scholarly journals Effect of Composite Action on the Strength of Wood Roofs

2015 ◽  
Vol 2015 ◽  
pp. 1-10
Author(s):  
Ivan A. Campos Varela ◽  
Walter H. Gerstle ◽  
Stephen Dwyer
Keyword(s):  
Laboratory Experiments ◽  
Analytical Modeling ◽  
Bending Strength ◽  
Strength Increase ◽  
Solar Photovoltaic ◽  
Composite Action ◽  
Photovoltaic Modules ◽  
Nominal Strength ◽  
Laboratory Results ◽  
Partially Composite

Engineering certification for the installation of solar photovoltaic modules on wood roofs is often denied because existing wood roofs do not meet current building codes. Rather than requiring expensive structural retrofits, we desire to show that many roofs are actually sufficiently strong if the effect of composite action produced by joist-sheathing interaction is considered. In a series of laboratory experiments using a limited number of two-by-four wood joists with and without sheathing panels, conventionally sheathed stud-grade joists, surprisingly, exhibited between 18% and 63% higher nominal strength than similar bare joists. To explain this strength increase, a simple model was developed to predict the strengths of the nailed partially composite sections, but the model only justifies a 1.4% to 3.8% increase in bending strength of joists with an allowable bending strength of 1000 psi. More testing is indicated to resolve this discrepancy between laboratory results and analytical modeling results. In addition to elucidating nonlinear partial composite behavior of existing roof systems, this paper shows that, with minor changes in roof framing practices, strength increases of 70% or more are achievable, compared to the strengths of conventionally sheathed joists.

THERMODYNAMIC EFFICIENCY OF SOLAR PHOTOVOLTAIC MODULES

2015 ◽  
Vol 14 (12) ◽  
pp. 2747-2757
Author(s):  
Istvan Farkas ◽  
Dani Rusirawan
Keyword(s):  
Thermodynamic Efficiency ◽  
Solar Photovoltaic ◽  
Photovoltaic Modules

Concentration of Impurities during Melting of Snow Made from Secondary Sewage Effluent

1986 ◽  
Vol 18 (2) ◽  
pp. 151-156 ◽  
Author(s):  
R. Zapf-Gilje ◽  
S. O. Russell ◽  
D. S. Mavinic
Keyword(s):  
Potassium Chloride ◽  
Chloride Solution ◽  
Laboratory Experiments ◽  
Field Experiments ◽  
Low Cost ◽  
Sewage Effluent ◽  
Potassium Chloride Solution ◽  
Laboratory Results ◽  
Solution Field ◽  
Concentration Of Impurities

When snow is made from sewage effluent, the impurities become concentrated in the early melt leaving the later runoff relatively pure. This could provide a low cost method of separating nutrients from secondary sewage effluent. Laboratory experiments showed that the degree of concentration was largely independent of the number of melt freeze cycles or initial concentration of impurity in the snow. The first 20% of melt removed with it 65% of the phosphorus and 90% of the nitrogen from snow made from sewage effluent; and over 90% of potassium chloride from snow made from potassium chloride solution. Field experiments with a salt solution confirmed the laboratory results.

scholarly journals Design and implementation of an I-V curvetracer dedicated to characterize PV panels

2021 ◽  
Vol 11 (3) ◽  
pp. 2011
Author(s):  
Mansour Zegrar ◽  
M’hamed Houari Zerhouni ◽  
Mohamed Tarik Benmessaoud ◽  
Fatima Zohra Zerhouni
Keyword(s):  
Photovoltaic Effect ◽  
Experimental System ◽  
Experimental Results ◽  
Solar Irradiation ◽  
Photovoltaic Module ◽  
Solar Photovoltaic ◽  
Efficient Manner ◽  
Photovoltaic Modules ◽  
Curve Tracer ◽  
Current Voltage

In recent years, solar photovoltaic energy is becoming very important in the generation of green electricity. Solar photovoltaic effect directly converts solar radiation into electricity. The output of the photovoltaic module MPV depends on several factors as solar irradiation and cell temperature. A curve tracer is a system used to acquire the PV current-voltage characteristics, in real time, in an efficient manner. The shape of the I-V curve gives useful information about the possible anomalies of a PV device. This paper describes an experimental system developed to measure the current–voltage curve of a MPV under real conditions. The measurement is performed in an automated way. This present paper presents the design, and the construction of I-V simple curve tracer for photovoltaic modules. This device is important for photovoltaic (PV) performance assessment for the measurement, extraction, elaboration and diagnose of entire current-voltage I-V curves for several photovoltaic modules. This system permits to sweep the entire I-V curve, in short time, with different climatic and loads conditions. An experimental test bench is described. This tracer is simple and the experimental results present good performance. Simulation and experimental tests have been carried out. Experimental results presented good performance.

scholarly journals Research Progress of Border for Solar Photovoltaic Modules

2015 ◽  
Author(s):  
Xingxing Wang ◽  
Haoyang Lu ◽  
Hongjun Ni ◽  
Wenfan Lu ◽  
Minqi Zhang ◽  
...  
Keyword(s):  
Research Progress ◽  
Solar Photovoltaic ◽  
Photovoltaic Modules

scholarly journals AUGMENTATION OF SOLAR WATER DISTILLER PERFORMANCE WITH PV/T

2020 ◽  
Vol 5 (1) ◽  
pp. 46-52
Author(s):  
Nguyen Viet Linh Le ◽  
Tri Hieu Le ◽  
Thi Minh Hao Dong ◽  
Van Vang Le ◽  
Dinh Tung
Keyword(s):  
Solar Collector ◽  
Solar Photovoltaic ◽  
Solar Still ◽  
Photovoltaic Panel ◽  
Water Distillation ◽  
Solar Water ◽  
Photovoltaic Modules ◽  
Solar Distillation ◽  
Distillate Yield ◽  
Flat Plate Collector

Recently, due to global warming and urbanization, there are many major cities that may face the challenge of day zero next decades. Obviously, water is an indispensable component for maintaining life on the earth. Although portable water is required of the hour, the quantity of available freshwater is impacted significantly by sea-level rise and pollution from industrialization. As a consequence of the global water crisis, different methods for clean water production from brackish water have been studied and developed in practice, however, the solar distillation of water is the most economical and desirable approach due to this method utilize solar energy that is the environmentally friendly and economical resource. Over the last 15 years, the impressive price drop of the photovoltaic solar collector (PV/T) makes them popular and easy to access. As a result, the employment of PV/T in solar stills is emerging as a potential device for water distillation. Therefore, in this paper, an active solar distiller combined with a photovoltaic panel has been reviewed for improvement of the distillate yield and effectiveness of solar photovoltaic. This review work presents a variety of studies on various types of solar still (for example conventional solar still (CSS), double slope solar still (DSSS), stepped solar distiller, and cascade solar still) couples with different solar water collectors (such as flat plate collector (FPC) and evacuated tubes collector (ETC)) and solar photovoltaic modules. It is obtained that the hybrid PV/T active solar still improves the distillate yield, energy efficiency, and exergy efficiency as compared to passive mode. The cooling method enhances the performance of the photovoltaic solar collector as well as the productivity of solar still. Moreover, the environmental economic estimation reveals that the solar still coupled with the PV/T mitigated considerably the amount of CO2. It can be stated that it is suitable to commercialize the hybrid PV/T active solar still for supplying not only electricity but drinking water also. Finally, this review paper also suggests the scope for the research in the future.

Performance of solar photovoltaic modules under arid climatic conditions: A review

Solar Energy ◽  
2018 ◽  
Vol 174 ◽  
pp. 409-421 ◽  
Author(s):  
Maxime Mussard ◽  
Mohamed Amara
Keyword(s):  
Climatic Conditions ◽  
Solar Photovoltaic ◽  
Photovoltaic Modules
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