Miracle-dz/UniFAR-FTUs huggingface dataset:
Identification of electron and hole traps in lithium tetraborate (Li2B4O7) crystals: Oxygen vacancies and lithium vacancies

Electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) are used to identify and characterize electrons trapped by oxygen vacancies and holes trapped by lithium vacancies in lithium tetraborate (Li2B4O7) crystals. Our study includes a crystal with the natural abundances of B10 and B11 and a crystal highly enriched with B10. The as-grown crystals contain isolated oxygen vacancies, lithium vacancies, and copper impurities, all in nonparamagnetic charge states. During an irradiation at 77 K with 60 kV x-rays, doubly ionized oxygen vacancies trap electrons while singly ionized lithium vacancies and monovalent copper impurities trap holes. The vacancies return to their preirradiation charge states when the temperature of the sample is increased to approximately 90 K. Hyperfine interactions with B10 and B11 nuclei, observed between 13 and 40 K in the radiation-induced EPR and ENDOR spectra, provide models for the two vacancy-related defects. The electron trapped by an oxygen vacancy .
Changes in the Phenolic Content and Free Radical-scavenging Activity of Vacuum Packed Walnut Kernels during Storage

1 Yüzüncü Yıl University, Engineering and Architecture Faculty, Department of Food Engineering, 65080, Zeve Campus, Van, Turkey 2 Ankara University, Science Faculty, Department Of Chemistry, 06100, Tandoğan, Ankara, Turkey 3 Pamukkale University, Engineering Faculty, Department Of Food Engineering, 20020, Kınıklı Campus, Denizli, Turkey 4 Ankara University, Engineering Faculty, Department Of Food Engineering, 06110, Dışkapı, Ankara, Turkey
Development of Modified Wood Products Based on Furan Chemistry

The first processes for “furfurylation” of wood (wood modification with furfuryl alcohol) were developed several decades ago. Furfuryl alcohol is a renewable chemical since it is derived from furfural, produced from hydrolysed biomass waste. Over the last decade modernised processes for furfurylation of wood have been developed. These new processes are based on completely new catalytic systems and process additives. The properties of furfurylated wood depend on the retention of grafted/polymerised furfuryl alcohol (PFA) in the wood. At high modification levels (high retention of PFA) the enhancement of a wide variety of properties are achieved: an exceptional hardness increase, exceptional resistance to microbial decay and insect attack, high resistance to chemical degradation, increase in MOR and MOE, and high dimensional stability. At lower modification levels many property enhancements also occur, however to slightly lower extent. Notable are resistance to microbial decay and insect attack, increase in MOR and MOE, and relatively high dimensional stability. Two main processes for production of furfurylated wood have been developed for Kebony ASA (Former Wood Polymer Technology ASA) by the authors. Kebony TM for hardwood modification and VisorWood TM for soft wood modification, where the name reflects the colour of the material produced by the process. Commercial production according to the Kebony process has been running since October 2003, mainly for flooring. A small Kebony production plant is now in operation in Lithuania. A Kebony/VisorWood production plant was started during of 2003 in Porsgrunn, Norway. There are now planed for an expansion of this plant, and plans for a large Visorwood plant is ongoing. Further commercialisation of the technology will be done through licences issued by Kebony ASA.
The Suitability of Particle Models in Capturing Aggregate Structure and Polydispersity

This work presents the mathematical formulation of particle models commonly used in aerosol dynamics of nanoparticles. A detailed numerical study is conducted in order to understand under which conditions these models differ. The silica model of Shekar et al. (2012b) and silicon model of Menz et al. (2013) taken from the literature are analyzed using three different particle models, demonstrating that substantial errors can be incurred when using a particle model inappropriate for a particular modeling application. These errors can potentially be reflected in fitted parameters; should a parameter estimation procedure be employed with such models. It is concluded that the characteristic coagulation and sintering timescales define the conditions under which the use of a particular model is reasonable. Copyright 2013 American Association for Aerosol Research
Identification of Anti-Wood Rot Compounds in Teak (Tectona grandis L.f.) Sawdust Extract

Abstract The tropical hardwood sawdust of Tectona grandis L.f. from the wood processing industry was extracted and tested for anti-wood rot activity. Tectona grandis extract inhibited the brown rot fungi Gloeophyllum sepiarium, Gloeophyllum trabeum, Piptoporus betulinus and Serpula lacrymans, and the white rot fungi Bjerkandera adusta, Merulius tremellosus, and Phlebia brevispora. Centrifugal partition chromatography was used to separate these compounds using n-hexane-MeOH-H2O (50:47.5:2.5) as a solvent system. The compounds deoxylapachol, tectoquinone, 2-hydroxymethylanthraquinone, 3′-OH-deoxyisolapachol (2-[(1E)-3-hydroxy-3-methylbut-1-enyl]naphthoquinone), hemitectol (2,2-dimethyl-2H-benzo[h]chromen-6-ol), and tectol were isolated from Tectona grandis sawdust CHCl3-MeOH (1:1) extract. Deoxylapachol inhibited the brown rot fungi Gloeophyllum sepiarium CBS 353.74 and Gloeophyllum trabeum CBS 318.50 and the white rot fungi Merulius tremellosus CBS 280.73 and Phlebia brevispora CBS 509.92. Hemitectol together with tectol showed a high percentage of cellulase inhibition followed by 3′-OH-deoxyisolapachol and deoxylapachol.
Atomic Layer Deposition of High-k Dielectric Layers on Ge and III-V MOS Channels

Ge and III-V semiconductors are potential high performance channel materials for future CMOS devices. In this work, we have studied At. Layer Deposition (ALD) of high-k dielec. layers on Ge and GaAs substrates. We focus at the effect of the oxidant (H2O, O3, O2, O2 plasma) during gate stack formation. GeO2, obtained by Ge oxidn. in O2 or O3, is a promising passivation layer. The germanium oxide thickness can be scaled down below 1 nm, but such thin layers contain Ge in oxidn. states lower than 4+. Still, elec. results indicate that small amts. of Ge in oxidn. states lower than 4+ are not detrimental for device performance. Partial intermixing was obsd. for high-k dielec. and GeO2 or GaAsOx, suggesting possible correlations in the ALD growth mechanisms on Ge and GaAs substrates. [on SciFinder (R)]
Bioavailability of Fe(III) In Loess Sediments: An Important Source of Electron Acceptors

Fe-reducing micro-organisms can change the oxidation state of structural Fe in clay minerals. The interactions with complex clays and clay minerals in natural materials remain poorly understood, however. The objective of this study was to determine if Fe(III) in loess was available as an electron acceptor and to study subsequent mineralogical changes. The loess samples were collected from St. Louis (Peoria), Missouri, USA, and Huanxia (HX) and Yanchang (YCH), in the Shanxi Province of China. The total Fe concentrations for the three samples was 1.69, 2.76, and 3.29 wt. %, respectively, and Fe(III) content was 0.48, 0.69, and 1.27 wt. %, respectively. All unreduced loess sediments contained Fe (oxyhydr)oxides and phyllosilicates. Bioreduction experiments were performed using Shewanella putrefaciens CN32 with lactate as the sole electron donor and Fe(III) in loess as the sole electron acceptor with and without anthraquinone-2, 6-disulfonate (AQDS) as an electron shuttle. Experiments were performed in non-growth (bicarbonate buffer) and growth (M1) media. The unreduced and bioreduced solids were analyzed by X-ray diffraction, Mössbauer spectroscopy, diffuse reflectance spectroscopy, and scanning electron microscopy/energy dispersive spectroscopy. Despite many similarities among the three loess samples, the extent and rate of Fe(III) reduction varied significantly. In the presence of AQDS the extent of reduction in the non-growth experiment was 25% of total Fe(III) in HX, 34% in Peoria, and 38% in YCH. The extent of reduction in the growth experiment was 72% in HX, 94% in Peoria, and 65% in YCH. The extent of bioreduction was less in the absence of AQDS. Overall, AQDS and the M1 growth medium significantly enhanced the rate and extent of bioreduction. Fe(III) in (oxyhydr)oxides and phyllosilicates was bioreduced. Siderite was absent in control samples, but was identified in bioreduced samples. The present research suggests that Fe(III) in loess sediments is an important potential source of electron acceptors that could support microbial activity under favorable conditions.
TESTING DESIGN STIMULI FOR DESIGN-BY-ANALOGY ON A LARGE SET OF DESIGNERS

This paper presents evidence supporting the hypothesis that, for designers not specifically trained in designing-by-analogy, the sources of inspiration that share the same (sub-functions) and context of the target system lead to ideas having higher novelty and quality. The exploration of the design space gets positively affected as well. These evidence emerge after the statistical analysis of the results of an experiment that involved 84 graduate students in Mechanical Engineering, with typical competencies on engineering design, but without any specific skill on analogy-based idea generation.
Refractive index of water and steam as function of wavelength, temperature and density

Based on a comprehensive collection of data previously obtained by Thormahlen et al. on the experimental refractive index of water and steam from the 1870s to the present, a new formulation is presented for the range of 0.2 to 2.5 μm in wave‐length, −10 to +500 °C in temperature and 0 to 1045 kg m−3 in density. The Lorentz‐Lorentz function or molar refraction, a strong function of wavelength but only weakly dependent on density and temperature, is fitted to a selected set of accurate refractive index data. The NBS/NRC equation of state for water and steam, the new international standard, is used to convert the experimental pressures to density.The deviations of all experimental data from the formulation are shown. A detailed assessment of the accuracy of the formulation is presented. Although the formulation does not represent to within their accuracy the data from the best sets in the visible range for liquid water below the boiling point, we show that inconsistencies between data sets, and minor deficie.
Interaction of Two Micro-slot Flames: Heat Release Rate and Flame Shape

This paper studies the interaction between two identical micro-slot diffusion flames. Here, we define a micro-slot flame as a slot flame of which the slot width is less than about 1 mm. Because of its smallness, a micro-slot flame has a high heating density and can be used as a small heat source. However, the heat release rate of a single micro-slot flame is limited, and therefore, multiple micro-slot flames may be used to increase total heat release rate. As a first step, this paper considers a situation in which two micro-slot flames are used with certain burner spacing. When two diffusion flames are placed closely, flame shape changes from that of an isolated flame. Studying such flame shape change and resultant change in total heat release rate is the topic of this paper. Experiment is conducted and total heat release rate is measured by integrating CH* chemiluminescence recorded using a CCD camera and an optical filter of the wavelength of 430 nm. Two different burner materials, copper and glass, are tested to study the effect of heat loss to burners. An analytical model is applied to predict flame shape. In addition to the classical Burke-Schumann assumptions, two slot flames are modeled as line sources with zero width, enabling a simple analytical solution for the critical burner spacing at which two flames touch each other. The critical burner spacing is a key parameter that characterizes the interaction between two micro-slot flames. Computational fluid dynamics (CFD) simulations are then conducted to test the validity of the present theory. CFD results are favorably compared with the theoretical prediction.
Electrical breakdown of liquid helium

An interim report of the measurements on the electrical breakdown of liquid helium at steady voltages as a function of the electrode gap distance and the temperature is given. The influence of the rate of rise of voltage has also been studied as well as the damage of the electrodes by the formation of craters. Special attention has been paid to the purification of the helium, since small particles of solid air or dust, for example, have a strong influence on the results obtained.
APPARENT RECOVERY OF FERTILIZER N BY VEGETABLE CROPS

Apparent recoveries of fertilizer N by crops were studied as their treatment in simulation models is a serious problem. Multi-level N fertilizer experiments in which fertilizer was broadcast and incorporated in soil immediately before drilling were carried out on a range of vegetable crops on adjacent sites of the same field. At final harvest, apparent recovery always declined approximately linearly with the increase in fertilizer N even when less was applied than was needed for maximum uptake; this contrasts with the well-known constancy of apparent recovery of Gramineae (winter wheat and grass) over widely different rates. At the seedling stage (of vegetables), when N-uptakes were very small, N-uptake and invariably dry weight, unexpectedly increased with the increase in fertilizer N until very high levels were reached. A single simulation model, with species differences accounted for by variations in the value of only one coefficient, defined, at least qualitatively, all the various phenomena. It is ar.
On the use of AM1 and MNDO wave functions to compute accurate electrostatic charges

A new strategy to evaluate accurate electrostatic charges from semiempirical wave functions is reported. The rigorous quantum mechanical molecular electrostatic potentials computed from both MNDO and AM1 wave functions are fitted to the point‐charge molecular electrostatic potential to obtain the electrostatic charges. The reliability of this strategy is tested by comparing the semiempirical electrostatic charges for 21 molecules with the semiempirical Mulliken charges and with the ab initio STO‐3G and 6‐31G* electrostatic charges. The ability of the dipoles derived from the semiempirical electrostatic and Mulliken charges as well as from the SCF charge distributions to reproduce the ab initio 6‐31G* electrostatic dipoles and the gas phase experimental values is determined. The statistical analysis clearly point out the goodness of the semiempirical electrostatic charges, specially when the MNDO method is used. The excellent relationships found between the MNDO and 6‐31G* electrostatic charges permit to define a scaling factor which allows to accurately reproduce the 6‐31G* electrostatic charge distribution as well as the experimental dipoles from the semiempirical electrostatic charges.
Measurement of the electric charge on particulates forming Coulomb crystals in the sheath of a radiofrequency plasma

Monodisperse electrically charged particulates (9.4 mu m diameter) are trapped in the sheath of an argon RF parallel plate discharge. The particulates form Coulomb crystals consisting of horizontal hexagonal layers. A method for the determination of the charge on the particles is demonstrated that uses the response to a modulation of the electrode bias. Charges about three to five thousand elementary units are measured. The commonly applied orbital motion limited (OML) charging model leads to charges higher than the measured values. The strong coupling system is compared to the one component plasma (OCP model) and to a model with Yukawa potentials.
Two-dimensional nuclear magnetic resonance study of a hydrated porous medium: An application to white cement

Structure and dynamics of a hydrated white cement were investigated by the T1-weighted lineshape, two-dimensional (2D) exchange, and 2D separation of inhomogeneous and homogeneous lineshapes nuclear magnetic resonance (NMR) techniques. T1 weighting of the proton spectrum eliminates the strong bulk water signal from the pores so that the weaker spectrum of the solid cement matrix becomes observable. The proton spectrum of the solid cement fraction exhibits a characteristic Pake doublet shape and shows a close similarity to the powder spectra of pure calcium hydroxide and the crystalline water of gypsum. The 2D exchange NMR spectrum of white cement demonstrates the existence of slow chemical exchange processes of protons in the solid matrix on a sub-kHz frequency scale. This exchange is orders of magnitude slower than the exchange between the surface and bulk water. The 2D NMR separation of inhomogeneous and homogeneous lineshapes technique demonstrates that the absorption lines of a set white cement are in.
Synthesis of Well-Defined Homopolymer and Diblock Copolymer Grafted onto Silica Particles by Z-Supported RAFT Polymerization

Well-defined homopolymer and diblock copolymer were prepared by RAFT polymerization mediated by Z-supported chain transfer agent (CTA) onto silica particles. Silica-supported 3-(methoxycarbonylphenylmethylsulfanylthiocarbonylsulfanyl)propionic acid (Si-MPPA) was used to mediate RAFT polymerization of methyl acrylate, methyl methacrylate, butyl acrylate, and styrene to produce homopolymer grafted silica. The introduction of a free CTA such as MPPA and 2-(2-cyanopropyl) dithiobenzoate (CPDB) in solution during polymerization could significantly improve the control on molecular weight and polydispersity of grafted polymers, and the polymerization in the presence of CPDB was more controlled than that using MPPA. The resultant homopolymer grafted silica was utilized as a macro-CTA to mediate chain extension polymerization, and a series of diblock copolymer grafted silica hybrids were prepared. Aminolysis of the polymers allowed the recovery of the polymeric chains showing 100% chain extension, as illustrated b.
A simple collisional–radiative model for low-pressure argon discharges

A simple collisional–radiative model for low-pressure argon discharges is proposed. Using this model and the measured cross section data from recent literature, the relationship between the electron density and some emission line intensities is investigated, resulting in a semi-empirical formula relating the electron density and the emission intensity ratio of argon lines (from levels 3p and 4p). The electron density determined from this model is compared with that from a Langmuir probe in an inductively coupled argon plasma. The application and validity of this model in other kinds of low-pressure argon plasmas, such as capacitively coupled and helicon plasmas, or in discharges containing both argon and other gases are discussed.
Density minimum and liquid–liquid phase transition

We present a high-resolution computer simulation study of the equation of state of ST2 water, evaluating the liquid-state properties at 2718 state points, and precisely locating the liquid–liquid critical point (LLCP) occurring in this model. We are thereby able to reveal the interconnected set of density anomalies, spinodal instabilities and response function extrema that occur in the vicinity of an LLCP for the case of a realistic, off-lattice model of a liquid with local tetrahedral order. In particular, we unambiguously identify a density minimum in the liquid state, define its relationship to other anomalies, and show that it arises due to the approach of the liquid structure to a defect-free random tetrahedral network of hydrogen bonds.
Complex Dynamics in a PEM Fuel Cell

Oscillatory kinetics in a polymer electrolyte membrane fuel cell (PEMFC) was studied at different applied currents and fluxes in the anodic compartment. The system consisted of a Pt/C cathode fed with oxygen and a PtRu(1:1)/C anode fed with H2 mixed with 108 ppm of CO, and was operated at 30 C. Many different states including periodic and non-periodic series were observed as a function of the applied current (j) and the H2/CO flux. In general, aperiodic/chaotic states were favored at high currents and low flux. This allowed us to discuss the connection between the observed dynamics and the reaction mechanism.
Ferroelectric relaxor Ba(Ti,Ce)O3

The dielectric behaviour of Ba(Ti1−yCey)O3 solid solutions (y = 0–0.3) has been studied. A small amount of Ce doping (y = 0.02) has weak influence on the dielectric behaviour of Ba(Ti1−yCey)O3. With increasing Ce concentration, three phase transitions of pure BaTiO3 are pinched into one rounded dielectric peak with frequency dispersion, and the relaxation time follows the Vogel–Fulcher relation. The evolution from a normal ferroelectric to a ferroelectric relaxor is emphasized. High strains (S = ~ 0.1–0.19%) with a small hysteresis under ac fields are obtained in ferroelectric relaxors Ba(Ti1−yCey)O3. The physical mechanism of the relaxation process, the pinching effect of the phase transitions and their influence on the ferroelectric and electrostrictive behaviour are discussed.
Response of the sorption behavior of Cu, Cd, and Zn to different soil management

This study investigated the effect of different farming practices over long time periods on the sorption-desorption behavior of Cu, Cd, and Zn in soils. Various amendments in a long-term field experiment over 44 y altered the chemical and physical properties of the soil. Adsorption isotherms obtained from batch sorption experiments with Cu, Cd, and Zn were well described by Freundlich equations for adsorption and desorption. The data showed that Cu was adsorbed in high amounts, followed by Zn and Cd. In most treatments, Cd ions were more weakly sorbed than Cu or Zn. Generally, adsorption coefficients K F increased among the investigated farming practices in the following order: sewage sludge ≤ fallow < inorganic fertilizer without N ≈ green manure < peat < Ca(NO 3 ) 2 < animal manure < grassland/extensive pasture. The impact of different soil management on the sorption properties of agricultural soils for trace metals was quantified. Results demonstrated that the soil pH was the main factor controlling the behavior of heavy metals in soil altered through management. Furthermore, the constants K F and n of isotherms obtained from the experiments significantly correlated with the amount of solid and water-soluble organic carbon (WSOC) in the soils. Higher soil pH and higher contents of soil organic carbon led to higher adsorption. Carboxyl and carbonyl groups as well as WSOC significantly influenced the sorption behavior of heavy metals in soils with similar mineral soil constituents.
Structural phase transitions during high-energy ball milling of BaTiO3

Microstructural characterization of ball milled perovskite BaTiO3 powders has been done by the modeling of X-ray diffraction profiles. The study reveals that on size reduction, BaTiO3 powders undergo a continuous, displacive, and diffusionless dynamic phase transitions involving tetragonal (T), monoclinic (M), and orthorhombic (O) symmetry via the second-order type [T → (T + M) → (M + O) → O] when stimulated by a high-power pulse of pressure in a planetary mill. The order parameter, a phenomenological quantity to describe the general behavior of a system going through phase transitions has been estimated using spontaneous strain calculated from lattice parameters or physical distortions derived from atomic coordinates or both. At room temperature, BaTiO3 nanoparticle achieved an orthorhombic phase when a critical size (<15 nm) has been reached at later stage of milling (≥70 h). Raman's study reveals similar structural phase transitions sequence on size reduction and TEM study reveals the corresponding particle diameter.