. In the other months of the year, it is partly inside and partly outside the tunnel greenhouse. With the photovoltaic arrangement adopted, the percentage of shading during the year never exceeds 40%.

Deployment of a Fully-Automated Green Fluorescent Protein Imaging System in a High Arctic Autonomous Greenhouse

Directory of Open Access Journals (Sweden)

Alain Berinstain

2013-03-01

Full Text Available Higher plants are an integral part of strategies for sustained human presence in space. Space-based greenhouses have the potential to provide closed-loop recycling of oxygen, water and food. Plant monitoring systems with the capacity to remotely observe the condition of crops in real-time within these systems would permit operators to take immediate action to ensure optimum system yield and reliability. One such plant health monitoring technique involves the use of reporter genes driving fluorescent proteins as biological sensors of plant stress. In 2006 an initial prototype green fluorescent protein imager system was deployed at the Arthur Clarke Mars Greenhouse located in the Canadian High Arctic. This prototype demonstrated the advantageous of this biosensor technology and underscored the challenges in collecting and managing telemetric data from exigent environments. We present here the design and deployment of a second prototype imaging system deployed within and connected to the infrastructure of the Arthur Clarke Mars Greenhouse. This is the first imager to run autonomously for one year in the un-crewed greenhouse with command and control conducted through the greenhouse satellite control system. Images were saved locally in high resolution and sent telemetrically in low resolution. Imager hardware is described, including the custom designed LED growth light and fluorescent excitation light boards, filters, data acquisition and control system, and basic sensing and environmental control. Several critical lessons learned related to the hardware of small plant growth payloads are also elaborated.

Deployment of a Fully-Automated Green Fluorescent Protein Imaging System in a High Arctic Autonomous Greenhouse

Science.gov (United States)

Abboud, Talal; Bamsey, Matthew; Paul, Anna-Lisa; Graham, Thomas; Braham, Stephen; Noumeir, Rita; Berinstain, Alain; Ferl, Robert

2013-01-01

Higher plants are an integral part of strategies for sustained human presence in space. Space-based greenhouses have the potential to provide closed-loop recycling of oxygen, water and food. Plant monitoring systems with the capacity to remotely observe the condition of crops in real-time within these systems would permit operators to take immediate action to ensure optimum system yield and reliability. One such plant health monitoring technique involves the use of reporter genes driving fluorescent proteins as biological sensors of plant stress. In 2006 an initial prototype green fluorescent protein imager system was deployed at the Arthur Clarke Mars Greenhouse located in the Canadian High Arctic. This prototype demonstrated the advantageous of this biosensor technology and underscored the challenges in collecting and managing telemetric data from exigent environments. We present here the design and deployment of a second prototype imaging system deployed within and connected to the infrastructure of the Arthur Clarke Mars Greenhouse. This is the first imager to run autonomously for one year in the un-crewed greenhouse with command and control conducted through the greenhouse satellite control system. Images were saved locally in high resolution and sent telemetrically in low resolution. Imager hardware is described, including the custom designed LED growth light and fluorescent excitation light boards, filters, data acquisition and control system, and basic sensing and environmental control. Several critical lessons learned related to the hardware of small plant growth payloads are also elaborated. PMID:23486220

Organic Matter Effect on Glomus Intrarradices in Beans (Phaseolus Vulgaris L. Growth Cultivated in Soils with Two Sources of Water under Greenhouse Conditions

Directory of Open Access Journals (Sweden)

A. K. Gardezi

2014-02-01

Full Text Available The objective of this research was to evaluate the effect of organic matter on the association with Glomus intrarradices and soil contamination on beans (Phaseolus vulgaris L.. The study was done under greenhouse conditions at the Montecillo Campus of the Postgraduate College, Mexico. Two soils were used, one irrigated with sewage water and the other one with clean water from a well. Half of the plants were inoculated with Glomus intrarradices. Vermicompost was used as a source of organic matter. There were highly significant increases (p≤0.05 in all the variables recorded due to the application of organic matter, and to the inoculation with Glomus intarradices. The irrigation source of the soils used for this experiment only had a significant effect (p≤0.05 on pod number and nitrogen fixation. The best growth and grain yield occurred with inoculated plants and supplementary organic matter.

A study of indoor radon in greenhouses in Mexico City, Mexico

International Nuclear Information System (INIS)

Guillermo Espinosa; Allan Chavarria; Jose-Ignacio Golzarri

2013-01-01

Enclosed spaces in contact with soil, the main source of radon, like greenhouses have potentially high radon ( 222 Rn) concentrations. Greenhouses are frequented by visitors and also are workplaces. The study of radon concentrations in greenhouses is, thus, a relevant concern for public health and environmental radiation authorities. For this study, the radon concentrations in 12 greenhouses in different locations within Mexico City were measured using nuclear track methodology. The detectors used for the study consisted of the well-known closed-end cup device, with CR-39 Lantrack R as detector material. The measurements were carried out over a period of one year, divided into four three-month sub-periods. The lowest and highest annual mean radon concentrations found in individual greenhouses were 17.0 and 45.1 Bq/m 3 , respectively. The annual mean averaged over all 12 greenhouses was 27.3 Bq/m 3 . No significant seasonal variation was observed. Using the highest annual mean radon concentration found in an individual greenhouse, and an equilibrium factor of 0.4, the effective dose from 222 Rn and its progenies was calculated to be 339.9 nSv/h. This corresponds to an annual dose rate of 679.8 μSv/y (0.057 WLM/y) for a worker spending 4 h a day, 5 days a week, 50 weeks a year, inside the greenhouse. For a visitor spending 12 h a year inside the greenhouse the annual dose is 2.469 μSv/y. The study of indoor radon concentrations in closed buildings such as greenhouses, which are both workplaces and open to visitors, is an important public health consideration. (author)

Receding Horizon Optimal Control of a Solar Greenhouse

NARCIS (Netherlands)