Thermodynamic and kinetic analysis on Cl.+RCI -- Cl2+R.reactions, CH3CjO+O2= products and CjCHO+O2= products

Thermodynamic Parameters, ΔH°f(298), S°(298) and Cp(T) are evaluated for C1 and C2 chlorocarbon molecules and radicals. These thermodynamic properties are used in evaluation and comparison of R.+ Cl2 =\u3e R-Cl + Cl. (defined forward direction) reaction rate constants from the kinetics literature. Data from some 20 reactions in the literature show linearity on a plot of Eafwd vs. ΔHrxn,fwd, yielding a slope of (0.38 ± 0.04) and intercept of (10.10 ± 0.77) kcal/mole. Thermodynamic properties (ΔH°(298), S°(298) and Cp(T) from 300 to 1500 K) for reactants, adducts, transition states, and products in reactions of CH3 and C2H5 with Cl2 are calculated using CBSQ//MP2/6-311G(d,p). Evaluated thermodynamic property data are presented for all isomers of the stable molecules CH3Cl, CH2Cl2, CHCl3, CC14, C2H5Cl, C2H4Cl2, C2H3Cl3, C2H2CI4, C2HCl5, C2Cl6, C2H3Cl, C2H2C22, C2HCl3, and C2Cl4. Evaluated thermodynamic property data are also presented for the alkyl radicals, (including isomers) C·H2CL·, C·HCl2, C·Cl3, C2H4Cl·, C2H3Cl2·, C2H2Cl3·, C2HCl4·, and C2Cl5·, for the olefin radicals (including isomers) C2H2Cl·, C2HCl2·, and C2Cl3;. Thermodynamic property and chemical kinetic analysis are performed on reactants, intermediates, transition states and products from reactions of the two radicals resulting via H atom abstraction from acetaldehyde: CH3CjO and CjCHO with molecular oxygen. Density functional and ab initio calculations are utilized to estimate thermodynamic properties: ΔHf°298, and Cp°(T) 300 - 1500K. Rate constants are estimated as a function of temperature and pressure using QRRK analysis for k(E) and modified strong collision analysis for fall-off for application to atmospheric and combustion kinetic modeling. The important reaction paths are determined as: CH3CjO + O2 ---\u3e CH 2CO + HO2 via HO2 Elimination CH3CjO + O2 ---\u3e CyCOCO=O + OH via OH Elimination CH3CjO + O2 ---\u3e CCOQj (Stabilization) CjCHO + O2 ---\u3e CO + C.H2OOH via H shift (C.H2OOH rapidly decays to CH2O + OH) CjCHO + O2 ---\u3e CQjCHO (Stabilization

Thermochemistry and kinetic analysis on radicals of acetaldehyde + O2, allyl radical + O2 and diethyl and chlorodiethyl sulfides

Thermochemical properties for reactants, intermediates, products and transition states important in the radicals of acetaldehyde + O2 and allyl radical + O2 reaction systems are analyzed with density functional and ab initic calculations, to evaluate the reaction paths and kinetics in oxidation and pyrolysis. Ketene is one important product resulting from acetaldehyde oxidation; thus thermochemistry plus isomerization and conversion reactions of ketene are also analyzed. Enthalpies of formation are determined using isodesmic reaction analysis at the CBSQ composite and density functional levels. Entropies and heat capacities are determined using geometric parameters and vibration frequencies obtained at the HF/6-31G(d\u27) or B3LYP/6-31G(d,p) level of theory. Internal rotor contributions are included in calculation of entropy, S°298, and heat capacities, Cp(T). Rate constants are estimated as a function of pressure and temperature using multifrequency quantum Rice-Ramsperger-Kassel analysis for k(E) and master equation analysis for falloff. A mechanism for pyrolysis and oxidation of acetaldehyde and its\u27 corresponding radicals is constructed. The competition between reactions of radicals of acetaldehyde with O2 versus unimolecular decomposition is evaluated versus temperature and pressure. Thermodynamic parameters, enthalpies, entropies and heat capacities are evaluated for C1 and C2 chlorocarbon molecules and radicals. These thermodynamic properties are used in evaluation and comparison of Cl2 + R. \u3c--\u3e Cl. + RCl reaction rate constants from the kinetics literature for comparison with empirical analysis. Data from some 20 reactions in the literature show linearity on a plot of Eafwd vs Δrxn, fwd, yielding a slope of (0.38 ± 0.04) and an intercept of (10.12 ± 0.81) kcal/mol. The use of Density Functional Theory, B3LYP/6-31g(d,p), with isodesmic working reactions for enthalpy of formation of sulfur hydrocarbons is evaluated using a set of known sulfur hydrocarbon / radical species. Thermodynamic and kinetic parameters for reactants, transition states, and products from unimolecular dissociations of sulfur species related to the chemical agent: CH3CH2SCH2CH2, CH3CH2SCH2CH2Cl, and CH2ClCH2SCH2CH2Cl and corresponding radicals are analyzed. Standard enthalpy, ΔHf°298, for the molecules and radicals are determined using isodesmic reaction analysis at the B3LYP/6-31G(d,p) level, with S°298 and Cp(T) determined using geometric parameters and vibrational frequencies obtained at this same level of theory. Potential barriers for the internal rotor potentials are also calculated at the B3LYP/6-31G(d,p) level, and the hindered rotation contributions to S°298 and Cp(T) are calculated

A Comparative Study on the L-1 Optimal Event-Based Method for Biped Walking on Rough Terrains

This paper is concerned with a comparative study of biped walking on rough terrains. Given a bipedal robot capable of walking on a flat ground with periodic behavior, whose motion can be described by a limit cycle with the Poincare map, we consider whether the robot remains stable on rough terrain, in which geometrical uncertainties of the terrain are assumed to be persistent and bounded. More precisely, the l(infinity)-induced norm is defined on the Poincare map and taken as a performance measure evaluating a robot walking with the bounded persistent uncertainties. To minimize the performance measure and achieve an optimal walking performance, we further provide a systematic controller design scheme consisting of a inner-loop continuous-time controller and a outer-loop event-based controller, in which the latter is described as a sort of the l(1) optimal controller. Finally, the validity as well as the effectiveness of our proposed methods in biped walking on a rough terrain are demonstrated through simulation studies.11Yscopu

A Closed-Loop Deep Brain Stimulation Device With a Logarithmic Pipeline ADC.

This dissertation is a summary of the research on integrated closed-loop deep brain stimulation for treatment of Parkinson’s disease. Parkinson's disease is a progressive disorder of the central nervous system affecting more than three million people in the United States. Deep Brain Stimulation (DBS) is one of the most effective treatments of Parkinson’s symptoms. DBS excites the Subthalamic Nucleus (STN) with a high frequency electrical signal. The proposed device is a single-chip closed-loop DBS (CDBS) system. Closed-loop feedback of sensed neural activity promises better control and optimization of stimulation parameters than with open-loop devices. Thanks to a novel architecture, the prototype system incorporates more functionality yet consumes less power and area compared to other systems. Eight front-end low-noise neural amplifiers (LNAs) are multiplexed to a single high-dynamic-range logarithmic, pipeline analog-to-digital converter (ADC). To save area and power consumption, a high dynamic-range log ADC is used, making analog automatic gain control unnecessary. The redundant 1.5b architecture relaxes the requirements for the comparator accuracy and comparator reference voltage accuracy. Instead of an analog filter, an on-chip digital filter separates the low frequency neural field potential signal from the neural spike energy. An on-chip controller generates stimulation patterns to control the 64 on-chip current-steering DACs. The 64 DACs are formed as a cascade of a single shared 2-bit coarse current DAC and 64 individual bi-directional 4-bit fine DACs. The coarse/fine configuration saves die area since the MSB devices tend to be large. Real-time neural activity was recorded with the prototype device connected to microprobes that were chronically implanted in two Long Evans rats. The recorded in-vivo signal clearly shows neural spikes of 10.2 dB signal-to-noise ratio (SNR) as well as a periodic artifact from neural stimulation. The recorded neural information has been analyzed with single unit sorting and principal component analysis (PCA). The PCA scattering plots from multi-layers of cortex represent diverse information from either single or multiple neural sources. The single-unit neural sorting analysis along with PCA verifies the feasibility of the implantable CDBS device for to in-vivo neural recording interface applications.Ph.D.Electrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/60733/1/milaca_1.pd

Leaders Need to Be Led: Complementary Followership through Interchangeable Roles among Leader-Follower Positions

Leadership is often recognized as a major driver for successful team effectiveness. However, even weak leadership may show good team performance, and it is worth studying how weak leadership can be helped and complemented by followership. To investigate this paradoxical mechanism behind leadership-followership practices, we examined (1) multi-dimensional figures of leadership and followership using the multifactor leadership questionnaire (MLQ), and (2) the impacts of the combinations of leadership and followership on team performances both during and after a community-driven development (CDD) program. To that end, this study examined a rural CDD case implemented by the Korea International Cooperation Agency (KOICA) and the Myanmar Ministry of Agriculture, Livestock, and Irrigation (MOALI). The CDD leaders of 100 villages (and randomly selected residents of each village) were surveyed. And the collected data were analyzed using regression analysis method. The analyses present some common patterns of how weak leadership and strong followership can lead to better performance than other combinations of leadership and followership. First, the W-S state (Weak leadership and Strong followership) could be better for CDD performances than S-S (Strong leadership and Strong followership) and S-W (Strong leadership and Weak followership). This means that W-S is a necessary condition for successful group performance, which implies that having weak leadership can be an opportunity for strengthening followership. In detail, from the followers’ perspective, strong followership in some factors (intellectual stimulation, individualized consideration, and contingent reward) may best complement weak leadership in the same factors during CDD program. For the sustainability of community development, followership in idealized influence (i.e., trustful dedication) can help complement weak leadership so as to sustain community development even after the CDD program completed. Second, strong leadership could be detrimental to CDD performances because there were some negative impacts of S-S (Strong leadership and Strong followership) and S-W (Strong leadership and Weak followership). We conclude with theoretical and practical conditions of “complementary followership” i.e., the complementary combinations of leadership and followership in group performance

Hierarchical controller for highly dynamic locomotion utilizing pattern modulation and impedance control : implementation on the MIT Cheetah robot

Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (pages 105-111).This thesis presents a hierarchical control algorithm for quadrupedal locomotion. We address three challenges in developing a controller for high-speed running: locomotion stability, control of ground reaction force, and coordination of four limbs. To tackle these challenges, the proposed algorithm employs three strategies. Leg impedance control provides programmable virtual compliance of each leg which achieve self-stability in locomotion. The four legs exert forces to the ground using equilibrium-point hypothesis. A gait pattern modulator imposes a desired footfall sequence. The control algorithm is verified in a dynamic simulator constructed using MATLAB and then in the subsequent experiments on the MIT Cheetah robot. The experiments on the MIT Cheetah robot demonstrates high speed trot running reaching up to the speed of 6 m/s on a treadmill. This speed corresponds to a Froude number (Fr = 7.34), which is comparatively higher than other existing quadrupedal robots.by Jongwoo Lee.S.M

The Cis-regulatory Logic of the Mammalian Photoreceptor Transcriptional Network

The photoreceptor cells of the retina are subject to a greater number of genetic diseases than any other cell type in the human body. The majority of more than 120 cloned human blindness genes are highly expressed in photoreceptors. In order to establish an integrative framework in which to understand these diseases, we have undertaken an experimental and computational analysis of the network controlled by the mammalian photoreceptor transcription factors, Crx, Nrl, and Nr2e3. Using microarray and in situ hybridization datasets we have produced a model of this network which contains over 600 genes, including numerous retinal disease loci as well as previously uncharacterized photoreceptor transcription factors. To elucidate the connectivity of this network, we devised a computational algorithm to identify the photoreceptor-specific cis-regulatory elements (CREs) mediating the interactions between these transcription factors and their target genes. In vivo validation of our computational predictions resulted in the discovery of 19 novel photoreceptor-specific CREs near retinal disease genes. Examination of these CREs permitted the definition of a simple cis-regulatory grammar rule associated with high-level expression. To test the generality of this rule, we used an expanded form of it as a selection filter to evolve photoreceptor CREs from random DNA sequences in silico. When fused to fluorescent reporters, these evolved CREs drove strong, photoreceptor-specific expression in vivo. This study represents the first systematic identification and in vivo validation of CREs in a mammalian neuronal cell type and lays the groundwork for a systems biology of photoreceptor transcriptional regulation

Relative Navigation with Intermittent Laser-based Measurement for Spacecraft Formation Flying

This paper presents relative navigation using intermittent laser-based measurement data for spacecraft flying formation that consist of two spacecrafts; namely, chief and deputy spacecrafts. The measurement data consists of the relative distance measured by a femtosecond laser, and the relative angles between the two spacecrafts. The filtering algorithms used for the relative navigation are the extended Kalman filter (EKF), unscented Kalman filter (UKF), and least squares recursive filter (LSRF). Numerical simulations reveal that the relative navigation performances of the EKF- and UKF-based relative navigation algorithms decrease in accuracy as the measurement outage period increases. However, the relative navigation performance of the UKF-based algorithm is 95 % more accurate than that of the EKF-based algorithm when the measurement outage period is 80 sec. Although the relative navigation performance of the LSRF-based relative navigation algorithm is 94 % and 370 % less accurate than those of the EKF- and UKF-based navigation algorithms, respectively, when the measurement outage period is 5 sec; the navigation error varies within a range of 4 %, even though the measurement outage period is increased. The results of this study can be applied to the design of a relative navigation strategy using the developed algorithms with laser-based measurements for spacecraft formation flying