Miracle-dz/UniFAR-FTUs huggingface dataset:
Highly active and stable synergistic Ir–IrO2 electro-catalyst for oxygen evolution reaction

ABSTRACT The design of efficient and stable electrocatalysts is still crucial to realize oxygen evolution reaction (OER) in acid and corrosive environment. Inspired by the metal/metal oxides catalysts, we hydrothermally synthesized Ir–IrO2 composites duly confirmed by X-ray diffraction, X-ray photoelectron spectroscopy, energy dispersive spectrometer (EDS), X-ray absorption data, and transmission electron microscope results. A low onset over-potential of merely 234 mV and a Tafel slope of 53 mV dec−1 were obtained for the prepared catalyst Ir–IrO2_0. 5AF. In addition, Ir–IrO2_0. 5AF catalyst retained high activity for long time under constant potential polarization. The enhanced performance is attributed to the introduction of lower valence Ir as hydrogen acceptor: hydrogen transfers from –OOH intermediate in OER to adjacent H acceptor site, forming intermediate with relatively lower Gibbs free energy, and resulting in higher activity. The present study emphasizes on important role of the lower valence composition in launching H acceptors and providing wide opportunities toward rational designing of efficient and stable electro-catalysts.
Capacitive deionization for nutrient recovery from wastewater with disinfection capability

This study demonstrates that capacitive deionization can be effectively used for the removal and recovery of dominant nitrogen (ammonium) and phosphorus (phosphate salts) species present in wastewater. Moreover, low concentrations of chlorine and other oxidants can be generated in situ for disinfection. With an applied voltage from 1.2 V to 3.0 V, salts, ammonium, and phosphorus can be quickly removed from water and adsorbed on the electrodes due to the formation of an electrical double layer, and results show that the removal efficiency was 77.5–91.2% for salts, 60.5–95.7% for ammonium, and 46.4–80.7% for phosphorus, respectively. In addition, most of the adsorbed ions are released back to the concentrate during regeneration, so high nutrient recovery can be accomplished as well. Such a simple electrochemical process can be promising to solve both nutrient and salinity problems after biological treatments for discharge and reuse, and the additional disinfection function adds further benefits to improve water quality and safety with low cost.
Synthesis and Solution Properties of a Rigid Helical Star Polymer: Three-Arm Star Poly(quinoxaline-2,3-diyl)

Six semiflexible helical three-arm star poly[5,8-dimethyl-6,7-bis(propoxymethyl)quinoxaline-2,3-diyl] (A3PQ) samples which have different arm lengths ranging in the weight-average molar mass Mw from 1.5 × 104 to 2.5 × 105 g mol–1 were synthesized via the living polymerization of the corresponding 1,2-diisocyanobenzene using a trifunctional palladium initiator. The particle scattering function P(q), the z-average mean-square radius of gyration ⟨S2⟩z, and the intrinsic viscosity [η] for the A3PQ samples were determined from light and small-angle X-ray scattering and viscosity measurements in tetrahydrofuran at 25 °C. The obtained data were compared with modern theories for the wormlike star. The experimental P(q) data were represented by the wormlike star model connected with a universal joint. The other data were comparably explained by the same model.
Activation of (salen)CoI complex by phosphorane for carbon dioxide transformation at ambient temperature and pressure

We report the activation of (salen)CoI complex 3g by a phosphorane to form a bifunctional catalyst for the reaction of carbon dioxide with terminal epoxides or aziridines at ambient temperature and 1 bar carbon dioxide pressure. Only 1.0 mol% of both (salen)CoI 3g and phosphorane 4d are required for cyclic carbonate synthesis, and the catalyst loading could even be lowered down to 0.1 mol%. Under these conditions, no polycarbonate formation is detected by NMR analysis. It is proposed that the high efficiency originates from the activation of (salen)CoI by a phosphorane to form a phosphorane–salen Co(III) complex with enhanced Lewis acidity for the electrophilic activation while generating an iodide anion as a Lewis base co-catalyst to facilitate the ring-opening of epoxides. Further investigation revealed that the phosphorane–(salen)CoI complex could also successfully catalyze the coupling of CO2 with aziridines under ambient conditions at a catalyst loading of 2.5 mol%.
Spectral Sample Reweighting, and Robust and “Heavy-Tailed” Mean Estimation

Robust mean estimation is the problem of returning a close approximation of the mean of a distribution on R given n points that are drawn from the distribution and are then corrupted by an adversary. A recent paper on robust mean estimation ([3]) describes the “spectral sample reweighting” problem. They then show that using an algorithm that solves the reweighting problem, it is possible to do robust mean estimation for covariance-bounded distributions and (non-robust) mean estimation in the “heavy-tailed” setting. In Section 2, we will define many terms that are commonly used in the robust mean estimation literature. Then, in Section 3, we will describe the spectral sample reweighting problem and the algorithm that can be used to solve it. In Section 4, we show how to solve the robust mean estimation problem using an algorithm for the spectral sample reweighting problem. In Section 5, we do the same for the “heavy-tailed” mean estimation problem.
Effet Maxwell-Wagner dans des multicouches: mesure et modèle de la charge d'interface

Avec l'expansion des technologies HVDC, il devient necessaire d'etudier la conduction des isolants non plus seulement pour la comprehension des phenomenes disruptifs, mais egalement pour predire la distribution des contraintes. Dans ce travail, l'effet Maxwell-Wagner dans des associations d'isolants est revisite, en considerant d'une part un modele avec une conductivite non lineaire en champ, et des mesures de charge d'espace donnant un acces direct a cette charge d'interface. Nous montrons que des mesures de charge d'espace permettent d'estimer la charge d'interface produite par effet Maxwell-Wagner entre deux dielectriques de nature differente. Incidemment, les mesures confirment que la distribution de champ electrique passe progressivement d'une distribution capacitive a une distribution resistive sous contrainte electrique prolongee.
Mechanical Properties and Degrading Behaviors of Aluminum Hypophosphite-Poly(Lactic Acid) (PLA) Nanocomposites

ABSTRACT The flame retardancy of poly(lactic acid) (PLA)/aluminum hypophosphite (AHP, phosphorous content = 41.87 wt.%) nanocomposites (PLA/(AHP-x), x = 15%, 20%, 25%; and x denotes the weight percentage content of AHP) was greatly enhanced by melt blending of AHP into PLA through twin-screw extruder and injection-molding process. The UL 94 V-0 flammability rating can be reached for PLA/(AHP-20%) with the LOI value over 28.8. The well dispersion of the AHP in PLA/(AHP-x) was investigated by FT-IR spectra under the line mapping model. Based on TGA results under a non-isothermal condition, the thermal degradation kinetics of PLA/(AHP-x) composites were studied by Kissinger’s, Ozawa’s and Flynn-Wall-Ozawa’s (FWO’s) methods. And those thermal degradation dynamic analyses showed lower activation energy (EK or EO) (from 155 to 122 kJ·mol–1) corresponded to higher content of AHP (from 15 to 25 wt.%) for PLA/(AHP-x) nanocomposites. Kissinger’s, FWO’s and Coast-Redfern’s methods were used to discriminate the kinetic models and kinetic parameters for the thermal degradation of PLA/(AHP-x), which suggested conversion function G (α) = [-ln(1-α)]2/3 or G (α) = α for the investigated process. The flame retardant PLA nanocomposites obtained in this study will become safety environment-friendly potential candidates in household and automobile engineering with high performance. GRAPHICAL ABSTRACT
First Nuclear DNA Amounts in more than 300 Angiosperms

Background and Aims Genome size (DNA C-value) data are key biodiversity characters of fundamental significance used in a wide variety of biological fields. Since 1976, Bennett and colleagues have made scattered published and unpublished genome size data more widely accessible by assembling them into user-friendly compilations. Initially these were published as hard copy lists, but since 1997 they have also been made available electronically (see the Plant DNA C-values database www.kew.org/cval/homepage.html). Nevertheless, at the Second Plant Genome Size Meeting in 2003, Bennett noted that as many as 1000 DNA C-value estimates were still unpublished and hence unavailable. Scientists were strongly encouraged to communicate such unpublished data. The present work combines the databasing experience of the Kew-based authors with the unpublished C-values produced by Zonneveld to make a large body of valuable genome size data available to the scientific community. Methods C-values for angiosperm species, selected primarily for their horticultural interest, were estimated by flow cytometry using the fluorochrome propidium iodide. The data were compiled into a table whose form is similar to previously published lists of DNA amounts by Bennett and colleagues. Key Results and Conclusions The present work contains C-values for 411 taxa including first values for 308 species not listed previously by Bennett and colleagues. Based on a recent estimate of the global published output of angiosperm DNA C-value data (i.e. 200 first C-value estimates per annum) the present work equals 15 years of average global published output; and constitutes over 12 % of the latest 5-year global target set by the Second Plant Genome Size Workshop (see www.kew.org/cval/workshopreport.html). Hopefully, the present example will encourage others to unveil further valuable data which otherwise may lie forever unpublished and unavailable for comparative analyses.
Living with dementia during the COVID-19 pandemic: coping and support needs of community dwelling people with dementia and their family carers. : Research findings from the IDEAL COVID-19 Dementia Initiative (IDEAL-CDI)

We interviewed people with dementia and carers from the IDEAL cohort to find out how the COVID-19 lockdown and continuing restrictions affected those living with dementia. Some people with dementia coped well, while others coped with difficulty or were only just coping. The additional stress of COVID-19 exacerbated pre-existing coping difficulties. For many, social isolation increased anxiety. Some felt that lack of activity or lack of social contact caused a decline in their abilities to manage everyday tasks. Confusion about COVID-19 rules or difficulty remembering what to do led to anxiety when leaving the house. People felt that members of the public might not understand their particular needs. While some carers felt they were coping well, others experienced stress when having to leave the home because the person with dementia might not be safe if left alone. Some experienced increased strain in the caring relationship compounded by an uncertainty about future availability of respite. Some were concerned about the complex health needs of the person with dementia alongside COVID-19 risk and lack of personalised information. Both people with dementia and carers talked about the importance of access to safe outdoor space. People were anxious about how others would react or behave towards them regarding keeping a distance if they went out. Being connected to friends, family and wider community or support groups was important to help combat the effects of isolation. People from BAME communities worried about their increased vulnerability to the virus. A lack of trust in Government guidance and in health care services added to their anxiety. However, some benefitted from strong community and faith group involvement. What might be helpful for people with dementia? • Reablement to help regain or maintain skills • Personalised health advice regarding managing COVID-19 risk and the opportunity to ask questions. • Identification of people with dementia who live alone and an assessment of their needs. What might be helpful for carers? • Needs assessment in regard to respite. • Novel forms of respite care that incorporate social distancing. What might be helpful for both carers and people with dementia? • Access to COVID-safe outdoor spaces. • Continuation and expansion of ‘just checking’ services. • Support to get online and use the internet. • Communication and information through non-digital means. • Community COVID-19 ‘dementia awareness’ initiatives. What might be helpful for people from Black and minority ethnic groups? • Addressing concerns about their increased risk of COVID-19. • Directing information and support through existing community and faith groups.
Organic semiconductor p-doping : toward a better understanding of the doping mechanisms and integration of the p-doped layer in organic photodetectors

Contrairement a l’electronique conventionnelle a base de silicium, l’electronique organique offre de nouvelles possibilites telles que la production sur grande surface et a faible bilan thermique, ou encore l’utilisation de substrats flexibles et transparents. Afin d’ameliorer la conductivite des semi-conducteurs ainsi que le contact polymere-electrode metallique, le dopage en electrons et en trous doit etre developpe dans les materiaux organiques. Dans cette these, des techniques de caracterisation electrique (courant tension a temperature variable, capacite, spectroscopie d’admittance), optique (spectroscopie UV-visible et de photoluminescence) et materiau (RMN, MEB, MET) ont ete utilisees pour analyser l’influence de la concentration en dopant Mo(tfd-COCF3)3 sur les proprietes electriques du polymere PBDTTT-c et ameliorer notre comprehension du mecanisme mis en jeu dans le dopage. La couche dopee a ete integree avec succes dans un photodetecteur organique en utilisant une technique de laminage afin de remplacer la couche habituellement utilisee de PEDOT:PSS, connue pour generer des problemes de stabilite dans le dispositif. Enfin, la technique de laminage et le savoir acquis sur le dopage des semi-conducteurs organiques ont permis d’etudier l’impact du dopage non intentionnel par l’oxygene sur les performances des photodetecteurs organiques. Bien qu’il soit encore necessaire de renforcer notre comprehension sur le dopage des semi-conducteurs organiques, ameliorer la technique de depot par laminage et introduire la couche dopee dans divers dispositifs imprimes, les resultats presentes dans cette these sont prometteurs pour le developpement de l’electronique organique.
Smart photocatalytic removal of ammonia through molecular recognition of zinc ferrite/reduced graphene oxide hybrid catalyst under visible-light irradiation

Zinc ferrite loaded with reduced graphene oxide (ZnFe2O4/rGO) and zinc ferrite (ZnFe2O4) catalysts were synthesized via a one-spot method. The catalysts were characterized by X-ray diffraction, transmission electron microscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, UV-vis diffuse reflectance spectroscopy, surface photovoltage spectroscopy and X-ray photoelectron spectroscopy. Results revealed that the as-synthesized ZnFe2O4/rGO and ZnFe2O4 particles were cubic spinel-type ZnFe2O4 with space group number of Fd3m, and that their average diameters were 7.4 and 7.0 nm, respectively. The photocatalytic results indicated that the ZnFe2O4/rGO hybrid catalyst possesses higher activity than that of the single ZnFe2O4 component under visible-light irradiation. More importantly, the ZnFe2O4/rGO catalyst could recognize ammonia from an organic pollutant-ammonia mixed solution and selectively degrade ammonia and nitrogen gas based on the coordination recognition between Zn cations on ZnFe2O4 and ammonia in solution. Fourier-transform infrared, Raman and X-ray photoelectron spectra confirmed that ammonia was selectively adsorbed on ZnFe2O4 particles. The shifts of Zn 2p3/2 and Zn 2p1/2 binding energies confirmed the coordination between Zn cations and ammonia. The surface photovoltage spectra revealed that the photo-generated holes moved to the surface of ZnFe2O4 particles upon incident visible-light irradiation, and degraded ammonia adsorbed on the catalyst surface. These findings will encourage more investigations of photocatalysis based on coordination recognition.
Water-Stable Nanoscale Zirconium-Based Metal–Organic Frameworks for the Effective Removal of Glyphosate from Aqueous Media

Two water-stable zirconium-based metal–organic frameworks (MOFs) (NU-1000 and UiO-67) have been synthesized in various size scales (100–2000 nm) for the adsorptive removal of glyphosate from the aqueous media. Both NU-1000 and UiO-67 possess a three-dimensional structure; NU-1000 consists of triangular micropores and wide mesoporous channels (31 Å), whereas UiO-67 has cage-like pores [octahedral (16 Å) and tetrahedral (14 Å) cages]. NU-1000 comprises Zr6(μ3-O)4(μ3-OH)4(H2O)4(OH)4, and UiO-67 contains Zr6O4(OH)4 as secondary building units. These units act as Lewis acid nodes and can interact with the Lewis base phosphate group of the glyphosate. The time taken for reaching equilibrium is found to be reduced considerably as the size of the MOF decreases. The smaller the particle size, the lesser is the diffusion barrier for the analyte, which enhances the interaction between Lewis acidic metal nodes and the Lewis basic center of the glyphosate molecule. NU-1000 was found to be better compared to UiO-67, both in terms of efficiency and reusability. This might be due to the larger pore diameters of the NU-1000. Theoretical calculations revealed that the interaction energy of glyphosate with the nodes of NU-1000 is higher (−37.63 KJ mol–1) compared to UiO-67 (−17.37 KJ mol–1), which might be the possible reason for the higher efficiency of NU-1000.
On the Estimation of Heston-Nandi GARCH Using Returns and/or Options: A Simulation-based Approach

In this thesis, the Heston-Nandi GARCH(1,1) (henceforth, HN-GARCH) option pricing model is fitted via 4 maximum likelihood-based estimation and calibration approaches using simulated returns and/or options. The purpose is to examine the benefits of the joint estimation using both returns and options over the fundamental returns-only estimation on GARCH models. From our empirical studies, with the additional option sample, we can improve the efficiency of the estimates for HNGARCH parameters. Nonetheless, the improvements for the risk premium factor, both from empirical standard errors, and sample RMSEs, are insignificant. In addition, option prices are simulated with a pre-defined noise structure and with different noise levels, to demonstrate the consequence when we have a noisy option sample versus a less noisy one. The result shows that, with added option samples the RMSEs for estimated GARCH parameters are reduced dramatically, even with a very noisy option data set. This suggests that calibrating GARCH option pricing models with a relatively short return series of around 6 years, plus an option sample is more ideal than using a long return series of 20 years alone. Finally, as a by-product, we studied which type of options leads to the larger calibration improvements. Our controlled experiment confirms that out-of-the-money, short-maturity options are the best choices.
Identification of the Profile of Vulnerable Population to Elaborate Efficient Employment Strategy: Proposition of a Quantitative-creative Approach

Brazilian public managers have been structuring and updating policies to support workers’ employment and income strategies. However, when the vulnerable individual has social, emotional, or technical limitations, success in this operation becomes uncertain. This research aim was to propose a methodology to identify profiles in vulnerable populations, viewing to promote the efficient elaboration of employment and income strategies. The unit of analysis was vulnerable population of waste pickers, in a large city from South Brazil, in the scope of a municipal program named "All of us are Porto Alegre". A literature review allowed the identification of tools from marketing, economy and design adequate to profile analysis. A workshop with social educators responsible for giving support to the individuals. Insights from workshop and the literature allowed the proposition of a methodology including cluster analysis and the creative tool named personas. The methodological approach suggests it is adequate in confirming the differences in profiles. The theoretical contribution lies in the use of quantitative-creativity tools to support policymaking. The practical contribution is to provide consistent information for governmental decision-making at the labor access market.
Tests for Differences between Least Squares and Robust Regression Coefficients

At the present time there is no well accepted test for determining whether or not robust regression parameter estimates are significantly different than least squares estimates. Thus. we propose and demonstrate the efficacy of two Wald-like statistical tests for the above purposes using MM-estimators for robust regression. The two tests have corresponding appropriate null and alternative hypotheses, the latter of which allows for bias in both least squares and robust estimates. The tests are designed to detect significant differences between least squares and robust estimates due to both inefficiency of least squares under fat-tailed non-normality and large biases of least squares relative to robust regression coefficient estimators under bias inducing distributions. The asymptotic normality of the test statistics is established and the finite sample level and power of the two tests are evaluated by Monte Carlo, which yields promising test performance results. Our simulation studies focus on the choice of two well-known MM-estimator loss functions, the bisquare loss function due to J. W. Tukey as introduced in Beaton and Tukey (1974) and an optimal bias robust loss function due to Yohai and Zamar (1997). While one of the two tests is preferred if only one test is used, we show that use of both tests can be useful in diagnosing the reason for rejection of a null hypothesis.
Tacit Collusion among Dominant Banks: Evidence from Round-Yard Loan Pricing

While there is no apparent reason for loan spreads to cluster at certain numbers, we find that around 70% of loans have round-yard spreads (i.e., multiples of 25 basis points). We hypothesize that dominant banks implicitly collude by using the round-yards as focal pricing points when negotiating with their borrowers. The tacit collusion leads to higher spreads and total costs of the round-yard-priced loans than non-round-yard-priced loans. Consistent with our tacit collusion hypothesis, dominant banks round up rather than round down loan spreads to the multiples of yards. Moreover, round-yard pricing is more prevalent among lower-quality and non-repeat borrowers. Overall, we provide the first evidence that dominant banks use round-yard pricing as an effective tool for tacit collusion in the loan market.