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In Egyptian desert, growing plants is difficult due to harsh climate (hot at the daytime and cold at the night), infertile soil, low average rainfall and lack of fresh water for irrigation purposes. A set of simple transparent solar stills are integrated with a new solar driven agriculture greenhouse (GH). The stills are placed at the GH roof to use the extra solar radiation (above that required for plant photosynthesis process) for water desalination. In addition to water desalination concept the solar still units even reduce the cooling load during the daytime. A net of aluminum metal coated with black colour is placed on the base of the solar still units to raise the water temperature (enhance desalination process) and provide partially shading for the GH. Using aluminum net decreases also the number of solar still units required to produce the required amount of GH fresh water leading to a significant cost reduction.The main objectives of this work are sizing of the aluminum net, spacing between solar still units to obtain the threshold of plant requirements. Also fresh water production and greenhouse climatic conditions that plant needs (temperature, relative humidity, air velocity and amount of oxygen) are simulated.Numerical simulation was carried out for the hottest day of Borg Elarab, Alexandria (Egypt). 

AbstractThe present paper experimentally explores the influence of the fiber hybridization and layering sequence on crashworthiness behavior and deformation history of polymer/metal thin-walled pipes. Jute (J)/glass (G) reinforced epoxy over wrapped aluminum (Al) pipes were prepared via hand wet wrapping then subjected to axial quasi-static compressive loads. The load versus displacement plots and crashing indicators, i.e. peak crushing load ($${\mathrm{F}}_{\mathrm{ip}}$$ F ip ), mean crushing load ($${\mathrm{F}}_{\mathrm{m}}$$ F m ), total energy absorption ($$\mathrm{U})$$ U ) , specific energy absorption $$\left(\mathrm{SEA}\right)$$ SEA , and crush force efficiency $$\left(\mathrm{CFE}\right)$$ CFE were determined. Experimental results revealed that the maximum $$\left(\mathrm{SEA}\right)$$ SEA was recorded for Al/2J/4G/2J pipe with a value of about 42.92 kJ/g, with an enhancement of 20.56% in $$\left(\mathrm{SEA}\right)$$ SEA compared with pure Al-pipes. Al/2J/4G/2J specimens display the maximum ($$\mathrm{U})$$ U ) , $$\left(\mathrm{SEA}\right)$$ SEA , and $$\left(\mathrm{CFE}\right)$$ CFE and could be employed as energy absorbing members in automobiles.

Utilization of daylight in indoor spaces creates opportunities for energy savings and is linked to increasing productivity in the workplace. This sensitive aspect in environmentally aware architectural design depends on many interfacing factors. In this research, ceiling geometry is investigated as an element that can provide control to natural light, achieved through reflection and diffusion of the external and internal reflected components of daylight. This paper presents a generic optimization procedure for architects that aids in generation and finding of curvilinear and mesh ceiling forms. The objective was to maximize daylight uniformity ratios. A genetic algorithm was developed and coded in LUA, a versatile scripting language. Radiance simulation software was employed as the backend daylighting performance calculation engine, and Ecotect as the front end form input and visualization tool. Conclusions about the optimum ceiling geometry and form for a designed example case were drawn. The presented method provided architects with a variety of choices for designs which are weighed through daylighting performance. Results showed that this approach offers a robust and yet precise form finding method.

This paper proposes two approaches for optimal scheduling of unit commitment (UC) considering reserve generating for competitive market. The particle swarm optimization (PSO) technique is used to find out the solution of both optimal UC and power generation problems, simultaneously. The two proposed approaches depend on various sigmoid functions to obtain the binary values PSO. The first approach takes the fuzzification of generation costs as a sigmoid function; while the second approach takes the fuzzification of power generation as sigmoid function. A proposed objective function is presented dependent on the exponential form which leads to fast convergence of PSO solution. This objective aims to minimize the generation costs as well as maximize their own profit while all load demand and generation reserve are satisfied. Hence, the generations companies (GENCO) schedule their generators with objective maximize their own profit with regard for system social benefit. This means that, this objective helps GENCO to make a decision, how much power and reserve should be sold in markets and how to schedule generators in order to receive the maximum the profit. Different comparisons are carried out using various standard test systems to show the capability of the two proposed sigmoid approaches and the proposed objective function compared with other techniques

AbstractThe Fram Strait is the only deep gateway between the Arctic Ocean and the Nordic Seas and thus is a key area to study past changes in ocean circulation and the marine carbon cycle. Here, we study deep ocean temperature, δ18O, carbonate chemistry (i.e., carbonate ion concentration [CO32−]), and nutrient content in the Fram Strait during the late glacial (35,000–19,000 years BP) and the Holocene based on benthic foraminiferal geochemistry and carbon cycle modeling. Our results indicate a thickening of Atlantic water penetrating into the northern Nordic Seas, forming a subsurface Atlantic intermediate water layer reaching to at least ∼2,600 m water depth during most of the late glacial period. The recirculating Atlantic layer was characterized by relatively high [CO32−] and low δ13C during the late glacial, and provides evidence for a Nordic Seas source to the glacial North Atlantic intermediate water flowing at 2,000–3,000 m water depth, most likely via the Denmark Strait. In addition, we discuss evidence for enhanced terrestrial carbon input to the Nordic Seas at ∼23.5 ka. Comparing our δ13C and qualitative [CO32−] records with results of carbon cycle box modeling suggests that the total terrestrial CO2 release during this carbon input event was low, slow, or directly to the atmosphere.

Petroleum oil pollution is a worldwide problem that results from the continuous exploration, production, and consumption of oil and its products. Petroleum hydrocarbons are produced as a result of natural or anthropogenic practices, and their common source is anthropogenic activities, which impose adverse effects on the ecosystem’s nonliving and living components including humans. Phytoremediation of petroleum hydrocarbon-polluted soils is an evolving, low-cost, and effective alternative technology to most traditional remediation methods. The objective of this study is to evaluate the phytoremediation potentiality of Vinca rosea for crude oil-contaminated soil by understanding its properties and involvement in the enhanced degradation of crude oil. The remediation potentiality was determined by evaluating the total petroleum hydrocarbon degradation percentage (TPH%) and changes in the molecular type composition of saturated and aromatic hydrocarbon fractions. TPH% was estimated gravimetrically, and changes in the molecular type composition of saturated and aromatic fractions were measured using gas chromatography and high-performance liquid chromatography, respectively. Sulfur concentration was measured using X-ray fluorescence. Cadmium and lead quantification was measured using Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). The results revealed that V. rosea enhanced total petroleum hydrocarbon (TPH) degradation and altered the molecular composition of the crude oil. The saturated hydrocarbons increased and the aromatic hydrocarbons decreased. The saturated hydrocarbon fraction in the crude oil showed a wider spectrum of n-paraffin peaks than the oil extracted from unplanted and V. rosea-planted soils. Polyaromatic hydrocarbon degradation was enhanced in the presence of V. rosea, which was reflected in the increase of monoaromatic and diaromatic constituents. This was parallel to the increased sulfur levels in planted soil. The determination of sulfur and heavy metal content in plant organs indicated that V. rosea can extract and accumulate high amounts from polluted soils. The ability of V. rosea to degrade TPH and alter the composition of crude petroleum oil by decreasing the toxicity of polyaromatic hydrocarbons in soil, as well as its capability to absorb and accumulate sulfur and heavy metals, supports the use of plant species for the phytoremediation of crude oil-polluted sites.

Connection between electric power networks is essential to cover any deficit in the generation of power from any of them. The exchange powers of the plants during load disturbance should not be violated beyond their specified values. This can be achieved by installing load frequency control (LFC); therefore, this paper proposes a new metaheuristic-based approach using a skill optimization algorithm (SOA) to design a fractional-order proportional integral derivative (FOPID)-LFC approach with multi-interconnected systems. The target is minimizing the integral time absolute error (ITAE) of frequency and exchange power violations. Two power systems are investigated. The first one has two connected plants of photovoltaic (PV) and thermal units. The second system contains four plants, namely, PV, wind turbine, and two thermal plants, with governor dead-band (GDB) and generation rate constraints (GRC). Different load disturbances are analyzed in both considered systems. Extensive comparisons to the use of chef-based optimization algorithm (CBOA), jumping spider optimization algorithm (JSOA), Bonobo optimization (BO), Tasmanian devil optimization (TDO), and Atomic orbital search (AOS) are conducted. Moreover, statistical tests of Friedman ANOVA table, Wilcoxon rank test, Friedman rank test, and Kruskal Wallis test are implemented. Regarding the two interconnected areas, the proposed SOA achieved the minimum fitness value of 1.8779 pu during 10% disturbance on thermal plant. In addition, it outperformed all other approaches in the case of 1% disturbance on the first area as it achieved ITAE of 0.0327 pu. The obtained results proved the competence and reliability of the proposed SOA in designing an efficient FOPID-LFC in multi-interconnected power systems with multiple sources.

Organic photovoltaics (OPVs) have received considerable attention over the past two decades as a promising alternative to their inorganic counterparts. Although the power conversion efficiency (PCE) of OPVs has rapidly increased in the last ten years exceeding 18%, higher PCEs are still needed to commercialize this emerging technology. The weak light absorption, particularly at wavelengths outside the visible region, and the recombination losses of the photo-generated charge carriers represent the major challenges for the PCE of OPVS. The light harvest and survival of the photo-generated charge carriers within OPVs are restricted to multiple factors such as material properties and device engineering. The application of different types of inorganic nanoparticles (INPs) in OPVs has been reported by many researchers as an effective strategy to overcome most of the PCE limitations. Here, a comprehensive overview of the progress in the performance of OPVs due to the application of different INPs over the past decade is provided. This review also presents an in-depth analysis of the efficiency loss pathways at the different steps of the photovoltaic effect and how INPs can address these issues resulting in PCE enhancement of OPVs. Finally, the impacts of this approach on the stability and cost of the device in addition to challenges and outlook are discussed.