Miracle-dz/UniFAR-FTUs huggingface dataset:
Temperature dependent photoresponse from colloidal PbS quantum dot sensitized inorganic/organic hybrid photodiodes

Inorganic/organic hybrid photodiodes, based on a solution-processed ternary blend containing PbS quantum dots (QDs), a fullerene derivative, and a conjugated polymer, have been reported to exhibit external quantum efficiencies in the infrared of up to 51% [T. Rauch et al., Nat. Photonics 3, 332 (2009)]. Temperature dependent experiments reveal the high sensitivity of the photoresponse on the energy level alignment between the QDs and the fullerene derivative, resulting in quenching of the photoresponse at low temperatures for 5.2 nm QDs in size. With smaller QDs the optimum operation temperature is found between room temperature and 72 °C, making these photodiodes promising for various applications.
Investigations of Secondary Contribution to Electrocaloric Effect in Relaxor PMN-PT Ceramic

In this work, primary and secondary contributions to electrocaloric effect were investigated in a relaxor PMN-PT ceramic, by combining polarization and strain hysteretic measurements. Our results indicate that, although the ceramic shows a large electromechanical response, field-induced dimensional change (secondary effect) accounts for less than 19 % of the ceramic electrocaloric response over the 30-200°C temperature range. We believe that the method for the characterization of electrocaloric materials presented herein can provide valuable insights into the development of novel and optimized materials and heterostructures by tailoring primary and secondary contributions.
Spectrophotometry of Seyfert 2 galaxies and narrow-line radio galaxies

Results are reported for a spectrophotometric survey of several Seyfert 2 galaxies, intermediate Seyferts, and narrow-line radio galaxies. The emission-line spectra of the galaxies are analyzed, emphasizing line intensities, reddening, temperatures, densities, line strength correlations, line widths, and redshift differences. The continuous spectra are examined, and possible ionization sources are considered. It is found that: (1) there are no distinguishing differences between the spectra of Seyfert 2 galaxies and narrow-line radio galaxies; (2) the emission spectra are rich in lines from a wide range of ionization levels; (3) the continuum is starlight diluted by an underlying continuous spectrum; (4) the line widths of both classes of galaxies have the same distribution; (5) there appear to be regions of high and low ionization in the Seyfert 2 and narrow-line radio galaxies; (6) photoionization seems quite likely as the energy input to the gas; and (7) all the galaxies show a UV excess in their spectra.
Solving non-linear complementarity problem by a derivative-free descent method

The non-linear complementarity problem (NCP) has many important applications in operations research, economic equilibrium, models, mathematical programming, engineering and mechanics. In this paper, we consider smooth NCP on the basis of the square Kanzowâ€“Kleinmichel function. We show under certain assumptions, any stationary point of the unconstrained minimisation problem is already a solution of smooth NCP. Also, we suggest a derivative-free descent algorithm and give conditions for its convergence. Furthermore, we present some preliminary numerical results.
Rheology of polymer‐thickened emulsions

The flow properties of emulsions of oil in non‐Newtonian polymeric media were studied using a coaxial cylinder viscometer. The emulsions were prepared using a petroleum oil and aqueous solutions of poly(ethylene oxide) resins. Three different molecular weight poly(ethylene oxide) resins were studied. The effects of polymer concentration and oil concentration on the viscous properties of emulsions were determined. The polymer solutions and their emulsions followed the well‐known Ellis model. The relative viscosities for polymer‐thickened emulsions were found to be significantly lower than the corresponding values for emulsions without polymer. These findings are explained in terms of an increase in the viscosity ratio ηc/ηd (where ηc is the viscosity of the polymer‐thickened continuous medium and ηd is the viscosity of the dispersed oil). An increase in this ratio enhances the internal circulation effect which leads to a decrease in the relative viscosity. A new equation is proposed which describes the rel.
Maximizing the Correlation of Grouped Observations

Abstract A continuous bivariate distribution is grouped by intervals on the margins so as to obtain a discrete bivariate distribution. Marginal variates are considered which are the scores (or mean values) on the intervals of the first canonical variables associated with the ungrouped distribution. A method is suggested for choosing the end points of the intervals so as to obtain the maximum possible correlation between these marginal variates. The solution is exact when only one margin is grouped and approximate when both are. Tables of interval end points (in terms of the c.d.f.) and of the resulting correlation are given for the case of a bivariate normal distribution.
Maximizing mixing and alignment of orientable particles for reaction enhancement

We present a model for the evolution of concentrations of orientable species undergoing a collisional binary reaction and examine the dependence of the concentration of the reaction product on flow parameters in Poiseuille flow. Interesting patterns of concentration are obtained depending on parameters. We use the model to investigate the reaction in a microfluidic device known as the shear superposition micromixer. Simulation results over a range of Peclet, Damkohler, and rotational Peclet numbers indicate that this micromixer is well suited to enhance the rate of reaction via the mechanism of simultaneous mixing and alignment of the orientable species. Connections to biological systems are discussed.
Modulation of intensity in defocused beams

Many synchrotron experimental techniques require a variable size x-ray photon beam on the sample or on the detector. The easiest way to achieve this, with the minimum set of optical elements, is to defocus the beam, typically by changing the bending radius of the focusing mirrors. Nevertheless, to defocus the beam from sample has the problem that the beam profile is heavily modulated by striations caused by the surface error of the focusing optics. To our knowledge, a relationship between these modulations of the beam and the surface errors that originates them has not been properly established. In this work we show that beam modulation of a defocused beam has a nonlinear dependence on the slope profile of the mirror. From the derived relationships it follows that the relative contributions to beam striations of slope error lower and higher spatial frequencies vary depending on how far away the measurement plane is from the image plane. We explore the relationship between the amplitude of the striations and the power spectral density of the slope errors.
Saturation effects in dynamic electrowetting

The same mechanism responsible for contact angle saturation of electrically stressed aqueous droplets also clamps the electromechanical force exerted on aqueous liquids in structures using dielectric-coated electrodes. Alternating current frequency strongly influences the upper limit imposed on this force. Furthermore, studies of transient, field-induced motion suggest that this mechanism is suppressed when the contact line moves rapidly along the coated electrodes.
Optimality of Gene Ranking Based on Univariate P-values for Detecting Differentially Expressed Genes

Ranking signiﬁcant genes based on the P-value in multiple testing is a simple and common practice in microarray data analysis, and its theoretical optimality is of particular interest. McLachlan et al.( Bioinformatics 2006; 22 : 1608-1615) presented a method for calculating the local FDR under normal mixture models and provided a theoretical optimality of the local FDR as a ranking statistic. In this article, we show that the optimal gene ranking based on the local FDR calculated by the McLachlan et al.’s method perfectly accords with that based on P-value under certain conditions. We argue that these conditions are generally satisﬁed for signiﬁcant genes with small P-values. We demonstrate it using several real examples.
Solar p-mode frequencies and their dependence on solar-activity - recent results from the BISON network

We present here high-accuracy determinations of the frequencies of low-l solar p-modes and their solar-cycle dependence. The data were obtained using the Birmingham network of solar spectrometers (BISON). The precision of the measurements is discussed. Our previously published results of a significant frequency shift between solar minimum and solar maximum, apparently independent of l and similar to that found by other workers for intermediate-l modes, is confirmed and extended. This suggests that at most only a small fraction of the variation is due to the solar core. Sets of frequencies at high and low solar activity, and an average corrected for solar-activity effects, are presented. There is now evidence that the solar-activity dependence of the frequencies varies across the 5 minute spectrum.
Highly optimized embedded-atom-method potentials for fourteen fcc metals

Highly optimized embedded-atom-method (EAM) potentials have been developed for 14 face-centered-cubic (fcc) elements across the periodic table. The potentials were developed by fitting the potential-energy surface (PES) of each element derived from high-precision first-principles calculations. The as-derived potential-energy surfaces were shifted and scaled to match experimental reference data. In constructing the PES, a variety of properties of the elements were considered, including lattice dynamics, mechanical properties, thermal behavior, energetics of competing crystal structures, defects, deformation paths, liquid structures, and so forth. For each element, the constructed EAM potentials were tested against the experiment data pertaining to thermal expansion, melting, and liquid dynamics via molecular dynamics computer simulation. The as-developed potentials demonstrate high fidelity and robustness. Owing to their improved accuracy and wide applicability, the potentials are suitable for high-quality atomistic computer simulation of practical applications.
Importance of the indentation depth in tapping-mode atomic force microscopy study of compliant materials

We studied the response of a cantilever tapping on polydimethylsiloxane (PDMS) samples of different crosslink density. It is shown experimentally that the tip deeply penetrates into the compliant PDMS samples. A more compliant material leads to a larger indentation such that at a given set-point ratio the indentation force is nearly constant on samples of different elastic moduli. This confirms the simulations by J. Tamayo and R. Garcia [Appl. Phys. Lett. 71, 2394 (1997)] that phase contrast acquired at constant set point does not depend on the sample’s modulus if other contrast relevant parameters remain identical. PDMS samples of different crosslink density are distinguished in terms of amplitude and phase versus distance measurements if the tip-sample interaction is made substantially large and indentation is taken into account.
Analysis of effect of cycle spinning on wavelet- and curvelet-based denoising methods on brain CT images

The purpose of this paper is to carry out the assessment of effect of cycle spinning on wavelet- and curvelet-based noise reduction methods on brain CT images. In particular, multiscale curvelet- and wavelet-based denoising methods are evaluated with and without cycle spinning. This assessment is focused not only on the noise suppression but also on fine details preservation. The experimental results show that the cycle spinning-based curvelet method outperforms not only other curvelet-based methods but also the wavelet-based methods. The quality assessment parameters taken in this paper are signal-to-noise ratio (SNR), peak-signal-to-noise ratio (PSNR), universal quality index (UQI), structural similarity index metrics (SSIM), and edge keeping index (EKI).
Late Twentieth-Century Warming and Variations in Cloud Cover

From 1950 to 1987 a strong relationship existed between the El Nino-Southern Oscillation (ENSO) and HadCRUT4 global average temperature anomaly, interrupted occasionally by volcanic erup-tions. After 1987 the relationship diverged, with temperature anomaly increasing more than ex-pected, but was re-established after 1997 at an offset of ~0.48°C higher. The period of increased warming from 1987 to 1997 loosely coincided with the divergence of the global average tempera-ture anomalies over land, which are derived from observation station recordings, and the global average anomalies in sea surface temperatures. Land-based temperatures averaged 0.04°C below sea temperatures for the period 1950 to 1987 but after 1997 averaged 0.41°C above sea tempera-tures. The increase in the global average temperature anomaly and the divergence of land and sea surface temperatures also coincided with two significant changes in global average cloud cover. Total cloud cover decreased during the period from 1987 to 1997 and, for most of the remainder of the period from 1984 to 2009, decreases in low-level cloud were accompanied by increases in middle and upper level cloud. These changes can be found in both global average cloud cover and in each of the six 30°C-latitude bands. The impact of these changes in cloud cover can account for the variations in HadCRUT4 global average temperature anomalies and the divergence between land and sea temperatures.
An RFID-Based Digital Bracelet for the Timely Assistance of Indigents

High rates of indigence characterize several countries in Latin America, such as Mexico. In the north of our country, the phenomenon of migration contributes to indigence. To get a preliminary understanding of the needs of indigents in our community, we conducted interviews with homeless and migrants. This helped us identify preliminary system requirements that led to the design of a digital bracelet to enable local agencies to monitor and provide support to the indigents who roam the city. We refined our conceptual design through an iterative process of contextual inquiry, persona development, prototyping, and user assessment. An evaluation of our design was conducted with the coordinator of the main social assistance agency of the municipality, which allowed us to confirm the system potential to be used and adopted.
GRAPH SPECTRAL TECHNIQUES IN COMPUTER SCIENCES

We give a survey of graph spectral techniques used in computer sciences. The survey consists of a description of particular topics from the theory of graph spectra independently of the areas of Computer science in which they are used. We have described the applications of some important graph eigenvalues (spectral radius, algebraic connectivity, the least eigenvalue etc.), eigenvectors (principal eigenvector, Fiedler eigenvector and other), spectral reconstruction problems, spectra of random graphs, Hoffman polynomial, integral graphs etc. However, for each described spectral technique we indicate the fields in which it is used (e.g. in modelling and searching Internet, in computer vision, pattern recognition, data mining, multiprocessor systems, statistical databases, and in several other areas). We present some novel mathematical results (related to clustering and the Hoffman polynomial) as well.
A Comprehensive Study of Pulse Profile Evolution in SGR 1806–20 and SGR 1900+14 with the Rossi X-Ray Timing Explorer Proportional Counter Array

Soft gamma repeaters undergo pulse profile changes in connection with their burst activity. Here we present a comprehensive pulse profile history of SGR 1806-20 and SGR 1900+14 in three energy bands using Rossi X-Ray Timing Explorer/Proportional Counter Array observations performed between 1996 and 2001. Using the Fourier harmonic powers of pulse profiles, we quantify the pulse shape evolution. Moreover, we determined the rms pulsed count rates (PCRs) of each profile. We show that the pulse profiles of SGR 1806-20 remain single pulsed, showing only modest changes for most of our observing span, while those of SGR 1900+14 change remarkably in all energy bands. Highly significant pulsations from SGR 1900+14 following the 1998 August 27 and 2001 April 18 bursts enabled us to study not only the decay of PCRs in different energy bands but also their correlations with each other.
Recurrent novae as a consequence of the accretion of solar material onto a 1. 38 M/sub sun/ white dwarf

We have computed three evolutionary sequences which treat the accretion of hydrogen-rich material onto 1.38 M/sub sun/ white dwarfs. In each of these sequences the accreting matter had only a solar composition of the CNO nuclei (Z = 0.015). In the first sequence we utilized an accretion rate of 1.7 x 10/sup hyphen8/ M/sub sun/ yr/sup hyphen1/ onto a white dwarf with an initial luminosity of 0.1 L/sub sun/ . It took this sequence '33 yr to reach the peak of the thermonuclear runaway which resulted in an outburst that ejected 3x10/sup hyphen8/ M/sub sun/ . of material moving at speeds up to 2900 kn s/sup hyphen1/. The light curve, the time to outburst, and the amount of mass ejected during the evolution are in excellent agreement with the observed outburst of Nova U Sco 1979. However, only 6% of the accreted envelope was ejected during the outburst. The remaining material quickly burned to helium ('2 yr) and settled back onto the white dwarf. The second study involved an accretion rate of 1.7x10/sup hyphen9/ M/sub sun/ yr/sup hyphen1/ onto a white dwarf with an initial luminosity of 10/sup hyphen2/ L/sub sun/ . It took nearly 1600 yr to reach themore » burst phase of the evolution, and by this time the dwarf had accreted '3x10/sup hyphen6/ M/sub sun/ . Peak temperature in the shell source reached 3.5x10/sup 8/ K, about 1.3x10/sup 8/ K higher than was found for model 1. This sequence ejected 3x10/sup hyphen7/ M/sub sun/, only 13% of the accreted envelope, moving at low velocities. For both of these evolutionary sequences, we find that as a result of the accretion of matter onto a massive white dwarf, the mass of the white dwarf grows toward the Chandrasekhar limit. If our study is a realistic representation of the evolution of U Sco, then this star is well on its way to becoming an SN I. « less
Measurements of tangential momentum accommodation coefficient for various gases in plane microchannel

Mass flow rate measurements in a single silicon microchannel were carried out for various gases in isothermal steady flows. The results obtained from hydrodynamic to near free molecular regime by using a powerful experimental platform allowed us to deduce interesting information, notably about the reflection/accommodation process at the wall. In the 0–0.3 Knudsen range, a continuum analytic approach was derived from the NS equations, associated with first or second order slip boundary conditions. Identifying the experimental mass flow rate curves to the theoretical ones the tangential momentum accommodation coefficient (TMAC) of various gases was extracted. Over the full Knudsen range [0–30] the experimental results were compared with theoretical values calculated from the kinetic approaches: using variable accommodation coefficient values as fitting parameter, the theoretical curves were fitted to the experimental ones. Whatever the Knudsen range and whatever the theoretical approach, the TMAC values are.
Solving singularly perturbed advection–reaction equations via non‐standard finite difference methods

We design and implement two non‐standard finite difference methods (NSFDMs) to solve singularly perturbed advection–reaction equations (SPARE). Our methods constitute a big plus to the class of those ‘rare’ fitted operator methods, which can be extended to singularly perturbed partial differential equations. Unlike the standard finite difference methods (SFDMs), the NSFDMs designed in this paper allow the time and the space step sizes to vary independently of one another and of the parameter ε in the SPARE under consideration. The NSFDMs replicate the linear stability properties of the fixed points of the continuous problem. Furthermore, these methods preserve the positivity and boundedness properties of the exact solution. Numerical simulations that confirm the theoretical results are presented. Copyright © 2007 John Wiley & Sons, Ltd.
Pseudo Two-Hop Distributed Consensus Algorithm with Link Failure

For time-delay, noise and network congestion in the communication among agents, there are often random communication link failures among agents. In this paper, we analyze the pseudo two-hop distributed consensus algorithm with link failures, and research the relation between convergence performance and the probability of link failures. Supposing that the probability of link failures in every link is independent identically distributed, we analyze the convergence performance of the pseudo two-hop distributed consensus algorithm with link failures, and simulation results are provided to verify these analytical results.
OPTIMAL MARKDOWN PRICING STRATEGY WITH DEMAND LEARNING

When launching a new product, a firm has to set an initial price with incomplete information about demand. However, after observing the demand over a period of time, the firm might decide to mark down the price, especially when the Bayesian updated belief about demand is lower than originally anticipated. We consider the case in which the manufacturer makes three decisions: initial price, when to mark down the price, and the markdown price. Modeling the cumulative demand as a Brownian motion with an unknown drift, we compute the posterior probability distribution of the unknown drift. We then show that it is optimal to mark down the price when the posterior probability is below a computable threshold. This threshold policy enables us to determine the optimal (a) regular price, (b) markdown price, and (c) markdown time. Additionally, we examine the impact of demand volatility and evaluate the value of learning.
The Evaluation of the Effective Kinetic Parameters and Reactivity of the IPEN/MB-01 Reactor for the International Reactor Physics Experiment Evaluation Project

Abstract The evaluation of the experiments of the effective delayed neutron parameters and reactivity performed in the IPEN/MB-01 research reactor facility has been successfully accomplished. The evaluated data are of very good quality and fulfill the requirements of a benchmark. The recently released MCNP6 together with the ENDF/B-VII.1, JENDL-4.0, JEFF-3.1. 1, ENDF/B-VII.0, and JENDL-3.3 nuclear data libraries has been employed to calculate the effective delayed neutron parameters adopting the benchmark model of the IPEN/MB-01 reactor available in the International Handbook of Reactor Physics Benchmark Experiments. The analysis reveals that all these nuclear data libraries produced satisfactory results for ²eff, ²eff/ᴧ, and ᴧ. The same cannot be said for determining the reactivity using the Inhour equation. It was shown that there is a clear tendency to increase the deviation with the absolute value of the reactivity for negative periods. Only JENDL-3.3 and JEFF-3.1. 1 produced results that are inside the 3σ range of the benchmark value uncertainty. Specifically for the case of ENDF/B-VII.1, a good part of this discrepancy is due to the decay constant of the first group of delayed neutrons, which is overestimated according to the experimental value measured in the IPEN/MB-01 reactor.