Miracle-dz/UniFAR-FTUs huggingface dataset:
Liquid Crystalline Behaviour of Chitosan in Formic, Acetic, Monochloroacetic Acid Solutions

The objective of this work was to prepare polysaccharide-based gels exhibiting liquid crystalline properties. Such systems may be used in some optical or in biomedical applications, where biodegradability is required. Chitosan is a derivative of chitin, widely used in a series of medical applications. Due to its rigid structure, chitosan or its derivatives may show lyotropic mesophases in certain conditions. In this work, chitosan solutions were prepared by mixing completely the polysaccharide with different concentration of formic, acetic and monochloroacetic acids at room temperature. X-ray diffraction patterns of the gels did not show the existence of a crystalline structure. Finger-prints texture observed by polarised optical microscopy was attributed to a cholesteric liquid crystalline phase that usually develops in concentrated solutions. Values of the nematic chiral pitch (P) were determined in function of acid solution concentration. The critical concentrations (C*) to form a lyotropic liquid crystalline phase in formic, acetic and monochloroacetic acids were determined, and the obtained values were confronted with the expected critical concentration based on the Flory formalism. The critical concentration values were found to be dependent upon the acid used.
Usage des tablettes numériques pour favoriser le passage à l’écrit de collégiens présentant un trouble spécifique du langage écrit

La presente etude s’interesse aux eleves dyslexiques-dysorthographiques de 6eme/5eme scolarises en ULISTAP (Unite Localisee pour l’Inclusion Scolaire –Trouble des APprentissages) et vise a determiner dans quelle mesure l’utilisation de tablettes tactiles favorise leur autonomie lors des temps de scolarisation en classe ordinaire et tout particulierement pour le passage a l’ecrit. Les resultats obtenus soulignent l’interet de la tablette, aisement prise en main par les eleves, elle facilite l’organisation materielle, accelere la prise de notes et ameliore la qualite graphique et syntaxique des ecrits produits. Cependant, d’autres aspects comme le correcteur orthographique ou l’ecriture intuitive complexifient l'activite et empechent certains eleves de focaliser leur attention sur le contenu du cours et les informations centrales a memoriser.
Influence of reductant and germanium concentration on the growth and stress development of germanium nanocrystals in silicon oxide matrix

Germanium (Ge) nanocrystals have been synthesized by annealing co-sputtered SiO2–Ge samples in N2 or forming gas (90% N2+10% H2) at temperatures ranging from 700 to 1000 °C. We concluded that the annealing ambient, temperature and Ge concentration have a significant influence on the formation and evolution of the nanocrystals. We showed that a careful selective etching of the annealed samples in hydrofluoric acid solution enabled the embedded Ge nanocrystals to be liberated from the SiO2 matrix. From the Raman results of the as-grown and the liberated nanocrystals, we established that the nanocrystals generally experienced compressive stress in the oxide matrix and the evolution of these stress states was intimately linked to the distribution, density, size and quality of the Ge nanocrystals.
Detailed analysis of the atrial natriuretic factor receptor hormone-binding domain crystal structure.

The X-ray crystal structure of the dimerized atrial natriuretic factor (ANF) receptor hormone-binding domain has provided a first structural view of this anti-hypertensive receptor. The structure reveals a surprising evolutionary link to the periplasmic-binding protein fold family. Furthermore, the presence of a chloride ion in the membrane distal domain and the presence of a second putative effector pocket suggests that the extracellular domain of this receptor is allosterically regulated. The scope of this article is to extensively review the data published on this receptor and to correlate it with the hormone-binding domain structure. In addition, a more detailed description is provided of the important features of this structure including the different binding sites for the ANF hormone, chloride ion, putative effector pocket, glycosylation sites, and dimer interface.Key words: crystal structure, periplasmic-binding protein fold, guanylyl cyclase, hormone receptor.
Self‐assembly of pH‐responsive acrylate latex particles at emulsion droplets interface

The self-assembly of pH-responsive poly (methyl methacrylate-co-acrylic acid) latex particles at emulsion droplet interfaces was achieved. Raising pH increases the hydrophilicity of the latex particles in situ and the latex particle acts as an efficient particulate emulsifier self-assembling at emulsion droplet interface at around pH 10–11 but exhibits no emulsifier activity at higher pH. This effect can be reversibly induced simply by varying the aqueous phase pH and thus the latex emulsifier can be reassembled. The effect factors, including the aqueous phase pH, the surface carboxyl content, ζ-Potential of the latex particles and oil phase solvent have been investigated. Using monomer as oil phase, the latex particles could stabilize emulsion droplets during polymerization and cage-like polymer microspheres with hollow core/porous shell structure were obtained after polymerization. The mechanism of the latex particles self-assembly was discussed. The morphologies of emulsion and microspheres were characterized by optical microscopy, scanning electron microscopy, and transmission electron microscopy. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
A MODEL FOR PREDICTING THE REDISTRIBUTION OF SALTS APPLIED TO FALLOW SOILS AFTER EXCESS RAINFALL OR EVAPORATION

Summary A model is described for predicting the movement of soluble unadsorbed anions (such as nitrate or chloride) in fallow freely drained soil under field conditions. The model includes routines for estimating both the downward leaching of salts (after excess rainfall or irrigation) and the capillary movement of anions to the soil surface (after evaporation). The profile is divided into layers each of which is characterized by a maximum and minimum water content (the field capacity and evaporation limit respectively). Daily amounts of rainfall and evaporation are applied to the surface and the redistribution of water and salts is calculated (on a layer-to-layer basis) from the initial water and salt contents of each layer by adding or subtracting water to or from the moisture content until the stated maximum or minimum value is reached. Salt transfer is calculated from the amount af water movement on a proportional basis. The predictions of the model have been tested using field data for the redistribution of nitrate and chloride in a sandy loam soil. Good agreement was obtained for chloride, but the results for nitrate showed some deviations probably due to the effects of denitrification.
Anharmonic Potential Constants and Their Dependence upon Bond Length

Empirical study of cubic and quartic vibrational force constants for diatomic molecules shows them to be approximately exponential functions of internuclear distance. A family of curves is obtained, determined by the location of the bonded atoms in rows of the periodic table. Displacements between successive curves correspond closely to those in Badger's rule for quadratic force constants (for which the parameters are redetermined to accord with all data now available). Constants for excited electronic and ionic states appear on practically the same curves as those for the ground states. Predictions based on the diatomic correlations agree with the available cubic constants for bond stretching in polyatomic molecules, regardless of the type of bonding involved. Some implications of these regularities are discussed.
Polymer Network Formed in Liquid Crystals: Polymer-Network-Induced Birefringence in Liquid Crystals

A monomer with reactive double bonds was mixed with a liquid crystal and polymerized under UV irradiation in various phases of the liquid crystal. The polymer networks formed are found to be anisotropic and fiber-like, if the monomer is polymerized in an oriented liquid crystal state. The orientational order of the polymer network is shown to depend on that of the liquid crystal. After polymerization, the polymer network, in turn, is found to affect the orientation of the liquid crystal significantly. It induces birefringence in nematics at temperatures just above the nematic-isotropic phase transition.
Accessing the kinetics of the supra-tauc range via relaxation dispersion NMR spectroscopy

Nuclear Magnetic Resonance spectroscopy (NMR) is capable of attaining dynamic information of motions over a broad range of time scales under physiological relevant conditions while maintaining atomic resolution. Of the NMR accessible time scales structural information from the supra-tauc range, a four orders of magnitude time window between the overall rotational correlation time to the relaxation dispersion limit of 40 microseconds has been accessed only via structural information derived from residual dipolar couplings. Previously for ubiquitin, motion from the supra-tauc range could be linked to its molecular recognition process. Here, kinetics displayed within this regime are measured for the protein ubiquitin and can be attributed to the lifetime of interconversion between conformers for ubiquitin free in solution. This is demonstrated by super-cooled relaxation dispersion (RD) type experiments. It is also shown that the accessible time window for RD type experiments can be increased with the use of a cryogenically cooled probehead. For 15N, 13C, and 1H nuclei motions as fast as 25, 10, and 4 microseconds are now possible. This technique was further applied to measure RD for a variety of nuclei across ubiquitin. The extended time resolution for 15N nuclei was also applied to enhance the accuracy of kinetics measured by other RD experiments. Additionally, preliminary work is presented on the detection of conformational sampling events during a binding interaction between two proteins. As it becomes increasingly transparent that the dynamics of a system can govern its function, the approaches outlined here can help in validating, testing, or reinforcing our understanding of the complex and dynamic nature of systems of biological interest.
Thermal expansion of the lowest-temperature phase of benzene: hexafluorobenzene

Neutron diffraction measurements of the anisotropic thermal expansion of the molecular complex C6D6∶ C6F6 have been used to investigate the intermolecular forces and vibrational properties in the solid low-temperature phase (IV). Assuming a simple first-order approximation to the thermal expansion an intermolecular bond strength and average frequency have been derived which are in agreement with other estimates, and consistent with a Lennard-Jones type of potential. The thermal expansion is approximately isotropic below 150 K, and becomes slightly anisotropic as a precursor to the phase transition at 205 K. The nature of the anisotropy suggests that the phase transition is to some extent associated with the onset of rotational motion of the aromatic molecules about their six-fold axes. This conclusion is consistent with previous quasielastic neutron scattering observations.
Bilbao Crystallographic Server : Useful Databases and Tools for Phase-Transition Studies

Bilbao Crystallographic Server is a web site with crystallographic programs and databases available on-line. The programs give access to general information related to space groups (generators, general positions, Wyckoff positions, irreducible representations), group-subgroup or group-supergroup pairs of space groups, and/or results on specific crystal structures. The utility of the programs is illustrated by treating phase-transition problems related to structural pseudosymmetry.
Removal of Methyl tert-Butyl Ether from Contaminated Water by Macroreticular Resin

Removal of methyl tert-butyl ether (MTBE), a widely used gasoline additive, by adsorption was investigated. Commercially available macroreticular resin was employed in the adsorption process. Batch experiments were conducted to determine the equilibrium MTBE adsorption capacity which, in turn, was utilized to identify the adsorption isotherms. Column tests were made to examine the performances of continuous adsorption operations under conditions of different inlet MTBE concentrations, feed flow rates, and temperatures. A theoretical model based on the general logistic function was adopted and tested for describing the MTBE breakthrough behaviors of the adsorption resin column. The identified breakthrough model significantly facilitates practical design of the MTBE adsorption system. Regeneration of exhausted adsorption resin was also preliminarily investigated to determine its effectiveness for repeated use. The resin adsorption process was found to be efficient in the removal MTBE from contaminated water.
Effect of deep placement of controlled release nitrogen fertilizer (coated urea) on growth, yield, and nitrogen fixation of soybean plants

Abstract The objective of these studies is to increase the productivity of soybean [Glycine max (L.) Merr. cv. Enrei] with good quality by the application of controlled release nitrogen fertilizers. Soybean was grown in an upland field converted from a drained paddy field in Niigata. The fertilizer treatments were as follows: (a) control, conventional basal dressing of ammonium sulfate (16 kg N/ha); (b) deep placement, deep placement of coated urea, 100 day type (100 kg N/ha) with basal dressing of ammonium sulfate (16 kg N/ha); (c) top dressing, top dressing of coated urea, 70 day type (100 kg N/ha) just before the flowering stage with basal dressing of ammonium sulfate (16 kg N/ha). We employed the following methods and materials: “15N-labeled fertilizers,” to estimate the amount of N derived from fertilizers; “N-balance method” using the nodulating and non-nodulating isogenic line cv. T202 and T201, to estimate the amount of fixed N2 by root nodules; “relative ureide method” to determine the relative c.
Thermal plasma properties for Ar–Al, Ar–Fe and Ar–Cu mixtures used in welding plasmas processes: I. Net emission coefficients at atmospheric pressure

This article is devoted to the calculation of the net emission coefficient (NEC) of Ar–Al, Ar–Fe and Ar–Cu mixtures at atmospheric pressure for arc welding processes. The results are given in data tables for temperatures between 3 kK and 30 kK, for five plasma thicknesses (0, 0.5, 1, 2, 5 mm) and ten concentrations of metallic vapours (pure gas, 0.01%, 0.1%, 1%, 5%, 10%, 25%, 50%, 75% and pure metal vapours in mass proportions). The results are in good agreement with most of the works published on the subject for such mixtures. They highlight the influence of three parameters on the radiation of the plasma: the NEC is directly related to temperature and inversely related to plasma radius and is highly sensitive to the presence of metal vapours. Finally, numerical data are supplied in tables in order to develop accurate computational modelling of welding arc and to estimate both qualitatively and quantitatively the influence of each metallic vapour on the size and on the shape of the weld pool.
Muscle Compliance and the Longitudinal Transmission of Mechanical Impulses

The time required for a mechanical impulse to propagate from one end to the other was measured directly in frog sartorius muscles and in fiber bundles from the semitendinosus muscle. When the fibers were fully activated, the transmission velocity was 170 mm/ms. In resting fibers the transmission time was three to four times greater than in activated fibers. Control experiments indicated that the transmission time across the tendons was negligible. A muscle compliance of 55–80 Å per half sarcomere was estimated from these data. The "measurement time" of the method was calculated to be about 15 µs. This relatively short measurement time makes the method potentially useful for detecting changes in cross-bridge compliance.
OXIDATION OF m-XYLENE IN A JSR: EXPERIMENTAL STUDY AND DETAILED CHEMICAL KINETIC MODELING

Abstract New experimental results were obtained for the oxidation of meta-xylene studied in a jet-stirred reactor at atmospheric pressure in dilute conditions over the temperature range 900–1400 K, and variable equivalence ratio (0.5 ≤ ϕ ≤ 1.5). They consisted of concentration profiles of the reactants, stable intermediates and final products, measured by sonic probe sampling followed by on-line GC-MS analyses and off-line GC-TCD-FID and GC-MS analyses. The oxidation of meta-xylene in these conditions was modeled using a detailed chemical kinetic reaction mechanism (189 species and 1359 reactions, most of them reversible) deriving from a previous scheme proposed for the ignition, oxidation, and combustion of simple aromatics (benzene, toluene, styrene, n-propyl-benzene, and para-xylene). Sensitivity analyses and reaction path analyses, based on rates of reaction, were used to interpret the results. This study showed the reactivity of m-xylene is quite similar to that of p-xylene under the present conditions: m-xylene reacts slightly slower than p-xylene.
Ab Initio Crystal Structure Predictions for Flexible Hydrogen-Bonded Molecules

Crystal structure predictions for glycol and glycerol are reported. A series of increasingly accurate energy calculations is applied, and the final predictions are based solely on ab initio derived energies. A recently developed transferable ab initio potential is used for intermolecular interactions, augmented with ab initio derived conformational energies. The experimental structure of glycol was predicted with a low energy, 1.1 kJ/mol above the global minimum. For glycerol the experimental structure corresponded to the global minimum. This latter result provides a proposal for the positions of the hydrogen atoms in the crystal structure of glycerol. A three-dimensional hydrogen-bonded network is formed which consists only of intermolecular hydrogen bonds. Together with previous work, the ab initio intermolecular potential has now been applied to predict the crystal structures of six different compounds. The energy difference between the observed crystal structure and the global energy minimum varied fr.
Solid state crystal-to-crystal transformation from a monomeric structure to 1-D coordination polymers on anion exchange,

Yellow crystals of monomeric structure [Zn(bpdh)2(H2O)4](NO3)2·2bpdh (1) convert on heating at ca. 160 °C under grinding and mixing with KSCN or NaN3 to white and orange 1D coordination polymers, [Zn(µ-bpdh)2(NCS)2]n (2) and [Zn(µ-bpdh)2(N3)2]n (3), respectively. In the crystal lattice, the coordination number of Zn(II) does not change with the removal of four water molecules and forms a new type of Zn⋯Nbpdh and Zn⋯NNCS/N3.
Synthesis of α–Al_2O_3 platelets using sodium sulfate flux

When powder mixtures of {Al_2(SO_4)_3 + Na_2SO_4}or {γ–Al_2O_3 [obtained by heating Al_2(SO_4)_3 at 900 °C for 3 h] + Na_2SO_4} were heated in an alumina crucible at 1100 °C for 1 h, α–Al_2O_3 platelets were formed. The powder mixture of {Al_2(SO_4)_3 + 2Na_2SO_4} yielded aggregations of platelets that were less than 5 μm in size. The size of the aggregations increased in proportion to the amount of Na_2SO_4, and aggregations of 120 μm were obtained using a mixture of {Al_2(SO_4)_3 + 6Na_2SO_4}. The powder mixture of {γ–Al_2O_3 + 2Na_2SO_4 yielded hexagonal platelets having an average diameter of 3.7 μm and an average thickness of 0.3 μm. In addition to aggregation size, the size of the hexagonal platelets also increased in proportion to the amount of Na_2SO_4, and platelets having an average diameter of 5 μm were obtained using a mixture of {γ–Al_2O_3 + 6Na_2SO_4}.
FOLIAR SPRAYS OF PHOTOSYNTHETIC BACTERIA IMPROVE THE GROWTH AND ANTI-OXIDATIVE CAPABILITY ON CHINESE DWARF CHERRY SEEDLINGS

Recently, there has been increasing attempts for photosynthetic bacteria (PSB) as foliar fertilizer in China. The biomass, net photosynthetic rate (Pn), maximal photochemical efficiency of PS II(Fv/Fm) and antioxidant isoenzymes metabolism were examined in Chinese dwarf cherry (Prunus humilis Bunge) seedlings with or without exogenous PSB application in this study. PSB sprays resulted in a significant accumulation of fresh weight and leaf area of Chinese dwarf cherry plants, accompanying with a marked increase of Pn. However, Fv/Fm had negligible changes. The exogenous PSB also induced the activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX), and a general increase of their isoenzymes activities. The increased level was the most significant in chloroplasts [such as Cu/Zn-SOD, Fe-SOD and stroma APX (sAPX)]. Our results demonstrated that PSB played a favorable role in growth and photosynthesis and improved the antioxidative capability in plants.
Review and Perspective of Hf-based High-k Gate Dielectrics on Silicon

HfO2 has been recently highlighted as the most promising high-k dielectrics for the next-generation CMOS device applications due to its relatively high dielectric constant and superior thermodynamic stability from calculated Gibbs free reaction with Si. However, the high permeability to oxygen, the low crystallization temperature and the formation of the low-k interfacial layer during high temperature processing causes equivalent oxide thickness scaling and reliability concerns. Therefore, novel Hf-based high-k gate dielectrics should be studied to meet the requirements of the future advanced CMOS devices. This article provides a comprehensive view of the state-of-the-art research activities in advanced Hf-based high-k gate dielectrics, including their preparation, characterization, and potential applications in CMOS device. We begin with a survey of the requirements of high-k oxides, and then various methods developed for generating Hf-based high-k gate dielectrics. After that, more attention has been paid to the detailed discussion of on the latest development of novel Hf-based high-k gate dielectrics which have the potential for integration into a full CMOS process. Finally, we conclude this review with the perspectives and outlook on the future developments in this area. This review explores the possible influences of research breakthroughs of Hf-based gate dielectrics on the current and future applications for nano-MOSFET devices.
Comportamento de variáveis climáticas em sistemas de ventilação mínima para produção de pintos de corte

During the creation process of poultry, the initial or heating phase, is characterized as the most delicate period due to physiological immaturity of the birds. Thus, environmental factors stand out to infer, directly, in the growth, on the performance and maintenance of life of these animals. Based on these considerations, the aim of this study was to study the effect of three different systems of minimum ventilation (positive pressure, negative and natural) on environmental variables (air temperature, relative humidity and wind velocity) of broiler sheds during the heating phase. According to results obtained, it was verified that the heating system used was inadequate to maintain the air temperature and relative humidity within the standards deemed appropriate, thus exposing the birds to periods of heat stress by cold. In contrast, there were negative influences regarding ventilation rates applied to the two ventilation systems positive and negative. Wind velocity also remained at levels considered non-stressful for young chickens.