Miracle-dz/UniFAR-FTUs huggingface dataset:
Synthesis and transport properties of Bi2Te3 nanocomposites

Nanostructured Bi2Te3 compounds have been synthesized by a circulating reflux method. The morphologies of the nanopowders are mainly related to the surfactants and reactants used in the syntheses. Bi2Te3 nanocomposites were obtained by hot-pressing the mixture of nano and micro-powders of Bi2Te3 in different ratios. It is found that the electrical transport properties of the nanocomposites are different from conventional Bi2Te3 alloys. Electrical conductivity increased while the Seebeck coefficient changed from positive to negative with increasing temperature.
Fluidized bed and tray drying of thinly sliced mango (Mangifera indica) pretreated with ascorbic and citric acid

Summary The purpose of this work was to determine the influence of air temperature, sample diameter and antioxidants on water activity, moisture content and colour difference of thinly sliced mango in a fluidized bed and tray dryer. Mango samples were treated with antioxidants solutions (ascorbic and citric acid) before the drying process. Fluidized bed and tray drying of control and treated samples were carried out at two temperatures: 50 and 60 °C. A fractional factorial design 24−1 was used in both drying methods. The Newton semi-theoretical model was found to represent thin-layer drying kinetics of mango. For both drying types, moisture content of thinly sliced mango was well characterised (R2 ≥ 0.975) by the model. The temperature increment increases the drying constant and decreases the equilibrium moisture content and water activity of the dehydrated samples. Colour closest to the original colour of fresh mango was obtained when 2 cm diameter mango pretreated with citric acid (1%) was dehydrated by fluidized bed at 60 °C. In addition, it was observed that the drying time at equilibrium by using fluidized bed was lower (60 min) than the tray dryer (120 min).
Compound defects and thermoelectric properties in ternary CuAgSe-based materials

CuAgSe is a narrow band gap semiconducting material with superior carrier mobility and low lattice thermal conductivity, which are important and useful for high thermoelectric performance. However, its electrical and thermal transport properties are greatly affected by ionic deficiencies or compositional non-stoichiometry, which lead to a low thermoelectric figure of merit near room temperature. In this work, we systematically studied the compound defects in CuAgSe by tuning its starting chemical composition. We found that its phase purity is very sensitive to nominal chemical compositions. Only a small amount of Ag deficiency is allowed in CuAgSe to maintain phase purity, while the other non-stoichiometric compositions lead to impurity phases. Thermoelectric properties are weakly affected by these compound defects or impurity phases at 300 K, but greatly change at high temperatures. A single type carrier conduction is observed in CuAgSe, but a noticeable two-type carrier conduction is observed in the non-stoichiometric samples. This leads to an evident n to p conduction transition. Consequently, zT values in CuAgSe continuously increase to 0.6 at 450 K while the non-stoichiometric samples display considerably low values due to the contribution from both electrons and holes. The high zT value in n-type CuAgSe suggests that it is a promising thermoelectric material near room temperature.
Review of Drug Metabolism in Drug Discovery and Development

Drug metabolism is the process of chemical conversion of a drug to a metabolite preparatory to its elimination from the body. Four general categories of drug metabolic reactions occur: oxidations, reductions, conjugations, and hydrolyses. Metabolism is an important aspect of the clinical profile of a drug, since it is often a determinant of half-life, a source of drug–drug interactions, a reason for interindividual variability of drug response, and a source of toxicities. Keywords: biotransformation; reactions; cytochrome P450; enzymes; pharmacokinetics
Chemical Characterization of Dissolved Organic Matter (DOM) in Seawater: Structure, Cycling and the Role of Biology

Abstract : The goal of this thesis is to investigate three different areas relating to the characterization of dissolved organic matter (DOM). The first section used periodate over-oxidation to analyze the previously unidentified fraction of HMWDOM. The majority of the carbon in two HMWDOM samples was over-oxidation, including 70% of the aliphatic NMR signal, with a high degree of branching. Based on the HNMR spectra data, it was concluded that 6-deoxysugars were the primary compounds in the unidentified fraction of HMWDOM. In the second section, a new method was presented for the purification of individual underivatized amino acids hydrolyzed from HMWDOM, using cation exchange chromatography and high-pressure liquid chromatography (HPLC) with C18 and strong cation exchange (SCX) columns. Six amino acids were isolated from HMWDOM with sufficient purity and quantity for radiocarbon analysis. These amino acids had a range of delta(exp 14) C values, from 121% to -454%. The final section investigates biological controls on dissolved organic nitrogen (DON). Total hydrolyzable amino acids (THAA), and nucleic acids were measured for four incubations: a control, a grazer added, a zero virus, and a 10 times virus. Comparison to the control showed THAA and nucleic acid release were influenced by viruses but not grazers.
Identification and Selection of Major Carbon Dioxide Stream Compositions

A critical component in the assessment of long-term risk from geologic sequestration of CO2 is the ability to predict mineralogical and geochemical changes within storage reservoirs due to rock-brine-CO2 reactions. Impurities and/or other constituents selected for co-sequestration can affect both the chemical and physical (e.g. density, viscosity, interfacial tension) behavior of CO2 in the deep subsurface. These impurities and concentrations are a function of both the industrial source(s) of the CO2, as well as the carbon capture technology used to extract the CO2 and produce a concentrated stream for geologic sequestration. This report summarizes the relative concentrations of CO2 and other constituents in exhaust gases from major non-energy related industrial sources of CO2. Assuming that carbon-capture technology would remove most of the incondensable gases N2, O2, and Ar, leaving SO2 and NOx as the main impurities, we selected four test fluid compositions for use in geochemical experiments. These included: 1) a pure CO2 stream representative of food grade CO2 used in most enhanced oil recovery projects: 2) a test fluid composition containing low concentrations (0.5 mole %) SO2 and NOx (representative of that generated from cement production), 3) a test fluid composition with higher concentrations (2.5 mole %) of SO2, and 4) and test fluid composition containing 3 mole % H2S.
A Direct Sol‐Gel Synthesis Method for Incorporation of Transition Metals into the Framework of Ordered Mesoporous Materials

A series of ordered mesoporous cobalt silicate molecular sieves with variable Si/Co molar ratios were hydrothermally synthesized. The materials were characterized by powder X‐ray diffraction (XRD), N2 adsorption, temperature programmed reduction (TPR), and transmission electron microscopy (TEM). TPR and TEM results indicate that Co introduced by this method is incorporated into the framework of the ordered mesoporous materials rather than residing as Co3O4 particles in the pore system. XRD and N2 adsorption experiments reveal that the interplanar Bragg spacing, surface area, and pore width of the materials are tunable as a function of the bulk Si/Co molar ratio. The surface areas of the materials range from ∼1300 m2/g (unmodified siliceous mesoporous ordered material) to ∼500 m2/g (maximum incorporation of Co before structural breakdown), with the Barrett‐Joyner‐Halenda (BJH) model pore widths varying from 2 to 3 nm, respectively. Vanadium was also introduced by the same method to demonstrate the applicability of the method.
The Diels‐Alder Reaction Quinones and Other Cyclenones

Quinones and other cyclenones react by 1,4-addition with conjugated dienes. A typical example is the reaction of butadiene with p-benzoquinone yielding the diketohexahydronaphthalene. The direct synthesis of quinones with other cyclenones may be extended to provide a route to the preparation of fused-ring aromatic systems. It is also possible to prepare fused-ring ketones containing angular substituents. Diene syntheses described in this chapter may lead to the synthesis of compounds of steroidal structure. The stereochemcial configurations of Diels-Alder addition products have been discussed elsewhere in this series, This problem is exceedingly complex with products described in this chapter and is impossible to predict stereochemical configurations of the adducts with any certainty. Keywords: Diels-Alder reaction; quinones; cyclenones; benzoquinone; naphthaoquinones; fused-ring ketones; diene additions; experimental conditions
Transfer of Energy from High-Frequency to Low-Frequency Modes.

Abstract : In some recent experimental studies, we observed that energy can be transferred from high-frequency to low-frequency modes in structures with weak nonlinearities. In these experiments, a structure was subjected to a simple-harmonic, low-amplitude excitation. The frequency of the excitation was near one of the high natural frequencies; yet after a very long time the contribution of the first mode to the multi-frequency response was larger than the contribution of the high-frequency mode that was directly excited. Subsequently, we developed analytical models to explain the interactions between widely spaced modes of structures and used them to determine conditions under which energy can be transferred from high-frequency to low-frequency modes, as observed In the experiments.
Letter. Reduced As components in highly oxidized environments: Evidence from full spectral XANES imaging using the Maia massively parallel detector

Abstract Synchrotron X-ray fluorescence (SXRF) and X-ray absorption spectroscopy (XAS) have become standard tools to measure element concentration, distribution at micrometer- to nanometer-scale, and speciation (e.g., nature of host phase; oxidation state) in inhomogeneous geomaterials. The new Maia X-ray detector system provides a quantum leap for the method in terms of data acquisition rate. It is now possible to rapidly collect fully quantitative maps of the distribution of major and trace elements at micrometer spatial resolution over areas as large as 1 × 5 cm2. Fast data acquisition rates also open the way to X-ray absorption near-edge structure (XANES) imaging, in which spectroscopic information is available at each pixel in the map. These capabilities are critical for studying inhomogeneous Earth materials. Using a 96-element prototype Maia detector, we imaged thin sections of an oxidized pisolitic regolith (2 × 4.5 mm2 at 2.5 × 2.5 μm2 pixel size) and a metamorphosed, sedimentary exhalative Mn-Fe ore (3.3 × 4 mm2 at 1.25 × 5 μm2). In both cases, As K-edge XANES imaging reveals localized occurrence of reduced As in parts of these oxidized samples, which would have been difficult to recognize using traditional approaches.
Study of the excited-state absorption properties of polymethine molecules

This dissertation investigates excited-state nonlinearities in a series of polymethine dyes for the application of nanosecond optical limiting. Optical limiters are devices that for low intensity light exhibit a high linear transmittance, but for high intensity light strongly attenuate the incident radiation. These devices would serve to protect optical sensors from intense laser radiation by clamping the maximum energy allowed through an optical system below the damage threshold of the sensor. The search is ongoing for optical materials that are both broadband and have high damage thresholds to be effective materials for limiting applications. Polymethine dyes are promising compounds due to a strong and broad excited-state absorption (ESA) band in the visible region. However, the effectiveness of polymethine molecules as applied to optical limiting is hindered by a saturation of the ESA process at high fluences. Experiments and theoretical modeling are performed to determine the root causes of this saturation effect in both the picosecond and nanosecond time regime. The polymethine molecules studied have chromophore lengths from dito pentacarbocyanine (2 to 5 -CH=CHgroups) with various bridge structures. This allows us to develop relationships between the molecular parameters of the polymethine molecules and overall nonlinear absorption performance. The experiments conducted included femtosecond white light continuum pumpprobe experiments to measure ESA spectra, picosecond two-color polarization-resolved pumpprobe to measure excited-state dynamics and the orientation of transition dipole moments, and picosecond and nanosecond optical limiting and z-scans. From these experiments we are able to
Modification of yttria-stabilized tetragonal zirconia for IT-SOFC electrolyte applications

Problemy wspo czesnej energetyki, zwi zane z malej cymi zasobami paliw kopalnych i rosn cym zanieczyszczeniem rodowiska, zmuszaj do szukania jak najbardziej energooszcz dnych i proekologicznych rozwi za , ktore maj na celu racjonalne i zrownowa one wykorzystanie zasobow energetycznych, przy uwzgl dnieniu odnawialnych i alternatywnych rode energii. Zgodnie z dokumentem politycznym „Strategia Rozwoju Energetyki Odnawialnej”, opracowanym przez Ministerstwo rodowiska i ustanowionym przez Sejm Rzeczypospolitej Polski 23 wrze nia 2001 roku, udzia energii ze rode odnawialnych w ogolnym bilansie paliwowo-energetycznym ma wzrosn do 14% w roku 2020. Jednak e ze wzgl dow ekonomicznych nie jest mo liwe nag e przej cie z tradycyjnych technologii wytwarzania energii elektrycznej w elektrowniach stacjonarnych zasilanych paliwami sta ymi, p ynnymi czy gazem ziemnym do technologii odnawialnych (energia s o ca, wiatru, przyp ywy morza, wodna, geotermalna). St d narodzi si pomys na rozwijanie nowych technologii, okre lanych mianem „technologii po rednich”, ktore z jednej strony pozwoli yby na efektywne wykorzystanie paliw zasilaj cych tradycyjne urz dzenia, a z drugiej − znacznie obni y yby poziom emisji gazow cieplarnianych. Do takich przysz o ciowych technologii po rednich mo na zaliczy ogniwa paliwowe. Mody kacja tetragonalnej odmiany cyrkonii stabilizowanej tlenkiem itru z przeznaczeniem na elektrolity do ogniw paliwowych typu IT-SOFC
Dynamics of the detonation products of lead azide. IV. Laser shadowgraphy of expanding species

Laser resonant shadowgraphy (LRS) and laser nonresonant shadowgraphy (LNRS) are used to monitor the detonation products of lead azide. Photographs of the cloud of products are obtained via illumination with a doubled dye laser tuned on‐resonance to the 3P1o‐3P0 transition of the Pb atom at 283.31 nm, and off‐resonance at 284.31 nm. The versatility of the diagnostics and its applicability to detonation products expanding into vacuum and into atmospheric pressure air are demonstrated. The LRS monitors the density gradients of both lead atoms and solid particles formed in the detonation, whereas the LNRS detects only the latter. Expansion into vacuum through a nozzle leads to an increase in the velocity (from ∼4.5 to ≳5 km/s) and density of the atoms and to a decrease in the density of the particles. The LRS measurements show that the expansion of both products in air is relatively slow (∼0.75 km/s) and leads to production of shock waves. From the shape of the shock waves created by an obstacle when the prod.
Integração de dados do quickbird e atributos do terreno no mapeamento digital de solos por redes neurais artificiais

This study evaluated different environmental variables in the digital soil mapping of an area in the northern region of Minas Gerais State, using artificial neural networks. The environmental variables terrain attributes (slope and compound topographic index), the quickbird bands 1, 2 and 3, and lithology were evaluated. The importance of each of the variables in the classification was tested. The "Java Neural Network Simulator" was used with the backpropagation learning algorithm. For each dataset a neural network was created to predict the soil mapping units, and the map produced by the nets was compared with the conventional, to show the general accuracy of each one. The best classification was achieved when all variables were used, with an accuracy of 67.4 % compared to the the conventional soil map. Of the variables, slope was most significant, because when excluded from the dataset, the classification was worst (accuracy 33.7 %). This result showed that the approach can contribute to overcome some problems of soil mapping in Brazil, especially at scales larger than 1:25,000, with faster and cheaper execution, mainly if remote sensing data with high spatial resolution and an affordable price are available, and good digital elevation models to generate the terrain attributes in the geographical information systems.
Influencia del intercambio iónico de clinoptilolita natural en la cinéticade adsorción de CO2, N2y CH4a 20 °C

In this work, the adsorption kinetics of pure C O 2, N 2y C H 4 on natural clinoptilolite (ZSL) from Villa de Reyes, San Luis Potosi , Mexico, and on clinoptilolit e samples exchanged partially with N a + , K +, C a2 +y H +(ZSL-Na, ZSL-K, ZSL-Ca, ZSL-H) was studied at 2 0 °C using a high volumetric system. The adsorption uptake for th e ZSL-Na, ZSL-K, ZSL-Ca, and ZSL samples, at short contact times , decreased in the order C O 2> N 2> C H 4, whereas for the ZSL-H sa m - ple decreased in the order C O 2> C H 4> N 2. The ZSL-Ca y ZSL-N a samples could be recommended for the separation of C O 2/ C H 4an d N 2/ C H 4mixtures .
Automated estimation of leaf area index from grapevine canopies using cover photography, video and computational analysis methods

Background and Aims Monitoring of canopy vigour is an important tool in vineyard management to obtain balanced vines (vegetative vs reproductive organs). Leaf area index is the main parameter representing canopy vigour. Our aim was to test an automated computational method to obtain leaf area index and canopy vigour parameters from grapevines with digital photography and video analysis using MATLAB programming techniques for rapid data uptake and gap size analysis. Methods and Results The proposed method was tested against allometry at a Chilean experimental site planted with cv. Merlot. A temporal and spatial assessment of the method was also tested in a drought and drought/recovery experiment with cv. Chardonnay in the Riverland, South Australia. These data were geo-referenced and compared to the normalised difference vegetation index extracted from the WorldView-2 satellite images at a 2 m2 per pixel resolution. Conclusions The maximum leaf area index data obtained with cover digital photography and video analysis are an accurate, cost-effective and easy-to-use method to estimate spatial and temporal canopy LAI and structure when compared to standard measurements (allometry and plant canopy analyser). Significance of the Study This study has demonstrated that the method proposed is an accurate and inexpensive tool for application in experiments and by the industry to monitor spatio-temporal distribution of vigour.
Discovering human protein diversity

Current emphasis on discovering and correlating human genetic variations lays the foundation for future studies of human protein diversity. Protein posttranslational processing, along with the translation of genetic variations, results in a complex, variable human proteome. Analyzing these protein variations on a grandeur scale has become feasible with the advent of mass spectrometry. Mass spectrometry is the only detection method today that can universally provide information about specific protein structural modifications, without a priori knowledge of the modification. However, high-throughput separation approaches are needed to effectively prepare the proteins for mass spectrometric interrogation. Such are the immunoaffinity separations that target single proteins by using highly specific antibodies for their affinity retrieval from the biological fluids. The resulting combination of immunoaffinity separation with MALDI-TOF mass spectrometry, termed Mass Spectrometric Immunoassay (MSIA), has been recently applied in two large studies of protein diversity. The results of these studies reveal a human protein diversity that is far more complex than the variations observed at the genetic level. Assessing the human proteome variations among and within populations will be an important future undertaking with significant clinical and diagnostic implications.
Analysis of Polar Cholesterol Oxidation Products: Evaluation of a New Method Involving Transesterification, Solid Phase Extraction, and Gas Chromatography

Monitoring cholesterol oxidation products is important in the evaluation of the potential health risks associated with lipid oxidation. In the present study, a method allowing quick and reliable analysis of polar cholesterol oxidation products was evaluated. After Soxhlet-lipid extraction, the fat was transesterified under mild conditions, thereby minimizing degradation and allowing determination of the free and esterified cholesterol oxides. Sample fractionation was achieved with aminopropyl solid phase extraction cartridges and a stepwise elution with hexane, hexane/methyl tert-butyl ether, and acetone to separate polar cholesterol oxides from cholesterol and other lipid products. Further analysis of the trimethylsilyl derivatives was performed by gas chromatography with detection by flame ionization or mass spectrometry. A phytosterol oxide such as sitosterol α-epoxide (24α-ethyl-5α,6α-epoxycholestan-3β-ol) was employed for the first time as an internal standard for the quantification of cholesterol ox.
HEAT TRANSFER ANALYSIS FOR A VAPOR BUBBLE

In this work, we review the basic heat-transfer mechanisms of a vapor bubble immersed in an unbounded and subcooled liquid. The governing equations for the vapor and liquid phases, together with appropriate initial and boundary conditions, are presented in dimensionless form. In particular, if the characteristic inertial times are smaller than the characteristic process times, the evolution for the radius of the bubble depends basically on the Jakob number, Ja, and the vapor densities ratio, ρ. Recognizing that the Jakob number is very large compared with unity, the resulting governing equations are modeled by a thermal boundary layer, adjacent to the radius of the bubble. We show that higher order corrections due to curvature effects, associated with conductive and convective heat terms of the energy equation for the liquid, characterize the collapse of the bubble. For different values of Ja and ρ, the numerical results for the evolution of the nondimensional radius of the bubble,a, and for the corresponding nondimensional temperature profiles, θ, show that the ending collapse state has a singular behavior, which we have denoted as a “thermal runaway. ”