Search

An efficient and convenient approach for the preparation of functionalized 2-(methylsulfonyl)pyrimidine derivatives has been developed through cyclic condensation of malonate derivatives with S-methylisothiouronium sulfate followed by derivation and oxidation in water-acetone mixture using oxone as the oxidant. This synthetic strategy provides an efficient and environmentally friendly approach for easy access to 2-(methylsulfonyl)pyrimidine derivatives with considerable yields. [ABSTRACT FROM AUTHOR]

The photochemical degradation of two azo and two anthraquinonic dyes was performed using potassium peroxymonosulphate (Oxone®) activated by UV radiation. The fast decolourization of all dyes was observed within 6 min of UV irradiation, with corresponding dye decays higher than 80%. The kinetic rate constants of the dyes' decay were determined, along with the energetic efficiency of the photochemical treatment, taking into account the influence of a few anions commonly present in real wastewaters (i.e., chloride, nitrate, carbonate/bicarbonate and phosphate ions). Chloride and carbonate/bicarbonate ions enhanced dye degradation, whereas phosphate ions exerted an inhibitory effect, and nitrates did not have a predictable influence. The dye decolourization was not associated with efficient mineralization, as suggested by the lack of a significant total organic carbon (TOC) decrease, as well as by the low concentrations of a few detected low molecular weight by-products, including nitrate ions, formaldehyde and organic acids. High molecular weight by-products were also detected by mass spectrometry analysis. The investigated process may be proposed as a convenient pre-treatment to help dye degradation in wastewater during combined treatment methods. [ABSTRACT FROM PUBLISHER]

Spontaneous imbibition (SI) is one of the most important mechanisms in reservoir engineering. In order to activate of this mechanism completely in carbonate reservoirs, wettability of these oil wet rocks should be altered to water-wet. Multi-step spontaneous imbibition tests were designed and conducted in this study. Results indicated that mixture of smart water and nano silica could increase oil recovery up to 5 percent. Effect of acid number of crude oil on oil recovery of this mixture was investigated by using three samples of crude oil during SI tests: A (0.38 mg KOH/g), B (0.25 mg KOH/g) and C (0.18 mg KOH/g). Maximum oil recovery of SI tests was recorded for oil sample C which had lowest acid number. Ion analysis of imbibing fluids indicated sharp reductions in concentration of sulfate ion in each step of SI tests which confirmed occurrence of ion exchange mechanism in the rock surface of core samples. [ABSTRACT FROM PUBLISHER]

Analysis of microbial community structure of a low sulfate oil producing facility in Nigeria using 16S rRNA gene sequencing technique revealed dominance of oil degrading and nitrate reducing bacteria and methanogenic archaea in produced waters and oil samples namely,Marinobacter(37%),Azovibrio(21%),Thauera(10–28%), andMethanolobus(22%). On the contrary, the associated oil pipeline samples revealed massive dominance of potentially corrosiveMethanolobus(60%) andMethanobacterium(25-27%). Further experimentation shows that the methanogens implicated in oil pipelines are corrosive moderate halophile that utilizes H2/CO2and methanol as substrates. More emphasis should therefore be on methanogenic archaea as opposed to sulfate reducing bacteria (SRBs) during mitigation plans for microbially induced corrosion (MIC) in a low sulfate oil producing facility. [ABSTRACT FROM PUBLISHER]

A polymer–salt aqueous two-phase system based on polyethylene glycol and sulfates was applied to explore the partition behavior of spiramycin. Binodal curves were measured by the turbidimetric titration method. The influence of temperature, salt concentration, and pH on the distribution behavior was investigated in detail by determining the partition coefficient and extraction efficiency. As pH and salt concentration increase, the partition coefficients increase accordingly. It was found that pH displays a significant influence on the partition behavior. The partition coefficient and extraction efficiency can reach 42.46 and 97.8%, respectively, at pH 9.0 and 15.80% (w/w) salt concentration. [ABSTRACT FROM AUTHOR]

The present work characterizes the spatiotemporal variations of air pollution at four sites in Xi'an city. The investigations lasted for 1 year: January 1 through December 31, 2015. The concentrations of CO, NO2, O3, PM and SO2 were systematically monitored. The gray correlation analysis was used to correlate PM2.5 and gaseous pollutants. The formation mechanisms of sulfate and nitrate aerosols were discussed. Results clearly revealed severe air pollution by PM2.5, PM10 and NO2 at all four sites. Significant monthly variations were observed for PM2.5, PM10, SO2 and CO with the maximum values in December/January and minimum values in June/July. The O3 level showed an opposite trend. Spatially, high variations were observed for PM and some gaseous pollutants at individual sites. Gray correlation analysis revealed the significance of various major influencing factors on seasonal PM2.5 values at each site. In general, PM10, SO2 and NO2 affect the PM2.5 more than other pollutants. For a more efficient control of air pollution, a systematic spatial characterization of the seasonal variability of individual influencing factors is necessary. [ABSTRACT FROM AUTHOR]

External Sulphate Attack on sulphate-resisting Portland cement concretes is a well-researched field. However, the effect of temperature on the performance of sulphate attack requires further attention. For this purpose, cubic mortars were made with sulphate resisting Portland cement (low C3A) and two types of sand, silica and limestone, which were then immersed in a 5% MgSO4solution at different temperatures: 5, 20 and 50 °C, for 24 months. The deterioration of mortars due to magnesium sulphate attack was evaluated by measuring changes in mass, compressive strength, porosity and sorptivity. The X-ray diffraction was also used to determine the different mineral phases, and the pH of the conservation solutions was monitored. No damage was observed on the samples exposed at 50 °C. However, serious damage was noted on mortars made with silica sand exposed at 5 °C. Results show that high temperature improved some physical and mechanical properties and do not necessarily accelerate the degradation due to magnesium sulphate attack. Sulphate-resisting Portland cements with limited C3A content was found to be susceptible to Thaumasite Sulphate Attack. The type of sand has a remarkable effect on the performance of mortars at low temperature compared to high temperature. The samples with limestone sand showed better resistance against magnesium sulphate attacks. [ABSTRACT FROM PUBLISHER]

Separation of cobalt and nickel from sulfate media was investigated, using a extraction system of 30% 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (P507)+15% trioctyl/decylamine (N235)+55% sulfonated kerosene. About 41 wt% Co2+was extracted with 1.6 wt% co-extraction of Ni2+at O/A ratio of 2:1. Scrubbing of Ni2+and stripping of Co2+could be achieved from the loaded organic phase, using water and 0.05 mol/L H2SO4, respectively. Cobalt extraction percentage decreased with increasing Mg2+concentration, but this influence was negligible as [Mg2+] < 0.1g/L. The favorable equilibrium pH was 4–4.8. A different E-pH curve was observed in the P507-N235 system compared to the saponified P507 system. [ABSTRACT FROM AUTHOR]

Adsorption of Sc onto two chelating resins, aminomethyl phosphonic (TP 260) and iminodiacetate (TP 209), and one solvent impregnated resin with bis(2,4,4-trimethylpentyl) phosphinic acid (TP 272) was investigated. Resin capacities, ion selectivity, adsorption kinetics, and equilibrium isotherms were measured. Sc speciation was predicted using chemical thermodynamic data. The kinetic data were fit to empirical models. The adsorption behavior was established by fitting equilibrium data to Langmuir and Freudlinch isotherms. Process variables such as pH, sulfate concentration, and temperature were considered. This new information will be used for hydrometallurgical process selection for Sc recovery. [ABSTRACT FROM PUBLISHER]

Mercury (Hg) transport and methylmercury (MeHg) production in riverbank sediments are complex processes influenced by site-specific physical and biogeochemical conditions. The South River watershed in VA, USA, contains elevated concentrations of Hg in riverbank and floodplain sediments, which has the potential to methylate. The role of specific organic carbon sources in promoting methylation reactions in natural sediments under dynamic flow conditions is not well understood. Four saturated column experiments were conducted, including a control column, which received South River water as an influent solution, and three columns that received South River water amended with: acetate (5.8 mM); lactate (5.7 mM); and lactate (5.7 mM) with SO42−(10.1 mM). The amendments were selected to promote growth of different microorganisms to gain an understanding of the microbial processes, controlling rates of methylation. The column receiving lactate and SO42−had the highest MeHg concentrations in the effluent and in the pore water near the effluent at 1.8 and 4.9 μg L−1, respectively. At the cessation of the column experiments, the lactate–sulfate column sediments contained the highest populations of enumerable sulfur-reducing bacteria and the highest solid-phase MeHg at 530 ± 100 ng g−1dry wt. from the interval closest to the influent. The results suggest that the form and availability of electron donors and acceptors are primary factors controlling rates of methylation in the South River sediment. [ABSTRACT FROM AUTHOR]

It has been conjectured that if sulfur in the fuel is removed, engine materials will cease to experience attack from hot corrosion since the fuel sulfur has been viewed as the primary source that has caused hot corrosion and sulfidation. Hot corrosion has been defined as an accelerated degradation process that is generally considered to involve deposition of corrosive species (e.g. sulfates) from the surrounding environment (e.g. combustion gas) to the surface of hot components, followed by subsequent destruction of the protective oxide scale. Most papers in the literature since the 1970s consider sodium sulfate as the single salt causing hot corrosion. There has been a push to remove fuel sulfur content to less than 15 ppm. However, sulfur species may still enter the combustion chamber via air intake or with seawater entrained in the air through the air intake of the ship. Seawater contains, in addition to sodium sulfate, magnesium, calcium, and potassium salts. Additionally, sulfate speciation and the content of atmospheric particulate matter (PM) varies considerably around the world and in some places, such as China and India, high PM seems to cause an increased risk of deposit-induced hot corrosion due to atmospheric pollutants rather than a combustion process (i.e. sulfur impurity in the fuel). The increasing operating temperatures of turbine engines and activities within regions of the world that have relatively high pollutant (PM, SO2, C, Ca, etc.) levels are working conjointly to cause previously unobserved forms of high-temperature corrosion. This paper will cover some of our revised understanding of hot corrosion and consider other possible contaminants that could further complicate our understanding of hot corrosion. [ABSTRACT FROM AUTHOR]

This study was aimed at identifying the organic molecules oxidising the Cu–Sn alloy coating in a sulphate electroplating bath to form a black solar absorbing surface. For this purpose, 20 organic chemicals were used separately in the electroplating bath to obtain Cu–Sn alloy thin films. The films were characterised using the spectroscopic methods. It was found that addition of EDTP (N,N-dimethyl-dithiocarbamylpropyl sulphonic acid, sodium salt) provided the best optical parameters. [ABSTRACT FROM PUBLISHER]

Cleaning and disinfection of dairy equipment is essential to ensure the hygienic quality of milk. Occasionally, some farmers use washing-up liquids and disinfectants for home use, especially when cleaning procedures are carried out manually. Residues of detergents and disinfectants in milk may interfere with the response of microbial inhibitor tests used for screening antibiotics in milk. Therefore, the aim of this study was to evaluate the interference of non-specific detergents in screening tests (BRT MRL; Delvotest SP-NT MCS; Eclipse 100) for goat's milk. Twelve replicates of eight concentrations of five washing-up liquids (0–1%) and one disinfectant (0–1%) were analysed. The results showed that the presence of washing-up liquids at concentrations of ≥1 ml/l leads to positive results in microbial tests. In particular, the product containing sodium laureth sulphate and ethanol produced the largest number of positive outcomes. The presence of disinfectant based on sodium hypochlorite did not affect the test response. The detection capabilities of microbial inhibitor tests for penicillins were also studied in milk with and without cleaning products, calculating the dose–response curve with eight concentrations of amoxicillin, ampicillin, benzylpenicillin and cloxacillin, respectively. The detection limits of the screening tests for penicillins were not modified substantially by the cleaning product based on sodium laureth sulphate and ethanol. Residues of cleaning agents in milk can be avoided when specific detergents and disinfectants for milking equipment are used and good cleaning practices are applied. [ABSTRACT FROM PUBLISHER]

A fully ionized polyelectrolyte was synthesized for Cr(VI) removal from aqueous solutions by continuous polymer enhanced ultrafiltration (PEUF). Effect of operating parameters such as pH, loading, polymer, and competing ion concentrations were examined. Highest Cr(VI) retention was obtained at a loading of 0.01 at pH 4. Increasing both polymer and chromate concentrations at a fixed loading of 0.01 decreased the retention which demonstrated the effect of crowding. In the presence of competing anions such as chloride and sulfate, Cr(VI) retention decreased for all of the pH values studied. Even at high competing anion concentrations, significant retentions of Cr (VI) were obtained. [ABSTRACT FROM AUTHOR]

The effect of higher quaternary ammonium salts’ (QAS) exchange center steric accessibility and doubly charged hydrophilic inorganic ions size on the analytical characteristics of S4O62−, SO42−, SO32−, S2−, S2O32−ion selective electrodes (ISEs) was studied. It has been established that for SO42−, SO32−, S2−, S2O32−- SE with the improvement of the exchange center steric accessibility in the series TNODA - TB - TE - TM - BHPBTM - (oxyethyl)2TM - (oxyethyl)3TM - (oxyethyl)4TM the selectivity coefficients lgKPot(i, j) decrease significantly. The LDL reducing magnitude and selectivity improvement depends from doubly charged anion size and decreases in series S2−-SO32−-SO42−-S2O32−ions. The maximum effects are achieved for the smallest S2−ion. For S4O62−-SE an inverse relationship is found, i.e. as the steric availability decrease in the QAS series (oxyethyl)4TM -(oxyethyl)3TM - (oxyethyl)2TM - BHPBTM - TM - TE - TB - TNODA - TOD a certain improvement in analytical characteristics is observed. [ABSTRACT FROM AUTHOR]

Objective: Antenatal magnesium sulfate (MgSO4) is recommended for fetal neuroprotection. The aim of this animal study was to assess the neuroprotective effect of in utero exposure to MgSO4, under inflammatory conditions.Methods: Timed pregnant Sprague-Dawley (SD) rats (n = 29) received four intra-peritoneal (IP) injections of lipopolysaccharides (LPS; 200 μg/kg), combined with increasing concentrations of MgSO4 (25, 50 or 100 mg/kg, n = 19) or saline solution (SS; n = 10). In the second set of experiments, animals (n = 8) received a single IP injection of i) LPS (500 μg/kg), MgSO4 (50 mg/kg) and SS (n = 4) or ii) LPS (500 μg/kg), MgSO4 (50 mg/kg) and IL-6 (12 μg/kg) (n = 4). Neurodevelopmental outcomes of surviving pups (n = 212) were assessed by the open field and the rotarod tests.Results: Pups' average weight at postnatal day (P) 25 was 75.77 g and 89.08 g in MgSO4 and control groups, respectively (p = 0.02). Pups in MgSO4 group have traveled a shorter distance and have shown reduced motor balance and coordination (p < 0.01). Average weight of pups receiving (LPS + MgSO4+ IL-6) was 92.26 g at P25, compared to 75.86 g in (LPS + MgSO4+SS) group (p < 0.05).Conclusions: In our model, MgSO4 induces pup's growth retardation and motor deficits, which may partly be related to a lower IL-6 circulating concentration. [ABSTRACT FROM AUTHOR]

The removal of Indigo Carmin (IC) and Congo Red (CR) dye mixtures using layered double hydroxide (LDH) (modified with sodium dodecyl sulfate (SDS)) has been studied. In the experimental context of this study, LDH was synthesized under a nitrogen atmosphere at room temperature using the coprecipitation method and characterized by Fourier transform infrared specroscopy (FTIR), X-ray diffraction (XRD), energy dispersive analysis of X-rays (EDAX) and scanning electron microscopy (SEM) analyses. Contact time, temperature, and initial dye concentration on the adsorption process have been investigated. Results show that the maximum removal of IC and CR was obtained as about 50% and 95%, respectively. The isothermal data were fitted to Langmuir, Freundlich, and Temkin adsorption isotherms. Elovich and other kinetic model equations were applied. Adsorption depended on the starting naphthalene concentration at investigated various temperatures (298, 308, and 318 K) significantly. [ABSTRACT FROM AUTHOR]

Considering the role of glucosamine sulfate (GS) in the biosynthetic pathways of chondrocytes, an attempt was made to design an electrospun poly-3-hydroxybutyrate (PHB) scaffold loaded with GS to develop cartilage tissue engineering. The study was initiated using the optimal electrospun scaffold conditions for the synthesis of PHB/GS. The resulting scaffolds have shown excellent pore architectures and mechanical behavior compared to pure PHB. UV spectrophotometric analysis, for the evaluation of the GS release behavior, showed zero-order kinetics release.In vitroresults indicated excellent cell viability, cell adhesion, and cell penetration of PHB/GS scaffolds compared to pure PHB. [ABSTRACT FROM AUTHOR]

The aim of present study was development and in vitro characterization of sponge like, in situ gelling inserts of terbutaline sulfate by lyophilization for nasal administration to avoid first-pass metabolism. The inserts were investigated for thickness, water uptake, moisture absorption, drug content, in vitro drug release, histopathology, scanning electron microscopy analysis, and powder X-ray diffraction. The developed inserts were smooth in appearance with uniform thickness and drug content. The inserts exhibited satisfactory water uptake and extended drug release up to 10 h. Hence, inserts could be used as a viable alternative to improve therapeutic efficacy of terbutaline sulfate. [ABSTRACT FROM AUTHOR]

The sulphate leach liquor obtained from the sulphuric acid leaching process of Egyptian monazite was treated using solvent extraction to recover U(VI) by LIX63. The influence of various basic variables such as pH, concentration of LIX63, temperature, different stripping agent, phase ratio and diluents was examined. Using 10% LIX63 with the aqueous solution at equilibrium pH 5.5 and a phase ratio A/O = 1/1, a four-stage McCabe-Thiele plot was constructed, which showed 85.57% of U(VI) extraction. The thermodynamic data showed that the extraction process is exothermic with enthalpy change ΔH = − 43.866 kJ/mol, the stripping of U(VI) was quantitative using 4 M HNO3. The stable complex UO2(HSO4)Rorgformed during extraction which supports the cation exchange mechanism was confirmed by FTIR spectral analysis. Uranium cake was finally obtained from the strip solution by the addition of hydrogen peroxide and ammonium hydroxide as precipitating agents, and a workable flowsheet was then formulated. [ABSTRACT FROM PUBLISHER]

Tri-ammonium sodium di-sulphate (NH4)3Na(SO4)2was crystallized by evaporating the aqueous solution at room temperature. The phase transition and the crystal structure at room temperature were studied by means of differential scanning calorimetry (DSC) and single-crystal X-ray diffraction, respectively. As a result, thermal anomalies relating to phase transitions were observed at 224.4 K. At room temperature, (NH4)3Na(SO4)2belonged to the monoclinic space groupP21(Z= 2) and had lattice constants ofa= 5.9991 (4) Å,b= 7.7851 (5) Å,c= 10.6528 (8) Å and β = 90.0000 °. TheRfactor converged to 0.0488. [ABSTRACT FROM PUBLISHER]

We review recent understanding of the crystallographic phases and its relation to ferroelectricity in ammonium lithium sulphate (NH4LiSO4) using the crystal structural data reported before and present our recent idea about its ferroelectricity. In this paper, we also report phase transitions and crystal structure at room temperature of tori-ammonium lithium di-sulphate ((NH4)3Li(SO4)2) from our recent experimental results. NH4LiSO4which is one of the (NH4)2SO4family ferroelectrics and (NH4)3Li(SO4)2which is one of theA3B(XY4)2-type derived from theABXY4-type were crystallized by evaporating the aqueous solution at room temperature. The phase transition and crystal structure were studied by means of thermogravimetric analysis, differential scanning calorimetry and single-crystal X-ray diffraction. In addition, phase transitions and ferroelectricity of NH4LiSO4will be discussed from the crystal structural changes. [ABSTRACT FROM PUBLISHER]

The properties and characteristics of metal oxide and sulfate catalysts with different active elements for selective catalytic reduction of NO with NH3were investigated. Cerium-based oxide catalyst showed the widest temperature window for NOxremoval and manganese-based oxide catalyst exhibited the best catalytic performance at low temperature. For all the catalysts, the SCR activities at low temperature were directly related with the redox abilities of catalysts. The existence of sulfate groups inhibited the redox abilities of active species for sulfate catalysts compared with the metal oxide catalysts. The catalytic activities of CeWTi-S and MnWTi-S were seriously decreased in contrast to CeWTi-N and MnWTi-N. The temperature window of CuWTi-S was shifted toward higher temperature comparing with CuWTi-N. The FeWTi-N and FeWTi-S catalysts both showed high NOxconversion in the temperature range between 300°C and 400°C and N2O concentrations for iron-based samples were least among the same kind of catalysts. The abundance of acid sites and weak stability of surface sulfate groups for iron- and copper-based sulfate catalysts might be the main reasons accounting for the better NOxconversion in the medium-temperature range. [ABSTRACT FROM AUTHOR]

The goal of this research is to structure a hyaluronic acid modified nanostructured lipid carrier (HA-NLCs) for vincristine sulfate (VCR) delivery, and detect its efficiency to improve the oral bioavailability. Emulsion solvent evaporation method was used to prepare the HA-NLCs nanoparticles. The particle size, zeta potential and entrapment efficiency of VCR-NLCs and HA-NLCs were 187 ± 3.52 nm, −8.61 ± 1.29 mV, 33.12 ± 1.16% and 192 ± 4.41 nm, −32.82 ± 2.64 mV, 34.41 ± 2.21%, respectively. HA-NLCs could significantly improve the cellular uptake efficiency and cytotoxicity in MCF-7 cells than other VCR formulations. The expressions of apoptosis related protein Caspase-3, Caspase-9, Bax and Bcl-2 were estimated by western blot assay in MCF-7 cells, and HA-NLCs exhibited the strongest effect in promoting cell apoptosis. The pharmacokinetics of HA-NLCs was evaluated in Sprague–Dawley male rats and the relative oral bioavailability of HA-NLCs and VCR-NLCs was improved about 1.8-fold and two-fold compared with VCR solution, respectively. Therefore, these results indicated that HA-NLCs could significantly improve the oral bioavailability and was a promising vehicle for the oral delivery of VCR. [ABSTRACT FROM PUBLISHER]

The films with the extreme concentration of poly (diallyldimethylammonium chloride)/sodium dodecylsulfate complex spread to the surface of aqueous solutions of formic and acetic acids reduce the evaporation rate of liquids by 3–6% and demonstrate selective properties increasing water content in the vapor by 1–3 abs.%. The concentrations of solutions were up to 30 vol.%. The formation conditions of such films were determined by means of the Wilhelmy plate technique. Surface tension isotherms of aqueous solutions of acids were also obtained. [ABSTRACT FROM AUTHOR]

A new anticoagulant agent was prepared by introducing sulfate groups into corn stover xylan through homogeneous reactions. Three organic solvents,N, N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO) and formamide (FA), were adopted as reaction media, with the assistance of LiCl. Structural characterization by FT-IR and13CNMR showed that xylan sulfate (XS) could be successfully synthesized with SO3∙Pyridine (SO3∙Py) complexes sulfation reagent in the three media. The effect of sulfation temperature, sulfation time, media type and molar ratio of −SO3/−OH on the degree of substitution (DS) and degree of the polymerization (DP) were studied. DMF/LiCl were more effective than DMSO/LiCl and FA/LiCl in preparation of xylan sulfate with high DS. The optimal conditions for sulfation were obtained when SO3∙Py complex was added to DMF/LiCl with −SO3/−OH ratio of 1.5:1 and maintained at 50 °C for 3 h. Degree of polymerization of xylan was decreased during the sulfation process and DMF/LiCl offered the least xylan degradation as compared with DMSO/LiCl or FA/LiCl. Anticoagulant activities of the resultant xylan sulfates with different DS were evaluated by using activated partial thromboplastin time (APTT), thrombin time (TT), and prothrombin time (PT). Results indicated that the introducing of sulfate groups into xylan did endow the polysaccharides with anticoagulant activity. The APTT and TT of XS with DS of 1.20 reached 141 and 45.3 s at a dosage of 20 μg/mL, while the APTT and TT values for the blank sample were only 35.5 and 15.6 s. Furthermore, coagulation time was prolonged with the increase of DS and the concentration of XS. Our findings provide new insights into the value-added utilization of agricultural biomass. [ABSTRACT FROM PUBLISHER]

In this study, we present the associations of fine particle nitrate, sulfate, and four organic carbon fractions with ambient temperature in urban and background monitoring sites in the United States for the 2011–2012 period. Nitrate concentrations increased for decreasing temperatures, while sulfate levels increased for temperatures higher than 14 °C. The profiles of organic carbon fractions for different temperatures were comparable to that observed for elemental carbon, a thermally stable and non-reactive component emitted from combustion-related sources. The trends for all parameters were comparable for the nine regions and independent to emission estimates of fine particles and their precursors. These patterns demonstrated that ambient temperature may manipulate fine particulate composition. These differences may be augmented by rising temperatures due to changing climate. Considering the causal associations between particulate pollution and pulmonary and cardiovascular diseases, changes in the composition of particulate pollution may imply adjustments on the human health impacts. [ABSTRACT FROM PUBLISHER]

[Hg2(L1)2I4] (1), [Cd2(L1)2I4] (2), {[Cd(L1)2(SO4)(H2O)]·4H2O}n(3), {[Zn2(L2)2(Cl)4]·0.5H2O} (4), {[Cu2(L2)2(SO4)2(H2O)4]·2.5H2O} (5), and {[Cd(L2)2(SO4)(H2O)]·3H2O}n(6), based on N–(3–picolyl)–N′–(3–pyridyl)urea (L1) or N–(4–picolyl)–N′–(3–pyridyl)urea (L2), have been synthesized and characterized by elemental analyses, IR spectra, single-crystal and powder X-ray diffraction, and thermogravimetric analyses. Complexes1and2are isomorphous and feature similar rectangular metal organic loops, which were further extended into 2-D supramolecular structures through hydrogen bonds. Complex3possesses a 2-Dsqlsheet, and the channels between the neighboring sheets are filled with lattice water molecules, which formed a 1-D water tape. Complex4also exhibits a rectangular metal organic loop and a 3-D supramolecular structure with the help of hydrogen bonding interactions. Complex5also possesses a metal organic loop, and the water molecules interacted with sulfates, constructing a 1-D water–sulfate tube. Complex6features a 1-D loop polymeric chain. Moreover, the solid state luminescences of1–4and6have been investigated. [ABSTRACT FROM AUTHOR]

Biodiesel of waste cooking oil origin is gaining attention as a replacement for current fossil fuels, as its low-priced, recycled feedstock shall prevent food source competition, which is estimated to happen with current biodiesel production processes. As a result, waste cooking oil has been claimed to be a highly potential feedstock for biodiesel production. In the present research work, Fe-Mn doped sulphated zirconia catalyst was synthesized and used in simultaneous esterification and transesterification of waste cooking oil to biodiesel synthesis. The catalyst was prepared through the impregnation method and characterized by using XRD, TPD-NH3,FT-IR, BET, and TEM. Response surface methodology (RSM) in conjunction with the central composite design (CCD) was applied to statistically evaluate and optimize the biodiesel preparation process. It was found that the synthesis of biodiesel achieved an optimum level of 97.2% waste cooking oil methyl ester’s (WCOME’s) yield at the following reaction conditions: methanol/oil molar ratio: 10:1, catalyst concentration: 3.0 wt %, and reaction temperature: 160 °C. The extremely high WCOME’s yield of 97.2% was proved to be due to high acidity, surface area, and large pore diameter; reactants can easily diffuse into the interior pore of the catalyst and allow them to be in contact with active sites that enhance catalytic activity. [ABSTRACT FROM AUTHOR]

Lime neutralization is widely used to precipitate heavy metals including copper and cobalt from wastewater. Limestone (calcium carbonate: CaCO3) is too stable to be used directly for this purpose. Grinding of CaCO3in the solutions of copper and cobalt sulphate was conducted to raise its reactivity. During the mechanochemical activation, CaCO3reacted with copper sulphate but not significantly with cobalt sulphate and this phenomenon allowed an easy separation of copper from cobalt. The residual of Cu(II) ions in solution could be controlled at less than 0.1%, meanwhile more than 90% of the Co(II) ions remained in aqueous solution. [ABSTRACT FROM AUTHOR]

Sulfur and oxygen isotope fractionation of elemental sulfur disproportionation at anaerobic haloalkaline conditions was evaluated for the first time. Isotope enrichment factors of the strains Desulfurivibrio alkaliphilus and Dethiobacter alkaliphilus growing at pH 9 or 10 were −0.9‰ to −1‰ for sulfide (34ϵ), +3.6‰ to +4.7‰ for sulfate (34ϵ), and +3.5‰ to +7.7‰ for oxygen in sulfate (18ϵ). These values are significantly smaller compared to previously published values of sulfur disproportionators at neutral pH. We propose that this discrepancy is caused by masking effects due to preferential formation of polysulfides at high pH leading to accelerated internal sulfur turnover rates, but cannot rule out distinct isotope effects due to specific enzymatic disproportionation reactions under haloalkaline conditions. The results imply that the microbial sulfur cycle in haloalkaline environments is characterized by specific stable sulfur and oxygen isotope patterns. [ABSTRACT FROM AUTHOR]

Separation of nickel(II) and cadmium(II) ions with use of ion-exchange resins—Amberlyst 15 and Lewatit OC 1026—supported liquid membranes (SLM), polymer inclusion membranes (PIM) and ion-exchange membranes (IM) from sulphate solution has been studied. Di(2-ethylhexyl) phosphoric acid (D2EHPA) was used as the ion-carrier in PIM and SLM separation. It was shown that use of SLM or PIM membranes enables separation of Ni(II)/Cd(II) ions. Experimental results data show that the highest recovery factor values were obtained for supported liquid membranes. The SEM surface and cross-sectional images of SLM support, polymer inclusion membrane and ion-exchange membrane have been also prepared. [ABSTRACT FROM PUBLISHER]

The article discusses the effect of pollution in human's health. Environmental pollutants like air pollution and sulfur dioxide are among the few mentioned reasons that affects the health of individuals or communities. One chronic effect of sulfur dioxide to human is bronchitis. Several studies showed that exposure to this substance can cause acute respiratory disease, asthma, and cardio-pulmonary disease. However, the aggravated symptoms is said to be most related to suspended sulphates. An overview of the studies conducted by the Environmental Protection Agency is offered.

In this study, enhanced ozonation of estriol (E3) with persulfate (PS) was investigated in aqueous solution. Simultaneous generation of hydroxyl radical (•OH) and sulfate radical (•SO4-) by O3/PS process was proposed and experimentally verified. Kinetic results revealed that the degradation of E3 was affected by the solution pH, PS concentration, O3 dosage and E3 initial concentration. The optimal reaction rate was observed in alkaline solutions. The mechanism for the synergistic effect was preliminarily explored by the addition of hydroxyl and sulfate radical scavengers. The enhanced degradation of E3 by O3/PS was also observed in actual water samples, which provided impetus for practical applications. The degradation intermediates were detected using LC/MS. Results showed that the phenol structures of the estrogens were mostly oxidized to cyclohexenone moieties and quinone-like structures. [ABSTRACT FROM AUTHOR]

A diverse range of nickel-based coatings can be cathodically deposited from a classical Watts electroplating bath containing suitable additives by appropriate control over operational conditions. Modern nickel-based electrodeposits are concisely reviewed and can be seen to be longer-term developments from the publication of optimised conditions for rapid nickel plating from an acid sulphate bath by Watts 100 years ago, in 1916. Recent examples of tribological nickel electrodeposits are illustrated by examples from the authors’ laboratory: (i) low friction, hard, wear resistant surfaces (containing 2-D, layered, self-lubricating particles of Ni–P–MoS2), (ii) superhydrophobic layers of Ni–WS2, showing a lotus petal effect (for self-cleaning surfaces), (iii) light emitting, luminescent signal bearing surfaces of Ni–BAM (BaMgAl11O17:Eu2+) metal oxide, (providing anin-situphosphor wear tracer) and (iv) nanocrystalline surfaces of Ni, Co, Ni–Co and Ni–Co–P (including high surface area electrocatalysts). Important trends in the deployment of the longstanding, versatile Watts nickel electroplating bath are seen to include the development of (a) surfaces having tailored structure, hence special properties, by choice of bath composition and operational conditions, (b) nanostructured composite layers containing mixed inclusions and (c) layers able to diagnose in-service wear and provide an output signal. Subject areas needing further research are suggested. [ABSTRACT FROM AUTHOR]

Selenium and chromium are heavy metals that are highly toxic to living organisms when they are present in excess amounts. The major forms of selenium and chromium in the environment are selenate and chromate, which act as toxic analogs of sulfate in plants, inhibiting its uptake and causing sulfur deficiency. To provide simple and inexpensive means of environmental analysis for selenate and chromate, we previously developed a model system for detecting and quantifying their levels by measuring the accumulation of green fluorescent protein (GFP) in transgenic plants under the control of the sulfur-responsive promoter region of the high-affinity sulfate transporterSULTR1;2fromArabidopsis(PSULTR1;2-GFP). However, the detection limit for both selenate and chromate was 10 μmol L−1, which was higher than the environmental standards. Here, we report a more sensitive monitoring system for selenium and chromium by combiningPSULTR1;2with another sulfur-responsive region of the sulfate transporterSULTR2;1located in the 3ʹ-non-transcribed intergenic region (TSULTR2;1). The fusion gene construct consisting ofPSULTR1;2, GFP andTSULTR2;1(PSULTR1;2-GFP-TSULTR2;1) was introduced intoArabidopsisplants, andPSULTR1;2-GFP-TSULTR2;1transgenic plants showed significant increases in GFP under sulfur-deficient conditions or with the addition of selenate or chromate to the growth medium. The increase in GFP depended on selenate concentration. Overall, the use ofPSULTR1;2-GFP-TSULTR2;1plants decreased the detection limits to 1 and 3 μmol L−1for selenate and chromate, respectively, providing a highly sensitive plant-based system for detecting selenium and chromium in the environment. [ABSTRACT FROM AUTHOR]

The effect of commercially available pharmaceutically active compound amikacin disulfate (AMK) against the corrosion of copper in 1 M HNO3solution was investigated using Tafel polarization, electrochemical impedance spectroscopy (EIS), and weight loss techniques. The results show that inhibition efficiency (IE %) increases with increasing inhibitor concentration from 0.1 to 1.0 mM. Increasing the temperature increased the corrosion rate, and results decreased the inhibition efficiency. The adsorption of inhibitor obeyed Langmuir adsorption isotherm model via physisorption mechanism. EIS technique exhibits one capacitive loop, indicating that the corrosion reaction is controlled by charge transfer process. Polarization measurements showed that the AMK is mixed-type inhibitor. The surface morphologies were studied by scanning electron microscopy and atomic force microscopic techniques. The corrosion mechanism were explained by Fourier transform infrared spectroscopy. [ABSTRACT FROM PUBLISHER]

A novel organic sulfate (C4H16N3)SO4⋅HSO4has been prepared and characterized by single-crystal X-ray diffraction, infrared spectroscopy, thermogravimetric analysis and differential scanning calorimetry (DSC). The structure consists of linked HSO4−and SO42−anions assembled into clusters. Organic triple-protonated diethylene triammonium cations are interconnected to these clusters via N–H−O hydrogen bonds to create the three dimensional arrangement. The Hirshfeld surface and associated fingerprint plots of the compound were presented to explore the nature of intermolecular interactions and their relative contributions to building the solid-state architecture. TG-DTA and DSC studies showed the presence of two phase transitions. Infrared spectrum is reported and discussed on the basis of group theoretical analysis and on Density Functional Theory calculations. [ABSTRACT FROM PUBLISHER]

Inflammation and oxidative stress are common features of patients with chronic kidney disease (CKD) and many uremic solutes retained in these patients could be involved in these processes, among which protein-bound solutes such as indoxyl sulfate (IS). White adipose tissue recently gained attention as an important source of inflammation and oxidative stress. To examine the effect of IS on adipocytes, 3T3-L1 adipose cells were incubated with IS to mimic the conditions encountered in uremic patients. Incubation of adipose cells with IS increased reactive oxygen species production generated mainly through activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase since it was prevented by the NADPH oxidase inhibitor apocynin. Exposure to IS furthermore exacerbated the secretion of tumor necrosis factor-α and interleukin-6 by adipose cells. This inflammatory response was prevented by NADPH oxidase inhibition pinpointing the pivotal role of intracellular oxidative stress. IS induces adipocyte perturbation and promotes inflammatory state mainly through induction of oxidative stress. IS, a uremic toxin, accumulates in CKD patients could, therefore, be an important mediator of adipocyte dysfunction in these patients. [ABSTRACT FROM PUBLISHER]

Highly mineralized springs in the Scuol-Tarasp area of the Lower Engadin and in the Albula Valley near Alvaneu, Switzerland, display distinct differences with respect to the source and fate of their dissolved sulphur species. High sulphate concentrations and positive sulphur (δ34S) and oxygen (δ18O) isotopic compositions argue for the subsurface dissolution of Mesozoic evaporitic sulphate. In contrast, low sulphate concentrations and less positive or even negative δ34S and δ18O values indicate a substantial contribution of sulphate sulphur from the oxidation of sulphides in the crystalline basement rocks or the Jurassic sedimentary cover rocks. Furthermore, multiple sulphur (δ34S, Δ33S) isotopes support the identification of microbial sulphate reduction and sulphide oxidation in the subsurface, the latter is also evident through the presence of thick aggregates of sulphide-oxidizingThiothrixbacteria. [ABSTRACT FROM AUTHOR]

In the present study, ettringite precipitation was theoretically and experimentally evaluated as a means of sulphate removal. The results showed that ettringite precipitation is an effective and reliable method for sulphate removal. Synthetically prepared samples which were simulated to total wastewaters originating from the textile industry (sulphate concentration of 0.06 M) and to dye bath effluent (sulphate concentration of 0.22 M) were subjected to ettringite precipitation using the systems with Na2SO4–AlCl3–Ca(OH)2–NaOH, Na2SO4–AlCl3–Ca(OH)2, and Na2CO3–Na2SO4–AlCl3–Na(OH)2. An equilibrium model involving precipitation more than one solid phase and with ionic strength correction was used to predict the sulphate removal efficiency as well as solution composition. The optimum pH for ettringite precipitation in all systems was found to be around 12.0. By the application of the method, 0.06 M initial sulphate concentration was reduced down to 60 mg/L for synthetically prepared samples and 325 mg/L for real wastewater. For the concentrated samples of 0.22 M initial sulphate, remaining sulphate levels varying between 230 and 280 mg/L were obtained for both synthetic and real wastewater samples. [ABSTRACT FROM AUTHOR]

Microbial organic sulfur mineralization to sulfate in terrestrial systems is poorly understood. The process is often missing in published sulfur cycle models. Studies on microbial sulfur cycling have been mostly centered on transformations of inorganic sulfur, mainly on sulfate-reducing and inorganic sulfur-oxidizing bacteria. Nevertheless, organic sulfur constitutes most sulfur in soils. Recent reports demonstrate that the mobilization of organic-bound-sulfur as sulfate in terrestrial environments occurs preferentially under high temperatures and thermophilic Firmicutes bacteria play a major role in the process, carrying out dissimilative organic-sulfur oxidation. So far, the determinant metabolic reactions of such activity have not been evaluated. Here, in silico analysis was performed on the genomes of sulfate-producing thermophilic genera and mesophilic low-sulfate producers, revealing that highest sulfate production is related to the simultaneous presence of metabolic pathways leading to sulfite synthesis, similar to the ones found in mammalian cells. Those pathways include reverse transsulfuration reactions (tightly associated with methionine cycling), and the presence of aspartate aminotransferases (ATs) with the potential of 3-sulfinoalanine AT and cysteine AT activity, which ultimately leads to sulfite production. Sulfite is oxidized to sulfate by sulfite oxidase, this enzyme is determinant in sulfate synthesis, and it is absent in many mesophiles. [ABSTRACT FROM AUTHOR]

Structures, energetics and infrared (IR) spectra of the SeO42−.nH2O, CrO42−.nH2O and SO42−.nH2O clusters at ωB97X-D/aug-cc-pvtz level of theory are studied. It is observed that both the microhydrated SeO42−and CrO42−clusters are stabilised by double-hydrogen bonding (DHB), single-hydrogen bonding (SHB) and H-bonded cyclic water ring arrangements like the microhydrated SO42−cluster. It is also observed that the conformations having cyclic water network are found to be more stable in contrast to the other conformers having SHB or DHB arrangements. The calculated solute–solvent interaction energy for a particular structure is found to be nearly same (within 2%–6%) for all the hydrated clusters. The structure having at least one cyclic water ring is characterised by a peak in the range of 3450–3480 cm−1in the IR spectra for all the systems. A single sharp peak at ∼3520 cm−1is observed for the structure with six double-hydrogen arrangements. We do observe a near indistinguishable IR spectral pattern (within 1%) in the O–H stretching region for a particular structure in all the systems. It may be attributed to the same oxidation state of the central atom, identical geometry of the hydrated cluster and nearly same solute–solvent interaction energy. [ABSTRACT FROM AUTHOR]

The present work investigates the electrodeposition of Zn and Zn–Co alloys from a sulphate bath on stainless steel substrate using cyclic voltammetry and transient current methods. Corrosion behaviour of Zn and Zn–Co alloy coatings in 3.5 wt-% NaCl solution was studied using potentiodynamic polarisation, open circuit potential, Tafel plots and electrochemical impedance spectroscopy. The results showed that the corrosion resistance of the deposits was highly influenced by the composition and morphology of the coatings. This resistance increases with the increase of the [Co2+]/[Zn2+] ratio in the solution. [ABSTRACT FROM AUTHOR]

In this paper, the sulphate ion migration process of concrete under the coupling action of alternating loading and sulphate corrosion is investigated. Chemical analysis method is used to investigate the sulphate ion migration process of interior concrete. The results show that compared with the static loading and the no loading, the alternating loading can accelerate the sulphate ion migration in the cement concrete which is subjected to sulphate attack. The sulphate ion concentration on the surface of concrete under alternating loading is higher than static loading. With the increase of depth, the difference between the alternating loading and the static loading becomes smaller gradually. When the stress level is greater than 40%, the sulphate ion diffusion is improved obviously. It is also found that on the condition of that water-cement ratio met requirements of the concrete workability, low water-cement ratio will improve the durability of concrete under the coupling action of alternating loading and sulphate corrosion. [ABSTRACT FROM AUTHOR]

The characteristics of early diagenetic processes, which influenced the composition of the organic matter of coals from the Krepoljin coal basin, Serbia, Miocene age was assessed by statistical correlation analysis and multivariate principal component analysis. The complexity of processes in a coal-forming sedimentary environment has been paid special attention to obtain the most possible reliable interpretation of these early diagenetic processes and, therefore, this investigation was performed by applying principal component analysis. The principal components, which are defining the coals and promoting individual early diagenetic processes, were the precursor materials and environmental factor, respectively, represented by higher plants, algae, and molds—expressed by the relative contents of the Cs29-, Cs28-, Cs27-steranes, respectively, and the content of organic sulphur—Sorg, average content 166 ± 101 μmole/g. The main and highly interrelated effects of the higher plant material were as follows: (i) increase of the sulphur content of coal organic matter, (ii) promoter of sulphate reducing conditions, and (iii) establishment of the H/C- and N/C-ratios of organic matter. Pyrite formed by the participation of Sorg. [ABSTRACT FROM PUBLISHER]

To study the influence of urban heat island effect on sulphate attack on concrete, three environments are designed to simulate both sulphate attack underground and crystallisation attack on the ground surface. Experiments last for 1 year and then all specimens are taken out to conduct macro-observations and micro-observations. Results indicate the following: after attack, the micro-structural change of concrete is in accord with the macro-mechanical behaviour; under the influence of urban heat island effect, the visual degradation mainly induced by ettringite is much more serious and the crystallisation attack mainly induced by thenardite crystal is extended to greater range, and therefore the compressive strength is decreased more obviously. The degradation is particularly prominent for C20 concrete, this should be paid more attention, because in China, C20 concrete was often adopted by relatively early building foundation and underground pipeline. This research will provide good basis for further putting forward repair techniques to the attacked concrete material. [ABSTRACT FROM AUTHOR]

Synthesis of modified cellulose (Cell-GTA) containing quaternary amine functionality was performed. The adsorbent was used to adsorb phosphate and sulphate anions at different experimental conditions using batch method. Kinetic and thermodynamic properties as well as the mechanism of interaction between studied anions and adsorbent were discussed. The adsorption behavior of the obtained samples showed high adsorption capacity as well as fast uptake toward studied anions in their solutions. The maximum adsorption capacities ofandon Cell-GTA were found to be 1.88 and 3.68 mmol/g, respectively. Regeneration of the loaded adsorbents toward the successive reuse was also investigated. [ABSTRACT FROM PUBLISHER]

The β-glucans (β-G) are polysaccharides produced by various organisms, and sulfation of β-G renders them more soluble. With the objective to assess the effects of sulfated and non-sulfated β-G extracted fromAgaricus brasiliensisin MCF-7 cells, assays were used to evaluate cytotoxicity, genotoxicity, cell proliferation and mRNA expression. The sulfated and non-sulfated β-G showed dose-dependent cytotoxicity at concentrations of 5 and 10 μg/mL, by the MTT assay. However, only cytotoxicity was observed after 24 h by the Red Neutral test for sulfated β-G, with no genotoxicity for either β-G in comet assay. Proliferation was decreased only at 72 h at a concentration of 100 μg/mL of sulfated β-G. Treatment with 5 μg/mL of sulfated β-G for 6 h reduced the expression of pro-apoptotic genes and stress signaling genes, cell cycle arrest, damage and cell migration. The 5 μg/mL of non-sulfated β-G for 6 h reduced the expression of the stress response gene and signaling damage. These results indicate that the cytotoxicity in the MTT is not cell death, and that, in general, sulfated β-G have greater cytotoxicity compared to non-sulfated β-G. [ABSTRACT FROM AUTHOR]

Formation of mineral scales of carbonate and sulphate poses significant problems in cooling water systems. For the control of calcium carbonate and calcium sulphate scales, a novel environmentally friendly type of scale inhibitor ALn was synthesized. The antiscale property of the ALn copolymer towards CaCO3and CaSO4in the artificial cooling water was studied through static scale inhibition tests, The observation shows that both CaCO3and CaSO4inhibition increase with increasing the degree of polymerization of ALn from 5 to 15, andthe dosage of ALn plays an important role on CaCO3and CaSO4inhibition. The effect on formation of CaCO3and CaSO4was investigated with combination of scanning electronic microscopy, transmission electron microscopy, and X-ray powder diffraction analysis, respectively. Inhibition mechanism is proposed that the interactions between calcium and polyethylene glycol are the fundamental impetus to restrain the formation of the scale in cooling water systems. [ABSTRACT FROM AUTHOR]