Effect of Temperature on Aging of Ferroelectric Lead-Strontium-Zirconate-Titanate Ceramics

The effect of aging on Sr2+ modified Lead Zirconate Titanate (PSZT) ceramics have been studied. Aging was assessed by the measurement of dielectric constant and dielectric loss tangent as a function of time and temperature. Dielectric constant and dielectric loss tangent measured at different temperature range. Absolute rate of aging and relative rate of aging was determined. The PSZT ceramic showed sharp dielectric peak at temperature 300oC. The result showed that with increased temperature both the dielectric constant and rate of aging increased.Defence Science Journal, 2010, 60(6), pp.683-686, DOI:http://dx.doi.org/10.14429/dsj.60.5

Antifungal Activity of Petrolium and Ethanolic Extracts of Moringa Oleifera Leaves against Penicillium Chrysogenum and Cryptococcus Neoformans

Moringa oleifera is well known medicinal plant. Its different parts are widely used for the treatment of different types of diseases since is have antibacterial and antifungal activity. The leaves are rich in iron, rhamnose and a unique group of compounds called glucosinolates and isothiocyanates. Other medical proprieties include antipyretic, antiepileptic, antiinflamatory, antiulcerative, antihypertensive, cholesterol lowering, antioxidant, anti diabetic. The current investigation was undertaken to evaluate the antifungal activities by petroleum ether and ethanolic extracts of Moringa oleifera leaves against Penicillium crysogenum and Cryptococcus neoformans. From our study, it is found that as concentration of Moringa leaves extract increases the diameter of zone of inhibition found increased. The results were higher and effective for ethanolic extract than petroleum extract. The result were also found more effective against Cryptococcus neoformans than Penicillium crysogenum

Improved FPT Algorithms for Deletion to Forest-Like Structures

The Feedback Vertex Set problem is undoubtedly one of the most well-studied problems in Parameterized Complexity. In this problem, given an undirected graph G and a non-negative integer k, the objective is to test whether there exists a subset S ? V(G) of size at most k such that G-S is a forest. After a long line of improvement, recently, Li and Nederlof [SODA, 2020] designed a randomized algorithm for the problem running in time ?^?(2.7^k). In the Parameterized Complexity literature, several problems around Feedback Vertex Set have been studied. Some of these include Independent Feedback Vertex Set (where the set S should be an independent set in G), Almost Forest Deletion and Pseudoforest Deletion. In Pseudoforest Deletion, each connected component in G-S has at most one cycle in it. However, in Almost Forest Deletion, the input is a graph G and non-negative integers k,? ? ?, and the objective is to test whether there exists a vertex subset S of size at most k, such that G-S is ? edges away from a forest. In this paper, using the methodology of Li and Nederlof [SODA, 2020], we obtain the current fastest algorithms for all these problems. In particular we obtain following randomized algorithms. 1) Independent Feedback Vertex Set can be solved in time ?^?(2.7^k). 2) Pseudo Forest Deletion can be solved in time ?^?(2.85^k). 3) Almost Forest Deletion can be solved in ?^?(min{2.85^k ? 8.54^?, 2.7^k ? 36.61^?, 3^k ? 1.78^?})

Pb(Ni1/3Sb2/3)O3-PbZrTiO3 Ceramic Sensors for Underwater Transducer Application

Cymbal is a class-V flextensional transducer that consists of thickness poled ceramic disc sandwiched between the two metal end caps which acts as a mechanical transformer. Cymbal transducers were fabricated using piezoceramic discs of compositions Pb0.988(Zr0.52Ti0.48) 0.976Nb0.024O3 (PZT type 5A) and Pb0.98La0.02 (NiSb)0.05[(Zr0.52 Ti0.48)0.995]0.95O3 (PNS-PZT). Piezoelectric and hydrostatic constants for PNS-PZT composition were on higher side. End capswere made up of brass sheet having thickness 0.5 mm. Underwater testing of the polyurethane moulded cymbal hydrophones were carried out in acoustic tank and compared. The resonance frequency for both the hydrophones was 10.1 kHz. PNS-PZT hydrophone shows higher sensitivity (-183.2 dB re 1V/μPa) compared to PZT type 5A (-191.2 dB re 1V/μPa) at resonance frequency. Directivity pattern observed for PNS-PZT is omni-directional near resonance frequency.Defence Science Journal, 2012, 62(4), pp.269-273, DOI:http://dx.doi.org/10.14429/dsj.62.171

Report of a TREAT-NMD/World Duchenne Organisation Meeting on Dystrophin Quantification Methodology

Representatives of academia, patient organisations, industry and the United States Food and Drug Administration attended a workshop on dystrophin quantification methodology. The aims of the workshop were to provide an overview of methods used to quantify dystrophin levels in human skeletal muscle and their applicability to clinical trial samples, outline the gaps with regards to validating the methods for robust clinical applications prior to regulatory agency review, and to align future efforts towards further optimizing these methods. The workshop facilitated a constructive but also critical discussion on the potential and limitations of techniques currently used in the field of translational research (western blot and immunofluorescence analysis) and emerging techniques (mass spectrometry and capillary western immunoassay). Notably, all participants reported variation in dystrophin levels between muscle biopsies from different healthy individuals and agreed on the need for a common reference sample

Constrained flexibility in PNA: DNA binding studies with bridged aminopropylglycyl PNA

Introduction of methylene bridges in aegPNA and apgPNA molecules give rise to cyclic five and six membered ring structures. Synthesis of a new six membered cyclic PNA monomer, aminopipecolyl PNA (pipPNA) is reported. Incorporation of pipPNA into PNA oligomers and comparative binding with target DNA sequences is studied

Photooxidation of polypropylene/layered double hydroxide nanocomposites: Influence of intralamellar cations

International audienceThe influence of layered double hydroxides (LDHs) on the photooxidation of polypropylene (PP)/LDH nanocomposites was studied under irradiation at long wavelengths (λ > 300 nm, 60 °C and in the presence of oxygen). The influence of hybrid LDHs containing different divalent cations (Mg, Zn or both Mg and Zn) on the photooxidation mechanism of PP and on the rates of oxidation of the matrix was characterised based on infrared analysis. The presence of LDHs modifies the photoproducts accumulating in the PP and the rates of oxidation of PP were changed depending on the divalent cations in the LDH layers. Whereas natural clays, such as montmorillonite (MMt), can lead to a faster degradation of the materials, LDHs (Zn2-Al-DS, for example) appear to have no inductive effect on polymer oxidation

Preparation and nonisothermal crystallization behavior of polypropylene/layered double hydroxide nanocomposites

International audiencePolypropylene (PP)/layered double hydroxide (LDH) nanocomposites were prepd. via melt intercalation using dodecylsulfate anion modified LDH and maleated PP as compatibilizing agent. Evidently the interlayer anions in LDH galleries react with maleic anhydride groups of PP-g-MA and lead to a finer dispersion of individual LDH layers in the PP matrix. The nanostructure was characterized by XRD and TEM; the examns. confirmed the nanocomposite formation with exfoliated/intercalated layered double hydroxides well distributed in the PP matrix. The nonisothermal crystn. behavior of resulting nanocomposites was extensively studied using differential scanning calorimetry (DSC) technique at various cooling rates. In nonisothermal crystn. kinetics, the Ozawa approach failed to describe the crystn. behavior of nanocomposites, whereas the Avrami anal. and Jeziorny method well define the crystn. behavior of PP/LDH nanocomposite. Combined Avrami and Ozawa anal. (Liu model) also found useful. The results revealed that very small amts. of LDH (1%) could accelerate the crystn. process relative to the pure PP and increase in the crystn. rates was attributed to the nucleating effect of the nanoparticles. Polarized optical microscopy (POM) observations also support the DSC results. The effective crystn. activation energy was estd. as a function of the relative degree of crystallinity using the isoconversional anal. Overall, results indicated that the LDH particles in nanometer size might act as nucleating agent and distinctly change the type of nucleation, growth and geometry of PP crystals

Assessment of Ground Water Quality in Gajanan Colony, Ahmednagar. by Water Quality Index (WQI)

A water quality analysis was carried out in Ahmednagar city. Different parameters were analyzed that are pH, alkalinity, turbidity, TDS, total hardness and chlorides. The sampling sites showed that the physicocmc al parameters were within the water quality standards and the quality of water was found to be fit for drinking.Water is an essential natural resource for sustaining life and environment but over the last few decades the water quality is deteriorating due to it's over exploitation. Water quality is essential parameter to be studied when the overall focus is sustainable development keeping mankind at focal point. Groundwater is the major source of drinking water in rural as well as in urban areas and over 94% of the drinking water demand is met by groundwater.Assessment ground water quality is necessary as it controls it's as usability for drinking purpose .The study was carried out by the physic-chemical and biological analysis of ground water quality