Miracle-dz/UniFAR-FTUs huggingface dataset:
Porous silicon formation: A quantum wire effect

Porous silicon layers grown on nondegenerated p‐type silicon electrodes in hydrofluoric acid electrolytes are translucent for visible light, which is equivalent to an increased band gap compared to bulk silicon. It will be shown that a two‐dimensional quantum confinement (quantum wire) in the very narrow walls between the pores not only explains the change in band‐gap energy but may also be the key to better understanding the dissolution mechanism that leads to porous silicon formation.
Synthesis of porous emulsion‐templated monoliths from a pulp mill by‐product

Black liquor is a by-product of the paper mill Kraft process that deserves more valorization than its present use as low-grade fuel. In this work, we present an original approach allowing the preparation of macroporous interconnected monolithic materials using as-received black liquor as main raw material. The process involves the formulation of an oil-in-water medium internal phase emulsion as soft templating porosity medium. The oil (internal phase) used is castor oil, whereas the continuous phase is constituted of black liquor containing a hydrophilic surfactant and epichlorohydrin as lignin crosslinking agent. Due to the high viscosity of the system, a specially designed emulsifying device was employed. The proper choices of the surfactant and emulsification conditions allow obtaining cellular biopolymers with almost monodisperse, interconnected void structure and satisfactory mechanical properties. These innovative results are promising for the future development of fully bio-based emulsion-derived materials. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Pharmaceutical wastewater degradation: effective and economical treatment using waste-metallic iron shavings

Industrial wastewater generated by a drug manufacturing plant located in Spain was degraded by Fenton oxidation processes, which employ waste-metallic iron shavings as heterogeneous zero-valent iron (ZVI) catalyst and hydrogen peroxide. The effluent comprises a complex mixture of organic substances which are very refractory to common conventional treatments and it is characterized by a low BOD/COD ratio. The stirring speed or the particle size has been found to be the determining factors, greatly influencing the degradation of the organic pollutants present in the wastewater. The influence of the initial hydrogen peroxide concentration has also been evaluated. The optimal conditions for degradation led to total organic carbon (TOC) reductions of up to 60%. The remarkable results of TOC mineralization could also be attributed to the physico-chemical modification of the ZVI during the oxidizing process. This study shows that the ZVI/H2O2 system can be considered as an easy, economic and effective alternative solution as a pre-treatment step before biological treatments.
Laser Ablation and Solution ICP‐MS Determination of Rare Earth Elements in USGS BIR‐1G, BHVO‐2G and BCR‐2G Glass Reference Materials

Data are reported for rare earth elements (REE) in three geological glass reference materials (BIR‐1G, BHVO‐2G and BCR‐2G) using a UV (266 nm) laser ablation ICP‐MS system and the classical (HF‐HClO4) acid decomposition method, followed by conventional nebulisation ICP‐MS. External calibration of laser ablation analyses was performed using NIST SRM reference materials with internal standardisation using 29Si and 44Ca. Replicate analyses of reference basaltic glasses yielded an analytical precision of 1‐5% (RSD) for all the elements by solution ICP‐MS and 1‐8% (RSD) by laser ablation ICP‐MS. The relative differences between the REE concentrations measured by solution and laser ablation ICP‐MS compared with the reference values were generally less than 11 % for most elements. The largest deviations occurred for La determined by solution ICP‐MS in BIR‐1G. The results of both solution and laser ablation ICP‐MS agreed well, generally better than 7%, with the exception of La, Pr and Sm in BIR‐1G. The measured REE laser ablation data for BIR‐1G, BHVO‐2G and BCR‐2G agreed with the previously published data on these basaltic reference glasses, within a range of 0‐10% for most elements. No significant influences were observed for the predicted spectral interferences on some REE isotopes in the analysis of basaltic glasses.
Headspace Solid-Phase Microextraction (HS-SPME) and Solid-Phase Extraction (SPE) Concentration for Quantification of Malodorous Substances in Piggery Wastewater

Quantification of malodorous substances at trace concentration levels in piggery wastewater remains a great challenge for environmental studies. The objective of this study was to determine the 4-methylphenol, 4-ethylphenol, indole and skatole (3-methylindole) of piggery wastewaters in anaerobic facilities by headspace solid-phase microextraction (HS-SPME) and solid-phase extraction (SPE) pre-concentration. The validation results of both pre-concentrations revealed high selectivity and sensitivity. The detection of malodorous substances can provide clues to track the source of these contaminants. The results of real sample detection showed that all of these malodor substances appeared in both influent and effluent wastewaters.
Decomposition of hydrogen peroxide in the presence of activated carbons with different characteristics

BACKGROUND: Catalytic ozonation promoted by activated carbon is a promising advanced oxidation process used in water treatment. Hydrogen peroxide generated as a by-product from the reaction of ozone with some surface groups on the activated carbon or from the oxidation of some organic compounds present in the water being treated seems to play a key role in the catalytic ozonation process. Hydrogen peroxide decomposition promoted by two granular activated carbons (GAC) of different characteristics (Hydraffin P110 and Chemviron SSP-4) has been studied in a batch reactor. The operating variables investigated were the stirring speed, temperature, pH and particle size. Also, the influence of metals on the GAC surface, that can catalyze hydrogen peroxide decomposition, was observed. RESULTS: Chemviron SSP-4 showed a higher activity to decompose hydrogen peroxide than HydraffinP110 (70 and 50% of hydrogen peroxide removed after 2 h process, respectively). Regardless of the activated carbon used, hydrogen peroxide decomposition was clearly controlled by the mass transfer, although temperature and pH conditions exerted a remarkable influence on the process. Catalytic ozonation in the presence of activated carbon and hydrogen peroxide greatly improved the mineralization of oxalic acid (a very recalcitrant target compound). About 70% TOC (total organic carbon) depletion was observed after 1 h reaction in this combined system, much higher than the mineralization achieved by the single processes used. CONCLUSIONS: Of the two activated carbons studied, Chemviron SSP-4 with an acidic nature presented a higher activity to decompose hydrogen peroxide. However the influence of the operating variables was quite similar in both cases. Experiments carried out in the presence of tert-butanol confirmed the appearance of radical species. A kinetic study indicated that the process was controlled by the internal mass transfer and the chemical reaction on the surface of the activated carbon. The catalytic activity of hydrogen peroxide in oxalic acid ozonation promoted by activated carbon (O3/AC/H2O2) was also studied. The results revealed the synergetic activity of the system O3/AC/H2O2 to remove oxalic acid. Copyright © 2010 Society of Chemical Industry
Polybrominated diphenyl ethers and hexabromocyclododecane in sediment and fish from a Swedish River

Fish and sediments from several places along the Swedish River Viskan, sampled in 1995, were analyzed for polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD). The samples were collected up‐ and downstream from several possible point sources (textile industries) for these compounds. Tetrabromodiphenyl ethers (TeBDEs), pentabromodiphenyl ethers (PeBDEs), and decabromodiphenyl ether (DeBDE [BDE209]) were found in sediment. Tetrabromodiphenyl ethers and PeBDEs were also found in fish. Hexabromocyclododecane was identified in sediment and fish. Large fish to sediment ratios for TeBDE, PeBDEs, and HBCD indicate that these are highly bioavailable, whereas BDE209 seems not to be as bioavailable. The lowest PBDE and HBCD levels were found upstream of the industries and concentrations generally increased progressively further downstream as more industries were passed. This is in agreement with earlier investigations of PBDEs in fish from the same river. Many brominated compounds are photolabile, which can complicate their analysis. Under the conditions used in this investigation it was observed that BDE209 in a solvent that was subject to the clean‐up procedure partly decomposed to compounds with shorter retention times, whereas BDE209 seemed to be stable in the sample extracts. Another matrix effect could be observed in the increased sensitivity obtained for some of the investigated compounds in fish and sediment extracts as compared to standard solutions. This effect may obscure analytical results obtained with electron capture mass spectrometric detections.
Salt effects on the cloud point of the poly(ethylene oxide)+ water system

The cloud point of high-molecular-weight poly(ethylene oxide), PEO, in aqueous salt solution has been determined as a function of the salt concentration for all potassium halides, alkali-metal chlorides and alkali-metal hydroxides. Our theoretical model for the pure PEO+water system (J. Chem. Soc., Faraday Trans. 1, 1981, 77, 2053) has been extended to include the effects of salt on the phase separation. Basic features of the present model are a hydration shell with enhanced structuring of water as well as a zone with decreased salt concentration surround each chain. Overlaps of such regions are involved in polymer–polymer contacts and imply transfer of water molecules and ions from the proximity of the chains to the bulk solution, which gives important contributions to the free energy of interaction. The existence of the salt-deficient zone is explained as a consequence of asymmetric hydration of the ions near the polymer. The effects of the zone are large enough to account for the influence of salts on the clouding. The experimental differences found for the alkali-metal halides have been rationalized mainly in terms of varying degrees of salt penetration into the region around the chain.
Impact Of Long-Term Storage On The Instrumental Textural Properties Of Frozen Common Carp (Cyprinus Carpio, L.) Flesh

The aim of the work was to measure and confirm changes in the qualitative properties of frozen carp flesh (Cyprinus carpio L.) during 84 days of storage at -20°C, using instrumental texture profile analysis focused on hardness, cohesiveness, and springiness. Hardness in fresh fish was 2.908 N, in fish stored 28 days 1.238 N, after 56 days 0.505 N, and after 84 days 0.491 N. Cohesiveness (dimensionless unit) in fresh fish was 0.838, after 28 days 0.740, after 56 days 0.720, and after 84 days 0.712. Springiness (dimensionless unit) in fresh fish was 0.682, after 28 days 0.625, after 56 days 0.577, and at 84 days of storage 0.534. The texture profile analysis effect was determined by several regression and linear models. It is possible to calculate a certain time period in which changes develop up to the level of 50% of deterioration—in hardness 17.5 days and in cohesiveness 12.9 days, as this was proven to a defined significance level (P > 0.01). Only changes in springiness showed a linear regression in the level of 0.002 (rounded) for each day. Studies showed that the intensity of the most important changes in instrumental textural properties occurred during the initial 56 days after freezing and after up to 84 days of storage the changes continued at a lesser rate.
Nanoenergetic Composite of Mesoporous Iron Oxide and Aluminum Nanoparticles

Ordered mesoporous Fe2O3 was synthesized using cetyltrimethylammonium chloride (CTAC) and polyethylene glycol octadecyl ether (Brij 76) surfactant templates. The gel time was monitored as a function of the concentration ratio of precursor to the surfactant. As-prepared FeOOH gels were extracted in ethanol to remove the surfactant and calcined at 200–400°C for 6 h so that α-Fe2O3 is produced. The FTIR spectra of these gels reveal complete removal of surfactant and water impurities and the presence of Fe-O vibrations. TEM images show ordering of mesopores in the gels prepared using surfactant templating and no ordering of the pores in the gels prepared without surfactant. The gels after calcinations were mixed with aluminum nanoparticles to prepare nanoenergetic composites. The burn rate of the nanocomposites containing ordered mesoporous Fe2O3 mixed with Al nanoparticles was compared with the one containing Fe2O3 with no ordering of mesopores and Al nanoparticles.
Sorption kinetics and impact of temperature, ionic strength and colloid concentration on the adsorption of plutonium-239 by inorganic colloids

Abstract Plutonium (Pu) is one of the primary actinides of concern for long-term disposal and storage of nuclear waste. Strong sorption of Pu onto colloids of iron oxide, clay, and silica could result in colloid-facilitated transport of this actinide in groundwater systems. However, fundamental data on Pu sorption to colloids is sparse, resulting in large uncertainties in long-term predictions of colloid-facilitated Pu transport. This sparseness of data and the potential to significantly reduce uncertainties in predictive models served as a motivation for this study. The authors investigated the sorption and desorption behaviors of 239Pu(V) on three types of inorganic colloids (hematite, montmorillonite and silica), with adsorption being measured as a function of temperature, ionic strength and colloid concentration for each colloid. Natural ground water collected from Well-13 near Yucca Mountain, Nevada, and synthetic ground water (SYN.J-13) were used in the experiments. The results indicated that the adsorption of 239Pu(V) onto hematite colloids was faster and had a higher partition coefficient (Kp, ml g-1) than onto montmorillonite or silica colloids in both J-13 and SYN.J-13 waters. Temperature did not significantly influence the adsorption of 239Pu(V) onto hematite and silica colloids, but the adsorption of 239Pu(V) onto montmorillonite colloids increased significantly with increasing temperature. While ionic strength did not significantly influence the adsorption of 239Pu(V) onto hematite colloids, an increase in ionic strength decreased the adsorption of 239Pu onto montmorillonite and silica colloids. Adsorption of 239Pu(V) per unit mass of colloid was much higher at low colloid concentrations than at high colloid concentrations. Desorption of 239Pu from 239Pu-loaded colloids was considerably slower than the adsorption process.
Organometallic Synthesis of Size‐Controlled Polycrystalline Ruthenium Nanoparticles in the Presence of Alcohols

Ruthenium nanoparticles of controlled size have been prepared by decomposition of the organometallic precursor Ru(cod)(cot) (cod = 1,5‐cyclooctadiene, cot = 1,3,5‐cyclooctatriene) under an H2 atmosphere in either a pure alcohol or an alcohol/THF mixture as solvent and in the absence of further stabilizer. The particles were characterized by transmission electron microscopy (TEM), high‐resolution electron microscopy (HREM), X‐ray diffraction (XRD), wide‐angle X‐ray scattering (WAXS), and X‐ray photoelectron spectroscopy (XPS). The colloidal solutions are stable for long periods of time, in some cases longer than one year. TEM images reveal in most cases the presence of polycrystalline sponge‐like particles of regular spherical shape and homogeneous size or, in some cases, the presence of isolated and well‐dispersed monocrystalline particles, depending upon the alkyl chain length of the alcohol used. In all cases the size distributions are relatively narrow. WAXS and XRD analyses indicate the exclusive presence of hexagonal close‐packed (hcp) ruthenium in these materials. The size of the particles can be controlled by adjusting the reaction temperature or the composition of the solvent mixture. In case of MeOH/THF mixtures, a linear correlation was established between the solvent composition and the size of the particles in the range of 4–85 nm. In the absence of stirring, small individual monocrystalline Ru particles are formed inside superstructures that assemble in some cases into monolayers. Finally, these materials are promising in catalytic hydrogenation of arenes under mild conditions.
Electronic Structure And Magnetism of Novel Diluted Magnetic Semiconductors CdGeP 2 : Mn and ZnGeP 2 : Mn

Chalcopyrite II-IV-V 2 semiconductors CdGeP 2 : Mn and ZnGeP 2 : Mn are new types of diluted magnetic semiconductors (DMSs). Since their ferromagnetic Curie temperatures are much higher than room temperature, these DMSs are good candidates for materials to be used in spintronics devices. Their electronic and magnetic structures have been investigated using the first-principles calculations based on the Korringa-Kohn-Rostoker coherent-potential-approximation and local-density-approximation (KKR-CPA-LDA) methods. When Cd or Zn atoms are substituted by Mn atoms, the ground state magnetic structure is spinglass-like. On the other hand, if Mn atoms substitute Ge atoms, the system becomes ferromagnetic through the double-exchange mechanism. However, the calculation of the formation energies shows that this system is not energetically favorable. Instead, the system with vacancies (Cd, Vc, Mn)GeP 2 or a non-stoichiometric (Cd, Ge, Mn)GeP 2 are also ferromagnetic and, moreover, energetically stable. We conclude that either of these variants possess a ferromagnetic phase of the kind CdGeP 2 : Mn. Similar conclusions are obtained for ZnGeP 2 : Mn.
Studies on Generation and Characterization of Nano Aluminium Nitride Using Wire Explosion Technique

The focus of the present work is to produce high purity nanoparticles of aluminium nitride by wire explosion technique and investigate its microstructure and physicochemical behavior by certain physico‐chemical diagnostic studies viz. X‐ray diffraction, TEM, EDAX, FTIR and TG-DTA. The influence of processing parameters on wire explosion technique is studied in detail. Grain growth kinetics of microstructural evolution of nano aluminium nitride is discussed.
Microemulsion nanocomposites: phase diagram, rheology and structure using a combined small angle neutron scattering and reverse Monte Carlo approach

The effect of silica nanoparticles on transient microemulsion networks made of microemulsion droplets and telechelic copolymer molecules in water is studied, as a function of droplet size and concentration, amount of copolymer, and nanoparticle volume fraction. The phase diagram is found to be affected, and in particular the percolation threshold characterized by rheology is shifted upon addition of nanoparticles, suggesting participation of the particles in the network. This leads to a peculiar reinforcement behaviour in such microemulsion nanocomposites, the silica influencing both the modulus and the relaxation time. The reinforcement is modelled based on nanoparticles connected to the network via droplet adsorption. Contrast-variation small angle neutron scattering coupled to a reverse Monte Carlo approach is used to analyse the microstructure. The rather surprising intensity curves are shown to be in good agreement with the adsorption of droplets on the nanoparticle surface.
Size-resolved elemental composition of aerosol particles in greater Sydney in 2002–2003

Environmental context Atmospheric aerosols may either scatter or absorb solar radiation, potentially cooling or warming the planet. The warming–cooling effects of aerosols are determined by their optical properties, which depend on chemical composition. To better predict aerosol effects we need a good understanding of aerosol chemistry across a wide size range and geographic area. We report results of a study designed to increase understanding of the chemical composition of fine and coarse aerosols in Sydney. Abstract Between November 2002 and December 2003 samples of PM2.5 and PM10 (particulate matter less than 2.5- and 10-μm aerodynamic diameter) aerosols were collected at four sites in the Sydney Basin in order to determine the spatial and seasonal variation of size-resolved aerosol chemical composition in the Sydney region and relate this to aerosol optical properties. Accelerator-based ion beam analysis was used to determine the elemental composition and black carbon (BC) was determined using the laser integrating plate method. Aerosol species were determined by multiplying a marker element by a factor based on molecular weight ratios. Mass concentrations at the rural sites were lower than at the urban sites with an average PM2.5/PM10 mass ratio of 0.5–0.6 for all sites although at the urban sites it was 0.2–0.25 in summer. For all sites BC was the dominant element, followed by Na. For the urban sites this was followed by Cl suggesting sea salt and then the soil elements Al and Si. For the rural sites the soil elements Al, Si and Ca were more important than Cl, which was found to decrease away from the coast. Analysis of aerosol species shows that BC accounts for a larger portion of PM2.5 than PM10 and sea salt and sulfate levels are higher in summer than in winter.
Laser speckle imaging for visualization of hidden effects for early detection of antibacterial susceptibility in disc diffusion tests

Rapid identification of effective antibiotic treatment is crucial for increasing patient survival and preventing the formation of new antibiotic-resistant bacteria due to preventative antibiotic use. Currently utilized “gold standard” methods require 16–24 h to determine the most appropriate antibiotic for the patient’s treatment. The proposed technique of laser speckle imaging with subpixel correlation analysis allows for identifying dynamics and changes in the zone of inhibition, which are impossible to observe with classical methods. Furthermore, it obtains the resulting zone of inhibition diameter earlier than the disk diffusion method which is recommended by the European Committee on Antimicrobial Susceptibility Testing (EUCAST). These results could improve mathematical models of changes in the diameter of the zone of inhibition around the disc containing the antimicrobial agent, thereby speeding up and facilitating epidemiological analysis.