Oxidative desulfurization using graphene and its composites for fuel containing thiophene and its derivatives: An update review

Oxidative desulfurization, in which the aromatic sulfur containing compounds are oxidized to their analogical sulfones and subsequently extracted, has assured to be one of the exceedingly effective desulfurization processes for resulting ultra-low sulfur import fuels. The oxidative desulfurization process using graphene oxide has attracted significant interest for sulfur removal from fuels. In this survey, we discussed systematically the techniques of desulfurizations in catalytic oxidation, including the role of graphene as a supported catalyst, the research results of oxidative desulfurization using graphene oxide and provided the factors affecting the desulfurization process. We also debate the challenges counterattack the use of graphene oxide in this view, including their preparation methods and their efficiency and stability as a supported catalyst. Also, there are some of the desulfurization processes currently under investigation such as oxidation, biodesulfurization, and adsorption was outlined in brief. The combustion of fossil fuels containing sulfur compounds emits some of the sulfur oxides which considered a harmful influence on human health and the surrounding environment as well as the economy. It can be concluded that GO remains a kind of ideal supported catalysts to recognize a pure fuel in the near futurity due to their eligible physicochemical characteristics.     

Metallurgical assessment of critical defects in continuous hot dip galvanized steel sheets

Development of hot dip zinc coated sheets in new applications increased demand for production of high quality galvanized coatings, but the presence of surface defects reduces the quality of these products. In order to alleviate the problem, one needs to know the extent to which the properties of a galvanized sheet are influenced by the presence of a given defect. In this paper, specimens including any of the four major defects of continuously galvanized steel sheets produced in an industrial continuous process have been studied. The defects, including scratches, bare spots, pimples and wrinkle bands, were microstructurally characterized and their influence on corrosion behavior of the coated sheet was evaluated. The defects, originating from insufficient cleaning procedure, improper quality of steel substrate or adhered metallic particles to the substrate surface, exert their main effects on corrosion resistance and surface quality. Corrosion behavior was examined via standard salt spray test and polarization test. Based on the experimental results, it was concluded that the corrosion resistance was influenced by severity of defects; bare spots reduced the overall corrosion resistance of galvanized sheet by 39% ± 1% and pimples by 10% ± 1% as compared to defect free specimens.     

Ciprofloxacin Liposomes as Vesicular Reservoirs for Ocular Delivery: Formulation,Optimization, and In Vitro Characterization

Management of extraocular diseases is mainly limited by the inability to provide long-term drug delivery without avoiding the systemic drug exposure and/or affecting the intraocular structures and poor availability of drugs, which may be overcome by prolonging the contact time with the ocular system, for instance with liposomes. Development and optimization of reverse phase evaporation ciprofloxacin (CPF) HCl liposomes for ocular drug delivery was carried out using a 2⁵ full factorial design based on five independent variables. The effects of the studied parameters on drug entrapment efficiency (EE), particle size, and percentage of drug released after 1 and 10 h were investigated. The results obtained pointed out that the molar concentration of cholesterol was the predominant factor that increased the EE% of the drug and the particle size responses. The percentage of drug released after 1 h was significantly controlled by the initial CPF concentration while that after 10 h was controlled by molar cholesterol concentration. The designed liposomes had average particle sizes that ranged from 2.5 to 7.23 μm. In addition, liposomes revealed a fast release during the first hour followed by a more gradual drug release during the 24-h period according to Higuchi diffusion model.     

Photovoltaic Properties and Negative Capacitance Spectroscopy of PCBM:P3HT/FTO Nanostructured Counter Electrode for TiO2-Based DSSC

Nano-clusters blind films of phenyl C61-butyric acid methyl ester (PCBM) and poly(3-hexylthiophene) (P3HT) were deposited on fluorine doped tin-oxide (FTO) substrate by spin coating and applied as counter electrodes instead of platinum for a new FTO/TiO₂?+?K30 dye-sensitized solar cell. The photovoltaic parameters of the fabricated solar cell; open circuit voltage, short circuit current, output power and fill factor, were studied under various light intensities in the range 20:110?mW?cm^?2. An impedance spectroscopy study was also performed in a wide frequency range (5?kHz–1?MHz) to study the electron transport properties of the solar cells. The capacitance–voltage of the prepared DSSC is characterized by two parts: positive values of capacitance at low frequency range, f?≤?100?kHz and negative capacitance i.e., an inductive behavior, in higher frequency range f?≥ 300 kHz Conducting polymer electrode based on PCBM:P3HT/FTO can be used as a counter electrode in a DSSC.     

An energy-aware distributed clustering protocol in wireless sensor networks using fuzzy logic

Clustering is an effective approach for organizing a network into a connected hierarchy, load balancing, and prolonging the network lifetime. On the other hand, fuzzy logic is capable of wisely blending different parameters. This paper proposes an energy-aware distributed dynamic clustering protocol (ECPF) which applies three techniques: (1) non-probabilistic cluster head (CH) elections, (2) fuzzy logic, and (3) on demand clustering. The remaining energy of the nodes is the primary parameter for electing tentative CHs via a non-probabilistic fashion. A non-probabilistic CH election is implemented by introducing a delay inversely proportional to the residual energy of each node. Therefore, tentative CHs are selected based on their remaining energy. In addition, fuzzy logic is employed to evaluate the fitness (cost) of a node in order to choose a final CH from the set of neighboring tentative CHs. On the other hand, every regular (non CH) node elects to connect to the CH with the least fuzzy cost in its neighborhood. Besides, in ECPF, CH elections are performed sporadically (in contrast to performing it every round). Simulation results demonstrate that our approach performs better than well known protocols (LEACH, HEED, and CHEF) in terms of extending network lifetime and saving energy.     

Structural health monitoring using extremely compressed data through deep learning

This study introduces a novel convolutional neural network (CNN)‐based approach for structural health monitoring (SHM) that exploits a form of measured compressed response data through transfer learning (TL)‐based techniques. The implementation of the proposed methodology allows damage identification and localization within a realistic large‐scale system. To validate the proposed method, first, a well‐known benchmark model is numerically simulated. Using acceleration response histories, as well as compressed response data in terms of discrete histograms, CNN models are trained, and the robustness of the CNN architectures is evaluated. Finally, pretrained CNNs are fine‐tuned to be adaptable for three‐parameter, extremely compressed response data, based on the response mean, standard deviation, and a scale factor. The performance of each CNN implementation is assessed using training accuracy histories as well as confusion matrices, along with other performance metrics. In addition to the numerical study, the performance of the proposed method is demonstrated using experimental vibration response data for verification and validation. The results indicate that deep TL can be implemented effectively for SHM of similar structural systems with different types of sensors.     

The antimicrobial,mechanical, physical and structural properties of chitosan–gallic acid films

Chitosan films incorporated with various concentrations of gallic acid were prepared and investigated for antimicrobial, mechanical, physical and structural properties. Four bacterial strains that commonly contaminate food products were chosen as target bacteria to evaluate the antimicrobial activity of the prepared gallic acid–chitosan films. The incorporation of gallic acid significantly increased the antimicrobial activities of the films against Escherichia coli, Salmonella typhimurium, Listeria innocua and Bacillus subtilis. Chitosan films incorporated with 1.5 g/100 g gallic acid showed the strongest antimicrobial activity. It was also found that tensile strength (TS) of chitosan film was significantly increased when incorporating 0.5 g/100 g gallic acid. Inclusion of 0.5 g/100 g gallic acid also significantly decreased water vapor permeability (WVP) and oxygen permeability (OP). Microstructure of the films was investigated by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) and it was found that gallic acid was dispersed homogenously into the chitosan matrix.     

Reformulated gasoline: Cleaner air on the road to nowhere

U.S. legislation taking effect in 1995 and requiring the sale of cleaner reformulated gasoline in heavily polluted areas provides limited environmental benefits, but it fails to take into account the world's dwindling reserves of oil, the eroding economics of using oil, and the political and military costs of maintaining access to non-domestic supplies. In contrast, natural gas offers greater emissions reductions than reformulated gasoline, at lower fuel costs and with greater domestic supply and energy security. In the long term, the expansion of the infrastructure that would support natural gas vehicles could facilitate the transition to hydrogen which, when produced from renewable resources, could become the optimum fuel for a sustainable transportation energy economy.