MATHEMATICAL MODELING OF A DOUBLE PASS UNDERFLOOR HEATING SYSTEM

Toward a green building construction, the underfloor heating by solar energy in multi-apartments buildings was considered. A system of double pass underfloor heating with evacuated tube solar collector was modeled. The used energy is a renewable energy that does not affect the environment. The system modeled consist of an evacuated tube solar collector for heating the water, the underfloor heating system consist of two lined up pipes to help in the case of low inlet water temperatures, the control unit used to manage the heating system and save energy in case of excess solar radiation. The governing equations for the system based on energy conservation were written and simulated iteratively. It has been found that at low temperatures the required mass flow rate of hot water increases dramatically, as a result of insufficient heat to cover the heating load of the space, this system allow the double pass heat transfer mode to be switched on to reduce the flow velocity and allow the workability of the system to be valid at a lower temperatures. Also in the case of low heating loads, the amount of hot water required to cover the heat requirement of the space will be very low. The reduction in the heating load will allow the system to send a part of the hot fluid to the storage tank to store the hot water and achieve a lower temperature water flow. The simulation of such model could give a clear idea about the workability of the underfloor heating system, the required solar collector area, and manage the energy within the system. A more detail analyses of the DPUFHS is the topic of a current study. The underfloor is considered with multi-pass arrangement, and the control unit will simulate transient conditions of the system. A more realistic system will be considered by accounting for the floor heat losses and the thermal storage in the walls and floor

Workplace Violence on Physicians and Nurses: Causes and Pre-Violence Suggested Solutions

One of the important occupational health problems is violence. Violence is more prevalent among physicians and nurses in psychiatric and emergency departments in Jordan public hospitals. Causes of this phenomenon are associated with different causatives such as hospitals facilities (including beds, medication, oxygen… etc.), hospital staff, ministry of health and patients with their families. In this work violence on physicians and nurses in Jordan hospitals is analyzed based on the causes of violence. Solutions are searched upon the causatives of these actions not only on education, training and toughening punishment. Results of this work showed that 58.3 % of violence is due to hospital facilities and staff, 25% government actions and 17.7 % due to patients and their families. This work suggests investing more in healthcare institutions, provide more skilled staff, introduce a management procedure following incidents, preventive policies and improving health institutional facilities by applying programs for medicine inventory control, human factors and management techniques

Experimental Analysis of Atmospheric Water Harvester Using Ammonia Vapour Absorption System

There are increasing concerns for the promising future of atmospheric water harvesters (AWH). AWH have been analysed theoretically and experimentally using different technologies such as Vapour Compression (VC) Thermoelectric (TE), Sorption (absorption, adsorption) and shape-based techniques. These techniques are suffering from low water harvesting or high energy consumption. The ammonia vapour absorption system (VAS) (which can be operated using renewable energy sources) has not yet been analysed experimentally. In this study, the AWH based on ammonia VAS has been studied experimentally, the effect of air flow velocity and ambient conditions have been analysed. The comparison between the existing techniques and VAS was performed to explore the possibility of implementing biomass, geothermal and solar energy in generating water from atmosphere, thus reducing the cost of the m3 of water produced

Using of Adhesives and Binders for Agglomeration of Particle Waste Resources

This review presents the usage of adhesives and binders for agglomeration of particle materials, including waste, in order to obtain strong bodies. The binding materials were classified into three categories: inorganic binders, organic binders, and compound binders. Many examples of the agglomeration effect of binders in view of their adhesive and thickening reveal that they have a significant impact on the qualities and use of waste lumps. Binders for fine waste granulation, briquetting, and pelletizing were demonstrated in-depth. In all cases, the mechanical strength of the agglomerates produced was increased. It was observed that the majority of the additives may be easily obtained from waste resources, posing a minimal environmental risk

Review of Agricultural-Related Water Security in Water-Scarce Countries: Jordan Case Study

Food security is an essential issue for human survival and civilization. Whenever food–water security is in doubt, the community is negatively affected. Globally, Jordan is the second most water-stressed country, located in an arid, politically divided and migratory active Middle East region that lacks the access to valuable natural resources such as fertile soils. Jordan receives about 78 m3/person/year from renewable resources, which represents 1% of the world water share. Jordan’s Water Minister declared that a 50 million m3 lack of drinking water is to be faced next year; this shortage is added to the lack of irrigation water, which yields food insecurity and food price fluctuations that wear out the consumer. The aim of this study is to provide a comprehensive overview of the impact of agricultural cropping patterns and water security by analyzing the most relevant national databases. The study results will contribute to the development of national policy in order to strategize the aid programs and adaptation measures for more sustainable planning in the Jordanian agri-food sector

Analysis of Partially Evacuated Solar Still System under Jordan Climate

The pressing need for reducing the global warming effects from the emission of greenhouse gases necessitates the use of renewable energy where possible. Solar distillers are devices with a promising future. In this work, an experimental setup (solar distiller) was constructed and equipped with a mirror, basin, glass cover, compressor, sensors and controllers to study the partial evacuation effects on different solar distillation parameters and the production capacity under the Jordanian climate. The test rig was tested for three different water levels (1, 2 and 3 cm), and four pressure values (1, 0.9, 0.8 and 0.7 atm) under the Jordanian climate. The detailed experimental results strongly correlate with the results previously published in literature. The modifications performed on the system doubled the previously attained efficiency. These improvements in the solar distiller will favor the application of the vacuum pressure principle in many different applications, such as the water extraction from the atmospheric air

An Experimental Investigation into Improving the Performance of Thermoelectric Generators

Low-temperature heat sources have become increasingly popular in recent years, particularly for energy generation. The majority of thermal devices in the market (including devices using solar energy, geothermal energy, waste energy, and so on) transform heat into electricity indirectly, requiring mechanical work before producing power. Through the Seebeck effect, the technology that employs a thermoelectric generator (TEG) may directly transform heat energy into electricity. The TEG technology provides several advantages, including compactness, quietness, and the absence of moving components. TEGs have a low thermal and electrical efficiency, which is one of their main drawbacks. Therefore, the performance of a thermoelectric generator is improved by employing liquid evaporation heat transfer in this manuscript. The performance of the thermoelectric was examined experimentally and compared to the liquid evaporation mode under varied heat flux values and different modes of heat transfer in terms of free and forced convection with and without fins. The experimental results revealed that when compared to free convection without fins, adopting forced liquid evaporation convection would improve TEG voltage variation by 435.9%

Atmospheric Water Harvesting Technology: Review and Future Prospects

Atmospheric water harvesting (AWH) devices represent a fruitful hope to cope with water shortage problem throughout the world. The vast development in AWH technology and the wide spread of the various AWH techniques will largely contribute in the implementation of AWH machines in different household, agricultural and industrial applications. In the last decades a huge amount of research has been done on AWH methods with amazing differences in results that miss lead the readers and even researchers. In this study the AWH theoretical technology developments, various AWH methods and the various AWH machines in the market are reviewed. A comparison between the different theoretical methods is presented, concentration on unifying results based on area and energy consumption per harvested amount is performed for clear judgment on the different published data. Gaps between theory and market available devices are stated with recommendations for further development in AWH technology

Hierarchical Risk Communication Management Framework for Construction Projects

Risk, as an effect of uncertainty, is associated with every human activity. Like any other industry, construction companies are eager to reduce the uncertainty of reluctant events. A well-planned risk communication system could contribute to the success of a construction project. A proper announcement protocol could be a mitigating lever for identified or unidentified risks during planning and monitoring processes. This research aims to present a risk communication management system (RCMS) for construction companies involved in large projects. The proposed model includes a step-by-step communication procedure considering the authority level within the organisational hierarchical structure. The model aims to remove the ambiguity of risk communications during the construction process under uncertain conditions. It leaves no or little room for the emergence of unplanned risks. The proposed communication structure has been implemented in GRC cladding construction projects, and the risk communication time and response have been significantly improved

Integrated Eco-Friendly Outdoor Cooling System – Case Study of Hot-Humid Climate Countries

This research proposed an integrated eco-system for conditioning an outdoor public area (park or sport) in a hothumid environment. It is accomplished by the use of a dehumidifier control machine driven by renewable solar power; after which air is distributed throughout a ducting system. The system will harvest moisture from the air, utilize it for drinking water production and plants irrigation as well as deliver low temperature, low humidity ratio air for controlling the outdoor air, which results in a comfortable outdoor relative humidity and temperature (24 °C, 50% RH). The Integrated Eco-Friendly Cooling System (IEFCS) is a sustainable self-dependent in energy and water sources. It provides a positive impact on the microclimate of the site, assists in night illumination, supplies water for drinking, plant irrigation, and allows people to enjoy a thermally comfortable atmosphere. The advantages include low maintaining cost as well as the possibility to be scaled and implemented anywhere according to the selected location