Antimony-bearing schwertmannite transformation to goethite: A driver of antimony mobilization in acid mine drainage.

Antimony(V) mobility in acid mine drainage (AMD) is often controlled by sorption and coprecipitation with schwertmannite - a poorly-ordered Fe(III) oxyhydroxysulfate mineral. However, due to its metastable nature, schwertmannite transforms over time to more thermodynamically stable Fe(III) phases, such as goethite. This study examines how transformation of Sb(V)-bearing schwertmannite to goethite impacts Sb(V) mobility, while also assessing the role that Sb(V) may play in stabilizing schwertmannite against such transformation.

Antimony(V) sorption and coprecipitation with ferrihydrite: An examination of retention mechanisms and the selectivity of commonly-applied extraction procedures.

We investigated the mechanisms that control Sb(V) sorption and coprecipitation with ferrihydrite across a range of Sb(V) loadings, and examined the associated effects on Sb(V) extractability during the commonly-applied 1 M HCl extraction scheme and the BCR and Wenzel sequential extraction schemes. EXAFS spectroscopy reveals that Sb(V) sorption and coprecipitation mainly involved Sb(V) incorporation into the ferrihydrite structure via edge sharing and double-corner sharing between SbO and FeO octahedra. Large amounts of these linkages partially stabilized ferrihydrite against extraction with 1 M HCl.

Antimony sorption to schwertmannite in acid sulfate environments.

Schwertmannite is a poorly-crystalline Fe(III) oxyhydroxysulfate mineral that may control Sb(V) mobility in acid sulfate environments, including acid mine drainage and acid sulfate soils. However, the mechanisms that govern uptake of aqueous Sb(V) by schwertmannite in such environments are poorly understood. To address this issue, we examined Sb(V) sorption to schwertmannite across a range of environmentally-relevant Sb(V) loadings at pH 3 in sulfate-rich solutions.

Antimony(V) Incorporation into Schwertmannite: Critical Insights on Antimony Retention in Acidic Environments.

This study examines incorporation of Sb(V) into schwertmannite─an Fe(III) oxyhydroxysulfate mineral that can be an important Sb host phase in acidic environments. Schwertmannite was synthesized from solutions containing a range of Sb(V)/Fe(III) ratios, and the resulting solids were investigated using geochemical analysis, powder X-ray diffraction (XRD), dissolution kinetic experiments, and extended X-ray absorption fine structure (EXAFS) spectroscopy. Shell-fitting and wavelet transform analyses of Sb K-edge EXAFS data, together with congruent Sb and Fe release during schwertmannite dissolution, indicate that schwertmannite incorporates Sb(V) via heterovalent substitution for Fe(III).

Health risk assessment and source apportionment of potentially toxic metal(loid)s in windowsill dust of a rapidly growing urban settlement, Iran.

Rapid industrialization and urbanization have resulted in environmental pollution and unsustainable development of cities. The concentration of 12 potentially toxic metal(loid)s in windowsill dust samples (n = 50) were investigated from different functional areas of Qom city with the highest level of urbanization in Iran. Spatial analyses (ArcGIS 10.

Electrospun Polyacrylonitrile/Clinoptilolite Coating for SPME of PAHs from Water Samples.

Electrospun polyacrylonitrile/clinoptilolite (PAN/CP) nanofibers were used to extract polycyclic aromatic hydrocarbons (PAHs) (acenaphthene, acenaphthylene, naphthalene, and phenanthrene) from water samples by solid-phase microextraction (SPME). The target PAHs was detected and quantified by gas chromatography equipped with a flame ionization detector. The PAN/CP fibrous coating with uniform morphology and without beads was electrospun after optimizing the electrospinning parameters by the Taguchi method.

DiCENet: Dimension-Wise Convolutions for Efficient Networks.

We introduce a novel and generic convolutional unit, DiCE unit, that is built using dimension-wise convolutions and dimension-wise fusion. The dimension-wise convolutions apply light-weight convolutional filtering across each dimension of the input tensor while dimension-wise fusion efficiently combines these dimension-wise representations; allowing the DiCE unit to efficiently encode spatial and channel-wise information contained in the input tensor. The DiCE unit is simple and can be seamlessly integrated with any architecture to improve its efficiency and performance.

Determination of polycyclic aromatic hydrocarbons in non-alcoholic beer by mechanical stir bar sorptive extraction-gas chromatography.

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Electronic Supplementary Material: The online version of this article (10.1007/s13197-020-04411-8) contains supplementary material, which is available to authorized users.

An improvement of electrospun membrane reusability via titanium dioxide nanoparticles and silane compounds for the electromembrane extraction.

A polyacrylonitrile (PAN)/polydimethylsiloxane (PDMS) flat membrane was fabricated by electrospinning technique and modified using titanium dioxide (TiO) nanoparticles and low-energy materials, dimethyldichlorosilane (MeSiCl)/methyltrichlorosilane (MeSiCl), to obtain a hydrophobic surface. The new membrane was utilized for the electromembrane extraction (EME) of model molecules including dibutyl phthalate (DBP) and bis [2-ethylhexyl] phthalate (DEHP). The parameters affecting proposed EME were optimized by the response surface methodology (RSM) based on the central composite design (CCD).

Assessing the effect of community health nursing care management at home on war-worn soldiers' physical problems suffering from spinal cord complications (urinary infection, bedsore).

Background: Veterans are among the highly-susceptible and highly-esteemed groups of the society. there is no correct, principled, and comprehensive programming with respect to home-nursing care for them.

Methods: In this quasi-experimental study, 26 veterans with spinal cord complications, with a 70-percent damage who were resident of Najaf Abad, Iran were concluded.

Evaluation of quality of working life and its association with job performance of the nurses.

Background: Nurses often complain about overwork and underpay. It seems that the association between "quality of working life" (QWL) and the degree of nurses' involvement in their carrier is the critical factor in achieving a higher level of quality of care. This study aimed to assess the quality of working life and its association with "job performance" of the nurses in educational hospitals affiliated to Isfahan University of Medical Sciences in 2007.

The study of optimal nursing position in health care delivery system in Iran.

Background: In the recent decade, due to the overwhelming importance of health and prevention of diseases, nurses, the greatest part of the health care system, are acting in any position of the health care delivery system; because nursing have a key role in promotion of health and health care everywhere. The objective of this research was to study the desired positions of nursing in the health care delivery system in Iran.

Methods: This was a triangulation study done on three steps during 2005-2007.