Dielectric behavior and structural characterization of polymeric double layer thin films

In the present work, various techniques have been employed to investigate the polarization processes along with the estimation of various parameters involved therein in polymethylmethacrylate (PMMA), polyvinylidenefluoride (PVDF), and PVDF-PMMA double-layered samples. Anticipating the difficulty to analyze the experimental data; in such complicated situation, when in one the same temperature range various decay mechanism may complete, the different techniques are used to interpret the experimental results. These measurements verify the various processes responsible polarization in these polymer samples. The structural morphology, crystallinity, atomic, and molecular geometry were analyzed using different characterization tools, namely SEM, XRD, FTIR, and DSC; therefore, the results were found to be in confirmation with amorphous nature of PMMA and semicrystalline nature of PVDF and PVDF-PMMA double-layered samples. Ac dielectric measurements were performed for different temperatures over the frequency range of 100 Hz to 10 kHz. Dielectric losses have also been recorded with a two terminal (Al-Al) electrode combination. The study revealed that both interfacial phenomena and space charge mechanism are known to play preliminary role in the dielectric behavior of double-layered samples. The amorphous–crystalline interface act as charge-carrier trapping sites in this polymeric heterogeneous system. Dielectric permittivity and dielectric loss of the double-layered sample depend manifolds on the temperature and the Ac frequency. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47724.     

Synthesis and physicochemical study of polyester polyols of epoxy resin of 2,4,6‐tris(4‐hydroxyphenyl)‐1,3,5‐triazine and their polyurethanes

Polyester polyols of ricinoleic acid (ETPRA), oleic acid, linoleic acid (ETPLA), and rosin (ETPR) and epoxy resin of 2,4,6‐tris(4‐hydroxyphenyl)‐1‐3‐5‐triazine (ETP) and their polyurethanes (PUs) were synthesized and characterized by Fourier transform infrared spectroscopy, NMR, differential scanning calorimetry, and thermogravimetric analysis techniques. The PU films showed the following density order: ETPRPU600 > ETPRAPU600 > ETPLAPU600. ETPLAPU600 showed good tensile strength and volume resistivity values compared to ETPRAPU600 and ETPRPU600. All three PUs showed good electric strength. ETPLAPU600 showed almost double the electric strength of ETPRAPU600 and ETPRPU600. The incorporation of soft‐segment poly(ethylene glycol) 600 into PU chains resulted in the flexibility of the films. The PU films showed a high water absorption tendency in water, acidic, and saline environments, and they degraded in an alkaline environment. The weight gain tendency of the films was due to surface solvolysis and was also probably due to microcrack formation. The polyester polyols and PUs were thermally stable up to about 167–221 and 184–214°C, respectively, and followed multistep degradation reactions with either fractional or integral order (0.43–2.71) degradation kinetics. Thus, the structure of the PUs affected the studied physicochemical properties of the films. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40203.     

Hypex: A Tool for Extracting Business Intelligence from Sentiment Analysis using Enhanced LSTM

Multimedia Tools and Applications - Sentiment analysis, an application of machine learning in business is the process of identifying and cataloging comments, reviews, tweets, feedback, and even...     

Time series analysis of co-polarization phase difference (PPD) for winter field crops using polarimetric C-band SAR data

The utility of time series polarimetric C-band data for vegetation state monitoring was explored to understand the mechanism of growth and phenology for important winter crops in India. Parameters investigated were HH–VV phase difference (co-polarization phase difference, PPD), amplitude ratio, and polarization indices. Data were acquired during the entire growth phase categorized as early, mid/peak vegetative, and post-vegetative /flowering phase. The trend emerging in this study showed a shift in the phase difference distribution for agricultural areas relating to the growth rate for various crops. The time series data set revealed that the PPD is a function of frequency and was directly affected by crop type (planophile or erectophile), vigour, structure, and crop biophysical parameters, particularly biomass. The behaviour of crop biomass with PPD responded differentially across crop architectures and vigour classes. Co-polarization index was found to be a good measure for discrimination in early growth stages while cross-polarization index suited in advanced vegetative stages where geometrical orientation was uniform. The PPD captured the change in frequency distribution resulting in a peaked distribution at sowing changing to smooth, well-spread frequency distribution as the peak vegetation stage approaches. This histogram nature is observed to be gradual for high-biomass crops and peaked in case of the low-biomass crops. It is indicative of the rate of growth; a low peaked normal curve indicates faster growth rate and resulting in high biomass. The amplitude ratio in the later phase of growth as on the third date is similarly altered as in the VV returns from the crop. Intuition of the rate of growth and plant vigour is obtained from the temporal PPD pattern. The current study shows that while phase differences and amplitude ratio carry little information content on a single resolution cell basis, their spatial distribution over a wider time span can be used to derive quantitative relationships between SAR response and crop condition. The synergy of information involving the above parameters were used to derive useful information on the vegetation.     

New clinical issues in celiac disease

The present study examined, in rats with N-methyl-D-aspartate-induced lesions of the basolateral amygdala, the effects of long-term adrenalectomy (i.e. 12-13 weeks) on memory for spatial and cued learning in a water maze. In sham amygdala-lesioned rats, adrenalectomy induced impairments in acquisition and retention performance for the spatial, but not the cued water-maze task. The adrenalectomized rats sustained selective degeneration and death of granule cells in the dentate gyrus dorsal blade. Continuous supplementation of the animals' drinking water with an extremely low dose of corticosterone (20 microg/ml) did not block the retention deficit, but blocked the acquisition deficit and the dentate gyrus neurodegenerative changes. The finding that the memory impairments and dentate gyrus neurodegeneration are dissociable supports the view that the adrenalectomy-induced memory effects are due to the loss of activational effects of circulating adrenal hormones at the time of learning. In adrenalectomized rats which received corticosterone as well as those which did not, lesions of the basolateral amygdala blocked the impairing effects of adrenalectomy on spatial learning and memory. However, the basolateral amygdala lesions did not affect the neurodegenerative changes in the dentate gyrus. In conclusion, the present findings provide further evidence that the basolateral amygdala is involved in regulating stress hormone effects on learning and memory.     

Delivery of mGluR5 siRNAs by Iron Oxide Nanocages by Alternating Magnetic Fields for Blocking Proliferation of Metastatic Osteosarcoma Cells

Although osteosarcoma is the most common primary malignant bone tumor, chemotherapeutic drugs and treatment have failed to increase the five-year survival rate over the last three decades. We previously demonstrated that type 5 metabotropic glutamate receptor, mGluR5, is required to proliferate metastatic osteosarcoma cells. In this work, we delivered mGluR5 siRNAs in vitro using superparamagnetic iron oxide nanocages (IO-nanocages) as delivery vehicles and applied alternating magnetic fields (AMFs) to improve mGluR5 siRNAs release. We observed functional outcomes when mGluR5 expression is silenced in human and mouse osteosarcoma cell lines. The results elucidated that the mGluR5 siRNAs were successfully delivered by IO-nanocages and their release was enhanced by AMFs, leading to mGluR5 silencing. Moreover, we observed that the proliferation of both human and mouse osteosarcoma cells decreased significantly when mGluR5 expression was silenced in the cells. This novel magnetic siRNA delivery methodology was capable of silencing mGluR5 expression significantly in osteosarcoma cell lines under the AMFs, and our data suggested that this method can be further used in future clinical applications in cancer therapy.     

A review on architecture and models for autonomic software systems

The Journal of Supercomputing - Autonomic computing was the term coined by IBM in 2001. The term autonomic computing was used to define the self-adaptable nature of the human body. According to...     

Constrained Waveform Designing for MIMO RADAR Using Jaya Optimization

Wireless Personal Communications - Multiple Input Multiple Output RADAR system is proficient in forming desired beampattern by designing transmit waveforms. In this paper, Poly Phase coded...     

Synthesis,Curing Behavior and Characterization of Epoxyacrylate and Triethylamine Cured Epoxy Resin of 1,1′-Bis(3-methyl-4-hydroxy phenyl) cyclohexane

Epoxy resin of 1,1′-bis(3-methyl-4-hydroxy phenyl) cyclohexane (EMC) and its acrylate (EMCA) have been synthesized and characterized. EMC has been cured by 5–25% triethyl amine at 100°C. The cured samples are characterized by solubility, IR, DSC and TGA at 10°C/min heating rate in nitrogen atmosphere. The associated kinetic parameters for EMCA, EMCT-5 and EMCT-20 have been determined according to Freeman-Anderson method and discussed. It is observed that EMCA and EMCT-20 have almost same thermal stability (300–308°C) but for EMCT-5 it is slightly lower (285°C). Cured samples followed fractional order degradation (0.63–1.44). In case of EMCT-5, all determined kinetic parameters are marginally lower than those of EMCA and EMCT-20.