Miracle-dz/UniFAR-FTUs huggingface dataset:
The C-O Stretching Infrared Band as a Probe of Hydrogen Bonding in Ethanol–Water and Methanol–Water Mixtures

ABSTRACT Infrared spectra of the ethanol–water and methanol–water mixtures in the mole fraction range of 0.1 to 0.9 were recorded in the attenuated reflection (ATR) mode. Traditionally, the hydrogen bonding of water with other molecules has been studied by investigation of the OH stretching band frequencies and intensities of water. However, in the case of alcohol–water mixtures, this procedure presents a problem due to the complete overlap of the hydroxyl absorptions from the alcohol and water. In the present study, we have adopted an alternative approach of understanding the ethanol–water and methanol–water hydrogen bonds through the analysis of the C-O stretching band. The intrinsic high intensity of the C-O band and nearly complete absence of its overlap with the water bands make it a good candidate for the study of hydrogen bonding interactions in alcohol–water mixtures. The integrated areas of the C-O stretching band versus mole fractions were plotted for both mixtures. In the case of methanol–water mixtures, the C-O stretching band area plot was linear, whereas such plot for the ethanol–water mixtures had two distinct slopes that switched at the 0.5 mole fraction. The C-O band plot areas were used to explain the molecular associations in the mixtures studied.
The stuffed framework structure of BaGa2O4

Abstract Crystals of barium monogallate were obtained by growth from a stoichiometric melt at 1350°C. The hexagonal crystals belong to space group P 6 3 , a =18.6403(7) A and c =8.6801(2) A, V =2611.9(2) A 3 , Z =24, D calc. =5.20 g cm −3 . The structure was solved by Patterson techniques using a single crystal diffraction data set. Merohedral twinning of the crystal (twin element 2 [110] ) was accounted for in the refinement calculations (w R 2=0.056 for 4183 reflections). The main structural features of BaGa 2 O 4 are layers of six-membered rings of GaO 4 tetrahedra perpendicular to the c -axis. The stacking of the layers parallel to c results in a three-dimensional framework containing tunnels, where the barium cations are located. Within a single layer two different types of ditrigonal-shaped six-membered rings are distinguished on the basis of relative orientation of up (U) and down (D) pointing apices of adjacent tetrahedra: one-fourth of the rings have an UDUDUD topology, whereas the sequences of directedness of the remaining rings is UUUDDD. The structure is isotypic with KAlGeO 4 . It is the first member of this structure family containing exclusively trivalent tetrahedral ions of only one chemical species and divalent nonframework cations within the channels.
Decolorization of Wastewater Produced in a Pyrolysis Process by Ozone: Enhancing the Performance of Ozonation

This paper shows the results of color removal from a wastewater produced in a plastic pyrolysis process by ozonation. The influence of parameters such as temperature, reactor geometry, UVA, ozone input, and finally spraying of wastewater on performance enhancement of the decolorization process will be discussed. Due to the long residence time of O3 molecules in the gaseous phase, recycling and spraying the wastewater in a pre-filled ozone chamber show a remarkable effect on decreasing the decolorization process time. At the end of this paper, an application of “micro-bubble producer” in this field, and its advantages will be introduced.
Cyclic Performance Analysis of Hydrogen/Bromine Flow Batteries for Grid‐Scale Energy Storage

This paper explores the critical factors dominating the cycle performance of the hydrogen/bromine redox flow battery (RFB). Carbon electrode oxidation to CO2 was seen as the dominant side reaction, which can be prevented by operating the cell below 1.4 V. Crossover of bromide species from the positive to the negative electrode, especially during charge, dominates the coulombic efficiency, and can result in dissolution of the Pt catalyst if an adequate hydrogen supply is not maintained. This paper also describes the tradeoffs in voltaic, energy, and coulombic efficiencies during cycling, including the determination of the peak energy efficiency with respect to the HBr concentration and current density. Long-term cycling demonstrates negligible cell-component degradation over 600 cycles (approximate to 3 months), with capacity loss caused by the bromine from the system, which can be mitigated by proper system design. The data and methodologies provided in this paper can be used to understand better the operation of this and other RFBs.
VARIATION IN GLYCOLYTIC POTENTIAL AND FRESH PORK QUALITY TRAITS ALONG THE LONGISSIMUS DORSI OF SLAUGHTER WEIGHT PIGS

The objective of this study was to determine the effects of loin muscle location on glycolytic potential (GP) and fresh pork quality traits. Seven sections (5-cm thick) from approximately between the eighth rib and fourth lumbar vertebra were evaluated. Numerous quality measurements were taken within each section. Ultimate pH was similar (P > 0.05) at all locations. Drip loss decreased (P < 0.01), while subjective firmness and color scores improved (P < 0.01) toward the posterior end of the loin. Minolta L* values (Minolta, Osaka, Japan) were highest (P < 0.01) in the anterior sections. Intramuscular fat was lower, but shear force and GP were higher in the middle sections than at the extremities (P < 0.01). In conclusion, GP and pork quality traits vary throughout the longissimus dorsi. However, differences in GP among sections were of low magnitude, and ultimate pH was unaffected by loin location. For studies that require multiple measurements of GP, samples should be taken in the region of the longissimus that yielded similar values, i.e., between the 10th rib and the third lumbar vertebra.
The study of interaction between graphene and metals by Raman spectroscopy

Different metal films (Co, Ni, Au, and Ag) were deposited on graphene and the interactions between these metals and graphene were studied by Raman spectroscopy. The Raman peaks were shifted after the deposition of metal films. The electron doping of graphene with cobalt contacts and the hole doping with the nickel contacts are the main reasons for Raman peak shift. However, for gold contacts and silver contacts with graphene, strain effect dominates Raman peak shift instead of charge transfer.
Chemical Reactivity of Reduced TiO2(110): The Dominant Role of Surface Defects in Oxygen Chemisorption

O2 chemisorption on reduced, rutile TiO2(110) with various concentrations of oxygen vacancies (Ov) and bridging hydroxyls (OHb) is investigated with scanning tunneling microscopy, temperature-programmed desorption, and electron-stimulated desorption. On the annealed surface, two oxygen molecules can be chemisorbed per Ov. The same amount of O2 chemisorbs on surfaces where each Ov is converted to two OHb’s by exposure to water (i.e., 1 O2 per OHb). Surfaces with few or no Ov’s or OHb’s can be created by exposing the hydroxylated surface to O2 at room temperature, and the amount of O2 that chemisorbs on these surfaces at low temperatures is only ∼20% of the amount on the annealed (reduced) surface. In contrast, the amount of chemisorbed O2 increases by more than a factor of 2 when the OHb concentration is enhanced—without changing the concentration of subsurface Ti interstitials. The results indicate that the reactivity of TiO2(110) is primarily controlled by the amount of electron-donating surface species .
A New Method of Heparinizing PLLA Film by Surface Entrapment

A new method of surface heparinizing biodegradable polymers was designed. A heparin-modified poly(L-lactic acid) (PLLA) system was developed by physically entrapping the heparin on the PLLA surface. The surface characterization and biological performance of these materials were carried out by SEM, attenuated-total-reflection spectroscopy, contact angle measurements, and platelet adhesion evaluations. The modification strategy was performed by reversible swelling of the PLLA surface following exposure to a solvent–nonsolvent mixture. This process resulted in the localized physical entrapment of the diffused heparin. X-ray photoelectron spectroscopy was used to confirm that control over the heparin surface density can be achieved by using set polymer treatment times. Platelet adhesion tests showed significant improvement in blood compatibility by the PLLA surfaces after modification.
Size dependence of the work function in InAs quantum dots on GaAs(001) as studied by Kelvin force probe microscopy

We have investigated a work function of single InAs quantum dots (QDs) on GaAs(001) correlating with the dot size by means of Kelvin force probe microscopy. The observed contact potential difference (CPD) of the single QD is lower than that of an InAs wetting layer, and increases with decreasing QD height. The height dependence of the CPD is well interpreted in terms of the quantum size effect by which the amount of accumulated charges in the QD is determined through the confinement energy levels in the QD.
Stoichiometry of thin silicon oxide layers on silicon

The composition of anodically and thermally grown silicon oxide layers was determined by backscattering and channeling measurements with 2.0‐MeV 4He+ ions. The oxide thickness was determined by ellipsometry and, for anodic films, the silicon removal rate was also determined by layer removal measurements. The surface layer consists of stoichiometric silicon dioxide plus a silicon‐rich transition layer between the substrate and the silicon dioxide. The number of silicon atoms in this layer was found to be 6 × 1015 atoms/cm2 (about three atomic layers).
Montmorillonite K10: Catalyst for Friedel–Crafts Alkylation of Indoles and Pyrrole with Nitroalkenes Under Solventless Conditions

Montmorillonite K10 was found to catalyze the Michael addition of indoles or pyrrole with nitroalkenes efficiently under solventless condition. The short reaction time, simple workup, and excellent yields were noteworthy. The green catalyst could be reused for three runs without considerable variation in yield.
Stability of H‐terminated BDD electrodes: an insight into the influence of the surface preparation

EIS, CV and XPS experiments were carried out to address the evolution of H‐terminated BDD electrochemical properties under intensive use and air aging. A drastic drop of apparent electron transfer rate k0′ was thus recorded using Fe(CN6)3–/4– as the redox mediator by identifying components of the Randles equivalent circuit. Excellent agreement was observed between theoretical and experimental curves. The feasibility of recovering and stabilizing high reactivity and reversible behaviour by applying a suitable electrochemical post treatment was then demonstrated. Such a treatment was developed empirically and seemed to significantly improve the electrode performances. On the basis of our results, we claim that the electrochemical evolutions observed are strongly linked to chemical termination modifications and partial inactivation of the electrode surface. Further research on the mechanisms that govern electron mediation at the diamond surface would be of high interest for better control of diamond electrode stability and reactivity towards their applications for bio‐electronic devices. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Highly efficient polycarbazole-based organic photovoltaic devices

We combined experimental and computational approaches to tune the thickness of the films in poly(N-9′-heptadecanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole) (PCDTBT)-based organic solar cells to maximize the solar absorption by the active layer. High power-conversion efficiencies of 5.2% and 5.7% were obtained on PCDTBT-based solar cells when using [6,6]-phenyl C61-butyric acid methyl ester (PC60BM) and [6,6]-phenyl C71-butyric acid methyl ester (PC70BM) as the electron acceptor, respectively. The cells are designed to have an active area of 1.0 cm2, which is among the largest organic solar cells in the literature, while maintaining a low series resistance of 5 Ω cm2.
Surface smoothing effect of an amorphous thin film deposited by atomic layer deposition on a surface with nano-sized roughness

Previously, Lau (one of the authors) pointed out that the deposition of an amorphous thin film by atomic layer deposition (ALD) on a substrate with nano-sized roughness probably has a surface smoothing effect. In this letter, polycrystalline zinc oxide deposited by ALD onto a smooth substrate was used as a substrate with nano-sized roughness. Atomic force microscopy (AFM) and cross-sectional transmission electron microscopy (XTEM) were used to demonstrate that an amorphous aluminum oxide thin film deposited by ALD can reduce the surface roughness of a polycrystalline zinc oxide coated substrate.
Propagation of a planar flame front studied by molecular dynamics

In this paper we study the propagation of a planar traveling wave in a nonisothermal autocatalytic reaction diffusion system. This is done by performing a series of molecular dynamics simulations for different densities and heat of reactions. In the special case where the reaction is isothermal, it is shown that the molecular dynamics simulation qualitatively resembles the approximative macroscopic description that is based on the reaction diffusion equation. Simulations for different densities and heat releases further show that the speed of propagation is not simply the minimum speed of the corresponding macroscopic equation and that the speed is always constant even though the Lewis number is greater than unity.
Galvanic Corrosion of a Copper Alloy in Lithium Bromide Heavy Brine Environments

Abstract Galvanic corrosion of the copper alloy 84% Cu-15% Zn-1% Ni was studied in 55wt% lithium bromide (LiBr) environments. The galvanic couples studied were: 84% Cu-15% Zn-1% Ni-Ti2, 84% Cu-15% .
SLIP FLOW AND HEAT TRANSFER OF A SECOND-GRADE FLUID IN A POROUS MEDIUM OVER A STRETCHING SHEET WITH POWER-LAW SURFACE TEMPERATURE OR HEAT FLUX

This article deals with the study of boundary layer flow of a second-grade fluid in a porous medium past a stretching sheet and heat transfer characteristics with power-law surface temperature or heat flux. The flow in the boundary layer is considered to be generated solely by the linear stretching of the boundary sheet adjacent to a porous medium, and boundary wall slip condition is assumed. In the energy equation effects of viscous dissipation, work done due to deformation and internal heat generation/absorption is taken into account. Closed form solutions are obtained for this problem.
Tight-Binding Quantum Chemical Molecular Dynamics Study on First Proton Transfer Process of ORR Catalyzed by Cobalt-Porphyrin Complex

We investigated oxygen reduction reaction (ORR) dynamics catalyzed by cobalt-porphyrin using our original novel tight-binding quantum chemical molecular dynamics method. First, we determined parameters for tight-binding calculation based on first-principles parameterization. We have successfully simulated a first proton transfer process of the oxygen reduction reaction with the explicit consideration of surrounding water molecules. The transferred proton formed hydrogen bonding with a water molecule and conformational change of the OOH species was observed. It was proved that our tight-binding quantum chemical molecular dynamics method is effective for the investigation of oxygen reduction reaction dynamics in large complex system.
Flexible photovoltaic technologies

Flexible photovoltaic (PV) devices have attracted enormous attention from academy and industry as a convenient alternative energy source for indoor and outdoor applications. Flexible PV panels can be easily integrated with infrastructures of various shapes and sizes, meanwhile they are light-weight and thus suitable for applications where weight is important. In this review, we will describe the progress that has been made in the field of flexible PV technologies. In addition, a summary will be provided with perspective on the future development of flexible solar cells and new opportunities offered by these devices.
Two-Dimensional Multiphase Behavior Induced by Sterically Hindered Conformational Optimization of Phenoxy-Substituted Phthalocyanines

Symmetrically substituted phthalocyanines (Pcs) with eight peripheral di-(tert-butyl)phenoxy (DTPO) groups self-organize on Ag(111) and Au(111) substrates into various assembly structures. These different structural phases were studied by scanning tunneling microscopy (STM). On the basis of high-resolution STM images, molecular models are provided for each phase that account for the observed unequal surface densities. Notably, the specificity of the studied Pc derivative featuring the peripheral phenoxy groups remarkably increases its conformational possibilities. Particularly, the rotational degrees of freedom allow all the DTPO substituents to be arranged above the plane of the Pc core, forming a bowl-like structure, which in turn enables the interaction of the Pc core with the metal substrate. The proximity of the Pc core to the metal substrate together with the steric entanglement between neighboring DTPO substituents causes significant retardation of the thermodynamic optimization of the conformations.
Comparative study of redox reactions of polyaniline films in aqueous and nonaqueous solutions

Etude de la variation avec le potentiel de polarisation de la conductivite electrique et de la densite de spin des films de PA en milieu aqueux et non aqueux. Dans tous les cas, observation de 2 paires de pics redox. Mise en evidence de la formation de radicaux cations au 1er pic anodique avec une conductivite electrique maximale pour ce pic. Discussion des resultats sur la base d'un modele de polaron
Preparation and crystal structure of lanthanum molybdenum silicon oxide (La3MO4SiO14), an unusual cluster compound of molybdenum

Preparation du compose a haute temperature par reduction electrolytique d'une phase fondue contenant Na 2 MoO 4 , MoO 3 et La 2 O 3 . Cristallisation dans le reseau orthorhombique, groupe Pnma. Affinement jusqu'a R=0,042. La structure presente des motifs triangulaires Mo 3 O 13 et des chaines d'octaedres MoO 6 a aretes communes. Coordination tetraedrique autour de Si et prismatique rhomboedrique autour de La
A Topological Analysis of Charge Densities in Diamond, Silicon and Germanium Crystals

The Hansen-Coppens multipole model of charge density has been fitted to highly accurate published experimental and theoretical structure factors for diamond, silicon and germanium crystals. Analysis of both model experimental and theoretical charge densities using the resulting model parameters was performed in terms of Bader's topological theory. The general topology of the charge density appeared to be identical for all crystals, containing the four possible types of critical points of rank three, and no non-nuclear attractors between neighboring atoms were found within achieved accuracy. Theoretical and experimental values of charge density and its Laplacian show quantitative and semiquantitative agreement, respectively, at the critical points of model charge densities. For Ge crystals, such agreement is worse at the ring critical point. These results suggest the possibility of semiquantitative (within 10-30%) study of the topological characteristics of highly accurate X-ray charge densities of crystals displaying shared interatomic interactions. Comparative topological analysis of the chemical bond in this series of crystals is discussed in terms of the quantum topological theory.
Improving Mobile Video

This dissertation deals with a well known problem the fact that consumer cameras are unable to capture the whole range of color luminance variations the human eye is able to perceive. Many widespread techniques, especially those related to High Dynamic Range, deal with this issue, focusing mainly on still images. Our focus in this work, however, is to study possibilities of the improvement of videos taken from mobile devices by the consumer through the application or extension of these techniques.
Diferencias entre el Nivel de Significancia alfa y el Valor P

Resumen: Comunmente los trabajadores de la salud y personas con poco conocimiento de la estadistica, cuando se involucran en investigacion de tipo cuantitativa, se ven abocados a realizar tecnicas estadisticas para cumplir con el analisis de la informacion resultante de un proceso de recoleccion de datos previo. Por lo general se plantean hipotesis que posterior al analisis de la informacion se puede aportar evidencia a favor o en contra de dichas hipotesis. Es en este punto donde, en muchas ocasiones, se encuentran en medio de la confusion al momento de interpretar el valor p y el error tipo I. En este documento se abordara el concepto de valor p y nivel de significancia, igualmente se aclarara la diferencia entre ellos. Revista Estomatologia 2008; 16(1):30-32. Palabras clave: Error tipo I. Error tipo II. Valor P. Hipotesis Nula. Estadistico de prueba. Summary: Usually health professionals and people with little knowledge of statistics when involved with quantitative research they are faced to make statistical techniques to fulfill the data analysis resulting from a previous data collection. Generally they state hypothesis and later the information analysis can support the evidence in favor or against such hypothesis. In that point commonly they are faced to confusion when they try to interpret p value and type I error. The concept of p value and significance level will be approached in this paper and the difference among them will be cleared. Key words: Type I error. Type II error. P value. Null hypothesis. Statistical of test.
Branching and gelation in atom transfer radical polymerization of methyl methacrylate and ethylene glycol dimethacrylate

Bulk copolymerization of methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EGDMA) was initiated by methyl α-bromophenylacetate (MBPA) and mediated by copper bromide (CuBr) ligated with 1,1,4,7,10,10-hexamethyltriethylenetetramine (HMTETA). The atom transfer radical polymerization (ATRP) of pure MMA yielded polymers with well controlled molecular weights and the homopolymerization was taken as a reference for the copolymerization analysis. The copolymerization experienced autoacceleration in rate due to a diffusion-controlled radical deactivation. The onset of autoacceleration came earlier with an increase in the EGDMA fraction. At low EGDMA fractions, the molecular weight versus conversion data deviated from linearity due to branching. The ratio of the copolymer molecular weight over homo-poly(methyl methacrylate) gave an estimate for the branching density, which increased initially and leveled off at high conversion. At high EGDMA fractions, the ATRP system experienced gelation. The pregel branching density increased with conversion, and at the gel point, it agreed with Flory's gelation theory assuming cross-linking free of cyclization. The branching densities at the high gel fractions were very close to the maximum values possibly achieved with the added EGDMA fractions. These results suggested that the ATRP system was very effective in preparing homogeneous polymer networks with a high cross-linking efficiency. POLYM. ENG. SCI., 45:720–727, 2005. © 2005 Society of Plastics Engineers
A REVIEW ON SMALL FILES IN HADOOP A NOVEL APPROACH TO UNDESTAND SMALL FILES PROBLEM IN HADOOP

Hadoop is an open source data management system designed for storing and processing large volumes of data, minimum size being 64MB. Storing and processing of Small Files smaller than the minimum block size cannot be efficiently handled by hadoop because Small Files results in lots of seeks and lots of hopping between the datanodes. A survey on the existing literature has been carried out to analyze the effect / solutions for the Small Files problem in hadoop. This paper presents the same and lists many effective solutions for this problem and further this paper says that there is a need to carry out lot of research on small file problem in order to attain effective and efficient solutions.