1,607 research outputs found
Polyaniline/Polyoxometalate Hybrid Nanofibers as Cathode for Lithium Ion Batteries with Improved Lithium Storage Capacity
No full textPolyaniline is a member of the class of electrically conducting polymers, which have possible commercial applications as anticorrosive or static charge removal coatings. Aqueous-based polyaniline coatings are preferred over organic solvent or strong acid based coatings because the water used in these coatings does not pollute the environment. The overall goal of this dissertation was to further the development of useful water-based polyaniline coatings by studying new methods of synthesizing polyaniline particles for water-based coatings, to investigate the material properties of these particles such as molecular weight, electrical conductivity, particle size distribution, and stability of polyaniline in air and water. One method of polymerizing polyaniline for aqueous-based coatings uses micelles, which are composed of a cluster of amphiphile surfactants. Micelles can change the local environment by aligning and absorbing the monomer, and may yield polymers with improved material properties and reaction rates. Nonionic micelles have not been extensively investigated. Therefore the first specific goal of this work was to use an aqueous nonionic micelle solution of nonylphenoxypoly(ethyleneoxy) ethanol surfactant (NP-30 surfactant) to comprehensively investigate a one step chemical polymerization of polyaniline conducted at ?3°C, in 1.25 M HCl, with ammonium peroxydisulfate oxidizer. The results show that increasing surfactant concentrations caused a decrease in molecular weight, electrical conductivity and sharper particle size distribution of the polymer. The second specific objective of this dissertation was to determine the effect of water and air on polyaniline. The results showed no degradation of molecular weight, a decrease in chloride and hydrogen composition, and decrease in electrical conductivity for polyaniline immersed in water for extended periods. A chloride ion diffusion coefficient of 2.5 to 74 × 10<super>?9</super> cm<super>2</super>/hour was measured. The aging of polyaniline powders in a desiccator for 5 years showed no effect on the molecular structure as indicated by the FTIR spectrum. The third specific goal of the research was to measure the real and imaginary refractive index of polyaniline saturated with 1.25 M HCl, which was found to be 1.345 to 1.355 and 0.025 to 0.027, respectively. This information is crucial to measuring the distribution of polyaniline colloids by light scattering
Delinquency among students at a private institution of higher learning : a case study / Anitha M.I. Raman.
No full textNanocapsules with stimuli-responsive moieties for controlled release employing light and enzymatic triggers
No full textThe development of stimuli-responsive nanomaterials, that possess tailored functional properties for the release of specific compounds, is of particular interest. To this extent, controlling the release of molecules at the desired target is an important parameter to regulate chemical and/or biological reactions at a more profound level in a wide variety of applications. In the present work, we report on the development of dual-responsive thiourethane-urethane nanocapsules synthesizedviaan interfacial polymerization reaction executed at the droplet interface using the inverse miniemulsion technique. Evidenceviamorphological and controlled release investigations indicate that our nanocapsules are able to encapsulate hydrophilic compounds with high efficiency in their aqueous core and allow for its selective release upon exposure to UV light and the enzyme esterase. Moreover, we demonstrate the efficient encapsulation of the fragrance molecule geranyl acetate and the anticancer drug doxorubicin. For the latter, we demonstrate its apoptotic effect after being released in MCF 7 breast cancer cells. Overall, these nanocapsules can be used for a wide variety of applications where a selective release of the payload is desired.S. S. is an SB PhD Fellow at the FWO (Research Foundation Flanders). S. K. P. acknowledges BOF funding from Hasselt University. This work is supported by Hasselt University and the Research Foundation Flanders (FWO Vlaanderen; Hercules project AUHL/15/2 - GOH3816N). The authors are thankful to Prof. M. Van Bael for access to the DLS device.Pramanik, SK; Ethirajan, A (corresponding author), Hasselt Univ, Inst Mat Res IMO, Wetenschapspk 1 & Agoralaan D, B-3590 Diepenbeek, Belgium; IMEC, Associated Lab IMOMEC, Wetenschapspk 1, B-3590 Diepenbeek, Belgium;
CSIR Cent Salt & Marine Chem Res Inst, Bhavnagar 364002, Gujarat, India.
[email protected]; [email protected]
A PROSPECTIVE STUDY ON INFLUENCE OF SPECIFIC RISK FACTORS IN PATIENTS WITH CARDIOVASCULAR DISEASES AND THEIR TREATMENT
No full textSurya M. P.*, Bentolhoda Sadeghi, Anitha Vani M. and K. A. Sridha
VARIABILITY AND INFLUENCE OF ACID-BASE BALANCE IN PATIENTS WITH RENAL DYSFUNCTION
No full textMinnu Anna Chacko*, Akshatha G., Anitha Vani M. and K. A. Sridha
Ecological analysis of secondary metabolite production in Aspergillus spp.
No full textDue to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Includes bibliographical references (leaves 45-50).Issued also on microfiche from Lange Micrographics.A complex and fascinating aspect of fungal development is the production of secondary metabolites. One of the best characterized secondary metabolite pathway is the aflatoxin (AF) and sterigmatocystin (ST) pathway, found in many Aspergillus spp. These compounds are among the most potent carcinogens known. Despite the significance of Aspergillus spp. as AF/ST producers and a thorough knowledge of the steps involved in the biosynthesis pathway, the effect of AF/ST on fungal fitness and the maintenance of this phenotype in natural Aspergillus populations has not been addressed. The conservation of the AF/ST biosynthesis pathway across a broad spectrum of fungal taxa implies an ecological role. As a first step in identifying the roles of AF/ST in the ecology of the fungus, we characterized an A. flavus population isolated from a corn field in Texas to look at the maintenance of the secondary metabolite phenotype in a natural population. We also examined the costs and benefits of expression of AF/ST and AF/ST pathway intermediates under a variety of environmental conditions including those mimicking field milieu using the genetic model A. nidulans. Twenty-seven genotype groups were identified based on the RFLP fingerprints generated. Both S and L strains were present in the population. There was no relationship between sclerotia size and fluorescence (used as a surrogate for AF). Our experiments with A. nidulans indicate that ST has an effect on the fitness of the fungus. Relative fitness of the A. nidulans strains generated during this study on a given substrate was robust across treatments tested. There was a definite interaction between light and substrate. The stepwise increase in fitness as more of the ST pathway was completed on media was not faithfully duplicated on corn
Fabrication of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) Fibers Using Centrifugal Fiber Spinning: Structure, Properties and Application Potential
No full textBiobased and biodegradable polyhydroxyalkanoates (PHAs) are currently gaining momentum. Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) polymer has a useful processing window for extrusion and injection molding of packaging, agricultural and fishery applications with required flexibility. Processing PHBHHx into fibers using electrospinning or centrifugal fiber spinning (CFS) can further broaden the application area, although CFS remains rather unexplored. In this study, PHBHHx fibers are centrifugally spun from 4–12 wt.% polymer/chloroform solutions. Beads and beads-on-a-string (BOAS) fibrous structures with an average diameter (ϕav) between 0.5 and 1.6 µm form at 4–8 wt.% polymer concentrations, while more continuous fibers (ϕav = 3.6–4.6 µm) with few beads form at 10–12 wt.% polymer concentrations. This change is correlated with increased solution viscosity and enhanced mechanical properties of the fiber mats (strength, stiffness and elongation values range between 1.2–9.4 MPa, 11–93 MPa, and 102–188%, respectively), though the crystallinity degree of the fibers remains constant (33.0–34.3%). In addition, PHBHHx fibers are shown to anneal at 160 °C in a hot press into 10–20 µm compact top-layers on PHBHHx film substrates. We conclude that CFS is a promising novel processing technique for the production of PHBHHx fibers with tunable morphology and properties. Subsequent thermal post-processing as a barrier or active substrate top-layer offers new application potential
An Unusual Case of Total Anomalous Pulmonary Venous Connection in Pregnancy
No full textABSTRACT
Total anomalous pulmonary venous connection (TAPVC) is a rare congenital anomaly of the heart in which there is an absence of direct communication between the pulmonary veins and the left atrium, resulting in a mixture of oxygenated and deoxygenated blood in the right atrium. It is often associated with atrial septal defect or with transposition of great arteries, pulmonary atresia, truncus arteriosus, or single ventricle. The factors determining the severity are the severity of pulmonary venous obstruction and the restriction of interatrial communication. Uncorrected TAPVC rarely survives up to adulthood. Pregnancy in a patient with TAPVC is very rare unless surgically corrected in childhood. It often requires termination of pregnancy in first trimester as the heart cannot withstand the hemodynamic changes associated with pregnancy. We report a very rare case of pregnancy in a patient with uncorrected TAPVC, delivered successfully in our hospital without any complications.
How to cite this article
Kandasamy A, Vishwanath U, Anitha M, Mehta P. An Unusual Case of Total Anomalous Pulmonary Venous Connection in Pregnancy. J South Asian Feder Obst Gynae 2017;9(2):190-191.
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Invariant submanifolds of Sasakian manifolds admitting semi-symmetric non-metric connection, communicated
No full textThe object of this paper is to study invariant submanifolds M of Sasakian manifolds M admitting a semisymmetric nonmetric connection, and it is shown that M admits semisymmetric nonmetric connection. Further it is proved that the second fundamental forms σ and σ with respect to Levi-Civita connection and semi-symmetric nonmetric connection coincide. It is shown that if the second fundamental form σ is recurrent, 2-recurrent, generalized 2-recurrent, semiparallel, pseudoparallel, and Ricci-generalized pseudoparallel and M has parallel third fundamental form with respect to semisymmetric nonmetric connection, then M is totally geodesic with respect to Levi-Civita connection. Semisymmetric Nonmetric Connection The geometry of invariant submanifolds M of Sasakian manifolds M is carried out from 1970's by M. Kon 1 , D. Chinea 2 , K. Yano and M. Kon 3 and B.S. Anitha and C.S. Bagewadi 4 . The aurthor 1 has proved that invariant submanifold of Sasakian structure also carries Sasakian structure. In this paper we extend the results to invariant submanifolds M of Sasakian manifolds admitting Semisymmetric Nonmetric connection. We know that a connection ∇ on a manifold M is called a metric connection if there is a Riemannian metric g on M if ∇g 0; otherwise it is Nonmetric. Further it is said to be Semisymmetric if its torsion tensor T X, Y 0; thatis, T X, Y w Y X − w X Y , where w is a 1-form. A study of Semisymmetric connection on a Riemannian manifold was initiated by Yano 5 . In 1992, Agashe and Chafle 6 introduced the notion of Semisymmetric Nonmetric connection. If ∇ denotes Semisymmetric Nonmetric connection on a contact metric manifold
ELASTO-MECHANICAL CHARACTERIZATION OF SOLID-LIQUID COMPOSITES
No full textSolid-liquid composites (SLCs) are a class of soft materials with soft solid matrix encapsulating liquid inclusions. These novel composite materials have a wide range of potential applications, including thermal management, biomedicine, soft-robotics, and flexible electronics. By manipulating the type and volume of the liquid inclusion, the properties of SLCs can be fine-tuned to suit specific requirements. In this work, a dilute SLC is developed using commercial grade silicone (Smoothon Ecoflex 00-30) as the solid phase and laboratory-grade Glycerin as the liquid inclusion. While Eco-flex 00-30 mimics the behavior of a certain class of human tissues, Glycerin was selected as it is non-toxic and immiscible with silicone. A novel fabrication technique was developed for the precise distribution of the liquid inclusion in the soft polymeric material. The elastic properties of the SLCs were then determined experimentally for various volume fractions of the inclusion phase. The experimental data was then used to characterize the linear-elastic and hyperelastic material properties. The fabricated SLCs are also shown to exhibit properties similar to biofidelic materials from literature
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