Effect of seed layers on low-temperature,chemical bath deposited ZnO nanorods-based near UV-OLED performance

Low-temperature wet chemical bath deposition (CBD) method is one of the most efficient and least hazardous solution-based techniques which is widely employed to grow ZnO NRs. In CBD method, a seed layer is usually deposited on the substrate. In this paper, high quality ZnO and aluminum doped ZnO (AZO) seed layers are sputtered on the indium tin oxide (ITO) coated glass. In continue, aligned ZnO NRs are grown on the AZO and ZnO seed layers via CBD technique. The effect of the growth time and seed layer on the physical properties of as-grown ZnO NRs are investigated. According to the results, the seed layer plays an essential role on the growth orientation and growth rate of the ZnO NRs. The ZnO NRs grown on AZO seed layer are more aligned rather than ZnO seed layer due to their higher texture coefficients. The relative photoluminescence (PL) intensity ratio of near band emission (NBE) to deep level emission (DLE) (I_NBE/I_DLE) for the ZnO NRs grown on AZO and ZnO seed layers are calculated as 7.45 and 2.62, respectively. To investigate the performance of the as-grown ZnO NRs, near ultraviolet organic light-emitting diodes (UV-OLEDs) using ZnO NRs array as n-type material and poly [2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenylene-vinylene] (MEH-PPV) conjugated polymer as p-type material have been fabricated. The total concentration of traps ($N_t$), the characteristic energies ($E_t$) and the turn-on voltages for the devices with the structures of ITO/AZO/ZnO NRs/MEH-PPV/Al (device A) and ITO/ZnO/ZnO NRs/MEH-PPV/Al (device B) are attained 7.65 × 10¹⁶ and 7.75 × 10¹⁶ cm^?3, 0.232 and 0.206 eV, 23 and 21 V, respectively. Moreover, based on the electroluminescence (EL) spectra, the NBE peaks for device A and B are obtained nearly in the wavelengths of 382 and 388 nm, respectively. Finally, various charge carrier transportation processes of prepared UV-OLEDs have been studied, systematically.     

Synthesis of Bio-Based Polyamide/Acid-Functionalized Multiwalled Carbon Nanotube Nanocomposites Using Vanillin

Synthesis of bio-based polyamide/acid-functionalized multiwalled carbon nanotube nanocomposites (PA/FCNT NCs) is reported in this investigation. New aliphatic–aromatic bio-based polyamide (PA) was synthesized through direct polycondensation reaction between bio-based diacid derived from a renewable resource; vanillin and diamine containing ether linkages. To obtain a homogeneous dispersion of multiwalled carbon nanotubes (MWCNTs) in the PA matrix, acid-functionalized MWCNTs (FCNTs) were used and PA nanocomposites with three different FCNT contents (1, 5 and 7?wt%) were prepared. The resulting NCs were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and thermogravimetric analysis (TGA).     

Amidohydroxylated polyester with biophotoactivity along with retarding alkali hydrolysis through in situ synthesis of Cu/Cu2O nanoparticles using diethanolamine

In this research, polyester fabric was modified through in situ synthesis of Cu/Cu₂O nanoparticles (NPs) in one single step processing using diethanolamine. This introduced amide and hydroxyl active groups on the polyester surface, adjusted pH, aminolyzed, and improved the surface activity of polyester. Copper sulfate was used as precursor, sodium hypophosphite as a reducing agent and polyvinylpyrrolidone as a stabilizer in a chemical reduction route at boil as a facile and cost‐effective approach. The central composite design was also utilized to optimize the processing conditions and study the effect of each variables on the weight gain, color change, and wettability of the treated fabrics. FESEM and mapping, EDX, XRD, and FTIR analysis confirmed effective assembling of Cu/Cu₂O NPs on the amidohydroxylated polyester surface. The optimum treated fabric showed excellent antibacterial properties on both Staphylococcus aureus and Escherichia coli. In addition, a very good photocatalytic activity towards degradation of methylene blue solution obtained after 24 h sunlight irradiation. Further, the hydrophilicity, mechanical properties and stability of the treated fabrics in concentrated sodium hydroxide improved through formation of amidohydroxyl active groups, amidoester cross‐linking and nanocross‐linking within polymeric chains through in situ synthesis of Cu/Cu₂O. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44856.     

A Location Privacy-Preserving Method for Spectrum Sharing in Database-Driven Cognitive Radio Networks

The great attention to cognitive radio networks (CRNs) in recent years, as a revolutionary communication paradigm that aims to solve the problem of spectrum scarcity, prompts serious investigation on security issues of these networks. One important security concern in CRNs is the preservation of users location privacy, which is under the shadow of threat, especially in database-driven CRNs. To this end, in this paper, we propose a Location Privacy Preserving Database-Driven Spectrum-Sharing \((\hbox {L-PDS}^2)\) protocol for sharing the spectrum between PUs and SUs in a database-driven CRN, while protecting location privacy of both primary and secondary users, simultaneously. We also present two specific algorithms as implementations of \(\hbox {L-PDS}^2\) protocol. Our analytical results for the privacy protection capability of \(\hbox {L-PDS}^2\) protocol prove that it provides location privacy preservation with very high probability for users of both networks. Moreover, the simulation results show that the proposed algorithms are efficient in terms of run time.     

Synthesis of superabsorbent hydrogel nanocomposites for use as hemostatic agent

Uncontrolled hemorrhage continues to be the major cause of death in trauma. In this study, the authors prepared hydrogel nanocomposites (HNCs) using three different nanoparticles, SiO₂, natural clinoptilolite (nC), and Ca²⁺-modified clinoptilolite (mC). Fast-swelling superabsorbent hydrogel was used as a matrix of NCs. The hydrogel and HNCs were characterized by FTIR, XRD, FE-SEM, and TGA. The hemocompatibility of HNCs was evaluated by hemolysis test and blood cells function. HNC formed a physical barrier by dehydrating the injury site and concentrating clotting factors. Additionally, highly charged nanoparticles, promoted local hemostasis by activating the intrinsic pathway of the blood coagulation cascade.     

Impacts of broadband and selected infrared wavelength treatments on inactivation of microbes on rough rice

This study investigated the effects of broadband and selected infrared (IR) wavelength treatments of rough rice on microbial inactivation. Rough rice was treated at different IR wavelengths and product-to-emitter distances (110, 275, and 440 mm) followed by tempering at 60°C for 4 hr. The total mold and aerobic plate counts (APC) on non-treated and treated samples were determined. Significant total mold reductions of 1.14 and 3.11 log CFU/g were obtained after IR heating using broadband and selected wavelengths, respectively (p < .05). The most significant reduction of APC using selected IR wavelength was 1.09 log CFU/g; the broadband IR wavelength had no effect on the mean APC. The IR treatments followed by tempering step resulted in greater reductions of total mold counts and APC (4.03 and 3.50 log CFU/g) in comparison to IR treatments without tempering (3.11 and 1.09 log CFU/g). Overall, bacteria showed more resistance to IR treatments than molds.     

Activity-based costing in flexible manufacturing systems with a case study in a forging industry

The objective of this paper is to apply the activity-based costing (ABC) approach together with traditional costing (TC) for parts costing in flexible manufacturing systems (FMS) with the A(2) level of automation. We propose a new model for the implementation of ABC using the product cost tree concept. First, the required resources and activities for each part are recorded, and then their costs are calculated using the appropriate cost formulae. This model was applied in a forging industry. A comparison and analysis between ABC and TC was then carried out based on the computational results obtained from the case study. The results indicate that the ABC outputs are more reliable than the TC outputs, and thus the ABC approach is a more acceptable tool for parts costing in FMS.     

Thermal degradation behavior of poly(vinyl chloride) in the presence of poly(glycidyl methacrylate)

The thermal degradation behavior of poly(vinyl chloride) (PVC) in presence of poly(glycidyl methacrylate) (PGMA) has been studied using continuous potentiometric determination of the evolved HCl gas from the degradation process from one hand and by evaluating the extent of discoloration of the degraded samples from the other. The efficiency of blending PGMA with dibasic lead carbonate (DBLC) conventional thermal stabilizer has also been investigated. A probable radical mechanism for the effect of PGMA on the thermal stabilization of PVC has been suggested based on data reported by FTIR and elemental analyses. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008