Miracle-dz/UniFAR-FTUs huggingface dataset:
Tuning the painter's palette: subtle steric effects on spectra and colour in conjugated electrochromic polymers

A series of vibrantly coloured π-conjugated electrochromic polymers (ECPs) were designed and synthesized with the goal of extracting structure–property relationships from subtle changes in steric strain or relaxation. These are soluble all donor, electron rich, alternating polymers based on repeat units of 3,4-ethylenedioxythiophene (EDOT), 3,4-propylenedioxythiophene (ProDOT), and an acyclic dioxythiophene (AcDOT) in varying combinations to tune steric interactions and the subsequent optical absorption for fine colour control. Two families of polymers were formed where ProDOT2–EDOT, ProDOT–EDOT, and ProDOT2–EDOT2 constitute new shades of blues while AcDOT2–ProDOT, AcDOT–ProDOT, and AcDOT–EDOT yield new hues of magentas with the homopolymers of ProDOT and AcDOT and the copolymer AcDOT2–EDOT2 serving as comparisons. The polymers were synthesized using direct (hetero)arylation polymerization. Examinations of the optoelectronic properties via cyclic voltammetry, spectroelectrochemistry, and colorimetry show that by subtly varying the level of steric relaxation or strain in the form of EDOT or AcDOT content, lower or higher energy absorption transitions are produced respectively. This increase in relaxation or strain allows more short or long wavelength light to transmit, giving new shades of blues or magentas respectively. Since these are all donating polymers, they exhibit changes in contrast no less than 70% at the λmax with the exception of AcDOT–EDOT. The most desirable electrochromic properties were achieved with ProDOT2–EDOT2 and AcDOT2–ProDOT, with band gaps (Eg) and neutral state L*a*b* colour values (−a* and +a* correspond to green and red and −b* and +b* correspond to blue and yellow respectively and L* represents the lightness) of 1.74 eV, 37, 12, −63 and 2.01 eV, 56, 59, −16 respectively. The highly transmissive oxidized state colour values for ProDOT2–EDOT2 and AcDOT2–ProDOT are 92, −3, −3 and 91, −2, −1 respectively. These structure–property relationships grant a greater ability to tune light absorption across the visible, with colour properties similar to ECPs made through other methods without using donor–acceptor effects. This all donor steric tuning method leads to considerably higher levels of transparency when the polymers are fully oxidized.
pH Control Using PI Control Algorithms With Automatic Tuning Method

pH control is quite difficult due to the non-linearity of the neutralization process. In this case, tuning the standard PI controller is a must to achieve a stable feedback A response. This paper, thus, addresses the application of an automatically tuned PI algorithm to stabilize the pH-value of a pH neutralization process. The proposed adapted PI algorithm uses a simple model for the process to predict the pH closed-loop response and its sensitivity to the PI settings. The information obtained is directly used to adjust the PI tuning parameters online in order to produce a pH response that satisfies a pre-defined time-domain specification. The simulation results of the proposed method are compared with those obtained by the standard PI, gain scheduling (GS) and globally linearizing (GLC) algorithms. The comparison showed a successful and promising implementation of the proposed strategy.
Fatigue Behavior of Ti-6Al-4V

Low-cycle-fatigue texts in vacuum and air were performed. Under cyclic loading the Ti-6Al-4V showed both cyclic hardening and cyclic softening depending on heat treatment, stress amplitude, and microstructure. Plastic deformation of the β-phase in the unaged condition due to stress induced martensitic transformation caused cyclic hardening. Cyclic softening was observed if the α-phase hardened by coherent Ti3Al particles was plastically deformed. Equiaxed microstructures exhibited a stronger cyclic softening than lamellar structures. This behavior could be explained by the pronounced texture of the equiaxed microstructures, whereas the lamellar structures were texture-free. The fatigue life was influenced by the cyclic softening process mainly in the low-cycle-fatigue regime. The fatigue life at normalized stress amplitude (σa/σy) was shorter for microstructures with strong cyclic softening as compared to microstructures with lower cyclic softening. Ermudungsverhalten der Legierung Ti-6AI-4V Es wurden Wechselverformungsversuche (LCF) in Vakuum und Luft durchgefuhrt. Unter zyklischer Beanspruchung trat in der Ti-6Al-4V in Abhangigkeit von der Aushartung, der Spannungsamplitude und der Mikrostruktur sowohl Verfestigung als auch Entfestigung auf. Die plastische Verformung der β-Phase verursachte im ungeharteten Zustand infolge der spannungsinduzierten martensitischen Umwandlung eine zyklische Verfestigung. Zyklische Entfestigung wurde gemessen, wenn die durch koharente Ti3Al-Teilchen ausgehartete α-Phase plastisch verformt wurde. Die globularen Gefuge zeigten eine starkere zyklische Entfestigung als die lamellaren Gefuge. Dieses Verhalten konnte dadurch erklart werden, das die globularen Gefuge eine ausgepragte Textur besasen, wahrend die lamellaren Gefuge texturlos waren. Im Bereich der Kurzzeitermudung (LCF) wurde die Lebensdauer entscheidend vom Entfestigungsverhalten bestimmt. Die Gefuge mit starker zyklischer Entfestigung zeigten bei Berucksichtigung der unterschiedlichen Elastizitatsgrenzen (Normierung σa/σy) geringere Bruchlastspielzahlen als die Gefuge mit schwacherer zyklischer Entfestigung.
Triboelectric Separation of Three-Component Plastic Mixture

The results of an experimental study on the triboelectric separation of one type of plastic from a three-component plastic mixture are presented. A triboelectric separator, which consists of a vibratory conveyor equipped with two electrodes, was used. The separation method makes it possible to avoid the adhesion of oppositely charged particles. Separation tests were performed on two kinds of mixtures. The effect of operating parameters such as electric field strength, polarity of applied voltage, and triboelectric charging time on the separation efficiency was examined. In the case of the separation of a mixture of 50% polyvinyl chloride (PVC), 50% polyethylene terephthalate (PET), and 50% polyethylene (PE), the purity of the extracted PVC was larger than 99% for a recovery rate of 94.9%. In the case of the separation of a mixture of 50% acrylonitrile butadiene styrene (ABS), 50% polypropylene (PP), and 50% polystyrene (PS), the purity of the extracted ABS was larger than 99% for a recovery rate of 89.4%.
Formalisation et implantation d'une politique de sécurité d'une base de données

La conception d'un programme charge du controle d'acces d'un systeme gerant de l'information doit s'effectuer selon des regles de programmation strictes, afin d'eviter la presence de failles dans ce programme. L'Atelier Focal est un environnement permettant d'ecrire, au sein d'un meme cadre de travail, des specifications formelles et du code fonctionnel respectant ces specifications. Nous avons utilise cet outil pour formaliser une politique de controle d'acces, celle de Bell & La Padula, et l'implanter dans MySQL, un systeme de gestion de base de donnees. Cette implantation, necessitant la traduction des requetes SQL en termes d'acces Bell & La Padula, se fait sous la forme d'un module externe a la base de donnees qui filtre les requetes, et rejette ainsi celles qui violent la politique de securite.
Remarkable enhancement in dehydrogenation of MgH2 by a nano-coating of multi-valence Ti-based catalysts

A Ti-based multi-valence catalyst was coated on the surface of ball milled Mg powders (∼1 μm in diameter), aiming to decrease the desorption temperature and increase the kinetics of hydrogen release from MgH2 by its catalytic effect on thermodynamics. The catalysis coating was prepared by the chemical reaction between Mg powders and TiCl3 in THF solution, which is ∼10 nm in thickness and contains multiple valences in the form of Ti (0), TiH2 (+2), TiCl3 (+3) and TiO2 (+4). It is believed that the easier electron transfer among these different Ti valences plays a key role in enhancing the hydrogen recombination for the formation of a hydrogen molecule (e.g.). This recombination is generally regarded as the key barrier for hydrogen desorption of MgH2. Experimentally, temperature-programmed desorption (TPD) and isothermal dehydrogenation analysis demonstrate that the MgH2 – coated Ti based system (denoted as Mg–Ti) has excellent dehydrogenation properties, which can start to release H2 at about 175 °C and release 5 wt% H2 within 15 min at 250 °C. The dehydrogenation reaction entropy (ΔS) of the system is changed from 130.5 J K−1 mol−1 H2 to 136.1 J K−1 mol−1 H2, which reduces the Tplateau to 279 °C at an equilibrium pressure of 1 bar. A new mechanism has been proposed that multiple valence Ti sites act as the intermediate for electron transfers between Mg2+ and H−, which makes the recombination of H2 on Ti (in forms of compounds) surfaces much easier.
Physico-Chemical Studies of Tris (adamantan-1-aminium) Hexachlorostannate (IV) Chloride Monohydrate

The structural characteristics of organic ammonium salts of the hexahalogenostannates (IV) with a general formula (R-NH 3)3SnX 6 have not yet been studied extensively. In the course of investigating these types of materials, the title compound, a double salt of adamantan-1aminium chloride and hexahalogenostannate (IV), with the formula (C 10 H18 N) 3[SnCl 6]Cl·H 2O, was crystallized. Its asymmetric unit contains three independent cations of protonated adamantan-1-amine, one chloride anion, one Hexachlorostannate (IV) ion and a hydrate water molecule. The atomic arrangement can be described as inorganic SnCl 6 2- units isolated from each other by the organic cations, the chloride anions and the cocrystallized water molecules. The compound exhibits bifurcated and simple hydrogenbonding interactions between the ammonium groups, the water molecules and the chlorine atoms, with little variation in the hydrogen-bonding interactions. The 119 Sn, 13 C and 15 N CPMAS NMR spectra are in agreement with the X-ray structure.
Fluorenylhydroxamic acids isomeric with the carcinogens N-fluoren-2-ylacetohydroxamic acid. Part I. Synthesis of N-fluoren-1-yl-, N-fluoren-3-yl-, and N-fluoren-4-ylacetohydroxamic acid

Three new fluorenylhydroxamic acids isomeric with the carcinogen N-fluoren-2-ylacetohydroxamic acid have been synthesized by partial catalytic reduction of the corresponding nitrofluorenes, prepared in turn by oxidation of the respective fluorenamines with peroxymaleic acid. A route to N([1-14C]fluoren-1-yl)acetamide and -acetohydroxamic acid by aromatization of the oxime of 3,4-dihydrofluoren-1 (2H)-one by the Semmler–Wolff rearrangement has been explored. Analysis of the products by t.l. c. indicated the imine as an intermediate when this oxime was rearranged in the presence of limited amounts of acetic anhydride.
Statistical Analysis of the Effect of the Temperature and Inlet Humidities on the Parameters of a PEMFC Model

An individual PEM fuel cell 6‐parameter mechanistic model was developed. In parallel, experimental polarization curves were obtained at different temperature and inlet gas humidities conditions. The 6 model parameters were determined by fitting the semi empirical model to the experimental curve using a non linear regression method. Finally, a statistical analysis was carried out in order to determine which operating conditions (temperature and inlet humidities) have a significant effect on which model parameters. A black box model was built in order to relate the model parameter values to the significant operating conditions for each one of them. The obtained model was able to satisfactory reproduce the experimental behaviour of the system at low current densities.
The current–voltage characteristic of the ideal two‐terminal tandem solar cell

An ideal tandem solar cell, with an infinite number of diodes, has the same limit efficiency whether or not the diodes are connected electrically in series. In case of a series connection, the device has a single current–voltage characteristic. The latter can easily be deduced, and its efficiency therefore can easily be calculated. Copyright © 2003 John Wiley & Sons, Ltd.
Adsorptive Removal of Cr(VI) from Aqueous Solution on Hydrous Cerium—Zirconium Oxide. Part I: Process Optimization by Response Surface Methodology

Hydrous cerium–zirconium oxide (Ce0.25Zr0.75O2) was used for Cr(VI) removal by adsorption. The response surface methodology (RSM) was applied as a tool for the optimization of adsorption operational conditions (temperature, pH and adsorbent dose) with the combined effects of the key processing variables on the Cr removal efficiency (%RCr). The following conditions were found to be optimal: pH = 2, temperature = 28 °C, adsorbent dose = 4 g l−1. The %RCr obtained experimentally (92%) was in agreement with the value predicted by RSM (88%). The adsorption process followed the pseudo-second-order kinetic model and obeyed the Langmuir isotherm model. Thermodynamic parameters (ΔH°, ΔS° and ΔG°) indicated the exothermic and spontaneous nature of adsorption governed by physisorption interactions. Hydrous Ce0.25Zr0. 75O2 showed high adsorption capacity (25 mg g−1), high desorption efficiency (80%), reached adsorption equilibrium quickly (30 minutes) and high chemical stability. The Cr(VI) adsorption on hydrous Ce0.25Zr0. 75O2 was not completely reversible. The reduction of Cr(VI) to Cr(III) under acidic conditions was also responsible for Cr(VI) removal.
PROBABILISTIC SIMULATION OF BATCH TRAY DRYING USING MARKOV CHAINS AND THE MONTE CARLO TECHNIQUE

The objective in food dehydration is to dry the product to a specified uniform moisture content. In practice, a distribution in final moisture content is unavoidable, arising from the intrinsic variability of food properties and the probabilistic nature of the food drying process. A methodology is outlined whereby the inherent stochastic dynamics of batch tray dehydration in cabinet or tunnel dryers can be modeled efficiently using Markov chains. By simulating the drying process with the model, the progressive transformation of the moisture distribution of the trays throughout the drying cycle can be quantified. Output from the model is validated with experimental drying results to test its accuracy. In addition the output of the Markov approach is compared with that of an equivalent Monte Carlo simulation model to provide inter-model comparisons. Markov analysis can predict the variation in final moisture content and thus has the potential to help maximize the value of the dried product.
Supramolecular architecture of bis­(melaminium) l-tartrate 2.5-hydrate

In the crystal structure of the title compound, 2C(3)H(7)N(6)(+) center dot C4H4O62- center dot 2.5H(2)O, the melaminium ions form infinite tapes via N-H center dot center dot center dot N hydrogen bonds. The tartrate anions, lying on twofold rotation axes, are arranged in linear arrays. The crystal packing is stabilized by an extensive net of hydrogen bonds leading to a supramolecular architecture.
Tight-binding molecular dynamics in liquid III-V compounds. I. Potential generation

We present a novel tight-binding scheme designed for total-energy and molecular-dynamics simulations in III-V compounds. The role played by orbital overlap and charge transfer is critically addressed and suitably modelled. Comparisons to first-principles density-functional and Hartree-Fock data are presented and commented on in view of the interpolative character of the present method.
Rf microelectromechanical system device with a lateral field-emission detector

We propose a micromachined device that utilizes the field-emission (FE) phenomenon as a mean to modulate signal for radio-frequency microelectromechanical system applications. In this article, we present the stationary reference (SR) device and the resonator-embedded (RE) device and compare their field-emission performances. The SR device contains no moving part and is used to examine the conditions to excite field emission. The RE device has an embedded microresonator of bandpass filter characteristic. Due to enhanced tip sharpness and closer gap, initial results show that compared to the SR device, the FE current of the RE device has been increased by 192 times under the same anode-cathode potential difference of 240V and 2×10−8Torr vacuum level.
Third-order elastic constants of orthorhombic calcium formate

All 20 independent third-order elastic constants (TOEC) of orthorhombic calcium formate, Ca(HCOO)2, Ca2+. C2H2O2-4, space group Pcab, have been determined with the aid of stress-induced shifts of ultrasonic resonance frequencies. Longitudinal and transverse effects possess negative values indicating the high stability of calcium formate over a wide pressure range. The anisotropy of TOEC, characterized by --c111 > --c333 > --c222, corresponds with the anisotropy of second-order elastic constants (c11 > c33 > c22). The value 5.22 for the pressure derivative of the inverse bulk compressibility coincides with the quasi- invariant value of ca 5 observed in most stable cubic crystals so far investigated. There exists a pronounced departure from third-order Cauchy relations: the 'transverse' constants exceed the corresponding 'shear' components considerably in absolute magnitude in accordance with the behaviour of the second-order Cauchy relations. These effects are explained as originating from the non-centrosymmetric formate ions. A comparison of TOEC of calcium formate and cubic calcium fluoride confirms the typical contribution of the formate ions to the third-order elastic behaviour.
The Alignment of Lyotropic Liquid Crystals Formed by Hexadecyltrimethylammonium Bromide in D2O in a Magnetic Field

The alignment of lyotropic liquid crystals formed by hexadecyltrimethylammonium bromide (CTAB, where C stands for cetyl) with D2O was studied by the use of 2H NMR. At CTAB/D2O concentrations between 1.01 and 1.29 mol/kg, liquid crystal domains aligned in the magnetic field within a few hours. The dependence of the characteristic alignment time on concentration and temperature has been determined. At higher concentrations, no alignment took place due to the high viscosity of the system. At lower concentrations, the alignment could not be observed by 2H NMR. The addition of sodium salicylate (NaSal), at equal molar concentrations of CTAB and NaSal, changed the orientation of the micelles from parallel to the magnetic field to perpendicular to the field. Line-shape simulations were carried out to give estimates on the rate of exchange between free D2O molecules and those bounded to the micelles, as well as on the deuterium quadrupole splittings for D2O molecules bound to micelles. The dependence of the chara.
Polyacrylonitrile/graphene composite as a precursor to a sulfur-based cathode material for high-rate rechargeable Li–S batteries

Polyacrylonitrile/graphene (PAN/GNS) composites have been synthesized via an in situ polymerization method for the first time, which serve as a precursor to prepare a cathode material for high-rate rechargeable Li–S batteries. It is observed from scanning electron microscopy (SEM) and transmission electron microscopy (TEM) that the PAN nanoparticles, less than 100 nm in size, are anchored on the surface of the GNS and this unique structure is maintained in the sulfur composite cathode material. The electrochemical properties of the pyrolyzed PAN-S/GNS (pPAN-S/GNS) composite cathode have been evaluated by cyclic voltammograms, galvanostatic discharge–charge cycling and electrochemical impedance spectroscopy. The results show that the pPAN-S/GNS nanocomposite, with a GNS content of ca. 4 wt. %, exhibits a reversible capacity of ca. 1500 mA hg−1sulfur or 700 mA hg−1composite in the first cycle, corresponding to a sulfur utilization of ca. 90%. The capacity retention is relatively stable at 0.1 C. Even up to 6 C, a competitive capacity of ca. 800 mA hg−1sulfur is obtained. The superior performance of pPAN-S/GNS is attributed to the introduction of the GNS and the even composite structure. The GNS in the composite materials works as a three-dimensional (3-D) nano current collector, which could act not only as an electronically conductive matrix, but also as a framework to improve the electrochemical performance.
Environmental exposure to lead could enhance susceptibility to oxidative stress in patients with pollenosis

The parameters of oxidative stress (MDA, SOD, GPx, H 2 O 2 , GSH) and metals concentration were measured on a pollen-allergic sample (64 people) and the correlation between parameters were examined. There were no differences in parameters between pollenotics and control (35 people) except for the level of reduced glutathione which was statistically significant lower at pollenotics. There were no differences in the level of metals in blood or hair. The statistically significant correlation between Pb and SOD (r = 0.74 p = 0.000) at pollenotics suggests that environmental exposure to lead could stimulate the intensity of hay fever symptoms connected with free radicals processes.
Synthesis of 1- and 1,2,2'-deuteriated deoxyribose and incorporation into deoxyribonucleosides

Thymidine, deoxycytidine, deoxyadenosine, and deoxyguanosine have been prepared with deuterium substitution at position 1' and at positions 1', 2', and 2'' from deuteriated deoxyribose. The synthetic strategy involved reduction of the bis(tert-butyldimethylsilyl) derivative of 2-deoxyribonolactone with Dibal-D followed by deprotection (HCl/MeOH and tetrabutylammonium fluoride) to give 1-deuterio methyl glycoside which was converted to the 1-deuterio 3,5-ditoluoyl methyl glycoside. Preliminary exchange of 2-deoxiribonolactone with NaOMe/MeOD brought about 2,2'-dideuteriation; treatment as above gave the 1,2,2'-trideuterio 3,5-ditoluoyl methyl glycoside
A DVD Spectroscope: A Simple, High-Resolution Classroom Spectroscope

A new, simple, inexpensive spectroscope for classroom experiments, a DVD spectroscope, is described and some emission spectra observed with the spectroscope are presented. This spectroscope is made with a sheet of cardboard, or an empty box, and a digital versatile disk (DVD). The quality of the spectra is much improved compared to that obtained by compact disk (CD) spectroscopes and DVD spectroscopes reported earlier. The resolution of this spectroscope is high enough to distinctly resolve the two yellow spectral lines of mercury at 577 and 579 nm. One can also observe clearly many Fraunhofer lines in the sunlight spectrum. Photographs of spectra are easily taken with a digital camera. Such images can be displayed on a monitor in real time, which helps students understand what is observed in the spectroscope.
Predicting Active Material Utilization in LiFePO4 Electrodes Using a Multiscale Mathematical Model

A mathematical model is developed to simulate the discharge of a LiFePO 4 cathode. This model contains three size scales, which match with experimental observations present in the literature on the multiscale nature of LiFePO 4 material. A shrinking core is used on the smallest scale to represent the phase transition of LiFePO 4 during discharge. The model is then validated against existing experimental data and this validated model is then used to investigate parameters that influence active material utilization. Specifically, the size and composition of agglomerates of LiFePO 4 crystals is discussed, and we investigate and quantify the relative effects that the ionic and electronic conductivities within the oxide have on oxide utilization. We find that agglomerates of crystals can be tolerated under low discharge rates. The role of the electrolyte in limiting (cathodic) discharge is also discussed, and we show that electrolyte transport does limit performance at high discharge rates, confirming the conclusions of recent literature.