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The novel dual cooperative asymmetric aminocatalysis and Lewis acid catalysis has been successfully developed for promoting cascade Michael-cyclization reaction with high enantio-, regio- and chemo-selectivity. The simple and practical process affords a one-pot approach to synthetically useful cyclopentenes.
A technology of Receiver Autonomous Integrity Monitoring (RAIM) is developed to detect faults with redundant Global Position System (GPS) pseudorange measurements. Conventional RAIMs use only the residuals of the least square algorithm and can detect the single outlier with high probability, but they fail frequently to detect the multiple outliers correctly. This article develops a new cascade method to detect GPS multiple outliers. In the method, multiple outliers will be detected with several outlier searching steps. In the every step, LSM total residuals will be estimated after lowering of weight in wrong observations. The numerical results proved the effectiveness of the proposed cascade method.
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Two proposed structures of cuevaene A were synthesized and the NMR spectra of both structures are proved to be inconsistent with those of the natural product. The structure of cuevaene A is still unclear and needs to be revised.
Two BiFET LNAs are here reported, implemented in a 0.25 μm BiCMOS technology from ST Microelectronics. First of them, dedicated to WCDMA standard, depicts a 15.5 and 2.85 dB, S21 and noise figure (NF), respectively, under 2 mA current consumption. The second realization operates at 23 GHz for Mini-Link application. It provides a 14 dB gain and 7 dB at 22 GHz NF for an 8.2 mA current consumption under 2.5 V. Both circuits were designed according to a design flow, here depicted, based on input matching, NF and gain optimisation. A large part of the article also deals with high frequency layout considerations. Indeed useful techniques dedicated to integrated microstrip waveguides and RF inter-connections are proposed based on 3D electromagnetic field simulations.
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A simple method using a combination of conformal mapping and vortex panel method to simulate potential flow in cascades is presented. The cascade is first transformed to a single body using a conformal mapping, and the potential flow over this body is solved using a simple higher order vortex panel method. The advantage of this method over existing methodologies is that it enables the use of higher order panel methods, as are used to solve flow past an isolated airfoil, to solve the cascade problem without the need for any numerical integrations or iterations. The fluid loading on the blades, such as the normal force and pitching moment, may be easily calculated from the resultant velocity field. The coefficient of pressure on cascade blades calculated with this methodology shows good agreement with previous numerical and experimental results.
Collision cascades near symmetrical tilt grain boundaries in UO2 have been investigated at energy of 5 keV. Primary knock-on atom with a distance of 3.5 nm from grain boundaries has been accelerated towards and perpendicular to the interface. Evolvement of the cascade is tracked employing classical molecular dynamics. Time evolution of the number of displaced atoms, Frenkel pairs and replacement atoms created by cascade is given. Simulations suggest that misorientation angle of the grain boundary has no effect on the final number of displaced atoms and replacement atoms. Additionally, final spatial distribution of displaced atoms at the end of the simulations has been investigated.
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Content accesss denied Emergent dynamics in a model of visual cortex
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This paper proposes that the network dynamics of the mammalian visual cortex are highly structured and strongly shaped by temporally localized barrages of excitatory and inhibitory firing we call ‘multiple-firing events’ (MFEs). Our proposal is based on careful study of a network of spiking neurons built to reflect the coarse physiology of a small patch of layer 2/3 of V1. When appropriately benchmarked this network is capable of reproducing the qualitative features of a range of phenomena observed in the real visual cortex, including spontaneous background patterns, orientation-specific responses, surround suppression and gamma-band oscillations. Detailed investigation into the relevant regimes reveals causal relationships among dynamical events driven by a strong competition between the excitatory and inhibitory populations. It suggests that along with firing rates, MFE characteristics can be a powerful signature of a regime. Testable predictions based on model observations and dynamical analysis are proposed.
The development of a ring-opening metathesis/ring-closing metathesis/cross-metathesis (ROM–RCM–CM) cascade strategy to the synthesis of a diverse collection of bi- and tricyclic sultams is reported. In this study, functionalized sultam scaffolds derived from intramolecular Diels–Alder (IMDA) reactions undergo metathesis cascades to yield a collection of tricyclic sultams. Additional appendage-based diversity was achieved by utilizing a variety of CM partners.
This study describes the utilization of a novel conjugated copolymer, namely, poly[2,3-bis(thiophen-2-yl)-acrylonitrile-9,9′-dioctyl-fluorene] (FLC8) for organic solar cell application for the first time. The highest occupied molecular orbital and the lowest unoccupied molecular orbital of FLC8 are −5.68 and −3.55eV, respectively, which lie between the corresponding values of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methylester (PCBM). In addition, both electron and hole mobilities of FLC8 are in the range of 10 −4 (cm 2 /Vs), making it an excellent ambipolar polymer. Such unique properties make FLC8 a good candidate to form a ternary cascade bulk-heterojunction organic solar cell when blending with P3HT and PCBM. The power conversion efficiency (PCE) of the ternary cascade solar cell can be increased by up to 30% as compared with the reference cell without FLC8. We suspect that this enhancement of PCE is caused by the additional charge separation offered by the cascade structure and the fast charge transfer due to the ambipolarity of FLC8.
How do we code the letters of a word when we have to write it? We examined whether the orthographic representations that the writing system activates have a specific coding for letters when these are doubled in a word. French participants wrote words on a digitizer. The word pairs shared the initial letters and differed on the presence of a double letter (e.g., LISSER/LISTER). The results on latencies, letter and inter-letter interval durations revealed that L and I are slower to write when followed by a doublet (SS) than when not (ST). Doublet processing constitutes a supplementary cognitive load that delays word production. This suggests that word representations code letter identity and quantity separately. The data also revealed that the central processes that are involved in spelling representation cascade into the peripheral processes that regulate movement execution.
A sequential one-pot process is reported involving in situ, palladium catalysed, formation of a series of tributylstannyl-1,2-carbo and heterocyclic dialkylidene-5-membered rings from the corresponding 1,6-diynes and Bu 3 SnH. These substrates and other organostannanes are then combined with carbamyl chlorides and iodobenzenes containing proximate alkene and alkynyl groups in palladium catalysed cyclisation–anion capture cascades affording a diverse range of heterocycles in good yield.
In the fine chemical industry, the batch or fed-batch reactor functions as the heart of the transformation process. Due to the complexity of chemical synthesis, the control of these reactors remains a problem of temperature control commonly performed indirectly via the jacket of the reactor. This results in a cascade control scheme based on the control a secondary, more responsive process that influences the main process. This control loop is often referred to as the slave loop of the process. This paper highlights that the slave process of batch process units, i.e. the jacket of the reactor, can have more complex dynamics than the master loop has; and very often this could be the reason for the non-satisfying control performance. Since the slave process is determined by the mechanical construction of the unit, the above mentioned problem can be effectively handled by a model-based controller designed using an appropriate nonlinear tendency model. The presented analysis shows that the complex dynamics of the slave process can be decomposed into static nonlinear and dynamic linear parts. This decomposition is beneficial since it allows the effective incorporation of the resulted tendency model into nonlinear model-based control algorithms. Real-time control results show that the proposed methodology gives superior control performance over the widely applied cascade PID-PID control scheme.
An efficient technique, namely simultaneous perturbation with dynamic tunneling for training single hidden layer feedforward network, is proposed. A sigmoidal hidden neuron is added to the single hidden layer neural network after training. Then the cascaded network is trained again using simultaneous perturbation. The dynamic tunneling technique is employed to detrap the local minima in training. The proposed technique is shown to give better convergence results for the selected problems, namely neuro-controller, encoder, adder, demultiplexer, XOR and L-T character recognition problem.
Sigmund [P. Sigmund, Appl. Phys. Lett. 25 (1974) 169] analytically predicted that the ratio of cascade volume to energy distribution volume should follow a universal curve that is sigmoidal in shape. Subsequent Monte Carlo simulations by Walker and Thompson [R.S. Walker, D.A. Thompson, Radiat. Eff. 37 (1978) 113] showed that although this curve is sigmoidal in shape, the curve is different for different materials with large deviations from Sigmund’s prediction at high M 2 /M 1 . Our analysis of the Walker and Thompson approach has revealed an error in the analytical equations used. A correct analysis of volume ratios using a different set of equations is presented. Analysis of data produced by SRIM [J.F. Ziegler, J.P. Biersack, U. Littmark, in: The Stopping and Range of Ions in solids, Pergamon, New York, 1985] (Monte Carlo) simulations gives results that are in good agreement with Sigmund’s predictions.
Unobtrusive user authentication is more convenient than explicit interaction and can also increase system security because it can be performed frequently, unlike the current “once explicitly and for a long time” practice. Existing unobtrusive biometrics (e.g., face, voice, gait) do not perform sufficiently well for high-security applications, however, while reliable biometric authentication (e.g., fingerprint or iris) requires explicit user interaction. This work presents experiments with a cascaded multimodal biometric system, which first performs unobtrusive user authentication and requires explicit interaction only when the unobtrusive authentication fails. Experimental results obtained for a database of 150 users show that even with a fairly low performance of unobtrusive modalities (Equal Error Rate above 10%), the cascaded system is capable of satisfying a security requirement of a False Acceptance Rate less than 0.1% with an overall False Rejection Rate of less than 0.2%, while authenticating unobtrusively in 65% of cases.
The base of this paper is to find the pressure distribution over the compressor blades through a cascade, which is useful to measure the flow properties of the compressor in an actual axial compressor. The static pressure distribution is obtained from the static pressure holes around the central blade which equipped with the manometers. Plot the graph between the pressure distribution and the spacing between the leading edge to the static holes. And we have to predict the Mach number doing the same procedure to get the results. After that experimental result, we have to analyze the whole experimental cascade series of blade by using software. A result from the software is compared with the experimental measurements. We have to predict the Mach number and change the pitch of the blades and the blade angle do the same procedure as mentioned before and take different plots to analyze in which parameters the compressor blades are got the optimum pressure rise.
Immobilized cells of Actinoplanes teichomyceticus ATCC 31121 were used to selectively cleave the acyl group of A40926 yielding the deacylated form of the molecule. The feasibility of this particular biotransformation in a series of three perfectly mixed airlift bioreactors with immobilized cells was examined. A continuously operated airlift cascade was designed using a model for a series of reactors with immobilized biocatalyst beads obeying Michaelis–Menten kinetics. In independent experimental runs the cascade bioreactor system was operated continuously for 56 days with an overall conversion of 99%. Model estimates for reactor volumes and relative conversions were found to be in a good agreement with the experimental results.
An efficient and rapid synthetic strategy for the construction of a pharmaceutically important acridinone scaffold via cascade iodocyclization of functionally substituted 2-aminophenyl propynyl oxyenone is developed.
The quantum–classical Monte Carlo cascade calculation model for the muonic (non-hadronic) hydrogen atom has been modified for exotic pK  −  and $p\bar p$ atoms with strong interaction. The radiative and collision transitions were taken into account only because in such a case of “heavy” atoms the effects of exotic molecule formation are not essential. The radiative cascade was considered within the framework of quantum mechanics whereas the collisions of exotic atoms in excited states with hydrogen were described by methods of classical mechanics. The yields for the K-series X-rays in pK  −  and $p\bar p$ atoms have been calculated and compared with the experimental data.
Dialdehydes undergo ‘radical then aldol’ cyclization cascades upon treatment with SmI 2 , generating four contiguous stereocenters with high diastereocontrol. The scope of the process has been explored and the cascade has been extended to also include lactone reduction.
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