Environmental impact assessment of bio-hydrogenated diesel from hydrogen and co-product of palm oil industry

Bio-hydrogenated diesel (BHD) is a second generation biofuel that can be produced from vegetable oil and hydrogen via hydroprocessing. BHD is considered as one of alternative and renewable energy. This work presents evaluation of environmental impacts of BHD produced from palm fatty acid distillate (PFAD) compared to fatty acid methyl ester (FAME). Greenhouse gas emission, energy consumption, and overall environmental impacts are assessed. System boundary is from palm oil cultivation to BHD production. The functional unit is defined as 1 kg of fuel produced at the plant. The results indicate that energy consumption of BHD-PFAD is 1.18 times higher than that of BHD-FAME, while giving GHG emission 13.56 times lower than that of BHD-FAME. The results of overall environmental impacts indicated that BHD-PFAD was 3.58 greater than that of BHD-FAME.     

Full-wave rectifiers based on operational transconductance amplifiers

The implementation of full-wave rectifiers using operational transconductance amplifiers (OTAs) as only main active circuit elements is presented in this paper. The proposed scheme makes use of the characteristic of the differential amplifier inside the OTA and avoids the use of diodes. The typical problems of the OTA circuit, the input voltage swing limitation and the temperature dependence of the OTA transconductance gain, have been improved. Simulation and experimental results demonstrate the performance of the proposed rectifier are included.     

Solid‐State Conversion Reaction to Enhance Charge Transfer in Electrochromic Materials

Interface engineering has attracted great interest and is essential for the fabrication of thin‐film devices, such as smart windows. In this study, a solid‐state conversion reaction for the development of an interlayer enriched with lithium peroxide (Li₂O₂) is presented for an electrochromic device. We demonstrate that efficient lithium insertion and electron transport can be achieved by the inclusion of a Li₂O₂‐rich interlayer between an active electrochromic material and Li ion solid‐state electrolyte layer. The presence of a Li₂O₂‐rich interlayer enhances electrochromic efficiency, kinetics, optical contrast, and bleached‐state transparency in a nickel oxide‐based electrochromic thin film. This work opens up new opportunities to enhance the functionalities of thin‐film devices by solid‐state conversion reactions.     

Broad distribution of enterotoxin genes (hblCDA, nheABC, cytK, and entFM) among Bacillus thuringiensis and Bacillus cereus as shown by novel primers

Eight new pairs of PCR primers were designed and efficiently detect eight toxin genes (hblC, hblD, hblA, nheA, nheB, nheC, cytK, and entFM) in 411 B. cereus strains (121 food- and 290 soil isolates) and 205 B. thuringiensis strains (43 serovars, 10 food- and 152 soil isolates). According to the presence of these eight toxin genes, they were divided into four groups among the total 616 isolates. In Group I, all eight genes occurred simultaneously in 403 (65.42%) isolates, while Group II (134 isolates or 21.75%) and Group III (46 isolates or 7.47%) were devoid of hblCDA and cytK, respectively. In Group IV, there were thirty-three isolates which lacked both hblCDA and cytK. The presence of hblCDA in B. thuringiensis strains (86.80%) was significantly higher (P<0.05) than in B. cereus strains (66.18%) whereas no significant difference in nheABC, cytK and entFM occurrence was detected between both bacterial groups. Both nheABC and entFM genes were found in all B. cereus and B. thuringiensis strains (616 strains in total), while the cytK gene could be detected in 365 (88.80%) of the B. cereus and 172 (83.90%) of the B. thuringiensis strains. None of the 616 tested strains showed the presence of only a single or two genes in either the hbl or nhe operons. The eight primer pairs designed for this multiplex PCR allowed rapid detection of eight toxin genes from boiled cells with high sensitivity, gave 100% reproducibility, and did not cross-react to 32 other bacterial strains.     

Pineapple leaf fibers (PALF) as the sustainable carbon anode material for lithium-ion batteries

Journal of Materials Science: Materials in Electronics - Pineapple leaf fiber (PALF) is considered as a promising low cost carbon precursor to produce a high graphitic carbon material, regarding to...     

Homogeneous polymer/filler composite membrane by spraying method for enhanced direct methanol fuel cell performance

In this work, composite membranes for a direct methanol fuel cell (DMFC) were prepared using a spraying method to improve cell performance especially at a high methanol concentration. Nafion polymer and mordenite as a filler were used for the composite membrane preparation using a spraying method and a conventional solution casting method and the membranes from the two methods were compared. SEM images showed that a more homogeneous composite membrane could be obtained using the spraying method. The effect of mordenite content was also studied. The membranes were consequently characterized and tested in DMFC operation. The results were compared to those prepared using the solution casting method at 30, 50, and 70 °C with methanol concentrations of 2, 4, and 8 M. It was found that the membrane with 5 wt.% mordenite from the spraying method showed a vast improvement in DMFC performance. When the cell was operated at 70 °C, the maximum power density of 5 wt.% mordenite from the spraying method was higher than that of commercial membrane and 5 wt.% from the solution casting method. Power densities from the 5 wt.% sprayed membrane were higher by around 29%, 40%, and 60% at 2, 4, and 8 M methanol concentration, respectively.     

Detailed microkinetic modelling of syngas to hydrocarbons via Fischer Tropsch synthesis over cobalt catalyst

Fuels production from syngas via Fischer Tropsch synthesis (FTs) is an alternative technology for clean energy production. The microkinetic model is a promising approach for gaining insight into FTs activity. In this study, a systematic microkinetic model was proposed to develop a process for cobalt-catalyzed FTs. All possible elementary reactions based on the carbide mechanism and characteristics of catalyst sites were considered in the kinetic model. The effects of the reaction rate constant, reaction pathways, and H₂ to CO ratio were represented by a kinetic parameter, reaction path, and operating parameter, respectively. The model could accurately predict product distribution trends, with an R² value and mean absolute relative residuals percentage of 0.91–0.93 and 5–43%, respectively, in comparison with experimental data. Hydrogen utilization was predicted and analyzed. High model accuracy was achieved, with a 10^?10–10^?3% error in the material balance.     

Low-temperature ozone exposure technique to modulate the stoichiometry of WOx nanorods and optimize the electrochromic performance

A low-temperature ozone exposure technique was employed for the post-treatment of WO(x) nanorod thin films fabricated from hot-wire chemical vapor deposition (HWCVD) and ultrasonic spray deposition (USD) techniques. The resulting films were characterized with x-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, UV-vis-NIR spectroscopy and x-ray photoelectron spectroscopy (XPS). The stoichiometry and surface crystallinity of the WO(x) thin films were subsequently modulated upon ozone exposure and thermal annealing without particle growth. The electrochromic performance was studied in a LiClO(4)-propylene carbonate electrolyte, and the results suggest that the low-temperature ozone exposure technique is superior to the traditional high-temperature thermal annealing (employed to more fully oxidize the WO(x)). The optical modulation at 670?nm was improved from 35% for the as-deposited film to 57% for the film after ozone exposure at 150?°C. The coloration efficiency was improved and the switching speed to the darkened state was significantly accelerated from 18.0?s for the as-deposited film to 11.8?s for the film after the ozone exposure. The process opens an avenue for low-temperature and cost-effective manufacturing of electrochromic films, especially on flexible polymer substrates.     

Glycidyl methacrylate grafted natural rubber: Synthesis,characterization, and mechanical property

Glycidyl methacrylate (GMA) was grafted onto natural rubber (NR) using emulsion polymerization method. The structures of copolymers were characterized by ¹H nuclear magnetic resonance (¹H‐NMR), solid state ¹³C‐NMR spectroscopy, and Fourier transform infrared spectrometer (FTIR). The %grafting obtained from the gravimetric method and the absorbance ratio were compared. Effects of reaction temperature, GMA content, and reaction time on %grafting, grafting efficiency, and %conversion of GMA monomer were determined. Effect of %grafting on mechanical properties of the graft copolymer was studied. Experimental result showed that the appropriate reaction time was 8 h at a reaction temperature of 30°C. Moreover, tensile strength and modulus of the graft copolymer increased with increasing %grafting. However, elongation at break of the graft copolymer decreased with increasing %grafting. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122: 3152–3159, 2011