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Lowell, MA, United States

Sharma D.,UMass Lowell
Journal of Thermal Analysis and Calorimetry | Year: 2012

This study explores a non-isothermal activated kinetics of the Crystalline to Smectic A (K-SmA) transition of the aligned octylcyanobiphenyl (8CB) liquid crystal. High resolution calorimetric technique was used to study the molecular motion and rearrangement of the 8CB molecules near the K-SmA transition as a function of temperature, rate, and time. In the presence of magnetic field, the transition peak was found to be shifted towards lower temperature by 0.5 K when compared with results of un-magnetized 8CB. The K-SmA transition showed a rate dependent kinetics following Arrhenius behavior where the increased shifting rate showing an increased thermal kinetics for the transition. The 8CB molecules get more aligned and more ordered that pushes the temperature of the transition towards lower temperature in the presence of magnetic field. Hence they show a temperature decrease in the peak of the transition temperature with a decrease in the enthalpy and hence needs more activation energy. This study may be useful to understand the liquid crystal behavior to upgrade liquid crystal devices (LCDs). © 2011 Akadémiai Kiadó, Budapest, Hungary. Source


Kalkan-Savoy A.,UMass Lowell
Proceedings of Meetings on Acoustics | Year: 2013

Speckle tracking imaging is used as a method to estimate heart strain. An analysis of accuracy of speckle tracking and its potential to be utilized in quantification of myocardial stress through estimation of heart motion is examined. Multiple scattering effects are modeled using the Kirchoff integral formulation for the pressure field. The method of Pade approximants is used to accelerate convergence and to obtain temporal varying characteristics of the scattered field. Phantoms having varied acoustical contrast media and speckle density are used in this study. The effectiveness of inter-image frame of correlation methods for estimating speckle motion in high contrast media is considered. © 2013 Acoustical Society of America. Source


Sharma D.,UMass Lowell
Journal of Thermal Analysis and Calorimetry | Year: 2012

Egg protein is an important part of our food to get protein in our daily diet, and makes this protein more important to researchers to understand its kinetic behavior to understand the energy involved in the digestion of the egg protein. Hence, the present study explores the denaturing kinetics of the protein obtained from the hen's egg white (EW) using high resolution calorimetric technique. Fresh EW was scanned for heating and cooling to see the thermodynamics from 10 to 100 °C at different heating ramp rates varying from 1 to 20 °C min -1. An endothermic peak was found on heating scan showing denaturing of protein which was found absent at the cooling indicating the absence of any residue after heating. The denature peak shifted towards higher temperature as ramp rate increases following Arrhenius behavior and shows an activated denaturing kinetics of the egg protein. This peak was also compared with the water to avoid water effects. Behavior of denaturing peak can be explained in terms of Arrhenius theory and further discussed to get the energy involved in digestion. © Akadémiai Kiadó, Budapest, Hungary 2012. Source


Grant
Agency: Department of Defense | Branch: Navy | Program: STTR | Phase: Phase II | Award Amount: 399.98K | Year: 2003

KaZaK Composites and UMass-Lowell will extend a successful Phase I analytical and experimental investigation of outfitting attachment hardware optimized for composite sandwich panels used as shipboard structures. The KCI/UML team will work with Bath IronWorks to ensure that attachment system solutions developed during the program are compatible with demanding and diverse needs associated with Naval fleet service. Phase I demonstrated several attachment configurations meeting static load requirements.Phase II will focus on design refinement, culminating in shock testing of attachments on full scale composite panel structures. Work will fall into the following general categories: 1) Extension of Phase I classical and finite element analysis of candidateinserts, including evaluation of effects of likely installation errors such as poor back surface attachment or misalignment, on strength of the installed attachment, 2) Fabrication of full-scale sandwich test panels made by VARTM and pultrusion processes,3) Testing candidate systems statically for in-plane and out-of-plane failure loads, 4) Subjecting final attachment hardware to shock testing, followed by measurement of strength after shock, and 5) Definition of a generally-applicable, pre-kitted panelinsert system and User's Manual for use by shipbuilders and maintenance personnel, and 6) Delivery of prototype ready-to-use kits to the Navy. KaZaK Composites is actively involved in the development of numerous products that make use of our uniquecapability to pultrude sandwich panel structures up to10 feet wide, 2 feet thick and of unlimited length. Current KCI programs include use of these pultruded sandwich panels in large deployable military buildings, Navy pier structures (with skins as thickas 3 inches) and various transportation systems. We plan to use our own developmental hardware as the first


Grant
Agency: Department of Defense | Branch: Navy | Program: STTR | Phase: Phase II | Award Amount: 602.71K | Year: 2003

In Phase II research, KTI and UML propose to optimize conditions to prepare inexpensive, bioderived, quasi-solid electrolytes and prepare various 3,4-ethylenedioxy thiophene based polymeric derivatives as a catalytic coating on electrodes, usingbiocatalytic routes. Efficient gel electrolytes were developed using biocatalytic derived, highly irregular polymeric materials during Phase I. Further studies need to be carried out to fine-tune the PV characteristics and enhance the stability of thesolar modules by optimizing the polymer structure and electrolyte components. Bioderived polymer electrolytes will be studied for thermal, rheological and photovoltaic characteristics. Solar cells and modules with an optimized polymer electrolytecomposition will be studied for long term stability at ambient as well as under accelerated thermal and solar spectrum testing conditions to optimize the gels. Hematin catalyzed polymerization technique will be used to prepare and optimize polymers forredox catalytic regeneration. The catalytic activity of polymer-coated electrodes will be studied. A detailed study will be carried out to understand the polymer structure, its coatability, stability of coating, and improving the adhesion of polymers tothe electrodes. Stability studies of optimized PEDOT based solar cells will be carried out to replace very expensive Pt with inexpensive, solution coatable polymers during Phase II research. We envision a broad set of products that are suited for militaryapplications, ranging from enhanced performance for handheld electronics (e.g., GPS) to portable (wearable) PV generators for communications, powering lightweight displays, bio-sensors, etc. We also envision our technology eventually in the form of apower-generating textile, used in soldiers' tents and field hospitals.

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