Vijayaprakash K.M.,Frontier Engineering |
Sridharan N.,University of Madras
Journal of Pharmacology and Pharmacotherapeutics | Year: 2013
Till date, NYU MASCIS (New York University, Multicenter Animal Spinal Cord Injury Study) impactor and Ohio State University electromagnetic spinal cord injury device impactor were under use for simulating an experimental spinal cord injury in rodents; functional recovery being assessed through Basso, Beattie and Bresnahan (BBB) scoring method which is an open field behavior based scoring system. Although, the cited impactors are state-of-Art devices, affordability to scientists in developing and under developed countries is questionable. Since the acquisition of these impact devices are expensive, we designed a customized impact device based on the requirement, satisfying all the parameters to withstand a standard animal model for contusion type of spinal cord injury at the thoracic level without compromising the lesion reproducibility. Here, a spinal cord contusion is created using a blunt-force impactor in male Wistar rats. Our method gave consistent lesion effects as evaluated by behavior scoring methods. All the animals showed equal degree of performance in tests like narrow beam, inclined plane and horizontal ladder and in BBB scores (open field locomotor test). The aim of presenting our experience is to reinstate the fact that lack of affordability to get sophisticated instrumentation need not be a hurdle in the pursuit of science.
Chen Y.,Frontier Engineering |
Kakuchi T.,Changchun University
Chemical Record | Year: 2016
In contrast to the conventional group transfer polymerization (GTP) using a catalyst of either an anionic nucleophile or a transition-metal compound, the organocatalyzed GTP has to a great extent improved the living characteristics of the polymerization from the viewpoints of synthesizing structurally well-defined acrylic polymers and constructing defect-free polymer architectures. In this article, we describe the organocatalyzed GTP from a relatively personal perspective to provide our colleagues with a perspicuous and systematic overview on its recent progress as well as a reply to the curiosity of how excellently the organocatalysts have performed in this field. The stated perspectives of this review mainly cover five aspects, in terms of the assessment of the livingness of the polymerization, limit and scope of applicable monomers, mechanistic studies, control of the polymer structure, and a new GTP methodology involving the use of tris(pentafluorophenyl)borane and hydrosilane. © 2016 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Gondhalekar R.,Frontier Engineering |
Jones C.N.,ETH Zurich
Automatica | Year: 2011
State-feedback model predictive control (MPC) of discrete-time linear periodic systems with time-dependent state and input dimensions is considered. The states and inputs are subject to periodically time-dependent, hard, convex, polyhedral constraints. First, periodic controlled and positively invariant sets are characterized, and a method to determine the maximum periodic controlled and positively invariant sets is derived. The proposed periodic controlled invariant sets are then employed in the design of least-restrictive strongly feasible reference-tracking MPC problems. The proposed periodic positively invariant sets are employed in combination with well-known results on optimal unconstrained periodic linear-quadratic regulation (LQR) to yield constrained periodic LQR control laws that are stabilizing and optimal. One motivation for systems with time-dependent dimensions is efficient control law synthesis for discrete-time systems with asynchronous inputs, for which a novel modeling framework resulting in low dimensional models is proposed. The presented methods are applied to a multirate nano-positioning system. © 2010 Elsevier Ltd. All rights reserved.
Kumar R.,Frontier Engineering |
Hoshimoto Y.,Frontier Engineering |
Hoshimoto Y.,Japan Science and Technology Agency |
Yabuki H.,Frontier Engineering |
And 2 more authors.
Journal of the American Chemical Society | Year: 2015
A highly enantioselective synthesis of 3-aryl-, vinyl-, and alkynyl-2,1-benzoxasiloles (up to 99.9% ee and 99% yield) was achieved via the sequential activation of an aldehyde and a silane by nickel(0). This strategy was applied to a simultaneous generation of carbon- and silicon-stereogenic centers with excellent selectivity (dr = 99:1) via diastereotopic aryl transfer. Initial mechanistic studies revealed the complete switching of an aryl-transfer process from an intermolecular (racemic synthesis in the presence of IPr) to an intramolecular (enantioselective synthesis using chiral NHC, L5) fashion. A plausible rationale for the switching of the aryl-transfer process is given by a preliminary DFT calculation, which suggests that the coordination of 1 to the nickel(0)/L5 fragment in an 2-arene:2-aldehyde fashion would be a key to the intramolecular process, while the formation of the corresponding intermediate is not possible in the presence of IPr. Owing to the chemically labile nature of its C-Si and O-Si bonds, enantioenriched benzoxasiloles are utilized for the synthesis of chiral building blocks and antihistaminic and anticholinergic drug molecules such as (R)-orphenadrine and (S)-neobenodine with no erosion of the enantiomeric excess. © 2015 American Chemical Society.
Ohkuma T.,Frontier Engineering |
Arai N.,Hokkaido UniversityN13 W8
Chemical Record | Year: 2016
Catalytic asymmetric hydrogenation of ketones through the "metal-ligand cooperative mechanism" has been improved in terms of the efficiency, stereoselectivity, and scope of substrates by varying the arrangement of the catalyst structure and reaction conditions. Imino compounds are also smoothly converted to the optically active amines with appropriate catalysts. This type of catalyst exhibits excellent performance on the asymmetric isomerization of primary allylic alcohols into the optically active aldehydes. This personal account describes recent progress on these topics. © 2016 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Ajrash M.J.,Frontier Engineering |
Zanganeh J.,Frontier Engineering |
Moghtaderi B.,Frontier Engineering
Journal of Loss Prevention in the Process Industries | Year: 2016
Deflagration explosions of coal dust clouds and flammable gases are a major safety concern in coal mining industry. Accidental fire and explosion caused by coal dust cloud can impose substantial losses and damages to people and properties in underground coal mines. Hybrid mixtures of methane and coal dust have the potential to reduce the minimum activation energy of a combustion reaction. In this study the Minimum Explosion Concentration (MEC), Over Pressure Rise (OPR), deflagration index for gas and dust hybrid mixtures (Kst) and explosive region of hybrid fuel mixtures present in Ventilation Air Methane (VAM) were investigated. Experiments were carried out according to the ASTM E1226-12 guideline utilising a 20 L spherical shape apparatus specifically designed for this purpose. Results: obtained from this study have shown that the presence of methane significantly affects explosion characteristics of coal dust clouds. Dilute concentrations of methane, 0.75-1.25%, resulted in coal dust clouds OPR increasing from 0.3 bar to 2.2 bar and boosting the Kst value from 10 bar m s-1 to 25 bar m s-1. The explosion characteristics were also affected by the ignitors' energy; for instance, for a coal dust cloud concentration of 50 g m-3 the OPR recorded was 0.09 bar when a 1 kJ chemical ignitor was used, while, 0.75 bar (OPR) was recorded when a 10 kJ chemical ignitor was used.For the first time, new explosion regions were identified for diluted methane-coal dust cloud mixtures when using 1, 5 and 10 kJ ignitors. Finally, the Le-Chatelier mixing rule was modified to predict the lower explosion limit of methane-coal dust cloud hybrid mixtures considering the energy of the ignitors. © 2015 Elsevier Ltd.
Liang C.-H.,Frontier Engineering |
Hwang C.-S.,Frontier Engineering
Journal of Alloys and Compounds | Year: 2010
A nanoscale hydrous manganese oxide used as an electrode in a supercapacitor was deposited onto a titanium substrate from an aqueous manganese acetate solution using the hydrothermal electrochemical method. The effect of deposition temperature on the characteristics of the manganese oxides was investigated. The capacitive characteristics of the manganese oxides were measured in sulfate electrolytes with various cations using cyclic voltammetry. The capacitive performances of the manganese oxide electrodes depend on the deposition temperature as well as the cations of electrolytes. A maximum capacitance of 244 F g -1 was obtained in Na 2SO 4 solution. The stability of manganese oxide was examined; after 1000 cycles, 80% of the initial capacitance remained. Crown Copyright © 2010.
Ramesh B.,Frontier Engineering
Artificial cells, nanomedicine, and biotechnology (Print) | Year: 2013
The quest for RBCs in transfusion medicine has prompted scientists to explore the large-scale expansion of human RBCs from various sources. The successful production of RBCs in the laboratory depends on the selection of potential cell source, optimized culture, bio-physiological parameters, clinically applicable culture media that yields a scalable, contamination-free, non-reactive, non-tumorogenic, stable and functional end product. The expansion protocol considering the in vivo factors involved in homeostasis can generate a cost-effective and readily available cell source for transfusion. This review paper discusses several approaches used to expand RBCs from various sources of stem cells.
Gondhalekar R.,Frontier Engineering |
Imurab J.-I.,Tokyo Institute of Technology
Automatica | Year: 2010
Move-blocking lowers the computational complexity of model predictive control (MPC) problems by reducing the number of optimization variables. However, this may render states close to constraints infeasible. Thus move-blocking generally results in control laws that are restrictive; the controller domains may be unacceptably and unnecessarily small. Furthermore, different move-blocking strategies may result in controller domains of different sizes, all other factors being equal. In this paper an approach is proposed to design move-blocking MPC control laws that are least-restrictive, i.e. the controller domain is equal to the maximum controlled invariant set. The domains of different move-blocking controllers are then by design equal to each other. This allows comparison of differing move-blocking strategies based on cost performance only, without needing to consider domain size also. Thus this paper is a step towards being able to derive optimal move-blocking MPC control laws. © 2010 Elsevier Ltd. All rights reserved.
Agency: Department of Defense | Branch: Missile Defense Agency | Program: SBIR | Phase: Phase I | Award Amount: 99.77K | Year: 2010
This proposal provides an innovative solution to reduce the size and mass of a precision regulator used on typical liquid DACS systems. Novel friction-reducing Belleville washer designs and a secondary spring unit keep the regulator compact, simple and low weight while maintaining a +/-5% regulated pressure outlet tolerance. The simple temperature-compensating device keeps the size small and helps increase regulation precision. Low seat stress materials will keep the lockup pressure increase low.