Production of hydrogen by Enterobacter aerogenes in an immobilized cell reactor

The production of hydrogen from glucose by using Enterobacter aerogenes ATCC 13048 (E. aerogenes) in an immobilized cell reactor (ICR) was investigated. The effect of several factors, such as the glucose concentration, feed flow rate, and fermentation time were examined. The highest amount of hydrogen (9.44 mmol H₂/g glucose) was obtained at a glucose concentration of 8 g/L, flow rate of 0.5 mL/min, retention time of 24 h and at a temperature of 30 °C. Meanwhile, the highest amount of carbon dioxide (1.68 mmol CO₂/g glucose) was obtained at a glucose concentration of 10 g/L, flow rate of 0.7 mL/min, hydraulic retention time of 24 h and at a temperature of 30 °C. The hydrogen and carbon dioxide production were affected by glucose concentration, hydraulic retention time (HRT) and fermentation time. This study showed that the ICR was a very efficient method for the production of hydrogen and carbon dioxide gases.     

Review on fermentative biohydrogen production from water hyacinth,wheat straw and rice straw with focus on recent perspectives

Hydrogen (H₂) is often considered as the best option to store energy coming from renewable sources. Hydrogen production from lignocellulosic biomass via fermentation offers low cost and environmental friendly method in terms of energy balance and provides a sustainable pathway for utilization of huge amount of unused biomass. In this regard, special attention on potential of different lignocellulosic biomass is required. In this paper, the fermentative hydrogen production from three carbohydrates-rich biomass: water hyacinth, wheat straw and rice straw is comprehensively reviewed. In other point of view, usage of H₂ has a 10% growth annually that will reach to 8–10% of total energy in 2025. Furthermore, research on recent trends of fermentative hydrogen production is crucial and vital. However, the majority of the published researches in the last decade confirmed that some challenges exists which are the process optimization, effecting parameters and commercialization aspects.     

A methodology for the evaluation of the replacement of information network technology with applications

A methodology for the evaluation of the replacement of one network technology by another is presented here. The methodology is based on technical evaluations associated with the network capacity on the one hand, and an economic evaluation concerned with its services on the other. An application of the methodology to a case study shows that ATM should replace the available conventional packet switching over 64∼kbps digital technology immediately. Copyright © 2000 John Wiley & Sons, Ltd.     

A remote diagnosis of Parkinson's ailment using artificial intelligence based BPNN framework and cloud based storage architecture for securing data in cloud environment for the application of telecommunication technologies

Voice signal analysis and identification of disease framework for Parkinson's disease (PD) is most required thing in the past few years. A new framework for determination and identification of PD is the world's most severe neurological disorder, was proposed in this article. It is the most dangerous infection which disables individuals' discourse, and different attributes, for example feelings and sensation. In this work, we initially examined about a new approach for determining the PD. Second, we proposed cloud based storage architecture for securing data in cloud computing environment. Cloud based system for distinguishing and checking Parkinson infection will expand its significance in social insurance benefit in low asset setting and security examination. This structure guarantees effective handling of huge information in distributed computing condition and acquires business experiences. In the creating nations, where the greater part of the general population does not get appropriate social insurance benefits and are not concerned of Parkinson's sickness, not to mention recognizing and getting human services for PD, this framework can be extremely commonsense and helpful. The framework, PD affected patient can be effortlessly identified as well as analyzed by giving their voice tests over their telephones. The proposed frameworks are profited to accomplish 95.8% precision in the cloud condition for recognizing PD. It is normal that the proposed system will possibly empower social insurance benefit for PD patients, who live in remote territories.     

Rubberwood–polymer composites based on glycidyl methacrylate and diallyl phthalate

Wood–polymer composites (WPC) of rubberwood (Hevea Brasiliensis) were prepared by impregnating the wood with glycidyl methacrylate (GMA), combinations of glycidyl methacrylate and diallyl phthalate (GMA–DAP), or diallyl phthalate (DAP) alone. Polymerization was carried out by catalyst-heat treatment. The results showed that WPC based on GMA exhibited greater dimensional stability (results of antishrink efficiency after six days of soaking) about five times than those based on DAP alone. Flexural [Modulus of Elasticity (MOE), Modulus of Rupture (MOR), and toughnes], compressive, and impact properties for all the samples tested are improved, especially for those with higher chemical loading. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:1221–1226, 1998     

Studies of electrical properties of some fire-retarding poly(vinyl chloride) compositions

Several fire-resistant formulations were prepared from a sample of poly(vinyl chloride) (PVC), small variable proportions of chloroorganic adducts [1,2,3,4,7,7-hexachloro-5-carboxy,bicyclo(2,2,1)heptene-2] or [1,2,3,4,7,7-hexachloro-5-carboxy,5-methyl-bicyclo(2,2,1)heptene-2] as fire-retarding modifiers, plasticizers (dibutylphthalate and a chlorinated paraffin), and a heat stabilizer (dibutyltindilaurate). The fire-resistance and electrical properties of the obtained formulations were studied to obtain a fire-retarding plasticized PVC of good electrical insulation character. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 27–35, 1997     

Comparing Nanohydroxyapatite Graft and Other Bone Grafts in the Repair of Periodontal Infrabony Lesions: A Systematic Review and Meta-Analysis

Objective: To compare the results of periodontal infrabony lesions treated using nanohydroxyapatite (NcHA) graft with other bone grafts (BGs). Methods: Four electronic databases were searched including PubMed (NLM), Embase (Ovid), Medline, and Dentistry and Oral Sciences (EBSCO). The inclusion criteria included randomised controlled clinical trials (RCTs) and controlled clinical trials (CCTs). The clinical results of NcHA were compared with other BGs. For clinical attachment level (CAL) gain, probing pocket depth (PPD) decrease, and gingival recession (REC) change, weighted averages and forest plots were computed. Results: Seven RCTs fulfilled the selection criteria that were included. When NcHA was compared to other BGs, no clinically significant differences were found in terms of each outcome assessed, except the REC change for synthetic BGs as compared to NcHA. Conclusions: The use of an NcHA graft showed equivalent results compared to other types of BGs. To further validate these findings, future studies are required to compare the NcHA and various BGs over longer time periods and in furcation deficiencies.     

Defects and Disorder in Covalent Organic Frameworks for Advanced Applications

Crystalline porous organic polymers (CPPs) or covalent organic frameworks (COFs), are composed by light elements linked by covalent bonds. Despite the remarkable progress attained, there are still bottlenecks limiting further development, some of them related to the presence of defects during their synthesis as well as in-depth understanding of structure of active centers and/or details of the reaction mechanism. Indeed, very often the proposed structures are far from reality because defects and disorders have not been considered. The present review provides an illustrative overview of “defects and disorder in COFs”. These defects include those not only generated during the synthesis and manipulation of COFs, but also lack of crystallinity, stacking disorder and network vacancies. The review starts giving general remarks on organic COFs and their synthetic methods, followed by different methods to play and manage defects, how to minimize them or how to take advantage of them to gain new properties and applications. Selected characterization techniques to quantify defective structures and active sites in COFs are also presented. Finally, the challenges and future opportunities in the field have been summarized in the last section.     

Electrospun Nanoparticle–Nanofiber Composites via a One‐Step Synthesis

A facile approach to synthesize and incorporate metal nanoparticles (NPs) into electrospun polymer nanofibers (NFs) wherein the electrospinning polymer acts as both a reducing agent for the metal salt precursor, as well as a protecting and templating agent for the ensuing NPs, is reported. Such a true one‐step process at ambient conditions and free of organic solvents is demonstrated using a system comprising AgNO₃ and poly(ethylene oxide) (PEO) at electrospinnable molecular weights of 600, 1000, or 2000 kDa. The PEO transforms Ag⁺ into AgNPs, a phenomenon that has not been previously possible at PEO molecular weights less than 20 kDa without the addition of a separate reducing agent and stabilizer or the application of heat. Results from X‐ray photoelectron spectroscopy and UV–Vis absorption spectrophotometry analyses support the formation of pseudo‐crown ethers in high molecular weight PEO as the mechanism in the development of NPs. The AgNPs reduce fiber diameter and enhance fiber quality (reduced beading) due to increased electrical conductivity. Interestingly, several of the NFs exhibit AgNP‐localized nanochain formation and protrusion from the NF surface that can be attributed to the combined effect of applied electrical field on the polymer and the differences between the electrical conductivity and polarizability of the polymer and metal NPs.     

Improvement of white organic light emitting diode performances by an annealing process

White organic light emitting diode (OLED) devices with the structure ITO/PHF:rubrene/Al, in which PHF (poly(9,9-di-n-hexylfluorenyl-2,7-diyl)) is used as blue light emitting host and rubrene (5,6,11,12-tetraphenylnapthacene) as an orange dye dopant, have been fabricated. Indium tin oxide (ITO) coated-glass and aluminium were used as anode and cathode, respectively. The devices were fabricated with various rubrene-dopant to obtain a white light emission. The OLED device that composed of several concentrations of rubrene-doped PHF film was prepared in this study. It was found that the concentration of rubrene in the PHF-rubrene thin film matrix plays a key role in producing the white color emission. In a typical result, the device composed of 0.06 wt.% rubrene-dopant produced the white light emission with the Commission Internationale de L'Eclairage (CIE) coordinate of (0.30,0.33). The turn-on voltage and the brightness were found to be as low as 14.0 V and as high as 6540 cd/m², respectively. The annealing technique at relatively low temperature (50 °C, 100 °C, and 150 °C) was then used to optimize the performance of the device. In a typical result, the turn-on voltage of the device could be successfully reduced and the brightness could be increased using the annealing technique. At an optimum condition, for example, annealed at 150 °C, the turn-on voltage as low as 8.0 V and the brightness as high as 9040 cd/m² were obtained. The mechanism for the improvement of the device performance upon annealing will be discussed.