The scope of the present work was to investigate and evaluate the electrochemical activity of H2/O2 fuel cells based on the influence of a heteropolyacid glass membrane with a Pt/C electrode at low temperature. A new trend of sol-gel derived PMA (H3PMo12O40) heteropolyacid-containing glass membranes inherent of a high proton conductivity and mechanical stability, was heat treated at 600 °C and implemented to H2/O2 fuel cell activities through electrochemical characterization. Significant research has been focused on the development of H2/O2 fuel cells using optimization of heteropolyacid glasses as electrolytes with Pt/C electrodes at 30 °C. A maximum power density of 23.9 mW/cm2 was attained for operation with hydrogen and oxygen, respectively, at 30 °C and 30% humidity with the PMA glass membranes (4-92-4 mol%). Impedance spectroscopy measurements were performed on a total ohmic cell resistance of a membrane-electrode-assembly (MEA) at the end of the experiment. 相似文献
Mobile adhoc networks consists of large number of mobile nodes, and is usually deployed to transfer data from a sender to a receiver using multi-hop routing. The data being transmitted may contain sensitive information, and undesired disclosure of information can lead to launching of various attacks, thus breaching the data privacy. Earlier works achieve data privacy by using approaches such as data transformation and data perturbation. However, these approaches introduce higher overheads and delays. We propose a computational intelligence based data privacy preserving scheme, where rough set theory is used to anonymize the data during data transfer. Data packets are enclosed within capsules that can be opened only by the designated node, thus preventing the undesired leakage of the data. Also, route between a sender and a receiver is changed dynamically by selecting more than one trusted 1-hop neighbor nodes in each routing step. The proposed data privacy preserving scheme is tested by considering different case studies in a MANET deployed for stock market. Theoretical analysis for data privacy is presented in terms of Information Gain by an attacker and Attacker Overhead, and the performance of proposed scheme against some of the attacks is also discussed. The simulation results show the effectiveness of proposed scheme.
The growth of hydroxyapatite (HAp) on physiologically clotted fibrin (PCF)-gold nanoparticles is presented for the first time by employing a wet precipitation method. Fourier transform infrared (FTIR) spectroscopy confirmed the characteristic functionalities of PCF and HAp in the PCF-Au-HAp nanocomposite. Scanning electron microscopy (SEM) images have shown cuboidal nanostructures having a size in the range of 70-300?nm of HAp, whereas 2-50?nm sized particles were visualized in high-resolution transmission electron microscopy (TEM). Energy-dispersive x-ray (EDX) and x-ray diffraction (XRD) studies have confirmed the presence of HAp. These results show that gold nanoparticles with PCF acted as a matrix for the growth of HAp, and that PCF-Au-HAp nanocomposite is expected to have better osteoinductive properties. 相似文献
The present work discusses the combined effect of High Density Polyethylene Homo polymer and Styrene-Butadiene-Styrene on properties of Viscosity Grade 30 asphalt commonly used in India. Six blends of binders were prepared using varying percentages of both polymers and were evaluated for rheological properties. Use of both polymers leads to higher viscosity, while blending with HDPH polymer only leads to marginal increase in viscosity when compared to unmodified binder. Comparison of dynamic modulus and phase angle master curves indicated, significant differences were found among master curves obtained with different aging conditions when compared to unaged condition especially at lower reduced frequencies. 相似文献
The phenological characteristics, oil content, and fatty acid composition of 34 selections of Cuphea procumbens have been studied. The mean seed yield per plant was 9.7 ± 0.43 g. Maximum seed yield (16.7 g) was noticed in NBC‐27, while the average number of fruits per plant was 124.9 ± 10.7. The oil content in the seeds ranged from 16.7—28.7%, maximum being in NBC‐34. The fatty acid composition revealed the presence of capric acid (C10:0) in all the selections of C. procumbens as the major constituent of the oil ranging from 87.7—94.6%. C. procumbens showed its novelty as an alternative source of capric acid and may be utilized as a renewable resource in the production of plasticizers and lubricants which wholly depend on petrochemical import. Researches are in progress in order to obtain tolerant cultivars against wild plant characteristics and some delayed seed shattering plants have been identified. 相似文献
Brain-Computer Interfaces (BCI) use Electroencephalography (EEG) signals recorded from the brain
scalp, which enable a communication between the human and the outside world. The present study
helps the patients who are people locked-in to manage their needs such as accessing of web url’s,
sending/receiving sms to/from mobile device, personalized music player, personalized movie player,
wheelchair control and home appliances control. In the proposed system, the user needs are designed
as a button in the form of a matrix, in which the main panel of rows and columns button is flashed in 3
sec intervals. Subjects were asked to choose the desired task/need from the main panel of the GUI by
blinking their eyes twice. The double eye blink signals extracted by using the bio-sensor of NeuroSky’s
mind wave device with portable EEG sensors are used as the command signal. Each task is designed
and implemented using a Matlab tool. The developed Personalized GUI application collaborated with
the EEG device accesses the user’s need. Once the system identifies the desired option through the
input control signal, the appropriate algorithm is called and performed. The users can also locate the
next required option within the matrix. Therefore, users can easily navigate through the GUI Model. A
list of personalized music, movies, books and web URL’s are preloaded in the database. Hence, it could
be suitable to assist disabled people to improve their quality of life. Analysis of variance (ANOVA) is also
carried out to find out the significant signals influencing a user’s need in order to improve the motion
characteristics of the brain computer interface based system. 相似文献
Development of low temperature fuel cells that operate under 100 °C are needed to reduce the costs, to design a class of hybrid membranes and to construct various structures of membrane-electrode-assembles (MEAs) for proton exchange membrane fuel cells (PEMFC). In this work, PVA/PMA/SiO2 hybrid composite membranes were synthesized and their conductivities were determined by impedance measurements. We found a maximum conductivity value of 4.2 × 10−3 S/cm at 80 °C and 100% relative humidity (RH). A fuel cell test evaluation for various MEAs was conducted by the potentiodynamic analysis and the current density values were determined from the current–voltage (I–V) curves. A maximum current density of 635 mA/cm2 was obtained at 80 °C and 100% RH. To the best of our knowledge, this is the first time that a high current density of PVA-based electrolytes for PEMFCs operating at low temperature is reported. The structural characters were examined using of XRD and FTIR methods, and thermal properties were studied using DSC and TGA techniques and the results were discussed (cf. supplementation). The present study revealed that the single cell performance depends mainly on the temperature, relative humidity and chemical compositions of the membranes. 相似文献
Enterohemorrhagic E. coil (EHEC) serotype O157:H7 is one of the major pathogens, responsible for the severe disease outbreaks. EHEC causes diseases in humans through production of shiga-like toxin leading to bloody diarrhea. The toxin is encoded by stx2 gene in E. coli. The current methodology for detection of EHEC relies on fluorogenic-substrate based culture media or nucleic acid amplification based Real-Time Polymerase Chain Reaction assays that are either time consuming or need expensive instrumentation. In this study, the optical properties of gold nanoparticles (GNPs) have been exploited for detection of nucleic acid of Escherichia coli O157:H7. The stx2 gene representing EHEC signature has been targeted using the gold nanoparticle probes. Gold nanoparticles (GNPs) of 20 +/- 0.2 nm were synthesised by citrate reduction method and characterised by spectroscopy and transmission electron microscopy. The GNPs were functionalised with 19 and 22 bp of thiolated single stranded DNA complementary to target highly conserved 149 bp region of stx2 gene. Transmission Electron Microscopy revealed the hybridization, aggregation and reduction in the interparticle distances of the GNP probes in the presence of target DNA. The aggregation and the spectral shift in the plasmon band observed with 10(6) copies of target DNA indicates feasibility of a simple and quick colorimetric 'spot and read' test in contrast to amplification based detection methods. 相似文献
Thin films of Cu2ZnSnS4 have been deposited by solution growth dip coating method. Different Cu/Zn/Sn/S molar ratios were applied, which tells the properties of copper, Zinc, Tin, and Sulfide using X-ray diffraction, UV–vis, Energy dispersive X-ray spectroscopy, and scanning electron spectroscopy. The pure CZTS thin film showed the phase transformation from Kesterite (tetragonal) to Kesterite (orthorhombic) crystal structure. Optical measurement analysis reveals that layers have relatively high absorption coefficient in the visible spectrum with a band gap reduction of 1.51–1.49?eV with an increase in the annealing temperature from room temperature to 300?°C for 1?h in hot air furnace without any presence of an inert gas. Optical conductivity was observed to increase from 1012 to 1013 (sec)?1 and electrical conductivity was of the order of 102 (Ω?cm)?1. 相似文献