Miracle-dz/UniFAR-FTUs huggingface dataset:
Recombination activity of iron‐related complexes in silicon studied by temperature dependent carrier lifetime measurements

Carrier recombination centers related with iron complexes in p‐type silicon are studied by microwave and light‐induced absorption techniques. Both thermal‐ and photoactivation are used to decompose iron–boron pairs and to study the impact on the recombination lifetime. Due to photodissociation of iron–boron pairs the lifetime increases for high level injection. Efficient recombination occurs via an acceptor level at Ec−0.29 eV as derived from the temperature dependence of carrier lifetime.
Neutral particle diagnostics for ohmically and auxiliary heated tokamaks

Protons and hydrogen atoms in a plasma undergo charge‐exchange collisions which give rise to an energetic charge‐exchange flux emerging from the plasma. The intensity and energy distribution of the charge‐exchange flux is measured separately for hydrogen or deuterium. Besides discussing the basic principles and the experimental techniques, this report concentrates on plasma characteristics accessible to neutral particle diagnostics. From the energy distribution of the charge exchange flux, the ion energy distribution can be inferred. In the case of a thermal plasma the measurement of the ion temperature profile allows the analysis of the ion energy transport, and with auxiliary heating the ion heating efficiency can be estimated. From the absolute intensity of the charge‐exchange flux the hydrogen atom density can be determined; strong toroidal variation, with sharp increases at limiter and gas input valve, is observed. The atom flux which leaves the plasma hits the wall and forms one branch of plasma wall interaction which can be investigated by measuring the backscattering of neutrals from the wall and by analyzing the wall sputtering due to charge‐exchange atoms. Neutral particle diagnostics carried out in the divertor chamber of a divertor tokamak reveal strong plasma wall interaction at the neutralizer plate.
Decoupling the electronic, geometric and interfacial contributions to support effects in heterogeneous catalysis

We examine the role of the oxide support in modulating the activity and selectivity of common oxide-supported transition metal heterogeneous catalysts. Using representative models of various supported nanoparticle systems, we use computational studies based on density functional theory to decouple the metal–support interaction in terms of electronic and geometric effects, including the role of support oxygen vacancies and the reactivity of perimeter sites at the metal–oxide boundary. We target Fischer–Tropsch conversion on silica- and titania-supported Rh as a representative catalyst system but interpret our results in terms of a fairly general model of the metal–support interaction and its associated catalytic relevance. We find that geometric restructuring of the nanoparticle in the presence of the support generally leads to stronger adsorption energies, while the electronic interaction (primarily via charge transfer) depends strongly on the nature of the oxide and is modulated by oxygen vacancies on reducible supports. We show that these changes in adsorption energies lead to associated modifications of reaction thermodynamics and kinetics. We also show that ‘dual’ sites at the metal–oxide interface often represent the thermodynamically favourable binding sites for oxygen-containing species, particularly when associated with adjacent support vacancy sites. Our studies suggest a conceptually simple model for considering the influence of oxide supports on catalytic activity and highlight the potential importance of accounting for interfacially bound adsorbates in kinetic models.
Effect of trace metals on reactive crystallization of gypsum

The effect of Fe2+, Fe3+, and Cr3+ ions on crystallization of calcium sulfate dihydrate (gypsum) produced by the reaction between calcium hydroxide suspension and sulphuric acid solution was investigated at 3.5 pH and 65°C in the absence and presence of 2500 ppm citric acid concentration. Crystal size distributions, filtration rates, and morphology of gypsum were determined and discussed as a function of ion concentration. Average particle size of gypsum was not affected significantly by the presence of Fe2+, Fe3+, and Cr3+ ions individually. Variation of gypsum morphology depending on ion concentration affected the filtration characteristics. The presence of Fe3+ or Cr3+ ions besides 2500 ppm citric acid influenced both average particle size and filtration characteristics. The effect of citric acid on gypsum morphology was suppressed at high Fe3+ and Cr3+ ion concentrations. The change of morphology is related to the complex formation between Fe3+ or Cr3+ ions and citric acid at high ion concentrations. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electron spin resonance and related phenomena of low-dimensional electronic systems in III–V compounds

In this work, dc and high-frequency transport phenomena directed primarily at spin properties in two-dimensional electronic systems (2DES) and the quantum Hall effect (QHE) are reviewed. The spin properties are probed by electron spin resonance (ESR). The experimental methods used are presented and the theoretical background based on k ⋅ p theory is given. The effects of further reducing the dimensionality are discussed in the context of experiments on zero-dimensional systems, ‘quantum dots’. To place this work in perspective, the ESR of ‘bulk’, three-dimensional systems and of strained bulk materials is also treated. Experimental results are presented to clarify the origin of the interaction between the 2DES and the electromagnetic radiation responsible for ESR. These results are compared with theoretical work on the electric dipole and magnetic dipole oscillator strength. The magnetic dipole interaction is found to dominate. The 2DES is subject to electron–electron interaction effects. While no influence on the resonance energy, in accordance with ‘Kohn's theorem’, is found, indications of many-body effects on the temperature dependence of the spin polarization of the ESR are observed. This is in accordance with other experimental and theoretical works which also found (or predicted) the formation of states with reduced spin polarization. While the influence of the interactions between electrons on the ESR frequency is absent, the hyperfine interaction between electrons and nuclei causes a shift (called the Overhauser shift) of the position of the ESR when the nuclei are spin polarized. Experimental results indicate that the appearance of this shift coincides with magnetic field regions where the plateaus of the quantum Hall effect are present.
Computer program (CHMASS) for calculating theoretical characteristic mass values in electrothermal atomic absorption spectrometry

A computer program (CHMASS) is described that calculates characteristic mass (mo) values for electrothermal atomic absorption spectrometry (ETAAS) following user-specified input of atomizer type or dimensions and atomization temperature. All the necessary spectroscopic and physical parameters for calculating mo values for 40 elements (and 44 analytical wavelengths) commonly determined by ETAAS are included in the database. Application of the program is illustrated by several theoretical and practical examples: (i) a study of the effect of atomization temperature on absorption and diffusion coefficients for silver; (ii) an investigation of how the sample injection hole limits the maximum attainable ETAAS sensitivity for copper as the tube length is increased; (iii) optimization of the atomization temperature for the determination of cadmium in a standard reference material; and (iv) a comparison of several commercial atomizer designs as regards the calculated atomization efficiencies using data from the manufacturers' literature. This last comparison provides further evidence for the superiority of platform atomization and integrated absorbance measurements over wall atomization combined with peak height evaluation.
A Research Protocol of Hands-On Healthy Meal Preparation Intervention (Kidchen Study) to Improve Children’s Nutritional Outcomes

The objective of this paper is to describe the protocol of a 12-week hands-on healthy meal preparation intervention among children, up to a 3-month follow-up. The aim of KidChen Study (kids in kitchen) is to improve children’s nutritional outcomes. In this randomized-controlled trial, simple random sampling will be used to select schools in Kuala Lumpur, Malaysia. Subsequently, the selected schools (n=2) will be assigned randomly to either the intervention or control group. The current study will include healthy Malaysian children aged 10–11 years old with no serious disease or food allergy. The intervention is based on Social Cognitive Theory that addresses personal and environmental factors for changing children’s behaviour. Children from the intervention group will receive a 60-minute home food environment module with their parents consisting of nutrition talk, healthy food tasting, parent-child quiz; and five 60 minute interactive hands-on healthy meal preparation modules focusing on core food groups coupled withstorytelling sessions to incorporate nutrition education. Outcome measures are children’s psychosocial factors towards healthy meal preparation (knowledge, attitude, practice, self-efficacy), dietary behaviour, food consumption pattern, home food availability and anthropometric measures (BMI-for-age z-score, body fat percentage, waist circumference). Repeated measures ANOVA will be used to evaluate the intervention outcomes. KidChen Study is an experiential learning approach to instil a positive attitude towards nutrition and empower children with nutrition skills. We anticipate that the intervention will advocate healthy eating behaviour among children, impacting their nutritional outcomes over time.
Replica-exchange molecular dynamics simulation of diffracted X-ray tracking

We examine the effects of the nanocrystal covalently bonded to one end, utilizing replica-exchange molecular dynamics simulation of a peptide with the sequence Ac-YGKAAAAKAAAAKAAAAKC-amide, to simulate the diffraction X-ray tracking (DXT) method. We performed three different simulations in this study. A simulation with no constraint, a simulation with one end fixed, and a simulation with one end fixed and also considering the effect of the nanocrystal by changing the mass of the sulfur atom in the C-terminus, which covalently bonded with the Au nanocrystal in diffraction DXT method, was performed. The average configuration parameters of the three simulations are compared and discussed. We analyzed our simulation results utilizing principal component analysis. The obtained free-energy landscape indicated that the condition of the DXT technique will not affect the global-minimum state, however, it may affect the folding pathway.
Does quality of electricity matter? Household-level evidence from the Philippines

Abstract The Philippines is a country that faces many development challenges, including providing reliable and good quality electricity. Access to good quality electricity connection matters because it affects many aspects that increase productivity (e.g. education, health and business) and can make lives easier and more comfortable. While access has improved over time, many households still suffer from poor quality of their connection brought about by incidents of power outages, fluctuations and low voltage. This article attempts to examine whether better electricity quality improves household welfare. We apply a two-stage probit-ordered probit model to overcome endogeneity caused by reverse causation between electricity quality and household income. We find that households experiencing better electricity quality decrease the probability of remaining in the lowest income category by 23%.
Chymotrypsin‐Catalyzed Peptide Synthesis in Deep Eutectic Solvents

Deep eutectic solvents (DESs) are formed by mixing quaternary ammonium salts (e.g., choline chloride) and hydrogen-bond donors (e.g., glycerol or urea), which leads to biodegradable and readily available ionic solvents at room temperature. Analogous to other ionic liquids, DESs represent a promising reaction media if hydrophobic and hydrophilic substrates need to be combined. This paper assesses DESs as reaction media for chymotrypsin-catalyzed peptide synthesis. After careful determination of the reaction conditions (e.g., water content, enzyme loading), α-chymotrypsin displayed high activity for peptide synthesis in choline chloride/glycerol mixtures to afford productivities of ca. 20 g L–1 h–1 and with complete selectivity for the peptide, which is in contrast to the detrimental hydrolysis pathway observed in aqueous media. The nonimmobilized suspended enzyme could be reused several times by simple filtration with excellent to moderate activities. Overall, the results reported suggest that choline chloride based DESs may become promising neoteric solvents for peptide synthesis through biocatalysis.
Virulence potential of Aeromonas hydrophila isolated from apparently healthy freshwater food fish

Aeromonas hydrophila is considered an important pathogen of fish causing substantial economic loss in aquaculture worldwide. The objective of the current study was to assess the virulence potential of A. hydrophila strains isolated from gills of apparently healthy fish using phenotypic assays, PCR based genotypic tests, and in-vivo pathogenicity assays in Indian catfish, Clarias magur. For this, motile aeromonads (n = 50) were isolated from gills of apparently healthy freshwater food fish (n = 50) collected from domestic fish market. Gill swabs were incubated for primary enrichment in alkaline peptone water supplemented with cephalothin (10 mg/mL) for 12 hours followed by plating on Starch Ampicillin Agar. A single big yellow colony was selected from each sample, purified, and presumptively identified as Aeromonas with the help of Aerokey-II. Out of the fifty isolates of Aeromonas, five isolates of diverse origin (9C, 10G1, 7C, 10C and 4P) were confirmed to be A. hydrophila by automated bacterial identification system VITEK 2 with confidence interval of 90–98%. In the phenotypic assays, strains 9C and 10G1 showed high serum resistance, swimming and swarming activity and low biofilm producing capabilities, which were indicative of putative virulence. Both the strains belonged to genotype aah+act+alt+ascV+eno+lip+ast+ on the basis of detection of virulence genes by PCR, i.e. extracellular haemolysin (aah), cytolytic enterotoxin (act), heat-labile cytotonic enterotoxin (alt), type-III secretion system (ascV), enolase (eno), lipase (lip) and heat-stable cytotonic enterotoxin (ast). In-vivo pathogenicity assays confirmed that both the strains were pathogenic to magur fish. The LD50 for 9C strain was 6.81 × 104 CFU/mL and 7.62 × 105 CFU/mL for 10G1strain. In conclusion, our phenotypic and genotypic findings showed that A. hydrophila isolated from apparently healthy fish harbour number of important virulence genes/factors and could have important implications in triggering disease in farmed fish under stress.
Solvent-Free Atom Transfer Radical Polymerization in the Synthesis of Fe2O3@Polystyrene Core−Shell Nanoparticles

This paper describes the use of solvent-free atom transfer radical polymerization (ATRP) in the synthesis of Fe2O3@polystyrene (PS) core−shell nanoparticles. In this approach, oleic acid stabilized Fe2O3 nanoparticles were ligand exchanged with 2-bromo-2-methylpropionic acid (Br-MPA), the initiator for ATRP. These Fe2O3 nanoparticles become soluble in styrene and can be used as macroinitiators for solvent-free ATRP. The synthesized core−shell nanoparticles were characterized by transmission electron microscopy (TEM), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), ultraviolet−visible (UV−vis) spectroscopy, and Fourier transform-infrared (FT-IR) spectroscopy. Well-defined Fe2O3@PS core−shell nanoparticles were obtained. The glassy transition temperature of PS was studied using DSC, and the molecular weight of PS was characterized by GPC. The unique aspects of this solvent-free ATRP in the synthesis of well-defined polymer-coated nanoparticles will be discussed.
Metal ion–humic substance interaction

Peat and aquatic humic and fulvic acids have been isolated and characterized from a site at Whitray Fell in the area of the Forest of Bowland, UK. The substances cover a range of molecular masses from approximately 2800 (aquatic fulvic acid) to 40500 (peat humic acid). The enthalpies of interaction of these humic substances with a range of metal ions, including Cu2+, Cd2+, La3+ and Al3+, have been measured by microcalorimetry in aqueous solutions of ionic strengths ranging from ca. 50 mmol dm−3 to 5 mol dm−3 at 25 °C. Apart from the interactions of La3+ ions at low ionic strength, the enthalpies of interaction were endothermic, in marked contrast to what would be expected for the complexing of metal ions by chemical groupings known to be present in humic substances such as carboxylate, hydroxy and phenolic groups. By representing the humic molecules by a solvent and ion penetrable sphere surrounded by a diffuse electrical double layer, the thermodynamic parameters for the discharge of the double layer were estimated. The enthalpy change on discharge of the humic-associated double layer is endothermic and ionic strength dependent and of the same magnitude as the experimental enthalpies of ion interaction with the humic substances. In contrast the enthalpy change on discharge of the humic molecules is exothermic. These observations suggest that the discharge of the electrical double layers makes a significant contribution to the enthalpy changes on ion interaction with humic substances. However, the major contribution to the Gibbs energy change on discharge of the electrical double layer arises from a large increase in entropy.
Contrasting Recent and Future ITCZ Changes From Distinct Tropical Warming Patterns

This study synthesizes the observed trends and projected changes in the Intertropical Convergence Zones (ITCZs). Under future warming, the seasonal ITCZs are projected to shift equatorward, widen, and weaken. The equatorward‐shifted seasonal ITCZs cause a squeeze of the annual‐mean zonal‐mean tropical ascent. Over 1979–2014, however, the seasonal ITCZs have shifted poleward in South Pacific and generally narrowed and strengthened. The observed annual‐mean zonal‐mean changes are largely opposite to the future squeeze. Such contrasting ITCZ changes are attributed to the distinct tropical warming patterns. Specifically, the equatorial Pacific has cooled following a phase change in the Pacific Decadal Oscillation (PDO) but will warm more than the tropics in future. The ITCZ response to tropical warming pattern is consistent with thermodynamic/energetic theories and demonstrated through SST‐forced experiments. In the coming decades, a positive PDO can act jointly with anthropogenically forced equatorial warming, leading to substantial ITCZ changes that are distinct from recent trends.
Synthesis of Chiral 2,5-Bis(oxazolinyl)thiophenes and Their Application as Chiral Shift Reagents for 1,1′-Bi-2-naphthol

A series of C2-symmetrical chiral 2,5-bis(4′-alkyloxazolin-2-yl) thiophenes (thiobox) have been synthesized from thiophene-2, 5-dicarboxylic acid by sequential amidation with a chiral ethanolamine, conversion of hydroxyl to chloro group, and base-promoted oxazoline ring formation. As demonstrated by ( - )-2, 5-Ws[4′-( S)-isopropyloxazolin-2′-yl] thiophene, these thiobox systems exhibited remarkable chirality recognition of 1, 1′-bi-2-naphthol giving rise to pronounced shifts in the lH NMR signals of the latter axial chiral compound at the positions of C-3, C-4, C-5, and C-8.
Factors Affecting Youth Physical Activities: Evidence from Russia

The article provides an assessment of the factors that may affect the probability and intensity of physical activity among young Russians aged 15-24. The analysis is based on the data from the Russian Longitudinal Monitoring Survey (RLMS), 2000–2016 (n=21,703). Econometric analysis shows that there is a positive relationship between the physical activity probability and the indicators such as educational level, household per capita income, and living in capital cities. There is also a negative relationship between the probability of physical activity and individual’s characteristics such as smoking, family status (marriage), employment status (having a job). Relationship between the probability and intensity of physical activity and such features as alcohol consumption, body mass index and subjective health assessment is inconclusive. Implementation of measures aimed at increasing the physical activity of young Russians taking into account the stimulating or restraining factors may increase the productivity of physical exercise and further improve health condition and contribute to a longer lifespan in Russia. Acknowledgments. The project was funded by the HSE Basic Research Program (2018).
Nutraceutical Properties of Pecan Kernels Are Affected by Soil Zinc Fertilizer Application

Pecan (Carya illinoinensis) has high kernel antioxidant activity and unsaturated fatty acid content, which contribute to its nutraceutical properties. In the western United States, where soils are typically alkaline, pecan trees require frequent zinc (Zn) fertilizer applications to maintain normal canopy growth and nut production. Our objective was to investigate the effects of tree Zn fertilization on nutraceutical properties of ‘Wichita’ and ‘Western’ pecan kernels. Trees were fertilized with ethylenediaminetetraacetic acid (EDTA) chelated Zn, which was applied to the soil at one of three seasonal rates for a total of three treatments: 0 (control), 2.2, or 4.4 kg·ha−1 Zn. Nut samples were collected and homogenized for analyses of kernel oil yield, hydrophilic antioxidant capacity, fatty acid profile, and γ-tocopherol content. Although soil Zn treatments did not significantly affect antioxidant capacity of defatted pecan kernels, Zn application had significant positive effects on both total kernel oil yield and γ-tocopherol content compared with the control. In conclusion, soil application of Zn fertilizer may increase the human health-promoting aspects of pecan kernels, a valuable attribute among health-conscious consumers.
Modelling, Investigation, and Feasibility of Stratospheric Broadband mm-Wave 5G and beyond Networks for Aviation

Recent advances in communication systems provide an enabling technology for aircraft connection and safety. A promising communication system that uses stratospheric platforms provides an efficient and improved communication performance and can be an efficient solution for establishing communication networks for aviation. Therefore, in this paper, a novel communication network based on stratospheric basestation (SB) is proposed to provide fifth-generation (5G) and beyond services for civil aviation aircrafts to improve global flight connectivity, control, and safety. The proposed aircraft–SB network is demonstrated, and its coverage geometry is modelled and investigated. As the 5G and beyond networks use millimeter wave frequency bands (mm-wave), the performance of different atmospheric losses including gaseous absorption, rain, and fog/cloud is analyzed to investigate the system’s practical feasibility at different 5G proposed frequencies ranging from 3.5 to 66 GHz through a flight model including three distinct stages which are takeoff/landing, climbing/descending, and cruise stages. Also, handover scenarios in the proposed aircraft–SB network are investigated and analyzed at the proposed 5G frequencies. In addition, the aircraft–SB 5G network is compared to the most recent low-Earth orbit (LEO) Internet satellites where the proposed system is expected to provide low latency, less atmospheric attenuation, longer aircraft–SB link duration, and very low handover rate.