Bibliographies thématiques / Ground state redox potential

Littérature scientifique sur le sujet « Ground state redox potential »

Auteur : Grafiati
Publié le 10 mars 2023

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Articles de revues sur le sujet "Ground state redox potential"

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Mohammadpourasl, Sanaz, Fabrizia Fabrizi de Biani, Carmen Coppola, Maria Laura Parisi, Lorenzo Zani, Alessio Dessì, Massimo Calamante, Gianna Reginato, Riccardo Basosi et Adalgisa Sinicropi. « Ground-State Redox Potentials Calculations of D-π-A and D-A-π-A Organic Dyes for DSSC and Visible-Light-Driven Hydrogen Production ». Energies 13, no 8 (19 avril 2020) : 2032. http://dx.doi.org/10.3390/en13082032.

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The prediction of ground-state redox potentials by quantum chemical methods has a prominent role in the rational design of novel organic photosensitizers both for dye-sensitized solar cells (DSSCs) and photocatalytic systems for the production of H2. Indeed, the ground-state redox potential of the photosensitizers is one of the key parameters to identify the most promising candidates for such applications. Here, the ground-state redox potentials of 16 organic donor-π-acceptor D-π-A and donor-acceptor-π-acceptor D-A-π-A dyes having a medium to large size of the conjugated scaffold are evaluated, using the methods of the Density Functional Theory (DFT), in terms of free energy differences between their neutral and oxidized ground-state forms. These results are compared to the available experimental data and to the computed highest occupied molecular orbital energy −ε(HOMO) values as an approximation of ground-state redox potentials according to Koopmans’ theorem. Using the MPW1K functional in combination with the 6-31+G* basis set, the strategy based on the free energy cycle, including solvent effects, reproduces with a good level of accuracy the observed values (mean absolute error (MAE) < 0.2 eV) and trend of redox potentials within related families of dyes. On the other hand, the −ε(HOMO) values are only able to capture the experimental trends in redox potential values.
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Kim, Dooyoung, et Thomas S. Teets. « Strategies for accessing photosensitizers with extreme redox potentials ». Chemical Physics Reviews 3, no 2 (juin 2022) : 021302. http://dx.doi.org/10.1063/5.0084554.

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Photoredox catalysis has been prominent in many applications, including solar fuels, organic synthesis, and polymer chemistry. Photocatalytic activity directly depends on the photophysical and electrochemical properties of photocatalysts in both the ground state and excited state. Controlling those properties, therefore, is imperative to achieve the desired photocatalytic activity. Redox potential is one important factor that impacts both the thermodynamic and kinetic aspects of key elementary steps in photoredox catalysis. In many challenging reactions in organic synthesis, high redox potentials of the substrates hamper the reaction, leading to slow conversion. Thus, the development of photocatalysts with extreme redox potentials, accompanied by potent reducing or oxidizing power, is required to execute high-yielding thermodynamically demanding reactions. In this review, we will introduce strategies for accessing extreme redox potentials in photocatalytic transformations. These include molecular design strategies for preparing photosensitizers that are exceptionally strong ground-state or excited-state reductants or oxidants, highlighting both organic and metal-based photosensitizers. We also outline methodological approaches for accessing extreme redox potentials, using two-photon activation, or combined electrochemical/photochemical strategies to generate potent redox reagents from precursors that have milder potentials.
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Vlcek, A. A., Elaine S. Dodsworth, William J. Pietro et A. B. P. Lever. « Excited State Redox Potentials of Ruthenium Diimine Complexes ; Correlations with Ground State Redox Potentials and Ligand Parameters ». Inorganic Chemistry 34, no 7 (mars 1995) : 1906–13. http://dx.doi.org/10.1021/ic00111a043.

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Bednářová, Eva, Logan R. Beck, Tomislav Rovis, Samantha L. Goldschmid, Katherine Xie, Nicholas E. S. Tay, Benjamin D. Ravetz, Jun Li et Candice L. Joe. « Tuning the Electrochemical and Photophysical Properties of Osmium-Based Photoredox Catalysts ». Synlett 33, no 03 (14 janvier 2022) : 247–58. http://dx.doi.org/10.1055/s-0041-1737792.

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AbstractThe use of low-energy deep-red (DR) and near-infrared (NIR) light to excite chromophores enables catalysis to ensue across barriers such as materials and tissues. Herein, we report the detailed photophysical characterization of a library of OsII polypyridyl photosensitizers that absorb low-energy light. By tuning ligand scaffold and electron density, we access a range of synthetically useful excited state energies and redox potentials.1 Introduction1.1 Scope1.2 Measuring Ground-State Redox Potentials1.3 Measuring Photophysical Properties1.4 Synthesis of Osmium Complexes2 Properties of Osmium Complexes2.1 Redox Potentials of Os(L)2-Type Complexes2.2 Redox Potentials of Os(L)3-Type Complexes2.3 UV/Vis Absorption and Emission Spectroscopy3 Conclusions
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Medina, Edinson, et Balazs Pinter. « A DFT Study on the Redox Active Behavior of Carbene and Pyridine Ligands in the Oxidative and Reductive Quenching Cycles of Ruthenium Photoredox Catalysts ». Catalysts 10, no 1 (6 janvier 2020) : 80. http://dx.doi.org/10.3390/catal10010080.

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In this study, a detailed look at the electronic structure changes induced by photon absorption and of the succeeding redox events of the oxidative and reductive quenching cycles of ruthenium–carbene and ruthenium–pyridine photoredox catalysts is provided through an arsenal of density functional theory-based techniques including electron density difference Δρ(r) maps, spin-density distributions, and the non-covalent interaction analysis. We introduced an efficient computational protocol to obtain accurate equilibrium structures and ground-state reduction potentials for these types of complexes, substantiated via a direct comparison to empirical X-ray structures and cyclic voltammetry measurements, respectively. Moreover, we demonstrated the utility of a hitherto unexplored approach to compute excited-state redox potentials based on the Gibbs free energy of the triplet metal-to-ligand charge transfer state (3MLCT). The analyzed Δρ(r) maps revealed the characteristic features of, for example, metal- and ligand-centered reductions and oxidations in both ground and excited states and MLCT processes, disclosing the active participation of carbene ligands in the redox events of homoleptic systems. Beyond analyzing ligand–ligand non-covalent interactions and redox-active behaviors of carbene and pyridine ligands side by side, the effect of such groups on the kinetics of 3MLCT to 3MC transition was scrutinized.
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Hammond, Timothy G., Patricia L. Allen et Holly H. Birdsall. « Validation of Assays for Reactive Oxygen Species and Glutathione in Saccharomyces cerevisiae during Microgravity Simulation ». Gravitational and Space Research 3, no 2 (1 décembre 2015) : 42–53. http://dx.doi.org/10.2478/gsr-2015-0010.

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ABSTRACT The effects of spaceflight on yeast have high concordance with agents that induce a very low intracellular redox state and induce a massive efflux of glutathione. These results raise important issues. Can the reduced redox state during spaceflight be reproduced and modulated in ground-based simulations? Will this allow definition of unique drug pathways as a low redox potential state mirrors the electrophilic properties of mitochondria where many drugs are metabolized? Unfortunately, assays for redox status and its major cellular determinant—glutathione—are diverse and often cell-type-specific. Currently, an accepted redox probe set for yeast studies is not available. This paper validates fluorescent probes for glutathione and reactive oxygen status in yeast to support mechanistic studies of microgravity and drug metabolism. The plethora of fluorescent reagents for reactive oxygen species and glutathione makes head-to-head comparisons of all the alternatives impractical. These reagents measure the physiological milieu of reactive oxygen species and diverse thiols, rather than specific individual molecules. We report that in yeast, monochlorobimane (mBCL) and 2’,7’-dichlorodihydrofluorescein diacetate (DC-FDA) are suitable for fluorometric and flow cytometry studies of glutathione and reactive oxygen species, respectively. Both dyes have low background fluorescence, predictable loading, good retention, and are not acutely toxic to Saccharomyces cerevisiae. Both dyes show concordance with other fluorescent and biochemical assays of reactive oxygen species.
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Bourotte, Christine, Reginaldo Bertolo, Marta Almodovar et Ricardo Hirata. « Natural occurrence of hexavalent chromium in a sedimentary aquifer in Urânia, State of São Paulo, Brazil ». Anais da Academia Brasileira de Ciências 81, no 2 (juin 2009) : 227–42. http://dx.doi.org/10.1590/s0001-37652009000200009.

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Anomalous concentrations of hexavalent chromium have been detected in ground-water of the Adamantina Aquifer inat least 54 municipalities located in the northwestern region of the State of São Paulo, southeast Brazil, occasionallyexceeding the permitted limit for human consumption (0.05 mg.L-1). An investigation was conducted in the municipality of Urânia, where the highest concentrations of chromium were detected regionally. It was defined that the originof this contamination is natural, since high concentrations of chromium were detected in aquifer sandstones (averageof 221 ppm) and also in pyroxenes (6000 ppm), one of the main heavy minerals found in the sediments. Besides, noother possible diffuse or point sources of contamination were observed in the study area. Stratification of ground-waterquality was observed and the highest concentrations of Cr6+ were detected at the base of the aquifer (0.12 mg.L-1),where ground-water shows elevated values for redox potential (472.5 mV) and pH (8.61). The origin of Cr6+ in water may be associated with the weathering of pyroxene (augite), followed by the oxidation of Cr3+ by manganese oxides. The highest concentrations of Cr6+ are probably related to desorption reactions, due to the anomalous alkaline pHfound in ground-water at the base of the aquifer.
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Creutz, Carol, et Mei H. Chou. « Solvent Dependence of the Reduction Potential of Ground- and Excited-State Redox Couples : trans- Dioxo(1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane)osmium(VI/V) ». Inorganic Chemistry 33, no 14 (juillet 1994) : 3199–200. http://dx.doi.org/10.1021/ic00092a033.

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Bumpus, Peter B., et Sarah E. Kruse. « Self-potential monitoring for hydrologic investigations in urban covered-karst terrain ». GEOPHYSICS 79, no 6 (1 novembre 2014) : B231—B242. http://dx.doi.org/10.1190/geo2013-0354.1.

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In the covered karst of west-central Florida, USA, sinkholes (sandy collapse conduits) provide locally concentrated recharge to underlying aquifers. For water management, it would be beneficial to understand the rates at which collapse conduits recharge an underlying aquifer. Self-potential (SP) monitoring has promise as a noninvasive, relatively low-cost method for assessing temporal variability in flow. Previous studies suggested that negative SP anomalies over collapse conduits correspond to downward-flowing groundwater; however, before SP surveys can be reliable indicators of conduit flow, SP from ET, soil conductivity changes, redox, electrode effects, and cultural noise must be better understood. A year of continuous SP monitoring with two grids of approximately 15 Pb/PbCl/KCl nonpolarizing electrodes each was combined with high-resolution ground-penetrating radar surveys and intermittent water table monitoring over two small covered-karst conduits in Tampa, Florida, USA. Although variations in SP resulting from changes in cultural noise, soil conductivity, ET, redox, and rainfall were evident, separate and unrelated positive and negative SP anomalies episodically manifested over conduits, which suggested that conduit flow could be dynamic, not static. Three flow regimes in conduits were postulated: conduit permeability higher than in surrounding surficial sediments, conduit permeability lower than in surrounding surface sediments, conduit permeability matched surrounding surface sediments. Numerical steady-state 2D simulations in Comsol created the three postulated flow regimes and revealed that a different SP polarity could result from different rates of flow: positive SP corresponded to higher permeability conduits, negative SP corresponded to lower permeability conduits, no or minimal SP appeared when conduits and surrounding sediments had equal permeability. In these models, downward flow was not responsible for generating negative SP. To assess the hydrology of a conduit, it appears that SP should be monitored continuously. Further monitoring of field sites with hydrologic sensors is needed.
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Yang, Jing, John H. Enemark et Martin L. Kirk. « Metal–Dithiolene Bonding Contributions to Pyranopterin Molybdenum Enzyme Reactivity ». Inorganics 8, no 3 (5 mars 2020) : 19. http://dx.doi.org/10.3390/inorganics8030019.

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Here we highlight past work on metal–dithiolene interactions and how the unique electronic structure of the metal–dithiolene unit contributes to both the oxidative and reductive half reactions in pyranopterin molybdenum and tungsten enzymes. The metallodithiolene electronic structures detailed here were interrogated using multiple ground and excited state spectroscopic probes on the enzymes and their small molecule analogs. The spectroscopic results have been interpreted in the context of bonding and spectroscopic calculations, and the pseudo-Jahn–Teller effect. The dithiolene is a unique ligand with respect to its redox active nature, electronic synergy with the pyranopterin component of the molybdenum cofactor, and the ability to undergo chelate ring distortions that control covalency, reduction potential, and reactivity in pyranopterin molybdenum and tungsten enzymes.
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Thèses sur le sujet "Ground state redox potential"

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Yagi, Masaki. « Derivation of ground-state female ES cells maintaining gamete-derived DNA methylation ». Kyoto University, 2018. http://hdl.handle.net/2433/232300.

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Hou, Jue. « Characterizing Breast Cancer Invasive Potential Using Combined Label-Free Multiphoton Metabolic Imaging of Cellular Lipids and Redox State ». Thesis, University of California, Irvine, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10288401.

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Aerobic glycolysis (Warburg effect) is accompanied by significant alterations in cellular redox state and constitutes one of the hallmarks of cancer cell metabolism. Label-free multi-photon microscopy (MPM) methods based on two-photon excited fluorescence (TPEF) have been used extensively to form high-resolution images of redox state in cells and tissues based on intrinsic NADH and FAD+ fluorescence. However, changes in cellular redox alone are insufficient to fully characterize cancer metabolism and predict invasive potential. We demonstrate that label-free MPM measurements of TPEF-derived redox state (optical redox ratio, ORR = FAD+/(FAD + NADH)) combined with coherent Raman imaging of lipid formation can be used to quantitatively characterize cancer cells and their relative invasive potential. In addition, we confirm, using coherent Raman and deuterium labeling methods, that glucose is a significant source for the cellular synthesis of lipid biomass in glycolytic breast cancer cells. Live cell metabolism was imaged in 3D models of primary mammary epithelial cells (PME) and 2 cancer cell lines, T47D and MDA-MB-231. While we observed overlap in the distribution of the optical redox ratio between these different cell lines, the combination of ORR and lipid volume fraction derived from coherent Raman signals provided complementary independent measures and clear separation. Furthermore, we observed an increase in both lipid synthesis and consumption rates in E2-treated T47D cancer cells cultured in deuterated glucose by tracking the formation and disappearance of deuterated lipids. These results suggest that due to the relatively wide range of ORR values that reflect the natural diversity of breast cancer cellular redox states, the addition of lipid signatures obtained from coherent Raman imaging can improve our ability to characterize and understand key metabolic features that are hallmarks of the disease.

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Sarkar, Deboleena Dipak. « Potential Role Of Endoplasmic Reticulum Redox Changes In Endoplasmic Reticulum Stress And Impaired Protein Folding In Obesity-Associated Insulin Resistance ». Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/306999.

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Endoplasmic reticulum (ER) stress plays an important role in the pathogenesis of obesity-related inflammation and insulin resistance in adipose tissue. However, the mechanisms responsible for induction of ER stress are presently unclear. Proper ER redox state is crucial for oxidative protein folding and secretion and impaired protein folding in ER leads to induction of unfolded protein response and ER stress. However, while ER redox state is more oxidizing compared to the rest of the cell, its regulation is poorly understood. In order to determine the effects of ER redox state on development of ER stress and insulin resistance, several fluorescence-based sensors have been developed. However, these sensors have yielded results that are inconsistent with each other and with earlier non-fluorescence-based studies. In this study we attempted to develop and characterize a sensitive tool to study the ER redox state in adipocytes in real-time by targeting a new generation of redox-sensitive green fluorescent protein (roGFP) to ER. The roGFP1-iL sensor targeted to the ER is termed ‘eroGFP1-iL’ by convention. The ER-targeting eroGFP1-iL construct contains the signal peptide from adiponectin and the ER retention motif KDEL and has a midpoint reduction potential of -229 mV in vitro in oxidized and reduced lipoic acid. Despite having a midpoint reduction potential that is 50 mV higher than the previously determined midpoint reduction potential of the ER, eroGFP1-iL was found capable of detecting both oxidizing and reducing changes in the ER. In an attempt to determine the mechanisms by which roGFP1-iL detects oxidizing changes, we found that, first, glutathione mediated the formation of disulfide-bonded roGFP1-iL dimers with an intermediate excitation fluorescence spectrum resembling a mixture of oxidized and reduced monomers. Second, glutathione facilitated dimerization of roGFP1-iL, which in effect shifted the equilibrium from oxidized monomers to dimers, thereby increasing the molecule’s reduction potential compared with a dithiol redox buffer like lipoic acid. From this study, we concluded that the glutathione redox couple in ER significantly raised the reduction potential of roGFP1-iL in vivo by facilitating its dimerization while preserving its ratiometric nature, which makes it suitable for monitoring oxidizing and reducing changes in ER with high reliability in real-time. The ability of roGFP1-iL to detect both oxidizing and reducing changes in ER and its dynamic response in glutathione redox buffer between approximately -190 and -130 mV in vitro suggest a range of ER redox potential consistent with those determined by earlier approaches that did not involve fluorescent sensors. Our primary aim in developing eroGFP1-iL as a redox-sensing tool was to be able to assess whether redox changes represent an early initiator of ER stress in obesity-induced reduction in high molecular weight (HMW) adiponectin in circulation. Hypoxia is a known mediator of redox changes. We found that oligomerization of HMW adiponectin was impaired in the hypoxic conditions observed in differentiated fat cells. The redox-active antioxidant ascorbate was found capable of reversing hypoxia-induced ER stress. Lastly, we demonstrated that changes in ER redox condition is associated with ER stress response and is implicated in the mechanism of action of the insulin-sensitizing agent troglitazone and desensitizing agent palmitate. Using the redox sensing property of eroGFP1-iL, palmitate was found to be an effective modulator of redox changes in the ER and troglitazone was found to cause oxidizing changes in the ER. The action of palmitate in causing aberrant ER redox conditions was associated with aberrant HMW adiponectin multimerization. Palmitate-induced ER stress was ameliorated by troglitazone. Taken together, the data suggest a potential role of ER redox changes in ER stress and impaired protein folding in adipocytes.
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Yang, Juan. « Spectroscopic investigations of the vibrational potential energy surfaces in electronic ground and excited states ». Diss., Texas A&M University, 2003. http://hdl.handle.net/1969.1/5900.

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The vibrational potential energy surfaces in electronic ground and excited states of several ring molecules were investigated using several different spectroscopic methods, including far-infrared (IR), Raman, ultraviolet (UV) absorption, fluorescence excitation (FES), and single vibronic level fluorescence (SVLF) spectroscopies. Based on new information obtained from SVLF and millimeter wave spectra, the far-IR spectra of coumaran were reassigned and the one-dimensional ring-puckering potential energy functions for several vibrational states in the S0 ground state were determined. The barrier was found to be 154 cm-1 and the puckering angles to be ± 25°, in good agreement with the millimeter wave barrier of 152 cm-1 and puckering angles of ± 23°. Moreover, the UV absorption and FES spectra of coumaran allowed the one-dimensional ring-puckering potential energy functions in the S1 excited state to be determined. The puckering barrier is 34 cm-1 for the excited state and the puckering angles are ± 14°. Several calculations with different basis sets have been carried out to better understand the unusual vibrational frequencies of cyclopropenone. It was shown that there is strong interaction between the C=O and symmetric C-C stretching vibrations. These results differ quantitatively from a previous normal coordinate calculation and interpretation. The vapor-phase Raman spectrum of 3,7-dioxabicyclo[3.3.0]oct-1,5-ene was analyzed and compared to the predicted spectrum from DFT calculations. The spectrum further shows it has D2h symmetry, in which the skeletons of both rings are planar. The infrared and Raman spectra of vapor-phase and liquid-phase 1,4-benzodioxan and 1,2,3,4-tetrahydronaphthalene were collected and the complete vibrational assignments for both molecules were made. Theoretical calculations predicted the barriers to planarity to be 4809 cm-1 for 1,2,3,4-tetrahydonaphthalene and 4095 cm-1 for 1,4-benzodioxan. The UV absorption, FES, and SVLF spectra of both molecules were recorded and assigned. Both one and two-dimensional potential energy functions of 1,4-benzodioxan for the ring-twisting and ring-bending vibrations were carried out for the S0 and S1(π,π*) states, and these were consistent with the high barriers calculated for both states. The low-frequency spectra of 1,2,3,4-tetrahydronaphthalene in both S0 and S1(π,π*) states were also analyzed.
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Ardila, Alex Javier Hernandez. « Estabilidade de ground state para a equação de Schrödinger logarítmica com potenciais do tipo delta ». Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/45/45131/tde-29082016-175729/.

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Na primeira parte do trabalho estudamos a equação de Schrödinger logarítmica com um delta potencial; $V(x)=-\\gamma \\,\\delta(x)$, onde $\\delta$ é a distribuição de Dirac na origem e o parâmetro real $\\gamma$ descreve a intensidade do potencial. Estabelecemos a existência e unicidade das soluções do problema de Cauchy associado em um espaço de funções adequado. No caso do potencial atrativo ($\\gamma>0$), calculamos de forma explícita o seu único ground state e mostramos a sua estabilidade orbital.\\\\ A segunda parte trata detalhadamente da equação de Schrödinger logarítmica com um delta derivada potencial; $V(x)=-\\gamma\\, \\delta^{\\prime}(x)$. A boa colocação global para o problema de Cauchy é verificada em um espaço de funções adequado. No caso do potencial atrativo ($\\gamma>0$), o conjunto dos ground states é completamente determinado. Mais precisamente: se $0<\\gamma\\leq2$, então há um único ground state e é uma função ímpar; se $\\gamma>2$, então existem dois ground states não-simétricos. Em adição, provamos que cada ground state é orbitalmente estável através de uma abordagem variacional. Finalmente, usando a teoria de extensão de operadores simétricos, também mostramos um resultado de instabilidade para $\\gamma>2$.
The first part of this thesis deals with the logarithmic Schrödinger equation with a delta potential; $V(x)=-\\gamma \\,\\delta(x)$, where $\\delta$ is the Dirac distribution at the origin and the real parameter $\\gamma$ is interpreted as the strength of the potential. We establish the existence and uniqueness of the solutions of the associated Cauchy problem in a suitable functional framework. In the attractive potential case ($\\gamma>0$), we explicitly compute the unique ground state and we show their orbital stability .\\\\ The second part deals with the case of the logarithmic Schrödinger equation with a delta prime potential; $V(x)=-\\gamma\\, \\delta^{\\prime}(x)$. Global well-posedness is verified for the Cauchy problem in a suitable functional space. In the attractive potential case ($\\gamma>0$), the set of the ground state is completely determined. More precisely: if $0<\\gamma\\leq2$, then there is a single ground state and it is an odd function; if $\\gamma>2$, then there exist two non-symmetric ground states. Moreover, we show that every ground state is orbitally stable via a variational approach. Finally, by applying the theory of extensions of symetric operators, we also prove a result of instability for $\\gamma>2$.
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at, rseiring@ap univie ac. « On the Ordering of Energy Levels in Homogeneous Magnetic Fields ». Lett. Math. Phys. 54 (2000) 213-226, 2000. ftp://ftp.esi.ac.at/pub/Preprints/esi959.ps.

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Yang, Kai. « Dynamics of the energy critical nonlinear Schrödinger equation with inverse square potential ». Diss., University of Iowa, 2017. https://ir.uiowa.edu/etd/5685.

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We consider the Cauchy problem for the focusing energy critical NLS with inverse square potential. The energy of the solution, which consists of the kinetic energy and potential energy, is conserved for all time. Due to the focusing nature, solution with arbitrary energy may exhibit various behaviors: it could exist globally and scatter like a free evolution, persist like a solitary wave, blow up at finite time, or even have mixed behaviors. Our goal in this thesis is to fully characterize the solution when the energy is below or at the level of the energy of the ground state solution $W_a$. Our main result contains two parts. First, we prove that when the energy and kinetic energy of the initial data are less than those of the ground state solution, the solution exists globally and scatters. Second, we show a rigidity result at the level of ground state solution. We prove that among all solutions with the same energy as the ground state solution, there are only two (up to symmetries) solutions $W_a^+, W_a^-$ that are exponential close to $W_a$ and serve as the threshold of scattering and blow-up. All solutions with the same energy will blow up both forward and backward in time if they go beyond the upper threshold $W_a^+$; all solutions with the same energy will scatter both forward and backward in time if they fall below the lower threshold $W_a^-$. In the case of NLS with no potential, this type of results was first obtained by Kenig-Merle \cite{R: Kenig focusing} and Duyckaerts-Merle \cite{R: D Merle}. However, as the potential has the same scaling as $\Delta$, one can not expect to extend their results in a simple perturbative way. We develop crucial spectral estimates for the operator $-\Delta+a/|x|^2$, we also rely heavily on the recent understanding of the operator $-\Delta+a/|x|^2$ in \cite{R: Harmonic inverse KMVZZ}.
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Duranti, Mattia. « Bromine-Based Electrolyte Properties for a Semi-Organic Redox Flow Battery ». Doctoral thesis, Università ; degli studi di Trento, 2020. http://hdl.handle.net/11572/276465.

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Redox Flow Batteries are chemical based energy storage systems that accumulate energy in liquid electrolytes. Dissolved redox active substances undergo redox reactions in an electrochemical cell and so charge and discharge a battery. Recently, the introduction of organic materials as electrolytes raised research interest. Electrolytes that operate with the bromine/bromide redox couple are interesting due to their high energy density and fast reversible kinetics. They are used in combination with several anodic chemistries (e.g. Zinc, Hydrogen, Quinone), including organic materials.Due to the corrosive and volatile nature of bromine, practical electrolytes use Bromine Complexing Agents (BCAs) in order to bind bromine in a less volatile form and deal with safety issues. These additives have a strong influence on the battery’s operation by influencing the concentration of redox active species, the cell voltage and the electrolyte conductivity. Nevertheless, very little is known about the real properties of aqueous acidic bromine electrolytes, both in pure dilution and in presence of BCAs, which influence on the electrolyte is not predictable so far. The aim of this PhD project is to provide a comprehensive understanding of the behavior of an electrolyte based on bromine and bromide, with particular reference to the one used in semi-organic flow batteries. Along this work an analysis on the performance of a AQDS-Bromine flow battery cell was executed and an extensive study on the physico-chemical behavior of the positive electrolyte was developed. A review of the flow battery technology and of the metrics and methods available for diagnostics was firstly performed as a basis to define macro characteristics,such as State of Charge (SoC) and State of Health (SoH). The cycling behavior of an AQDS-Bromine flow battery was investigated by cell tests and possible degradation mechanisms have been highlighted and explained by interpretation of electrochemical measurements. Following, a broad characterization of the bromine-based electrolyte was performed, producing extended experimental data on physico-chemical properties and a modeling framework for the prediction of the electrolyte behavior.
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Pittayakanchit, Weerapat. « The Global Stability of the Solution to the Morse Potential in a Catastrophic Regime ». Scholarship @ Claremont, 2016. http://scholarship.claremont.edu/hmc_theses/72.

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Swarms of animals exhibit aggregations whose behavior is a challenge for mathematicians to understand. We analyze this behavior numerically and analytically by using the pairwise interaction model known as the Morse potential. Our goal is to prove the global stability of the candidate local minimizer in 1D found in A Primer of Swarm Equilibria. Using the calculus of variations and eigenvalues analysis, we conclude that the candidate local minimizer is a global minimum with respect to all solution smaller than its support. In addition, we manage to extend the global stability condition to any solutions whose support has a single component. We are still examining the local minimizers with multiple components to determine whether the candidate solution is the minimum-energy configuration.
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Mohammadpourasl, Sanaz, Adalgisa Sinicropi et Maria Laura Parisi. « Design and characterization by using computational methodologies and life cycle assessment (LCA) of devices for energy production from renewable energy sources ». Doctoral thesis, 2020. http://hdl.handle.net/2158/1202001.

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This thesis focuses on the design and characterization of more efficient components for Dye-Sensitized Solar Cells (DSSCs), an example of innovative latest generation photovoltaic systems. DSSCs are considered as a promising alternative to silicon solar cells due to their low cost, flexibility, and facile fabrication. However, a low photo-electric conversion efficiency and stability of these cells are the main obstacles for their large-scale commercial applications. An emerging challenge is to find an optimum set of materials to improve the performance of DSSCs. One of the key components to optimize is the light absorbing dye (also referred as sensitizer) that is employed to enhance light harvesting of TiO2 nanoparticles. Indeed, sensitizers are responsible for DSSCs photovoltaic performances, transparency and color. Another scope of this thesis is the assessment of the environmental performances connected with the fabrication of DSSCs components, namely the sensitizer, through the application of the Life Cycle Assessment (LCA) methodology. Indeed, to evaluate the sustainability of photovoltaic devices, the investigation of the environmental impacts generated during their fabrication is essential in order to improve and optimize the energy and resource efficiency of manufacturing processes and, ultimately, the environmental footprint of the device.
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Livres sur le sujet "Ground state redox potential"

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Ltd, Gujarat Water Resources Development Corporation. Report on estimation of ground water resources and irrigation potential in Gujarat State, GWRE-2002. Gandhinagar, Gujarat : Narmada Water Resources, Water Supply and Kalpsar Dept., Govt. of Gujarat, 2004.

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Stallcop, James R. Ab initio potential-energy surfaces and electron-spin-exchange cross sections for H-O₂ interactions. [Washington, DC : National Aeronautics and Space Administration, 1996.

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Stallcop, James R. Ab initio potential-energy surfaces and electron-spin-exchange cross sections for H-O₂ interactions. [Washington, DC : National Aeronautics and Space Administration, 1996.

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Harry, Partridge, Levin Eugene et United States. National Aeronautics and Space Administration., dir. Ab initio potential-energy surfaces and electron-spin-exchange cross sections for H-O₂ interactions. [Washington, DC : National Aeronautics and Space Administration, 1996.

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E, Bishop Charles. Potential for potable ground water on state land near Canyonlands National Park, Utah, section 16, T. 30 S., R. 20 E. [Salt Lake City, Utah] : Utah Geological Survey, 1996.

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Moving America, new directions, new opportunities : Assessment of the potential for magnetic levitation transportation systems in the United States : a report to Congress. [Washington, D.C.?] : U.S. Dept. of Transportation, Federal Railroad Administration, 1990.

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New Jersey. Legislature. General Assembly. Special Committee to Investigate Hazardous Waste Disposal at Military Institutions. Public hearing before Special Committee to Investigate Hazardous Waste Disposal at Military Institutions on potential sources of ground water contamination posed by hazardous waste disposal at the Lakehurst Naval Air Engineering Center, October 10, 1985, Room 346, State House Annex, Trenton, New Jersey. [Trenton : The Committee, 1985.

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Potential for potable ground water on state land near Canyonlands National Park, Utah, section 16, T. 30 S., R. 20 E. Utah Geological Survey, 1996. http://dx.doi.org/10.34191/ri-230.

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Surya, Deva. Part VI Rights—Structure and Scope, Ch.35 Saving Clauses : the Ninth Schedule and Articles 31A–C. Oxford University Press, 2016. http://dx.doi.org/10.1093/law/9780198704898.003.0035.

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This chapter examines the drafting history, nature, scope, (mis)use, and relevance of the so-called ‘saving clauses’ of the Indian Constitution: Article 31A, Article 31B read with the Ninth Schedule, and Article 31C. They are designed to protect laws aimed at agrarian reforms or at implementing certain Directive Principles of State Policy (DPSPs) from a potential constitutional challenge on the ground of violating fundamental rights (FRs), andexceptionally allow certain laws to override FRs. This chapter offers an alternative reading of the saving clauses and discusses the Ninth Schedule, arguing that, despite being misused in the past, it might not be abused in the future, and that the Basic Structure doctrine is inappropriate to test the validity of laws inserted in the Ninth Schedule. It also suggests that the judiciary misconstrued their role with respect to the right to property as a FR, as well as the value of DPSPs relative to FRs.
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Perrone, Nicolás M. Investment Treaties and the Legal Imagination. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780198862147.001.0001.

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Foreign investors have a privileged position under investment treaties. They enjoy strong rights, have no obligations, and can rely on a highly efficient enforcement mechanism: investor–state dispute settlement (ISDS). This extraordinary status has made international investment law one of the most controversial areas of the global economic order. Unsurprisingly, its origin and evolution have been the subject of a long debate. This book adds to the discussion by showing that foreign investor rights are not the result of unpredicted arbitral interpretations, but rather the likely outcome of a world-making project realized by a coalition of business leaders, bankers, and their lawyers in the 1950s and 1960s. Some initiatives that these norm entrepreneurs planned for did not concretize, such as a multilateral investment convention, but they were successful in developing a legal imagination that gradually occupied the space of international investment law. They sought not only to set up a dispute settlement mechanism but also to create a platform to ground their vision of foreign investment relations. Tracing their normative project from the post-World War II period, this book shows that the legal imagination of the norm entrepreneurs is remarkably similar to present ISDS practice. Common to both is what they protect—such as foreign investors’ legitimate expectations—as well as what they silence or make invisible. Our canon of imagination, of adjustment and potential reform, remains closely associated with the world-making project of the norm entrepreneurs of the 1950s and 1960s.
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Chapitres de livres sur le sujet "Ground state redox potential"

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Wagner, E., J. T. P. Abrechtová, J. Normann et H. Greppin. « Redox state and phosphorylation potential as macroparameters in rhythmic control of metabolism — a molecular basis for seasonal adaptation of development ». Dans The Redox State and Circadian Rhythms, 257–77. Dordrecht : Springer Netherlands, 2000. http://dx.doi.org/10.1007/978-94-015-9556-8_14.

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Wang, Yue, Qingling Li, Guoqing Liu, Wenhao Gong, Shijun Yu, Yu Liu, Xiaozhou Dong, Shiwen Chen et Chengwen Zhang. « The Ground-State Potential Energy Surface of F-Li2 Polymer ». Dans Proceeding of 2021 International Conference on Wireless Communications, Networking and Applications, 1108–13. Singapore : Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-2456-9_111.

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AbstractThe first three-dimensional potential energy surface (PES) for the ground-state of F-Li2 polymer by CCSD(T) method were present. Two Jacobi coordinates, R and θ and the frozen molecular equilibrium geometries were used. We mixed basis sets aug-cc-pCVQZ for the Li atom and aug-cc-pCVDZ for the F atom, with an additional (3s3p2d) set of midbond functions. The total of about 365 points were generated for the PES. Our ab initio calculations were consistent with the experimental data very well.
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Wada, Yasuaki. « The Redox State of Serum Albumin as a Potential Protein Nutrition Biomarker ». Dans Biomarkers in Disease : Methods, Discoveries and Applications, 47–66. Cham : Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-07389-2_3.

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Wada, Yasuaki. « The Redox State of Serum Albumin as a Potential Protein Nutrition Biomarker ». Dans Biomarkers in Disease : Methods, Discoveries and Applications, 1–20. Cham : Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-81304-8_3-1.

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Davidson, Sean M., Derek Yellon et Michael R. Duchen. « Assessing Mitochondrial Potential, Calcium, and Redox State in Isolated Mammalian Cells Using Confocal Microscopy ». Dans Methods in Molecular Biology, 421–30. Totowa, NJ : Humana Press, 2007. http://dx.doi.org/10.1007/978-1-59745-365-3_30.

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Guelachvili, Guy, et Nathalie Picqué. « 16O3 Effective Potential Energy Function Parameters for the Ground Electronic State. Equilibrium Structure ». Dans Molecular Constants Mostly from Infrared Spectroscopy, 167–68. Berlin, Heidelberg : Springer Berlin Heidelberg, 2019. http://dx.doi.org/10.1007/978-3-662-57960-2_89.

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Hamano, Masaru, et Masahiro Ikeda. « Characterization of the Ground State to the Intercritical NLS with a Linear Potential by the Virial Functional ». Dans Trends in Mathematics, 279–307. Cham : Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-58215-9_12.

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Guelachvili, Guy, et Nathalie Picqué. « 16O3 Empirical Potential Energy Surface Pot II, Using an EKE Operator. Parameters for the Ground Electronic State ». Dans Molecular Constants Mostly from Infrared Spectroscopy, 175–76. Berlin, Heidelberg : Springer Berlin Heidelberg, 2019. http://dx.doi.org/10.1007/978-3-662-57960-2_92.

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Ermler, Walter C., Bruce J. Rosenberg et Isaiah Shavitt. « Ab Initio SCF and CI Studies on the Ground State of the Water Molecule. III. Vibrational Analysis of Potential Energy and Property Surfaces ». Dans Comparison of Ab Initio Quantum Chemistry with Experiment for Small Molecules, 171–215. Dordrecht : Springer Netherlands, 1985. http://dx.doi.org/10.1007/978-94-009-5474-8_7.

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van der Burg, Martijn. « Subprefects : (Trans)Regional Tools of Integration ? » Dans Napoleonic Governance in the Netherlands and Northwest Germany, 123–46. Cham : Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-66658-3_6.

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AbstractThis chapter examines the Napoleonic subprefects who have been in office in the Netherlands and Northwest Germany. Within the prefectoral system, these sous-préfets were the highest officials at arrondissement (disctrict) level. Activities of subprefects, somewhat neglected by historians, give insight into how French tried to rally the locals, and how this affected the daily functioning of the Empire. Discussed are subprefects’ sociocultural backgrounds, imperial careers, and perception of Napoleonic governance. Subprefects had to balance national, local, and personal interest. Integration at district level was hard when the letter of the administrative legislation and the precise instructions from above were rigidly adhered to. Subprefects traveling the Empire linked events in the Netherlands and Northwest Germany to developments elsewhere, promoting integration into the Empire. Circulation patterns reflect different ideas on the required level of integration. It is argued that the figure of the subprefect was a potential ‘tool of integration’. That subprefects were close to the ground could contributed to the effectiveness of Napoleonic governance. But subprefects also coped with demanding prefects, and interference of other agents of the central state. Reversely, unwilling subprefects were in a position to hinder the integration process.
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Actes de conférences sur le sujet "Ground state redox potential"

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Ishihara, H., K. Niitsu et K. Nakazato. « DNA Single Base Polymerization Detection Using CMOS FET-Based Redox Potential Sensor Array ». Dans 2014 International Conference on Solid State Devices and Materials. The Japan Society of Applied Physics, 2014. http://dx.doi.org/10.7567/ssdm.2014.d-6-1.

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Park, Y. H., et I. Hijazi. « Ground State Structure of Cu Nanoclusters ». Dans ASME 2011 Pressure Vessels and Piping Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/pvp2011-57748.

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The study of metal clusters has attracted much attention in recent years. Noble metal nanoparticles are of particular interest since their chemical, thermodynamic, electronic, and optical properties make them interesting candidates as building blocks of nanostructure materials. Delineation of these properties requires a complete and definitive characterization of the cluster’s geometrical structure. To find the ground state structure for a cluster, the potential-energy surface (PES) needs to be searched. In this paper, we proposed an efficient hierarchical search method to determine a ground state structure of copper clusters using an effective Monte Carlo simulated annealing method, which employs the Aggregate-Volume-Bias Monte Carlo (AVBMC) algorithm. Incorporated in the Monte Carlo method, is an efficient Embedded Atom Method (EAM) potential developed by the authors.
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Ma’arif, M., S. Faniandari, A. Suparmi, C. Cari et N. A. Pambudi. « Tsallis entropy of ground state classical cosmic string framework with DRSCO potential ». Dans INTERNATIONAL CONFERENCE ON SCIENCE AND APPLIED SCIENCE (ICSAS) 2019. AIP Publishing, 2019. http://dx.doi.org/10.1063/1.5141645.

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Radi, Peter, Christophe Gourlaouen, Roberto Marquardt, Gregor Knopp, Qiang Zhang, Martin Beck et Peter Bornhauser. « POTENTIAL CURVE OF GROUND STATE Cu2 UP TO 98% OF THE DISSOCIATION ENERGY ». Dans 2020 International Symposium on Molecular Spectroscopy. Urbana, Illinois : University of Illinois at Urbana-Champaign, 2020. http://dx.doi.org/10.15278/isms.2020.fd01.

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Dagenais, M., et W. F. Sharfin. « Stark Effect on a Ground State Exciton Confined in Three Dimensions ». Dans Optical Bistability. Washington, D.C. : Optica Publishing Group, 1988. http://dx.doi.org/10.1364/obi.1988.fa.5.

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We report the first measurement of the quadratic Stark shift of the bound exciton ground state (D°X) in the direct gap CdS semiconductor. The exciton is confined in three dimensions by the potential of a neutral donor (Li or Na interstitials) which restricts the exciton motion over dimensions of order of the free exciton Bohr radius (30 Å). Optical transmission measurements with a single mode dye laser reveal a very narrow linewidth (8-10 GHz) which implies a very well defined and reproducible potential well. This is in sharp contrast to previous realizations of three dimensional excitonic confinement where linewidths about 1000 times larger are commonly observed because of the large variations of the potential dimensions. At an electric field of 2.5 x 104 V/cm, a shift of the bound exciton resonance as large as its half-width at half-height is observed without any appreciable broadening of the resonance. The bound exciton shift is about 25 times smaller than the free exciton Stark shift measured in the same experimental conditions.
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Saji, Genn. « Radiation-Induced Electrolytic Corrosion of LWRS : (Part 2) — Verification of In- and Out-Core Redox Potential Differences ». Dans 2016 24th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/icone24-60895.

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The author recently identified that there should exist a “differential radiation cell” mechanism in the reactor water, prompting “radiation-induced electrolytic (RIE)” phenomena. This mechanism was identified while trying to theoretically reconstruct the potential differences observed in two in-pile test loops; NRI-Rez in Czech Republic and INCA Loop in Sweden. Part 2 of this series focuses on the theoretical reconstruction of the observed potential differences. Assuming a state of equilibrium, the author tried to develop a formalism by extending the Nernst equation to reproduce the observed redox potential differences. The radiological potential shift term is separated from the Nernst equation where the latter deals only with stable molecular and ionic species. The radiological effect is described as a perturbation term to the Nernst equation representing a potential shift due to radiation-chemical reactions which should diminish to zero without radiation. The theory generally reproduced the experimental results after fitting the theoretical curve at a single point of the potential for both PWR and BWR-NWC water chemistry environments. This discrepancy is likely due to the “conductive-dielectric property” of the reactor water.
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Ndengue, Steve, Tucker Carrington, Xiao-Gang Wang et Richard Dawes. « VIBRATIONAL LEVELS AND RESONANCES ON A NEW POTENTIAL ENERGY SURFACE FOR THE GROUND ELECTRONIC STATE OF OZONE ». Dans 69th International Symposium on Molecular Spectroscopy. Urbana, Illinois : University of Illinois at Urbana-Champaign, 2014. http://dx.doi.org/10.15278/isms.2014.mh12.

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Bruckmeier, R., H. Figger et C. Wunderlich. « Experimental evidence for the double-sheetedness of the ground state potential surface of H3 from its uv spectra ». Dans The XIth International conference on laser spectroscopy. AIP, 1993. http://dx.doi.org/10.1063/1.45041.

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Angraini, Lily Masyari, I. Wayan Sudiarta, I. G. N. Yudi Handayana et Marzuki. « Application of diffusion Monte Carlo method to obtain the ground state of a particle in a double well potential ». Dans THE 8TH NATIONAL PHYSICS SEMINAR 2019. AIP Publishing, 2019. http://dx.doi.org/10.1063/1.5132666.

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Roston, G. D., et M. S. Helmi. « On the validity of different intercombination rules for the parameters of the ground state (X[sup 1]O[sup +]) potential ». Dans The 13th international conference on spectral line shapes. AIP, 1997. http://dx.doi.org/10.1063/1.51850.

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Rapports d'organisations sur le sujet "Ground state redox potential"

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Banin, Amos, Joseph Stucki et Joel Kostka. Redox Processes in Soils Irrigated with Reclaimed Sewage Effluents : Field Cycles and Basic Mechanism. United States Department of Agriculture, juillet 2004. http://dx.doi.org/10.32747/2004.7695870.bard.

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The overall objectives of the project were: (a) To measure and study in situ the effect of irrigation with reclaimed sewage effluents on redox processes and related chemical dynamics in soil profiles of agricultural fields. (b) To study under controlled conditions the kinetics and equilibrium states of selected processes that affect redox conditions in field soils or that are effected by them. Specifically, these include the effects on heavy metals sorption and desorption, and the effect on pesticide degradation. On the basis of the initial results from the field study, increased effort was devoted to clarifying and quantifying the effects of plants and water regime on the soil's redox potential while the study of heavy metals sorption was limited. The use of reclaimed sewage effluents as agricultural irrigation water is increasing at a significant rate. The relatively high levels of suspended and, especially, dissolved organic matter and nitrogen in effluents may affect the redox regime in field soils irrigated with them. In turn, the changes in redox regime may affect, among other parameters, the organic matter and nitrogen dynamics of the root zone and trace organic decomposition processes. Detailed data of the redox potential regime in field plots is lacking, and the detailed mechanisms of its control are obscure and not quantified. The study established the feasibility of long-term, non-disturbing monitoring of redox potential regime in field soils. This may enable to manage soil redox under conditions of continued inputs of wastewater. The importance of controlling the degree of wastewater treatment, particularly of adding ultrafiltration steps and/or tertiary treatment, may be assessed based on these and similar results. Low redox potential was measured in a field site (Site A, KibutzGivat Brenner), that has been irrigated with effluents for 30 years and was used for 15 years for continuous commercial sod production. A permanently reduced horizon (Time weighted averaged pe= 0.33±3.0) was found in this site at the 15 cm depth throughout the measurement period of 10 months. A drastic cultivation intervention, involving prolonged drying and deep plowing operations may be required to reclaim such soils. Site B, characterized by a loamy texture, irrigated with tap water for about 20 years was oxidized (Time weighted average pe=8.1±1.0) throughout the measurement period. Iron in the solid phases of the Givat Brenner soils is chemically-reduced by irrigation. Reduced Fe in these soils causes a change in reactivity toward the pesticide oxamyl, which has been determined to be both cytotoxic and genotoxic to mammalian cells. Reaction of oxamyl with reduced-Fe clay minerals dramatically decreases its cytotoxicity and genotoxicity to mammalian cells. Some other pesticides are affected in the same manner, whereas others are affected in the opposite direction (become more cyto- and genotoxic). Iron-reducing bacteria (FeRB) are abundant in the Givat Brenner soils. FeRB are capable of coupling the oxidation of small molecular weight carbon compounds (fermentation products) to the respiration of iron under anoxic conditions, such as those that occur under flooded soil conditions. FeRB from these soils utilize a variety of Fe forms, including Fe-containing clay minerals, as the sole electron acceptor. Daily cycles of the soil redox potential were discovered and documented in controlled-conditions lysimeter experiments. In the oxic range (pe=12-8) soil redox potential cycling is attributed to the effect of the daily temperature cycle on the equilibrium constant of the oxygenation reaction of H⁺ to form H₂O, and is observed under both effluent and freshwater irrigation. The presence of plants affects considerably the redox potential regime of soils. Redox potential cycling coupled to the irrigation cycles is observed when the soil becomes anoxic and the redox potential is controlled by the Fe(III)/Fe(II) redox couple. This is particularly seen when plants are grown. Re-oxidation of the soil after soil drying at the end of an irrigation cycle is affected to some degree by the water quality. Surprisingly, the results suggest that under certain conditions recovery is less pronounced in the freshwater irrigated soils.
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Dai, Hai-Lung. (Dynamics of vibrationally excited polyatomic molecules and their unstable isomers on the electronic ground state potential surface) : Progress report. Office of Scientific and Technical Information (OSTI), janvier 1989. http://dx.doi.org/10.2172/6048251.

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Dickman, Martin B., et Oded Yarden. Genetic and chemical intervention in ROS signaling pathways affecting development and pathogenicity of Sclerotinia sclerotiorum. United States Department of Agriculture, juillet 2015. http://dx.doi.org/10.32747/2015.7699866.bard.

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Abstract: The long-term goals of our research are to understand the regulation of sclerotial development and pathogenicity in S. sclerotior11111. The focus in this project was on the elucidation of the signaling events and environmental cues involved in the regulation of these processes, utilizing and continuously developing tools our research groups have established and/or adapted for analysis of S. sclerotiorum, Our stated objectives: To take advantage of the recent conceptual (ROS/PPs signaling) and technical (amenability of S. sclerotiorumto manipulations coupled with chemical genomics and next generation sequencing) developments to address and extend our fundamental and potentially applicable knowledge of the following questions concerning the involvement of REDOX signaling and protein dephosphorylation in the regulation of hyphal/sclerotial development and pathogenicity of S. sclerotiorum: (i) How do defects in genes involved in ROS signaling affect S. sclerotiorumdevelopment and pathogenicity? (ii) In what manner do phosphotyrosinephosphatases affect S. sclerotiorumdevelopment and pathogenicity and how are they linked with ROS and other signaling pathways? And (iii) What is the nature of activity of newly identified compounds that affect S. sclerotiori,111 growth? What are the fungal targets and do they interfere with ROS signaling? We have met a significant portion of the specific goals set in our research project. Much of our work has been published. Briefly. we can summarize that: (a) Silencing of SsNox1(NADPHoxidase) expression indicated a central role for this enzyme in both virulence and pathogenic development, while inactivation of the SsNox2 gene resulted in limited sclerotial development, but the organism remained fully pathogenic. (b) A catalase gene (Scatl), whose expression was highly induced during host infection is involved in hyphal growth, branching, sclerotia formation and infection. (c) Protein tyrosine phosphatase l (ptpl) is required for sclerotial development and is involved in fungal infection. (d) Deletion of a superoxidedismutase gene (Sssodl) significantly reduced in virulence on both tomato and tobacco plants yet pathogenicity was mostly restored following supplementation with oxalate. (e) We have participated in comparative genome sequence analysis of S. sclerotiorumand B. cinerea. (f) S. sclerotiorumexhibits a potential switch between biotrophic and necrotrophic lifestyles (g) During plant­ microbe interactions cell death can occur in both resistant and susceptible events. Non­ pathogenic fungal mutants S. sclerotior111n also cause a cell death but with opposing results. We investigated PCD in more detail and showed that, although PCD occurs in both circumstances they exhibit distinctly different features. The mutants trigger a restricted cell death phenotype in the host that unexpectedly exhibits markers associated with the plant hypersensitive (resistant) response. Using electron and fluorescence microscopy, chemical effectors and reverse genetics, we have established that this restricted cell death is autophagic. Inhibition of autophagy rescued the non-pathogenic mutant phenotype. These findings indicate that autophagy is a defense response in this interaction Thus the control of cell death, dictated by the plant (autophagy) סr the fungus (apoptosis), is decisive to the outcome of certain plant­ microbe interactions. In addition to the time and efforts invested towards reaching the specific goals mentioned, both Pls have initiated utilizing (as stated as an objective in our proposal) state of the art RNA-seq tools in order to harness this technology for the study of S. sclerotiorum. The Pls have met twice (in Israel and in the US), in order to discuss .נחd coordinate the research efforts. This included a working visit at the US Pls laboratory for performing RNA-seq experiments and data analysis as well as working on a joint publication (now published). The work we have performed expands our understanding of the fundamental biology (developmental and pathogenic) of S. sclerotioז111וז. Furthermore, based on our results we have now reached the conclusion that this fungus is not a bona fide necrotroph, but can also display a biotrophic lifestyle at the early phases of infection. The data obtained can eventually serve .נ basis of rational intervention with the disease cycle of this pathogen.
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Ohad, Itzhak, et Himadri Pakrasi. Role of Cytochrome B559 in Photoinhibition. United States Department of Agriculture, décembre 1995. http://dx.doi.org/10.32747/1995.7613031.bard.

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The aim of this research project was to obtain information on the role of the cytochrome b559 in the function of Photosystem-II (PSII) with special emphasis on the light induced photo inactivation of PSII and turnover of the photochemical reaction center II protein subunit RCII-D1. The major goals of this project were: 1) Isolation and sequencing of the Chlamydomonas chloroplast psbE and psbF genes encoding the cytochrome b559 a and b subunits respectively; 2) Generation of site directed mutants and testing the effect of such mutation on the function of PSII under various light conditions; 3) To obtain further information on the mechanism of the light induced degradation and replacement of the PSII core proteins. This information shall serve as a basis for the understanding of the role of the cytochrome b559 in the process of photoinhibition and recovery of photosynthetic activity as well as during low light induced turnover of the D1 protein. Unlike in other organisms in which the psbE and psbF genes encoding the a and b subunits of cytochrome b559, are part of an operon which also includes the psbL and psbJ genes, in Chlamydomonas these genes are transcribed from different regions of the chloroplast chromosome. The charge distribution of the derived amino-acid sequences of psbE and psbF gene products differs from that of the corresponding genes in other organisms as far as the rule of "positive charge in" is concerned relative to the process of the polypeptide insertion in the thylakoid membrane. However, the sum of the charges of both subunits corresponds to the above rule possibly indicating co-insertion of both subunits in the process of cytochrome b559 assembly. A plasmid designed for the introduction of site-specific mutations into the psbF gene of C. reinhardtii. was constructed. The vector consists of a DNA fragment from the chromosome of C. reinhardtii which spans the region of the psbF gene, upstream of which the spectinomycin-resistance-conferring aadA cassette was inserted. This vector was successfully used to transform wild type C. reinhardtii cells. The spectinomycin resistant strain thus obtained can grow autotrophically and does not show significant changes as compared to the wild-type strain in PSII activity. The following mutations have been introduced in the psbF gene: H23M; H23Y; W19L and W19. The replacement of H23 involved in the heme binding to M and Y was meant to permit heme binding but eventually alter some or all of the electron transport properties of the mutated cytochrome. Tryptophane W19, a strictly conserved residue, is proximal to the heme and may interact with the tetrapyrole ring. Therefore its replacement may effect the heme properties. A change to tyrosine may have a lesser affect on the potential or electron transfer rate while a replacement of W19 by leucine is meant to introduce a more prominent disturbance in these parameters. Two of the mutants, FW19L and FH23M have segregated already and are homoplasmic. The rest are still grown under selection conditions until complete segregation will be obtained. All mutants contain assembled and functional PSII exhibiting an increased sensitivity of PSII to the light. Work is still in progress for the detailed characterization of the mutants PSII properties. A tobacco mutant, S6, obtained by Maliga and coworkers harboring the F26S mutation in the b subunit was made available to us and was characterized. Measurements of PSII charge separation and recombination, polypeptide content and electron flow indicates that this mutation indeed results in light sensitivity. Presently further work is in progress in the detailed characterization of the properties of all the above mutants. Information was obtained demonstrating that photoinactivation of PSII in vivo initiates a series of progressive changes in the properties of RCII which result in an irreversible modification of the RCII-D1 protein leading to its degradation and replacement. The cleavage process of the modified RCII-D1 protein is regulated by the occupancy of the QB site of RCII by plastoquinone. Newly synthesized D1 protein is not accumulated in a stable form unless integrated in reassembled RCII. Thus the degradation of the irreversibly modified RCII-D1 protein is essential for the recovery process. The light induced degradation of the RCII-D1 protein is rapid in mutants lacking the pD1 processing protease such as in the LF-1 mutant of the unicellular alga Scenedesmus obliquus. In this case the Mn binding site of PSII is abolished, the water oxidation process is inhibited and harmful cation radicals are formed following light induced electron flow in PSII. In such mutants photo-inactivation of PSII is rapid, it is not protected by ligands binding at the QB site and the degradation of the inactivated RCII-D1 occurs rapidly also in the dark. Furthermore the degraded D1 protein can be replaced in the dark in absence of light driven redox controlled reactions. The replacement of the RCII-D1 protein involves the de novo synthesis of the precursor protein, pD1, and its processing at the C-terminus end by an unknown processing protease. In the frame of this work, a gene previously isolated and sequenced by Dr. Pakrasi's group has been identified as encoding the RCII-pD1 C-terminus processing protease in the cyanobacterium Synechocystis sp. PCC 6803. The deduced sequence of the ctpA protein shows significant similarity to the bovine, human and insect interphotoreceptor retinoid-binding proteins. Results obtained using C. reinhardtii cells exposes to low light or series of single turnover light flashes have been also obtained indicating that the process of RCII-D1 protein turnover under non-photoinactivating conditions (low light) may be related to charge recombination in RCII due to back electron flow from the semiquinone QB- to the oxidised S2,3 states of the Mn cluster involved in the water oxidation process.
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Habib, Ayman, Darcy M. Bullock, Yi-Chun Lin et Raja Manish. Road Ditch Line Mapping with Mobile LiDAR. Purdue University, 2021. http://dx.doi.org/10.5703/1288284317354.

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Maintenance of roadside ditches is important to avoid localized flooding and premature failure of pavements. Scheduling effective preventative maintenance requires mapping of the ditch profile to identify areas requiring excavation of long-term sediment accumulation. High-resolution, high-quality point clouds collected by mobile LiDAR mapping systems (MLMS) provide an opportunity for effective monitoring of roadside ditches and performing hydrological analyses. This study evaluated the applicability of mobile LiDAR for mapping roadside ditches for slope and drainage analyses. The performance of alternative MLMS units was performed. These MLMS included an unmanned ground vehicle, an unmanned aerial vehicle, a portable backpack system along with its vehicle-mounted version, a medium-grade wheel-based system, and a high-grade wheel-based system. Point cloud from all the MLMS units were in agreement in the vertical direction within the ±3 cm range for solid surfaces, such as paved roads, and ±7 cm range for surfaces with vegetation. The portable backpack system that could be carried by a surveyor or mounted on a vehicle and was the most flexible MLMS. The report concludes that due to flexibility and cost effectiveness of the portable backpack system, it is the preferred platform for mapping roadside ditches, followed by the medium-grade wheel-based system. Furthermore, a framework for ditch line characterization is proposed and tested using datasets acquired by the medium-grade wheel-based and vehicle-mounted portable systems over a state highway. An existing ground filtering approach is modified to handle variations in point density of mobile LiDAR data. Hydrological analyses, including flow direction and flow accumulation, are applied to extract the drainage network from the digital terrain model (DTM). Cross-sectional/longitudinal profiles of the ditch are automatically extracted from LiDAR data and visualized in 3D point clouds and 2D images. The slope derived from the LiDAR data was found to be very close to highway cross slope design standards of 2% on driving lanes, 4% on shoulders, as well as 6-by-1 slope for ditch lines. Potential flooded regions are identified by detecting areas with no LiDAR return and a recall score of 54% and 92% was achieved by the medium-grade wheel-based and vehicle-mounted portable systems, respectively. Furthermore, a framework for ditch line characterization is proposed and tested using datasets acquired by the medium-grade wheel-based and vehicle-mounted portable systems over a state highway. An existing ground filtering approach is modified to handle variations in point density of mobile LiDAR data. Hydrological analyses, including flow direction and flow accumulation, are applied to extract the drainage network from the digital terrain model (DTM). Cross-sectional/longitudinal profiles of the ditch are automatically extracted from LiDAR data, and visualized in 3D point clouds and 2D images. The slope derived from the LiDAR data was found to be very close to highway cross slope design standards of 2% on driving lanes, 4% on shoulder, as well as 6-by-1 slope for ditch lines. Potential flooded regions are identified by detecting areas with no LiDAR return and a recall score of 54% and 92% was achieved by the medium-grade wheel-based and vehicle-mounted portable systems, respectively.
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Aiyar, Yamini, Vincy Davis, Gokulnath Govindan et Taanya Kapoor. Rewriting the Grammar of the Education System : Delhi’s Education Reform (A Tale of Creative Resistance and Creative Disruption). Research on Improving Systems of Education (RISE), novembre 2021. http://dx.doi.org/10.35489/bsg-rise-misc_2021/01.

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The study was not designed to undertake an evaluation of the success or failure of reform. Nor was it specifically about the desirability or defects of the policy reform choices. It took these reform choices and the policy context as a given. It is important to note that the Delhi reforms had its share of criticisms (Kumar, 2016; Rampal, 2016). However, our goal was not to comment on whether these were the “right” reforms or have their appropriateness measured in terms of their technical capability. This study sought to understand the pathways through which policy formulations, designed and promoted by committed leaders (the sound and functional head of the flailing state), transmit their ideas and how these are understood, resisted, and adopted on the ground. In essence, this is a study that sought to illuminate the multifaceted challenges of introducing change and transition in low-capacity settings. Its focus was on documenting the process of implementing reforms and the dynamics of resistance, distortion, and acceptance of reform efforts on the ground. The provocative claim that this report makes is that the success and failure, and eventual institutionalisation, of reforms depend fundamentally on how the frontline of the system understands, interprets, and adapts to reform efforts. This, we shall argue, holds the key to upending the status quo of “pilot” burial grounds that characterise many education reform efforts in India. Reforms are never implemented in a vacuum. They inevitably intersect with the belief systems, cultures, values, and norms that shape the education ecosystem. The dynamics of this interaction, the frictions it creates, and reformers’ ability to negotiate these frictions are what ultimately shape outcomes. In the ultimate analysis, we argue that reforming deeply entrenched education systems (and, more broadly, public service delivery systems) is not merely a matter of political will and technical solutions (although both are critical). It is about identifying the points of reform friction in the ecosystem and experimenting with different ways of negotiating these. The narrative presented here does not have any clear answers for what needs to be done right. Instead, it seeks to make visible the intricacies and potential levers of change that tend to be ignored in the rush to “evaluate” reforms and declare success and failure. Moving beyond success to understand the dynamics of change and resistance is the primary contribution of this study.
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Guidati, Gianfranco, et Domenico Giardini. Joint synthesis “Geothermal Energy” of the NRP “Energy”. Swiss National Science Foundation (SNSF), février 2020. http://dx.doi.org/10.46446/publication_nrp70_nrp71.2020.4.en.

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Near-to-surface geothermal energy with heat pumps is state of the art and is already widespread in Switzerland. In the future energy system, medium-deep to deep geothermal energy (1 to 6 kilometres) will, in addition, play an important role. To the forefront is the supply of heat for buildings and industrial processes. This form of geothermal energy utilisation requires a highly permeable underground area that allows a fluid – usually water – to absorb the naturally existing rock heat and then transport it to the surface. Sedimentary rocks are usually permeable by nature, whereas for granites and gneisses permeability must be artificially induced by injecting water. The heat gained in this way increases in line with the drilling depth: at a depth of 1 kilometre, the underground temperature is approximately 40°C, while at a depth of 3 kilometres it is around 100°C. To drive a steam turbine for the production of electricity, temperatures of over 100°C are required. As this requires greater depths of 3 to 6 kilometres, the risk of seismicity induced by the drilling also increases. Underground zones are also suitable for storing heat and gases, such as hydrogen or methane, and for the definitive storage of CO2. For this purpose, such zones need to fulfil similar requirements to those applicable to heat generation. In addition, however, a dense top layer is required above the reservoir so that the gas cannot escape. The joint project “Hydropower and geo-energy” of the NRP “Energy” focused on the question of where suitable ground layers can be found in Switzerland that optimally meet the requirements for the various uses. A second research priority concerned measures to reduce seismicity induced by deep drilling and the resulting damage to buildings. Models and simulations were also developed which contribute to a better understanding of the underground processes involved in the development and use of geothermal resources. In summary, the research results show that there are good conditions in Switzerland for the use of medium-deep geothermal energy (1 to 3 kilometres) – both for the building stock and for industrial processes. There are also grounds for optimism concerning the seasonal storage of heat and gases. In contrast, the potential for the definitive storage of CO2 in relevant quantities is rather limited. With respect to electricity production using deep geothermal energy (> 3 kilometres), the extent to which there is potential to exploit the underground economically is still not absolutely certain. In this regard, industrially operated demonstration plants are urgently needed in order to boost acceptance among the population and investors.
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Quinn, Meghan. Geotechnical effects on fiber optic distributed acoustic sensing performance. Engineer Research and Development Center (U.S.), juillet 2021. http://dx.doi.org/10.21079/11681/41325.

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Distributed Acoustic Sensing (DAS) is a fiber optic sensing system that is used for vibration monitoring. At a minimum, DAS is composed of a fiber optic cable and an optic analyzer called an interrogator. The oil and gas industry has used DAS for over a decade to monitor infrastructure such as pipelines for leaks, and in recent years changes in DAS performance over time have been observed for DAS arrays that are buried in the ground. This dissertation investigates the effect that soil type, soil temperature, soil moisture, time in-situ, and vehicle loading have on DAS performance for fiber optic cables buried in soil. This was accomplished through a field testing program involving two newly installed DAS arrays. For the first installation, a new portion of DAS array was added to an existing DAS array installed a decade prior. The new portion of the DAS array was installed in four different soil types: native fill, sand, gravel, and an excavatable flowable fill. Soil moisture and temperature sensors were buried adjacent to the fiber optic cable to monitor seasonal environmental changes over time. Periodic impact testing was performed at set locations along the DAS array for over one year. A second, temporary DAS array was installed to test the effect of vehicle loading on DAS performance. Signal to Noise Ratio (SNR) of the DAS response was used for all the tests to evaluate the system performance. The results of the impact testing program indicated that the portions of the array in gravel performed more consistently over time. Changes in soil moisture or soil temperature did not appear to affect DAS performance. The results also indicated that time DAS performance does change somewhat over time. Performance variance increased in new portions of array in all material types through time. The SNR in portions of the DAS array in native silty sand material dropped slightly, while the SNR in portions of the array in sand fill and flowable fill material decreased significantly over time. This significant change in performance occurred while testing halted from March 2020 to August 2020 due to the Covid-19 pandemic. These significant changes in performance were observed in the new portion of test bed, while the performance of the prior installation remained consistent. It may be that, after some time in-situ, SNR in a DAS array will reach a steady state. Though it is unfortunate that testing was on pause while changes in DAS performance developed, the observed changes emphasize the potential of DAS to be used for infrastructure change-detection monitoring. In the temporary test bed, increasing vehicle loads were observed to increase DAS performance, although there was considerable variability in the measured SNR. The significant variation in DAS response is likely due to various industrial activities on-site and some disturbance to the array while on-boarding and off-boarding vehicles. The results of this experiment indicated that the presence of load on less than 10% of an array channel length may improve DAS performance. Overall, this dissertation provides guidance that can help inform the civil engineering community with respect to installation design recommendations related to DAS used for infrastructure monitoring.
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