Nanosized ZrO2 clusters were prepared by electrospinning a poly(vinylpyrrodine) (PVP)/ZrO2 mixture for calcination to remove PVP template and sizing. The morphological, chemical, structural, and thermal resistance changes during preparation stages were investigated using scanning electron microscope, energy-dispersive X-ray spectroscopy, transmission electron microscope, X-ray diffraction, and thermogravimetric analysis. The obtained ZrO2 clusters were used for preparation of nanocomposite membranes by dispersion in 2,6-pyridine polybenzimidazole (2,6-Py-PBI) matrix at 5?wt% content followed by phosphoric acid (PA) doping. The ZrO2 nanoclusters were found to be uniformly distributed in 2,6-Py-PBI/PA matrix leading to a remarkable increase in the PA doping level and proton conductivity of the obtained composite membrane. 相似文献
Analytical methods for molecular characterization of diagnostic or therapeutic targets have recently gained high interest. This review summarizes the combination of mass spectrometry and surface plasmon resonance (SPR) biosensor analysis for identification and affinity determination of protein interactions with antibodies and DNA-aptamers. The binding constant (KD) of a protein–antibody complex is first determined by immobilizing an antibody or DNA-aptamer on an SPR chip. A proteolytic peptide mixture is then applied to the chip, and following removal of unbound material by washing, the epitope(s) peptide(s) are eluted and identified by MALDI-MS. The SPR-MS combination was applied to a wide range of affinity pairs. Distinct epitope peptides were identified for the cardiac biomarker myoglobin (MG) both from monoclonal and polyclonal antibodies, and binding constants determined for equine and human MG provided molecular assessment of cross immunoreactivities. Mass spectrometric epitope identifications were obtained for linear, as well as for assembled (“conformational”) antibody epitopes, e.g., for the polypeptide chemokine Interleukin-8. Immobilization using protein G substantially improved surface fixation and antibody stabilities for epitope identification and affinity determination. Moreover, epitopes were successfully determined for polyclonal antibodies from biological material, such as from patient antisera upon enzyme replacement therapy of lysosomal diseases. The SPR-MS combination was also successfully applied to identify linear and assembled epitopes for DNA–aptamer interaction complexes of the tumor diagnostic protein C-Met. In summary, the SPR-MS combination has been established as a powerful molecular tool for identification of protein interaction epitopes. 相似文献
Toughness is an important property for being used in steels in engineering applications. In this research, tensile toughness of 45WCrV7 steel was measured and calculated in 10 different processing conditions. The results of tensile test showed that two samples had maximum tensile toughness. Microstructural studies demonstrated that the required condition for high tensile toughness was simultaneous increase in two microstructural factors named content and population density of the secondary carbides because a matrix which was poor of carbon and alloying elements was softened and thus increased total tensile toughness. 相似文献
Designing a spectrally efficient wireless channel requires a comprehensive understanding of its time and frequency varying characteristics, making it a stochastic medium of communication. These characteristics become more challenging to cater at the receiving terminal in a multipath transmission. This is because of the fading effect and Doppler shift of the transmitted frequency, specifically in cellular mobile radio systems and vehicle to vehicle communications. This paper presents the modeling, simulation, and then characterization of a cellular mobile radio multipath channel over its time and frequency varying fading gain. For this purpose, a discrete-time Finite Impulse Response (FIR) type filter of such a channel is designed, modeled, and simulated using time and frequency varying characteristics of the received signal. The simulated channel response is further analyzed in terms of coherence bandwidth, coherence time, delay spread, Doppler spread, and symbol time.
Multimodal imaging provides complimentary information that is advantageous in studying both cellular and molecular mechanisms in vivo, which has tremendous potential in pre‐clinical research and clinical translational imaging. It is desirable to design probes for multimodal imaging that can be administered minimally but provides multifaceted information. Herein, we demonstrate the complementary dual functional ability of a nanoconstruct for molecular imaging in both photoacoustic (PA) and surface‐enhanced Raman scattering (SERS) biosensing simultaneously in tandem. To realize this, a group of NIR active organic molecules are designed and synthesized that possess both SERS and PA activity. Nanoconstructs realized by anchoring such molecules onto gold nanoparticles are demonstrated for targeting cancer biomarkers in vivo while providing complimentary information about biodistribution and targeting efficiency. In future, such nanoconstructs could play a major role in identifying surgical margins and also for disease monitoring in translational medicine. 相似文献
The keys factor in making wind power one of the main power sources to meet the world’s growing energy demands
is the reliability improvement of wind turbines (WTs). However, the eventuality of fault occurrence on WT com
ponents cannot be avoided, especially for doubly-fed induction generator (DFIG) based WTs, which are operating
in severe environments. The maintenance need increases due to unexpected faults, which in turn leads to higher
operating cost and poor reliability. Extensive investigation into DFIG internal fault detection techniques has been
carried out in the last decade. This paper presents a detailed review of these techniques. It discusses the methods that
can be used to detect internal electrical faults in a DFIG stator, rotor, or both. A novel sorting technique is presented
which takes into consideration different parameters such as fault location, detection technique, and DFIG modelling.
The main mathematical representation used to detect these faults is presented to allow an easier and faster under
standing of each method. In addition, a comparison is carried out in every section to illustrate the main differences,
advantages, and disadvantages of every method and/or model. Some real monitoring systems available in the market
are presented. Finally, recommendations for the challenges, future work, and main gaps in the field of internal faults
in a DFIG are presented. This review is organized in a tutorial manner, to be an effective guide for future research for
enhancing the reliability of DFIG-based WTs. 相似文献
Bulletin of Engineering Geology and the Environment - Kandovan is one of the geo-tourism attractions in the East Azarbaijan Province of Iran, where rural houses were carved within the cone-shaped... 相似文献