Elementary Channels Research Articles

No-go theorem and a universal decomposition strategy for quantum channel compilation

We rigorously prove a no-go theorem that, in sharp contrast to the case of compiling unitary gates, it is impossible to compile an arbitrary channel to arbitrary precision with any given finite elementary channel set, regardless of the length of the decomposition sequence. However, for a fixed error bound $\ensuremath{\epsilon}$, we find a general and systematic strategy to compile arbitrary quantum channels. We construct a universal set with a constant number of $\ensuremath{\epsilon}$-dependent elementary channels, such that an arbitrary quantum channel can be decomposed into a sequence of these elementary channels followed by a unitary gate, with the sequence length bounded by $O(\frac{1}{\ensuremath{\epsilon}}log\frac{1}{\ensuremath{\epsilon}})$ in the worst case. We further optimize this approach by exploiting proximal policy optimization---a powerful deep reinforcement learning algorithm for the gate compilation. We numerically evaluate the performance of our algorithm concerning topological compiling of Majorana fermions, and we show that our algorithm can conveniently and effectively reduce the use of expensive elementary operations.

Development of a mathematical model to monitoring the velocity of subsidence of charge material column in the blast furnace based on the parameters of gas pressure in the furnace tract

A problem of estimating the velocity of subsidence of a column of charge materials using non-contact methods was considered. This is important because the level of furnace charge materials and the velocity of their subsidence are main indicators of melting intensity determining the furnace productivity. The design of a blast furnace and its blast path were described and existing methods and means of controlling the velocity of charge materials in the blast furnace were analyzed. A mathematical model was presented for estimating the velocity of subsidence of charge materials in a blast furnace based on the magnitude and fluctuations of gas pressure along the furnace shaft height. The model is based on the fact that the furnace gases rise up in the furnace shaft through elementary channels in the column of charge materials consisting of a combination of capacitances and resistances. Volume of capacities and values of resistance of elementary channels are constantly changing. This changes hydraulic resistance to gas movement in the blast furnace. The system of differential equations describes the dependence of the amplitude of pressure fluctuations on the amplitude of change in coefficients of resistance and frequency of pressure fluctuations on the frequency of change in coefficients of resistance. The experimental data on velocity of the column of charge materials and fluctuations in the pressure differential in the furnace were processed and their significant relationship was shown to confirm the previous theoretical study results. To assess the model adequacy, the simulation method was used. The results of the simulation model work were confirmed by experimental data. The developed mathematical model can be introduced into production. This will make it more economical and safer through better and more predictable control and improved flexibility in operation under different production conditions.

Drying by pervaporation in elementary channel networks

Abstract

Method of Object Image Reconstruction Using a Circular Antenna Array

The method for reconstructing object images in cross-sections using a circular antenna array when sounding space by an ultrasonic monochromatic wave is proposed. The image reconstruction is carried out by scanning the internal structure of the object placed inside the circle controlled by the focus of the circular antenna array. An algorithm for controlling the phase shift modules in the elementary radiator channels of the circular antenna array for changing the focus position is presented. Model results of the reconstruction of the image of the simplest point objects are presented. The problems of implementation of a circular array are discussed.

Bismarck’s Health Insurance and the Mortality Decline

Abstract We study the impact of social health insurance on mortality. Using the introduction of compulsory health insurance in the German Empire in 1884 as a natural experiment, we estimate difference-in-differences and regional fixed effects models exploiting variation in eligibility for insurance across occupations. Our findings suggest that Bismarck’s health insurance generated a significant mortality reduction. Despite the absence of antibiotics and most vaccines, we find the results to be largely driven by a decline of deaths from infectious diseases. Further evidence suggests that statutory access to well-trained doctors was an elementary channel. This finding may be explained by insurance fund physicians transmitting new knowledge on infectious disease prevention.

Elucidating the mechanism and kinetics of the water-assisted reaction of nitrous acid with hydroxyl radical.

The effect of a single water molecule on the atmospheric reaction between nitrous acid (HONO) and the hydroxyl radical (OH) has been investigated in this work. The CCSD(T)/aug-cc-pVTZ//UωB97X-D/aug-cc-pVTZ level of theory was used to obtain all stationary points on the energy surface and to determine the rate constants. Due to the two HONO configurations (cis- and trans-) existing in the atmosphere, the water-free HONO + OH reaction has two major elementary channels, both based on the HONO hydrogen abstraction by the hydroxyl radical. The products, NO2 + H2O, are formed with substantial energy gain, but separated by relatively low energy barriers. In the presence of water, the reaction becomes more complex, proceeding through twelve different channels, each starting with the formation of a binary complex between water and one reactant followed by its interaction with the third species. The products are similar to those of the water-free reaction. At 298 K, the rate constants of water-free cis-HONO + OH and trans-HONO + OH reactions are 1.34 × 10-12 and 1.00 × 10-15 cm3 molecule-1 s-1, respectively. The calculated rate constants for H2O-complexed HONO or OH increase by one to two orders of magnitude, but weighted by their relative abundances, the H2O-complexed fractions of the reactants in the atmosphere are so small that the effect of H2O on the overall reaction rate is minor.

From new geological paradigm to the problems of regional geological-geophysical survey

Analysis of the latest scientific achievements in different areas of geological and geophysical research showed that investigation of deep Earth degassing from its core up to the surface and atmosphere acquires status of the mainstream in the Earth sciences. Of great fundamental and applied significance is identification of the most energetically active and powerful sub-vertical upward degassing processes, which generate trans-geosphere and cross-formational systems and are localized in the form of a hierarchy of different-sized degassing pipes — from the base plume to the elementary near-surface channel. Existence of this system is ensured by a series of successive exothermic transformations of elementary recovered gases into oxide substances. As a result of given chemical reactions these substances consistently receive new portions of energy sufficient for the gradual upward breakthrough of the mantle and crust internal substance. Interpretation of mantle plumes as the basic degassing mega-tubes allows us to unite the main aspects of endogenous ore formation, naphtidogenesis in the lithosphere and ecological processes in the earth’s crust and atmosphere. The cross-formational systems serve as the structural-geological basis of degassing pipes. Given systems are the basic concentrates of the naphtides upward migration and accumulation in the multi-layered deposits. The relationship between diapirism and mega-plumes derivatives — degassing pipes becomes increasingly clear. The degassing energy is the main factor of diapirism. The locations of possible anomalous degassing in Ukraine were identified based on the analysis of geophysical and other signs of modern activation. An assumption is made of possible commercial production of natural hydrogen in some of these locations. Ecological risks of deep Earth degassing, in particular, catastrophic degassing through super volcanoes are considered. Possible directions of counteraction against these risks with the help of purposeful efforts of the progressive humanity are also discussed. There is a need to revise the strategy and methodology of further development of geological and geophysical researches in general and, in particular, the major applied research areas, such as complex geological survey, mapping, prospecting of mineral resources and geo-ecology.

Multi‐scale analysis of a migrating submarine channel system in a tectonically‐confined basin: The Miocene Gorgoglione Flysch Formation, southern Italy

AbstractThe Miocene Gorgoglione Flysch Formation records the stratigraphic product of protracted sediment transfer and deposition through a long‐lived submarine channel system developed in a narrow and elongate thrust‐top basin of the Southern Apennines (Italy). Channel‐fill deposits are exposed in an outcrop belt approximately 500 m thick and 15 km long, oriented oblique to the palaeoflow, which was roughly south‐eastward. These exceptional exposures of channel‐fill strata allow the stacking architectures and the evolution of the channel system to be analyzed at multiple scales, enabling the effects of syn‐sedimentary thrust tectonics and basin confinement on the depositional system development to be deciphered. Two end‐member types of elementary channel architecture have been identified: high‐aspect‐ratio, weakly‐confined channels, and low‐aspect‐ratio, incisional channels. Their systematic stacking results in a complex pattern of seismic‐scale depositional architectures that determines the stratigraphic framework of the deep‐water system. From the base of the succession, two prominent channel complex sets have been recognized, namely CS1 and CS2, consisting of amalgamated incisional channel elements and weakly‐confined channel elements. These channelized units are overlain by isolated incisional channels, erosional into mud‐prone slope deposits. The juxtaposition of different channel architectures is interpreted to have been governed by regional thrust‐tectonics, in combination with a high subsidence rate that promoted significant aggradation. In this scenario, the alternating ‘in sequence’ and ‘out of sequence’ tectonic pulses of the basin‐bounding thrusts controlled the activation of coarse‐clastic inputs in the basin and the resulting stacking architectures of channelized units. The tectonically‐driven confinement of the depositional system limited the lateral offset in channel stacking, preventing large‐scale avulsions. This study represents an excellent opportunity to analyze the stratigraphic evolution of a submarine channel system in tectonically‐active settings from an outcrop perspective. It should find wide applicability in analogous depositional systems, whose stratigraphic architecture has been influenced by tectonically‐controlled lateral confinement and associated lateral tilting.

Crystal structure features of RbFeO2 polymorphs and their correlation with ionic conductivity

Analysis of correlation between structural features and rubidium ion conductivity is performed for RbFeO2 polymorphs in a wide temperature range of 296–843 K. To explore the migration maps of Rb+ cations, we used neutron diffraction data for low- and high-temperature RbFeO2 polymorphs and natural tiling concept implemented in the TOPOS software. Five independent elementary channels for the Rb+ cation migration have been revealed whose cross- sections were found to be essentially different in the low-temperature form, indicating a high anisotropy of the cation conductivity. During the transition to the cubic high-temperature phase all five channels become equivalent with sharply increased cross-sections, which accounts for the increase of cations mobility and gives rise to the three-dimensional character of conductivity.

Bottle-necked ionic transport in Li2ZrO3: high temperature neutron diffraction and impedance spectroscopy

We present a study of the crystal structure, ionic conductivity and Li migration map in a wide temperature range for the Li2ZrO3 and Li1.8ZrO3-δ samples synthesized by the solid state reaction and soft chemistry methods, respectively. Both samples were found to be Li-deficient at room temperature with the partially vacant Li[1] sites. Thermally activated redistribution of Li+ ions between two lithium sites has been revealed by high temperature neutron diffraction. The redistribution of lithium results in rise of the ionic conductivity and drop of the activation energy observed on the AC conductivity data at the temperatures above 740K for Li2ZrO3 and 710K for Li1.8ZrO3-δ. It has been found that more deficient Li1.8ZrO3-δ sample prepared by the soft chemistry method exhibits enhanced ionic conductivity. Three-dimensional lithium migration map composed of the stripe-like migration pathways has been constructed. Most of the elementary channels composing lithium migration map were found to be probabilistic ones, which indicates bottle-necked ionic transport in both compounds.

A linearization of quantum channels

Because the quantum channels form a compact, convex set, we can express any quantum channel as a convex combination of extremal channels. We give a Euclidean representation for the channels whose inverses are also valid channels; these are a subset of the extreme points. They form a compact, connected Lie group, and we calculate its Lie algebra. Lastly, we calculate a maximal torus for the group and provide a constructive approach to decomposing any invertible channel into a product of elementary channels.

Development of methods of modeling and computer-aided design of compressors

Discusses the methods of calculation allowing to calculate the characteristics of cascades of profiles, rowsblade, the compressor as a whole. Make improvements to previously known methods of calculation. It is proposedto allocate an additional (along the surface current) elementary channels that can achieve output of rowsdiagrams parameters. Preparation thus permits the compressor, in turn, to calculate the characteristic of the developedengine steady and unsteady modes with high accuracy. The proposed method allows the selection ofgeometric parameters of blade rows, and in operation - perform account the influence on the characteristics ofchanges in the geometry of the blades (due to erosion, dirt, etc.). Allows you to analyze the effect of prepollutionand erosion of the blades to change the characteristics of the nodes, and the results of the identificationof the plant model to solve the inverse problem - to identify the actual values of pollution and erosion in specificstages and crowns. The resulting geometry of the rims may be used as an initial approximation for the boundaryconditions at the solid-state 3D modeling and gas-dynamic calculations in СAE- systems such as Ansys CFX.

Applied Model of Magnetization of a Granulated Material

Results of researches (of magnetic permeability) of elementary effective magnetic channel in porous (granulated) material are given. Such results permit to calculate a relative intensity of field between the grains.

Comprehensive Theoretical Studies on the Reaction of 1-Bromo-3,3,3-trifluoropropene with OH Free Radicals

The potential energy surfaces (PES) for the reaction of 1-bromo-3,3,3-trifluoropropene (CF3CHCBrH) with hydroxyl (OH) free radicals is probed theoretically at the CCSD/aug-cc-pVDZ//B3LYP/6-311++G(d,p) level of theory. All the possible stationary and first-order saddle points along the reaction paths were verified by the vibrational analysis. The calculations account for all the product channels. Based on the calculated CCSD/aug-cc-pVDZ potential energy surface, the possible reaction mechanism is discussed. Six distinct reaction pathways of 1-bromo-3,3,3-trifluoropropene (BTP) with OH are investigated. The geometries, reaction enthalpies and energy barriers are determined. Canonical transition-state theory with Wigner tunneling correction was used to predict the rate constants for the temperature range of 290–3,000 K without any artificial adjustment, and the computed rate constants for elementary channels can be accurately fitted with three-parameter Arrhenius expressions. OH addition reaction channel and the H atom abstraction channels related to the carbon-carbon double bond are found to be the main reaction channels for the reaction of 1-bromo-3,3,3-trifluoropropene (CF3CHCBrH) with hydroxyl (OH) free radicals while the products leading to CF3CHCH + BrOH and COHF2CHCBrH + F play a negligible role.

The natural tiling approach to cation conductivity in KAlO2 polymorphs

A detailed analysis of correlations between structural features and cation conductivity is performed for KAlO(2) polymorphs in a wide temperature range of 300-1023 K. To explore the migration maps of K(+) cations we have used neutron diffraction data for low- and high-temperature KAlO(2) polymorphs and applied for the first time a novel algorithm based on the natural tiling concept and implemented it into the program package TOPOS. Five independent elementary channels for the K(+) cation migration have been revealed whose cross-sections were found to be essentially different in the low-temperature form, indicating a high anisotropy of the cation conductivity. During the transition to the cubic high-temperature phase all five channels become equivalent with sharply increased cross-sections that account for the jump-like increase of the cation conductivity and gives rise to its three-dimensional character.

Local heat transfer coefficient near the spacer grids

Abstract The paper presents the experimental data of the local heat transfer in the fuel rod assembly with honeycomb type spacer grids. It was established experimentally that the separation of the boundary layer behind the spacer grid increases the interchannel coefficient of transverse mixing of flow, and therefore, the local heat transfer. If the distance between the spacer grids is relatively small, they influence one another through the redistribution of mass flow in elementary channels. The local heat transfer behind the spacer grid varies with a distance from it. The local heat transfer can be determined within ±3% using similar equations for any elementary cell.

Theoretic study of the reaction mechanism between (Me)3CO• radical and trans-3-hexene

The reaction mechanism between (Me)3CO• radical and trans-3-hexene in benzene was studied for the first time at the B3LYP/6–311++G(d,p)//B3LYP/6–31G(d)+ZPVE level. Two distinct elementary channels were identified as: (1) abstraction-addition; (2) addition-addition-elimination. Analysis of the potential energy surface demonstrates that for the title reaction, channels (1) and (2) have the major and minor contribution, respectively. Our calculated results can well explain the recently observed product distribution by Coseri et al. (J. Org. Chem. 2005, 70, 4629). However, we found that the addition-abstraction channel proposed by Coseri et al. is kinetically infeasible.

The effect of dipole potential of lipid bilayers on the properties of ion channels formed by cyclic lipodepsipeptide syringomycin E

The effect of membrane dipole potential ( ϕ d ) on the properties of ion channels formed in bilayer lipid membranes by syringomycin E (SRE), a toxin produced by Pseudomonas syringae , has been studied. It has been shown that ϕ d affects the conductance and lifetime of elementary SRE channels as well as their cluster organization, in particular, the number of elementary channels synchronously opened in the cluster and the life- time of these clusters. The channel-forming activity of SRE was found to be ϕ d -dependent. The analysis of experimental data has revealed that (i) the mechanisms of the observed effects involve the dipole-dipole and charge-dipole interactions responsible for the cooperative functioning of the elementary SRE channels; (ii) about 95% of membrane dipole potential is shielded in the SRE pore; and (iii) the channel-forming activity of SRE is mainly determined by the gating charge of the SRE channels. At the same time, the partition coefficient for the toxin distribution between the membrane and aqueous phase as well as the chemical component of the channel formation work are also responsible for the ϕ d -dependence of the SRE channel forming activity.

‘LOSCS’ Lateral Offset Stacked Channel Simulations: Towards geometrical modelling of turbidite elementary channels

ABSTRACTTurbidite hydrocarbon reservoirs are complex features, that need to be described in detail and represented as clearly as possible. The morphology and internal distribution of elementary distributary channels are dependent on depositional settings, leading to diverse arrangements at different scales. Reservoir modelling usually requires a description of sedimentary heterogeneity on a scale smaller than that given by seismic resolution. This is because seismic data only display the outside geometry of their lateral stack, i.e. a turbidite fairway. Complexes of Laterally Offset Stacked Turbidite Channels (LOSCs) also require a description based on the scales of individual channel bodies. The most common representation of channels in a fairway is by stochastic object modelling; i.e. populating the observed fairway with realistic forms representing individual channels, but with no established consistency between the individual channels. On the other hand, one essential characteristic of LOSCs is that it evolves by progressive migration laterally and/or downdip. Stochastic object modelling provides an inadequate representation of this progressive evolution, and consequently, a poor rendering of the heterogeneity distribution in the reservoir. The method we propose consists of defining a realistic succession of individual channels that can accurately build the fairway observed on seismic. ‘Realism’ is defined using criteria from the shape of individual channels, and based on the amount of displacement necessary between successive episodes. Depending on seismic resolution, the system can be constrained by one or several positions of individual channels (the most recent position of the channel is often filled with shale, therefore visible on seismic and usable as a control point). The final result is a deterministic succession of channels laterally stacked to build the seismically observed envelope. Even with no calibration, the resulting architecture respects the general ‘texture’ of the complex and provides a better simulation of flow pathways than that achieved by random object modelling.

Integrated three-dimensional modeling approach of stacked turbidite channels

Hydrocarbon fields consisting of turbidite deposits are commonly more complex than anticipated because of fine-scale sedimentary heterogeneities, which complicate the reservoir characteristics. This is particularly evident in turbiditic channel complexes with lateral channel migration. The creation of fine-scale models is founded on high-resolution seismic data, incorporating all available data together with concepts of the internal reservoir architecture. The model is essential for understanding the impact of these phenomena on reservoir characteristic distributions. The lateral extents and a real distribution of heterogeneity are still unknown; thus, our modeling workflow is incorporated into an uncertainty chain to identify and measure all uncertainties with a possible effect on static connectivity. Internal channel complex fill is composed of multiple individual (elementary) channel stacks formed during repeated erosion-deposition cycles. These elementary structures allow sand transport through deep-sea areas and the preservation of slumps and slides on channel borders, resulting in the formation of internal heterogeneities. The sideways and downdip movement of elementary channels in turbidite complexes show two typical channel patterns: lateral migration and vertical stacking. The spatial distribution of slide heterogeneities is therefore constrained by the different channel patterns. Distinguishing between these two patterns provides an understanding of heterogeneity distributions and the resulting differences in static connectivity. These contrasts can be explained as distinct preservation rates of mass-transport slide sediments within elementary channels and can thus be included in reservoir models to define preferential zones of heterogeneity preservation along turbidite complexes.