Miracle-dz/UniFAR-FTUs huggingface dataset:
Status of study on biological and toxicological effects of nanoscale materials

Because the physical and chemical properties of nanosized materials mostly differ from the existing microsized materials, their potential impacts on human health and the environment will be topics under the serious discussions in press and in a number of international scientific journals. We analyze and summarize the existing data of the experimental study on the biological activities and adverse effects of nanoscale materials/particles including single wall carbon nanotubes, multi wall carbon nanotubes, titanium oxide and iron powders. Though some biological behaviors of nanoscale materials observed cannot be understood on the basis of the current knowledge, as the existing data are mostly preliminary, it is too early to make some exclusive conclusions on biological activities (or the toxicity) of any of nanoscale materials. The experimental techniques, the current topics, and the future research directions for this new research field are also discussed.
Origins of the solvent effect on the propagation kinetics of acrylic acid and methacrylic acid

In this study, the relative rate of polymerization of acrylic acid (AA) versus methacrylic acid (MAA) and the effect of water on the polymerization kinetics are investigated within a combined static and molecular dynamics set of computa- tional tools. Experimentally the relative rate of propagation of AA versus MAA is around 35 in bulk and 31 in water. Classical Molecular Dynamics calculations have been carried out to determine the location of the solvent molecules in the proxim- ity of the dimeric poly(AA) and poly(MAA) units. A combined implicit/explicit solvent model was used for the evaluation of the kinetics of the dimeric polymer chains. We show that the rate acceleration of both polymers in water is mainly due to entropic rather than electrostatic effects and is in agreement with experimental findings. Moreover the slower propagation rate of MAA versus AA is ascribed to additional steric effects present in MAA due to the methyl group at the a position of the monomer. Among the functionals used, the M06-2X/6- 311þG(3df,2p)//B3LYP/6-31þG(d) methodology reproduces the experimental rate constants quantitatively the best. V C 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2024-2034
A selective and sensitive phthalimide-based fluorescent probe for hydrogen sulfide with a large Stokes shift

A phthalimide-based fluorescent probe for hydrogen sulfide has been developed with high sensitivity and excellent selectivity. Upon treatment with hydrogen sulfide, this probe displays a strong fluorescence enhancement (196-fold) with a large Stokes shift (105 nm). Moreover, the potential application of using this probe in biological systems has been demonstrated by imaging hydrogen sulfide in living cells.
Hansch analysis 50 years on

The invention of quantitative structure–activity relationships (QSAR) launched the use of computers to understand the multiple factors that contribute to the relationship between the chemical and biological properties of molecules. The original Hansch–Fujita QSAR continues to be performed to this day, fifty years since its inception. In addition, it has inspired vigorous research that has inspired many related methods: for example, methods that use descriptors such as substructures or three‐dimensional features or methods that are based on mathematical models such as partial least squares or recursive partitioning. The influence of QSAR is felt in the recognition of the value of predictions from such models by regulatory agencies and by the widespread use of octanol–water log P in agricultural, environmental, and medicinal chemistry.
Extraction of trace elements in coal fly ash and subsequent speciation by high-performance liquid chromatography with inductively coupled plasma mass spectrometry. Plenary lecture

The speciation of arsenic in coal fly ash is reported. The amounts of AsIII and AsV were found and these values, released into water from coal fly ash, are dependent on the pH of extracted solution and the type of coal fly ash (e.g., location collected, type of coal and combustion conditions). A small amount of arsenic conversion from AsIII to AsV was found, especially from the lower pH extractions. The arsenic conversion may be caused by co-existing high oxidation states elements in the extracted solution, and may be promoted by the grinding process. Oxygen from the atmosphere was found to be an unlikely source for the arsenic conversion. A preliminary investigation for speciation of vanadium and nickel in coal fly ash shows that VV, VIV and NiII exist in the extracted solutions. This extraction–speciation approach can provide some basic information for predicting the hydrolytic behaviour of trace elements in the coal fly ash–water systems and can be extended to the speciation of other elements.
Light management in thin film silicon solar cells

Thin film silicon is an attractive and versatile material for photovoltaics whose manufacturing reached a high level of maturity. Owing to its moderate efficiency compared to crystalline technologies, it should target either power plants with low installation cost or applications with added value like building-integration. Since the technology relies on very thin films of a weakly absorbing material, light-management is, and always has been, a key aspect of the technology. In this review, we briefly describe the class of materials that is summed up under the name “thin film silicon”, point out requirements on device design, and discuss functionalities that enhance the absorption in the silicon films, addressing both their theoretical understanding as well as experimental realization.
Stabilization of Mineral Suspensions by Guar Gum in Potash Ore Flotation Systems

The adsorption of guar gum on illite and dolomite was studied as a function of polymer concentration and ionic strength. The adsorption results were correlated with colloid stability of aqueous suspensions of these two minerals. The adsorption density of guar gum on illite was not affected by the ionic strength of the system. Guar gum adsorption on dolomite was found to strongly decrease at higher electrolyte concentrations. Low concentrations of guar gum brought about flocculation of the minerals while higher dosages led to steric re-dispersion. Results presented here are compared with previously published results for carboxymethyl cellulose (Pawlik et al., j. Colloid Interface Sci. 260, 251-258 (2003)).
Improved method for the complete separation of gross alpha and beta in drinking water

During this work, a modified methodology for the separation of gross alpha and beta activity from potable water was established. Complete separation of gross alpha activity was carried out by Fe(OH)3 and BaSO4 precipitation whereas gross beta activity was scavenged by Ca-oxalate and AMP (ammonium molybdate phosphates). The validation of the results was carried out by laboratory spiked experiments, which show a recovery of gross radioactivity in the range of 90–98% with the new methodology. The detection limits using this methodology are 20 mBq/l and 2 mBq/l for gross beta and alpha respectively. These detection limits are two orders of magnitude lower than the maximum acceptable concentration as prescribed by World Health Organisation (WHO) of gross alpha and gross beta activity i.e. less than 0.1 Bq/L and 1 Bq/L, respectively.
Coupling Thermodynamic Theory with Measurements to Characterize Acidity of Atmospheric Particles

The reference method currently being used in community health studies to characterize the acidity of atmospheric particles is based upon measuring the pH of aqueous extracts of atmospheric particles collected on filter media. These measurements represent total extractable acidity, i.e., hydrogen ion concentration at sufficient dilution of the sample, rather than the actual acidity of airborne particles. In contrast, models based upon chemical equilibrium theory can be used to estimate the hydrogen ion concentration and water content of atmospheric particles from the observed concentration of major solutes (sulfate, nitrate, chloride, ammonium, and sodium). Using about 100 data points from an intensive measurement study in Uniontown, Pennsylvania during 1990, we examined the nature and the causes of the deviations between measured and estimated hydrogen ion concentrations. We found that the measured hydrogen ion concentrations were substantially higher than the estimated concentrations because dilution of .
The Cotton-Mouton effect in gases: Experiment and theory

When polarized light passes through a material in the presence of a strong magnetic field, birefringence is observed. This is known as the Cotton-Mouton effect. Owing to the increasing sophistication of both experimental and computational techniques, this particular aspect of magneto-optics has been investigated increasingly in the last few years. In this review the basic facts concerning both experiment and theory are discussed and tables summarizing all currently known gas-phase data are presented.
Polyoxazoline auf fettchemischer Basis

A new, economic techniques was developed for the production of 2-alkyl-2-oxazolines with saturated, unsaturated or OH-functionalized alkylrests. In the process the fatty acids are changed into polymerizable monomers. The cationic polymerization of fattyalkyl-2-oxazolines was investigated in unpolar solvents and in bulk. It reacts in a living mechanism. The polymerization is remarkable inert against impurities like water or ethanolamide. A reaction enthalpy of ΔH= 85,9 kJ/mol was found for the bulk polymerization of 2-pentadecyl-2-oxazoline
Can cooperativity in hydrophobic association be reproduced correctly by implicit solvation models

The potential of mean force (PMF) of the hydrophobic association of pairs and triplets of nonpolar solute molecules with various sizes and strengths of van der Waals interactions has been studied by means of umbrella-sampling molecular-dynamic simulations combined with the weighted-histogram analysis method. The TIP3P water model was used in these computations. It was found that the distance dependence of the PMF, including the three-body (cooperative) contribution, is described qualitatively correctly by the variation of either the molecular surface area or the excluded solvation-shell molecular volume with the distance between the solute molecules, while the solvent-accessible surface and the hydration-shell models, which are commonly used in mean-field solvation approaches, give an incorrect distance dependence and the wrong sign of the cooperative contribution. The cooperative contribution to the PMF increases the strength of hydrophobic interactions and increases with the size of the solute. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem 88: 41–55, 2002
Chemical and Biological Leaching Methods to Remove Heavy Metals from Sewage Sludge: A Review

The removal of heavy metals (HMs) in sewage sludge (SS) is important since sludge is often disposed or applied on farmland to enhance soil fertility. The present study reviewed two conceptual approaches (chemical and biological leaching) of removing HMs present in SS. In the chemical leaching method, traditional acid treatment together with novel methods such as aeration, complexation and sequential extraction procedure have been reviewed extensively. Certain factors influence the removal of HMs in SS. These factors include; pH, leaching agent, redox potential, and contact time. Nitric acid (HNO 3 ), hydrochloric acid (HCl), sulphuric acid (H 2 SO 4 ), phosphoric acid (H 3 PO 4 ), ethylenediamine tetraacetic acid (EDTA), as well as Thiobacillus thiooxidans and Thiobacillus ferrooxidans are the most widely studied leaching agents and substrates involved in the chemical and bioleaching processes. However, the bioleaching process has been proposed as a safe, efficient, economical, environmental friendly method to remove HMs in SS due to its simplicity, high yield of metal extraction, low acid consumption, and low sludge solids concentration. Nevertheless, the present review has noted that most researchers are of the opinion that more studies are needed in the bioleaching method in order to enhance its commercial attraction.
CONCEPTUAL MODELING OF AIR SPARGING FOR GROUNDWATER REMEDIATION

This paper presents a conceptual model incorporating the findings of a comprehensive laboratory experimental program to serve as a basis for the development of a predictive mathematical air sparging model. The laboratory experiments demonstrated that the zone of influence is parabolic in shape. The hydraulic conductivity and tortuosity of the soil will affect the size of the zone of influence; larger zones of influence will result in soils with lower permeability and greater tortuosity effects. Additionally, localized heterogeneity as well as the presence of layers of soil with differing permeability can adversely affect air flow. Within coarse soils, air will flow in bubble mode; while in finer soils, air will travel in channel mode. Whether in bubble or channel mode, air flow will be greater in the vicinity of the well than at the edges of the zone of influence. Volatilization will always play a dominant role in air sparging remediation; it must be modeled as a nonequilibrium process. Adsorption, both at the microscale and the macroscale level, is only important in soils with sizeable organic or clay fractions, and it is best to model it using a nonequilibrium kinetic model. Depending on subsurface conditions, a modified version of the Monod kinetics model may be used to account for biodegradation; however, if biodegradation is shown to be insignificant, it may be neglected from the model. Dissolution must be considered to assure the contribution of trapped NAPL-phase contamination as a source of contaminant tailing. Advection and dispersion, both macro-scale processes, may be modeled using a form of the advection-dispersion transport equation. Finally, almost as important as volatilization, both macroscale and microscale diffusion based on Fick's Second Law must be included to account for it as a rate-limiting factor.
Solidification of spent radioactive organic solvent by sulfoaluminate and Portland cements

The solidification of simulated spent radioactive organic solvent, tri-butyl phosphate/kerosene, was investigated by emulsification–solidification method using sulfoaluminate cement (SAC) and Portland cement (PC). Zeolite, calcium hydroxide and MR-1 type emulsifier were mixed into the cement blends for improving the performance of solidified waste forms (SWF). The properties of SWF were evaluated in terms of mechanical strength, leachability and mineral phase analyses. The hydration products of SWF were characterized by X-ray diffraction (XRD). The experimental results showed that the 28 d compressive strengths of SAC solidified waste forms (SACF) and PC solidified waste forms (PCF) were 14.23 and 19.07 MPa, respectively. Leaching sequence of three radionuclides in two kinds of SWF is Cs+ > Sr2+ > Co2+. Compared with PCF, SACF had better performance in preventing nuclides Co2+ and Cs+ from leaching to the environment. The XRD patterns suggested that simulated spent radioactive organic solvent and emulsifier in SWF did not obviously change the hydration products of the two cements (SAC and PC).
Storage and Hot Water Treatments on Poststorage Quality of Mango Fruit (Mangifera indica L.) Variety Copania

Tropical fruits such as mangoes destined for export are commonly required to have thermal treatments against invasive pests, to prolong shelf life and preserve fruit quality to fulfill the consumers and markets demand. The effect of storage and hot water treatments were applied to Copania mango fruits (as export cultivar) on physical and biochemical quality were investigated at the seasons of 2008 and 2009. Mature Copania mango fruits were stored at 10, 13 and 25±2 ° C with 90- 95% relative humidity. Other mangoes were also subjected to hot water dipping (HWD) at 46 or 50 o C for 10 min., cooled, and then stored at 10 o C as shipping simulation for 28 days. Fruit quality characteristics i.e. fresh mass losses, decay incidence, fruit firmness, CO2 production (respiration rate), Soluble solid content (SSC), titratable acidity (TA), and ascorbic acid content, were evaluated periodically at after a simulated retail stage of 7 days for 4 weeks. Among different treatments, fresh losses percentage was lower in fruit treated with HWD treatments as compared to storage temperature which having higher percent. There was no evidence of decay was apparent during three and two weeks of storage at 8, 10 and 13°C. Meanwhile, fruits dipped in hot water at 48 and 52 o C for 10 min had no decay percent at 10 o C of storage for three weeks. Although, storage at 8 o C was more effective in keeping fruits firmer after 28 d, Mangoes dipped in hot water at 52°C for 10 min showed firmer fruits than those dipped at 48°C. Moreover, the differences between ST and HWD treatments were significant and the results may indicate that respiration rate of ST were higher than that in HWD during storage period. While, storage treatments increased the total soluble solid content, minor differences were observed after HWD in this concern. TA was found to be lower in mango fruits treated with hot water treatments compared with stored fruits at 8,10 and13 o C. In addition, significant decrease in ascorbic acid content was observed during storage period at 8, 10 and13 o C, as well as hot water treatments at 48 and 52 o C. compared with a sharp reduction in control fruit kept only at 25 o C. after 2 ed week of storage period. From these results it can be concluded that the thermal properties of mango flesh was influenced by the temperature and storage time. There is a relationship between thermal properties and the decay and chilling injury. The quality of mango fruits during export was greatly improved by hot water dipping treatments as quarantine against invasive pests for expanding the market and shelf life duration.
Cu underpotential deposition on Au controlled by in situ Spectroscopic Ellipsometry

We have studied Cu electrodeposition on well defined Au films using real time Spectroscopic Ellipsometry (SE). SE allows to discriminate the under-potential (UP) and over-potential (OP) regimes. In the UP regime, tiny yet reproducible variations of Ψ and Δ parameters indicate the formation of two phases with slightly different optical behavior. The phase at the largest coverage is assigned to a Cu monolayer. The SE response in the OP regime shows a marked dependence on the potential scan rate. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of Sulfur and Iron on Enzymatic Activity and Chlorophyll Content of Mungbean

ABSTRACT A field trial was conducted at Rajasthan Agricultural University, Bikaner, India, in the summers of 2002 and 2003 to determine the effect of sulfur (S) in improving iron (Fe) nutrition of mungbean (Vigna radiata L.) grown on calcareous soils. The experiment was laid out in a split-plot design with three replications. Four levels of sulfur (0, 20, 40, and 60 kg S ha−1) were applied in main plots. In sub-plots, eight levels of Fe were replicated. Three levels of Fe were applied as a basal application of FeSO4 (0, 12.5, and 25.0 kg FeSO4 ha−1) and the remaining five were applied as a foliar application of 0.5% FeSO4 at branching, flowering, and at both branching and flowering with or without 0.1% citric acid. The results of the experiment revealed that application of sulfur at the higher doses had a significant positive effect on activities of catalase, ascorbate peroxidase, guaiacol peroxidase, synthesis of chlorophyll, and active Fe content of green leaves compared with lower doses. Application of 0.5% FeSO4 and 0.1% citric acid at both branching and flowering had no effect. The best results were recorded with basal application of 25.0 kg FeSO4 in combination with 40 kg S ha−1. The frequency of foliar application had an appreciable effect on chlorophyll synthesis, enzymatic activities, and active Fe content in green leaves. Plants that received foliar application of 0.5% FeSO4 + 0.1% citric acid at both branching and flowering responded more than those that received treatment at either branching or flowering. For best results, it is suggested to use 25.0 kg FeSO4 ha−1 in a basal application along with 40 kg S ha−1, as plants require most of their S and Fe at the early growth stages.
Order and Disorder in Powder Mixtures: Spatial Distribution Functions as Tools to Assess Powder Homogeneity

In interactive mixtures with small carrier particles, the content variability is often higher than predicted by available models despite the significant degree of interaction visualized with Scanning Electron Microscopy (SEM). The present work details how pair‐correlation functions can be used to reveal information about the spatial distribution of mixture constituents and their interactions. SEM pictures of a 2 % w/w oxazepam/sodium starch glycolate (SSG) mixture were recorded (n = 14). The constituent coordinates were extracted and pair‐correlation functions as well as the cross‐correlation function were calculated. A significant degree of interaction was observed between the constituents in the experimental mixture, compared to a randomized control system. In particular, the probability of finding an oxazepam particle was especially high inside the perimeter of the carrier particle and along its edges. The observed cross‐correlation between oxazepam and SSG particles was periodic and repeated at distances corresponding to 1–1.5 carrier diameters. It was concluded that interactive mixtures of powders can be compared to disordered/amorphous solids since both exhibit short‐range order, whilst lacking long‐range translational periodicity.
Toxizität von Graphenoxid: Endoperoxide als Ursache

Potentielle biomedizinische Anwendungen von Graphenoxid (GO), z. B. als Trager von Biomolekulen, Reagentien fur die photothermische Therapie oder Biosensoren, werden durch die Zytotoxizitat und Mutagenitat dieses Materials eingeschrankt. Es wird davon ausgegangen, dass diese Eigenschaften zumindest zum Teil auf eine von GO verursachte Erhohung des oxidativen Stresses in Zellen zuruckzufuhren ist. Es ist jedoch nicht bekannt, auf welchen chemischen Fragmenten dieser ungunstige Effekt beruht. In dieser Arbeit wurden vier GOs entwickelt, welche verschiedene redoxaktive Gruppen wie Mn2+, C-zentrierte Radikale sowie Endoperoxide (EPs) auf der Oberflache besitzen. Der Vergleich der Fahigkeit der Materialien, reaktive Sauerstoffspezies in humanen Gebarmutterhalskrebszellen zu generieren, zeigt, dass EPs eine entscheidende Rolle im GO-induzierten oxidativen Stress spielen. Diese Ergebnisse konnen fur die gezielte Entwicklung von biokompatiblem und nicht-toxischem GO fur biomedizinische Anwendungen verwendet werden.
Tailored Mesoporosity Development in Zeolite Crystals by Partial Detemplation and Desilication

Partial detemplation of zeolites followed by desilication in alkaline medium is demonstrated as a powerful and elegant approach to design hierarchical zeolites with tailored degree of mesoporosity. This achievement, illustrated for large beta crystals, is based on the fact that the template‐containing zeolite is virtually inert to Si leaching upon treatment in aqueous NaOH solutions. Partial removal of the structure‐directing agent creates regions in the crystal susceptible to mesopore formation by subsequent desilication, while template‐containing regions are protected from silicon extraction. Variation of the calcination temperature in the range 230–550 °C determines the amount of template removed and enables control of the extent of mesopore formation in the zeolite (20–230 m2 g−1) upon alkaline treatment. The functionality of the introduced mesoporosity in the hierarchical beta crystals is demonstrated by the improved performance in the catalytic pyrolysis of low‐density polyethylene. The partial detemplation–desilication treatment enhances the tuning options of this demetallation method.