Miracle-dz/UniFAR-FTUs huggingface dataset:
Détermination de la répartition de potentiel dans l'espace interélectrode d'une sonde à grille plongée dans un plasma maxwellien

2014 We study different possible forms of the potential in the space between the grid and the collecting electrode of a grid probe immersed in a maxwellian plasma. The spatial variation of the potential is determined by a numerical-analysis solution of the Poisson equation in one dimension. The results are those obtained in the cases of a monotonic potential and of a potential with an extremum in the interelectrode space. LE JOURNAL DE PHYSIQUE TOME 34, OCTOBRE 1973 Classification Physics Abstracts 14.20 Considérons un plasma maxwellien isotrope, sans collision, en équilibre thermodynamique, dans lequel est plongée une sonde à grille constituée de deux électrodes planes (Fig. 1) : la grille et le collecteur, portées respectivement aux potentiels Vg et Vc par rapport au potentiel de plasma. Il est alors intéressant de connaître la répartition de potentiel dans l’espace interélectrode puisqu’elle permet de déterminer les densités de courant électronique et ionique dans ce même espace ; cette détermination faite sur le collecteur entraîne la connaissance des courants collectés par la sonde en fonction des paramètres Fc et Vg. Nous verrons en effet que suivant le type de répartition de potentiel (monotone, avec maximum ou avec minimum), les densités de courant au niveau de la sonde n’ont pas les mêmes formes analytiques. Le problème est le suivant : quel est le type de répartition de potentiel qui correspond à deux valeurs Yg et Vc des potentiels de grille et de collecteur ? L’étude théorique que nous exposons permet de dresser une carte dans le plan ( Yg, V,), donnant à l’expérimentateur les domaines où il peut espérer une véritable séparation des charges avec la sonde à grille utilisée. La théorie complète est rendue difficile par l’existence d’une gaine au voisinage de la grille. L’épaisseur de cette région de transition est habituellement de l’ordre de la longueur de Debye et le potentiel y varie très rapidement depuis le potentiel de plasma FIG. 1. Représentation schématique de la sonde à grille plongée dans le plasma. jusqu’au potentiel de grille. Ces deux remarques justifient l’approximation que nous avons faite et qui consiste à remplacer le phénomène de gaine par une discontinuité de potentiel au niveau de la grille. Une deuxième approximation, justifiée par l’existence d’une direction privilégiée (celle du champ électrique, normale aux plans des électrodes, entre grille et collecteur) nous permet de considérer que le problème est unidimensionnel. La méthode de résolution utilisée consiste à obtenir une intégrale première de l’équation de Poisson, puis d’intégrer numériquement l’équation ainsi obtenue. Des travaux semblables [1], [2] ont conduit les auteurs à la détermination du potentiel entre les deux électrodes d’une diode, mais une méthode numérique Article published online by EDP Sciences and available at http://dx.doi. org/10.1051/jphys:019730034010085900
Computational determination of effects of electric fields upon

For five prototypical energetic molecules (nitrobenzene, methyl azide, methyl nitrate, nitromethane, and dimethylnitramine), we examine computationally the effects of external electric fields upon their “trigger linkage” bonds, the breaking of which is believed to play a key role in detonation initiation. The bonds are, respectively, CNO2, NN2, ONO2, CNO2, and NNO2. The calculations are at the B3PW91/6–31G** level. We find that fields along these bonds that reinforce the molecules' intrinsic polarities also lower their energies and increase the bonds' stretching vibration frequencies. This suggests a strengthening of the bonds. Fields in the opposite direction do the reverse. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Modification of the Electrode Surface by Ag Nanoparticles Decorated Nano Diamond-Graphite for Voltammetric Determination of Ceftizoxime

A modified glassy carbon electrode with a film of nano diamondgraphite nano mixture decorated with Ag nanoparticles (AgNPsNDG/GCE) was constructed and used for sensitive voltammetric determination of ceftizoxime (CFX). Morphology of AgNPsNDG/GCE has been examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Experimental variables such as deposited amount of the modifier suspension, pH of the supporting electrolyte and accumulation potential and time were optimized by monitoring of CV and LSV responses of CFX. The results illustrate that AgNPsNDG/GCE exhibits an excellent electrocatalytic effect in the electro-oxidation of CFX that leads to a considerable improvement in the corresponding anodic peak current. This also allows the development of a highly sensitive voltammetric sensor for the determination of CFX in pharmaceutical and clinical samples. Under the optimum conditions, the modified electrode showed a linear response to the concentration of CFX in the range of 0.02–7 µM with detection limit of 6 nM. The prepared modified electrode has some remarkable electrochemical properties such as simple preparation, high sensitivity, excellent repeatability and reproducibility and long-term stability.
Detecting Cardiac Abnormalities From 12-lead ECG Signals Using Feature Selection, Feature Extraction, and Machine Learning Classification

This work represents an entry to the 2020 PhysioNET Computing in Cardiology Challenge for the team named “Whitaker's Lab. ” The algorithm we developed can be divided into three main components: feature extraction, dimensionality reduction, and classification. In the feature extraction stage, we process the provided 12-lead ECG signals to determine various features. We consider 12 time-domain statistical features per lead, as well as sparse coding features obtained from frequency information that is extracted from each ECG lead. After computing the features, we reduce the dimensionality of the statistical features using principal component analysis in an attempt to ease the computational requirements of the classifier. After feature extraction and dimensionality reduction, we classify each 12-lead ECG signal using a random forest classifier. The classifier is trained using a cross-validated grid search algorithm to help select hyperparameters. In an attempt to avoid overfitting, the classifier and unsupervised feature extraction algorithms are trained on disjoint subsets of the Challenge data. We were unable to rank and score in the test set, but using a holdout portion of the training set we achieved a validation score of − 0.744. This result is likely to be over-optimistic.
Second Paper: Instantaneous Heat Transfer Rates to the Cylinder Head Surface of a Small Compression-Ignition Engine:

Measurements of instantaneous heat transfer rates from the working fluid to the cylinder head of a small open-chamber, four-stroke, compression-ignition engine have been made at five points on the surface, using a new form of thin-film thermocouple. These observations demonstrate that flux magnitude and the form of flux variation during the cycle depend greatly on local conditions. Some of the observed phenomena are explained qualitatively. Finally, some results are presented of an analysis of fluxes averaged over all five locations, in terms of the bulk mean properties of the working fluid. It is shown that some compensation for the non-steady nature of the situation may be given by adding to the usual type of quasi-steady relation a term involving the time derivative of the bulk mean temperature.
Calculation of first contract and multiple contact minimum miscibility pressures

The objective of the present study is to develop computationally efficient algorithms for calculation of the minimum miscibility pressure between a reservoir oil and an injection gas. Fluid phases are described by an equation of state, and first contact miscibility pressures (FCMP) as well as multiple contact miscibility pressures (MCMP) are considered. The algorithm for calculation of FCMP is based on an initial determination of an oil/gas ratio, at which saturation occurs, at a specified pressure much lower than the anticipated FCMP. A parametric trace of equilibrium phase compositions and the oil/gas ratio in dependence of the specified pressure next enables a rapid location of the FCMP. For a ternary mixture, the MCMP is obtained as the pressure, at which the extension of the critical tie line is passing through the composition of either the reservoir oil (vaporizing drive) or the injection gas (condensing drive). A rapid procedure generalizing the calculation of extended tie lines for multi component mixtures, based on modified flash calculations, is described.
Characteristics of Residential Indoor Carbonaceous Aerosols: A Case Study in Guangzhou, Pearl River Delta Region

Nine residences located in Guangzhou were selected to characterise indoor fine particles (PM2.5), organic carbon (OC) and elemental carbon (EC) during summer time. These nine residences were classified into 5 types, urban without smoker, urban with smoker, newly remodelled urban, roadside and suburban. The average indoor PM2.5 concentration was 47.4 µg/m 3 , consisting of 12.5 µg/m 3 of OC and 4.4 µg/m 3 of EC. OC and EC accounted for 24.6 % and 9.9 %, respectively, of the indoor PM2.5 mass. Higher PM2.5, OC and EC concentrations were observed in the urban residences with smokers and the roadside residence, suggesting the importance of indoor sources and outdoor penetration. The highest PM2.5 and OC concentrations were observed in one of the urban residences with a smoker due to the contribution of indoor sources and the poor condition of ventilation in the kitchen. The highest EC was observed in the roadside residence, indicating the penetration of outdoor traffic emissions. Urban residences without smokers and recently remodelled residences had similar PM2.5, OC and EC concentrations. The suburban residence had the lowest PM2.5 and OC concentrations, while the EC concentration was lower than roadside residence but similar to other urban residences. Eight carbonaceous fractions by thermal/optical reflectance (TOR) method, namely OC1, OC2, OC3, OC4, OP, EC1, EC2 and EC3, were also studied. OC2, OC3 and EC1 were the most abundant fractions. EC1 was found to be the carbonaceous fraction which was mainly from outdoor vehicular emissions. OC2 and OC3 were likely to be contributed by smoking and cooking emissions in indoor microenvironments.
Étude théorique de la structure et de la stabilité des alliages GeMn dans le cadre de la spintronique. Un prototype de semiconducteur magnétique confronté aux résultats expérimentaux.

La spintronique a deja permis plusieurs avancees majeures mais le probleme de l'injection de spin s'oppose encore a son utilisation generalisee en microelectronique. Le concept de semi-conducteur magnetique dilue (DMS) a ete envisage comme solution, mais s'avere difficile a appliquer aux semi-conducteurs de type IV, dans lesquels les atomes magnetiques sont tres peu solubles et forment des precipites. Nous nous sommes interesse dans ce travail au systeme germanium manganese, et a la structure de certains precipites particuliers, qui semblent coherents avec la matrice de Ge, et dont les caracteristiques magnetiques, chimiques et structurales ne correspondent a aucun compose connu. Nous avons utilise dans ce travail des outils simulation de type ab initio par l'approche DFT avec utilisation de pseudopotentiels PAW. Nous generons dans un premier temps des pseudopotentiels necessaires pour le Ge et le Mn. Puis nous montrons grâce a une etude thermodynamique que les methodes premier principe permettent de reproduire le diagramme de phase (x,T=0) du systeme Ge(x)Mn(1-x). Nous etudions ensuite les defauts ponctuels de Mn dans la matrice de Ge et leur possibles agglomerations, et montrons qu'une "condensation" de defauts sur le reseau diamant ne peut pas expliquer les observations experimentales. Enfin, nous montrons que certains composes ordonnes derives de systemes proches sont metastables dans GeMn, et cette fois compatibles avec les mesures. Grâce a une etude complete des interfaces avec le Ge diamant, nous parvenons a expliquer la stabilite de nanocolonnes riches en Mn (33%) dans une matrice de Ge pur. Nous comparons par ailleurs les proprietes simulees de nos composes a l'experience : temperature de Curie, spectre XAS, mais aussi diffraction de rayon X et microscopie electronique a transmission (TEM).
Effect of sewage sludge addition on porosity of lightweight expanded clay aggregate (leca) and level of heavy metals leaching from ceramic matrix

The results of using municipal sewage sludge as a component of porous ceramic sinters are described. Due to high porosity the ceramic sinters can be widely applied and we have focussed on ecological aspect of this application. The results of the gaseous pollutant emission measurements carried out during industrial test are presented. Metal leaching from the end product was also tested. It was found that metals were fixed within the sinter structure. The ash matter from sludge was embodied into the solid phase.
Multistage Nanovehicle Delivery System Based on Stepwise Size Reduction and Charge Reversal for Programmed Nuclear Targeting of Systemically Administered Anticancer Drugs

The nucleus is the final target of many first‐line chemotherapeutics, but the need to overcome multiple physiological barriers imposes conflicting requirements for size and charge on systemically administered drug delivery systems. Here, an N‐(2‐hydroxypropyl) methacrylamide (HPMA) polymer‐based nanovehicle (PNV) that self‐assembles from anionic HPMA copolymers with charge‐reversal ability and cationic HPMA copolymers with intracellularly detachable subgroups (IDS) is described. The IDS, bearing an anticancer drug and nuclear‐homing cell‐penetrating peptide (R8NLS ligand), is grafted onto the HPMA copolymer via hydrazone linkage. The large, neutrally charged, self‐assembled PNV (≈55 nm) shows good blood persistence and preferential tumor accumulation. After tumoral arrival, the extracellular milieu actuates the disassembly of PNV to linear conjugates (≈10 nm/39 kDa). This first‐stage size reduction exposes R8NLS and allows for deeper tissue penetration and greater cellular internalization. After endocytosis, a second‐stage size reduction occurs when the more acidic endolysosomal pH cleaved the ≈2.4 kDa IDS off the HPMA copolymer backbone and guaranteed the successful nuclear entry via nuclear localization signal assistance. Based on the stepwise size reduction and on‐demand R8NLS exposure, the PNV inhibits growth of HeLa tumors in nude mice by 75%. This work gives important insights into the design of systemic nuclear‐targeted delivery via a multistage size/charge changing way.
Feasibility study of a hot carrier photovoltaic device

A hot carrier solar cell is characterized by a carrier population in thermal non equilibrium with the lattice, that translates into carriers having a temperature higher than the material temperature. It then becomes possible to collect not only the carrier potential energy but also their kinetic energy, and thus to extract an additional power that is not used in conventional solar cells. This enables to reach a potential efficiency close to the thermodynamical limit. The extraction of carriers is made through energy selective membranes in order to reduce the heat loss. In this thesis, the impact of contact selectivity on the cell behaviour is investigated by simulating its efficiency. It appears that this parameter is not as crucial as what was said in the literature, and that a high efficiency is indeed possible with semi-selective contacts allowing carrier extraction above an energy threshold. Such contacts would not only be much easier to fabricate in practice, but are also more compatible with the high current densities that are expected in such devices. An experimental method is also proposed to determine the non equilibrium carrier cooling rate. Carriers are photogenerated by a continuous wave laser and their temperature in steady state conditions is probed by photoluminescence as a function of the excitation power density. An empirical model is obtained that relates the power dissipation due to carrier thermalization to the electron temperature. Such model can then be used in a hot carrier solar cell model to take heat losses into account. Finally, the efficiency of a realistic cell having non ideal absorption, a cooling rate measured on real materials and semi-selective contacts is simulated. It turns out that a substantial efficiency enhancement is possible compared to single junction cells with the same band gap, but that the cooling rate measured on samples is nevertheless too high to exceed today's efficiency records. Ideas are proposed to improve the performance of the structure under investigation.
Loss of Hda activity stimulates replication initiation from I‐box, but not R4 mutant origins in Escherichia coli

Initiation of chromosome replication in Escherichia coli is limited by the initiator protein DnaA associated with ATP. Within the replication origin, binding sites for DnaA associated with ATP or ADP (R boxes) and the DnaAATP specific sites (I‐boxes, τ‐boxes and 6‐mer sites) are found. We analysed chromosome replication of cells carrying mutations in conserved regions of oriC. Cells carrying mutations in DnaA‐boxes I2, I3, R2, R3 and R5 as well as FIS and IHF binding sites resembled wild‐type cells with respect to origin concentration. Initiation of replication in these mutants occurred in synchrony or with slight asynchrony only. Furthermore, lack of Hda stimulated initiation in all these mutants. The DnaAATP containing complex that leads to initiation can therefore be formed in the absence of several of the origin DnaA binding sites including both DnaAATP specific I‐boxes. However, competition between I‐box mutant and wild‐type origins, revealed a positive role of I‐boxes on initiation. On the other hand, mutations affecting DnaA‐box R4 were found to be compromised for initiation and could not be augmented by an increase in cellular DnaAATP/DnaAADP ratio. Compared with the sites tested here, R4 therefore seems to contribute to initiation most critically.
Design and implementation of a direct-connected 11 kV power conditioner

Implementations of direct connected high-voltage AC shunt power conditioners have focused on fundamental frequency power control, while other control objectives such as harmonic compensation have not been exercised. This paper demonstrates the multi-functional capability of a prototype direct-connected, high-voltage (11 kV) power conditioner. The prototype is based on a 3-level inverter topology and uses a series connection of eight IGBTs for each switching element in the 3-phase inverter. Laboratory testing confirms that the unit can perform all of the proposed functions, namely harmonic compensation, ripple control signal injection, and VAr control.
Light-scattering and aerodynamic size measurements for homogeneous and inhomogeneous microspheres

Utilisation de la combinaison d'une balance electrodynamique et d'une chambre a diffusion de lumiere pour mettre en suspension de petites particules dans un faisceau laser et pour obtenir des donnees de diffusion de lumiere pour des particules de silicates et des microspheres recouvertes d'un revetement
The proteasome-interacting Ecm29 protein disassembles the 26S proteasome in response to oxidative stress

Oxidative stress has been implicated in multiple human neurological and other disorders. Proteasomes are multi-subunit proteases critical for the removal of oxidatively damaged proteins. To understand stress-associated human pathologies, it is important to uncover the molecular events underlying the regulation of proteasomes upon oxidative stress. To this end, we investigated H2O2 stress–induced molecular changes of the human 26S proteasome and determined that stress-induced 26S proteasome disassembly is conserved from yeast to human. Moreover, we developed and employed a new proteomic approach, XAP (in vivo cross-linking–assisted affinity purification), coupled with stable isotope labeling with amino acids in cell culture (SILAC)–based quantitative MS, to capture and quantify several weakly bound proteasome-interacting proteins and examine their roles in stress-mediated proteasomal remodeling. Our results indicate that the adapter protein Ecm29 is the main proteasome-interacting protein responsible for stress-triggered remodeling of the 26S proteasome in human cells. Importantly, using a disuccinimidyl sulfoxide–based cross-linking MS platform, we mapped the interactions of Ecm29 within itself and with proteasome subunits and determined the architecture of the Ecm29–proteasome complex with integrative structure modeling. These results enabled us to propose a structural model in which Ecm29 intrudes on the interaction between the 20S core particle and the 19S regulatory particle in the 26S proteasome, disrupting the proteasome structure in response to oxidative stress.
Distributed Energy Sharing Service Model Based on the Aggregation of Idle Equipment

In the area of distributed energy, the equipment manufacturing technology and operation model have been relatively mature, however, the lack of business model leads to low utilization rate. Therefore, a distributed energy sharing service model was proposed in this study based on the aggregation of idle equipment, which can not only meet the energy demand of users in the demand side, but also increase the utilization rate of distributed energy equipment. The service structure based on multi-agent technology was established first. Then the service process including five service stages was designed to standardize works of each participant. The energy pricing model of service provider and the cost settlement mechanism was investigated and illustrated. A case study was brought at last, verifying the rationality and feasibility of the service model established.
Synthesis and characterization of diethyl-dithiocarbamic acid 2-[4-(2-diethylthiocarbamoylsulfanyl-2-phenyl-acetyl)-2,5-dioxo-piperazin-1-yl]-2-oxo-1-phenyl-ethyl ester as new reversible addition-fragmentation chain transfer agent for polymerization of ethyl methacrylate

Abstract Diethyl-dithiocarbamic acid 2-[4-(2-diethylthiocarbamoylsulfanyl-2-phenyl-acetyl)-2,5-dioxo-piperazin-1-yl]-2-oxo-1-phenyl-ethyl ester as a novel di-functional reversible addition–fragmentation chain transfer (RAFT) agent was synthesized based on 2,5-diketopiperazine. The RAFT agent was designed based on the propagating core (R group) approach and characterized by 1H NMR, 13C NMR, FT-IR, elemental analysis, and melting point technique. Then, ethyl methacrylate was synthesized via free radical and RAFT polymerizations. To investigate the effect of the RAFT agent on the kinetic of polymerization, molecular weight, and polydispersity index (PDI) of polymers and also monomer conversion were monitored. Also, synthesized polymers were characterized by 1H NMR, 13C NMR, FT-IR, and TGA. Characterization analyses of synthesized RAFT agent were consistent with the structure. NMR and FTIR analyses confirmed end group incorporation of RAFT agent into polymer structure. According to results, poly(ethyl methacrylate) with low PDI (1.14) was obtained. Kinetic study indicated well-controlled polymerization of ethyl methacrylate by synthesized RAFT agent. TGA results showed that RAFT agent could reduce termination reactions and so reduce head-to-head bonds and chain-end unsaturation by keeping the concentration of radicals low enough.