Terahertz antenna design for wearable applications

In this chapter, an overview of wearable antennas operating in the terahertz frequency range made from two-dimensional materials such as graphene is presented. The antenna designs are analyzed in realistic environments in the proximity of human skin. Characteristics such as highly miniaturized and flexible substrate materials of the antennas coupled with excellent antenna performance make these wearable antennas a strong candidate in applications of short-range wireless communication near the human body. The resonant properties of the two-dimensional materials are investigated using their electronic properties. Wireless communication in the terahertz frequency, high-resolution imaging for bio-sensing and disease management, and spectroscopy are anticipated to be some of the early beneficiaries of wearable and flexible antennas. Further investigations in this area of research provide interesting opportunities not only for antenna engineers but also for material scientists and physicists

Meristem Tip Culture for In Vitro Eradication of Grapevine Leaf Roll-associated Virus-1 (GLRaV-1) and Grapevine Fan Leaf Virus (GFLV) from Infected Flame Seedless Grapevine Plantlets

Grapevine (Vitis vinifera cv. Flame Seedless) was found infected with viral diseases; showing thicker leaves than normal, brittle, with margins rolled downwards and yellowish, which were identified as Grapevine Leaf roll-associated Virus-1 (GLRaV-1). Other symptoms were observed on leaves. The infected leaves showed malformation with abnormal gather primary veins, giving the leaf the appearance of an open fan, including yellowing and mosaic pattern on leaves, or bright yellow bands along major veins. Fan-shaped leaves were associated with mosaic or vein banding symptoms, these observations were identified as Grapevine Fan leaf Virus (GFLV). Both viruses were detected using Double Antibody Sandwich – Enzyme Linked Immuno Sorbent Assay (DAS-ELISA) and Reverse Transcription-Polymerase Chain Reaction (RT-PCR). The use of tissue culture was investigated as a mean to eliminate the two viruses. Virus-free plants were produced within six months using meristem tip culture. Woody plant (WP) medium supplied with benzyl amino purine BAP (4.44 µM) was used for shoot proliferation, and indole butyric acid IBA (0.2 µM) for plantlets rooting. Before acclimatization, the plantlets were submitted to DAS-ELISA and RT-PCR in order to evaluate virus eradication. GLRaV-1 and GFLV free plants (95 and 90 %, respectively) were obtained from the optimum size (0.5 mm) of meristem tips (as indexed by DAS-ELISA). Of these, 82.5 and 75 % plants were found negative for GLRaV-1 and GFLV, respectively, as diagnosed by RT-PCR. RT-PCR and meristem tip culture were found to be reliable methods for virus indexing and elimination of GLRaV-1 and GFLV

Chemical Profile of Cyperus laevigatus and Its Protective Effects against Thioacetamide-Induced Hepatorenal Toxicity in Rats

Cyperus species represent a group of cosmopolitan plants used in folk medicine to treat several diseases. In the current study, the phytochemical profile of Cyperus laevigatus ethanolic extract (CLEE) was assessed using UPLC-QTOF–MS/MS. The protective effect of CLEE at 50 and 100 mg /kg body weight (b.w.) was evaluated on hepatorenal injuries induced by thioacetamide (100 mg/kg) via investigation of the extract’s effects on oxidative stress, inflammatory markers and histopathological changes in the liver and kidney. UPLC-QTOF–MS/MS analysis of CLEE resulted in the identification of 94 compounds, including organic and phenolic acids, flavones, aurones, and fatty acids. CLEE improved the antioxidant status in the liver and kidney, as manifested by enhancement of reduced glutathione (GSH) and coenzyme Q10 (CoQ10), in addition to the reduction in malondialdehyde (MDA), nitric oxide (NO), and 8-hydroxy-2′-deoxyguanosine (8OHdG). Moreover, CLEE positively affected oxidative stress parameters in plasma and thwarted the depletion of hepatorenal ATP content by thioacetamide (TAA). Furthermore, treatment of rats with CLEE alleviated the significant increase in plasma liver enzymes, kidney function parameters, and inflammatory markers. The protective effect of CLEE was confirmed by a histopathological study of the liver and kidney. Our results proposed that CLEE may reduce TAA-hepatorenal toxicity via its antioxidant and anti-inflammatory properties suppressing oxidative stress

Simulation and modeling of the influence of temperature on CdS/CdTe thin film solar cell

Semiconductor materials cadmium sulfide (CdS) and cadmium telluride (CdTe) are employed in the fabrication of thin film solar cells of relatively excessive power conversion efficiency and low producing price. Simulations of thin film CdS/CdTe solar cell were carried out using SCAPS-1D. The influence of temperature field on the variation of CdTe solar cell parameters such as current–voltage, capacitance–voltage characteristics and the external quantum efficiency was investigated theoretically. For use temperatures, one obtains the external quantum efficiency has the same profiles. However, the effect of the temperature on the Mott-Schottky curves is slightly noted by variations on the characteristics. This conclusion can be used by solar cell manufacturers to improve the solar cell parameters with the biggest possible gain in device performance

Application of date palm leaves compost and plant growth promoting rhizobacteria for controlling faba bean root rot disease in New Valley, Egypt

This study was designed to investigate the effect of date palm leaves compost (DPLC) individually and/or in combined with plant growth promoting rhizobacteria (PGPR) for controlling faba bean root rot disease caused by Rhizoctonia solani and Fusarium solani under greenhouse and field conditions. The obtained data indicate that DPLC at different concentrations significantly decreased root rot incidence either under artificial infection in pot or natural infection in field as well as increased growth and yield parameters during growing season 2013-2014. Date palm leaves compost at 8 ton/ feddan (feddan = 1.038 acres) recorded the highest protection against root rot disease and gave the highest increased of plant growth and yield parameters. On the other hand, PGPR viz. Bacillus megaterium, B. cereus and Pseudomonas fluorescens individually or mixed significantly decreased root rot incidence under greenhouse and field conditions. The mixed of PGPR strains significantly suppressed the diseases more than used alone of them. Plant growth promoting rhizobacteria increased efficacy of DPLC for controlling root rot disease in faba bean more than the applied of DPLC or PGPR alone under greenhouse and field conditions during both tested seasons as well as increased of nodulations, growth and yield parameters. The application mixed of PGPR strains and DPLC at 8 ton/feddan recorded the highest reduction of root rot incidence and increase of nodulations, growth and yield parameters during both growing seasons. 

Evaluation of palm fiber components an alternative biomass wastes for medium density fiberboard manufacturing

This work deals with assessing the date palm component wastes as alternative lignocellulosic material for production of Medium density fiberboards, in order to establish economic and balance between production/consumer ratio at different provinces rather than Upper Egypt. Palm leafs and palm frond was used as Medium density fiberboards precursors. Different urea formaldehyde levels (10-14%/fiber) and pressing pressure (25-35 bar) were applied in this evaluation. The acceptable interaction of palm fibers component with urea formaldehyde was optimized by characterizing its differential scanning calorimetry and thermogravimetric analysis, in comparison with commercial used sugarcane bagasse fibers. The promising Medium density fiberboards Panel is obtained from palm frond fibers and its mechanical and water resistance properties fulfill the ANSI standard for high grade Medium density fiberboards wood products, especially on applying urea formaldehyde level 12-14%, and pressing pressure, 35 bar. It is interesting to note that, applying higher pressing pressure together with 12% urea formaldehyde level provided palm frond-based Medium density fiberboards with static bending properties, higher than commercial bagasse-based Medium density fiberboards. The insignificant effect of pressing pressure was noticed on water swelling property and free-HCHO of Medium density fiberboards panels.  Where, both type of fibers have the same water swelling property (reached ~ 10%), and free-HCHO (~ 27 mg/100g board)

Developing Improved Corrosion-Resistant AA5083—BN/WC Composites for Tribological Applications

In this study, corrosion-resistant AA5083—BN/WC composites were developed for tribological applications through adequate control of the reinforcement content (WC and BN) in the matrix (AA5083 alloy). The effects of 6% and 12% tungsten carbide (WC) as well as 6% and 12% boron nitride (BN) additions on the corrosion behavior of AA5083 aluminum composite in 3.5% NaCl solution were carried out. Electrochemical techniques such as cyclic potentiodynamic polarization (CPP), changes in the chronoamperometric current with time (CCT), and electrochemical impedance spectroscopy (EIS) were utilized. The polarization results showed that the addition of 6% WC to the AA5083 alloy matrix improved its resistance to corrosion (RP). Rp exhibited an additional increase by adding 12% WC to the matrix. The values of RP were observed to increase for the AA5083 composite when adding 6% BN, and the highest RP values were recorded for the composite that contains 12% BN. The results obtained by the CPP method were confirmed by CCT and EIS measurements, where the presence of WC and BN protected the developed AA5083- BN/WC composites against corrosion. The corrosion resistance revealed an additional improvement with an increase in WC and BN content from 6% to 12%. The results also confirm that pitting corrosion decreased in the presence of WC and BN in the fabricated composites

Synthesis, Microstructure Investigation, Mechanical and Tribological Behaviour of the AA5083–WC Composite

In this study, AA5083–WC composites were developed by ball milling followed by hot consolidation. The microstructures of the developed composites were investigated using XRD, SEM, EDX, and EBSD. The developed composites exhibited a homogeneous dispersion of WC particulates in the AA5083 matrix without any interactions at the matrix/reinforcement interface. The results confirmed the development of a refined equiaxed grain structure of AA5083–WC composites where the EBSD results revealed an average grain size of 4.38 µm and 3.32 µm for AA5083–6%WC (AW-6) and AA5083–12%WC (AW-12) composites, respectively. The results showed that incorporating WC particulates in the AA5083 alloy matrix significantly improved the compressive stress–strain behaviour and considerably enhanced the resistance to wear and friction. The AA5083–12%WC (AW-12) composite displayed the maximum strength and the highest resistance to wear and friction, whereas the as-milled AA5083 alloy (AW-0) exhibited the lowest strength and the least resistance to wear and friction. The AA5083–12%WC (AW-12) composite exhibited the optimum mechanical and tribological behaviour of the developed composites, making it a promising candidate for tribological applications