A5101647628- Textile materials and evaluations
- Polymer crystallization and properties
- Mechanical Behavior of Composites
- Material Properties and Processing
- Fiber-reinforced polymer composites
- Photonic and Optical Devices
- Epoxy Resin Curing Processes
- Natural Fiber Reinforced Composites
- Dyeing and Modifying Textile Fibers
- Advanced Sensor and Energy Harvesting Materials
- Polymer Nanocomposites and Properties
- Research in Cotton Cultivation
- Synthesis and properties of polymers
- Composite Material Mechanics
- Rheology and Fluid Dynamics Studies
- Optical Network Technologies
- Advanced Fiber Laser Technologies
- Semiconductor Lasers and Optical Devices
- Fluid Dynamics and Heat Transfer
- biodegradable polymer synthesis and properties
- Software Engineering Research
- Solidification and crystal growth phenomena
- Additive Manufacturing and 3D Printing Technologies
- Photonic Crystals and Applications
- Thin-Film Transistor Technologies
Christ University
2015-2025
GlobalFoundries (United States)
2021-2024
Netaji Subhas University of Technology
2005-2023
Institute for Plasma Research
2020-2022
All India Institute of Medical Sciences
1999-2020
Icahn School of Medicine at Mount Sinai
2018
Cornell University
2017-2018
Columbia College
2018
Royal College of Physicians
2018
Columbia University
1995-2018
Abstract The tensile mechanical properties and fracture toughness of a Bisphenol‐A type difunctional epoxy resin, cured with different amounts metaphenylene diamine, using two cure cycles, were determined over range temperature. modulus in the glassy state was seen to be predominantly related intermolecular packing, while rubbery crosslink density important factor. Yielding appeared due an increase free volume as result dilatation during test critical shear stress. large strain like...
Abstract The moisture transport characteristics of a difunctional epoxy resin cured with different amounts metaphenylene diamine, using two cure cycles, are reported. Besides studying the kinetics sorption at 20, 50, 75, and 100°C, investigations also included measurement thermal expansion coefficients dynamic mechanical transition dry wet samples. sample is shown to be related its specific volume hence fractional free volume. In glassy state, apparently in form frozen voids,...
Abstract The reduction in fiber length during extrusion and injection molding of two commercial glass fiber‐reinforced polypropylene products containing 30 percent by weight fibers was studied. first product had very small average around 0.5 mm also contained a coupling agent. second relatively longer 9 no In both cases, attrition occurs predominantly at the solid‐melt interface meiting zone extruder. However, short granules, maximum distribution, which for initial sample is mm, moved to...
Abstract High‐density polyethylene up to about 30% by weight was melt‐mixed with polypropylene and short‐glass‐fiber‐reinforced polypropylene. The presence of high‐density glass fibers in the matrix affects its crystallization characteristics, which were studied help differential scanning calorimetry. blend composite samples have a large number domains apparently due an abundance surface nuclei; as result, tensile strength, modulus, toughness are enhanced. temperature dependence shear...
Abstract We report structural changes in commercial multifilament poly(ethylene terephthalate) (PET) yarn when it is heat set silicone oil over a range of temperatures between 100 and 220°C for times ranging from 1 min to hr, while the was (1) free relax, (2) held taut at constant length. In one case, viz., sample treated cooling time also varied study effect rate cooling. The free‐annealed taut‐annealed samples showed considerable differences. predominant role temperature setting on...
Abstract Polymers develop optical and mechanical anisotropy on drawing. The measurement of the extensional modulus drawn polymer films in directions O, 45, 90† to initial draw direction (called E0, E45, E90, respectively) gives an indication extent anisotropy. On basis studies fibers it has previously been shown that nylon, polyethylene terephthalate, polypropylene, high-density give a “conventional” pattern anisotropy; i.e., E0 increases steadily with increasing ratio, at high orientations...
This paper reviews a particular form of pulsed-laser-based thin-film crystallization method referred to as controlled super-lateral growth (C-SLG). By systematically manipulating and controlling the locations, shapes, extent melting induced by incident laser pulses, C-SLG approach — notably in version sequential lateral solidification (SLS) can lead realization variety microstructurally designed crystalline Si films with low structural defect densities, including 1. large-grained...
In 44 patients with tuberculosis of the foot we identified five radiological patterns lesions; cystic, rheumatoid, subperiosteal, kissing and spina ventosa. Cystic destruction had best outcome rheumatoid poorest. All were cured after antituberculous treatment for 18 months, none required surgery.
Abstract Two commercial grades of glass fiber‐reinforced polypropylene granules, one containing short fibers average length around 0.5 mm with a coupling agent and the other relatively much longer mostly 9 mm, but no agent, were injection‐molded into dumbbells tested in tension between −43 90°C. There is considerable fiber attrition during injection molding; lengths are reduced to values 0.4 0.8 for thses two samples. Also molding test sample, partial molecular alignment matrix...
Abstract The mechanical anisotropy of polyethylene has been investigated by making measurements tensile modulus on thin strips cut at various directions in the plane from anisotropic sheets with a wide range physical structures. Conventional possessing fiber symmetry were made uniaxial stretching high- and low-density sheets, some cases accompanied heat-annealing. Sheets lower orthorhombic oriented rolling annealing processes recently established Hay Keller [1]. In all moduli angles 0, 45,...
Enabling cost-effective and power-efficient laser source on a silicon photonics (SiPh) platform is major goal that has been highly sought after. In the past two decades, tremendous effort made to develop various on-chip integration techniques enhance SiPh circuits with efficient light-emitting materials. Here we review our recent advancements in hybrid flip-chip of III-V lasers 300-mm monolithic platform. By leveraging advanced complementary metal oxide semiconductor (CMOS) manufacturing...
The tensile stress–strain and recovery behavior of all the four commercial varieties Indian silk fibers, namely Mulberry, Tasar, Eri, Muga, have been studied along with their structures. Compared to non-Mulberry Mulberry fiber is much finer has crystallites smaller size, higher molecular orientation, a more compact overall packing molecules. These structural differences shown result in (1) presence distinct yield plateau absence silk, (2) relatively initial modulus tenacity lower...
Abstract In the existing literature various values are given for intrinsic birefringence of crystalline and amorphous phases in poly(ethylene terephthalate) (PET). These have either been calculated theoretically or obtained from experimental data on basis certain models. this investigation, using Samuels two‐phase model which correlates sonic modulus with structural parameters, (Δ n c ) a determined by studying 30 PET samples prepared heat setting to wide range structures; results Δ = 0.29...
Abstract As‐manufactured polymeric fibers are oriented semi‐crystalline structures in which the macromolecules rarely their equilibrium state. Further instabilities imparted when converted to yarns and fabrics. Heat setting is an important industrial process, since it rids them of instabilities. This review article first considers aspects that relevant broad area heat setting, viz., origin instability, durability set, thermal dynamic mechanical transitions, thermodynamic basis shrinkage...
Mid- and near-infrared (IR) spectroscopy has been used to study the curing of a bisphenol-A based epoxy resin (EPON-828) with tetrafunctional agent, viz., meta-phenylenediamine (MPDA). Three different cure cycles were in study. Primary amine functionality was observed react relatively rapidly; none remained after for 2 h at 75°C. Secondary exhausted rich samples subjected standard cycle (2 75°C followed by 125°C). In stoichiometric amount or higher MPDA, complete reaction secondary groups...
Abstract Poly(ethylene terephthalate) (PET) fibers having a range of structure and morphology were prepared by heat‐setting commercial PET yarn at temperatures 100–250°C for 5 min under two conditions, while the was free to relax when it held taut constant length. The crystallinity, crystallinity orientation, crystallite size determined X‐ray diffraction birefringence measured with help optical microscopy. amorphous orientation factor computed from structural parameters. coupling between...
Abstract We have recently studied the anisotropy of tensile modulus in cold-drawn low-density polyethylene films over temperature range −125 to 60°C [l]. The pattern has been explained by a theoretical model [2] which polymer is regarded s an aggregate anisotropic units whose properties are those most highly oriented film. compliances this draw direction S33 and perpendicular , using Reuss scheme for averaging, given following relationships.