Anti-reflection Coating Solar Cell Structure Based on Conductive Nanoparticles

In this paper, we investigate for the first time antireflection coating structure for silicon solar cell where CNPs (conductive nanoparticles) film layer is sandwiched between a semi-infinite glass cover layer and a semi-infinite silicon substrate. The transmission and reflection coefficients are derived by the transfer matrix method and simulated for values of unit cell sizes, gab widths in visible and near-infrared radiation. In addition, the absorption, reflection coefficients are examined for several angles of incidence of the TE (transverse electric) polarized guided waves. Numerical results provide an extremely high absorption, if nanoparticles are suitably located and sized. The absorptivity of the structure achieves 100% at gab width of 3.5 nm and CNP layer thickness of 150 nm

Hydration Characteristics of Limestone Filled Cement Pastes

The physico-mechanical properties of hardened limestone-filled cement pastes were studied. Five filled-cements were prepared from 0, 5, 10, 15 and 20 wt. % of limestone and OPC. The water of consistency of filled-cement pastes was 0.275, 0.275, 0.275, 0.272, and 0.270, respectively. The pastes are moulded into one inch cubic moulds and left within the moulds at 100% relative humidity for 24 h, then demoulded and cured under tap water for 3, 7, 28, and 90 days. At each hydration time, the combined water, bulk density, total porosity and compressive strength of the hardened filled-cement pastes were determined. Some selected filled-cement pastes were investigated using differential thermal analysis (DTA) and scanning electron microscope (SEM) Techniques. Addition of limestone to Portland cement causes an increase of hydration at early ages inducing a high early strength, but it can reduce the later strength due to the dilution effect. The results indicate that the addition of limestone up to 5 wt. % improves the physico-mechanical properties of ordinary Portland cement which acts as a nucleating agent and accelerates the hydration of filled cement pastes. The addition of 5 wt. % limestone can be used in the production of portland cement according to the international specifications. On the other side, the addition of 10-20 wt. % limestone can be used in the production of blended or mixed cements

Decreasing maize production-consumption gap by intercropping with upland rice using different planting densities under deficit irrigation

A two-year field experiment was conducted in 2018 and 2019 at Gemmiza Agricultural Research Station (Lat. 31.03° N, Long. 30.88° E, 8 m a.s.l.); Gharbia Governorate; Egypt. The aim was to use untraditional sowing method to intercrop maize with upland rice using three maize planting densities (25, 37.5 and 50% of its recommended density) and application of two deficit irrigation treatments (irrigation every 9 and 12 days), in addition to irrigation every 6 days (control) and to study its effect on the yield of both intercrops, competitive relationships and farmer’s income. The results indicated that the highest value of rice yield and its components were found under irrigation every 6 days and 25% maize planting density intercropped with rice. Whereas, the highest value of maize yield and its components were found under irrigation every 9 days and 50% maize planting density intercropped with rice, which also obtained the highest land and water equivalent ratios, area time equivalent ratio, and land equivalent coefficient. Furthermore, the highest total income and monetary advantage index were obtained under irrigation every 9 days and 50% maize planting density intercropped with rice. Thus, these results implied that intercropping maize with upland rice can solve part of the maize production-consumption gap through increasing its production without using additional lands or water.  Keywords: Land and water equivalent ratios, percentage of land saved, area time equivalent ratio, land equivalent coefficient, monetary advantage index, Rice, Maize, Egyp

Kinetic modelling of methanol synthesis over commercial catalysts: A critical assessment

Kinetic modelling of methanol synthesis over commercial catalysts is of high importance for reactor and process design. Literature kinetic models were implemented and systematically discussed against a newly developed kinetic model based on published kinetic data. Deviations in the sensitivities of the kinetic models were explained by means of the experimentally covered parameter range. The simulation results proved that an extrapolation of the working range of the kinetic models can lead towards significant simulation errors especially with regard to pressure, stoichiometric number and CO/CO$_{2}$-ratio considerably limiting the applicability of kinetic models frequently applied in scientific literature. Therefore, the validated data range for kinetic models should be considered when detailed reactor simulations are carried out. With regard to Power-to-Methanol processes special attention should be drawn towards the rate limiting effect of water at high CO$_{2}$ contents in the syngas. Moreover, it was shown that kinetic models based on data measured over outdated catalysts show significantly lower activity than those derived from state-of-the-art catalysts and should therefore be applied with caution for reactor and process simulations. The plausible behavior of the herein proposed kinetic model was demonstrated by a systematic comparison towards established kinetic approaches within both, an ideal kinetic reactor and an industrial steam cooled tubular reactor. Relative to the state-of-the-art kinetic models it was proven that the herein proposed kinetic model can be applied over the complete industrially relevant working range for methanol synthesis

Validation of the Arabic version of the Social Communication Questionnaire

Validated screening and diagnostic tools for autism spectrum disorder for use in Arabic-speaking individuals are scarce. This study validated the Arabic version of the Social Communication Questionnaire. The total study sample included 206 children with autism spectrum disorder and 206 typically developing children (73.8% male; mean age: 8.5 (standard deviation = 2.6) years). The mean Social Communication Questionnaire total score was significantly higher in autism spectrum disorder children than in typically developing children (p < 0.0001). Scores on the three Social Communication Questionnaire subscales also differed significantly between the groups (p < 0.001). Of the 39 items, 37 were endorsed significantly more often in the autism spectrum disorder group. The total Social Communication Questionnaire score did not vary by age or gender. Internal consistency was excellent (alpha = 0.92). In the receiver operating characteristic analysis, the area under the curve for the total score showed excellent discrimination between autism spectrum disorder and typically developing children (area under the curve = 0.95; 95% confidence interval: 0.93–0.97). The areas under the curve for the scale subscores were 0.923 (95% confidence interval: 0.898–0.949) for the social interaction score, 0.872 (95% confidence interval: 0.838–0.905) for the communication score, and 0.856 (95% confidence interval: 0.819–0.893) for the repetitive behaviors score. The findings support the use of the Arabic Social Communication Questionnaire to successfully differentiate children with clinically diagnosed autism spectrum disorder using the established cutoff value for the English version.The authors would like to thank all the staff of the autism centers and schools who contributed in distributing and collecting the SCQ forms. They also would like to thank Western Psychological Services (WPS) staff for their help during the process of translating and reviewing the Arabic SCQ. They acknowledge Jennifer Holmes, ELS, for medical editing. The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The study was funded by the Qatar National Research Fund (NPRP 6-093-3-024)

Analysis and Design of E-shape Meander Line Antenna for LTE Mobile Communications

the meander line antenna (MLA) is an electrically small antenna. Electrically small antennas pose several performance related issues such as narrow bandwidth, low gain and high cross polarization levels. In this paper, we analysis and design an E-shape MLA as anew shape to achieve wider bandwidth and smaller gain at 2.5 GHz compared to the classical MLA. Parametric study has been done for the effect of changing each variable in the antenna structure and study the effect of this change on the antenna performance. The best` performance of separate variables is combined at the end which give suboptimal design. Professional design software (HFSS) is used to design and optimize the antenna and MATLAB codes were written to determine the resonant frequency and the bandwidth for each study in this paper

Lipase production by Fusarium culmorum in solid state fermentation

Fusarium is a large genus of filamentous fungi which cause some of the most important diseases in agricultural and horticultural crops. This fungus is considered to be a useful producer of enzymes from an industrial point of view. In the present study, lipase production by Fusarium culmorum SY6 was investigated under solid-state fermentation (SSF). Among the several agronomic wastes, corn cob hulls and tomato pulp supported the highest yield of lipase (170 and 165 U/g of dry substrate, respectively) after five days of incubation. It was determined that pH 9 and 60°C gave optimumenzyme activity. The F. culmorum SY6 strain grown in SSF in a simple medium proved to be a promising microorganism for lipase production