Miracle-dz/UniFAR-FTUs huggingface dataset:
Mechanisms of thermal degradation of polystyrene, polymethacrylonitrile, and their copolymers on flash pyrolysis

The mechanism of thermal degradation of homopolymers of styrene (St) and methacrylonitrile (MAN) and their copolymers was investigated theoretically and experimentally by the pyrolysis gas chromatography using a Curie-point pyrolyzer. Poly(St-co-MAN)s generate dimers and trimers as well as monomers by flash pyrolysis. Parameter α was proposed to account for the competition between the back-biting reaction and depolymerization. The back-biting parameter α is defined as the ratio of rate constants, α = k bb /k dp , where k bb is the rate constant for the back-biting reaction and k dp is that for depolymerization. The back-biting process is followed by β-scission, where dimer and trimer are generated, and directly correlated with the C-H bond dissociation energies in the polymer chain. Using the back-biting parameter α, where 1/α is equal to the zip length n in depolymerization, the boundary effect for the difference of monomer yields from the homopolymers of St and MAN and their copolymers is well explained. The calculated values of boundary effect parameters, β St and β MAN , agreed well with the experimental results. It was found that thermal degradation mechanisms of homo- and copolymers of vinyl compounds can be analyzed comprehensively using the back-biting parameter α and the boundary effect parameter β.
Safe Trade – A Stock Recommender using Machine Learning Algorithms

The business and financial sector currently controls the majority of the global economy, and stock market trading is a key activity there. The project uses Google’s Tensorflow’s Keras API to create LSTM, training the algorithm on historical data to forecast stock prices. We focused on forecasting the trend in a stock’s value over the subsequent 20 days after the prediction day. It is a method where one attempts to foresee the future worth of the company’s present stocks to prevent loss or maybe make a profit. With the use of several quantities that will be discussed later in this report, this study will show how machine learning can be used to anticipate the same. To create somewhat accurate forecasts, we suggest a machine learning algorithm that will be taught using various datasets of certain firms that were available in the past. Shares market forecasting is a method for estimating the future value of a company’s stock or another financial asset traded on an exchange. The only goal of stock market forecasting is a measurable substantial gain, along with, of course, avoiding large losses. Given that the efficient market hypothesis states that these forecasts cannot be produced with the data that is now available, some people may question the veracity of the findings of these predictions and conclude that they are fundamentally unexpected. However, a variety of instruments and technology make it possible to learn about future trends, which generates real income. The suggested approach detects frames with 85.5% accuracy.
Comparison of the Zeta Potential with the Diffuse Layer Potential from Charge Titration

The hypernetted chain (HNC) theory is used to compare charge titration and zeta potential data for several colloids. It is found that the HNC diffuse layer potential is closer to the zeta potential than that calculated with the traditional Poisson−Boltzmann (PB) approximation, and hence the amount of counterion binding required to bring the two into conformity is reduced. Further improvement is obtained by using an effective PB diffuse layer potential, calculated from both the numerical HNC theory and the analytic extended PB approximation. The rationale for using the effective PB potential is that the conversion from the measured electrophoretic mobility to the zeta potential invokes the PB approximation. In the case of silver iodide quantitative agreement is obtained without any fitting parameters, which confirms that no counterion binding occurs. For the metal oxides analyzed (titanium dioxide, aluminum oxide, and silicon dioxide) the two measurements can only be reconciled by postulating counterion bi.
Molecular Basis for the Dynamic Strength of the Integrin α4β1/VCAM-1 Interaction

Intercellular adhesion mediated by integrin α4β1 and vascular cell adhesion molecule-1 (VCAM-1) plays a crucial role in both the rolling and firm attachment of leukocytes onto the vascular endothelium. Essential to the α4β1/VCAM-1 interaction is its mechanical strength that allows the complex to resist the large shear forces imposed by the bloodstream. Herein we employed single-molecule dynamic force spectroscopy to investigate the dynamic strength of the α4β1/VCAM-1 complex. Our force measurements revealed that the dissociation of the α4β1/VCAM-1 complex involves overcoming at least two activation potential barriers: a steep inner barrier and a more elevated outer barrier. The inner barrier grants the complex the tensile strength to withstand large pulling forces (>50 pN) and was attributed to the ionic interaction between the chelated Mg2+ ion at the N-terminal A-domain of the β1 subunit of α4β1 and the carboxyl group of Asp-40 of VCAM-1 through the use of site-directed mutations. In general, additional mutations within the C-D loop of domain 1 of VCAM-1 suppressed both inner and outer barriers of the α4β1/VCAM-1 complex, while a mutation at Asp-143 of domain 2 of VCAM-1 resulted in the suppression of the outer barrier, but not the inner barrier. In contrast, the outer barrier of α4β1/VCAM-1 complex was stabilized by integrin activation. Together, these findings provide a molecular explanation for the functionally relevant kinetic properties of the α4β1/VCAM-1 interaction.
Wafer thickness optimization for silicon solar cells of heterogeneous material quality

In this Letter, we introduce a method of calculating the optimal wafer thickness for silicon solar cells with multicrystalline bulk material. The optimal thickness depends on the relation of bulk recombination to surface recombination and the light trapping. For multicrystalline silicon bulk recombination strongly varies laterally and with injection level, which complicates the calculations. A thickness optimization using the “Efficiency Limiting Bulk Recombination Analysis” (ELBA) takes all these effects correctly into account. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Improving the efficiency of CdS/CdTe solar cells by varying the thiourea/CdCl2 ratio in the CdS chemical bath

In this work, the influence of the properties of CdS thin films grown by chemical bath deposition upon the characteristics of CdS/CdTe solar cells, when varying the thiourea concentrations in the CdS bath solution, is studied. The important solar cell parameters such as short circuit current (Jsc), open circuit voltage (Voc), fill factor (FF) and efficiency (η) were measured and it was noted that they improve for thiourea/CdCl2 ratios (in the CdS deposition solution) up to 5, and drop for higher ratios in the range investigated. In addition, the ideal diode factor (n), saturation current (Jo) and series resistence (Rs) were studied under illumination and dark conditions. The results could be related to several factors, among them, the photoconductivity properties of the layers and the change of the CdS1−xTex layer at the CdS–CdTe interface.
Preparation and properties of alginate superabsorbent filament fibers crosslinked with glutaraldehyde

Superabsorbent filament fibers based on sodium alginate were prepared using glutaraldehyde as a crosslinking agent. Alginate was extruded into an aqueous hydrochloric acid coagulation bath to form continuous alginic acid gel fibers via a wet-spinning method. The alginic acid gel fibers were dehydrated by exchanging water with dioxane, crosslinked, then neutralized for better absorbency. Crosslinked alginate filaments exhibited a high saline solution and synthetic urine absorbencies, maintaining the integrity of the fiber structure. Maximum synthetic urine absorbency was obtained with the fiber crosslinked at a lower glutaraldehyde concentration compared with that required for maximum saline solution absorbency. This appears to be due to the crosslinking effect of calcium ions in the synthetic urine solution being absorbed. Strain and tenacity of the crosslinked alginate fibers decreased with an increasing amount of glutaraldehyde used in the crosslinking reaction. The decrease in tenacity was not significant while the strain showed an extensive decrease. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1797–1804, 2000
Chemical Fractionation and Phytoavailability of Heavy Metals in a Soil Amended with Metal Salts or Metal-Spiked Poultry Manure

Chemical fractionation patterns and plant tissue concentrations were used to assess nickel, copper, zinc, cadmium, and lead phytoavailability to maize in a soil amended with metal salts or poultry manure. A sandy loam was treated with 80–400 mg kg−1 doses of a quinternary mixture of the metal nitrates either directly or as spiked poultry manure. The European Communities Bureau of Reference sequential extraction procedure partitioned the metals among three operationally defined pools in the soil. Metal mobilities were lower in the poultry manure–amended than the metal salt–treated soil, indicating the manure's ability to fix the metals in soil. Pot experiments revealed high metal transferabilities with no apparent phytotoxic symptoms in maize at the doses applied, suggesting some degree of tolerance to the metals. Heavy-metal concentrations in maize increased linearly with metal doses in metal salt–treated soil, but were less phytoavailable in soil amended with poultry manure. Heavy-metal concentrations in maize were reasonably predicted from soil parameters using stepwise multivariate regression models. The findings are useful in the assessment and remediation of heavy metal–contaminated soils.
Stochastic Dynamics Simulations of Macromolecular Diffusion in a Model of the Cytoplasm of Escherichia coli

Stochastic dynamics simulations have been performed to investigate macromolecular diffusion in the cytoplasm of the bacterium Escherichia coli. The cytoplasm was modeled as a polydisperse mixture of three different types of spherical particles representing ribosomes, proteins, and tRNA molecules at their physiological concentrations. The interactions between the particles consisted of short-range Lennard-Jones and long-range electrostatic terms. A number of properties, including the pair distributions functions, the static structure factor, and the long-time self-diffusion coefficients, were obtained for various model systems differing from each other by the size of the charges on the particles. The effect of macromolecular crowding on these properties is examined, and their implication for the dynamics of macromolecules within living cells is discussed.
Corrections to the HNC equation for associating electrolytes

The accuracy of the HNC approximation and modifications based on a simple approximation for the sum of bridge graphs has been studied for a charged soft sphere model for dilute aqueous 2‐2 electrolytes. The accuracy is judged based on extensive Monte Carlo (MC) simulation for three representative concentrations: 0.005, 0.0625, and 0.2 M. The MC simulations find monotonically increasing like‐charge correlation functions in agreement with the modified HNC results but in contrast with the HNC prediction of a local maximum at low concentration. Nevertheless, HNC provides the best overall quantitative match with MC except at very low concentration; at 5 mM the modifications are a significant improvement. For unlike charge correlations, there is good agreement among all methods; at the ionic contact peak, however, HNC underestimates the peak height and the modifications provide improved accuracy.
The Innovation Efficiency In Central And Eastern Europe – An Input-Output Comparative Analysis Between Czech Republic, Hungary, Poland And Romania

The aim of this paper is to investigate the innovation efficiency in Central and Eastern Europe by performing an input-output approach using Data Envelopment Analysis (DEA). R&D government spending and total R&D personnel stand for inputs and patent applications and high-tech exports stand for innovation outputs. We performed a comparative analysis between Czech Republic, Hungary, Poland and Romania using a 10 year-time span (2007-2016). We demonstrated that over time the innovation efficiency has improved (both regarding technical efficiency and scale efficiency) in all the four countries under scrutiny. Moreover, our research showed that the most efficient country was Hungary which balanced properly between the efforts of supporting innovation and its benefits due to reaping its positive effects in terms of high-tech exports and patent creation.
Characterization of the conical intersection of the visual pigment rhodopsin at the CASPT2//CASSCF/AMBER level of theory

The branching plane associated with the conical intersection controlling the photochemical Z → E isomerization reaction of rhodopsin has been mapped using a CASPT2//CASSCF/AMBER quantum mechanics–molecular mechanics method. The nature of the derivative coupling and gradient difference vectors spanning the branching plane has been investigated, showing that the conical intersection is not only associated with the isomerization process but also to a charge transfer along the retinal backbone. Using a simple Landau–Zener model, the paper discusses the possible effects of the documented conical intersection topologies on the efficiency of the reactive process. It is argued that the peculiar shape of the conical intersection favours decay at structures that are geometrically displaced towards the photoproduct bathorhodopsin.
An Extended Hückel Theory. I. Hydrocarbons

The Huckel theory, with an extended basis set consisting of 2s and 2p carbon and 1s hydrogen orbitals, with inclusion of overlap and all interactions, yields a good qualitative solution of most hydrocarbon conformational problems. Calculations have been performed within the same parametrization for nearly all simple saturated and unsaturated compounds, testing a variety of geometries for each. Barriers to internal rotation, ring conformations, and geometrical isomerism are among the topics treated. Consistent σ and π charge distributions and overlap populations are obtained for aromatics and their relative roles discussed. For alkanes and alkenes charge distributions are also presented. Failures include overemphasis on steric factors, which leads to some incorrect isomerization energies; also the failure to predict strain energies. It is stressed that the geometry of a molecule appears to be its most predictable quality.
CFD simulation of heat transfer in turbulent pipe flow

In the present work, the flow pattern in pipe flow has been simulated using a low-Reynolds-number k-e model. The model has been extended to predict the heat-transfer coefficient in regions of both high and low Prandtl number. The computational fluid dynamic (CFD) approach has been shown to be superior to the conventional semiempirical approach for high turbulent Prandtl numbers and in cases where the molecular properties such as diffusivity and viscosity steeply change in the vicinity of the wall.
Studies on Organic Fluorine Compounds. XLII. Synthesis and Reactions of Phenyltrifluoromethylacetylenes

Phenyltrifluoromethylacetylene (4a) was synthesized by the pyrolysis of triphenylphosphonium α-(trifluoroacetyl) benzylide (3a), which was easily derived from benzyl halide (1a). This method can be used for the synthesis of 4-substituted-phenyltrifluoromethylacetylenes (4). The 1, 3-dipolar reaction of 4 with diazomethane and phenyl azide proceeds readily to give trifluoromethylated pyrazoles and triazoles.
Tunable Microlenses Optically Recorded in Dye-Doped Liquid Crystals

We report on optically recorded microlenses in conventional liquid crystal cells doped with the azo-dye methyl-red. The focal length can be tuned electrically with low external voltage and changed in a wide range with just a small variation of the applied dc field. No patterned electrodes, built-in polymeric lens or patterned molecular reorientation are required. The effect underlying the proposed fabrication method is connected to the surface induced nonlinear effect (SINE) observed a few years ago in dye doped liquid crystals.
Magnetic order in silicate minerals (invited)

Silicates are the most common Earth materials. Many iron‐rich solid solution series order magnetically but ordering temperatures rarely exceed 100 K, even for the iron end‐members. Minerals with sheet and chain structures are discussed, with emphasis on the magnetic properties of greenalite, cronstedtite, biotite, and crocidolite determined by magnetization, susceptibility, and Mossbauer measurements and by magnetic neutron diffraction. The principal magnetic interactions in the ferrous minerals are ferromagnetic, due to near 90° Fe–O–Fe bond angles for edge‐sharing octahedral sites, yet all of them order antiferromagnetically as the ferromagnetic sheets or chains are coupled by relatively weak antiferromagnetic interactions. A spin flop transition occurring in fields of 1–15 kOe at 4.2 K is analyzed in terms of effective anisotropy and exchange fields. Magnetocrystalline anisotropy arises from the Fe2+ ion which is in an orbital singlet 5A1g, lz=0 ground state in an effectively trigonal crystal field. Th.
Effects of Composition and Matrix Polarity on Network Development in Organogels of Poly(ethylene glycol) and Dibenzylidene Sorbitol

Dibenzylidene sorbitol (DBS) is a low-molecular-weight organic molecule that can gel a variety of organic solvents and polymers by self-organizing into a three-dimensional nanofibrillar network through hydrogen-bonding and phenyl interactions. In this work, we investigate the composition dependence of such “organogels” prepared with poly(ethylene glycol) (PEG) and two PEG derivatives differing in methoxy end- group substitution, which serves to reduce matrix polarity. Transmission electron microscopy reveals that individual DBS nanofibrils measure from about 10 to 70 nm in diameter, with a primary nanofibrillar diameter of about 10 nm. Dynamic rheological measurements indicate that the rate by which the elastic modulus increases during gelation, the temperatures corresponding to gel formation and dissolution, and the magnitude of the elastic modulus are all sensitive to the DBS mass concentration (φ) and the matrix polarity. Hydroxy-end-capped PEG/DBS systems gel more slowly, but dissolve faster, than the.
Effect of the epoxy resin chemistry on the viscoelasticity of its cured product

Received 27 July 2007; accepted 3 November 2007DOI 10.1002/app.27740Published online 23 January 2008 in Wiley InterScience (www.interscience.wiley.com). ABSTRACT: A detailed study investigating the relationbetween the initial resin composition and mixing ratio onthe viscoelastic behavior was performed. The resin system,containing a difunctional aromatic epoxy (DER 332), wasmixed with three aliphatic amines containing functional-ities of 2, 3, and 4 in different stoichiometric mixing ratiosand was cured. For each of the cured mixtures, the visco-elastic master curve and corresponding shift factors weredetermined. Depending on the crosslink density, the visco-elastic curves shifted by about 12 decades with respect tothe frequency scale. This shift in the viscoelastic curve waspredicted by the combination of the Miller–Macoskotheory for crosslink density with a parameterized Havri-liak–Negami model for the master curve. A single set of9 parameters turned out to be sufﬁcient to describe allviscoelastic data.
Essential oil composition of Myrrhis odorata (L.) Scop. leaves grown in Lithuania and France

The chemical composition of essential oils of sweet cicely (Myrrhis odorata (L.) Scop. ) leaves from two geographic areas (Lithuania and France) were determined by gas chromatography/mass spectrometry (GC/MS). Comparatively slight differences were observed in the chemical composition of essential oils from both selected origins. The yield of essential oil varied from 0.4±0.02% in Lithuanian to 0.5±0.01% in French origin. In total twenty and twenty-six components were identified in the hydrodistilled oils of Lithuanian and French origin, respectively. The essential oils of both origins were found to be rich in E-anethole (48.1±1.4% and 50.7±1.1%), methyleugenol (14.3±0.5% and 13.1±0.4%), E-nerolidol (10.2±0.8% and 12.0±0.3%) and germacrene-D (5.0±0.1% and 4.3±0.3%).
Empleo del polietilenglicol y la zeolita para mejorar el valor nutritivo de Albizia lebbekoides en condiciones in vitro

En un diseno completamente aleatorizado, con cuatro repeticiones por tratamiento, se determino la produccion de gas in vitro, la cinetica de fermentacion y la degradabilidad aparente de la materia seca (MS) de la leguminosa Albizia lebbekoides (albizia), incubada sola o con polietilenglicol (PEG-6000), zeolita o ambos compuestos. La produccion de gas se comparo a las 6, 12, 24 y 48 h de incubacion. Se estimo la cinetica de fermentacion in vitro, segun el modelo exponencial Y= D*(1-Exp (-C*(Hora-L)) y la degradabilidad aparente a las 48 h de incubacion, por gravimetria. La produccion de gas in vitro difirio a las 12 (P 0.01), 24 y 48 h (P 0.001) entre los tratamientos con PEG (albizia con PEG y albizia con PEG y zeolita). No fue asi para los que no incluyeron PEG (albizia sola y albizia con zeolita). El incremento de la produccion de gas con PEG fue de 385 % a las 4 h de incubacion y a las 6 h fue mas moderado (213 %). Se redujo a medida que avanzo la fermentacion in vitro hasta las 48 h, en que fue de 146 %. La cinetica de fermentacion de la leguminosa mostro que los tratamientos con zeolita incrementaron ligeramente la velocidad de produccion de gas (C). Los tratamientos en que se inactivaban los taninos con PEG disminuyeron la fase Lag (L) e incrementaron el potencial de produccion de gas. Se concluye que la zeolita no influyo en la degradabilidad ruminal de albizia en condiciones in vitro, mientras que el empleo del PEG mejoro la produccion de gas y el potencial de fermentacion de la leguminosa. Ademas, redujo la fase Lag de la fermentacion in vitro.
A Universal System for Cough Detection in Domestic Acoustic Environments

Automated cough detection may provide valuable clinical information for monitoring a patient’s health condition. In this paper, we present a cough detection system that utilises an acoustic onset detector as a pre-processing step, aiming to detect impulsive patterns in the audio stream. In a subsequent step, discrimination of coughing events from other impulsive sounds is handled as a binary classification task. In contrast to existing works, the proposed cough discrimination models are trained and tested with heterogeneous data uploaded by different users to online audio repositories. In that way, our system achieves robust performance to a wide range of audio recording devices and to varying noise and/or reverberation conditions. Our evaluation results showed that a sensitivity in the order of 90% and a specificity in the order of 99% can be achieved in a domestic environment with the utilization of Long-Short-Term-Memory deep neural network architecture.