Potential of sodium alginate/titanium oxide biomembrane nanocomposite in DMFC application

A proton exchange membrane was synthesized consuming a sodium alginate biopolymer as the matrix and titanium oxide as the nanofiller. The titanium oxide content varied from 5 to 25 wt%. The biomembrane nanocomposite performs better than the pristine sodium alginate membrane based on liquid uptake, methanol permeability, proton conductivity, ion exchange capacity, and oxidative stability outcomes. The unique properties of sodium alginate and titanium oxide lead to outstanding interconnections, thus producing new materials with great characteristics and enhanced performance. The highest proton conductivity achieved in this study is 17.3 × 10^‐3 S cm^‐1, which performed by SAT5 (25 wt%) membranes at 70°C. An optimal content of titanium oxide enhances the conductivity and methanol permeability of the membrane. Additionally, the hydrophilicity of pure sodium alginate is greatly reduced and achieves a good liquid uptake capacity and swelling ratio. The characteristics of the SA/TiO₂ biomembrane nanocomposite were determined with field emission scanning electron microscope, Fourier transform infrared, X‐ray diffraction, thermal gravimetric analysis/differential scanning calorimetry, and mechanical strength analysis.     

Carbon nanoflake hybrid for biohydrogen CO2 capture: Breakthrough adsorption test

Biohydrogen gas is a hot topic for H₂ fuel at present. However, removal of the unwanted CO₂ through adsorption is required before any system is supplied with high-purity H₂ gas. Herein, we prepared a novel carbon nanoflake hybrid for efficient biohydrogen CO₂ capture by combining the advantages of carbon, metal oxide, and amine. Among the samples, SH800 showed a remarkable high CO₂ adsorption capacity of 29.8 wt.% (6.77 mmol/g) at 25°C and 1 atm, the highest ever reported at low pressure and temperature. The regeneration experiment also demonstrated robust reversibility over five cycles in the absence of heat treatment. Moreover, it displayed a highly accessible adsorption site with a Brunauer-Emmett-Teller (BET) surface area of 600 m²/g and an optimal 6.6-nm average mesopore structure. Another hybrid named SH500 was also developed. This hybrid showed a comparable CO₂ uptake of 27.8 wt.%, being competitive to SH800 but with entirely different chemical properties. Both samples were analyzed by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), BET, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy, (XPS) and were tested for CO₂ capture through a breakthrough experiment. A highly porous solid adsorbent was also produced via soft-template synthesis. In summary, the correct amount of dynamic factors, such as high surface area, mesopore-micropore morphology, activation temperature, metal hybridization, and N moieties, played a major role in the carbon engineering of CO₂ adsorbent.     

Application of expanded polystyrene (EPS) in buildings and constructions: A review

Expanded polystyrene (EPS) is one of the building material capable of enhancing the design and structural integrity of the building. Since its recognition as conventional insulating material in 1950s, EPS has been experiencing swift progress in other new implementations. Currently, EPS is utilized in many building structures owing to its sustainability benefit and improvement in terms of energy efficiency, durability, and indoor environmental quality. This article provides an overview on the application of EPS as aggregates in lightweight concrete, decorative tiles and molding, panel application (structural insulated panels (SIPs) and composite SIPs), and embankment backfilling. Also, this article attempts to describe the properties of EPS in terms of fire behavior, mechanical properties, chemical resistant, water and moisture absorption, and their toxicity to the human and environment. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47529.     

Nature-inspired optimization algorithms for community detection in complex networks: a review and future trends

Telecommunication Systems - Over the past couple of decades, the research area of network community detection has seen substantial growth in popularity, leading to a wide range of researches in the...     

Expression of stress regulator and virulence genes of Cronobacter sakazakii strain Yrt2a as a response to acid stress

Food Science and Biotechnology - This research aimed to evaluate the effect of acid stress on the expression of stress regulator (grxB and rpoS) and virulence (ompA, hfq, and cpa) genes of...     

Evaluation of Quaternized polyvinyl alcohol/graphene oxide-based membrane towards improving the performance of air-breathing passive direct methanol fuel cells

Graphene oxide (GO) nanosheets are introduced to a Quaternized polyvinyl alcohol (QPVA) polymer matrix to obtain an anion exchange membranes (AEMs) for application of fuel cells. QPVA/GO nanocomposite membranes provide desirable properties such as low fuel uptake and permeability, excellent ionic conductivity, and cell performance, all of which are favorable for AEMs based on our previous works. Passive direct methanol fuel cells (DMFCs) are recognized as suitable technologies for use in portable devices. Nevertheless, the commercialization of DMFCs remains restricted due to a number of issues related to the conventional membrane; one of these issues is high fuel crossover problems due to high fuel uptake and permeability of Nafion membrane. This study aimed to expand the potential applications of QPVA/GO nanocomposite membranes in air-breathing passive DMFCs. The ionic conductivity, methanol uptakes (MUs), and permeabilities of self-synthesis QPVA/GO nanocomposites are examined to evaluate the ability to operate in methanol atmosphere. At 30°C, the ionic conductivity of the membranes reached 1.74 × 10⁻² S cm⁻¹. The MUs and permeabilities were as low as 35% and 7.6 × 10⁻⁷ cm² s⁻¹, respectively. The performance of air-breathing passive DMFCs bearing QPVA/GO nanocomposite membrane is much higher compared to conventional membranes. The maximum power density of air-breathing passive DMFCs was achieved 27.2 mW cm⁻² under the optimum condition of 2 M methanol + 4 M KOH at 70°C. Single-cells could be sustained for 1000 hours. This article is the first to optimize and highlight the performance air-breathing passive DMFCs by using a QPVA-based membrane.     

Performance investigation of a small Savonius-Darrius counter-rotating vertical-axis wind turbine

This paper describes the study of a small vertical-axis wind turbine (VAWT) with a combined design of Darrius and Savonius counter-rotating rotors. The main purpose of this study is to improve the extraction capabilities of a single-rotor VAWT by using two distinct rotor designs while adopting the counter-rotating technique. Given that the conversion capabilities and operational speed of the existing wind turbines are still limited, the current technique is used to enhance the efficiency and expand the operating wind speed range of the VAWT. The Darrius and Savonius counter-rotating rotors were exposed to a similar upstream wind speed using a centrifugal blower. It was found that the Savonius-Darrius counter-rotating rotor was able to operate effectively, particularly at the low-speed wind. By looking at the individual performance of the rotors, it was observed that the conversion efficiency of the H-type rotor increases as the wind speed increases. However, in the case of the S-type rotor, it is higher at lower wind speed and tends to decrease as the operating speed increases. Thus, the maximum efficiency of the S-type rotor was achieved at low speed, whereas the H-type rotor has achieved its maximum efficiency at the highest operating wind speed. The average efficiency of the present Savonius-Darrius counter-rotating rotor has been improved to reach almost 42% and 30% more efficiency in terms of torque and power, respectively.     

Electrodeposition of metallic molybdenum and its alloys – a review

Aqueous electrodeposition may represent a more economical and reliable technique to fabricate Mo coatings than the alternatives (electrodeposition from fused-salt baths and other available methods). However, studies on the aqueous electrodeposition of pure metallic Mo are rather limited due to its oxophilic nature, catalytic behaviour for the hydrogen evolution reaction and high tendency for polymerisation, especially in acidic media. To date, researchers have tended to focus on the aqueous electrodeposition of Mo alloys. These alloys usually contain <51% Mo. The factors that influence the quality of Mo deposits and the difficulties in the electrodeposition process are reviewed here. This review not only presents a survey of existing literature on the electrodeposition of metallic Mo coatings but also provides a basis for any future exploration.     

Fabrication of Bone Scaffolds from Cockle Shell Waste

Bone scaffold is a three‐dimensional structure composed of materials that could enhance bone regeneration. Bone scaffolds were prepared using freeze‐drying by varying the cockle shell powder concentration where sodium alginate acted as matrix. The scaffolds were then characterized by X‐ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, texture analyzer, and liquid displacement method. The bioactivity of the scaffolds was evaluated by immersion into a simulated body fluid solution. Cockle shell powder concentrations affected the bone scaffold characteristics. The increment of the powder concentrations improved the physicochemical properties and bioactivity of the scaffolds.     

Characterizations and electrical conductivity of (poly[vinyl chloride])/(poly[ethylene oxide]) conductive films: The effect of carbon black loading and poly(ethylene glycol) diglycidyl ether

The effect of carbon black (CB) loading filled (poly[vinyl chloride])/(poly[(ethylene oxide]) (PVC/PEO) conductive films with and without poly(ethylene glycol) diglycidyl ether (PEGDE) was studied. The PVC/PEO/CB and PVC/PEO/PEGDE/CB conductive films were prepared by a solution casting method. The results indicate that the addition of PEGDE of PVC/PEO/CB/PEGDE conductive films exhibited higher tensile properties, electrical conductivity, and thermal stability compared with PVC/PEO/CB conductive films. The scanning electron microscope micrographs of PVC/PEO/PEGDE/CB conductive films showed a rough surface and a good distribution of CB on the surface of PVC/PEO/CB conductive films. Fourier‐transform infrared spectrum showed that the interaction between the PVC/PEO films and the CB‐PEGDE phase on the surface of the conductive films does not change the functional group of the PVC/PEO/PEDGE/CB conductive films. J. VINYL ADDIT. TECHNOL., 24:139–146, 2018. © 2016 Society of Plastics Engineers