Miracle-dz/UniFAR-FTUs huggingface dataset:
New bis-quaternary ammonium and bis-imidazolium chloride wood preservatives

Abstract Bis-quaternary ammonium and bis-imidazolium chlorides, the compounds containing in their structure two symmetrical quaternary nitrogen atoms, were prepared and tested on wood destroying and sapstaining fungi. The effect of the position of quaternary nitrogen atoms upon fungicidal and surface properties was analysed. The antifungal activity of new bis-quaternary ammonium and bis-imidazolium chlorides against Coniophora puteana (Schum.:Fr.)Kr. , Trametes versicolor (L.:Fr.)Pilát and Aspergillus niger van Tieghem was much more pronounced than that of quaternary ammonium chlorides. The results confirm the correlation between surface activity and fungicidal activity. The adsorption of bisimidazolium chloride onto pine wood was influenced by pH of applied solutions and the initial solution concentration. With increasing pH of ammonium solution, the adsorption was much greater than in neutral or acidic solutions. Cation structure of the quaternary ammonium chloride exerted a strong influence on quantity of wood-adsorbed chemicals and resistance to water leaching.
On the structure of molybdenum diselenide and disulfide

The crystal structure of MoSe2 has been refined from single-crystal X-ray diffraction data. MoSe2 is isotypic with hexagonal MoS2 (C7 type); a = 3.289(1) A, c = 12.927(4) A, z(Se) = 0.6210(3). It is pointed out that the structure of MoS2 is incorrectly given in many books, although it had already been correctly reported by Dickinson and Pauling [4]. Corrected interatomic distances are given; the trigonal prism about Mo is almost regular. Zur Struktur von Molybdandiselenid und -disulfid Die Kristallstruktur von MoSe2 wurde aus Einkristall-Rontgenbeugungsdaten verfeinert. MoSe2 ist isotyp mit hexagonalem MoS2 (C7-Typ); a = 3,289(1) A, c = 12,927(4) A; z(Se) = 0,6210(3). Es wird betont, das die Struktur von MoS2 in vielen Buchern unrichtig angegeben wird, obwohl sie schon von Dickinson und Pauling [4] richtig beschrieben wurde. Berichtigte Atomabstande werden angegeben; das trigonale Prisma um Mo ist fast regelmasig.
Preparation and Crystal Structure of the Titanium and Hafnium Bismuthides Ti8Bi9and Hf8Bi9

The titanium bismuthide Ti8Bi9has been prepared by reaction of the elemental components in evacuated, sealed silica tubes and also by arc-melting. Its crystal structure is of a new type, which was determined from single-crystal X-ray data:P4/nmm,a=1027.7(1) pm,c=737.5(1) pm,Z=2,R=0.027 for 553 structure factors and 32 variable parameters. The titanium atoms occupy four different sites: two with octahedral and two with square-antiprismatic bismuth coordination. The bismuth atoms are located at three different sites with four, five, and seven titanium neighbors. An analysis of the Ti–Bi bonding distances (covering the range between 282 and 314 pm) leads to the conclusion that there are Ti–Ti bonding interactions (at distances between 293 and 307 pm). In addition, some weakly bonding Bi–Bi interactions (334–353 pm) are assumed. The compound Hf8Bi9has the same structure:a=1071.8(1) pm,c=752.0(1) pm.
Über die Synthese von Grisanonen-(3)

Versuche zur synthese von Grisanonen-(3), Grisandionen-(3.4′) und Δ2′-Grisendionen-(3.4′) werden beschrieben. 1-Aryloxy-cycloalkan-carbonsauren-(1) (III) geben mit Borfluorid-atherat oder Polyphosphorsaure Grisanone-(3) (IV), 1-Aryloxy-;4-benzyloxy-cyclohexan-carbonsauren-(1) (X) mit Borfluorid-atherat je nach den Umsetzungsbedingungen Grisanol-(4′)-one-(3) (XI) oder 4′-Benzyloxy-grisanone-(3) (XIV). Erstere werden zu Grisandionen-(3.4′) (XV) oxydiert, uber die 4′-Mesyloxy-Verbindungen zu Δ3′-Grisenonen-(3) (XIX) dehydratisiert. Dehydrierung der Grisandione(3.4′) mit Selendioxyd oder Bromierung in 3′-Stellung und anschliesende Bromwasserstoffabspaltung gibt Δ2′-Grisendione-(3.4′) (XIV). Ferner wird ein rationelles Verfahren zur Herstellung der 1-Aryloxy-cyclohexan-carbonsauren-(1) (III und X) angegeben.
Mass transfer in gas fluidized beds : scaling, modeling and particle size influence

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Will Time Tell? Exploring the Relationship Between Step Duration and Student Performance

In this paper, we explore how the time students take to solve a problem may relate to their success. Even though prior research indicates that students’ response times can provide some indication regarding correctness, time is not consistently and broadly used when modeling students’ performance. We aim to clarify the relationship between the step duration – that is, the time a student takes to carry out a step of a learning task – and the outcome of this step with respect to correctness for STEM-related courses. Then, we discuss our early findings, how they can be used to enhance student modeling and to provide meaningful and timely feedback to students.
Nanosecond Time‐Resolved Emission Spectroscopy of 1‐Anilino‐8‐Naphthalene Sulfonate

Nanosecond time‐resolved emission spectroscopy and fluorescence lifetime measurements are reported for 1‐anilino‐8‐naphthalene sulfonate. Time‐dependent spectral shifts are observed that are interpreted in terms of dipole reorientation of the solvent around the electronically excited molecule. Both the radiative and nonradiative transitions probabilities are observed to be strongly solvent dependent.
The filling of flexible carbon nanotubes by molten salts

The direct filling of flexible single-walled carbon nanotubes by model molten salts are described. The simulations advance on previous work, in which the carbon nanotubes were treated as fixed atomistic entities, by considering the carbon nanotubes as fully-flexible. The molten salts are described using two potential models, which vary in the relative energetic stability of two key bulk crystal structures. Small diameter carbon nanotubes are found to favour relatively low symmetry “ladder” and “hinged” structures, which can both be considered as formed from sections of square net sheet, in contrast to cylindrical geometries favoured when filling fixed carbon tubes. The small diameter tubes are also found to favour structures based on folding square, rather than hexagonal, nets. Additional energy minimisation calculations are performed in order to understand both the formation of the less symmetric structures and the favouring of square net-based structures. The role of the flexible tubes in controlling the filling mechanisms and kinetics is discussed. Larger diameter carbon tubes are found to favour relatively disordered internal structures.
Toxicity of bromate ions in drinking water and its determination using ion chromatography with post column derivatisation

Disinfection of drinking water is usually carried out by chlorination. This is a well-known and effective technology which has many advantages. However, during this process dangerous by-products such as trihalomethanes, as well as chlorate and chlorite are formed. The disinfection of bromide-containing source waters with ozone results in the production of bromate ions (BrO 3 ), which are formed as a result of a series of complex reactions between ozone and bromide ions present in water. Bromates are possible human carcinogens. For these reasons trace analysis of bromate and other oxyhalides by-products in waters has received considerable attention in recent years. This article describes the determination of bromate in drinking water by IC with post column derivatisation using NaBr/NaNO 2 and UV detection. The direct method allows the determination of bromate at low μg/dm 3 levels and sample pretreatment is not necessary.
Spectroscopic measurements of radial temperature distributions in short electric arcs

The authors report spectroscopic measurements of radial temperature distributions within the plasma of a short metal arc in air. A semi-automatic spectroscopic set-up enabled them to determine spatial-temporal temperature distributions in unstable arc channels. The absence of self-absorption for the used atomic lines within the plasma volume was checked by a careful analysis of line profiles with a Fabry-Perot interferometer. The evaluated temperature profile reveals a narrow peak near the electrode with a width of about 40 mu m, indicating a strong contraction of the current conducting region.
Mechanically strong and highly conductive graphene aerogel and its use as electrodes for electrochemical power sources

Mechanically strong and electrically conductive graphene aerogels can be prepared by either supercritical drying or freeze drying of hydrogel precursors synthesized from reduction of graphene oxide with L-ascorbic acid, and the resulting graphene aerogels possess the specific capacitance of 128 F g−1 with superior rate performance.
The private and public life domains of Arab youth in Canada: Acculturation, ethnic identity, social support, and adjustment

Participants were recruited primarily from online and student groups resulting in a total of 99 participants (74 females, 25 males; age range: 15-21). Having a positive Arab orientation predicted family satisfaction and having a positive European-Canadian orientation predicted school and living environment satisfaction, as well as fewer invalid school absences. These results corroborate previous research findings differentiating between psychological and sociocultural adjustment, but also show that having a positive Arab acculturation orientation predicts psychological adaptation in private domains and having a positive EuropeanCanadian acculturation orientation predicts psychological adaptation in public domains. Perceived social support received from family mediated the relation between Arab acculturation orientation and private life satisfaction, indicating that family support plays a crucial role in interpreting the relation between acculturation and adjustment. Gender comparisons revealed that males, as compared to females, reported stronger ethnic identities.
Bismuth Triflate-Catalyzed Three-Component Mannich-Type Reaction

Bismuth triflate catalyzes the Mannich-type reaction of a variety of in situ generated aldimines using aldehydes, anilines, and silyl enol ethers in a three-component reaction. The reaction proceeds rapidly and affords the corresponding protected β-amino ketones in high yields (up to 94%).
Light‐Triggered Molecular Devices: Photochemical Switching Of optical and Electrochemical Properties in Molecular Wire Type Diarylethene Species

Organic photochromic systems represent a starting point for the elaboration of light-triggered molecular switching devices. The novel bispyridinium and bispyridine compounds 12+ and 6 were synthesized as their uncyclized isomers from 3,5-dibromo-2-methylthiophene in overall yields of 43 and 44%, respectively. The diarylethene photochromes 2 and 10–13, substituted with electron donors and acceptors, were prepared from 5-methylthiophene-2-carboxaldehyde in 21–32% overall yield. All of the compounds were found to exhibit pronounced photochromic properties. Irradiation with UV light resulted in essentially complete photocyclization of the open forms to the intensely coloured closed isomers which could, in turn, be reconverted back to the open state with visible light of γ>600 nm. The absorption maxima of the described compounds in their closed forms are shifted far towards, and even into, the near-IR region. Whereas no thermochromic properties were observed for the open isomers, the rates of thermal decolouration of the cyclized forms was found to be highly dependent on the nature of the substituents on the thiophene rings. It was demonstrated that reversible photochemical interconversion between the two photochromic states could be used to effectively switch a number of physical properties. Thus, the molecules 12+ and 12 represent two kinds of redox switches, the former in reduction and the latter in oxidation, in which electron conduction is switched on in the closed state and off in the open state. Compound 12 may also be considered to be a photoswitchable analogue of tetrathiafulvalene type substances. On the other hand, compound 2 displays a marked increase in nonlinear optical activity on conversion from the open to the closed form. Such systems are prototypes of photoswitchable molecular wires where electron conduction and push-pull interaction can be reversibly modulated by an external stimulus, namely, irradiation by light.
Advanced Bioreduction of Commercially Important Azo Dyes: Modeling and Correlation with Electrochemical Characteristics

The anaerobic biodegradability of some commercially important colorants was investigated in upflow stirred packed-bed reactors (USPBR) containing biological activated carbon (BAC) system. Decolorization with very high reduction rates took place in the case of azo dyes. At least 80% of conversion was achieved for these dyes at a space time (τ) of 2.0 min or higher corresponding to a residence time of about 1.8 min at the most. On the contrary, nonazo xanthene dye was not converted in the anaerobic bioreactor system. A simple model was proposed to predict azo dye decolorization involving both heterogeneous catalysis and biological degradation. Adsorption studies for the dyes revealed that their adsorption affinity to activated carbon is not the key factor in the reduction process. Results from voltammetric experiments show that a correlation exists between electrochemical characteristic and anaerobic biodegradability of different azo dyes in the continuous USPBR-BAC catalytic system.
Spectroscopic study of surface-enhanced Raman scattering of rhodamine 6G on silver colloid

The aim of this work is to determine the influence of colloidal silver on the intensity of Raman scattering observed for rhodamine 6G (Rh6G) dissolved in the water. A special emphasis is placed on the exploration of the role of chloride ions and the influence of pH on the surface-enhanced Raman scattering (SERS) efficiency and stability of colloid. Rh6G is an extremely SERS active compound so in even relatively simple experiments up to 106 108 fold increase of Raman scattering is achieved. In the colloidal systems chloride ions are mainly responsible for an aggregation of nanoparticles what is the most important factor in the SERS enhancement. Moreover, Rh6G as a cationic dye co-adsorbing with chloride ions exhibits a strong direct interactions with the metallic surface. It results in additional enhancement of the intensity of Raman scattered light and probably is responsible for observed dimerization of Rh6G molecules. The reduction of pH by addition of nitric acid also leads to a decrease of surface potential of colloid and causes in its aggregation. Simply Raman spectrometer and UV-Vis spectrophotometer are used for spectroscopic measurements. The dynamic light scattering technique is used to estimate the size of particles and the degree of their aggregation. It is observed that the magnitude of SERS enhancement strongly depends on the kind and concentration of the used aggregating agent. The differences of SERS efficiency were reflected in the absorption spectra as well as in particles/aggregates size distribution.
Genetic divergence studies in aggregatum onion (Allium cepa L. var. aggregatum Don.) genotypes using Mahalanobis D2 analysis

Twenty genotypes of aggregatum onion were evaluated for eighteen growth, yield and quality characters to estimate the genetic diversity among them by Mahalanobis D2 statistics. The genotypes were grouped into seven clusters. Cluster V contained maximum number of genotypes (six genotypes) followed by cluster IV (four genotypes), cluster III (Three genotypes), cluster VI, II and I (Two genotypes). Cluster VII was monogenotypic. The clusters IV and VII had highest inter cluster distance. The maximum mean values for plant height, leaf length and yield per plot was observed by the genotypes of clusters II. The maximum number of leaves and number of tillers was recorded by the genotypes of the cluster V. Maximum leaf girth and maximum bulb length was observed by the genotypes of cluster VII. The genotypes of cluster I has shown maximum bulb diameter. The genotypes of cluster IV and VI recorded maximum number of bulbs. Maximum chlorophyll content and yield per plant was recorded by the genotypes of the cluster IV. Therefore it was concluded that these clusters and their genotypes could be intercrossed in order to achieve more variability.
Multiscale Attention Guided Network for COVID-19 Diagnosis Using Chest X-Ray Images

Coronavirus disease 2019 (COVID-19) is one of the most destructive pandemic after millennium, forcing the world to tackle a health crisis. Automated lung infections classification using chest X-ray (CXR) images could strengthen diagnostic capability when handling COVID-19. However, classifying COVID-19 from pneumonia cases using CXR image is a difficult task because of shared spatial characteristics, high feature variation and contrast diversity between cases. Moreover, massive data collection is impractical for a newly emerged disease, which limited the performance of data thirsty deep learning models. To address these challenges, Multiscale Attention Guided deep network with Soft Distance regularization (MAG-SD) is proposed to automatically classify COVID-19 from pneumonia CXR images. In MAG-SD, MA-Net is used to produce prediction vector and attention from multiscale feature maps. To improve the robustness of trained model and relieve the shortage of training data, attention guided augmentations along with a soft distance regularization are posed, which aims at generating meaningful augmentations and reduce noise. Our multiscale attention model achieves better classification performance on our pneumonia CXR image dataset. Plentiful experiments are proposed for MAG-SD which demonstrates its unique advantage in pneumonia classification over cutting-edge models. The code is available at https://github.com/JasonLeeGHub/MAG-SD.
Structural and thermal properties of polystyrene/CoAl-layered double hydroxide nanocomposites prepared via solvent blending: effect of LDH loading

Nanocomposites of polystyrene (PS) with modified CoAl-layered double hydroxide (CoAl–LDH) were prepared via simple solvent blending method and the effect of CoAl–LDH content on the structural and thermal properties was investigated. The structural and thermal properties of the nanocomposites were characterised by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy, thermogravimetric analysis and differential scanning calorimetry. The nano-scale dispersion of the CoAl–LDH layers in the PS matrix is verified by the (0 0 3) XRD reflection of the modified CoAl–LDH. The XRD data show that the exfoliated PS/CoAl–LDH nanocomposites can be obtained by controlling the LDH loading of about 5 wt%. TEM analysis also confirms the formation of exfoliated PS nanocomposites with 3 wt% and 5 wt% LDH loading. The thermal degradation temperature of the PS nanocomposite containing 5 wt% CoAl–LDH is found to be 12°C higher than that of pure PS when 50% weight loss is selected as a point of comparison. The glass transition temperature (T g) of PS nanocomposites is about 14°C higher than that of pure PS.
Synthesis, identification, and growth mechanism of Fe, Ni, and Co crystals encapsulated in multiwalled carbon nanocages

Nanometer size crystalline particles of α‐Fe, γ‐Fe, Ni, β‐Co, and Co3C encapsulated in multiwalled carbon cages are synthesized by a standard dc arc evaporation of composite anodes containing 10–15 wt. % each of the metals or their compounds. The typical particle size is ∼10 nm. Elemental analysis is made by x‐ray energy dispersive spectroscopy. The spectra show only the peaks associated with the respective metal and carbon. The stoichiometry and phase of the crystals are assigned from the characteristic lattice spacings obtained by high‐resolution transmission electron microscopy and x‐ray diffractometry. Particle size distribution is obtained from a statistical survey of electron micrographs. A statistical growth model is adequate for explaining the crystalline particle size distribution of the encapsulated crystals consisting of α‐Fe and γ‐Fe smaller than 15 nm. Significant deviation from the model is found for the encapsulated crystals consisting of α‐Fe and γ‐Fe larger than 15 nm, those of Ni larger than 4 nm, and those consisting of β‐Co and Co3C larger than 6 nm. The deviation is discussed in terms of encapsulation effect on the particle growth mechanism.
Porous structure dependent photoreactivity of graphitic carbon nitride under visible light

We demonstrate that graphitic carbon nitride can photoreduce CO2 to CO in the presence of water vapor and exhibit interesting porous structure dependent reactivity on photoreduction and photooxidation under visible light (λ > 420 nm). Graphitic carbon nitride was synthesized by directly heating the inexpensive melamine and the replacement of melamine with melamine hydrochloride could result in porousification in the final graphitic carbon nitride with much higher surface area (39 times) and more abundant pores, accompanied by a band gap increase of 0.13 eV. The porousification could significantly enhance the photoreactivity of graphitic carbon nitride in rhodamine B photooxidation by 9.4 times, but lower its activity in CO2 photoreduction by 4.6 times. The reasons for the porous structure dependent photoreactivity were investigated in detail. These new findings could shed light on the design of efficient photocatalysts and the tuning of their photoreactivity for environmental and energy applications.
Synthesis of X-type Zeolite from Dealuminated Kaolin by Reaction with Sulfuric Acid at High Temperature

X-type zeolite was synthesized from kaolin previously dealuminated through reaction with sulfuric acid at high temperature to raise its SiO2/Al2O3 ratio. All of the steps in the synthesis of X-type zeolite from dealuminated kaolin were studied. Parameters analyzed included temperature, time, stirring speed, and composition ratios. The optimum values for the variables were the following: In the gel formation step, temperature was 60 °C, time was 1 h, and stirring speed was 450 rpm. In the aging step, temperature was 20 °C and time was 12 h. In the crystallization step, temperature was 80 °C, time was 24 h, and stirring speed was 0 rpm. The optimum molar ratios were SiO2/Al2O3 = 3.2, (Na2O + K2O)/SiO2 = 1, H2O/(Na2O + K2O) = 30, and K2O/(Na2O + K2O) = 0.1. Some significant differences from other works were observed, particularly in the aging and crystallization steps. These variations in the synthesis process might be caused by changes in the kaolin structure occurring during dealumination with sulfuric acid.
Optical fiber pH sensor fabrication by means of indium tin oxide coated optical fiber refractometers

In this work, the fabrication of a novel optical fiber pH sensor is described. This optical fiber pH sensor is based on the utilization of a pH sensitive polymeric coating fabricated onto indium tin oxide coated optical fiber refractometers. The pH of the external medium modifies the thickness of the polymeric coating and hence the effective refractive index. Thus, ITO coated optical fiber refractometers based on electromagnetic resonances are used as suitable transducers in order to monitor the variations of the pH in the surrounding medium. The fabricated devices permit wavelength based pH detection in the near infra-red region, showing high sensitivity (17.5 nm/pH unit) and fast response. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)