111 research outputs found

    Modelling of a novel Stand-Alone, Solar Driven Agriculture Greenhouse Integrated With Photo Voltaic /Thermal (PV/T) Panels

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    This is the author accepted manuscriptThis paper presents an analytical study of a new stand-alone agriculture greenhouse (GH) system. This system utilizes the excess solar radiation (more than that required by the plants for photosynthetic process) to generate electricity via a set of Photo Voltaic/Thermal (PV/T) units which are placed on the GH roof and south side. In addition to electricity generation, PV/Ts reduce the cooling load of the GH and help the system to be naturally ventilated. The system recovers the GH air humidity, including the plants transpiration, and uses it as irrigating water. Two coupled mathematical models are developed using MATLAB. The first model calculates the absorbed and transmitted solar radiation by/through each GH surface for a Clear Sky Day. The results of the first model are used as inputs to the second one that predicts the GH performance (GH surfaces and air temperatures, air relative humidity, air velocity, water production, electricity production and power consumption). These models are applied on climate conditions of Zagazig city, Sharqia, Egypt. The results show that the system presents a good solution for water shortage in Egypt as it has the ability to provide suitable climate conditions for plant growth (high quality and quantity) and produce enough water for irrigation purposes.British CouncilScience & Technology Development Fund (STDF), Egyp

    Decarbonisation using hybrid energy solution: case study of Zagazig, Egypt

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    This is the final version. Available on open access from the publisher via the DOI in this record.In this study, an analysis is carried out to determine the optimal application of multiple renewable energy resources, namely wind and solar, to provide electricity requirements for green smart cities and environments. This was done to determine the potential of renewable energy to provide clean, economically viable energy for the case study of Zagazig, located at 30â—¦340 N 31â—¦300 E in the North East of Egypt. The relevant data surrounding the production of energy were collected, including the meteorological data from NASA, and specifications regarding renewable resources including solar panels, wind turbines, and storage batteries. Then a hybrid model was constructed consisting of Photovoltaics (PV) panels, wind turbines, a converter, and storage batteries. Once the model was constructed, meteorological data were added alongside average daily demand and cost of electricity per kWh. The optimal solution for Zagazig consisted of 181,000 kW of solar panels feeding directly into the grid. This system had the lowest Net Present Cost (NPC) of the simulations run of US$1,361,029,000 and a net reduction of 156,355 tonnes of CO2 per year.British CouncilScience, Technology, and Innovation Funding Authority (STIFA) of Egyp

    Simulation of agriculture greenhouse integrated with on-roof Photo-Voltaic panels: case study for a winter day

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    This is the author accepted manuscript.This paper investigates analytical study for an agricultural greenhouse (GH) integrated with Photo Voltaic/Thermal (PV/T) units in its roof and south wall in addition to HumidificationDehumidification system (HDH). This system uses the extra solar radiation to generate electricity which is used in HDH system to condensate water recovered from plant transpiration and use it in irrigation. This system provides plants with a proper climate conditions and its requirements of solar radiation and water. MATLAB is used to develop a mathematical model based on energy equations to simulate the GH performance. The results predict that the system can be self-sufficient of energy and can provide proper conditions for the plant growth for the climate conditions of winter in Zagazig.British CouncilScience & Technology Development Fund (STDF), Egyp

    Early and total yield enhancement of the globe artichoke using an ecofriendly seaweed extract-based biostimulant and PK fertilizer

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    This is the final version. Available from MDPI via the DOI in this record.This study evaluated the effect of phosphorus and potassium (PK) fertilizer levels and foliar seaweed extract on early and total yield productivity and the growth of globe artichoke plants. Field experiments were conducted over two seasons on loamy–clay soil at the vegetable research farm, of the Faculty of Agriculture, Alexandria University, Egypt. Fertilizer levels of 0, 25, 50 and 75 mL L−1, and seaweed extract concentrations of 0, 5 and 10 mg L−1, individually and in combination, were used. Globe artichoke plants treated with PK liquid fertilizer, with and without seaweed extract, showed critical increases in growth (plant height and number of leaves per plant as well as foliage dry weight), yield, and some chemical constituents compared to untreated plants. The PK3 fertilizer level and 10 mL L−1 seaweed extract as a foliar spray showed greater effects than other combinations.King Saud University Researchers Supporting Projec

    Towards a sustainable greenhouse: Review of trends and emerging practices in analyzing greenhouse ventilation requirements to sustain maximum agricultural yield

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    This is the final version. Available on open access from MDPI via the DOI in this recordCultivation in open fields mainly depends on the location and time of farming, which itself highly depends on the quality and quantity of water for irrigation, weather conditions and soil characteristics. Water resources are highly dependent on the limited freshwater resources from the groundwater system, or rainwater. Countries in MENA (Middle East and North Africa) rely mostly on desalination technologies for agriculture due to water scarcity. Therefore, greenhouse (GH) agriculture can be developed to succeed in dealing with the water scarcity and provide sufficient sources of agricultural products as a sustainable solution. These indoor agriculture facilities, which are enclosed by transparent covers, can produce different sources of fruits and vegetables, using a controlled amount of water. By reducing the exchange rate of air with the outside environment, which is known as the confinement effects, greenhouses generate a suitable environment for the plants to grow under transparent covers to trap the sunlight. This raises the inside temperature above the maximum threshold levels, especially within the warm season due to the high solar radiation intensity, having an adverse influence on the microclimate conditions and consequently the crop growth. In order to sustain maximum agricultural yield, greenhouse ventilation is an important parameter in which its trends and emerging practices were reviewed in this studyBritish Council - EgyptScience & Technology Development Fund (STDF) of Egyp

    Analysing the material suitability and concentration ratio of a solar-powered parabolic trough collector (PTC) using Computational Fluid Dynamics

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    This is the final version. Available on open access from MDPI via the DOI in this recordSolar-powered desalination is a sustainable solution for countries experiencing water scarcity. Several studies have presented different solutions to provide cleaner production in desalination systems. Parabolic trough collector (PTC) is one of these solutions that has proven to be superior among solar concentrators. Furthermore, a number of studies have investigated the use of PTC for distillation of saline water in response to water scarcity. In this study, a modified PTC model was developed, in which the heat exchanger was replaced by a condensation tube to reduce the energy consumption, and a black layer was introduced to the surface of the receiver to enhance its absorptance. As a reference case, the system productivity according to average solar intensities in Zagazig, located at 30°34′N 31°30′E in the North East of Egypt, is estimated. The results indicated that the maximum production rate that can be attained is 1.72 kg/hr. Then, the structure of the system is evaluated with the aid of Computational Fluid Dynamics (CFD) modelling, in order to enhance its productivity. Many materials are examined and the results recognised copper as the most suitable material amongst marine grade metals (i.e., aluminium, galvanised steel and stainless steel) to construct the receiver tube. This is due to its superior thermal performance, satisfactory corrosion resistance, and acceptable cost. Afterwards, the selected receiver tube was employed to identify the optimal Concentration Ratio (CR). Consequently, a CR of 90.56 was determined to be the optimum value for Zagazig and regions with similar solar radiation. As a result, the system’s productivity was enhanced drastically, as it was estimated that a maximum production rate of 6.93 kg/hr can be achieved.Science, Technology, and Innovation Funding. Authority (STIFA) of EgyptBritish Counci

    A Zero-Liquid Discharge Model for a Transient Solar-Powered Desalination System for Greenhouse

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    This is the final version. Available on open access from MDPI via the DOI in this recordThe need for sustainable desalination arises from fast-occurring global warming and intensifying droughts due to increasing temperatures, particularly in the Middle East and North African (MENA) regions. Lack of water resources has meant that the countries in these regions have had to desalinate seawater through different sustainable technologies for food supplies and agricultural products. Greenhouses (GH) are used to protect crops from harsh climates, creating a controlled environment requiring less water. In order to have a sustainable resilient GH, a zeroliquid-discharge system (ZLD) was developed by using solar still (SS) desalination techniques, humidification-dehumidification (HDH), and rainwater harvesting. An experiment was designed and carried out by designing and manufacturing a wick type solar still, together with an HDH system, implemented into a GH. Using a pyrometer, the solar intensity was recorded, while the microclimate conditions (temperature and relative humidity) of the GH were also monitored. The GH model was tested in the UK and was shown to be a successful standalone model, providing its water requirements. In the UK, for one solar still with a surface area of 0.72 m2 , maximum amount of 58 mL of distilled water was achieved per day. In Egypt, a maximum amount of 1090 mL water was collected per day, from each solar still. This difference is mainly due to the differences in the solar radiation intensity and duration in addition to the temperature variance. While dehumidification generated 7 L of distilled water, rainwater harvesting was added as another solution to the greenhouse in the UK, harvested a maximum of 7 L per day from one side (half the area of the greenhouse roof). This helped to compensate for the less distilled water from the solar stills. The results for the developed greenhouses showed how GHs in countries with different weather conditions could be standalone systems for their agricultural water requirement.British CouncilScience and Technology Development Fund (STDF) of Egyp

    Analysis of Inlet Configurations on the Microclimate Conditions of a Novel Standalone Agricultural Greenhouse for Egypt Using Computational Fluid Dynamics

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    This is the final version. Available from MDPI via the DOI in this record. Water shortage, human population increase, and lack of food resources have directed societies towards sustainable energy and water resources, especially for agriculture. While open agriculture requires a massive amount of water and energy, the requirements of horticultural systems can be controlled to provide standard conditions for the plants to grow, with significant decrease in water consumption. A greenhouse is a transparent indoor environment used for horticulture, as it allows for reasonable control of the microclimate conditions (e.g., temperature, air velocity, rate of ventilation, and humidity). While such systems create a controlled environment for the plants, the greenhouses need ventilation to provide fresh air. In order to have a sustainable venting mechanism, a novel solution has been proposed in this study providing a naturally ventilating system required for the plants, while at the same time reducing the energy requirements for cooling or other forced ventilation techniques. Computational fluid dynamics (CFD) was used to analyse the ventilation requirements for different vent opening scenarios, showing the importance of inlet locations for the proposed sustainable greenhouse system.British Council (BC) of UKScience, Technology, and Innovation Funding Authority (STIFA) of Egyp

    Post-Harvest Enhancing and Botrytis cinerea Control of Strawberry Fruits Using Low Cost and Eco-Friendly Natural Oils

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    This is the final version. Available from MDPI via the DOI in this record.This work investigates an experimental study for using low-cost and eco-friendly oils to increase the shelf life of strawberry fruit. Three natural oils were used: (i) Eucalyptus camaldulensis var obtuse, (ii) Mentha piperita green aerial parts essential oils (EOs), and (iii) Moringa oleifera seeds n-hexane fixed oil (FO). Furthermore, a mixture of EOs from E. camaldulensis var obtusa and M. piperita (1/1 v/v) was used. The treated fruits were stored at 5 °C and 90% relative humidity (RH) for 18 days. HPLC was used to analyse the changes in phenolic compounds during the storage periods. The effects of biofumigation through a slow-release diffuser of EOs (E. camaldulensis var obtusa and M. piperita), or by coating with M. oleifera FO, were evaluated in terms of control of post-harvest visual and chemical quality of strawberry fruits. The post-harvest resistance of strawberry fruits to Botrytis cinerea fungal infection was also evaluated. As a result, the EO treatments significantly reduced the change in visual and chemical quality of strawberry fruit. Additionally, changes in the titratable acidity of moringa FO-coated strawberry fruits were delayed. EO treatments improved total soluble solids, total phenols, ascorbic acid, antioxidants and peroxidase. E. camaldulensis var obtusa and M. piperita (1/1 v/v) EO-vapour fruit exhibited a slower rate of deterioration, compared to other treatments in all tested, in two experiments. The lowest colour change (ΔE) was observed inthe fruit treated with E. camaldulensis var obtusa EO and M. oleifera FO. HPLC showed changes in phenolic compounds’ concentration, where p-coumaric acid, caffeic acid, gallic acid, ferulic acid and ellagic acid were mostly identified in the fruits treated with the oils. SEM examination confirmed the potential decrease in fungal growth as the fruits were treated with EOs. In conclusion, the treatment of EOs during different storage periods showed promising characterisations for strawberry fruit quality.Deanship of Scientific Research, King Saud Universit

    Global, regional, and national burden of stroke and its risk factors, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019

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    Background: Regularly updated data on stroke and its pathological types, including data on their incidence, prevalence, mortality, disability, risk factors, and epidemiological trends, are important for evidence-based stroke care planning and resource allocation. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) aims to provide a standardised and comprehensive measurement of these metrics at global, regional, and national levels. Methods: We applied GBD 2019 analytical tools to calculate stroke incidence, prevalence, mortality, disability-adjusted life-years (DALYs), and the population attributable fraction (PAF) of DALYs (with corresponding 95% uncertainty intervals [UIs]) associated with 19 risk factors, for 204 countries and territories from 1990 to 2019. These estimates were provided for ischaemic stroke, intracerebral haemorrhage, subarachnoid haemorrhage, and all strokes combined, and stratified by sex, age group, and World Bank country income level. Findings: In 2019, there were 12·2 million (95% UI 11·0–13·6) incident cases of stroke, 101 million (93·2–111) prevalent cases of stroke, 143 million (133–153) DALYs due to stroke, and 6·55 million (6·00–7·02) deaths from stroke. Globally, stroke remained the second-leading cause of death (11·6% [10·8–12·2] of total deaths) and the third-leading cause of death and disability combined (5·7% [5·1–6·2] of total DALYs) in 2019. From 1990 to 2019, the absolute number of incident strokes increased by 70·0% (67·0–73·0), prevalent strokes increased by 85·0% (83·0–88·0), deaths from stroke increased by 43·0% (31·0–55·0), and DALYs due to stroke increased by 32·0% (22·0–42·0). During the same period, age-standardised rates of stroke incidence decreased by 17·0% (15·0–18·0), mortality decreased by 36·0% (31·0–42·0), prevalence decreased by 6·0% (5·0–7·0), and DALYs decreased by 36·0% (31·0–42·0). However, among people younger than 70 years, prevalence rates increased by 22·0% (21·0–24·0) and incidence rates increased by 15·0% (12·0–18·0). In 2019, the age-standardised stroke-related mortality rate was 3·6 (3·5–3·8) times higher in the World Bank low-income group than in the World Bank high-income group, and the age-standardised stroke-related DALY rate was 3·7 (3·5–3·9) times higher in the low-income group than the high-income group. Ischaemic stroke constituted 62·4% of all incident strokes in 2019 (7·63 million [6·57–8·96]), while intracerebral haemorrhage constituted 27·9% (3·41 million [2·97–3·91]) and subarachnoid haemorrhage constituted 9·7% (1·18 million [1·01–1·39]). In 2019, the five leading risk factors for stroke were high systolic blood pressure (contributing to 79·6 million [67·7–90·8] DALYs or 55·5% [48·2–62·0] of total stroke DALYs), high body-mass index (34·9 million [22·3–48·6] DALYs or 24·3% [15·7–33·2]), high fasting plasma glucose (28·9 million [19·8–41·5] DALYs or 20·2% [13·8–29·1]), ambient particulate matter pollution (28·7 million [23·4–33·4] DALYs or 20·1% [16·6–23·0]), and smoking (25·3 million [22·6–28·2] DALYs or 17·6% [16·4–19·0]). Interpretation: The annual number of strokes and deaths due to stroke increased substantially from 1990 to 2019, despite substantial reductions in age-standardised rates, particularly among people older than 70 years. The highest age-standardised stroke-related mortality and DALY rates were in the World Bank low-income group. The fastest-growing risk factor for stroke between 1990 and 2019 was high body-mass index. Without urgent implementation of effective primary prevention strategies, the stroke burden will probably continue to grow across the world, particularly in low-income countries. Funding: Bill & Melinda Gates Foundation
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