Co‐filled composites of micro magnesium dihydrate (MDH) and hydrophobically treated nano aluminum nitride (nH‐AlN) fillers in high temperature vulcanizing silicone gum are studied for thermal and ...dielectric characteristics for use as an insulating material in high voltage applications. The study begins with description of the compounding protocol adopted, followed by spectroscopic and optical characterization. Fourier transform infrared spectroscopy (FTIR) and energy dispersive X‐ray spectroscopy (EDX) analysis are used to verify the presence of nH‐AlN and MDH in the composites. Thermal analysis through thermogravimetric analysis revealed a stark enhancement in the onset of polymer degradation temperature, with an improvement of 208 °C achieved at 30 phr by weight loading level of MDH. Volume resistivity of 9.71 E14 Ω‐cm is obtained at 30 phr weight loading of MDH and 5 phr of nH‐AlN. AC, +DC, and −DC dielectric strength improved by 1.09, 2.06, and 1.08 times for co‐filled composites at 30 phr MDH and 5 phr nH‐AlN loading levels over unitary filled composite. Effect of dielectric polarization on dielectric constant and dissipation factor is studied at various frequencies. Limitations while conducting dry arc resistance test at standard voltage of 12.50 kV is discussed, with modification in dry arc resistance test voltage to 16.95 kV. The results are presented and discussed here.
The study explores the use of micro magnesium dihydrate (MDH) and nano aluminum nitride (nH‐AlN) in developing silicone based co‐filled composites for high voltage insulation applications. A co‐filled composite with 5 phr nH‐AlN and 30 phr MDH is disclosed as the ideal composition offering superior thermal and dielectric properties.
In this paper, we discuss the effect of different terminal polar groups attached to biphenyl units of 2,3,4-trihydroxy benzonitrile-based trimers on the mesomorphic properties. The thermal properties ...of two new series namely 2,3,4-tris-ω-(4-fluorobiphenyl-4'-yloxy)alk-1-yloxybenzonitrile and 2,3,4-tris-ω-(biphenyl-4'-yloxy)alk-1-yloxybenzonitrile were compared with cyano-substituted analogous which was previously reported. Two new trimers, which are fluoro- and hydrogen-substituted compounds were synthesised by etherification of 4-fluoro-4'-(n-bromoalkane-1-yloxy)biphenyl or 4-(n-bromoalkane-1-yloxy)biphenyl with 2,3,4-trihydroxy benzonitrile under basic conditions. Polarising optical microscope and differential scanning calorimeter were used for the characterisation of mesogenic properties. The small- and wide-angle X-ray scattering (SAXS and WAXS) measurements show the formation of intercalated trimers in the nematic (N) phase. This study enables to understand the influence of terminal polar groups on the liquid crystalline behaviour of trimers in a non-conventional molecular design.
Passive antenna is applied in medical applications such as sensor, radiometer, rectenna, and implantable device for accurate measurement and analysis. Moreover, passive antennas can replace the ...optical sensors in the pathological instruments to overcome the drawbacks such as optical interference, offset voltage, time consumption and dark current. Furthermore, prothrombin time (PT) measurement through optical and mechanical instruments requires repeated testing for accurate results due to turbidity (lipemia) in blood Plasma and reagent sensitivity during coagulation. Plasma samples in instruments with more K vitamin influences the accuracy of PT measurements. In this paper, we propose a method to measure the PT from blood plasma through passive Ultra-Wideband sensor and overcomes the above problem. The proposed multilayer flexible substrate ultra-wide band (MFS-UWB) passive antenna absorbs the electromagnetic radiations from the concentration of plasma during clotting. The Concentration of plasma is proportional to electromagnetic energy density during clotting. The clotting duration time is acquired based on voltage. During clotting, observed electromagnetic emitted voltage is converted into frequency for measuring the clot concentration and the observed radiation from human blood clotting frequency ranges from 2GHz to 3GHz and voltage from 0.55mV to 0.85mV. The acquired blood clotting concentration voltage measures the prothrombin time using regression modelling and validated through laboratory values.
Lumber cerebrospinal fluid (CSF) concentrations of metabolites of noradrenaline, adrenaline and serotonin were estimated in patients of sustained hypertension (n = 20), and healthy controls (n = 15). ...Platelet uptake of serotonin and its basal contents were also estimated in the same individuals. CSF 5-hydroxy indole acetic acid level (5-HIAA) (major metabolite of serotonin) was significantly higher in hypertensives than controls (p less than .01). CSF 3-methoxy, 5-hydroxy phenyl glycol (MHPG) (major metabolite of adrenaline and noradrenaline) level was also raised significantly in cases of hypertension (p less than .01). However, platelet uptake of serotonin as well as its basal contents in hypertension were significantly lower than controls (p less than .01). It can thus be postulated that there exists an increased central serotonergic and catecholaminergic activity in hypertension. Furthermore, alterations observed in platelet serotonin uptake and its basal content suggest the involvement of platelet serotonergic system in hypertension.
The dielectric spectra of the twist bend nematic phase (N_{TB}) of an achiral asymmetric bent-core liquid crystalline compound are studied for determining the various relaxation modes. Dielectric ...measurements are also carried out under the bias field E up to 8 V/µm. Two molecular and two collective relaxation processes are observed. The orientational order parameters with respect to the local and the main directors determined using molecular modes are used to find the heliconical angle. The results also show that the order parameter with reference to the main director reverses its trend from increasing to decreasing at temperatures of a few degrees above the N_{TB} to N transition. The collective relaxation modes are assigned to (a) distortions of the local director by the electric field at a frequency of ∼100kHz while the periodic helical structure remains unaltered (mode attributed to flexoelectricity); (b) changes in the periodic structure arising from a coupling of the dielectric anisotropy with the electric field at the lowest frequency in the range of 100 Hz-10 kHz. Frequency of the higher frequency collective mode (∼100kHz) depends primarily on the heliconical angle and has anomalous softeninglike behavior at the N-N_{TB} transition. The lowest frequency mode is studied under the bias field E; the modulus of the wave vector gradually vanishes on increasing E (except for an initial behavior, E^{2}<0.1V^{2}/μm^{2}, which is just the opposite). The transition from the twist bend to splay bend structure is observed by a sudden drop in the frequency of this mode, followed by a linear decrease in frequency by increasing E. The results agree with the predictions made from the currently proposed models for a periodically distorted N_{TB} phase.
Electromechanical impedance (EMI) technique is amongst the important technique in structural health monitoring field. Incipient level of damage can easily be detected through this technique as ...compared to other. Various PZT sensor configurations were proposed by the researcher for the EMI technique, which have their own advantages and disadvantages. In this paper surface bonded PZT sensor (SBPS) and surface mounted PZT sensor (SMPS) are used in steel I-section beam. Damages are induced in the beam and damage quantification is done using statistical tool. On comparing it was found that SMPS has more sensing region than SBPS. It is due to absence of shear lag effect in SMPS, which is not in the case of SBPS. The shear lag affects the strain transfer mechanism between the PZT sensor and host structure. The sensing region of SMPS is upto 3.5 m whereas the sensing region of SBPS is less than 2.0 m in the case of steel beam.
The features of mobile devices are being continuously upgraded to provide quality of services to the mobile user seeking location-based information by allowing the usage of context-aware data. To ...protect an individual’s location & his information to untrusted entity, a multi-level caching, i.e., Mobility Aware Data Replacement & Prefetching Policy Enrooted LBS using spatial k-anonymity (MAD-RAPPEL) is being proposed in this paper. It enhances user privacy by forming the cloaking region in cache replacement and prefetching. The cache replacement and invalidation module uses the next location prediction algorithm by the application of the mobility Markov model on mobile user’s trajectories. The client-server queuing model is used to simulate the system for the experimentation to see the performance of MAD-RAPPEL. The results obtained through the simulation demonstrate that the proposed MAD-RAPPEL minimizes the overhead of the LBS as compared to already existing prior LBSs.
Among the neglected tropical diseases, leishmaniasis continues to be prevalent in many tropical and subtropical countries despite international, national, and local efforts towards its control and ...elimination over the last decade. This warrants a critical evaluation of such factors as under-reporting, asymptomatic infections, post kala azar dermal leishmaniasis (PKDL) cases, and drug resistance. In this review, we highlight lesser-understood atypical presentations of the disease involving atypical parasite strains against a background of classical leishmaniasis with a focus on the Indian subcontinent.
A literature review based on endemic areas, the nature of disease manifestation, and underlying causative parasite was performed with data collected from WHO reports for each country. Searches on PubMed included the term ''leishmaniasis" and "leishmaniasis epidemiology" alone and in combination with each of the endemic countries, Leishmania species, cutaneous, visceral, endemic, non-endemic, typical, classical, atypical, and unusual with no date limit and published in English up to September 2017. Our findings portray a scenario with a wider distribution of the disease in new endemic foci, with new discoveries of parasite-driven atypical disease manifestations in different regions of the world. Unlike the classical picture, some Leishmania species are associated with more than one disease presentation, e.g., the L. donovani complex, generally associated with the visceral form, is now also associated with a cutaneous disease presentation, while L. tropica species complex, known to cause cutaneous disease, can cause viscerotropic disease. This phenomenon points towards the discovery of novel parasite variants as etiologic agents of atypical disease manifestations and represents an excellent opportunity to identify and study genes that control disease virulence and tropism.
The increased recognition of atypical leishmaniasis as an outcome of parasite variants has major implications for leishmaniasis control and elimination. Identifying molecular correlates of parasite isolates from distinct regions associated with different disease phenotypes is required to understand the current epidemiology of leishmaniasis in regions with atypical disease.
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