Miracle-dz/UniFAR-FTUs huggingface dataset:
Electrochromic nanostructured tungsten oxide films by sol-gel: Structure and intercalation properties

As-deposited sol-gel derived amorphous tungsten oxide films transform into nanostructured films with an interconnected framework of grains and pores and a dominant triclinic crystalline phase upon annealing at 250 degrees C. Transmission electron microscopy and scanning electron microscopy images clearly reveal the annealing-induced microstructural evolution for the film. Subsequent to lithium intercalation, the film annealed at 250 degrees C shows quasi-reversible structural changes, as ascertained by X-ray diffraction and Fourier transform infrared spectral data. Dynamic transmission modulation for film revealed a high optical modulation of 72% (gimel=650nm) and a coloration efficiency maximum of 132 cm(2) C-1 at 800 nm under a lithium intercalation level of x = 0.20. X-ray photoelectron spectroscopy of the W 4f core levels demonstrated a progressive increase in the W5+ content at the expense of W6+ proportion as the insertion coefficient was raised from 0 to 0.25, with 0.20 as the threshold value above which the W5+ content exceeds the W6+ proportion. A new W4+ state also appears which acts to lower the coloration efficiency for x >= 0.22. The presence of charged oxygen interstitials in the vicinity of electrochemically active tungsten sites is also responsible for the coloration efficiency decline at high ion insertion levels.
Luminescence spectroscopy of Mn2+ rock-forming carbonates

Abstract Cathodoluminescence emission spectra and luminescence excitation spectra of Mn2+ in calcites, dolomites, magnesites, a manganocalcite and a rhodochrosite have been measured at both room temperature and 77 K. Ligand-field parameters have been calculated from the excitation spectra which reflect the size of the metal cation site in which the Mn2+ ion resides. The technique of luminescence excitation spectra has enabled the absorption profile of Mn2+ in Mg and Ca sites in dolomite to be separately determined. The variation of the distribution of Mn2+ between Mg and Ca sites in dolomites is demonstrated and discussed in terms of a simple model. It is concluded that the distribution of Mn2+ in dolomites may well provide information about its conditions of formation and/or subsequent alteration.
The Risk-Return Relationship in Crude Oil Markets during COVID-19 Pandemic: Evidence from Time-Varying Coefficient GARCH-in-Mean Model

In this paper, we propose the new time-varying coefficient GARCH-in-Mean model The benefit of our model is to allow the risk-return parameter in the mean equation to vary over time At the end of 2019 to the beginning of 2020, the world witnessed two shocking events: COVID-19 pandemic and 2020 oil price war So, we decide to use the daily data from December 2, 2019 to May 29, 2020, which cover these two major events The purpose of this study is to find the dynamic movement between risk and return in four major oil markets: Brent, West Texas Intermediate, Dubai, and Singapore Exchange, during COVID-19 pandemic and 2020 oil price war For the European oil market, our model found a significant and positive risk-return relationship in Brent during March 26-April 21, 2020 For the North America oil market, our model found a significant positive risk return relationship in West Texas Intermediate (WTI) during March 12-May 8, 2020 For the Middle East oil market, we found a significant and positive risk-return relationship in Dubai during March 12-April 14, 2020 Lastly, for the South East Asia oil market, we found a significant positive risk return relationship in Singapore Exchange (SGX) from March 9-May 29, 2020
Characterization of β-casein Gene Sequence Variants in Cholistani Cattle

Ruqayya Bint Khalid1, Asif Nadeem1,2*, Maryam Javed1, Muhammad Zubair Shabbir3 and Masroor Ellahi Babar4 1Institute of Biochemistry and Biotechnology, University of Veterinary and Animal Sciences, Lahore, Pakistan. 2Department of Biotechnology, Virtual University of Pakistan, Lahore, Pakistan 3Department of Microbiology, University of Veterinary and Animal Sciences, Lahore, Pakistan; 4The University of Agriculture, Dera Ismail Khan, Khyber Pakhtunkhwa, Pakistan Article Information Received 10 June 2020 Revised 03 July 2020 Accepted 07 July 2020 Available online 06 November 2020
Epitaxial Growth of Highly Luminescent CdSe/CdS Core/Shell Nanocrystals with Photostability and Electronic Accessibility

The synthesis of epitaxially grown, wurtzite CdSe/CdS core/shell nanocrystals is reported. Shells of up to three monolayers in thickness were grown on cores ranging in diameter from 23 to 39 A. Shell growth was controllable to within a tenth of a monolayer and was consistently accompanied by a red shift of the absorption spectrum, an increase of the room temperature photoluminescence quantum yield (up to at least 50%), and an increase in the photostability. Shell growth was shown to be uniform and epitaxial by the use of X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), and optical spectroscopy. The experimental results indicate that in the excited state the hole is confined to the core and the electron is delocalized throughout the entire structure. The photostability can be explained by the confinement of the hole, while the delocalization of the electron results in a degree of electronic accessibility that makes these nanocrystals.
Physical Gelation of Amorphous Polymers in a Mixture of Solvent and Nonsolvent

The formation of phase inversion membranes made by immersion precipitation from a ternary system consisting of an amorphous polymer, a solvent, and a nonsolvent has been rationalized by assuming a gelation process. The treatise is based on a hypothesis developed by Berghmans for a binary system consisting of a polymer and a solvent. The ternary phase diagram for the mixture of H2O−NMP (N-methylpyrrolidone)−PES (poly(ether sulfone)) was determined at 25 °C. In this system three boundaries could be identified, i.e., a vitrification, a gelation, and a binodal boundary. It was found that for this system and a system composed of H2O−DMAC (N,N-dimethylacetamide)−PSF (polysulfone), vitrification is the only mechanism responsible for the structure fixation of membranes prepared by liquid−liquid demixing due to immersion precipitation. For the system of MPD (2-methyl-2,4-pentanediol)−NMP−PES, it was found that a membrane can be formed by vitrification as a result of immersion precipitation prior to liquid−liquid d.
Security-Oriented Trellis Code Design for Spatial Modulation

To achieve physical layer security (PLS) with a flexible implementation, a novel design named security-oriented trellis coded spatial-modulation (SO-TCSM) is proposed in this article, where the transmitter does not know the channel state information (CSI) of wiretapping channels and relies on the legitimate CSI to vary the mapping patterns for the antenna information and the radiated information, aiming at the optimisation of free Euclidean distances between the resultant SO-TCSM symbols. Eavesdroppers cannot decode the confidential information delivered in the legitimate link, as they do not know the legitimate CSI and, hence, have no basis to acquire the transmitter’s mapping pattern of the moment. Moreover, the SO-TCSM symbols are then compensated to maximise their Euclidean distances, which further improves the legitimate receiver’s decoding performance while enhancing the PLS. However, the compensation results in high transmit power when the legitimate channels are in deep fades. To boost the energy efficiency, a constraint is set to limit the transmit power. Under this constraint, the SO-TCSM performance is investigated in terms of bit error rate and transmit power consumption. The outcome of these investigations substantiates that, compared to conventional TCSM designs, our SO-TCSM achieves better performance in the legitimate link with lower decoding complexity.
X-Ray diffraction line-broadening study on two vibrating, dry-milling procedures in kaolinites

Due to the great technological importance of the microstructure of kaolinite, characterizing its evolution during dry milling of kaolin and analyzing the microstructural information obtained from different methods were the main aims of this work. The microstructural alteration of kaolinite is evaluated by X-ray diffraction and electron microscopy methods, comparing the results obtained and analyzing the correlations between them. The Warren-Averbach and Voigt-function methods of X-ray diffraction microstructural analysis have been applied successfully to the study of the effects of two different, vibrating-cup dry-milling configurations in the microstructure of kaolinite from the reflections corresponding to (001) diffracting planes. The crystallite-size estimates obtained from the two methods correlate well. Field emission scanning electron microscopy measurements of kaolinite particle thickness are in good agreement with the crystallite size estimated by the two methods. The Warren-Averbach method also provided estimates of the contribution to line broadening. Vibrating-cup milling has been proved to be a more efficient method of strain comminution of kaolinites than other milling techniques, reaching extensive microstructural degradation within seconds.
Assessing sovereign debt sustainability using a wealth-based fiscal indicator

Working in the context of an endogenous growth model with the public sector, we show that forward-looking agents' optimizing behavior typically gives rise to a wealth-based, rather than to an output-based, sustainability index of government policy. New insights emerge from calibrating the index to European countries along with the U.S. and Japan as reference countries.
On accuracy of Wertheim's thermodynamic perturbation theory for primitive models of water

Applicability and accuracy of Wertheim's thermodynamic perturbation theory (TPT) is examined in detail using three qualitatively different primitive models of water. Theoretical results for the thermodynamic properties of these models obtained using the theory in its first order (TPT1) are presented and compared with new simulation data. Individual approximations used in the implementation of the TPT1 to get close analytic results are also assessed by evaluating the appropriate quantities by computer simulations. It is shown that an approximate description of the reference system affects the overall performance of the TPT1 only marginally, if at all, and that the observed discrepancies between theory and experiment for all models are rather inherent to the theory itself and result from the neglect of higher order terms (i.e. certain graphs) contributing to the excess Helmholtz free energy.
Influence of Samarium doping on zinc borophosphate glasses

The use of rare earth metals as dopant components in oxide glasses is a new research field of inorganic optical functional materials due to the simple preparation process, stable chemical properties and high thermal stability. This study supplements and summarized results we have obtained in recent years. The focus is on samarium doped zinc oxide-rich borophosphate glasses. The obtained glasses were investigated by powder X-ray diffraction, differential scanning calorimetry, infrared spectroscopy and photoluminescence analysis. The synthesized Sm-doped borophosphates are predominantly homogeneous and non-hygroscopic. They are mainly amorphous with the presence of one or more crystalline phases in some of them Zn3(BO3)(PO4), Zn5B4O11, SmPO4 and ZnO. They have the typical structure of borophosphate glasses the presence of PO4 tetrahedra and BO4 tetrahedra. The Sm-doped ZnO-rich borophosphate glasses have a potential for practical application in optical devices for engineering, electronics and medicine.
Coupled Three-Phase Converter Concept and an Example: A Coupled Ten-Switch Three-Phase Three-Level Inverter

The bridge arms of traditional three-phase multilevel converters are independent of each other; thus, more active switches and passive diodes are required. In order to reduce the number of devices, a coupled three-phase converter architecture, which is suitable for both dc–ac and ac–dc converters, is presented. Based on this architecture, a ten-switch three-phase three-level (10S-3P-3L) inverter is proposed in this article. The proposed topology employs only ten active switches and no additional diodes, which helps to cut size, weight, and costs of system. The proposed space vector modulation enables 10S-3P-3L inverter to operate full modulation indexes. A comparison between the proposed inverter with some existing topologies in terms of device voltage and current stresses, conduction loss, switching loss, and other parameters is made to highlight its excellent performance. Moreover, the experimental results from a 3-kW experimental prototype reveal that the proposed inverter offers superior power quality.
Blackberry pomace microspheres: An approach on anthocyanin degradation

ABSTRACT Blackberry pomace is a rich source of antioxidant compounds, including anthocyanins, but these compounds degrade easily in the presence of high temperatures. Therefore, the present study aimed to evaluate the effect of temperature on anthocyanin degradation in spray-dried blackberry pomace extract. Maltodextrin was used as a drying aid agent in a spray drying process to produce microspheres. The experiment was set up at Maringá-PR, Brazil (23º 25’ 31” S, 51º 56’ 19” W, 596 m altitude). The thermal stability of anthocyanins was evaluated in the presence and absence of copigments at different temperatures ranging from 70 °C to 100 °C using degradation kinetics. The role of maltodextrin in protecting anthocyanins during the spray drying process was studied at high temperatures. The highest anthocyanin stability was found at 70 °C. We also studied the effect of copigment phytic acid on the stability of anthocyanin and found that the copigment plays an important role in anthocyanin protection at high temperatures. The spray drying process with maltodextrin is a feasible technique for the preservation of food products and can improve anthocyanin’s thermal stability. The reuse of industrial wastes, such as blackberry pomace along with preservation techniques, can be a good strategy to reduce their negative impact on the environment.
A User-Item Collaborative Filtering System to Predict Online Learning Outcome

Article history: Received: 27 June, 2020 Accepted: 31 August, 2020 Online: 09 September, 2020 Education has seen the rapid development of online learning. Many researchers have conducted studies on the use of recommendation systems in online learning. However, until now, several similar studies still focus on the accuracy of the prediction results. Various obstacles were encountered related to changes in the face to face learning process into online learning. This study uses the User-Item Collaborative Filtering method to predict student learning outcomes as a basis for providing recommendations to students. Data on student online learning outcomes were extracted using several methods as a basis for determining and assessing their learning outcomes. The dataset we use is dummy to match the original data. The findings of this study reveal that one of the reinforcing factors that affect student achievement in online learning is the quiz score. The students' high achievement in the quizzes was also balanced by their active involvement during the learning process. Based on the evaluation of the recommendation system, it is known that the gradient boosted tree model is the best model for predicting the final score of student online learning with an accuracy calculated using the highest correlation of 0.7 and the smallest absolute error of 13.0 and root mean square error of 17.9. Based on the results of the evaluation, this study provides recommendations in the form of material links and learning archives that are useful for students to be able to carry out independent learning.
Bubble size and velocity measurement in gas—liquid systems: Application of fiber optic technique to pilot plant scale

A new fiber optic probe was developed for the detection and measurement of bubble sizes and velocities in a gas-liquid column. The probe is made of a single 1 mm plastic fiber with a sharp wedge tip. The calibration was carried out on a laboratory scale unit using a cine-photographic technique to verify the measurements. Bubble velocities were calculated using two identical parallel fibers and the cross-correlation technique. With the velocities and the passage time determined, it was then possible to determine the bubble diameter. Bubble diameters were within 10% of the measurements obtained with the cine-photographic technique. After calibration, measurements were carried out on a pilot scale unit. On a mis au point une nouvelle sonde a fibres optiques pour la detection et la mesure des tailles de bulles et des vitesses dans une colonne gaz—liquide. La sonde se compose d'une simple fibre plastique de 1 mm muni d'un bout pointu et en biseau. On a effectue la calibration dans une unite a l'echelle du laboratoire en recourant a la technique cinematographique afin de verifier les mesures. Les vitesses de bulles ont ete calculees au moyen de deux fibres paralleles identiques et par la technique de correlations croisees. Apres avoir determine les vitesses et le temps de passage, on a pu determiner le diametre des bulles. Les diametres de bulles concordent a 10% pres aux mesures obtenues par la technique cinematographique. Des mesures ont ete prises sur une unite a l'echelle pilote apres la calibration.
Quantitative analysis of diffuse X-ray scattering in partially transformed 3C-SiC single crystals

The X-ray scattering of partially transformed 3C-SiC single crystals is considered in detail. Extended diffuse scattering streaks, originating from stacking faults (SFs) lying in the {111} planes, are clearly observed in the wide-range reciprocal-space maps. The intensity distribution along the diffuse streaks is simulated with a model including the contributions of the diffuse scattering originating from the SFs [based on the pioneering theoretical description given by Kabra, Pandey & Lele (1986). J. Mater. Sci. 21, 1654–1666], the coherent scattering emanating from untransformed areas of the crystals and all θ-dependent terms that affect the scattered intensity (the layer structure factor, the irradiated volume and the polarization of the beam). The quantitative simulation of the diffuse streaks reveals that the transformation occurs through the glide of partial dislocations and allows one to derive the transformation level. It is shown that the 3C polytype is indeed unstable at high temperature. However, it is further shown that defect-free 3C-SiC single crystals remain stable at temperatures where 3C-SiC is known to be usually unstable (2173 K). The origin of this apparent stability is very likely of kinetic nature, i.e. the lack of crystalline defects inhibits the transformation.
The application of singularity theory to isothermal autocatalytic reactions: the influence of uncatalysed reactions

The influence of a direct, uncatalysed reaction A→Brate=kua on the stationary-state behaviour of the cubic ‘autocatalator ’ A+2B→3Brate=k1ab2,B→Crate=k2b in an isothermal, well-stirred, open reactor is studied by singularity methods. It is shown that the dependence on the mean residence time of the extent of conversion of A in the stationary state has five different patterns possible. Three of these are similar to those found in the absence of the uncatalysed step: unique, isola and mushroom. The two extra patterns, a breaking wave (a single, S-shaped hysteresis loop) and breaking wave plus isola, require non-zero ku. The uncatalysed reaction also effects the behaviour at long residence time where the system tends to complete conversion. This kinetic scheme represents the simplest, isothermal chemical model with a full unfolding of a winged-cusp singularity and requires only the minimum number of parameters. Sustained oscillatory behaviour, arising from Hopf bifurcations, is also exhibited and is again influenced by the uncatalysed step. The main results can be summarized as follows. ku=0multiplestationarystates(isola,mushroom)andoscillations;0<ku<1200k1a02multiplestationarystates(isola,mushroom,breakingwave,breakingwaveandisola)andoscillations;1200k1a02<ku<1195k1a02multiplestationarystates(isola,mushroom,breakingwave,breakingwaveandisola),nooscillations;1195k1a02<ku<127k1a02multiplestationarystates(breakingwaveonly),nooscillations;127k1a02<kunomultiplestationarystates,nooscillations,.
An Examination of COVID-19 Outbreaks in South American Prisons and Jails

ABSTRACT This article highlights intra-regional variation in the extent of the COVID-19 outbreaks in South America generally and then provides an assessment of the nature and extent of outbreaks in South American prisons. Country-level differences in front-end, within-prison, and back-end early release mechanisms are also described. The article concludes with an assessment of two alternative future directions for prison reform across this region.
Gender Differences in Determinants of Customer Satisfaction in Beauty and Cosmetic E-commerce

This study investigates the gender differences in determinants of customers’ satisfaction when purchasing online beauty and cosmetics products in Vietnamese market. To do so, we construct a data set via online survey of 419 Vietnamese customers including both males and females, and examine such sample using t-tests and multiple regressions. Our regression model is constructed based on our five-construct model including online shopping experience, customer service, external incentives, security and privacy, and personal characteristics. The t-tests results reveal that the mean difference of customer satisfaction (negative coefficient) between the two groups of customers (females and males) is statistically significant. This suggests that the purchasing satisfaction of male customers is significantly higher than that of their female counterparts. Similarly, we also find that male customers are more satisfied with their online shopping experience, customer service and external incentives offered by the online sellers than female peers. Furthermore, regression results for full sample show that, on average, the online shopping experience, customer service and external incentives are significantly and positively related to customer satisfaction. Yet, such positive effect of customer service on customer satisfaction is more likely for males while females’ satisfaction is more positively influenced by security and privacy.