Miracle-dz/UniFAR-FTUs huggingface dataset:
Interrelations of T1 and diffusion of water in acute cerebral ischemia of the rat

Interrelation of T1 and diffusion of water was studied in rat models of acute global and focal cerebral ischemia. Cortical T1, as quantified with an inversion recovery method, increased by 4–7% within a few minutes of global ischemia at 4.7 and 9.4 T, but a significantly smaller change was detected at 1.5 T. The initial T1 change occurred within seconds of cardiac arrest, much earlier than the extensive diffusion drop after 1–2 min. Thus, the initial increase in T1 upon acute cerebral ischemia is directly caused by cessation of blood flow. In transient middle cerebral artery occlusion (MCAO), prolonged T1 relaxation was detected within 10 min, with a subsequent increase during the course of ischemia. Spin density did not change during the first hour, showing that T1 increase was not caused by net accumulation of water. Interestingly, partial recovery of T1 upon release of MCAO, occurring independent of long‐term tissue outcome, was observed only in concert with diffusion recovery. Magn Reson Med 44:833–839, 2000. © 2000 Wiley‐Liss, Inc.
Advanced Oxidation Processes for Wastewater Treatment: Formation of Hydroxyl Radical and Application

Advanced oxidation processes (AOPs), defined as those technologies that utilize the hydroxyl radical (·OH) for oxidation, have received increasing attention in the research and development of wastewater treatment technologies in the last decades. These processes have been applied successfully for the removal or degradation of toxic pollutants or used as pretreatment to convert recalcitrant pollutants into biodegradable compounds that can then be treated by conventional biological methods. The efficacy of AOPs depends on the generation of reactive free radicals, the most important of which is the hydroxyl radical (·OH). The authors summarize the formation reactions of ·OH and the mechanisms of pollutants degradation. They cover six types of advanced oxidation processes, including radiation, photolysis and photocatalysis, sonolysis, electrochemical oxidation technologies, Fenton-based reactions, and ozone-based processes. Controversial issues in pollutants degradation mechanism were discussed. They review the application of these processes for removal of different kinds of toxic pollutants from wastewater, including aromatic compounds, dyes, pharmaceutical compounds, and pesticides, with emphasis on the parameters assessed, removal effectiveness, and the degradation mechanisms of pollutants. The authors discuss issues associated with practical wastewater treatment and offer suggestions for the direction for future researches.
Surface stability and electronic structure of hydrogen- and fluorine-terminated diamond surfaces: A first principles investigation

The effect of fluorine termination on the stability and bonding structure of diamond (111) surfaces were studied using first-principles calculations and compared with hydrogen termination by creating mixed F- and H-containing diamond surfaces. Surface F atoms, similar to H, formed sp^3-type bonding with C atoms, which resulted in a more stable 1 × 1 configuration. The surface phase diagram built showed that the F-terminated surface was more stable in a larger-phase space than H termination, because of the formation of strong ionic C–F bonds and the development of attractive forces between F atoms, resulting in close packing of large F atoms. Hence, the F-terminated diamond surface was more chemically inert. A large repulsive force was required to bring two F-terminated surfaces together, because of the negative charge on F atoms, resulting in reduced adhesion tendency between two F-terminated diamond surfaces compared with H-terminated surfaces.
Low field mobility and thermopower in one‐dimensional electron gas

A scattering theory of one‐dimensional electron gas formed in a narrow channel GaAs‐AlGaAs high electron mobility transistor has been developed. The mobility values for the different scattering mechanisms have been computed and their variation with temperature has been presented. The various scattering processes include acoustic phonon scattering for both deformation potential and piezoelectric scattering mechanisms, impurity scattering, and surface roughness scattering at lower temperatures and polar optic phonon scattering at higher temperatures. The effect of dynamic screening has also been included. Finally, the temperature variation of thermopower for different 1D electron concentrations has been shown and attempts have been made to interpret the results obtained.
Tie-Decay Networks in Continuous Time and Eigenvector-Based Centralities

Network theory is a useful framework for studying interconnected systems of interacting entities. Many networked systems evolve continuously in time, but most existing methods for the analysis of time-dependent networks rely on discrete or discretized time. In this paper, we propose an approach for studying networks that evolve in continuous time by distinguishing between interactions, which we model as discrete contacts, and ties, which encode the strengths of relationships over time. To illustrate our tie-decay network formalism, we adapt the well-known PageRank centrality score to our tie-decay framework in a mathematically tractable and computationally efficient way. We apply this framework to a synthetic example and then use it to study a network of retweets during the 2012 National Health Service controversy in the United Kingdom. Our work also provides guidance for similar generalizations of other tools from network theory to continuous-time networks with tie decay, including for applications to streaming data.
Über die Photooxidation von Polyäthylenglykolterephthalat‐Fasern

Der phoooxidative Abbau von Polyathylenglykolterephthalat-Fasern erfolgt radikalisch uber Peroxygenierungsreaktione. Die Glykolkomponente wird in 1- und 2-Stellung oxidiert, zudem entsteht noch Acetaldehyd. Als Oxidationsprodukte der Terephthalsaure wurden Mono- und 2,5-Dihydroxyterephthalsaure isoliert, die auch fur die Fluoreszenz in belichtetem Material verantwortlich sind. The photooxidative degradation of poly(ethyleneglycol terephthalate) fibres in initiated by the formation of free radicals and peroxidation reactions. These produce partial and mutual oxidation products from the glycol component of the polymer in addition to acetaldehyde. During this process the terephthalate residues undergo hydroxylation to form mono- and 2.5-dihydroxyterephthalic acid. Such residues cause a special fluorescence characteristic for light damaged polyester fibres.
Pólipos endometriais: aspectos clínicos, epidemiológicos e pesquisa de polimorfismos

PURPOSE: to evaluate the clinical and epidemiological risk factors for endometrial cancer in postmenopausal women with endometrial polyps, as well as the genetic polymorphism of the progesterone receptor (PROGINS). METHODS: a case-control study was designed with 160 postmenopausal women with endometrial polyps, compared to a normal Control Group of 400 postmenopausal women. The genotyping of PROGINS polymorphism was determined by the polymerase chain reaction. Clinical and epidemiological data were compared between benign endometrial polyps and 118 of the control subjects. Variables were also compared with regard to benign and malignant endometrial polyps. RESULTS: comparison of the epidemiological variables between groups showed a significant difference for age, ethnicity, time since menopause, parity, tamoxifen use, hypertension and breast cancer, all of them more prevalent in the polyp group. After adjustment for age, statistical significance remained only for parity (OR=1.1), hypertension (OR=2.2) and breast cancer (OR=14.4). There were six cases of malignant polyps (3.7%). The frequency of bleeding was 23.4% for benign polyps and 100% for malignant polyps, with large polyps being detected in 54.6% of the benign cases and in 100 of the malignnat ones. The frequency of arterial hypertension was 54.5% for benign polyps and 83.3% for the malignant ones. The frequency of PROGINS T1/T1, T1/T2 and T2/T2 polymorphism was 79.9%, 19.5% and 0.6%, respectively, for the polyp group, and 78.8%, 20.8% and 0.5% for the Control Group. CONCLUSIONS: elderly age, hypertension, and breast cancer were significantly associated with endometrial polyps. The presence of PROGINS polymorphism was not significantly associated with endometrial polyps. The incidence of malignant polyps was low and strongly associated with bleeding, large-sized polyp and arterial hypertension.
Mass spectrometry as en ecological tool for in situ measurement of dissolved gases in sediment systems

Abstract The use of membrane-inlet quadrupole mass spectrometry, as a method for quantitative monitoring of dissolved gases in natural or semi-natural environments, is described. Its advantages over other methods lie in the fact that it provides an accurate, sensitive means for non-invasive, continuous analysis of several dissolved gases simultaneously. The potential of mass spectrometry as an ecological tool is illustrated by representative results from measurements made on undisturbed and experimentally amended estuarine and fresh-water sediments. Dissolved gas profiles from the surface to a depth of 10 cm in the estuarine sediment showed that the dissolved oxygen decreased gradually until at 10 cm it was undetectable ( x was also detected; quantitation of carbon dioxide necessitates a correction for the contribution of NO x . Manipulation of conditions (gas phase, nitrogen and carbon sources) permitted ecological modelling.
Raman study of a deuterated iron hydroxycarbonate to assess long‐term corrosion mechanisms in anoxic soils

In several contexts such as cultural heritage, oil and gas or nuclear waste disposal, the long-term corrosion mechanisms of iron in anoxic soils are studied. For this purpose, corrosion layers formed on ferrous archaeological artefacts from the site of Glinet (16th century, Normandy, France) were characterised. The main phases identified are siderite (FeCO3), chukanovite (iron hydroxycarbonate: Fe2(OH)2CO3 and magnetite (Fe3O4). In order to provide reliable Raman references for further studies on carbonated systems, the iron hydroxycarbonate (chukanovite) was synthesised on iron discs. The corrosion mechanisms were investigated by re-corroding the archaeological samples in a deuterated solution. Raman characterisation on cross sections inside the layer revealed the presence of deuterated chukanovite, allowing the deuterium tracing of the spreading of the corrosion. A set of chukanovite samples was synthesised with various D/H ratios. Using these reference data, the proportion of deuterated chukanovite in re-corroded artefacts was evaluated, and the corrosion rate was estimated as less than 1.6 µm/year. Copyright © 2010 John Wiley & Sons, Ltd.
Measurement of the Rotational Diffusion Coefficient of Lysozyme by Depolarized Light Scattering: Configuration of Lysozyme in Solution

We have determined the rotational diffusion coefficient (DR) of lysozyme from the spectrum of the depolarized light scattered by this protein. The sample was illuminated by a single‐frequency He–Ne laser and the spectrum of the depolarized scattered light was analyzed using a high‐resolution spherical Fabry–Perot interferometer. We have determined D20,wR to be (16.7 ± 0.8) × 106/sec at 15% protein concentration. We have, in addition, measured the translational diffusion coefficient (DT) of lysozyme by employing the now‐familiar techniques of optical mixing spectroscopy to observe the spectrum of the polarized light scattered by the protein. We find D20,wT to be (10.6 ± 0.1) × 10−7 cm2/sec, independent of protein concentration between 1% and 15%. Our results for DR and DT, combined with Perrin's expressions for the rotational and translational diffusion coefficients of ellipsoids, indicate that lysozyme in solution is hydrodynamically equivalent to a prolate ellipsoid of revolution with major and minor axe.
EXTENSION OF THE SHELF‐LIFE OF BURFI BY PACKAGING

Burfi an Indian milk-based sweet, is susceptible to microbial spoilage that restricts its shelf life to 10 days. Large-scale marketability of burfi and its export potential requires longer shelf life. Therefore, our aim was maximizing shelf life by packaging means. Studies were carried out on burfi in different packaging materials under different atmospheres – normal packing,vacuum packing and use of a free-oxygen absorber – at 65% RH/27C. Normal packing even in barrier film did not effectively control microbial spoilage. Vacuum packing, although it retarded microbial growth, adversely affected texture and sensory quality. A free-oxygen absorber coupled with high-barrier materials like metallized films/foil laminates offered more than 45 days shelf life. Stored samples could be grouped by principal component analysis. The major sensory attributes contributing to grouping were color, firmness, chewiness, creamy and rancid notes. Sensory firmness and chewiness were found to have good correlation with instrumentally measured texture values.
Importance and evolution of phenolic compounds in olive during growth and maturation

Mise en evidence de 2 groupes parmi 11 varietes : les varietes a petits fruits ont une forte teneur en oleuropeine et une faible teneur en verbacoside, les varietes a gros fruits ont des caracteristiques inverses. La maturation puis l'apparition d'anthocyanes se traduisent par des variations des phenols
Influence of the Structure and Orientation of the Parent Phase on the Hysteresis of Single-Crystal Shape Memory Alloys

The results of high-resolution electron microscopy, calorimetry and tension-compression tests on the Cu-Zn-Al single-crystals, of calorimetry on the Mn-Cu, NiTi single-crystal and on the NiTi polycrystals are presented. The features of the pseudo-plastic (ferroelastic) hysteresis by the deformation of the single-crystals in the martensitic state are investigated in detail. The similarity of ferroelastic and ferromagnetic hysteresis, the strongly orientation dependence of the ferroelastic hysteresis and its independence on the temperature are shown experimentally, which are well known peculiarities of the ferroelastic hysteresis. The dissipated energy during a one cycle of the ferroelastic deformation has parabolic dependence on the strain with an proportionality coefficient which is determined as an effective modulus of the martensitic polydomain. The hysteresis of the thermal-induced, stress-free transformation of all samples is also investigated. Two equilibrium lines bracketing the permanent hysteresis inside the major hysteresis loop are found during the partial cycling. The dissipated energy involves two terms: the one, describing the permanent hysteresis, depends linear on the martensite phase fraction and the other, parabolic. The influence of the transformation type, polycristallinity and scanning rate on the thermal hysteresis are discussed.
Photoanodic properties of sol-gel-derived Fe2O3 thin films containing dispersed gold and silver particles

α-Fe2O3 films containing dispersed Au and Ag particles 5−20 nm in size were prepared on nesa silica glass substrates by the sol−gel method, using solutions of a mole ratio Fe(NO3)3·9H2O: (HAuCl4·4H2O or AgNO3):CH3COCH2COCH3:CH3OCH2CH2OH = 1:0.06:2:20 as the coating solution. The anodic photocurrent−potential characteristics and the action spectra were investigated in a three-electrode cell employing the film electrode as the working electrode. When the film electrode was illuminated with intense white light, the embedded metal particles did not affect the photoanodic properties of the electrode significantly. When the film electrode was illuminated with weak white light or weak monochromatic light, the metal particles, especially Au particles, enhanced the anodic photocurrent; the Au particles embedded in the electrode enhanced the quantum efficiency, IPCE, by about 8 times at a wavelength of 400 nm. Deposition of Au particles just on the surface of the Fe2O3 film also increased the photoanodic current, s.
Second harmonic generation measurements at high pressures on powder samples

Abstract This article reviews the most recent results concerning second harmonic generation (SHG) experiments of non-phase matchable and phase matchable powder samples at high pressures and explains the pressure dependence of the intensity of the SHG signal by correlating it to the ratio between the average coherence length and the average particle size. The examples discussed here include pressure-induced structural changes in quartz, ZnO, ice VII and KIO3. It is shown that the second harmonic generation technique is a unique tool for the detection of pressure-induced structural phase transitions. It is laboratory based and allows fast measurements. It is complementary to X-ray diffraction and provides additional information about the presence of an inversion center for unknown or controversially discussed structures at high pressure.
Diluted Magnetic Semiconductors

Diluted magnetic semiconductors (DMSs), i.e. semiconducting crystals whose lattice is made up in part of substitutional magnetic ions (e.g. Cd/sub 1-x/Mn/sub x/Te, Hg/sub 1-x/Fe/sub x/Se, Zn/sub 1-x/Co/sub x/S), are reviewed. The focus is on materials of the type A/sub 1-x//sup II/ Mn/sub x/B/sup VI/, which are the most thoroughly understood. However, the similarities and differences between these materials and the A/sub 1-x//sup II/Fe/sub x/B/sup VI/ and A/sub 1-//sup II/Co/sub x/B/sup VI/ systems are discussed wherever information on the latter system is available. The band structure of the materials, which determines their basic semiconducting properties, is examined. Special attention is given to exchange interactions between the magnetic ions themselves (the d-d interaction) and the interaction between the magnetic ions and band electrons (the sp-d interaction). Magnetic phenomena in DMS alloys are considered. Special attention is given to the physics of layered structures, such as quantum wells and superlattices, involving DMS materials. The prospects of device applications made possible by the properties of DMS alloys are assessed. >
Electrical and Reliability Characteristics of Ultrathin Gate Oxide Prepared by Oxidation in D 2O

In this letter, we present a novel gate oxidation process using D2O (deuterium oxide) as an oxidizing gas. The electrical and reliability characteristics of ultrathin gate oxide grown in D2O ambient have been investigated. Compared with a control oxide grown in H2O, a oxide grown in D2O exhibits a significant reduction of charge trapping and interface state generation. Based on a secondary ion mass spectroscopy (SIMS) analysis, we found a deuterium rich-layer at the Si/SiO2 interface. The improvement of electrical and reliability characteristics can be explained by the deuterium incorporation at the Si/SiO2 interface.
Silver speciation in wastewater effluent, surface waters, and pore waters

Silver, inorganic sulfide, and thiol compounds were measured in municipal wastewater effluent, receiving waters, and pore waters from an anoxic lake sediment in order to predict silver speciation in these systems. We found submicromolar concentrations of inorganic sulfide even in fully oxic surface water. This inorganic sulfide is likely to exist in the form of colloidal metal sulfides, which have been shown to be stable under oxidizing conditions for periods of several hours. Inorganic sulfide in both the wastewater effluent and receiving waters was found to be 200 to 300 times in excess of silver concentrations, whereas inorganic sulfide in the pore waters was 1,000 to 15,000 times in excess of silver concentrations. With sulfide in excess of silver, we predict silver sulfide complexes to dominate silver speciation. Thiols were present at low nanomolar levels in pore waters but were not detectable (<1 nM) in wastewater effluent or receiving waters. Thiols do not appear to be important to silver speciation in these freshwater systems. Partitioning of silver into particulate (>0.45 μm), colloidal (10 kDa, 0.45 μm), and dissolved (<10 kDa) size fractions showed that a significant proportion of silver is in the colloidal (30–35%) and dissolved phases (15–20%). Dissolved phase concentrations were relatively constant in the treatment plant effluent and receiving waters, suggesting that silver in the <10‐kDa size fraction is strongly complexed by ligands that are not significantly affected by aggregation or sorption processes.
The influence of compressive stress on the magnetic flux density in the three-phase induction motor core model

The magnetic properties are very sensitive to stress acting on practical constructed cores. However the influence has been not yet fully investigated for real cores, because the estimation of the distribution of stress is very difficult. In this paper, the local properties in the three-phase induction motor model core under compressive stress have been measured to investigate its influence in detail. The result shows that the compressive stress will cause slight enlargement of the rotational iron losses.
Variation of Thermodynamic Parameters in the Adduct Formation of β-Diketonato Chelates with 1, 10-Phenanthroline across the Lanthanoid Series

The enthalpy change in the adduct formation of tris[1-(2-thienyl)-4,4,4-trifluoro-1,3-butanedionato]lanthanoids (LnA3) with 1,10-phenanthroline (phen) as well as the formation constant of the adduct has been determined in chloroform across the lanthanoid series at 298 K by calorimetric titration and solvent-extraction techniques. The enthalpy change in the first adduct formation changes remarkably from light lanthanoids (endothermic) to heavy ones (exothermic), while the entropy change decreases largely from the middle to the heavy lanthanoids along with a small change from light to the middle of the series. Such a trend has been explained on the basis of the difference in the dehydration from lanthanoid(III) chelates and in the strength of the new bonding of chelates formed between tris(β-diketonato) lanthanoid(III) and phen across the lanthanoid series.
Geospatial analysis of meteorological drought impact on Southern Africa biomes

ABSTRACT Within Southern African biomes, droughts are recurrent with devastating impacts on ecological, economic, and human wellbeing. In this context, understanding the drought impact on vegetation is of extreme importance. However, information on drought impact on natural vegetation at the biome level is scanty and remains poorly understood. Most studies of drought impact on vegetation have largely focussed on crops. The few existing studies on natural vegetation are based on experiments and field measurements at individual tree level which are not representative of biomes. In this study, we mapped the spatial extent and severity of drought using the Standardized Precipitation Evapotranspiration Index (SPEI) and then quantified the drought impact on Southern African biomes using the Vegetation Condition Index (VCI) for the period 1998 to 2017. To compare drought impact across the biomes, we computed the percentage area of the biome with seasonal VCI <30. The drought trend for each biome was computed for each pixel using a linear regression model in R software using the seasonal VCI images from 1998 to 2017. Our result showed that extreme drought impact on vegetation was mainly confined to the southwestern biomes (i.e. the Nama karoo and desert biomes) with most drought occurring during the first half of the season. We also observed an increasing trend of VCI (1998 to 2017) across all biomes and this increasing VCI trend might be explained by woody encroachment which is prevalent in the Savannah and Grassland biomes. The results of this study provide baseline information on drought hotspots.