Avalanches of electrons in a gas

1986 ◽  
Vol 23 (4) ◽  
pp. 867-879 ◽  
Author(s):  
F. W. Steutel
Keyword(s):  
State Process ◽  
Quantity Of Interest ◽  
Extra Electron ◽  
Moving Particle

The motion of electrons through a gas of particles is modelled as a two-state process: an electron is alternatingly moving and being held captive by a non-moving particle, during exponentially distributed periods.The model contains a parameter p, the probability that collision of an electron with a gas particle does not lead to its capture but produces an extra electron.The quantity of interest is the current C(t) produced by the moving electrons, as a function of time.

Avalanches of electrons in a gas

1986 ◽  
Vol 23 (04) ◽  
pp. 867-879
Author(s):  
F. W. Steutel
Keyword(s):  
State Process ◽  
Quantity Of Interest ◽  
Extra Electron ◽  
Moving Particle

The motion of electrons through a gas of particles is modelled as a two-state process: an electron is alternatingly moving and being held captive by a non-moving particle, during exponentially distributed periods. The model contains a parameter p, the probability that collision of an electron with a gas particle does not lead to its capture but produces an extra electron. The quantity of interest is the current C(t) produced by the moving electrons, as a function of time.

Avalanches of electrons in a gas

1986 ◽  
Vol 23 (04) ◽  
pp. 867-879
Author(s):  
F. W. Steutel
Keyword(s):  
State Process ◽  
Quantity Of Interest ◽  
Extra Electron ◽  
Moving Particle

The motion of electrons through a gas of particles is modelled as a two-state process: an electron is alternatingly moving and being held captive by a non-moving particle, during exponentially distributed periods.The model contains a parameterp, the probability that collision of an electron with a gas particle does not lead to its capture but produces an extra electron.The quantity of interest is the currentC(t) produced by the moving electrons, as a function of time.

Examination of Extra Electron Diffraction Spots Observed in Deuterium-Irradiated Silicon by Using Parallel Electron Beam Illumination

1990 ◽  
Vol 48 (2) ◽  
pp. 490-491
Author(s):  
Ryuichiro Oshima ◽  
Shoichiro Honda ◽  
Tetsuo Tanabe
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silicon Single Crystal ◽  
Mixed Solution ◽  
Parallel Beam ◽  
Defect Clusters ◽  
Float Zone ◽  
Transmission Electron ◽  
Extra Electron ◽  
Diffraction Patterns

In order to examine the origin of extra diffraction spots and streaks observed in selected area diffraction patterns of deuterium irradiated silicon, systematic diffraction experiments have been carried out by using parallel beam illumination.Disc specimens 3mm in diameter and 0.5mm thick were prepared from a float zone silicon single crystal(B doped, 7kΩm), and were chemically thinned in a mixed solution of nitric acid and hydrogen fluoride to make a small hole at the center for transmission electron microscopy. The pre-thinned samples were irradiated with deuterium ions at temperatures between 300-673K at 20keV to a dose of 1022ions/m2, and induced lattice defects were examined under a JEOL 200CX electron microscope operated at 160kV.No indication of formation of amorphous was obtained in the present experiments. Figure 1 shows an example of defects induced by irradiation at 300K with a dose of 2xl021ions/m2. A large number of defect clusters are seen in the micrograph.

Microstructure of YBa2Cu3O7-x thin films deposited by dc sputtering

1989 ◽  
Vol 47 ◽  
pp. 172-173
Author(s):  
O. Eibl ◽  
G. Gieres ◽  
H. Behner
Keyword(s):  
Thin Films ◽  
Cross Sections ◽  
Intermediate Layer ◽  
Amorphous State ◽  
Critical Currents ◽  
Dc Sputtering ◽  
State Process ◽  
Diffraction Patterns ◽  
Film Substrate ◽  
Substrate Temperatures

The microstructure of high-Tc YBa2Cu3O7-X thin films deposited by DC-sputtering on SrTiO3 substrates was analysed by TEM. Films were either (i) deposited in the amorphous state at substrate temperatures < 450°C and crystallised by a heat treatment at 900°C (process 1) or (ii) deposited at around 740°C in the crystalline state (process 2). Cross sections were prepared for TEM analyses and are especially useful for studying film substrate interdiffusion (fig.1). Films deposited in process 1 were polycristalline and the grain size was approximately 200 nm. Films were porous and the size of voids was approximately 100 nm. Between the SrTiO3 substrate and the YBa2Cu3Ox film a densly grown crystalline intermediate layer approximately 150 nm thick covered the SrTiO3 substrate. EDX microanalyses showed that the layer consisted of Sr, Ba and Ti, however, did not contain Y and Cu. Crystallites of the layer were carefully tilted in the microscope and diffraction patterns were obtained in five different poles for every crystallite. These patterns were consistent with the phase (Ba1-XSrx)2TiO4. The intermediate layer was most likely formed during the annealing at 900°C. Its formation can be understood as a diffusion of Ba from the amorphously deposited film into the substrate and diffusion of Sr from the substrate into the film. Between the intermediate layer and the surface of the film the film consisted of YBa2Cu3O7-x grains. Films prepared in process 1 had Tc(R=0) close to 90 K, however, critical currents were as low as jc = 104A/cm2 at 77 K.

Das Schicksal Priszillians und seiner Anhänger 380 in Saragossa, 384 in Bordeaux und 385 in Trier

2020 ◽  
Vol 49 (1) ◽  
pp. 30-57
Author(s):  
Klaus Martin Girardet
Keyword(s):  
Death Penalty ◽  
Late Antiquity ◽  
State Process ◽  
Process Procedures

Abstract Priscillian and some of his followers were victims of synodal and state process procedures in which bishops acted as prosecutors and supporters of the death penalty imposed at Trier. The accusation was that the Priscillians were heretics (Manichaeans) and practiced maleficium, i.e. sorcery, both prohibited by law. The source situation to this already in late antiquity often as scandalous condemned case – among others by the bishops of Tours, Milan and Rome –, is very insufficient for important details. In particular, there are very few texts which can be satisfactorily evaluated for the question of conciliar majorities and minorities and possibly controversial debates. Nevertheless, with the help of the writings of Priscillian and Sulpicius Severus, it is possible at least to reconstruct with some degree of reliability the interaction between ecclesiastical and state jurisdiction, as it was largely regulated by canons and imperial laws.

Spectroscopic Studies of Asparaginyl-tRNA Synthetase from Entamoeba histolytica

2019 ◽  
Vol 26 (6) ◽  
pp. 435-448
Author(s):  
Priyanka Biswas ◽  
Dillip K. Sahu ◽  
Kalyanasis Sahu ◽  
Rajat Banerjee
Keyword(s):  
Circular Dichroism ◽  
Steady State ◽  
Entamoeba Histolytica ◽  
Protein Concentration ◽  
Trna Synthetase ◽  
Solvent Exposure ◽  
Steady State Fluorescence ◽  
State Process ◽  
Wide Range ◽  
Circular Dichroïsm

Background: Aminoacyl-tRNA synthetases play an important role in catalyzing the first step in protein synthesis by attaching the appropriate amino acid to its cognate tRNA which then transported to the growing polypeptide chain. Asparaginyl-tRNA Synthetase (AsnRS) from Brugia malayi, Leishmania major, Thermus thermophilus, Trypanosoma brucei have been shown to play an important role in survival and pathogenesis. Entamoeba histolytica (Ehis) is an anaerobic eukaryotic pathogen that infects the large intestines of humans. It is a major cause of dysentery and has the potential to cause life-threatening abscesses in the liver and other organs making it the second leading cause of parasitic death after malaria. Ehis-AsnRS has not been studied in detail, except the crystal structure determined at 3 Å resolution showing that it is primarily α-helical and dimeric. It is a homodimer, with each 52 kDa monomer consisting of 451 amino acids. It has a relatively short N-terminal as compared to its human and yeast counterparts. Objective: Our study focusses to understand certain structural characteristics of Ehis-AsnRS using biophysical tools to decipher the thermodynamics of unfolding and its binding properties. Methods: Ehis-AsnRS was cloned and expressed in E. coli BL21DE3 cells. Protein purification was performed using Ni-NTA affinity chromatography, following which the protein was used for biophysical studies. Various techniques such as steady-state fluorescence, quenching, circular dichroism, differential scanning fluorimetry, isothermal calorimetry and fluorescence lifetime studies were employed for the conformational characterization of Ehis-AsnRS. Protein concentration for far-UV and near-UV circular dichroism experiments was 8 µM and 20 µM respectively, while 4 µM protein was used for the rest of the experiments. Results: The present study revealed that Ehis-AsnRS undergoes unfolding when subjected to increasing concentration of GdnHCl and the process is reversible. With increasing temperature, it retains its structural compactness up to 45ºC before it unfolds. Steady-state fluorescence, circular dichroism and hydrophobic dye binding experiments cumulatively suggest that Ehis-AsnRS undergoes a two-state transition during unfolding. Shifting of the transition mid-point with increasing protein concentration further illustrate that dissociation and unfolding processes are coupled indicating the absence of any detectable folded monomer. Conclusion: This article indicates that GdnHCl induced denaturation of Ehis-AsnRS is a two – state process and does not involve any intermediate; unfolding occurs directly from native dimer to unfolded monomer. The solvent exposure of the tryptophan residues is biphasic, indicating selective quenching. Ehis-AsnRS also exhibits a structural as well as functional stability over a wide range of pH.

scholarly journals LNG Tank Sloshing Simulation of Multidegree Motions Based on Modified 3D MPS Method

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Chunhui Wang ◽  
Chunyu Guo ◽  
Fenglei Han
Keyword(s):  
Free Surface ◽  
Weighted Average ◽  
Kernel Functions ◽  
Computational Stability ◽  
Mps Method ◽  
Fluid Sloshing ◽  
Particle Hydrodynamics ◽  
Moving Particle ◽  
Lng Tank ◽  
Stability And Accuracy

Modified 3D Moving Particle Semi-Implicit (MPS) method is used to complete the numerical simulation of the fluid sloshing in LNG tank under multidegree excitation motion, which is compared with the results of experiments and 2D calculations obtained by other scholars to verify the reliability. The cubic spline kernel functions used in Smoothed Particle Hydrodynamics (SPH) method are adopted to reduce the deviation caused by consecutive two times weighted average calculations; the boundary conditions and the determination of free surface particles are modified to improve the computational stability and accuracy of 3D calculation. The tank is under forced multidegree excitation motion to simulate the real conditions of LNG ships, the pressures and the free surfaces at different times are given to verify the accuracy of 3D simulation, and the free surface and the splashed particles can be simulated more exactly.

scholarly journals Run-and-Tumble Motion: The Role of Reversibility

2021 ◽  
Vol 183 (3) ◽  
Author(s):  
Bart van Ginkel ◽  
Bart van Gisbergen ◽  
Frank Redig
Keyword(s):  
Free Energy ◽  
Diffusion Coefficient ◽  
Large Deviations ◽  
Energy Function ◽  
Internal State ◽  
Rate Function ◽  
Free Energy Function ◽  
Large Deviations Principle ◽  
Preferred Direction ◽  
State Process

AbstractWe study a model of active particles that perform a simple random walk and on top of that have a preferred direction determined by an internal state which is modelled by a stationary Markov process. First we calculate the limiting diffusion coefficient. Then we show that the ‘active part’ of the diffusion coefficient is in some sense maximal for reversible state processes. Further, we obtain a large deviations principle for the active particle in terms of the large deviations rate function of the empirical process corresponding to the state process. Again we show that the rate function and free energy function are (pointwise) optimal for reversible state processes. Finally, we show that in the case with two states, the Fourier–Laplace transform of the distribution, the moment generating function and the free energy function can be computed explicitly. Along the way we provide several examples.

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