Miracle-dz/UniFAR-FTUs huggingface dataset:
Heat Conductivity of Polyatomic and Polar Gases and Gas Mixtures

A theory is presented which can be used for the practical calculation of the heat conductivity of polyatomic and polar gases and gas mixtures. For pure gases, the results are based on the Wang Chang—Uhlenbeck equations and involve no approximations, provided that a suitable definition of an internal diffusion coefficient is employed. This is compared with the known results for a gas of rough spheres, and found to hold to all orders of approximation. Approximations enter for real gases only in obtaining numerical estimates of internal diffusion coefficients and relaxation times. The result is essentially the same as that of Mason and Monchick. For mixtures, the results are based on the formal kinetic theory recently obtained by Monchick, Yun, and Mason. A brief digression on sound absorption and dispersion in mixtures is made in order to identify the cross relaxation times in the formulas. Two assumptions are required for mixtures to obtain usable formulas: neglect of ``complex collisions,'' and no correla.
Thread-safe and efficient data representations in dynamically-typed languages / submitted by Benoit Daloze, M.Sc.

We are in the multi-core era. Dynamically-typed languages are in widespread use, but their support for multithreading still lags behind. Specifically, their runtime systems either lack support for parallelism completely or they have many drawbacks, such as not scaling, having a significant overhead for single-threaded applications and exposing implementation-level races to the user. Runtime systems use sophisticated techniques to efficiently represent the dynamic objects and versatile collections present in dynamically-typed languages. One of the major reasons for not supporting well parallelism is these techniques are often unsafe in multi-threaded environments. In this thesis, we present a solution for efficient and thread-safe shared-memory parallelism in dynamically-typed language runtimes. First, we design a new efficient and thread-safe object model for dynamic languages, only requiring synchronization when writing to objects shared between multiple threads. Accesses to objects reachable by only a single thread remain unsynchronized and maintain single-threaded performance. Then, we devise a thread-safe and scalable design for collections in dynamic languages, which we apply to array-like and dictionary-like collections. We use multiple levels of synchronization to optimize for the usage pattern of each collection instance. Collections operations are unsynchronized until the collection becomes reachable by multiple threads. For array accesses within bounds, we use a new mechanism for global synchronization, avoiding overhead for this usage pattern. For the general case, we introduce a new lock that provides scalability for both read and write accesses, while supporting the versatile operations that dynamic languages provide and retaining the sophisticated techniques for representing collections efficiently in memory. We evaluate our work in TruffleRuby, a state of the art high-performance implementation of the Ruby programming language. We show that our thread-safe objects and collections do not cause any overhead when they are reachable by only a single thread. Our experiments show that our approach scales linearly for object, array and dictionary accesses, achieves the same scalability as statically-typed languages for classic parallel algorithms, and scales better than other Ruby implementations on Ruby workloads.
The role of mineral and organic components in phenanthrene and dibenzofuran sorption by soil

Improved predictions of sorption of hydrophobic organic compounds (HOCs) in soil require a better knowledge of the relative contribution of inorganic and organic soil constituents to the sorption process. In this paper, sorption of a three‐ring polycyclic aromatic hydrocarbon (phenanthrene) and a three‐ring heterocyclic–aromatic compound (dibenzofuran) by six agricultural soils, their clay‐size fractions, and a series of single, binary, and ternary model sorbents was evaluated to elucidate the relative role of soil mineral and organic components in the retention of these two model HOCs. The sorption coefficients for phenanthrene and dibenzofuran on purified soil organic materials (Kd = 821–9080 litre kg−1) were two orders of magnitude greater than those measured on mineral model sorbents (Kd = 0–114 litre kg−1). This, along with the strong correlation between sorption and the organic C content of the soil clay fractions (r = 0.99, P < 0.01), indicated a primary role of soil organic matter in the retention of both compounds. However, weak relationships between phenanthrene and dibenzofuran sorption coefficients and the organic C content of the bulk soils and variability of Koc values among soils, clay fractions, and model sorbents (1340–21020 litre kg−1 C for phenanthrene and 1685–7620 litre kg−1 C for dibenzofuran) showed that sorption was not predictable exclusively from the organic C content of the materials. Organic matter heterogeneity and domain blockage arising from organic matter–clay interactions and associated pH shifts were identified as the most likely causes of the different organic C‐normalized sorption capacities of the soils. A direct contribution from minerals to the sorption of phenanthrene and dibenzofuran by the soils studied was likely to be small. Our results suggested that suitable descriptors for the extent of organic matter–mineral interactions would help to improve current Koc‐based sorption predictions and subsequently the assessment of risk associated with the presence of HOCs in soil.
The modification of graphene with alcohols and its use in shape memory polyurethane composites

Graphene prepared by the thermal reduction of graphite oxide was modified by reactions with methanol or 1-butanol using aqueous HBF4 solution as a catalyst. Results showed that the reaction created hydroxyl groups on the graphene and at the same time reduced the number of defects. Gravimetry, thermogravimetry, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy showed that the alcohols had reacted with epoxide groups on graphene. Raman spectroscopy showed that the defects in the graphene were repaired through other accompanying reactions. The reinforcing effect of graphene, observed in the tensile properties and the shape memory behavior of graphene/polyurethane composites, was increased when the graphene was modified with methanol. However, decreases in density and glass transition temperature were evident for the composites made with alcohol-modified graphene. These results show that the newly created hydroxyl groups on graphene produce effective covalent bonds with the polyurethane chains of the matrix; however, the increased number of bonds restricts the rearrangement of the matrix molecules for dense packing. The covalent bonds between graphene and polyurethane chains enhanced shape recoverability and reduced the hysteresis brought about by repeated thermomechanical cycles. Copyright © 2012 Society of Chemical Industry
Wear of the artificial hip joint material under lubrication

A study of wear properties of hip-replacement materials, namely high-nitrogen stainless-steel femoral heads and ultra-high molecular weight polyethylene (UHMWPE), was conducted in a non-conforming apparatus using various liquid lubricants. The liquids used were normal saline solution, sodium azide solution, pure ethanol, aqueous hyaluronic acid and aqueous hyaluronic acid/cholesterol and cholesterol palmitate liquid crystal lubricant. Saline solution proved to be unsuitable as a lubricant while sodium azide that was used as a bactericide provided some evidence of mixed lubrication. A bactericide was included to overcome degradation. The aqueous hyaluronic acid exhibited cushion form lubrication as evidenced by retention of the original polymer surface features within the wear indent. Cholesterol addition showed little improvement on the wear properties but massively increased the bacterial activity. Again, inclusion of a bactericide was necessary. Liquid crystal lubricant significantly reduced wear and the atomic force microscope (AFM) showed that the liquid crystal formed protective layers on the counter face surfaces. The sub-surface of the polymer possessed plastic creep under load but low adhesive wear was present. There also was an absence of sub-micron polymer debris. It was concluded that a dramatic reduction in wear could be achieved by incorporation of liquid crystal lubricant in hip-replacement elements. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Towards very large scale DFT electronic structure calculations

DFT electronic structure calculations have proven their usefulness for a wide range of systems. However, the computational demands prohibit their application to systems containing more than a few hundred of atoms. Since many systems of practical interest, e.g. biomolecules and nanostructures, exceed by far the hundred atom regime, it is crucial to develop new algorithms which reduce the computational cost. In this context, the following methods are presented: Grid-free DFT implementation of local and gradient-corrected XC functionals, electrostatic decoupling of periodic systems, general and efficient algorithms for obtaining maximally-localized Wannier functions and polarized atomic orbitals for linear scaling methods. Die vorliegende Dissertation stellt eine Reihe von neuen Algorithmen zur DFT Ab-initio Simulation groser Systeme vor. Folgende Methoden werden behandelt: Analytische Berechnung des DFT Austausch-Korrelations-Anteils, DFT Simulation isolierter Systeme mit ebenen Wellen, Berechnung von Wannier-Funktionen und linear-skalierende DFT Methoden.
Demonstration of Germacrene A as an Intermediate in 5-Epi-aristolochene Synthase Catalysis

Sesquiterpene synthases are a family of enzymes that catalyze farnesyl pyrophosphate (FPP) cyclization via alternative pathways to produce a variety of cyclic sesquiterpene products. Catalysis by several of these enzymes, including tobacco 5-epi-aristolochene synthase (TEAS), has been proposed to include the formation of germacrene A as a stable intermediate. Neither germacrene A nor any other intermediate is released from sesquiterpene synthase active sites during normal catalysis. Evidence to support the intermediacy of germacrene A has been derived from investigations of aristolochene synthases from Aspergillus terreus and Penicillium roquefortii (Cane, D. E. Chem. Rev. 1990, 90, 1089−1103 and references therein. Cane, D. E.; Bryant, C. J. Am. Chem. Soc. 1994, 116, 12063−12064. Cane, D. E.; Tsantrizos, Y. S. J. Am. Chem. Soc. 1996, 118, 10037−10040). However, until the present investigations of TEAS, formation of this postulated intermediate has never been directly demonstrated. TEAS catalyzes the cycl.
Electrochemical deposition of macroporous platinum,palladium and cobalt films using polystyrene latex sphere templates

Highly ordered macroporous films of platinum, palladium and cobalt with regular arrays of spherical pores with diameters of 0.40, 0.70 or 1 μm are prepared by electrochemical deposition into the interstitial spaces of a template formed by polystyrene latex spheres self-assembled on gold electrodes; after deposition of platinum, palladium or cobalt, the polystyrene spheres are fully removed by washing in toluene to leave a highly periodic, hexagonal close packed, interconnected network of monodisperse spherical pores within the metal film, the size of which is determined by the diameter of the polystyrene latex particles used to prepare the template.
Synthesis of pyrrolopyridines (azaindoles)

Improved, convenient, and reliable routes for the synthesis of 4-, 5-, 6-, and 7-azaindole, 7-methyl-4-azaindole, 7-methyl-6-azaindole, and the hitherto unreported 7-amino-4-azaindole are described. The syntheses have been accomplished either by significant modifications to established procedures or by new methods which afford the compounds in improved yields.
Perturbations of the Dushman Reaction with Piroxicam: Experimental and Model Calculations

Perturbation of the BrayLiebhafsky non-oscillating subsystem (mixture of KIO3 and H2SO4), i.e., Dushman reaction (DR), by piroxicam (PX), was observed in an open reactor, i.e., in the continuously fed well-stirred tank reactor (CSTR). Monitoring the response of DR to perturbations by different concentrations of PX allows developing a simple procedure for quantitative determination of this analyte in both bulk drug and pharmaceutical preparation (injection). A tentative perturbation mechanism of PX action on the DR matrix, based on a kinetic scheme that was suggested by Agreda et al., is proposed. The PX reactivity in DR has been generally related to the reaction of PX with hypoiodous acid (HIO) present in the matrix.
Electrodeposition of α‐ and β‐cobalt hydroxide thin films via dilute nitrate solution reduction

α‐ and β‐cobalt hydroxyde thin films were synthesized by cathodic electrodeposition on transparent conductive oxide (TCO) substrates, at 60 °C and 95 °C, respectively, using a very low concentration of Co(NO3)2 and an alkali nitrate supporting electrolyte. Localized cathodic electrochemical generation of hydroxyl species via the reduction of nitrate precursors led to the formation of well crystallized nanostructured films. Scanning Electron Microscopy and X‐ray diffraction confirmed the films were composed of vertically oriented nanoparticle platelets with the c‐axis parallel to the substrate surface, and free of turbostratic disorder. UV/Vis spectra and thermal gravimetric analyses (TGA) indicated variation between the cobalt structures. Films deposited at 60 °C yielded a hydrotalcite‐like compound namely an “hydroxyl‐deficient” [Co(OH)2–x (H2O)x ]x + with NO3– intercalated anion along with water molecules in the interlayer region. Those deposited at 95 °C yielded the brucite β‐Co(OH)2. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonionic Amphiphilic Bilayer Structures under Shear

The effect of shear on the lamellar phase of amphiphilic systems has been widely studied in a variety of amphiphilic systems as a function of shear rate. In this investigation, we fixed the shear rate and performed temperature scan experiments on a two-component (C10E3−water) system. We observed a sequence of phases, from the low to high temperature range: multilamellar vesicle to planar lamellar to sponge phase. The shear-induced multilamellar vesicle (MLV) phase exhibited the most interesting behavior and is the main focus of the present study. Small-angle neutron and light scattering techniques were used to elucidate the microstructure, to determine the bilayer orientation, and to characterize the size of these structures. The interlamellar spacing was observed to be the same in the lamellar as in the MLV phase, and the MLV phase exhibited symmetrical scattering in the neutral and flow directions, indicating that the layers in the vesicles are spherically shaped at the selected shear rate (γ = 100 s-.
Studies of incorporation and stability of model flavouring compounds on black tea.

Flavoured teas have a good potential and popularity in the export market. In the present studies, 4 model flavouring compounds, i.e. citronellol, phenylethylalcohol, citral and bergamot oil, were incorporated in black tea and their storage characteristics were studied at 3 temp. conditions, 5 degree C, ambient and 37 degree C, using laminated Al foil, metal can and metallized polyester as packaging materials for a period of 90 days. These were evaluated by instrumental (GC/UV) and sensory methods. Considerable flavour loss was observed in metallized polyester package, at 37 degree C and during the 1st month of storage. The 1st 3 flavoured teas showed a shelf life of 90 days while the bergamot flavoured tea had a shelf life of only 60 days. Highly significant linear correlation was established between the instrumental and sensory values.
Two‐Dimensional Nb‐Based M4C3 Solid Solutions (MXenes)

Herein, two new two-dimensional Nb4C3-based solid solutions (MXenes), (Nb-0.8,Ti-0.2)(4)C3Tx and (Nb-0.8,Zr-0.2)(4)C3Tx (where T is a surface termination) were synthesizedas confirmed by X-ray diff .
Controlling Hydrogen Embrittlement in Precharged Ultrahigh-Strength Steels

Abstract An Fe-13Co-11Ni-3Cr-1Mo-0.2C steel alloy, processed for ultrahigh-strength and fracture toughness, exhibits three distinct hydrogen trap states in a complex precipitation-hardened martensitic microstructure and is susceptible to severe hydrogen embrittlement (HE) at threshold stress intensity levels as low as 20 MPa√m. The causes of HE susceptibility include very high crack-tip tensile stresses and a reservoir of diffusible hydrogen that is trapped reversibly with a binding energy, Eb, of 11.5±0.5 kJ/mol at (Fe,Cr,Mo)2C precipitates. This reversibly trapped hydrogen repartitions to interstitial sites proximate to the highly stressed crack tip and, subsequently, may retrap at martensitic lath interfaces to produce substantial local hydrogen concentrations and transgranular embrittlement. These results are pertinent to the control of HE in this modern ultrahigh-strength steel with a cadmium-plated coating and codeposited hydrogen (H). Thermal desorption spectroscopy demonstrates that 190°C baking r.
Carbon nanopillar laterally grown with electron beam-induced chemical vapor deposition

We found that the lateral growth of a carbon nanopillar with electron beam-induced chemical vapor deposition (EB-CVD) was mainly dominated by forward scattering of the electron beam. The minimum diameter of the carbon nanopillar was reduced to 5 nm. In contrast, vertical growth with EB-CVD produced thicker pillars ∼50 nm in diameter, with a shape that reflected forward scattering of the primary electrons. Graphitization of the amorphous carbon nanopillars was also demonstrated by annealing, in which nanoiron particle traces were graphitized.
Electrochemical investigations on the performance of newly synthesized azomethine polyester on rebar corrosion

Novel azomethine‐based polyester is synthesized and the structure of the products is confirmed by 1H NMR, FT‐IR, and XRD. The as synthesized polymer is employed as inhibitor against the corrosion of rebar in artificially simulated concrete pore solution with chloride contamination (blank) by means of Tafel polarization and electrochemical impedance measurements. First time in literature, azomethine polyester is employed as inhibitor for rebar corrosion. Polarization studies exhibited the maximum inhibition efficiency of 98% at 1000 ppm concentration. Electrochemical studies revealed the mixed‐type nature of the inhibitors. The adsorption behavior of as synthesized polymeric inhibitor obeys Langmuir adsorption model. Mechanisms reveal the entire molecule is expected to adsorb on to the metal surface with near flat orientation and tend to arrange themselves parallel to each other covering the entire metal surface, hence, preventing the ingress of aggressive species to the metal surface. Further, SEM and atomic force microscope have proven the presence of adsorptive layer on the rebar under the simulated atmosphere.
Dielectric constant of a highly polarizable atomic fluid: the clausius–mossotti versus the onsager relation

The relation between the dielectric constant and the particle polarizability for a polarizable liquid composed of Lennard-Jones particles carrying a saturable induced dipole is studied by computer simulations. It is shown that the widely accepted Clausius–Mossotti relation is only valid for low polarizabilities and fails for high polarizabilities. The results can be fitted accurately by an Onsager-like relation using an effective particle radius measured in the simulations which is larger than the equivalent hard-sphere radius defined conventionally. Furthermore, the orientational ordering transition found at high polarizabilities is shown to be of anti-ferroelectric type.
Investigation into the Mechanism(s) which Permit the High-Rate, Degradation of PAHS and Related Petroleum Hydrocarbons in Sequencing Batch Reactors by Attached Cells in a Controlled Mixed Bacterial Community.

Investication into the Mechanism(S) Which Permit The High-rate , Degradation of Pahs and Related Patroleum Hydrocarbons in Sequencing Batch Reactors by Attached Calls in A Controlled Mixed Bacterial Commurity، للحصول على النص الكامل يرجى زيارة مكتبة الحسين بن طلال في جامعة اليرموك او زيارة موقعها الالكتروني
Synthesis of monodisperse styrene/methyl methacrylate/acrylic acid latex using surfactant‐free emulsion copolymerization in air

Monodisperse styrene/methyl methacrylate/acrylic acid (St/MMA/AA) copolymer microspheres have been prepared with surfactant-free emulsion polymerization in air. The presence of oxygen in the system not only caused an induction period but also decreased the average particle size (D p ). However increasing AA concentration ([AA]) gave a reduction in the induction period. The FTIR and NMR analysis of the latex copolymer confirmed that the correlation of the copolymer compositions with the feed compositions was much better at the lower [AA] than at the higher levels. The AA contents of the copolymers obtained in air were much lower than those of the copolymers obtained under N 2 protection. Decreasing [AA] led to decrease in the copolymer molecular weight and broadening of the molecular weight distribution, but the particle size distribution (δ/D p ) was unaffected. In addition, the average particle diameter (D p ) was proportional to [AA] -0.255 , and increasing comonomers feed content caused linear increase of D p , and a monodisperse sample with final solids contents up to 34.2 wt % was obtained.
Attachment of Streptavidin to β‐Cyclodextrin Molecular Printboards via Orthogonal Host–Guest and Protein–Ligand Interactions

Streptavidin (SAv) is attached to β-cyclodextrin (β-CD) self-assembled monolayers (SAMs) via orthogonal host-guest and SAv-biotin interactions. The orthogonal linkers consist of a biotin functionality for binding to SAv and adamantyl functionalities for host-guest interactions at β-CD SAMs. SAv complexed to excess monovalent linker in solution and then attached to a β-CD SAM could be removed by rinsing with a 10 mM β-CD solution. When SAv was attached to the β-CD SAM via the divalent linker, it was impossible to remove SAv from the surface by the same rinsing procedure. This is interpreted by assuming that two SAv binding pockets are oriented towards the β-CD SAM resulting in (labile) divalent and (stable) tetravalent β-CD-adamantyl interactions for the mono- and divalent linkers, respectively. This was confirmed by experiments at varying β-CD concentrations. When the [linker]/[SAv] ratio is reduced, a clear trend in the divalent-linker case is seen: the less linker the more protein could be removed from the surface. It is proven that the orthogonality of the binding motifs and the stability of the divalent linker at the -CD SAM allows the stepwise assembly of the complex at the β-CD SAM by first adsorbing the linker, followed by SAv. This stepwise assembly allows the controlled heterofunctionalization of surface-immobilized SAv.