Miracle-dz/UniFAR-FTUs huggingface dataset:
Chemiluminescence detector for NO and NO/sub 2/

Chemiluminescence instruments for measuring NO in situ are known to have the high sensitivity that is needed to detect this important tropospheric molecule in remote regions of the earth's atmosphere. In this paper a combination NO and NO/sub 2/ detector is described that has a high sensitivity for both NO and NO/sub 2/, along with a high specificity for NO/sub 2/ detection.
Cure reaction of multi‐walled carbon nanotubes/diglycidyl ether of bisphenol A/2‐ethyl‐4‐methylimidazole (MWCNTs/DGEBA/EMI‐2,4) nanocomposites: effect of carboxylic functionalization of MWCNTs

BACKGROUND: The aim of this work was to study, using differential scanning calorimetry, the effect of carboxylic functionalization of multi-walled carbon nanotubes (MWCNTs) on the cure reaction of MWCNTs/diglycidyl ether of bisphenol A/2-ethyl-4-methylimidazole (MWCNTs/DGEBA/EMI-2,4) nanocomposites. This is important for the practical design, analysis and optimization of novel materials processing. RESULTS: Comparing the influence of non-functionalized MWCNTs and carboxyl-functionalized MWCNTs, it was found that, at the initial curing stage, both MWCNTs act as catalyst and COOH functionalization of MWCNTs has a catalytic effect on the curing process. Then, at the later curing stage, non-functionalized MWCNTs prevent the occurrence of vitrification, whereas COOH functionalization of MWCNTs promotes vitrification. Non-functionalized MWCNTs decrease the degree of curing, as evidenced by lower total heat of reaction and lower glass transition temperatures of nanocomposites compared to neat epoxy; however, COOH functionalization of MWCNTs increases the degree of curing. CONCLUSION: For the development of composites, COOH functionalization of MWCNTs could bring a positive influence to the composite process. Its acceleration of cure could help shorten pre-cure time or lower pre-treatment temperature, and its effect of promoting vitrification could help shorten post-cure time or lower post-treatment temperature. Copyright © 2009 Society of Chemical Industry
Modeling of the Structure of a Premixed n-Decane Flame

Abstract The chemical structure of a premixed n-decane/O2/N2 flame (equivalence ratio 1.7) stabilized at atmospheric pressure on a flat-flame burner has been computed with two reaction mechanisms. In the first one, the consumption of the fuel molecule is described in detail, The five different n-decyl radicals formed by H atom abstraction from the decane molecule were distinguished and their consumption reactions were considered in a systematic way. This mechanism comprises 78 species involved in 638 elementary reactions. Modeling with this detailed mechanism led to species mole fraction profiles in good agreement with the experimental results. The main. reaction paths for the formation of final and intermediate species have been identified with special emphasis on benzene formation. The second mechanism was derived from the first one by successively removing an increasing number of n-decyl radicals. For most species, it is possible to maintain the reliability of the model with only one n-decyl radical in.
RAM-Net: A Residual Attention MobileNet to Detect COVID-19 Cases from Chest X-Ray Images

In the last century, we have passed two severe pandemics; the 1957 influenza (Asian flu) pandemic and the 1918 influenza (Spanish flu) pandemic with a high fatality rate. In the last few months, we have been again facing a new epidemic (COVID-19), which is a frighteningly high-risk disease and is globally threatening human lives. Among all attempts and presented solutions to tackle the COVID-19, a publicly available dataset of radiological imaging using chest radiography, also called chest X-ray (CXR) images, could efficiently accelerate the detection process of patients infected with COVID-19 through presented abnormalities in their chest radiography images. In this study, we have proposed a deep neural network (DNN), namely RAM-Net, a new combination of MobileNet with Dilated Depthwise Separable Convolution (DDSC), Residual blocks, and Attention augmented convolution. The network has been learned and validated using the COVIDx dataset, one of the most popular public datasets comprising the chest X-ray (CXR) images. Using this model, we could accurately identify the positive cases of COVID-19 viral infection while a new suspicious chest X-ray image is shown to the network. Our network’s overall accuracy on the COVIDx test dataset was 95.33%, with a sensitivity and precision of 92% and 99% for COVID-19 cases, respectively, which are the highest results on the COVIDx dataset to date, to the best of our knowledge. Finally, we performed an audit on RAM-Net based on the Grad-CAM’s interpretation to demonstrate that our proposed architecture detects SARS-CoV-2 (COVID-19) viral infection by focusing on vital factors rather than relying on irrelevant information.
1-Alkyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane salts: a novel family of electrophilic fluorinating agents

Members of a new series of solid, easily handled, storable, transportable, commercially viable, site-selective electrophilic fluorinating agents of the +N–F class (tradenamed Selectfluor reagents) have been synthesized via direct fluorination of monoquaternary salts of 1,4-diazabicyclo[2.2. 2]octane.
Base sequence dependence of charge transport via short DNA bridges

Charge transfer in a donor – short bridge – acceptor system is studied within a simple model of a DNA molecule. A difference in transfer rates via two bridges containing similar bases though with opposite sequences is demonstrated. The result calls for experimental verification. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
INTEGRATED EXTRACTION AND ANAEROBIC DIGESTION PROCESS FOR RECOVERY OF NUTRACEUTICALS AND BIOGAS FROM POMEGRANATE MARC

Pomegranate marc (PM), a by-product of pomegranate juice processing, has not been effectively utilized. The objectives of this study were: (1) to determine the yields and properties of antioxidants (henceforth referring to total phenolics in terms of tannic acid equivalent) and oil extracted from various dry and wet constituents of PM, including peel, seeds, and mixture; and (2) to evaluate the anaerobic digestibility and biogas production potential of PM before and after antioxidant extraction (AE) and oil extraction (OE). Water and petroleum ether were used as solvents in the extraction of antioxidants and oil, respectively. The anaerobic digestion tests were conducted at 35°C ±2°C with a feedstock to microorganism ratio of 0.5 on volatile solid (VS) basis under two initial organic loadings of 3.0 and 5.0 g VS L -1 . According to the results, both dry and wet PM extracts had similar extraction efficiency and functionality. The wet PM extract had an antioxidant content of 23.0%, which corresponded to an antioxidant yield of 106 kg per ton of PM peel on dry basis (d.b.). The DPPH scavenging activities of antioxidants were 6.5 to 6.6 g g -1 (d.b.). The oil yield from the dry PM seeds was 138 kg ton -1 (d.b.). Compared to the low initial organic loading, the high initial organic loading improved methane content (55.1% to 67.5%) but not biogas yield. The extracted residuals of peel, seeds, and mixture had methane yields of 148, 183, and 161 mL g -1 VS, respectively, which were lower than that from raw PM. Because the integrated process of extraction followed by anaerobic digestion can produce high functional antioxidants and high-quality biogas and oil from the PM, it is recommended as a value-added utilization method for the by-product.
Antibacterial activity of methanolic fruit extract of Randia dumetorum Lamk.

The goal of this study was to determine the preliminary antibacterial activity of Methanolic extract of Randia dumetorum Lamk. (Xeromphis spinosa Thumb.) belonging to family Rubiaceae toward some phytopathogenic bacteria. The antibacterial activity of the extract was done on some standard and wild pathogenic bacterial strains such as Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Bacillus subtilis Escherichia coli and Salmonella typhi. The testing was done by the agar cup plate method using sterile top agar. Zone of inhibition of extract (50, 100 and 150 mg/ml) was compared with that of standard Amoxicillin (0.5 and 1 mg/ml) prepared in DMSO. The extract shows potential antibacterial properties comparable with that of standard amoxicillin against the organisms tested. The methanolic extract of R. dumetorum displayed a concentration related antibacterial activity. The results show that the inhibition of the bacterial growth was more pronounced on Escherichia coli as compared to the other tested organisms.
Investigating the microbial inactivation efficiency of a 25 L batch solar disinfection (SODIS) reactor enhanced with a compound parabolic collector (CPC) for household use

BACKGROUND: A simple point-of-use solar disinfection (SODIS) reactor was designed to treat 25 L of water and was constructed from a methacrylate tube placed along the linear focus of a compound parabolic concentrator (CPC) and mounted at 37° inclination. Experiments were carried out over a 7 month period by seeding a 10 6 CFU mL -1 concentration of Escherichia coli K-12 in 25 L of well water or turbid water to mimic field conditions and determine the microbial effectiveness of the reactor. RESULTS: During periods of strong sunlight, complete inactivation of bacteria occurred in under 6 h, even with water temperatures 50 °C. No regrowth of bacteria occurred within 24 h and 48 h following solar disinfection. The construction cost of this prototype reactor was approximately US$200 but with an expected lifetime of 10 years, the running cost of the reactor is expected to be US$0.002 L -1 . CONCLUSION: This study confirms that significant water disinfection can be achieved using a low cost CPC-enhanced 25 L batch SODIS reactor.
Increased Electron Concentration in InAs/AlGaSb Heterostructures Using a Si Planar Doped Ultrathin InAs Quantum Well

We demonstrate that the two-dimensional electron gas concentration in an InAs/AlGaSb heterostructure can be greatly increased by introducing a Si planar-doped ultrathin InAs quantum well (QW) sandwiched between AlSb barriers as an additional electron supplying layer in a well controlled fashion. With the Si planar-doped QW formed 8 nm below the channel layer, the sheet electron concentration increased up to 4.5×1012 cm-2 with an electron mobility of 4×104 cm2/ Vs at 77 K. Shubnikov-de Haas measurements revealed that only two subbands are occupied, even for heavily doped samples. The energy separation between the first and the second subbands is as large as 100 meV, indicating a strong electron confinement in the selectively doped InAs/AlGaSb heterostructures.
Efficiency of the SASS4 rapid bioassessment protocol in determining river health: a case study on the Mhlathuze River, KwaZulu-Natal, South Africa

The purpose of the study was to verify the ability of the South African Scoring System version 4 (SASS4), to assess the health of aquatic ecosystems. The macroinvertebrate community attributes of the Mhlathuze River (KwaZulu-Natal, South Africa) were studied by applying the SASS4 rapid bioassessment method. In testing the effect of spatial and temporal variability in community structure on SASS4 scores it was found that there was a stronger spatial than a temporal effect. It was determined that of the indices used in association with SASS4, the biotic indices (average score per taxon, total score and number of taxa) reflected changes in community structure, but the abiotic habitat quality index did not. It was found that qualitative family-level data provided an adequate classification of sites for use in routine biomonitoring. Ambiguous results were obtained with respect to the importance of measuring abundance during routine biomonitoring. No definite conclusion with respect to the ability of the SASS4 to reflect physical-chemical water quality changes could be drawn from the results obtained in this study. SASS4 was able to reflect the effect of the tidal push from the Mhlathuze Estuary, but this marine influence probably masked less pronounced effects exerted by the remainder of the physical-chemical variables that were investigated. WaterSA Vol.28(1) 2002: 13-22
THIN-LAYER CHROMATOGRAPHY WITH DENSITOMETRY FOR THE DETERMINATION OF DIFLOXACIN AND ITS PHOTODEGRADATION PRODUCTS. KINETIC EVALUATION OF THE DEGRADATION PROCESS AND IDENTIFICATION OF PHOTOPRODUCTS BY MASS SPECTROMETRY

TLC-densitometric method was developed for determination of difloxacin (DIF) in the presence its photodegradation products. Silica gel TLC F254 plates were used as the stationary phase and methylene chloride:methanol:2-propanol:ammonia 25% (4:4:5:2, v/v/v/v) as the mobile phase. The elaborated method meets the acceptance criteria for specificity, linearity, sensitivity, accuracy, and precision. The photodegradation process of DIF followed kinetics of the first order reaction for the substrate. Potential photodegradation products of DIF identified by UPLC-MS/MS are: 7-(2-aminoethylamino)-6-fluoro-1-(4-fluorophenyl)-4-oxo-1,4-dihydroquinoline-3-carboxylic acid, 7-amino-6-fluoro-1-(4-fluorophenyl)-4-oxo-1,4-dihydroquinoline-3-carboxylic acid, 6-fluoro-1-(4-fuorophenyl)-7-(3-hydroxypiperazin-1-yl)-4-oxo-1,4-dihydroquinoline-3-carboxylic acid, 6-fluoro-1-(4-fuorophenyl)-4-oxo-7-(piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylic acid.
On the determination of the emitter saturation current density from lifetime measurements of silicon devices

Contactless photoconductance measurements are commonly used to extract the emitter saturation current density (Joe) for crystalline silicon samples containing an emitter on the surface. We review the physics behind the analysis of Joe and compare the commonly used approximations with more generalised solutions using two‐dimensional device simulations. We quantify errors present in such approximations for different test conditions involving varying illumination conditions and surface properties in samples with the same emitter on both sides. The simulated Joe obtained from the dark hole current from the emitter into the bulk is nearly the same as the simulated Joe determined by photoconductance measurements of the rear diffusion. The simulated Joe at the front emitter is equivalent to that at the rear emitter only when the sample is subject to a nearly constant and flat generation profile. For illumination conditions including visible light, the simulated Joe at the front emitter is smaller than the simulated Joe at the rear emitter. Both Joe at the rear emitter and from the dark hole current in the emitter remain nearly constant over a wide range of base doping densities. The approximations used for the determination of Joe from photoconductance measurements make Joe dependent on the excess minority carrier density. Lifetime measurements demonstrate that, even in high‐quality silicon, Joe should be determined from the analytical solution as a function of excess minority carrier density including Shockley‐Read‐Hall recombination. Copyright © 2012 John Wiley & Sons, Ltd.
One‐Dimensional Modeling of Transport in Soils with Depth‐Dependent Dispersion, Sorption and Decay

Macroscopic spatial variations in advection velocity lead to an increase in dispersion with increasing travel distance or depth. In soils, this increase goes along with a decrease in decay and sorption of organic substances. We used three different one‐dimensional models that make different assumptions about the dispersion process to compare predicted leaching in a 1‐m‐deep soil profile with layers with different sorption and decay parameters. The first two convective–dispersive models assume that dispersion results from microscopic variations in solute particle velocities that are not correlated across soil layer boundaries. The third model, a stream tube model (STM), assumes that the particle velocity remains constant along its trajectory and is perfectly correlated in different layers. The three models were parameterized to predict the same inert tracer breakthrough curve (BTC) at 1‐m depth. The first convective–dispersive model assumes a constant dispersion coefficient (“homogeneous” convection–dispersion equation [CDE]). The second model uses different dispersion coefficients in the different layers (“layered” CDE) to predict the same inert tracer BTCs as the STM at the layer boundaries. Despite similar predictions of inert tracer BTCs, the models predicted different BTCs of reactive substances at 1‐m depth. The different predictions by the STM and layered CDE illustrate the importance of the correlation of solute particle velocities in different soil layers. They also point to a fundamental problem related to the use of a CDE with a depth‐dependent dispersion to mimic a dispersion process caused by macroscopic variations in particle velocities.
HYDROMETALLURGICAL PROCESSING OF GOLD-BEARING COPPER ENARGITE CONCENTRATES

Abstract This paper outlines the application of the industrially proven technologies of low pressure and temperature Nitrogen Species Catalyzed (NSC) pressure leaching and Alkaline Sulphide Leaching (ASL) for the recovery of copper and gold from enargite. Copper can be recovered as a cathode metal or as a clean concentrate suitable for smelting. Gold is recovered by smelting, conventional cyanidation or alkaline sulphide hydrometallurgy. Coupled with this is the effective precipitation and stabilization of arsenic as scorodite and ferrihydrite. Cet article souligne l’utilisation des technologies éprouvées industriellement de la lixiviation sous pression à basse pression et température de l’Espèce d’Azote Catalysée (NSC) et de la Lixiviation Alcaline de Sulfure (ASL) pour la récupération du cuivre et de l’or de l’énargite. On peut récupérer le cuivre comme métal de cathode ou comme concentré propre approprié à la fusion. L’or est récupéré par fusion, par cyanuration conventionnelle ou par hydrométallurgie de sulfure alcalin. Couplé à cela, il y a la précipitation efficace et la stabilisation de l’arsenic en scorodite et ferrihydrite
Étude des mécanismes cellulaires activés par l'Angiopoïétine-1 et le VEGF régulant la perméabilité et la migration endothéliales

L’angiogenese est la formation de nouveaux vaisseaux sanguins a partir d’un reseau vasculaire existant. C’est un phenomene essentiel pour des processus physiologiques et pathologiques. L’activation des cellules endotheliales est controlee par plusieurs facteurs de croissance. Le VEGF et son recepteur le VEGFR-2 ont ete prouves comme etant specifiques et critiques pour la formation des vaisseaux sanguins alors que Tie2, le recepteur auquel se lie l’Ang-1, est requis aussi bien dans le developpement vasculaire que dans l’angiogenese tumorale. Il est connu que l’activation de Tie2 est necessaire a la stabilisation finale de la vascularisation en inhibant la permeabilite vasculaire induite par le VEGFR-2. Nous avons premierement decouvert que le facteur de croissance pro-angiogenique, l’Ang-1 contrecarre les effets de permeabilite cellulaire induits par le VEGF en inhibant la production de NO dans les cellules endotheliales. Cet effet inhibiteur de Tie2 intervient directement au niveau de l’activite de l’enzyme eNOS. Suite a l’activation de Tie2 par l’Ang-1, eNOS devient fortement phosphoryle sur la Thr497 apres la phosphorylation et l’activation de la PKCζ. Nos resultats suggerent que l’inhibition, par Tie2, de la permeabilite vasculaire durant l’angiogenese serait due, en partie, a l’inhibition de la production de NO. Deuxiemement nous avons pu distinguer entre deux modes de migration cellulaire endotheliale induits par l’Ang-1 et le VEGF. A l’oppose du VEGF qui promeut une migration individuelle aleatoire, l’Ang-1 induit une migration collective directionnelle. Dans cette etude, nous avons identifie la β-catenine comme un nouveau partenaire moleculaire de la PKCζ. Cette association de la PKCζ a la β-catenine amene le complexe de polarite Par6-aPKC et le complexe des jonctions d’adherences cellulaires a interagir ensemble a deux localisations differentes au niveau de la cellule endotheliale. Au niveau des contacts intercellulaires, le complexe PKCζ/β-catenine maintien la cohesion et l’adhesion cellulaire necessaire pour le processus migratoire collectif. Ce complexe se retrouve aussi au niveau du front migratoire des cellules endotheliales afin d’assurer la directionalite et la persistance de la migration endotheliale en reponse a l’Ang-1. D’une maniere interessante, lors de l’inhibition de la PKCζ ou de la β-catenine on assiste a un changement du mode de migration en reponse a l’Ang-1 qui passe d’une migration directionnelle collective a une migration individuelle aleatoire. Ce dernier mode de migration est similaire a celui observe chez des cellules endotheliales exposees au VEGF. Ces resultats ont ete corrobores in vivo par une polarite et une adhesion defectueuses au cours de la vasculogenese chez le poisson zebre deficient en PKCζ. En resume, Ang-1/Tie2 module la signalisation et les reponses biologiques endotheliales declenchees par le VEGF/VEGFR-2. L’identification des mecanismes moleculaires en aval de ces deux recepteurs, Tie2 et VEGFR-2, et la comprehension des differentes voies de signalisation…
Investigation of Polystyrene-Poly(ethylene oxide) Block Copolymer Micelle Formation in Organic and Aqueous Solutions by Nonradiative Energy Transfer Experiments

Micelle formation in THF-methanol, 1,2-dichloroethane-methanol, THF-water, and water solutions by PS-PEO diblock copolymers was studied by the fluorescence spectroscopy. For this purpose, a series of PS-PEO copolymers was labeled by the phenanthrene or anthracene groups at the block junctions. The chromophore contents in copolymers were determined by the absorbance spectroscopy using suitable model compounds. When micelles were present, intramicellar nonradiative energy transfer could be observed. For the PS-PEO copolymer (M n =114 000, 93 weight % PEO) we find the onset of micelle formation in water in the range of 10×10 -3 g/L (9×10 -8 M)
Experimental studies and thermodynamic modelling of volatilities of uranium, plutonium, and americium from their oxides and from their oxides interacted with ash

The purpose of this study is to identify the types and amounts of volatile gaseous species of U, Pu, and Am that are produced in the combustion chamber offgases of mixed waste oxidation processors. Primary emphasis is on the Rocky Flats Plant Fluidized Bed Incinerator. Transpiration experiments have been carried out on U{sub 3}O{sub 8}(s), U{sub 3}O{sub 8} interacted with various ash materials, PuO{sub 2}(s), PuO{sub 2} interacted with ash materials, and a 3%PuO{sub 2}/0.06%AmO{sub 2}/ash material, all in the presence of steam and oxygen, and at temperatures in the vicinity of 1,300 K. UO{sub 3}(g) and UO{sub 2}(OH){sub 2}(g) have been identified as the uranium volatile species and thermodynamic data established for them. Pu and Am are found to have very low volatilities, and carryover of Pu and Am as fine dust particulates is found to dominate over vapor transport. The authors are able to set upper limits on Pu and Am volatilities. Very little lowering of U volatility is found for U{sub 3}O{sub 8} interacted with typical ashes. However, ashes high in Na{sub 2}O (6.4 wt %) or in CaO (25 wt %) showed about an order of magnitude reduction in U volatility. Thermodynamic modeling studies were carriedmore » out that show that for aluminosilicate ash materials, it is the presence of group I and group II oxides that reduces the activity of the actinide oxides. K{sub 2}O is the most effective followed by Na{sub 2}O and CaO for common ash constituents. A more major effect in actinide activity lowering could be achieved by adding excess group I or group II oxides to exceed their interaction with the ash and lead to direct formation of alkali or alkaline earth uranates, plutonates, and americates. « less