Physical and tensile properties of epoxy laminated magnetic bacterial cellulose nanocomposite films

Despite many potential applications, the adverse impacts of magnetic nanoparticles on the tensile properties of magnetic cellulose papers and films are well established. On the other hand, water absorption and thickness swelling of cellulose materials are important limiting factors in many engineering applications. These challenges caused limited applications of magnetic cellulose nanocomposites. The aim of this study is to examine the possibility of modifying the physical and mechanical behaviors of magnetic bacterial cellulose films by epoxy resin lamination. Results showed that the tensile modulus and strength of the magnetic bacterial cellulose film, respectively, increased about 280% and 240% after epoxy lamination while they maintained their desirable magnetic and flexibility properties. Furthermore, the water absorption and thickness swelling of the epoxy laminated magnetic nanocomposite films, respectively, improved about 43% and 42%. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45118.     

Partial oxidation of13C-labeled ethylene in methane over Ca/Ni/K catalysts

The relative reactivity of ethane and ethylene compared to methane over the Ca/Ni/K catalyst was determined. The reactivities are in the order of ethylene > ethane methane. The catalyst was also studied using temperature-programmed reaction, desorption and decomposition.     

Multi-Hop WiMAX Networks: A New Opportunistic Algorithm Using AMC and PUSC Mode for Different Mobility Users

Resource allocation algorithms play the main role in provisioning high throughput in broad band wireless communications. The previous studies in WiMAX networks have considered either AMC or PUSC techniques for the resource allocation algorithms. In this way, AMC based algorithms have presented high throughput for low speed users. Conversely, PUSC based algorithms have not been affected by users’ speed, whilst the throughput is low. To date, the importance of presenting proportional fair and maintaining the network throughput for the users with different speeds has not been acknowledged yet. This paper presents a novel opportunistic algorithm which is suitable for the users with different mobility speeds. The new algorithm uses two modes of AMC and PUSC simultaneously. The simulation results reveal that in comparison to similar algorithms, the proposed algorithm presents more proportional fair throughput when there are both high and low speed users.     

Effects of nozzle arrangement angle on the performance of partially admitted turbines

Journal of Mechanical Science and Technology - This paper presents the experimental and numerical evaluations of the effects of a supersonic Nozzle arrangement angle (NAA) on the performance of an...     

Using almond (Prunus amygdalus L.) shell as a bio-waste resource in wood based composite

In this research, the suitability of almond shell as a bio-waste resource in wood based composite manufacturing was investigated. Particleboards containing different almond shell particle rations were made using urea–formaldehyde (UF) resin. Some chemical properties of almond shell (holocellulose, α cellulose, lignin and ash contents, alcohol–benzene solubility, 1% NaOH solubility, hot and cold water solubility), mechanical (modulus of rupture, modulus of elasticity and internal bond strength) and physical properties (thickness swelling and water absorption) of the particleboards were determined. The addition of almond shell particles greatly improved the water resistance of the panels. However, flexural properties and internal bond strength decreased with increasing almond shell particle content. The amount of almond shell particles at most should be 30% in the mixture to meet the standard required for mechanical properties. Conclusively, almond shell, an annual agricultural residue, could be utilized with mixture of wood particles in the particleboard manufacturing.     

Effect of green GO/Au nanocomposite on in‐vitro amplification of human DNA

Recently nanomaterials have attracted interest for increasing efficiency of polymerase chain reaction (PCR) systems. Here, the authors report on the usefulness of green graphene oxide/gold (GO/Au) nanocomposites for enhancement of PCR reactions. In this study, green GO/Au nanocomposite was prepared with Matricaria chamomilla extract as reducing/capping agent for site‐directed nucleation of Au^o atoms on surface of GO sheets. The as‐prepared green GO/Au nanocomposites were then characterised with UV–VIS spectrophotometer and scanning electron microscopy. Later, the effect of these nanocomposites was studied on end‐point and real‐time PCR employed for amplification of human glyceraldehyde‐3‐phosphate dehydrogenase gene. The results indicated that GO/Au nanocomposite can improve both end‐point and real‐time PCR methods at the optimum concentrations, possibly through interaction between GO/Au nanocomposite and the materials in PCR reaction, and through providing increased thermal convection by the GO surface as well as the Au nanostructures. In conclusion, it can be suggested that green GO/Au nanocomposite is a biocompatible and eco‐friendly candidate as enhancer of in‐vitro molecular amplification strategies.Inspec keywords: graphene, molecular biophysics, nucleation, enzymes, gold, nanofabrication, nanocomposites, scanning electron microscopy, nanoparticles, DNA, nanomedicine, ultraviolet spectra, visible spectra, graphene compoundsOther keywords: green GO/Au nanocomposite, polymerase chain reaction systems, green graphene oxide/gold, PCR reaction, as‐prepared green GO/Au nanocomposites, real‐time PCR methods, Au nanostructures, in‐vitro amplification, human DNA, Matricaria chamomilla extract, site‐directed nucleation, Au, CO, CO‐Au     

Determination of lisinopril using β-cyclodextrin/graphene oxide-SO3H modified glassy carbon electrode

An electrochemical method has been successfully demonstrated for sensitive determination of lisinopril with β-cyclodextrin-graphene oxide-SO₃H composite modified glassy carbon electrode (β-CD/GO-SO₃H/GCE). Cyclic voltammetry, differential pulse voltammetry, and chronocoulometry were used to investigate the electrochemical behavior of lisinopril at β-CD/GO-SO₃H/GCE. The cyclic voltammetric results indicate that β-CD/GO-SO₃H/GCE can remarkably enhance electroactivity toward the oxidation of lisinopril in buffer solutions. The electrochemical behavior was further exploited as a sensitive detection scheme for the lisinopril determination by differential-pulse voltammetry. Under optimized conditions, the concentration range and detection limit were 0.21–190.4 and 0.11 µM (S/N = 3), respectively. The method was successfully applied to assay the drug in human serum.     

Carbon-Pt nanoparticles modified TiO2 nanotubes for simultaneous detection of dopamine and uric acid

The present work describes sensing application of modified TiO2 nanotubes having carbon-Pt nanoparticles for simultaneous detection of dopamine and uric acid. The TiO2 nanotubes electrode was prepared using anodizing method, followed by electrodeposition of Pt nanoparticles onto the tubes. Carbon was deposited by decomposition of polyethylene glycol in a tube furnace to improve the conductivity. The C-Pt-TiO2 nanotubes modified electrode was characterized by cyclic voltammetry and differential pulse voltammetry methods. The modified electrode displayed high sensitivity towards the oxidation of dopamine and uric acid in a phosphate buffer solution (pH 7.00). The electro-oxidation currents of dopamine and uric acid were linearly related to the concentration over a wide range of 3.5 x 10(-8) M to 1 x 10(-5) M and 1 x 10(-7) M to 3 x 10(-5) M respectively. The limit of detection was determined as 2 x 10(-10) M for dopamine at signal-to-noise ratio of 3. The interference of uric acid was also investigated. Electro-oxidation currents of dopamine in the presence of fix amount of uric acid represented a linear behaviour towards successive addition of dopamine in range of 1 x 10(-7) M to 1 x 10(-5) M. Furthermore, in a solution containing dopamine, uric acid and ascorbic acid the overlapped oxidation peaks of dopamine and ascorbic acid could be easily separated by using C-Pt-TiO2 nanotubes modified electrode.     

Dummy template molecularly imprinted polymer for omeprazole and the study of its drug binding and release properties

In this study, we tried to prepare an omeprazole (OMP)‐imprinted polymer and study its binding and release properties in an aqueous media. Because of the instability of OMP under polymerization conditions and the inability of the molecule to form effective interactions with monomers, pantoprazole (PANTO) was used as a dummy template for the imprinting process. Different monomers and solvents were evaluated in polymerization. The optimized imprinted polymer was prepared in chloroform as a porogen. Also, 4‐vinylpyridine and ethylene glycol dimethacrylate were selected as a functional monomer and a crosslinker, respectively. The optimized imprinted polymer was evaluated in a binding study. The binding and release properties of the polymer were then investigated at different pHs. Our data indicated a higher affinity of the imprinted polymer to PANTO and OMP than that of nonimprinted polymer (NIP). The maximum percentage of OMP released from the imprinted polymer was 36–41%, whereas that for the NIP was 74–85%. These data were related to the 38–43 and 29–34 μg of OMP released from the imprinted polymer and NIP, respectively. Also, the protective effect of the imprinted polymer for OMP at pH 2 was greater than that of the nonimprinted one. This study revealed that the dummy template molecular imprinting was an effective method for preparing selective imprinted cavities in a polymeric matrix, especially for the molecules that were unstable during polymerization or unable to establish effective bonds with the monomers. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4165–4170, 2013     

Scientometric analysis of the major Iranian medical universities

Nowadays, scientometrics has become an important field of study to monitor the progresses in scientific performance of a research group, a department, a university etc. A number of scientometrical studies have been done about Iranian scientific outcome in recent years. But there is no comparison between major Iranian medical universities. In this study, by using Scopus as search engine, the scientific outcomes of the Iran University of Medical Sciences, Isfahan University of Medical Sciences, Mashhad University of Medical Sciences, Shahid Beheshti University of Medical Sciences, Shiraz University of Medical Sciences, Tabriz University of Medical Sciences, and Tehran University of Medical Sciences have been compared with each other. These universities were compared by the number of published articles per year, number of citations received per year, number of citations received per year per article, total H-indices, top ten authors, and top ten journals. The results of this study show that the order of the studied universities in research performance is as follow: Tehran > Shiraz = Shahid Beheshti > Isfahan = Iran > Tabriz = Mashhad universities of medical sciences. In addition, the data of Tehran University of Medical Sciences as the top medical university of Iran was compared with some of top medical universities around the world.