Kritika Gupta  Ashwani Kumar  Vidisha Tomer  Vikas Kumar  Mona Saini 《Journal of Food Biochemistry》2019,43(7)

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Naiming Liu  S. Emad Rezaei  Wade Aaron Jensen  Shaowei Song  Zhifeng Ren  Keivan Esfarjani  Mona Zebarjadi  Jerrold Anthony Floro 《Advanced functional materials》2019,29(38)

A β‐FeSi₂–SiGe nanocomposite is synthesized via a react/transform spark plasma sintering technique, in which eutectoid phase transformation, Ge alloying, selective doping, and sintering are completed in a single process, resulting in a greatly reduced process time and thermal budget. Hierarchical structuring of the SiGe secondary phase to achieve coexistence of a percolated network with isolated nanoscale inclusions effectively decouples the thermal and electrical transport. Combined with selective doping that reduces conduction band offsets, the percolation strategy produces overall electron mobilities 30 times higher than those of similar materials produced using typical powder‐processing routes. As a result, a maximum thermoelectric figure of merit ZT of ≈0.7 at 700 °C is achieved in the β‐FeSi₂–SiGe nanocomposite.  相似文献   

    

Anshul Vats  Mona Aggarwal  Swaran Ahuja 《Transactions on Emerging Telecommunications Technologies》2019,30(5)

In this paper, we consider a three hop hybrid visible light communication/free space optical/visible light communication (VLC/FSO/VLC) system in which the information is transmitted from a room inside the building on a VLC link toward the decode and forward (DF) relay attached to that building. The relay maps the incoming signal on the FSO link and forwards it to the other DF relay attached to the second building, which further passes it down to the user inside the room onto the VLC downlink. The VLC and FSO links follow the Lambertian emission model and Gamma‐Gamma fading statistics, respectively, under the impact of atmospheric turbulence, pointing errors, semiangle, and field of view of the detector. The performance of the three hop hybrid system is derived in terms of the closed‐form expression for the outage probability. The error performance is analyzed in terms of average symbol error probability of the considered hybrid system. Furthermore, an expression for asymptotic outage probability of the system is derived to investigate the behavior of the system at high signal‐to‐noise ratio (SNR) regimes. The impact of variation in the parameters on the hybrid VLC/FSO//VLC communication system performance is illustrated by the numerical plots.  相似文献   

    

Mahdi Mohammadi Ghaleni  Elham Tavakoli  Mona Bavarian  Siamak Nejati 《American Institute of Chemical Engineers》2020,66(11):e17019

Membranes with asymmetric wettability-Janus membranes-have recently received considerable attention for a variety of critical applications. Here, we report on a simple approach to introduce asymmetric wettability into hydrophilic porous domains. Our approach is based on the physicochemical-selective deposition of polytetrafluoroethylene (PTFE) on hydrophilic polymeric substrates. To achieve selective deposition of PTFE, we inhibit the polymerization reaction within the porous domain. We prefill the substrates with glycerol, containing a known amount of free radical inhibitor, and utilize initiated chemical vapor deposition (iCVD) for the polymerization of PTFE. We show that the glycerol/inhibitor mixture hinders the deposition of PTFE within the membrane pores. As a result, the surface of the substrates remains open and porous. The fabricated Janus membranes show stable wetting-resistant properties, evaluated through sessile drop contact angle measurements and direct contact membrane distillation (DCMD).  相似文献   

    

Ahmed M. Awad Abouelata  S. M. Aly Abdallah  Mohamed H. Sorour  Nourhan A. Shawky  Mona A. Abdel-Fatah 《应用聚合物科学杂志》2020,137(39):49190

Hollow fiber membrane (HF) is considered one of the prevalent materials for water treatment; its effectiveness is controlled by permeation and mechanical characteristics. In this study, HF membrane surface was stimulated using electrochemical technique, where binary system of stainless steel cylinder and graphite rod electrodes was used into electrolytic solution of sodium acetate 0.1 M as electrolyte. Two pH of acidic medium (pH = 3.5) and alkaline medium (pH = 8.5) were prepared and different potential between 2 and 10 V were applied. EDX analysis of HF membrane surface revealed the formation of sodium ions on the surface of HF membrane with maximum content of Na⁺ ions 1.84%. Also, HF membrane surface showed variation of roughness (R _a) as, HF membrane surface may undergo distortion by using aggressive conditions of high electric potential (7.5–10 V), The measured raw HF membrane (R _a) was 34.8 nm, while, after electrochemical modification in alkaline medium R _a showed higher values 36, 37, and 41 nm using 2, 2.5, and 5 V, respectively. While, after electrochemical modification in acidic medium (R _a) showed 35, 39, 42, 49, 52 nm for 2, 2.5, 5, 7.5, and 10 V, respectively. Moreover, tensile strength Young's modulus, break stress and break strain were measured after electrochemical modification in both acidic and alkaline mediums and maximum porosity value 76.84% was observed after 30 min in acidic medium.  相似文献   

    

Dalia Heggo  Shinichi Ookawara  Teruhisa Ohno  Toru Nakai  Yoshihisa Matsushita  Mona Gamal Eldin  Masahiro Ohshima 《加拿大化工杂志》2020,98(1):119-126

Dense photocatalyst slurry was employed for the synthesis of p-anisaldehyde under solar light irradiation. An Fe-modified rutile TiO ₂ (Fe-TiO _2, 34.5 m ²/g) photocatalyst was used as a visible-light-responsive photocatalyst. A conventional TiO ₂ (P25, 35 m ²/g) photocatalyst was also examined as a reference catalyst. XRD patterns and diffuse reflectance spectra showed that Fe-TiO ₂ consists of 100 % rutile phase and absorbs more visible light compared to P25, respectively. The catalyst powder was suspended in an ethyl acetate solution of p-methoxytoluene in the mini-reactor, with oxygen bubbling, under a solar simulator, visible light, and UV LEDs. p-anisaldehyde, as a reaction product, was analyzed by sampling using gas-chromatograph. Regardless of the light source, Fe-TiO ₂ always outperformed P25 in terms of both generation rates (GR) of p-anisaldehyde and energy requirements (ER). It was demonstrated that the highly dense Fe-TiO ₂ slurry was efficient for the synthesis under solar light owing to the small size of the reactor. The small amount of Pt and ZrO ₂ cocatalysts significantly enhanced the GR under solar light. By adopting a visible light responsive Fe-TiO ₂ photocatalyst, the mini slurry-bubble reactor under solar light achieved a high GR per catalyst mass (CM), which is one to two orders higher than that reported by most previous studies with high-power lamps.  相似文献   

    

Mona Rouhi  Moslem Mansour Lakouraj  Mehdi Baghayeri 《Polymer Composites》2019,40(3):1034-1042

Thiophene and p‐phenylenediamine were utilized as monomers to prepare low band gap copolymer and nanocomposites with core–shell construction by a simple in situ emulsion polymerization. Different devices such as Fourier transform infrared, X‐ray diffraction, scanning electron microscopy, thermal gravimetric analysis, dynamic light scattering and vibrating sample magnetometer (VSM) were used for characterizing the copolymer and nanocomposites. Band gaps were estimated from Cyclic voltammetry to be 2.1 − 1.7 eV for copolymers and nanocomposite. The results that obtained by measuring the conductivity with Four‐probe method illustrated that the electrical conductivity of the nanocomposites is considerably higher than the copolymer which is dependent on the Fe content and doping degree. The nanocomposites showed superparamagnetic behavior with high‐saturated magnetization (M_s = 10–16 emu/g). The direct electrochemistry of myoglobin (Mb) entrapped in the Nafion film on a glassy carbon electrode modified with synthesized nanocomposite had been investigated in this paper. Cyclic voltammetric results showed that a pair of well‐defined quasi‐reversible redox peaks appeared in the pH 7.0 phosphate buffer solution, which was ascribed to the direct electron transfer of Mb heme Fe(III)/Fe(II) redox couples. Also, the antioxidant activity of new nanocomposites was measured by using 2, 2‐diphenyl‐1‐picrylhydrazyl assay. POLYM. COMPOS., 40:1034–1042, 2019. © 2018 Society of Plastics Engineers  相似文献   

    

Ramesa Shafi BHAT  Amina El GEZEERY  Abir Ben BACHAN  Mona Awad ALONAZI  Leena Saleh ALSUHAIBANI  Afaf El-ANSARY 《Biocell》2019,43(2):65-71

Fluoride is a key ingredient of many psychiatric drugs like fluoxetine (Prozac^®, Fluoxetine^®). Pregnant womenfrequently use this drug as they suffer from depression and anxiety disorders during this period. Fluoxetine is able toreach the fetus through the placenta and passes to the newborn through milk. In the present study, female Wistar ratswere treated with 5, 10, and 20 mg/L fluoxetine (containing 94% fluorides) from pregnancy day 10 to day 20. Afterdelivery, the levels of the enzymatic antioxidants in the brain of their offspring at postnatal day 2 were measured. Theresults showed that, in all fluoxetine exposed groups compared with the control group, there was a significant decrease(P < 0.01) in the glutathione, catalase, glutathione S-transferases and potassium and a non- significant increase (P >0.05) in the activity of malondialdehyde and creatine kinase. The results suggest that fluoxetine may be a developmentalneurotoxicant due to presence of fluoride hence must be used carefully during pregnancy.  相似文献   

    

Mona Y. Elnaggar  El Sayed Fathy  Enas Amdeha  Medhat M. Hassan 《Polymer Engineering and Science》2019,59(4):807-813

This investigation focused on the opportunity of devulcanizing waste Rubber (WR) by ultrasonication to study the possibility of utilized as an added substance to replace with styrene‐butadiene rubber (SBR) in preparation process with the final aim of preparation new composites. The present work expects to compare the ultrasonic technique and the previous work on devulcanization by mechano‐chemical method. The influence of the ultrasonication treatment on the WR was explored by Fourier transform infrared, thermogravimetric analysis, scanning electron microscopy analysis revealed that ultrasonication was observed to be the best factor impacting the devulcanization procedure, this procedure suggests that use of specific levels of ultrasonic waves to the vulcanized rubber with a specific aim to accomplish a particular breaking of compound connections: scission of C‐S and S‐S bonds without break carbon–carbon (C‐C) bonds. Various blends of devulcanized WR with SBR was treatments with gamma ray then investigated and compared with find out the rubber giving the highest compatibility for compounding and revulcanization. In addition, a comparison of these results was made with the ones of raw SBR rubber compound. POLYM. ENG. SCI., 59:807–813, 2019. © 2019 Society of Plastics Engineers  相似文献   

    

E. S. Fathy  Mona Y. Elnaggar  Heba A. Raslan 《乙烯基与添加剂工艺杂志》2019,25(Z1):E166-E173

The effect of using gamma radiation on the prepared activated carbon (AC) from carbon black using dose 500 kGy was studied. Moreover, AC powder were blended in internal mixer to prepare thermoplastic elastomer with percentage (75/25/10) wt% based on waste polyethylene and waste rubber which irradiated before mixing at dose100 kGy separately and AC. Chemical activity of composites was improved as a result of using gamma radiation which was examined by electron spin resonance estimations. Composites were studied by different techniques, such as FTIR, mechanical, thermal, morphology, and X‐ray diffraction. The results indicated that optimistic effect of using gamma rays with improving the properties of the composites. J. VINYL ADDIT. TECHNOL., 25:E166–E176, 2019. © 2018 Society of Plastics Engineers  相似文献