Miracle-dz/UniFAR-FTUs huggingface dataset:
Modeling and Measurement of Glass Transition Temperatures of Energetic and Inert Systems

In this article, measurements of glass transition temperature (Tg) changes of two energetic material blend systems were carried out using the differential scanning calorimetry (DSC) technique. On one hand, experimental Tg values were compared to those predicted by the additivity model, Fox and Pochan equations, and, on other hand, to atomistic molecular dynamics simulation results performed in this work. The two blend systems studied were both composed of a polymer, either the inert hydroxyl-terminated polybutadiene (HTPB) or the energetic polyglycidylazide (GAP), and smaller molecules, which acted as plasticizers, dioctyl adipate (DOA), or glycidylazide oligomers (Gp1). Modeling results show deviations from experimental data, which varied from 5 to 20 K over an absolute scale for pure components and blends. A good fit was found when predicting the effect of adding smaller molecules to HTPB. Simulations were particularly useful for the blend in which the glass transition temperature of one component, DOA, was not experimentally measurable, due to the high crystallinity of the small DOA molecule. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers.
Effects of Relative Humidity on Ozone and Secondary Organic Aerosol Formation from the Photooxidation of Benzene and Ethylbenzene

The formation of ozone and secondary organic aerosol (SOA) from benzene–NO x and ethylbenzene–NOx irradiations was investigated under different levels of relative humidity (RH) in a smog chamber. In benzene and ethylbenzene irradiations, the intensity of the bands of O‒H, C˭O, C‒O, and C‒OH from SOA samples all greatly increased with increasing RH. The major substances in SOA were determined to be carboxylic acids and glyoxal hydrates. It was also found that SOA contained aromatic products, and NO2- and ONO2-containing products. The results show that the increase in RH can greatly reduce the maximum O3 by the transfer of NO2- and ONO2-containing products into the particle phase. During the process of evaporation, the lost substances from the collected SOA have similar structures for both benzene and ethylbenzene. This demonstrates that ethyl-containing substances are very stable and difficult to evaporate. For benzene, some of glyoxal hydrates were left to form C‒O‒C- and C˭O-containing species like hemiacetal and acetal after evaporation, whereas for ethylbenzene, glyoxal favored cross reactions with ethylglyoxal during evaporation. Only a few species in SOA were released into the gas phase during evaporation while a large part of SOA remained, which is mainly composed of carboxylic acid. It is concluded that the aqueous radical reactions and the hydration from glyoxal can be enhanced under high RH conditions, which can irreversibly enhance the formation of SOA from both benzene and ethylbenzene. Copyright 2014 American Association for Aerosol Research
In vitro antiplatelet activity of silver nanoparticles synthesized using the microorganism Gluconobacter roseus: an AFM-based study

In this work, the synthesis of silver nanoparticles (AgNPs) from Gluconobacter roseus, their characterization and their antiplatelet activity has been described. Gluconobacter roseus, an electrochemically active bacterium, mediates the synthesis of silver nanoparticles in the solution containing AgNO3 as a precursor and sorbitol as an electron donor. The bacteria act as a whole-cell biocatalyst to oxidise the sorbitol substrate and produce electrons for the reduction of Ag+ ions. The detailed characterization of the purified nanoparticles was carried out using UV-vis spectroscopy, EDAX (Energy dispersive X-ray spectroscopy), Transmission Electron Microscopy (TEM) and Fourier Transform Infrared Spectroscopy (FTIR). From the analysis of the UV-vis spectroscopy and EDAX, the formation of AgNPs was confirmed. The average particle size was found out to be 10 nm using TEM. FTIR results indicated the presence of amide groups which might be involved in stabilizing the nanoparticles. After the detailed characterization, the antiplatelet activity of synthesized AgNPs was investigated using aggregation assay and spreading studies. The AgNPs showed dose-dependent antiplatelet activity against ADP-induced activation of the blood platelets. AgNPs significantly decreased the aggregation by up to 87%. Spreading studies were made using Atomic Force Microscopy (AFM). Lactate dehydrogenase (LDH) assay was performed to check the cytotoxicity of the nanoparticles and interestingly the nanoparticles do not confer toxicity to the platelets. AFM is presented as a new method to assess the relative amounts of antiplatelet activity.
Development and chemical and sensory characterization of pumpkin seed flour-based cereal bars

Pumpkin (Cucurbita maxima), popularly known as squash, is a widely grown vegetable in Brazil. In this study, pumpkin seed flours (PSF) with different granulometries were used: PSF 1 (medium granulometry) and PSF 2 (coarse granulometry) in the preparation of cereal bars (CB) with different combinations with brown oats. Five formulations were prepared: CB-1 (control - 25% brown oats and 0% PSF); CB-2 (12.5% PSF 1 and 12.5% brown oats); CB-3 (25% PSF 1 and 0% brown oats); CB-4 (12.5% PSF 2 and 12.5% brown oats); and CB-5 (25% PSF 2 and 0% brown oats). The acceptance test results were analyzed in a conventional preference mapping which indicated that the bars CB-2 and CB-5 received mostly the maximum hedonistic score. With the objective of developing a cereal bar replacing oats with PSF, the bars CB-2 and CB-5 were compared to the conventional bar CB-1. The cereal bars CB-2 and CB-5 showed an increase in crude protein (87.5% and 62.5%) and in dietary fiber (77% and 44%), respectively. These results allowed the classification of CB-2 and CB-5 as fiber sources; they can, therefore, be classified as light products according to the Brazilian legislation.
The decomposition of turfgrass clippings is fast at high air humidity and moderate temperature

Abstract In grassland areas where herbage production has no economic value, the cut grass is often left on the sward surface where its decomposition is influenced by weather conditions. Although the influence of temperature and humidity on decomposition has been investigated under controlled lab conditions, experimentation has generally been under ideal moisture conditions that have not tested the combinations of climatic limitations that might occur in the field. The decomposition of mown turfgrass clippings deposited at different times of vegetation period was studied in situ using nylon bags during the first 8 weeks after deposition to investigate the effect of weather conditions (the air temperature, relative humidity, precipitation) on decomposition. Decomposition is the highest in the case of high air humidity and temperature of 10°C. Limiting factors for decomposition at temperatures above 10°C is the air humidity and below 10°C the air temperature. The general tendency was that the rate of decomposition increased with increasing air temperature up to 10°C, but with further increases of air temperature the decomposition rate slowed down. Relative air humidity had a variable impact (at the beginning of the decomposition process (weeks 1–2) the influence was negative, during weeks 3–8 of the decomposition process the effect was positive), and hence had no generalized relationship with decomposition over the studied decomposition period (weeks 1–8). The most significant influence of weather conditions on the decomposition rate was recorded directly after cutting. If the cutting was done during hot weather conditions, the material was drying fast and therefore decomposed slowly. Our results indicate that for fast decomposition of clippings it is important to maintain the freshness of material. Lower decomposition rates occurred during conditions of hot and dry weather, and also cooler (temperature near to 0°C) weather, and can be compensated as soon as favourable weather arrives.
Catalytic Asymmetric Inverse-Electron-Demand (IED) [4+2] Cycloaddition of Salicylaldimines: Preparation of Optically Active 4-Aminobenzopyran Derivatives

The catalytic asymmetric inverse-electron-demand (IED) [4+2] cycloaddition of various salicylaldehyde-derived N-arylimines with electron-rich alkenes in the presence of chiral BINOL-derived phosphoric acid catalysts has been studied with the aim of obtaining optically active 4-aminobenzopyran derivatives. Dienophiles such as 2,3-dihydro-2H-furan, benzyl N-vinylcarbamate and 2-vinylindole have been employed.
Study of PE and iPP orientations on the surface of carbon nanotubes by using molecular dynamic simulations

In this study, the early stage of interfacial crystallisation behaviour of low molecular weight polyethylene (PE) and isotactic polypropylene (iPP) oligomer on the surface of carbon nanotubes (CNTs) with different diameters, chiralities and topography structures was studied using MD simulations. We started to simulate the effect of CNTs chirality and diameter on PE molecular chain orientation, and then the effect of CNTs topography structure on PE and iPP molecular chain orientation was investigated. Finally, some experiments were carried out to prove the simulated results. Our study shows that for CNTs with a diameter comparable with the radius of gyration (Rg) of a polymer chain, an easy orientation of PE chains along CNTs axis is observed for all the systems of the CNTs with different chiralities due to a geometric confinement effect. For CNTs with a much larger diameter, multiple orientation of PE chains is induced on its surface due to the lattice matching between graphite lattice and PE molecular chains. In this case, the chirality of CNTs dominates the orientation of graphite lattice, which determines the orientation of PE chains arrangement on CNTs surface. More importantly, it was found that the groove structure formed by CNT bundles is very useful for the stabilisation of polymer chain, and thus facilitates the orientation of molecular chain along the long axis of CNTs. As a result, a novel nanohybrid shish–kebab (NHSK) structure with CNTs acting as central shish while polymer lamellae as kebab can be successfully obtained for both PE with zigzag conformation and iPP with helical conformation. This simulation result was well supported by the experimental observation. Our study could provide not only a deep understanding of the origin of the polymer chain orientation on CNTs surface but also the guidance for the preparation of polymer/CNTs nanocomposites with novel NHSK structure.
Semi-Supervised Implicit Neural Representation for Polarimetric ISAR Image Super-Resolution

Compared with the optical imaging system, polarimetric inverse synthetic aperture radar (ISAR) can work all-day and all-weather, which plays an important role in space surveillance. However, high-resolution (HR) ISAR images usually require large bandwidth and coherent integration angle, which is limited by the equipment’s physical conditions. In this vein, the super-resolution (SR) of ISAR images is of vital importance. At present, supervised learning methods are often used in image SR of computer vision. By constructing low-resolution (LR) and HR data pairs, the neural network can learn the mapping relationship between them. However, the low-frequency information in LR image data is less considered. In addition, to obtain different scales of SR reconstruction results, multiple network training repetitions are usually needed, which consumes time and hardware resources. Based on the idea of implicit neural representation, this letter constructs an implicit neural network representation framework for polarimetric ISAR image SR, which can obtain multiscale SR results through one training. A semi-supervised module is also constructed to make the network have the ability of supervised and unsupervised learning, which is conducive to mine and make better use of LR images. A polarimetric ISAR image SR dataset is constructed for satellite targets, while four indexes are adopted for quantitative evaluation in global and local aspects. Experiments demonstrate that the proposed approach achieves better SR performance, where the peak signal-to-noise ratio (PSNR) index can be increased at least by 0.93 dB.
Higher order regularization for model based data decompression / vorgelegt von Martin Holler

This thesis deals with the development, analysis and application of a mathematical model for image reconstruction. The model is realized by minimizing the sum of two convex functionals, one ensuring data fidelity and the other being a regularization term. The novelty of the considered approach lies both in the general definition of the data term as well as the application of the non-standard Total Generalized Variation (TGV) functional for regularization in this context. The main part of the work is the extension of theory for the TGV functional, the definition and analysis of the general reconstruction model and its application to imaging tasks. In particular, existence of a solution and optimality conditions for the resulting minimization problem are obtained for a setting that covers diverse applications: Suitable problem formulations for JPEG and JPEG 2000 decompression as well as wavelet based zooming are defined in function space setting and numerical solution schemes for the discretized problems are developed.
Synthesis, Characterization, and Thermal and Explosive Properties of Alkali Metal Salts of 5,7-Diamino-4,6-Dinitrobenzofuroxan (CL-14)

Potassium, rubidium, and cesium salts of 5,7-diamino-4,6-dinitrobenzofuroxan (CL-14) have been prepared by reacting sodium salt of 5,7-diamino-4,6-dinitrobenzofuroxan with alkali metal nitrate in an aqueous medium. The structure of the compounds was unequivocally confirmed by spectra data, elemental analyses, and estimation of metal content. Further, the compounds have been evaluated for explosive and thermal properties and found more suitable as compared to alkali metal salts of 4,6-dinitrobenzofuroxan (DNBF).
Upgrading of Methane under Homogeneous Thermal Conditions: An Environmental and Economic Imperative

After a brief outline of current estimates of the amount of methane annually injected into the atmosphere from fossil sources, we list various techniques that have been proposed and tested for converting methane to higher molecular weight hydrocarbons and alcohol to facilitate transport to locations where these chemicals could be utilized either directly to generate power or as feed stock for further processing. We propose a thermal conversion under homogeneous conditions that appears attractive, based on an extensive computer analysis of the kinetic mechanisms that control pyrolysis of methane when mixed with selected radical generators, at relatively modest temperatures (∼900 °C), that initiate C−H bond fission during the early stages of pyrolysis. Product distributions were computed to illustrate theoretically attainable temperature and time dependent levels of conversion. Therein, two key assumptions were made: “kinetic trapping” of radical-initiated products can be achieved; no solid deposits were g.
Growth of Diamond Thin Films by dc Plasma Chemical Vapor Deposition and Characteristics of the Plasma

Diamond thin films have been formed by dc plasma chemical vapor deposition from a gaseous mixture of methane and hydrogen (gas ratio (CH4/H2); 2/100, total gas pressure; 2.66×104 Pa) with a growth rate of ∼20 µm/h. During the course of diamond growth, characteristics of the plasma were measured by the Langmuir single probe method and also by emission spectrometry. From the characterization of the plasma, it was found that the degree of ionization was rather low (∼10-7), and the statistical temperature of hydrogen gas was ∼5×103 K. By a thermodynamic investigation at the gas temperature around 5×103 K, it was revealed that the source gases (H2 and CH4) of over 99% are decomposed to neutral atomic hydrogen and atomic carbon.
Headspace Volatiles of Vicia sativa L. (Leguminoseae) by Solid-Phase Microextraction and Gas Chromatography/Mass Spectrometry

Abstract The leaf volatile constituents of Vicia sativa L. have been studied using Headspace Solid-Phase Microextraction and Gas Chromatography/Mass Spectrometry (HS/SPME-GC/MS) and GC-FID. Forty-three components, aliphatic hydrocarbons, alcohols, aldehydes and ketones, aromatic aldehydes, esters and alcohols, monoterpenes and sesquiterpenes were fully characterized by mass spectra, linear retention indices, and injection of standards; the average composition as single components and classes of substances is reported. Leaf volatiles in Vicia sativa L. were characterized by a high amount of aldehydes, with the (Z)-2-hexenal (the typical leaf aldehyde) the main component.
Quantitative measurement of surface potential and amount of charging on insulator surface under electron beam irradiation

Surface potential and the amount of charging on an insulator surface under electron beam irradiation have been quantitatively measured. For these measurements, a special sample holder was developed. The surface potential was measured using a secondary electron method. The measurement of the surface potential revealed that the sample behaves as a resistor, enabling the present technique to be applied for mapping microarea resistance. The results of measuring the amount of charging revealed that the amounts of charging obtained with different beam currents are the same in spite of different surface potentials. This strongly suggests that the charging phenomenon depends on the distribution of the charge trapping sites.
Scanning tunneling microscopy

A scanning tunneling microscope (STM) can provide atomic‐resolution images of samples in ultra‐high vacuum, moderate vacuum, gases including air at atmospheric pressure, and liquids including oil, water, liquid nitrogen, and even conductive solutions. This review contains images of single‐crystal metals, metal films, both elemental and compound semiconductors, superconductors, layered materials, adsorbed atoms, and even DNA. A discussion of results on lithography leads into speculations on a bright future in which STMs may not only observe, but also manipulate surfaces, right down to the atomic level.
Tracing the Efficiency of Secondary Treatment Systems

A technique for mapping the three-dimensional performance of secondary treatment systems and for studying the behavior of specific compounds in-situ is described. [ 14 C]Oleic acid was added to samples collected from various locations in the system. Each mixture was placed in a vial capped at both ends with semipermeable membranes, returned to its original position in the lagoon, and then retrieved after 1 day. The amount of radioactivity remaining, after correction for leakage and nonbiological losses, is a measure of biological activity. The approach revealed that water-column biodegradation was only one of many pathways for oleic acid removal, with sorption to solids also being important and, perhaps, dominant. Furthermore, it rationalized performance differences between an AST (activated sludge treatment) system and an ASB (aerated stabilization basin).
Chemical model to explain asphalt binder and asphalt–aggregate interface behaviors

The behavior of asphalt mixtures is very complicated due to structural configuration and interfacial friction of aggregates as well as chemical and rheological reactions of the asphalt binder itself or with the aggregates. Furthermore, this complex response is more complicated under various loads, temperatures, and other environmental factors. To control the complex responses and reduce the complex factors, a DSR moisture damage test using small rock disks was developed. This paper focuses on the more fundamental concepts to explain asphalt and asphalt–aggregate bond behavior exhibited under the newly-developed DSR moisture damage test. The traditional model of asphalt structure is based on the theory of colloid and surface chemistry. Although this traditional model can explain many physical phenomena of asphalt structure, it cannot explain all the asphalt behaviors, such as steric hardening. Therefore, more general, but fundamental concepts may be required to attain insight of the material. As one of the.
Formation of solid sulfur by decomposition of carbon disulfide in the oxygen-lean cold plasma environment

In general, the conventional thermal processes for treating toxic carbon disulfide (CS2) gas were by the oxidation of sulfur on CS2 to form SO2. However, this study demonstrated that by using a radio-frequency cold plasma reactor in the oxygen-lean condition (O2/CS2 = R = 0.6) at the applied power of 90 W, the decomposition fraction of CS2 could reach 88.2%, and there was 76.9% of input sulfur mass from CS2 converted into solid sulfur with the purity of 99.2%. No solid sulfur was observed for the no-oxygen (R = 0) or oxygen-rich conditions (R = 3.0). Hence, the results of this study provided an approach for sulfur recovery to reduce the emissions of both CS2 and SO2. In addition, the reaction mechanisms for the decomposition of CS2 and for the formation of gaseous SO2, CO, CO2, and OCS in the CS2/O2/Ar plasma were also built up and discussed.
Failure of classical elasticity in auxetic foams

Poisson's ratio, ν, was measured for four materials, a rubbery polymer, a conventional soft foam, and two auxetic foams. We find that for the first two materials, having ν ≥ 0.2, the experimental determinations of Poisson's ratio are in good agreement with values calculated from the shear and tensile moduli using the equations of classical elasticity. However, for the two auxetic materials (ν < 0), the equations of classical elasticity give values significantly different from the measured ν. We offer an interpretation of these results based on a recently published analysis of the bounds on Poisson's ratio for classical elasticity to be applicable.
Membrane engineering for process intensification : a perspective

Pushed by the increasing demand for materials, energy and products, chemical engineering today faces a crucial challenge: to support a sustainable industrial growth. One possible solution is process intensification (PI), the innovative design strategy aiming to improve manufacturing and processing by decreasing the equipment size/productivity ratio, energy consumption and waste production using innovative technical solutions. Membrane processes meet the requirements of PI because they have potential to replace conventional energy-intensive techniques, to accomplish the selective and efficient transport of specific components, and to improve the performance of reactive processes. Here, we identify the most interesting aspects of membrane engineering in some strategic industrial sectors. The opportunity to integrate conventional membrane units with innovative systems in order to exploit the potential advantages coming from their synergic applications is also emphasized. Copyright © 2007 Society of Chemical Industry
Collision Theory of Relaxation Processes

Expressions for the NMR relaxation times T1 and T2 as well as for the chemical shift σ are given in terms of the binary transition operator. These are obtained by solving a Boltzmann equation valid for a dilute monatomic gas. Crude estimates of the anisotropic part of the transition operator and of T1 are obtained for dipolar and spin—rotation interactions. These agree in magnitude with other estimates of these quantities.