Miracle-dz/UniFAR-FTUs huggingface dataset:
Experimental Aspects of Electron Channeling Patterns in Scanning Electron Microscopy

Material depths responsible for electron channeling patterns are estimated from the visibility of the patterns obtained at 20 to 50 kV in the reflective mode of the scanning electron microscope, observing Al and Cu specimens on which Al and Cr are separately deposited at various thicknesses. The maximum visible thickness can be expressed by approximately 1.5/μ0, where μ0 is the mean absorption coefficient for the deposited material. Effective backscattering coefficients of transmitted electrons are derived from empirical data for the backscattering yield and transmissivity of thin films. The theory of Hirsch and Humphreys is modified with these coefficients. This phenom-enological treatment removes an appreciable discrepancy in the channeling signal estimates which has been clarified in a previous report. Further investigations for elucidating the validity of the assumptions used in the treatment are described. Die Materialtiefen, die fur Elektronenkanalleitungsdiagramme eine Rolle spielen, werden aus der Beobachtbarkeit der Diagramme bei 20 und 50 kV in Reflexionsmode eines Rasterelektronen-mikroskops berechnet, wobei Al- und Cu-Proben, auf denen Al und Cr getrennt mit verschiedenen Dicken aufgebracht wurden, beobachtet werden. Die maximale sichtbare Dicke last sich nahe-rungsweise durch 1,5/μ0 ausdrucken, wobei μ0 der mittlere Absorptionskoeffizient des aufgebrachten Materials ist. Effektive Ruckstreukoeffizienten der transmittierten Elektronen werden aus den empirischen Werten der Ruckstreuausbeute und der Durchlassigkeit der dunnen. Schichten abgeleitet. Mit diesen Koeffizienten wird die Theorie von Hirsch und Humphreys modifiziert. Diese phanomenologische Behandlung beseitigt eine betrachtliche Diskrepanz in den Berechnungen des Kanalleitungssignals, worauf in einer fruheren Arbeit hingewiesen wurde. Weitere Unter-suchungen zur Klarung der Gultigkeit der im Verfahren benutzten Annahmen werden beschrieben.
Evolutionary Computing Assisted Visually- Imperceptible Hybrid Cryptography and Steganography Model for Secure Data Communication over Cloud Environment

– The exponential growth of communication technologies and related application environments has broadened the cloud computing ecosystem horizon to meet major communication needs. However, in-parallel upsurge in online attacks, security breaches or allied intrusion events has alarmed industries to ensure optimal data security. Unlike text data transmission, image, or other multimedia communication over the cloud requires computational efficiency, imperceptibility, etc. to meet attack-resilient transmission. Amongst the major available security systems, the combination of cryptosystems and steganography has been identified as an augmented security model for data transmission. However, it demands enhancement in both stages to meet cloud-specific communication efficiency. Considering it as motivation, in this paper an efficient Visually Imperceptible Hybrid Crypto-Steganography (VIHCS) model is developed using Hybrid Cryptosystems followed by Adaptive Genetic Algorithm assisted Least Significant Bit (LSB) embedding process. We developed a novel Hybrid Cryptosystem by strategically applying Advanced Encryption Standard (AES) and Rivest–Shamir–Adleman (RSA) algorithms to secure secret data to be embedded in a cover image. In addition, the use of the Adaptive Genetic Algorithm based Optimal Pixel Adjustment (AGA-OPAP) strengthened the Least Significant Bit embedding while retaining the best possible image quality and visual imperceptibility. The proposed model achieved higher security, high embedding capacity as well as image quality, which is vital for cloud communication. To perform LSB embedding we applied 2D-Discrete Wavelet Transform (2D-DWT-2L) method with 8×8 dimensional block-wise embedding. It helps to achieve better embedding efficiency in conjunction with the AGA-OPAP model. Simulation results and respective visio-statistical assessment revealed that the proposed VIHCS model can accomplish better performance and reliable secure data communication over the cloud environment. Thus, the VIHCS model achieves maximum possible imperceptibility and hence can avoid attacks-such as steganalysis based attack or RS-attacks.
Spectrophotometric determination of total monoterpenols at low concentrations

A method for the determination of low concentrations of monoterpenols in biological samples has been developed. Using phase separation to extract steam distillates and subsequent spectrophotometric determination with sulphuric acid-vanillin reagent, it is possible to determine as little as 3–4 p.p.b. of total monoterpenols.
Facile Method for Determining the Aspect Ratios of Mineral Dust Aerosol by Electron Microscopy

Mineral dust is the second largest atmospheric emission by mass and one of the least understood sources. The shape of the particles depends on their composition and has implications for particle optical properties and reactive surface area. Mineral dust particles are often approximated as spheroids to model their optical properties. In this study, scanning electron microscopy (SEM) is used to measure the aspect ratios of calcite, quartz, NX-illite, kaolinite (KGa-1b and KGa-2), and montmorillonite (STx-1b and SWy-2). In addition to traditional SEM images of the top of the particles, the SEM substrates are oriented approximately normal to the electron beam in order to image the side of the particles. In this manner, aspect ratios for the top and side orientation of the particles are determined. Calcite particles have an aspect ratio of approximately 1.3 in both orientations, while quartz particles have an aspect ratio of 1.38 in the top orientation and 1.64 in the side orientation. The clay minerals studied all exhibited plate-like structures with aspect ratios of 1.35 to 1.44 for the top orientation and 4.80 to 9.14 for the side orientation. These values are used to estimate the specific surface areas (SSAs) of the minerals, which are compared to Brunauer-Emmett-Teller (BET) surface area measurements. Through this study, we present a simple method for determining the aspect ratios of aerosolized samples, rather than relying on literature values of model systems. As a result, this technique should provide a better method for determining the optical properties of mineral dust particles. Copyright 2014 American Association for Aerosol Research
A kinetic study on the decomposition of 5-hydroxymethylfurfural into levulinic acid

Levulinic acid (LA), accessible by the acid catalyzed degradation of biomass, is potentially a very versatile green intermediate chemical for the synthesis of various (bulk) chemicals for applications like fuel additives, polymers, and resin precursors. We report here a kinetic study on one of the key steps in the conversion of biomass to levulinic acid, i.e. the reaction of 5-hydroxymethylfurfural (HMF) to levulinic acid. The kinetic experiments were performed in a temperature window of 98–181 °C, acid concentrations between 0.05–1 M, and initial HMF concentrations between 0.1 and 1 M. The highest LA yield was 94% (mol/mol), obtained at an initial HMF concentration of 0.1 M and a sulfuric acid concentration of 1 M. The yield at full HMF conversion is independent of the temperature. An empirical rate expression for the main reaction as well as the side reaction to undesired humins was developed using the power law approach. Agreement between experimental and model data is good. The rate expressions were applied to gain insights into optimum process conditions for batch processing.
Synthesis of the first organometallic miktoarm star polymer

The first organometallic miktoarm star copolymer, PFS(PI) 3 (PFS = polyferrocenyldimethysilane, PI = polyisoprene) with PDI of 1.04 was synthesized through anionic polymerization by using SiC 4 as the coupling agent and its well-defined structure was characterized by using GPC and 1 H NMR spectroscopy. In contrast to analogous diblok copolymers with similar PFS volume fractions which self-asemble to form cylindrical structures, PFS(PI) 3 formed unimolecular micelles in the PI selctive solvent, hexane.
Preparation and reactions of 3-[3-(aryl)-1,2,4-oxadiazol-5-yl]: propionic acids

Neste artigo descrevemos as sinteses dos acidos 3-[3-(aril)-1,2,4-oxadiazol-5-il] propionicos 3a-g, com alto rendimento, a partir das arilamidoximas 1a-g e do anidrido succinico. Os 1,2,4-oxadiazois 3a-f tambem foram obtidos fazendo-se a reacao em um forno de microondas domestico. Avaliacoes farmacologicas preliminares demonstraram que os compostos 3b-e possuem propriedades analgesicas. Calculos ab-initio com base sto-3g foram realizados com os compostos 3a, 4a, 5a e 6a.
Synthesis and Study of the Thermal and Chiro-Optical Properties of Polyacetylenes with Bulky Side Groups: Poly(1-ethynyl-4-biphenyl), Poly(1-ethynyl-4- phenoxybenzene) and Poly(1-ethynyl-4-pentylbenzene)

The monosubstituted acetylenes 1-ethynyl-4-biphenyl, 1-ethynyl-4-phenoxybenzene and 1-ethynyl-4-pentylbenzene were polymerized to the corresponding polyacetylenes with bulky side substituents: PEBIP, PEPHENO and PEPB, respectively, using a Rh(I) complex as polymerization catalyst. The FT-IR and UV-VIS spectra of PEBIP, PEPHENO and PEPB were studied using the corresponding spectra of polyphenylacetylene (PPA), polytolylacetylene (PETOL) and poly(1-ethynyl-naphthalene) PEN as reference. Based on the spectral analysis, high cis-trasoid structures were assigned to PEBIP, PEPHENO and PEPB. The specific optical rotation of PEBIP, PEPHENO and PEPB was measured in the chiral solvent α (-)pinene and, only for PEPB, also in α (+)pinene. It was found that even at low concentration PEBIP, PEPHENO and PEPB cause changes in the specific optical rotation of the chiral medium where they have been dissolved. This phenomenon has not been observed when toluene or atactic polystyrene are dissolved in the same chiral solvent in similar concentration. This suggests that the polyacetylenes with bulky side groups are able to rearrange in a helical configuration (prevalently right-handed or vice-versa, depending on the type of chiral medium used) once hosted in a chiral medium giving a contribution to the chirality of the solvent where they have been dissolved. The thermal stability of PEBIP, PEPHENO and PEPB was studied under N2 flow by thermal analysis (TGA, DTG and DTA) in comparison to reference monosubstituted polyacetylenes PPA, PETOL and PEN. The results show that the thermal stability of monosubstituted polyacetylenes is greatly improved by the presence of bulky substitutents as theoretically expected, and similarly, also the char-forming tendency increases with the bulkiness of the side groups.
CFD Simulation of Solids Suspension in Mixing Vessels

A CFD approach for predicting minimum impeller speed (Njs) to achieve complete off-bottom solids suspension in mechanically-agitated vessels is presented. The method is based on observing the simulated transient profiles of solids volume fraction for the layer of cells adjacent to the vessel floor and has been shown to be reliable and robust. Predicted Njs values for typical impeller systems were compared with well-known empirical correlations and good agreement was obtained. On presente une methode CFD de prediction de la vitesse de turbine minimum (Njs) pour realiser des mises en suspension completes dans des reservoirs agites mecaniquement. La methode repose sur l'observation des profils transitoires simules de fraction volumique de solides dans la couche de cellules proches du fond du reservoir et on montre qu'elle est fiable. Les valeurs de Njs predites pour des turbines typiques sont comparees avec des correlations empiriques bien connues et un bon accord est obtenu.
Structural Investigations of Octadecylphosphonic Acid Multilayers

In this work, different multilayer conformations of a linear amphiphilic molecule, octadecylphosphonic acid (OPA), were investigated by atomic force microscopy (AFM), X-ray reflectivity, and X-ray diffraction. It was found that these molecules spontaneously pack into well-organized self-assembled bilayers (SABs) when the structures are formed inside concentrated solutions and/or after slow solvent evaporation. The molecular structure of an OPA SAB was observed to be dependent on its position along a stack of bilayers: when the SAB is at, or close to, the stack surface, OPA molecules are vertically aligned and form 5 nm thick bilayers; when it is in the middle of a stack of hundreds, or thousands, of bilayers, OPA molecules are tilted and form 3.4 nm thick bilayers. The van der Waals interactions among the long OPA alkyl chains were used to explain and also predict some features of the molecular arrangement inside both bilayer types. Using the AFM technique, which also enabled the application of pressure .
Reforma do sector público hospitalar : programa de empresarialização de 34 hospitais portugueses

Os hospitais empresarializados (hospitais SA) romperam com o preconceito de que não é possível fazer mudanças na saúde, mobilizando todos os agentes em sentido convergente e conquistando ganhos de eficiência num curto intervalo de tempo. Os hospitais SA são o meio (instrumento), e não o fim, para obter maior eficiência (objectivo) na afectação dos recursos e na gestão da capacidade existente na rede pública de prestação de cuidados. Os hospitais SA constituíram-se como um poderoso catalisador da reforma estrutural do sector hospitalar português (modelo de financiamento, avaliação do mérito no desempenho) e um incubador de novas ideias e experiências (benchmarking sistemático, inovação na gestão da lista de inscritos para cirurgia). O primeiro ano de actividade saldou-se por um significativo aumento de eficiência (redução de 5,8% nos custos unitários), fruto de um considerável aumento de produção e da contenção dos custos operacionais. O esforço desenvolvido melhorou o acesso e o nível de qualidade e de serviço, contribuindo para futuros ganhos de saúde sustentáveis. 1. Cumprir o Programa do XV Governo Constitucional (2002-2004)
Effect of Precooling Step on Formation of Soymilk Freeze-Gel

A precooling step is necessary to convert heated soymilk to freeze-gel. In order to estimate the significance of precooling, soymilk was precooled at various temperatures and then frozen. Based on the appearance and stress-strain curve of thawed soymilk which was heated, precooled and freeze-stored, precooling at —5°C was most suitable for freeze-gelation. Although the effects of precooling temperatures on precipitation levels, syneresis and SDS-PAGE patterns were relatively small, there were great differences in freezing curves and ice crystal morphology. It was very important that the precooling temperature be lower than the freezing point of soymilk in order to form small and spherical ice crystals. The uniform distribution of these small ice crystals was considered to be important for the gel-like texture.
Writing Self-Assembled Mesostructured Films with In situ Formation of Gold Nanoparticles

We have developed an integrated technology that allows patterning and formation of gold-nanoparticles in self-assembled mesoporous films in a single step; this technique allows fabrication of patterned structures with high aspect ratios in a direct, simple, and reproducible way. We have used high intensity X-rays that interact with the mesoporous matrix through different processes, by removing the organic templates, increasing the polycondensation of the organic−inorganic silica network, and partially removing the methyl groups bonded in the hybrid matrix. The final material, after patterning and chemical etching, exhibits gold nanoparticles of few nanometers homogeneously dispersed in the porous matrix.
Dynamic light scattering from cetyltrimethylammonium bromide micelles. Intermicellar interactions at low ionic strengths

Quasi-elastic light scattering measurements have been performed on aqueous solutions of CTAB (cetyltrimethylammonium bromide). Theoretic fits to the measured diffusion coefficients at low NaBr were obtained by using the generalized Stokes-Einstein equation expanded to first order in the surfactant concentration (including both thermodynamic and hydrodynamic terms), with a pair-interaction potential taken from Dlvo theory. Good fits are obtained at low NaBr concentrations by assuming a constant micellar radius for each temperature and assuming that the remaining parameters (aggregation number, fractional ionization, and Hamaker coefficient) are independent of temperature. This procedure yields an unambiguous value for the fractional ionization alpha for CTAB micelles: alpha = 0.22. The limits of validity of the theoretic fitting procedure (previously applied by Corti and Degiorgio to the system sodium n-dodecyl sulfate (SDS) + NaCl) are discussed. 65 references.
The role of the coffee industry in sustainable economic development in Vietnam

Article history: Received: October 27, 2020 Received in revised format: November 26 2020 Accepted: December 9, 2020 Available online: December 9, 2020 The aim of this research is to analyze the impact of coffee industry on economic growth of Vietnam. This research has used historic data for coffee production, consumption, exports, and coffee stock for Vietnam, thus this research has followed a quantitative design. The data in this research has been collected from the time period ranging from 1990 to 2018. There are several techniques that were applied in E-views such as descriptive statistics, bounds test, and autoregressive distributed lag model. The results of ARDL model indicate that in the short run coffee industry has an influence on the economic growth in Vietnam. It can be stated that for the short-run the null hypothesis is rejected stating that domestic consumption, exportable consumption, gross opening stock, and total coffee production have impacts over the gross domestic product (GDP) of Vietnam. The results of Bounds test show there is a significant impact of coffee industry on the economic growth of Vietnam in the long run as well. © 2021 by the authors; licensee Growing Science, Canada
A Simple Algorithm for the Calculation of Kinetic Energy Release Distributions

A simple algorithm is presented for the determination of kinetic energy release distributions from metastable peak shapes. The corresponding IBM PC program takes into account instrumental effects (such as resolution) and can also be used to simulate metastable peak shapes from known kinetic energy release distributions. The program is fast, easy to use and easy to apply to various instrument geometries. The program determines kinetic energy release distribution automatically and can be used for narrow, for dish-topped and for “composite” peak shapes as well.
Fabrication of Highly Crystalline Corundum-Structured α-(Ga1-xFex)2O3 Alloy Thin Films on Sapphire Substrates

Highly crystalline corundum-structured α-(Ga1-xFex)2O3 alloy thin films were fabricated on c-plane sapphire substrates by using a mist chemical vapor deposition method. The full-widths at half maximum of X-ray diffraction rocking curves were smaller than 100 arcsec for the entire range of x from 0 to 1. Optical band gaps were artificially tuned to a value between those of α-Ga2O3 and α-Fe2O3, that is, 2.2 and 5.3 eV with changing the Fe content x in the films. Magnetic measurements revealed ferromagnetic properties of a α-(Ga1-xFex)2O3 (x = 0.24) thin film at 110 K.
Interactions between Single-Walled Carbon Nanotubes and Polyethylene/Polypropylene/Polystyrene/Poly(phenylacetylene)/Poly(p-phenylenevinylene) Considering Repeat Unit Arrangements and Conformations: A Molecular Dynamics Simulation Study

Although there is plenty of research work being done in the field of carbon nanotube reinforced composite materials, no special attention has been paid to the factors of the polymer's repeat unit arrangement and conformation. In this paper we use molecular dynamics simulation based on a Condensed-phase Optimized Molecular Potentials for Atomistic Simulation Studies (COMPASS) force field to study the interactions between five types of polymers and (10, 10) single-walled carbon nanotubes (SWNTs). When we study the interactions, we pay special attention to the polymer's different repeat unit arrangements and different conformations. We find that the interaction strength between the poly(phenylacetylene) molecules and SWNTs is obviously influenced by these factors, and the degree of the poly(p-phenylenevinylene) wrapping around the SWNT is associated with its repeat unit arrangement. Based on the present simulations, we think that the nanocomposite should have high mechanical properties if the polymer with an.
Evaluation of a Compact Differential Cell for Secondary pH Measurements by a Bilateral Interlaboratory Comparison

This work presents a new differential potentiometric cell for the standardization of pH buffer solutions and its evaluation, by means of a bilateral interlaboratory comparison, in relation to a traditional Baucke cell. The results obtained with the two cells were exactly the same for three of the pH buffer solutions analyzed (1.68, 4.01, and 6.86) and similar to each other for the remaining buffer solution (9.18). The new cell showed an average measurement time of only 21 minutes, in comparison with one to three hours for other cells described in the literature (including the Baucke cell).
Indication Ion Square Wave Voltammetric Determination of Thiamine and Ascorbic Acid

Abstract Cd2+ ion was used as an electrochemical indicator to detect VB1 or Vc using square ware voltammetry (SWV) at a mercury film‐coated glassy carbon (GC) electrode. At pH=10 NH3‐NH4Cl buffer, a new cathodic peak was found at −0.360 V (vs.SCE) by addition of thiamine, and the peak current of SWV was linear with the concentration of thiamine in the range of 1×10−6 to 4×10−3 M. On the other hand, the SWV peak current of Cd2+ at −0.856 V linearly decreased with addition of ascorbic acid in the range of 6×10−6∼10−3 M. The effects of interference, such as citric acid, DL‐malic acid, and calcium panlothenate, on thiamine or ascorbic acid determination were investigated. This method was successfully applied to the determination of thiamine or in pharmaceutical preparation.
EFFECT OF SUPPLEMENTAL POTASSIUM (K+) ON GROWTH, PHYSIOLOGICAL AND BIOCHEMICAL ATTRIBUTES OF WHEAT GROWN UNDER SALINE CONDITIONS

Present experiment was conducted to assess the ameliorative effects of soil and foliar application of potash fertilizers, i.e., sulfate of potash (SOP) and muriate of potash (MOP) on five wheat cultivars (‘Sitta’, ‘Sehar’, ‘Bhakkar-2006’, ‘PFAU#VEE’, ‘S-24’), subjected to salt stress created by applying sodium chloride (NaCl; 10 dS m−1) to the growth medium. Different treatments of potash fertilizers used included: control, SOP (100 kg ha−1) in soil, foliar spray of 1% solution of SOP, MOP (100 kg ha−1) in soil and foliar spray of 1% solution of MOP. Experiment was carried out in completely randomized design with three replications. Imposition of salt stress reduced growth, yield, and related yield attributes, photosynthetic attributes, ionic contents and biochemical activities in all wheat cultivars. However, application of potash fertilizers in soil as well as in foliar spray counteracted the adverse effects of salt stress on all wheat cultivars and the application of SOP in soil and as a foliar spray proved to be more effective in inducing salt stress tolerance. No adverse effect of chloride on plant growth was observed. Among the cultivars, ‘S-24’ and ‘Sehar’ showed the maximum growth, yield and biochemical contents and thus could be used in future for obtaining better yield under saline conditions.