Miracle-dz/UniFAR-FTUs huggingface dataset:
Tunable all epitaxial semimetal-semiconductor schottky diode system : ErAs on InAlGaAs

We report the growth, fabrication, and electrical properties of a fully epitaxial semimetal-semiconductor Schottky diode materials system: ErAs on InAlGaAs. The coherent, thermodynamically stable, lattice-matched interface eliminates oxide and interfacial third phases, making the Schottky barrier height and associated electrical parameters dependent on the fundamental molecular bonding (e.g., interface dipoles) rather than unintentional extrinsic effects. ErAs:InAlGaAs diodes thus have highly tunable properties; by adjusting composition, doping, and interface type, the Schottky barrier height is tunable from ∼100meVto∼620meV, short circuit responsivity is tunable from 0.5to19A∕W, differential resistance is tunable from 103to1010Ωμm2, and capacitance is tunable from 0.4to2fF∕μm2. Rectification of a rf source has been demonstrated up to 20GHz. ErAs:InAlGaAs is thus a very promising materials system for design of an upper mm-wave, zero-bias, square-law detector with a significantly reduced noise floor.
THE EFFECT of MODIFIED ATMOSPHERE PACKAGING ON the MICROBIAL ECOLOGY IN REQUEIJÃO, A PORTUGUESE WHEY CHEESE

The effects of modified atmosphere packaging on growth of adventitious microorganisms in Portuguese whey cheese (Requeijao) were studied following a response surface methodology using storage time (2, 6, 10 and 15 days), storage temperature (4, 12 and 18C) and fraction of CO 2 in the overhead gaseous mixture also containing nitrogen (0, 50 and 100%) as manipulated variables. The viable numbers of Enterobacteriacea, staphylococci, yeasts and spore-forming bacteria in the experimental whey cheeses did not increase within 15 days when storage was at 4C under 100% CO 2 : those of enterococci increased significantly after 6 days under similar conditions, and a similar inhibiting effect was observed against Bacillus, pseudomonads, lactobacilli and streptococci. It was observed that 100% N 2 at 4C was able to completely inhibit growth of staphylococci, lactobacilli and Bacillus for 2 days. The loci (and the nature) of the optima in terms of manipulated variables were obtained for all microbial groups studied. No true overall minimum was found, but storage conditions preset at 4C and 100% CO 2 led to a 15 day extension of the shelf-life of Requeijao.
Separation of Molecular-Size Classes of Aquatic Humic Substances Using Ultrafiltration and Dialysis

Abstract A procedure for separating aquatic humic substances into discrete molecular size fractions by the combined use of ultrafiltration and dialysis was tested. The molecular size distributions of separated fractions were examined by application of samples to a gel filtration chromatography column. Variations in the elution patterns observed for the separated fractions of small and intermediate molecular size were largely consistent with predicted effects of separation procedures. In contrast, humic substances of large molecular size were not separated effectively by dialysis using dialysis membranes of large molecular weight cut‐off. Small quantities of humic material of large molecular size were observed in most of the ultrafiltrates. This phenomenon may have been an artefact of filtration and/or the result of reconfiguration of material after separation.
Mechanism of Charge Migration through DNA: Molecular Wire Behavior, Single-Step Tunneling or Hopping?

In this work the mechanism of migration of positive charges through donor−DNA−acceptor systems is studied using a quantum mechanical model based on the tight-binding approximation. For DNA bridges containing only adenine-thymine (AT) base pairs the difference in ionization potential between the donor moiety and the AT base pairs (i.e., the injection barrier) is shown to determine the mechanism by which the charge migrates from the donor to the acceptor. For an injection barrier of 0.55 eV, corresponding to a guanine radical cation as the hole-donor, a β-value of 0.85 A-1 is found. This agrees reasonably with the value of β = 0.7 A-1 deduced from experimental studies on these sequences. For this injection barrier (0.55 eV) the charge density on the AT bridge was found to be very small, which is characteristic for charge transfer by single-step tunneling. For lower injection barriers the charge density on the AT bridge becomes substantial and the charge moves through the bridge according to a bandlike mecha.
Structure/Property Relationships for Poly(Vinylidene Fluoride)/Doped Polyaniline Blends

Poly(vinylidene fluoride) (PVDF) and its blends with polyaniline (PANI) doped with dodecylbenzene sulfonic acid (DBSA) were characterized by electrical conductivity, differential scanning calorimetry (DSC) and X‐ray scattering techniques. The onset of an infinite cluster (InC) of conducting, highly anisometric PANI/DBSA particles in PVDF/(PANI/DBSA) blends was observed at the percolation threshold as low as w*≈3.5 wt. %. The small angle X‐ray scattering (SAXS) data confirmed the expected spatial organization of PANI/DBSA needles into fractal‐like structures above w*. A slight decrease of both the DSC and the wide‐angle X‐ray scattering (WAXS) degrees of crystallinity of PVDF with the PANI/DBSA mass content w was explained by strong interactions at the PVDF/(PANI/DBSA) interface resulting in the loss of crystallizability of a fraction of sterically immobilized chains of PVDF in boundary layers around PANI/DBSA particles. The available data suggest that the conductive paths within InC of PANI/DBSA in PVDF/(P.
Plasma‐Mediated Modification of Austenitic Stainless Steel: Application to the Prevention of Yeast Adhesion

The work is focused on defining a stainless steel surface treatment to prevent microbial adhesion. The yeast Saccharomyces cerevisiae was selected as the model for eukaryotic cells. Different surface cleaning procedures, including chemical and plasma-mediated treatments, were studied. Detachment experiments displayed no modification in yeast adhesion, despite significant variations in the physico-chemical properties of the solid surface. Plasma-mediated thin coatings (≈375 nm) were then deposited on stainless steel applying hexamethyldisiloxane/ oxygen plasma. FT-IR study revealed a dense Si-O-Si network, while XPS analysis detected no more iron or chromium at the extreme surface. Detachment experiments demonstrated that these films were successful in preventing cell adhesion, due to a barrier effect.
Evolution of cadmium and lead contents in Antarctic coastal seawater during the austral summer.

Abstract The seasonal evolution of the cadmium and lead distribution in the water column of the Gerlache Inlet (Ross Sea) was studied during the 1990–91 austral summer. Measurements were carried out by Anodic Stripping Voltammetry in Antarctica immediately after the collection and filtration of samples. The concentrations of both metals were homogeneous before the phytoplankton bloom with mean values of 0.71 (SD 0.10) and 0.116 (SD 0.014) nmol/1 for cadmium and lead respectively. A subsequent depletion in metal concentration was observed in the shallow waters. The surface concentration of cadmium decreased to about 0.1 nmol/1 at the end of the season. The vertical distribution of lead was less affected by the seasonal evolution and the mean surface concentration decreased to 0.044 nmol/1 in the same period. The results are evaluated with respect to physical and biological processes in the area examined and compared with those obtained on previous expeditions in the same area.
Quenched versus thermal disorder in crack propagation: size (and scales) matter.

The slow propagation of crack in heterogeneous material is of fundamental importance for the failure of engineering structure and of natural system, such as seismic faults. Owing to the many interacting processes at play, it however still remains a challenge to describe the precise mechanical formulation that governs the dynamics of such systems. Previous studies dedicated to this issue have mostly been restricted to the zero temperature limit, giving rise to extremal dynamics, or to systems with short range interactions. Here we incorporate in a numerical model of slow crack growth the effect of temperature and long range elastic interactions. This approach provides a more realistic model of crack propagation in heterogeneous media under natural conditions. We adopt the configuration of an interfacial crack system, similar to a designed experimental setup. We recover both at the macroscopic and at the microscopic scales all the reported experimental observations. Namely we are able to observe a similar macroscopic crack evolution, a similar morphology of the crack front line and a similar distribution of local speeds: a self affine morphology with roughness exponent around 0.5 at small scale, and a lower effective roughness at larger scale for the front morphology [1], and a non Gaussian power law velocity distribution, with a fat tail P (v) v−2.6 at large speeds [2,3].
Preparation of Core-Shell SAPO-34 Adsorbent on Ceramic Particles; Improvement of CO2 Separation from Natural Gas

Fine crystals of SAPO-34 were synthesized by preparation of sol-gel precursor and hydrothermal process. The produced crystalline phase and the crystal shapes were analyzed by XRD patterns and SEM images. The core-shell adsorbent was prepared by the formation of the fine layer of SAPO-34 on the surface of the inert ceramic particles using the same synthesis parameters and hydrothermal conditions by in situ crystallization. The prepared core-shell SAPO particles were tested in dynamic adsorption experiments of a mixture of 5% CO2 and 95% CH4 at 298 K and 0.1 MPa, and their performance was compared with pure powders of SAPO-34 in the same adsorption operational conditions. The longer breakthrough time, sharper breakthrough curves, and higher CO2 adsorbed amount were observed using core-shell SAPO-34 particles as adsorbent rather than using pure particles of SAPO-34. It is concluded that the production of a thin layer of SAPO-34 on cheap and inert porous ceramic particles is preferred rather than using higher amounts of SAPO-34 powders pelleted or binded with inert material in dynamic adsorption processes for the separation of CO2 from natural gas.
Multiple Marker-Based Evaluation of Kalanchoe pinnata, Bombax ceiba, and Morus alba Leaves: Quantification of α-Amyrin, Lupeol, and β-Sitosterol Using High-Performance Thin-Layer Chromatography

Kalanchoe pinnata (Crassulaceae), Bombax ceiba (Bombaceae), and Morus alba (Moraceae) are important drugs in Indian and Chinese Systems of Medicine. Leaves of K. pinnata are reported to show anti-inflammatory, antifungal, and antibacterial activity and are reported to contain quercetin, kaempferol, α-amyrin, β-sitosterol, ferulic, and caffeic acid. Leaves of B. ceiba are reported for the treatment of diarrhea, dysentery, gonorrhea, and bladder ulceration and are reported to contain shamimin, lupeol, β-sitosterol, and α-amyrin. Leaves of M. alba are reported to show anti-inflammatory, emollient, hypolipidemic, and diuretic activity and are reported to contain quercetin, rutin, moracetin, and artocarpin. In the present work, a method for simultaneous quantification of three marker compounds, viz., α-amyrin, lupeol, and β-sitosterol from the leaves of K. pinnata, B. ceiba, and M. alba was developed and validated as per International Conference on Harmonization (ICH) guidelines. This is the first report of simultaneous quantification of these three compounds. α-Amyrin, lupeol, and β-sitosterol resolved at RF 0.71, 0.28, and 0.16, respectively, on thin-layer chromatography (TLC) when developed in the solvent system of toluene—ethyl acetate (9.5:0.5). The linearity range for α-amyrin, lupeol, and β-sitosterol was found to be 160–560, 150–900, and 80–480 ng spot−1, respectively, with correlation coefficients (r values) of 0.999, 0.997, and 0.995, respectively. The amount of α-amyrin, lupeol, and β-sitosterol were found to be in range of 0.013–0.047, 0.046–0.318, and 0.028–0.123 % w/w, respectively. The developed methods were found to be accurate, precise, and reproducible and can be used for routine quality control of herbal material and formulations containing K. pinnata, B. ceiba, and M. alba.
Synthesis of brushite nanoparticles at different temperatures

Phase pure, stable nanocrystalline brushite particles with average diameter in the range of 23–87 nm were obtained by the reverse microemulsion technique employing a mixture of surfactants (Aliquat 336 & Tween 80) as template directing agents, and calcium nitrate tetrahydrate and biammonium hydrogen phosphate as precursors. Particle sizes and morphologies were tuned by adjusting the reaction parameters, precursor concentration and temperature. FTIR, TEM, and XRD were used to characterize morphological changes of as synthesized nanoparticles. FTIR and XRD analyses confirmed the formation of brushite nanoparticles. Variations in the reaction temperature resulted in changes in the particle morphology and distribution. At high temperatures (60°C), the sample exhibited high monodispersity and spherical morphology with the average grain size of 42 nm. At low temperatures (6°C), nanoflakes were formed. The results suggest that a reverse microemulsion system provides facile media for control of the phase and morphology of nanoscale calcium phosphate biominerals. A mechanism providing an insight into the formation of brushite particles has also been proposed.
High pressure luminescence of indole and substituted indoles in liquid solution

High pressure luminescence measurements have been made on indole, 5‐methoxyindole, and tryptophan in a number of solvents. Radiative and nonradiative rates have been calculated as a function of pressure. It has been shown that the nonradiative rates are determined by viscosity in all solvents except water and, to some extent, methanol for which the peak shift as well as possibly viscosity are the controlling factors. The radiative rates and the peak position and shift have been scaled with the dielectric constant in a continuous and consistent way. Some peculiarities have been observed when water and methanol are used as solvents.
Low temperature Si3N4 direct bonding

Extremely strong bonds can be formed between smooth, clean layers of Si3N4 at temperatures ranging between 90 and 300 °C. These bonds have been formed between Si3N4 layers deposited on various substrates with deposition temperatures as low as 300 °C. The bond is initially formed at room temperature and subsequently annealed at temperatures ranging between 90 and 300 °C. Thus, the materials bonded in this manner are never exposed to temperatures higher than 300 °C. This low temperature bond greatly expands the range of applications of direct bonding which had heretofore been restricted by the temperatures of 700 to 1000 °C required by conventional wafer bonding.
Bright Future for Fluorescence Blinking in Semiconductor Nanocrystals

This Perspective describes recent progress and current challenges toward achieving a detailed understanding of fluorescence blinking in colloidal semiconductor nanocrystals (NCs). Many current models hypothesize that the NC’s nonemissive OFF state originates from a charge-separated state of the NC. This link suggests two possible approaches to minimize NC blinking, first by suppressing the pathway which leads to the NC’s charge-separated state and second by modifying the NC’s fundamental properties in order to weaken its intrinsic nonradiative processes when trapped charge is present. Examples and current challenges associated with each of these approaches are discussed. Recent efforts highlight the progress that has been achieved toward the ultimate goal of eliminating NC blinking entirely.
Aggregation of a semifluorinated n-alkane in perfluorooctane

The phase behavior of solutions of two semifluorinated n-alkanes, heptadecafluorotetracosane (F(CF[sub 2])[sub 8](CH[sub 2])[sub 16]H) and pentacosafluorooctacosane (F(CF[sub 2])[sub 12](CH[sub 2])[sub 16]H), in perfluorooctane and isooctane is studied. Viscosity, dynamic light-scattering, and small-angle neutron-scattering data show the presence of small, nearly spherical aggregates in heptadecafluorotetracosane/perfluorooctane solutions in the liquid phase above the critical micelle concentration. The authors determined the size and average aggregation number of these aggregates as a function of the fluorohydrocarbon concentration. Small-angle neutron-scattering results show that the perfluorooctane solvent penetrates appreciably into the micellar core. 21 refs., 6 figs., 2 tabs.
Use of the Solubility Domain Approach for the Modeling of the Hydroxide Precipitation of Heavy Metals from Wastewater

The use of the solubility domain approach for providing representative effluent treatment quality assurance standards for the hydroxide precipitation of Zn2+, Pb2+, and Fe3+ from various wastewater composition types has been modeled and experimentally validated. Solubility domain calculations were based on the precipitated phases isolated from systems representing the upper and lower limits of potential effluent chemical compositions. All such phases resembled their mineralized counterparts with a lower degree of structural order. For all systems modeled, the experimentally observed solubilities were generally encompassed within the predicted solubility domains. Validation of the approach using real treatment data demonstrated the effectiveness of the solubility domain method in predicting optimum operating condition ranges for wastewater treatment. Prediction accuracy was largely dependent on the nature of the solubility-limiting phase. With the exception of carbonate-rich systems, changes to the aqueous.
The utilization of the bubble pressure dependent harmonic resonance frequency for enhanced heating during high intensity focused ultrasound treatments

The use of bubbles in High Intensity Focused Ultrasound (HIFU) enhances tissue heating; however, localization of the treatment is difficult due to harmful effects at non-focal regions. In this study the bubble dynamics were studied through the utilization of resonance curves and bifurcation diagrams of the normalized bubble oscillation amplitude (NBOA) (time varying radius/initial radius) by solving the Hoff model. This method allowed us to study the bubble dynamics in wide ranges of control parameters. Results indicate that, by sonicating the bubbles with their pressure dependent harmonic resonance frequency (e.g. 3.1 MHz for a 5 micron bubble with shell shear modulus of 50 MPa and 100nm thickness), the (NBOA) is negligible below a threshold pressure (PT) (∼1.5 MPa). For pressures above the PT, the NBOA increases and remains constant for a large pressure range concomitant with a significant increase in higher harmonic emissions. Because of the steep spatial pressure gradient of the HIFU transducer, the n.
Theoretical Modelling of Free Falling Wedges Entering the Water Surface: Part I — Wedge Motions

As the first of two companion papers, theoretical models are proposed to describe the motions of free falling wedges vertically entering the water surface at Froude numbers: 1 ≤ Fn < 9 (Here, the Froude number is defined as Display FormulaFn=V0/gc0). The time evolutions of the penetration depth, the velocity and the acceleration are analyzed and expressed explicitly The maximum and average accelerations are predicted. The drag (slamming) coefficients are extensively studied. It is found that for the light wedge the transient drag coefficients have slow variation in the first half stage and rapid variation in the last half stage, and for the heavy wedge the transient drag coefficients vary slowly during the whole stage and can be treated as constant. The theoretical results are compared with numerical simulations by nonlinear BEM (Wang & Faltinsen (2010, 2013)), and good agreements are obtained.Copyright © 2013 by ASME
Geomicrobial Kinetics: Extrapolating Laboratory Studies to Natural Environments

Predicting metabolic rates and population sizes of microorganisms in natural environments is a central problem in geomicrobiology. Such predictions can be made on the basis of a thermodynamically consistent rate law that accounts for both kinetic and thermodynamic controls on microbial metabolism. Application of the rate law requires kinetic and growth parameters, the values of which have been determined for pure and mixed cultures growing in laboratory reactors. However, not all parameter values derived from laboratory studies can be validly applied to the environment. This article illustrates a best-choice approach for extrapolating experimentally-derived parameter values to natural environments, using microbial sulfate reduction coupled to acetate oxidation as an example. We compiled kinetic and growth parameters determined by previous laboratory studies and evaluated their applicability to natural environments. Our results suggest that some parameters, such as rate constants and maximum growth yields, can be applied directly to the environment; others, such as half-saturation constants and specific maintenance rates, are best determined using samples recovered from the environment of interest. The best-choice parameter values were applied to simulation of acetotrophic sulfate reduction in the sediments of a freshwater lake. Our analysis shows that the best-choice approach reduces the tasks of parameter fitting and simplifies the modeling exercise. The proposed approach also ensures that parameters in use are consistent with the physiology of indigenous microorganisms, and relevant to the environment of interest.
Stability of Self-Sustaining Combustion of Energetic Materials with Pronounced Condensed Phase Reactions

Typically, simulations of the combustion of energetic materials have focused on a detailed description of the processes in the gas phase. This is due to an implicit assumption that the burning rate control zone is located in the gas phase at moderate pressures. However, at the present time new arguments in favor of the concept of the condensed phase being the locus of the burning rate control zone for typical energetic materials in “rocket” pressure range have become available. These are based on data of the temperature profiles in the combustion wave of modern energetic materials. Analysis shows that, with pronounced heat release in the condensed phase, self-sustaining combustion can be unstable. This effect may result in the existence of combustion regimes with “cross-surface” combustion waves. The difficulty of formulating a description of the combustion of energetic materials with pronounced condensed phase reactions are discussed.
Phthalates in our food

Phthalates are a group of chemicals used to make plastics softer and more flexible. They are used in hundreds of products, such as vinyl flooring, adhesives, detergents, lubricating oils, automotive plastics, plastic clothes (raincoats) and personal-care products (soaps, shampoos, hair sprays and nail polishes). People are exposed to phthalates by eating and drinking foods that have been in contact with containers and products containing phthalates. To a lesser extent, exposure can occur from breathing in air that contains vapors or dust contaminated with phthalate particles. Once phthalates enter a person's body, they are converted into breakdown products that pass out quickly in urine. However, biomonitoring studies that measure urine metabolites in humans show widespread exposure to phthalates. Phthalates have been labeled as potential endocrine disrupting chemicals (EDCs) because studies have demonstrated that they interfere with hormones of the reproductive system. Recently, we reported for the first time concentrations of phthalates in United States food and used these finding to estimate dietary phthalate intake.1 The estimated intakes for individual phthalates in our study were more than an order of magnitude lower than EPA Reference Doses (RfDs), but more studies are needed to evaluate cumulative exposure to phthalates as byproducts of food consumption.