Electrohydrodynamic Kelvin-Helmholtz instability for a velocity stratified fluid

AbstractThe electrohydrodynamic stability of a conducting incompressible stratified fluid topping a dielectric fluid layer is studied. The stability of the system is discussed theoretically and numerically. It is found that the normal electric field has a destabilising effect while the increase of the thickness of the layer has a stabilising influence. The special case of the Rayleigh-Taylor instability is also examined

Fabrication of an Inorganic Nano-Zirconium Tungstovanadate Ion Exchange to Be Utilized for Heavy Metal Decontamination

An innovative heteropolyacid salt of ion exchanger, nano-zirconium tungstovanadate has been synthesized under varying conditions using sol–gel technique. The different synthesized ion exchange materials were compared based on both their ion exchange capacity (IEC) and their efficiency in separating lead ions from aqueous streams by conducting batch experiments with a batch factor of 50ml/g. Nano- zirconium tungstovanadate prepared from the reaction of 0.2 M zirconiumoxychloride, 0.2M ammonium metavanadate and 0.1 M sodium tungstate in presence of 0.01 M HCl at room temperature was record the highest IEC value that equal to 1.5 mequiv/g. Structural characterization of this most proper ion exchanger was performed with powder X-ray diffraction (XRD), thermogravimetry (TGA), scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS) and with inductively coupled plasma optical emission spectrometry (ICP-OES). The X-ray spectrum of the prepared material suggested that of Zr (IV) tungstovanadate is crystalline in nature with average crystallite size between19 and 37 nm. The SEM result confirmed that the ion exchanger was produced in nano-scale with average particle diameter equal to 28 nm. Good thermal and chemical stabilities have also been observed for the prepared nano-zirconium tungstovanadate. On the basis of these results, the prepared nano-zirconium tungstovanadate is a promising cation exchanger for lead ion decontamination from the polluted water in view of the factthat lead ion removal rate was recorded up to 99.24 % within 3hours.Keywords: nano- zirconium tungstovanadate; sol-gel technique; equilibrium isotherm; Lead ion separation

Fabrication of an Inorganic Nano-Zirconium Tungstovanadate Ion Exchange to be Utilized for Heavy Metal Decontamination

An innovative heteropoly acid salt of ion exchanger, nano-zirconium tungstovanadate has been synthesized under varying conditions using sol–gel technique. The different synthesized ion exchange materials were compared based on both their ion exchange capacity (IEC) and their efficiency in separating lead ions from aqueous streams by conducting batch experiments with a batch factor of 50ml/g. Nano- zirconium tungstovanadate prepared from the reaction of 0.2 M zirconium oxychloride, 0.2M ammonium metavanadate and 0.1 M sodium tungstate in presence of 0.01 M HCl at room temperature was record the highest IEC value that equal to 1.5 mequiv/g. Structural characterization of this most proper ion exchanger was performed with powder X-ray diffraction (XRD), thermogravimetry (TGA), scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS) and with inductively coupled plasma optical emission spectrometry (ICP-OES). The X-ray spectrum of the prepared material suggested that of Zr (IV) tungstovanadate is crystalline in nature with average crystallite size between 19 and 37 nm. The SEM result confirmed that the ion exchanger was produced in nanoscale with average particle diameter equal to 28 nm. Good thermal and chemical stabilities have also been observed for the prepared nano-zirconium tungstovanadate. On the basis of these results, the prepared nano-zirconium tungstovanadate is a promising cation exchanger for lead ion decontamination from the polluted water in view of the fact that lead ion removal rate was recorded up to 99.24 % within 3hours

Electro-osmotic flow of couple stress fluids in a microchannel propagated by peristalsis

A mathematical model is developed for electro-osmotic peristaltic pumping of a non-Newtonian liquid in a deformable micro-channel. Stokes’ couple stress fluid model is deployed to represent realistic working liquids. The Poisson-Boltzmann equation for electric potential distribution is implemented owing to the presence of an electrical double layer (EDL) in the micro-channel. Using long wavelength, lubrication theory and Debye-Huckel approximations, the linearized transformed dimensionless boundary value problem is solved analytically. The influence of electro-osmotic parameter (inversely proportional to Debye length), maximum electro-osmotic velocity (a function of external applied electrical field) and couple stress parameter on axial velocity, volumetric flow rate, pressure gradient, local wall shear stress and stream function distributions is evaluated in detail with the aid of graphs. The Newtonian fluid case is retrieved as a special case with vanishing couple stress effects. With increasing couple stress parameter there is a significant elevation in axial pressure gradient whereas the core axial velocity is reduced. An increase in electro-osmotic parameter induces both flow acceleration in the core region (around the channel centreline) and also enhances axial pressure gradient substantially. The study is relevant to simulation of novel smart bio-inspired space pumps, chromatography and medical microscale devices

Anemia prevalence in women of reproductive age in low- and middle-income countries between 2000 and 2018

Anemia is a globally widespread condition in women and is associated with reduced economic productivity and increased mortality worldwide. Here we map annual 2000–2018 geospatial estimates of anemia prevalence in women of reproductive age (15–49 years) across 82 low- and middle-income countries (LMICs), stratify anemia by severity and aggregate results to policy-relevant administrative and national levels. Additionally, we provide subnational disparity analyses to provide a comprehensive overview of anemia prevalence inequalities within these countries and predict progress toward the World Health Organization’s Global Nutrition Target (WHO GNT) to reduce anemia by half by 2030. Our results demonstrate widespread moderate improvements in overall anemia prevalence but identify only three LMICs with a high probability of achieving the WHO GNT by 2030 at a national scale, and no LMIC is expected to achieve the target in all their subnational administrative units. Our maps show where large within-country disparities occur, as well as areas likely to fall short of the WHO GNT, offering precision public health tools so that adequate resource allocation and subsequent interventions can be targeted to the most vulnerable populations.Peer reviewe

Systematic Review of Potential Health Risks Posed by Pharmaceutical, Occupational and Consumer Exposures to Metallic and Nanoscale Aluminum, Aluminum Oxides, Aluminum Hydroxide and Its Soluble Salts

Aluminum (Al) is a ubiquitous substance encountered both naturally (as the third most abundant element) and intentionally (used in water, foods, pharmaceuticals, and vaccines); it is also present in ambient and occupational airborne particulates. Existing data underscore the importance of Al physical and chemical forms in relation to its uptake, accumulation, and systemic bioavailability. The present review represents a systematic examination of the peer-reviewed literature on the adverse health effects of Al materials published since a previous critical evaluation compiled by Krewski et al. (2007). Challenges encountered in carrying out the present review reflected the experimental use of different physical and chemical Al forms, different routes of administration, and different target organs in relation to the magnitude, frequency, and duration of exposure. Wide variations in diet can result in Al intakes that are often higher than the World Health Organization provisional tolerable weekly intake (PTWI), which is based on studies with Al citrate. Comparing daily dietary Al exposures on the basis of “total Al”assumes that gastrointestinal bioavailability for all dietary Al forms is equivalent to that for Al citrate, an approach that requires validation. Current occupational exposure limits (OELs) for identical Al substances vary as much as 15-fold. The toxicity of different Al forms depends in large measure on their physical behavior and relative solubility in water. The toxicity of soluble Al forms depends upon the delivered dose of Al+ 3 to target tissues. Trivalent Al reacts with water to produce bidentate superoxide coordination spheres [Al(O2)(H2O4)+ 2 and Al(H2O)6 + 3] that after complexation with O2•−, generate Al superoxides [Al(O2•)](H2O5)]+ 2. Semireduced AlO2• radicals deplete mitochondrial Fe and promote generation of H2O2, O2 • − and OH•. Thus, it is the Al+ 3-induced formation of oxygen radicals that accounts for the oxidative damage that leads to intrinsic apoptosis. In contrast, the toxicity of the insoluble Al oxides depends primarily on their behavior as particulates. Aluminum has been held responsible for human morbidity and mortality, but there is no consistent and convincing evidence to associate the Al found in food and drinking water at the doses and chemical forms presently consumed by people living in North America and Western Europe with increased risk for Alzheimer\u27s disease (AD). Neither is there clear evidence to show use of Al-containing underarm antiperspirants or cosmetics increases the risk of AD or breast cancer. Metallic Al, its oxides, and common Al salts have not been shown to be either genotoxic or carcinogenic. Aluminum exposures during neonatal and pediatric parenteral nutrition (PN) can impair bone mineralization and delay neurological development. Adverse effects to vaccines with Al adjuvants have occurred; however, recent controlled trials found that the immunologic response to certain vaccines with Al adjuvants was no greater, and in some cases less than, that after identical vaccination without Al adjuvants. The scientific literature on the adverse health effects of Al is extensive. Health risk assessments for Al must take into account individual co-factors (e.g., age, renal function, diet, gastric pH). Conclusions from the current review point to the need for refinement of the PTWI, reduction of Al contamination in PN solutions, justification for routine addition of Al to vaccines, and harmonization of OELs for Al substances

Search for single production of scalar leptoquarks in proton-proton collisions at root s=8 TeV

Correction DOI:10.1103/PhysRevD.95.039906Peer reviewe