Final Channel Research Articles

Nanochannel fabrication based on double patterning with hydrogen silsesquioxane

A double patterning process is presented to pattern sub-35 nm wide channels in hydrogen silsesquioxane with near 100% pattern densities. Using aligned electron beam lithography, each side of the nanochannel structure is patterned as a separate layer. A 50 000 μC/cm2 high-dose anneal is applied to the first layer after exposure and develop to densify the structure and improve resistance to subsequent chemical exposure. Channels with widths below ∼60 nm are shown to exhibit footing with standard tetramethyl ammonium hydroxide developers. This problem is resolved by adding surfactant during the development of the final channel structure. The resulting process produced channels <35 nm wide with smooth sidewalls and a height of 45 nm.

What Accounts for the Union Member Advantage in Voter Turnout? Evidence from the European Union, 2002-2008

Across countries, union membership and voter turnout are highly correlated. In unadjusted terms, union members maintain a roughly 0.10 to 0.12 point gap in voting propensity over non-members. We motivate empirically and propose a model—with three causal channels—that explains this correlation and then empirically tests for the contribution of each channel to the overall union voting gap. The first channel by which union members are more likely to vote is through the so-called "monopoly-face" of unionism (i.e., unionization increases wages for members and higher incomes are a significant positive determinant of voting). The second is the so-called "social custom" model of unionism, which argues that union co-worker peer pressure creates incentives to vote amongst members for the purpose of having cast a ballot or being seen at the voting poll. The third and final channel is based on the "voice-face" of unionism whereby employees who are (or have been) exposed to the formalities of collective bargaining and union representation at the workplace are also more likely to increase their attachment to structures of democratic governance in society as well. We test to see how much of the raw "union voting premium" is accounted for by these three competing channels, using contemporary data from 29 European countries. We find that all three channels are at work, with voice the dominant effect (half of the overall gap attributed to this channel) and the other two (monopoly and social custom), each accounting for approximately one-fourth of the overall union voting gap.

Breakup and finite-range effects on theB8(d,n)9Creaction

The astrophysical factor of $^{8}\mathrm{B}{(p,\ensuremath{\gamma})}^{9}\mathrm{C}$ at zero energy, ${S}_{18}(0)$, is determined by a three-body coupled-channels analysis of the transfer reaction $^{8}\mathrm{B}{(d,n)}^{9}\mathrm{C}$ at 14.4 MeV/nucleon. Effects of the breakup channels of $d$ and $^{9}\mathrm{C}$ are investigated with the continuum-discretized coupled-channels method. It is found that, in the initial and final channels, respectively, the transfer process through the breakup states of $d$ and $^{9}\mathrm{C}$, its interference with that through their ground states in particular, gives a large increase in the transfer cross section. The finite-range effects with respect to the proton-neutron relative coordinate are found to be about 20%. As a result of the present analysis, ${S}_{18}(0)=22\ifmmode\pm\else\textpm\fi{}6\phantom{\rule{0.28em}{0ex}}\mathrm{eV}\phantom{\rule{0.16em}{0ex}}\mathrm{b}$ is obtained, which is smaller than the result of the previous distorted-wave Born approximation analysis by about 51%.

Space-Time Description of Cross Sections and Durations of Neutron-Nucleus Scattering near 1 - 2 Resonances in the C- and L-Systems

The appearance of time advance (due to distortion by the non-resonant background) instead of the expected time delay in the region of a compound-nucleus resonance in the center-of-mass (C-) system is known. Here at the same conditions we study cross sections and durations of the neutron-nucleus scattering in the laboratory (L-) system. Here there are a review of papers where it is shown that such time advance is a virtual paradox and in the L-system the time-advance phenomenon does not occur and only the trivial time delay is observed. At the same time the transformations from C-system into the L-system appear to be different from the standard kinematical transformations because in the C-system the motion of a compound nucleus is absent but it is present in the L-system. Here we analyze the initial wave-packet motion (after the collision origin) and the cross section in the laboratory (L-) system. Also here (as physical revelations of profound general methodic and in very good consistent accordance with the experiment) several results of the calculated cross sections for the neutron-nucleus in comparison with the experimental data in the L-system at the range of one or two overlapped compound resonances are presented. It is shown in the space-time approach that the standard cinematic transformations of cross sections from the C-system to the L-system are not valid because it is necessary to consider the center-of-mass motion in the L-system. Finally on a correct self-consistent base of the space-time description of the nuclear processes in the laboratory system with 3 particles in the final channel, the validity of the former approach is shown, which is obtained for the space-time description of the nuclear processes with 2-particle channels earlier.

Dynamic Characteristics of Excited Atomic Systems

The dynamics of excited atom interactions with other atoms, which often lead to associative ionization, is largely governed by stochastic diffusion of the valence electron through Rydberg states prior to the ionization. Such processes are associated with random changes of the energy state of the highly excited electron, and they are likely to influence the nuclear dynamics, especially at subthermal collision energies. Possibilities of manipulation of the chaotic dynamics of Rydberg states require a detailed exploration. For an electron in a given Rydberg state moving in a microwave field, which can be generated via interaction with another atom or molecule, there exists critical field strength, above which motion of the electron in the energy space is chaotic. Recently a way to block the dynamic chaos regime was shown, if a given Rydberg state is located somewhat above the middle between the two other states with the orbital quantum number differing by one, whereby level shifts can be controlled by employing Stark/Zeeman shifts in external DC electric/magnetic fields. The stochastic effects in collisions involving Rydberg particles, in which the initial and final reaction channels are connected via intermediate highly excited collision complexes with multiple crossings of energy levels, can be treated using the dynamic chaos approach (Chirikov criterion, Standard and Keppler mapping of time evolution of the Rydberg electron, solution of the Fokker-Plank- and Langevin-type of equations, etc.). Such approach to obtaining dynamics characteristics is a natural choice, since the treatment of Rydberg electron dynamics as a kind of diffusion process allowing one to bypass the multi-level-crossing problem, which can hardly be solved by conventional quantum chemistry methods.

Transverse heat transfer coefficient in the dual channel ITER TF CICCs Part II. Analysis of transient temperature responses observed during a heat slug propagation experiment

A heat slug propagation experiment in the final design dual channel ITER TF CICC was performed in the SULTAN test facility at EPFL-CRPP in Villigen PSI. We analyzed the data resulting from this experiment to determine the equivalent transverse heat transfer coefficient hBC between the bundle and the central channel of this cable. In the data analysis we used methods based on the analytical solutions of a problem of transient heat transfer in a dual-channel cable, similar to Renard et al. (2006) and Bottura et al. (2006). The observed experimental and other limits related to these methods are identified and possible modifications proposed. One result from our analysis is that the hBC values obtained with different methods differ by up to a factor of 2. We have also observed that the uncertainties of hBC in both methods considered are much larger than those reported earlier.

Occupations, fields of study and returns to education

AbstractThis paper considers several possible channels behind the well‐documented effect of education on earnings. The first channel is that education makes workers more productive on a given task, as in a conventional human capital framework. The second channel is based on the idea that education helps workers get assigned to higher‐paying occupations where output is more sensitive to skill. A third and final channel is that workers are more productive and earn more when they are matched to a job related to their field of study. Using data from the 2005 National Graduate Survey and the 2006 Canadian Census, I find that channels two and three account for close to half of the conventionally measured return to education. The results indicate that the return to education varies greatly depending on occupation, field of study and the match between these two factors.

Trafficking of ThermoTRP Channels.

ThermoTRP channels (thermoTRPs) define a subfamily of the transient receptor potential (TRP) channels that are activated by changes in the environmental temperature, from noxious cold to injurious heat. Acting as integrators of several stimuli and signalling pathways, dysfunction of these channels contributes to several pathological states. The surface expression of thermoTRPs is controlled by both, the constitutive and regulated vesicular trafficking. Modulation of receptor surface density during pathological processes is nowadays considered as an interesting therapeutic approach for management of diseases, such as chronic pain, in which an increased trafficking is associated with the pathological state. This review will focus on the recent advances trafficking of the thermoTRP channels, TRPV1, TRPV2, TRPV4, TRPM3, TRPM8 and TRPA1, into/from the plasma membrane. Particularly, regulated membrane insertion of thermoTRPs channels contributes to a fine tuning of final channel activity, and indeed, it has resulted in the development of novel therapeutic approaches with successful clinical results such as disruption of SNARE-dependent exocytosis by botulinum toxin or botulinomimetic peptides.

1Do and 3Do doubly excited ridge states of H−: total and partial decay widths

Partial and total autodetachment widths, with interchannel coupling, for the 1Do and 3Do ridge resonances of H−, near the n = 3, 4, 5, 6 and 7 hydrogenic thresholds, have been computed. The Complex Eigenvalue Schrodinger Equations are solved variationally using complex symmetric non-Hermitian matrix equations. The 3Do shape resonance, above the n = 3 hydrogenic threshold, is included in the calculations. An approximate distribution of the vector-coupling configuration mixing coefficients, near the two electron ejection threshold, is obtained. Trends regarding the decay dynamics, the final channel distribution, and the excitation of electrons with large orbital angular momentum, near threshold, are analyzed.

On Mathematical Foundations of Quantum Collisions and Nuclear Reactions and Outcome of Certain Physical Phenomena from Them

I. Analytical structure of the non-relativistic unitary and non-unitary S-matrix is reviewed for the cases of any interactions with any motion equations inside a sphere of radius a, enclosed by centrifugal and rapidly decreasing (exponentially or by the Yukawian law or by the more rapidly decreasing) potentials. Some kinds of the symmetry conditions are imposed. The Schroedinger equation for the particle motion in the external region where r > a and the completeness of the correspondent wave functions are assumed. The connection of the obtained results with the causality is examined. Partially some analytical properties for the multi-channel S-matrix are reviewed and the sum rules for mean compound-nucleus time delays and the density of compound-nucleus levels. Sometimes (as physical manifestations of the profound general methodic and in very good consistent accordance with the experiment) observable physical effects, such as parity violation enhancement and time resonances or explosions, are appeared. Finally a scientific program of future search is presented as a clear continuation and extension of the obtained results. II. It is already known the appearance of time advance (due to distortion by the non-resonant background) instead of the expected time delay in the region of a compound-nucleus resonance in the center-of-mass (C-) system. Here at the same conditions we study cross sections and durations of the neutron-nucleus scattering in the laboratory (L-) system. Here it is shown that such time advance is a virtual paradox but in the L-system the time-advance phenomenon does not occur and only the trivial time delay is observed. At the same time the transformations from C-system into the L-system appeared to be different from the standard kinematical transformations because in the C-system the motion of a compound nucleus is absent but it is present in the L-system. We analyze the initial wave-packet motion (after the collision origin) and the cross section in the laboratory (L-) system. Also here (as physical revelations of profound general methodic and in very good consistent accordance with the experiment) several results of the calculated cross sections for the neutron-nucleus in comparison with the experimental data in the L-system at the range of one or two overlapped compound resonances are presented. It is shown in the space-time approach that the standard kinematical transformations of cross sections from the C-system to the L-system are not valid because it is necessary to consider the center-of-mass motion in the L-system. Finally on a correct self-consistent base of the space-time description of the nuclear processes in the laboratory system with 3 particles in the final channel, it is shown the validity of the former approach, obtained for the space-time description of the nuclear processes with 2-particle channels earlier.

Optimal processing of reversible quantum channels

We consider the general problem of the optimal transformation of N uses of (possibly different) unitary channels to a single use of another unitary channel in any finite dimension. We show how the optimal transformation can be fully parallelized, consisting in a preprocessing channel followed by a parallel action of all the N unitaries and a final postprocessing channel. Our techniques allow to achieve an exponential reduction in the number of the free parameters of the optimization problem making it amenable to an efficient numerical treatment. Finally, we apply our general results to find the analytical solution for special cases of interest like the cloning of qubit phase gates.

An Improved Channel Estimation Method based on Jointly Preprocessing of Time-frequency Domain in TD-LTE System

As we know, LTE is the transition between the 3G and 4G and is also the global standard of 3.9G, which has improved and enhanced the air interface technology of 3G. LTE is characterized into two cases: LTE-FDD and LTE-TDD. Since LTE-TDD is researched dominantly in China, all the studies in this paper are discussed under the TD-LTE system. However, in the TDD system, the reciprocity is usually assumed since the uplink and the downlink work at the same frequency, that is to say, the estimated channel in uplink can be used to guide some downlink transmission, such as power allocation and so on. In order to estimate the uplink channel precisely, an appropriate estimation scheme with good performance is needed. In this paper, we have studied various channel estimation algorithms based on the characteristic pilot structure in uplink. And then an improved channel estimation method based on the jointly preprocessing in time-frequency domain is proposed. This method is mainly used in the following cases: the uplink channel is not estimated accurately via the successive pilot due to the interference and noise; the data processing will introduce delay and the user moves quickly, which will cause the estimated channel is not the real downlink channel. We further process the estimated channel both in time domain and in frequency domain. The final channel is used to design the beam forming vector, thus the performance of the system will be improved. Simulation results show that, the proposed method has improved the system performance in terms of bit error rate.

IEEE 802.11 기반 시스템에서 채널추정에 관한 연구

Abstract Wireless LAN system is evolving toward high-speed data transmission and more accurate channel estimation is necessarily required to improve communication performance. The PLCP preamble field in IEEE 802.11 based wireless MODEM consists of ten short symbols and two long symbols and is used for synchronization and channel estimation. The existing least square (LS) channel estimation is based on only two long training symbols. After estimating channel response separately by using each long training symbol, the final channel estimation is obtained by the average of each estimation. In this paper, a new channel estimation algorithm is presented to improve the performance of the existing LS channel estimation algorithm. From the fact that the short training symbol consists of 12 non-zero subcarriers, it gives us a clue of being able to additionally estimate at least one fourth of channel coefficients. The new LS algorithm performs channel estimation based on both two long training symbols and a short training symbol. The proposed LS algorithm shows a little bit performance improvement over the existing LS estimation and it will be able to be applied to the IEEE 802.11p WAVE system.

Measure of the spatial size for the monopole excitation in proton scattering

We formulate a scattering radius, which will be demonstrated to be a good measure of the spatial size of a general exclusive reaction. The scattering radius is presented in a framework of the partial-wave expansion method in a general two-body scattering problem. A microscopic coupled-channel calculation is performed for proton scattering by $^{12}\mathrm{C}$ in the range of the proton's incident energy, ${E}_{p}=29.95--200$ MeV, and the scattering radii are evaluated for elastic scattering and inelastic scattering, going to the Hoyle 0${}_{2}^{+}$ state with a well-developed 3$\ensuremath{\alpha}$ structure. A prominent enhancement of the scattering radius is clearly confirmed in the 3$\ensuremath{\alpha}$ final channel in comparison to the elastic channel. The scattering radius is also calculated for excitation to the giant monopole resonance (GMR) in a microscopic coupled-channel framework. The scattering radius for the 3$\ensuremath{\alpha}$ excitation is much more enhanced than the scattering radius for the GMR excitation. The proton's incident-energy dependence of the scattering radius is also investigated, and the energy systematics strongly suggest that the scattering radius can characterize the spatial size of a reaction area, which is determined by the matter radius of a nucleus excited to a final state.

Valley formation by groundwater seepage, pressurized groundwater outbursts and crater-lake overflow in flume experiments with implications for Mars

Remains of fluvial valleys on Mars reveal the former presence of water on the surface. However, the source of water and the hydrological setting is not always clear, especially in types of valleys that are rare on Earth and where we have limited knowledge of the processes involved. We investigated three hydrological scenarios for valley formation on Mars: hydrostatic groundwater seepage, release of pressurized groundwater and crater-lake overflow. Using physical modeling in laboratory experiments and numerical hydrological modeling we quantitatively studied the morphological development and processes involved in channel formation that result from these different sources of water in unconsolidated sediment. Our results show that valleys emerging from seeping groundwater by headward erosion form relatively slowly as fluvial transport takes place in a channel much smaller than the valley. Pressurized groundwater release forms a characteristic source area at the channel head by fluidization processes. This head consist of a pit in case of superlithostatic pressure and may feature small radial channels and collapse features. Valleys emerging from a crater-lake overflow event develop quickly in a run-away process of rim erosion and discharge increase. The valley head at the crater outflow point has a converging fan shape, and the rapid incision of the rim leaves terraces and collapse features. Morphological elements observed in the experiments can help in identifying the formative processes on Mars, when considerations of experimental scaling and lithological characteristics of the martian surface are taken into account. These morphological features might reveal the associated hydrological settings and formative timescales of a valley. An estimate of formative timescale from sediment transport is best based on the final channel dimensions for groundwater seepage valleys and on the valley dimensions for pressurized groundwater release and crater-lake overflow valleys. Our experiments show that different sources of water form valleys of similar size in quite different timescales.

Electromagnetic proton form factors: perspectives for PANDA

The PANDA collaboration studies fundamental aspects of the strong interaction in the transition region between non-perturbative and perturbative QCD, investigating charmonium spectroscopy, hybrids and glueballs, hypernuclei, light and heavy meson production with antiproton beams. In this contribution we focus on leptonic final channels which give access to nucleon electromagnetic form factors. The expected precision on the electric and magnetic form factors of the proton in the time-like region and the radiative corrections to be applied to the data are discussed.

Enhancement of Electrical Stability in Oxide Thin-Film Transistors Using Multilayer Channels Grown by Atomic Layer Deposition

The effect of Hf addition on the electrical performance and bias stability of ZnO-based thin-film transistors (TFTs) has been investigated. All channel layers were deposited by atomic layer deposition with various Hf contents. In addition, multilayer oxide channel TFTs consisting of two or three Hf-doped ZnO (HZO) and ZnO layers were developed for the realization of adequate channel mobility and electrical stability. The subthreshold swing and bias stability were improved by the deposition of the thin-HZO layers with amorphous phase as the first and final channel layers. The use of a conductive ZnO layer enhanced the device mobility. The oxide TFTs with a multilayer channel of a-HZO/ZnO/ a-HZO exhibited relatively good stability and mobility due to the reduced interface trap density between the channel and dielectric layers, and the suppressed adsorption of negatively charged oxygen on the back channel. The origin of the stability issues and novel channel design are proposed on the basis of the electrical performance of various TFT structures.

Optimal data fusion of collaborative spectrum sensing under attack in cognitive radio networks

Cognitive radio networks allow opportunistic spectrum access and can significantly improve spectral efficiency. To achieve higher sensing accuracy, cognitive radio systems often require cooperation among secondary users. One of the most important aspects in collaborative spectrum sensing is the data fusion algorithm which combines the sensing results from secondary users to produce the final channel status hypothesis. However, plenty of factors may affect the performance of certain data fusion rule, for example, the individual sensing node's sensing accuracy, the number of involved nodes, and the like. If Spectrum Sensing Data Falsification (SSDF) attack exists, it will become more challenging to make proper data fusion. In this article, we first introduce framework, and then evaluate the data fusion rules in different scenarios through simulation examples. Finally, a Genetic Algorithm based optimal scheme is proposed to achieve better performance in all scenarios.

Iodine-131 monitoring in sewage plant outflow

Three different hospital sites (Oxford, Sutton and Guildford) have performed sampling of their local sewage plant outflow to determine levels of radioactivity resulting from iodine-131 patients undergoing radionuclide therapies. It was found that a maximum of 20% of activity discharged from the hospitals was present in the sewage plant final effluent channel. This is significantly below the level predicted by mathematical models in current use. The results further show that abatement systems to reduce public exposure are unlikely to be warranted at hospital sites.

Monte Carlo simulation of X-ray imaging and spectroscopy experiments using quadric geometry and variance reduction techniques

The simulation of X-ray imaging experiments is often performed using deterministic codes, which can be relatively fast and easy to use. However, such codes are generally not suitable for the simulation of even slightly more complex experimental conditions, involving, for instance, first-order or higher-order scattering, X-ray fluorescence emissions, or more complex geometries, particularly for experiments that combine spatial resolution with spectral information. In such cases, simulations are often performed using codes based on the Monte Carlo method. In a simple Monte Carlo approach, the interaction position of an X-ray photon and the state of the photon after an interaction are obtained simply according to the theoretical probability distributions. This approach may be quite inefficient because the final channels of interest may include only a limited region of space or photons produced by a rare interaction, e.g., fluorescent emission from elements with very low concentrations. In the field of X-ray fluorescence spectroscopy, this problem has been solved by combining the Monte Carlo method with variance reduction techniques, which can reduce the computation time by several orders of magnitude. In this work, we present a C++ code for the general simulation of X-ray imaging and spectroscopy experiments, based on the application of the Monte Carlo method in combination with variance reduction techniques, with a description of sample geometry based on quadric surfaces. We describe the benefits of the object-oriented approach in terms of code maintenance, the flexibility of the program for the simulation of different experimental conditions and the possibility of easily adding new modules. Sample applications in the fields of X-ray imaging and X-ray spectroscopy are discussed. Program summaryProgram title: XRMCCatalogue identifier: AERO_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AERO_v1_0.htmlProgram obtainable from: CPC Program Library, Queen’s University, Belfast, N. IrelandLicensing provisions: GNU General Public License version 3No. of lines in distributed program, including test data, etc.: 83617No. of bytes in distributed program, including test data, etc.: 1038160Distribution format: tar.gzProgramming language: C++.Computer: Tested on several PCs and on Mac.Operating system: Linux, Mac OS X, Windows (native and cygwin).RAM: It is dependent on the input data but usually between 1 and 10 MB.Classification: 2.5, 21.1.External routines: XrayLib (https://github.com/tschoonj/xraylib/wiki)Nature of problem:Simulation of a wide range of X-ray imaging and spectroscopy experiments using different types of sources and detectors.Solution method:XRMC is a versatile program that is useful for the simulation of a wide range of X-ray imaging and spectroscopy experiments. It enables the simulation of monochromatic and polychromatic X-ray sources, with unpolarised or partially/completely polarised radiation. Single-element detectors as well as two-dimensional pixel detectors can be used in the simulations, with several acquisition options. In the current version of the program, the sample is modelled by combining convex three-dimensional objects demarcated by quadric surfaces, such as planes, ellipsoids and cylinders. The Monte Carlo approach makes XRMC able to accurately simulate X-ray photon transport and interactions with matter up to any order of interaction. The differential cross-sections and all other quantities related to the interaction processes (photoelectric absorption, fluorescence emission, elastic and inelastic scattering) are computed using the xraylib software library, which is currently the most complete and up-to-date software library for X-ray parameters. The use of variance reduction techniques makes XRMC able to reduce the simulation time by several orders of magnitude compared to other general-purpose Monte Carlo simulation programs.Running time:It is dependent on the complexity of the simulation. For the examples distributed with the code, it ranges from less than 1 s to a few minutes.