Miracle-dz/UniFAR-FTUs huggingface dataset:
The stability of ferroelectric polarization of PVDF upon irradiation

Polymeric actuator and sensor materials suffer from a low thermal and temporal stability. We report on an attempt to slow down the underlying structural relaxation in polyvinylidenefluoride (PVDF) films by irradiation with electrons of 1.5 MeV. This treatment yielded a dose-dependent crosslinking of the macromolecular chains. It caused a considerable rise of the ferroelectric remanent and saturation polarization, and the material became a harder ferroelectric. These changes were almost completely and irreversibly lost upon subsequent annealing. Electron spin resonance (ESR) measurements revealed that a large number of radicals and trapped electrons remained after irradiation (/spl sim/1 per crystallite), and that the electric conductivity increased from 0.11 pS/m in the un-irradiated but poled sample to 1.1 pS/m at 450 kGy. The increase in conductivity with dose is caused completely by a corresponding increase of the product /spl mu/n of the charge carrier mobility /spl mu/ and the number density n. Based on a discussion of depolarization effects, we conclude that the change in ferroelectric behavior upon irradiation is caused mainly by the activity of those charges which are implanted or created by irradiation, and that the majority of them are annihilated by thermal treatment. However, the reduction of polarization with time, or at elevated temperature, is considerably slowed down due to the existence of crosslinks.
Relation between chemical composition of oak wood used in cooperage and sensory perception of model extracts

BACKGROUND: Oak extractive substances modify the aroma and taste of ‘oaked’ wines, with an increased intensity of sensory descriptors such as ‘oaky’, ‘spicy’, ‘vanilla’, ‘smoky’, etc. arising during barrel maturation. In this study the relationship between the chemical composition of untoasted oak wood and the sensory assessment of oak extract was investigated. Oak wood samples (140) were analysed both chemically (using gas chromatography/mass spectrometry after extraction with dichloromethane) and using sensory descriptive analysis of oak-extracted model wine solutions. RESULTS: Oak samples from the USA, France and Eastern Europe had different chemical compositions in terms of principal odour-active extractives, and this was reflected by perceived sensory differences. CONCLUSION: The major sensory differences were associated with cis-whisky-lactone concentrations of the wood extracts and were related to sensory descriptors such as coconut, caramel and milk. Other compounds studied (trans-whisky-lactone, eugenol and vanillin) were found to have a minor impact on sensory differences between samples in spite of their odour activity. This fact could be explained by the natural differences between samples not being sufficiently large to be perceived. The effects of aroma amplification and/or masking linked to the presence of other odorous chemicals could also explain these observations. Copyright © 2009 Society of Chemical Industry
An EXAFS spectroscopic study of solvates of copper(I) and copper(II) in acetonitrile, dimethyl sulfoxide, pyridine, and tetrahydrothiophene solutions and a large-angle x-ray scattering study of the copper(II) acetonitrile solvate in solution

X-ray absorption edge and EXAFS spectra of the acetonitrile, dimethyl sulfoxide, pyridine and tetrahydrothiophene solvated copper(I) ions and the acetonitrile and dimethyl sulfoxide solvated copper(II) ions have been measured in solution. Analysis reveals that the copper(I) solvates are most probably tetrahedral, and the following Cu-solvate bond distances have been found: Cu-N = 1.99(2) [angstrom] in acetonitrile, Cu-O = 2.09(4) [angstrom] in dimethyl sulfoxide, Cu-N = 2.06(1) [angstrom] in pyridine, and Cu-S = 2.30(1) [angstrom] in tetrahydrothiophene. The copper(II) solvates are most probably Jahn-Teller distorted octahedrons, and the following equatorial Cu-solvate bond distances have been found: Cu-N = 1.99(1) [angstrom] in acetonitrile, and Cu-O = 1.98(1) [angstrom] in dimethyl sulfoxide. An 1.0 M solution of copper(II) trifluoromethanesulfonate in acetonitrile has been studied by means of the large-angle X-ray scattering technique, and the following Cu-N and Cu-C distances have been found for the Cu(CH[sub 3]CN)[sub 4][sup 2][sup +] complex: 1.99(1) and 3.12(1) [angstrom], respectively. No solvate molecules in the axial positions could however be seen by any of the technique used. The structure of the tetraaquacopper(I) ion has been assumed to be tetrahedral, and from a correlation between the difference in bond length between the copper(I) and copper(II) solvates and the disproportionationmore » constants of copper(I) in the solvent, the Cu-O bond distance is predicted to be approximately 0.14 [angstrom] longer than the equatorial Cu-O distances in the Jahn-Teller distorted hexaaquacopper(II) complex, thus about 2.13 [angstrom]. « less
Silicon Inverse‐Opal‐Based Macroporous Materials as Negative Electrodes for Lithium Ion Batteries

Several types of silicon‐based inverse‐opal films are synthesized, characterized by a range of experimental techniques, and studied in terms of electrochemical performance. Amorphous silicon inverse opals are fabricated via chemical vapor deposition. Galvanostatic cycling demonstrates that these materials possess high capacities and reasonable capacity retentions. Amorphous silicon inverse opals perform unsatisfactorily at high rates due to the low conductivity of silicon. The conductivity of silicon inverse opals can be improved by their crystallization. Nanocrystalline silicon inverse opals demonstrate much better rate capabilities but the capacities fade to zero after several cycles. Silicon–carbon composite inverse‐opal materials are synthesized by depositing a thin layer of carbon via pyrolysis of a sucrose‐based precursor onto the silicon inverse opals. The amount of carbon deposited proves to be insufficient to stabilize the structures and silicon–carbon composites demonstrate unsatisfactory electrochemical behavior. Carbon inverse opals are coated with amorphous silicon producing another type of macroporous composite. These electrodes demonstrate significant improvement both in capacity retentions and in rate capabilities. The inner carbon matrix not only increases the material conductivity but also results in lower silicon pulverization during cycling.
Uranium Sorption on Solid Aluminosilicate Phases under Caustic Conditions

Abstract: The formation of aluminosilicate scales in the High Level Waste Evaporators at the Savannah River Site led to curtailed operation and an expensive cleaning evolution due in part to the presence of enriched uranium in the scale. Therefore, the sorption behavior of uranium species and sodium aluminosilicate (NAS) solid phases in nitrate/nitrite-rich sodium aluminosilicate solutions were studied under well-defined conditions at 22°C and agitation rate of 400 rpm. The NAS solids comprised four well-characterized phases of amorphous, zeolite A, sodalite, and cancrinite. Pure, synthetic sodium diuranate (Na2U2O7) crystals were precipitated and used as the base/reference U-containing compound. The studies of the sorption behavior of U-containing species on NAS solid phases were conducted under conditions where no detectable dissolution, precipitation, or crystallographic phase transformation of the NAS adsorbent phases were observed over a 6h test period. The uranium sorption capacities were reached typically within 3h. The uranium capacities were measured 6.36 to 9.3mgUkg−1 NAS solid for the Zeolite A and cancrinite phase. The amorphous and sodalite phase had higher uranium loading that measured between 19 and 58mgUkg−l NAS solid.
Pressurized Pulverized Fuel Combustion in Different Concentrations of Oxygen and Carbon Dioxide

Theoretical and experimental studies showed that increasing gas pressure at constant gas composition most strongly increases the combustion rate of less reactive coals, which are difficult to burn completely in atmospheric pulverized fuel boilers. The effect of pressure increase is greatest near 0.1 MPa and less at higher pressures. The limit at which increase in pressure has an effect varies from coal to coal, depending on the particle size. With less reactive coals and small particles, the effect can be seen at pressures greater than 1 MPa. The relative effect of pressure increases when the gas oxygen content is low, improving the burnout in furnaces. The effect of pressure is small for large particles and reactive fuels. At high pressures the rates of homogeneous and heterogeneous reactions increase raising the maximum particle temperature; the higher temperature may increase the extent of devolatilization and further decrease the total combustion time. Combustion rate and the temperature of burning co.
Comparative study of ion, x-ray and neutron emission in a low energy plasma focus

In a low energy (2.3 kJ) Mather-type deuterium plasma focus, neutron and x-ray emission is investigated by time integrated and time resolved detectors. CR-39 nuclear track ion detectors are employed for measuring charged particle angular distribution. Correlation of charged particles with neutron and x-ray emission is also investigated. The neutron emission profile is found to be composed of two pulses, the intensity and anisotropy of which vary with the filling pressure. The charged particle flux is maximum with high fluence anisotropy for the pressure range 2.5-3.0 mbar which is also the optimum pressure for high neutron emission with low fluence anisotropy . The high neutron emission with low fluence anisotropy is attributed to the presence of trapped deuterons in an anomalous magnetic field. The relevant pressure range generates favourable conditions for plasma density and pinch filament diameter. X-ray emission is generally high at low pressure. For the pressure range of 2.5-4.0 mbar, the axial neutron detector registers a hard x-ray pulse, which may escape through a half inch thick Cu flange. These results suggest that at low pressures, the collapsing current sheath interacts with the anode end and causes intense low energy x-ray emission, but the neutron emission remains low. X-rays are dominantly Cu . In the narrow pressure regime 2.5-3.0 mbar, the current sheath forms a pinch filament leading to high neutron yield with low fluence anisotropy.
Boundary-induced electrophoresis of uncharged conducting particles: remote wall approximations

An initially uncharged ideally polarizable particle is freely suspended in an electrolyte solution in the vicinity of an uncharged dielectric wall. A uniform electric field is externally applied parallel to the wall, inflicting particle drift perpendicular to it. Assuming a thin Debye thickness, the electrokinetic flow is analysed for large particle–wall separations using reflection methods, thereby yielding an asymptotic approximation for the particle velocity. The leading-order correction term in that approximations stems from wall polarization.
Optimization of Spray Drying of an Innovative Functional Food: Fermented Mixed Juice of Carrot and Watermelon

This work deals with formulation and drying of a newly developed functional food. A watermelon and carrot juice mixture in the ratio 70:30 by volume was fermented at 37°C with Lactobacillus acidophilus to produce an innovative non-dairy-based food formulation with good flavor and high nutritional value. Viable count, pH, titrable acidity, protein content, and reducing sugar were measured during fermentation. The probiotic juice was spray dried at air temperature of 120 to 160°C and flow rate of 2.0 to 5.0 mL/min. Maltodextrin concentration of 10 to 15% by weight was used as an additive. Response surface methodology (RSM) was employed to optimize the drying process conditions. Physical properties (e.g., moisture content, density, porosity, and yield), biological properties (e.g., viability and lycopene and beta carotene content), and solubility data were examined as the response variables. Elevated temperatures and longer exposure times at lower feed rate reduced viability and lycopene and beta carotene content of the dried powder. Increased atomization pressure increased the cohesiveness but decreased flowability of the dried powder because the particle size was lowered. The probiotic powder was further analyzed using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC).
Combined bond polarization function basis sets for accurate ab initio calculation of the dissociation energies of AHn molecules (A=LI to F)

An alternative route toward developing basis sets for post‐Hartree‐Fock calculations, the hybrid bond polarization function method, is investigated. Two new basis sets, denoted 6‐31G(d, p)+ B and 6‐31 + G(d,p)+B, are defined for the first‐row hydrides. The dissociation energies of the first‐row hydride species in their respective ground states are computed using full fourth‐order Møller‐Plesset theory, and compared with results obtained with large polarized basis sets containing no bond functions. It is shown that results are competitive even with basis sets as large as 6‐311++G(3df,3pd), while computation times are reduced by a factor of 4 to 20. On empirical grounds, the basis set superposition error should be neglected entirely.
Growth of rice plants under red light with or without supplemental blue light

Abstract The effects of blue light supplementation to red light on growth, morphology and N utilization in rice plants (Oryza sativa L. cv. Sasanishiki and Nipponbare) were investigated. Plants were grown under two light quality treatments, red light alone (R) or red light supplemented with blue light (RB; red/blue-light photosynthetic photon flux density [PPFD] ratio was 4/1), at 380 mol m−2 s−1 PPFD. The biomass production of both cultivars grown under RB conditions was higher than that of plants grown under R conditions. This enhancement of biomass production was caused by an increase in the net assimilation rate (NAR). The higher NAR was associated with a higher leaf N content per leaf area at the whole-plant level, which was accompanied by higher contents of the key components of photosynthesis, including Rubisco and chlorophyll. In Sasanishiki, preferential biomass investment in leaf blades and expansion of wider and thinner leaves also contributed to the enhancement of biomass production. These morphological changes in the leaves were not observed in Nipponbare. Both the changes in physiological characteristics, including leaf photosynthesis, and the changes in morphological characteristics, including leaf development, contributed to the enhancement of biomass production under RB conditions, although the extent of these changes differed between the two cultivars.
Pre‐column liquid chromatographic determination of dipicolinic acid from bacterial endospores

A high performance liquid chromatographic (HPLC) method for fluorescence detection of dipicolinic acid (DPA), a unique component of bacterial endospores, was developed for rapid and highly sensitive quantification of endospores. DPA was pre‐column complexed to the lanthanide metal terbium (Tb3+). Surplus free Tb3+ and the Tb3+‐DPA complex were separated by reverse‐phase gradient chromatography and the fluorescence emission was read at 545 nm after exitation at 270 nm. The limits of quantification (LOQ) and detection (LOD) were 0.26 and 0.08 nM, respectively. The method was used to detect DPA extracted from Bacillus subtilis endospores, DPA extracted from B. subtilis endospores added to more complex substrates such as marine sediment and canned tuna and DPA extracted from indigenous endospores in a coastal marine sediment. Endospores represented 4% of the microbial community (bacterial cells + endospores) in active surface sediment from the Aarhus Bay.
The valence‐charge density of graphite

A full sphere of data extending to (sin θ/λ) = 1.2 A-1 and containing 1595 reflections was measured with small, natural, single crystals of graphite and Mo Kα radiation. With the structure assumed to be in space group P63/mmc, the valence-charge density of the two independent C atoms was represented by a finite multipole expansion containing products of single-exponential radial functions and tesseral harmonics. A full-matrix, least-squares refinement of the model charge was computed where populations of the multipole deformations, thermal parameters, scale, and extinction parameters were refined. The experimental data fit a model charge density containing highly directional build-ups of charge to 2 e A-3 between nearest neighbors in the basal plane. No structure was evident in the charge density between the basal planes. The refinable parameter, α, in the exponential radial function was 3.16 ± 0.05 bohr-1. The charge density and associated parameters are consistent with strong covalent bonding of sp2 character in the basal plane of graphite and minimal interactions between the layers.
International Journal of Food Engineering Quality of Wastewater of the Sudanese Fermentation Industry

The quality characteristics of wastewater of the Sudanese Fermentation Industry (ElHassaheissaGezira State) were investigated. The study indicated that wastewater contained higher amounts of nutrients. The percentage of protein of the separator waste and the main drain waste were found to be 0.5% and 0.7%, respectively. The molasses waste contained higher amounts of total solids (56.8 mg/l) while separator waste, filter waste and the main drain waste contained 0.4 mg/l, 0.4 mg/l and 0.24 mg/l, respectively. The molasses waste had a higher BOD (640 mg/l) and COD (4500 mg/l) values compared to the separator waste, filter waste and main drain waste which contained 250 mg/l, 450 mg/l and 148 mg/l BOD values, respectively. However, the COD values of separator waste, filter waste and main drain waste were 250 mg/l, 160 mg/l and 80 mg/l respectively. Different wastewater samples contained relatively high concentrations of macro-and micro-elements and mineral salts. The microbiological analysis indicates absence of staphylococci and coliform in most of the wastewater samples.
Effects of chloride fertilizers on yield and uptake of chloride, potassium and sodium by fodder beet (Beta vulgaris L.) in two New Zealand soils

summary The effects of applications of sodium chloride (NaCl) and potassium chloride (KCl) ranging from 0 to 720 kg Cl/ha on the yield and uptakes of chloride (Cl) potassium (K) and sodium (Na) by fodder beet were studied in field experiments at two sites in New Zealand. At 360 kg Cl/ha applied, both NaCl (590 kg/ha) and KC1 (758 kg/ha) increased significantly yields of fresh roots, dry roots and fresh sugar content of fodder beet over the minus-Cl plants. Compared with the sulphate anion, chloride application stimulated K uptake in tops and roots. Results indicated that in the beet crop, uptake of K is enhanced with the presence or addition of Cl (as NaCl) compared with SO4 (as NaSO4). In both soils, total (tops and roots) uptakes of K, Cl, and Na were significantly correlated with fresh roots, dry roots and fresh sugar content. Multiple regression analyses showed that total K uptake was the main nutritional factor which determined yields of fresh and dry roots in the Templeton soil, whilst in the Wakanui soil total Cl uptake and total K+total Cl uptakes determined fresh root and dry root yields, respectively. In both soils, high Cl uptake was required for increased sugar yields.
Chemical-induced allergy and autoimmunity

This thesis aims towards a better understanding of the mechanisms that lead to chemical-induced adverse immune effects. We focussed thereby on the initial induction stage of the immune reaction that consists of three major steps: (i) formation of neoantigen, (ii) processing and presentation of the neoantigen, and (iii) recognition of peptide-MHC-complex by the T cell. Chemical induced allergy or autoimmunity is often observed after administration of certain drugs or after contact with industrial or environmental chemicals. T cells play a central role in the development of drug-induced adverse immune reactions. A major difficulty in studying T-cell reactions to sensitizing chemicals is the fact that in most cases the ultimate neoantigen recognized by "drug-specific" T cells is unknown. As most T cells can only recognize peptides on MHC molecules, chemicals have to bind to a protein carrier in order to be recognized by T cells. Parts of this neoantigen are presented on MHC molecules on the surface of the APC and can be engaged by T cells. In order to bind to proteins, most chemicals have to be metabolized into protein-reactive intermediates, called haptens. Although the liver is the main organ for metabolic transformation, it does not play a major role in the induction of chemical induced adverse immune effects. In contrast, cells from the immune system itself, like neutrophils and monocytes have been shown to be involved in drug-metabolism prior to drug-induced adverse immune effects. In this thesis we have tried to elucidate some of the mechanisms involved in chemical induced adverse immune effects. Some of the steps possibly involved in the formation of neoantigens and subsequent T cell recognition are discussed. The hypothesis that extrahepatic metabolism plays an important role in the formation of neoantigen with the prohaptens procainamide and aniline could be substantiated, and the processing of protein adducts, presentation of neoantigens and subsequent recognition of either haptenated peptides or cryptic peptides by T cells was shown. Furthermore, this thesis elucidates some of the mechanisms involved in cross-sensitization and discusses the possible implications of T-cell cross-reactivity in chemical induced allergy and autoimmunity.
Nucleation and Growth of a Chromate Conversion Coating on Aluminum Alloy AA 2024-T3

The nucleation and growth of a chromate conversion coating on aluminum alloy AA 2024-T3 has been investigated by atomic force microscopy, scanning electron microscopy, and transmission electron microscopy techniques. Through the careful preparation of fresh, clean, and well-characterized alloy specimens through the novel use of an ultramicrotome, morphological changes associated with the initial stages of coating growth have been characterized and related to the microstructure of the alloy surface. Nonuniform growth of the conversion coating takes place locally at intermetallic particles and over the macroscopic alloy surface generally. For coating growth at intermetallic particles, coating development is influenced strongly by the size, shape and composition of the particles and the composition of the neighboring matrix regions. Coating nucleation and growth is observed as discrete nodules of film material formed at (Al, Cu) 6 Mn particles, or halos of film material surrounding Al 6 (Cu, Fe, Mn) and S-phase Al 2 CuMg particles. Film growth at S-phase Al 2 CuMg particles is supported by anodic dissolution of the particles, while that at Al 6 (Cu, Fe, Mn) particles is accompanied by localized dissolution of a copper-depleted matrix zone immediately adjacent to the particles. Concerning the macroscopic alloy surface, coating growth occurs preferentially along microstructural defects possibly introduced by rolling during alloy processing and along cellular and grain boundaries, which arc sites of alloying element segregation. Thus the unique and careful approaches adopted for specimen preparation have enabled the anodic and cathodic sites associated with coating nucleation and growth to he identified and related to the substrate microstructure. Based on the results of this study, a mechanism of growth of a chromate conversion coating on aluminum alloy AA 2024-T3 is proposed.