Oxidation of Dimethyl Sulfide in Air Using Electron-Beam Irradiation,and Enhancement of its Oxidation Via an MnO<Subscript>2</Subscript> Catalyst

The decomposition of dimethyl sulfide (DMS) at initial concentrations of 4.5–18.0 ppmv in air was studied under electron-beam (EB) irradiation. Doses to decompose 90% of input DMS were 2.5 kGy for 4.5 ppmv, 3.4 kGy for 10.6 ppmv, and 3.9 kGy for 18.0 ppmv. HCOOH, (CH₃)₂SO, and trace CH₃OH and (CH₃)₂SO₂ were produced as irradiation products in addition to CO₂ and CO. Application of an O₃ decomposition catalyst to an irradiated sample gas led to an enhancement in the oxidation of DMS and its products into CO₂ and the decomposition of O₃. For 10.6 ppmv DMS/air, the mineralization ratio increased from 41% via only EB irradiation to 100% via the combination treatment at 6.3 kGy. The yield of CO₂ to CO_x increased from 5.3 to 87.6% by combination with catalytic oxidation. This combination treatment enables the irradiation energy used to deodorize gas streams containing DMS to be reduced.     

Diffraction of love waves by two staggered perfectly weak half-planes

Summary Love wave travelling in a layer of uniform thickness overlying a half-space is assumed to be incident on two parallel but staggered perfectly weak half-planes lying in the upper layer. The diffracted field is calculated using the modified Wiener-Hopf technique and contour integration method. The diffracted waves satisfy the dispersion relations appropriate to different regions formed by the perfectly weak half-planes. To the memory of M. H. Kazi     

TiO2 as a Reusable Catalyst for the One‐Pot Synthesis of 3,4‐Dihydropyrimidin‐2(1H)‐ones under Solvent‐Free Conditions

An efficient solvent‐free method for the synthesis of various 3,4‐dihydropyrimidin‐2(1H)‐ones using TiO₂ as a recyclable heterogeneous catalyst is described. Compared to known methods, satisfactory results are obtained with excellent yields, short reaction times, and simplicity in the experimental procedure.     

A note on a symmetry analysis and exact solutions of a nonlinear fin equation

A similarity analysis of a nonlinear fin equation has been carried out by M. Pakdemirli and A.Z. Sahin [Similarity analysis of a nonlinear fin equation, Appl. Math. Lett. (2005) (in press)]. Here, we consider a further group theoretic analysis that leads to an alternative set of exact solutions or reduced equations with an emphasis on travelling wave solutions, steady state type solutions and solutions not appearing elsewhere.     

Magnetic CuO nanoparticles supported on graphene oxide as an efficient catalyst for A3-coupling synthesis of propargylamines

Magnetically separable CuO nanoparticles supported on graphene oxide (Fe₃O₄ NPs/GO-CuO NPs) is synthesized and characterized for the preparation of propargylamines in EtOH, at 90℃. Fe₃O₄ NPs/GO-CuO NPs is found to be an efficient catalyst for the A³-coupling of aldehydes, amines, and alkynes through C-H activation. Both aromatic and aliphatic aldehydes and alkynes are combined with secondary amines to provide a wide range of propargylamines in moderate to excellent yields.     

Exact solutions of some general nonlinear wave equations in elasticity

A similarity analysis of a nonlinear wave equation in elasticity is studied; in particular, one with anharmonic corrections. The symmetry transformation give rise to exact solutions via the method of invariants. In some cases, graphical figure of the solutions are presented. Furthermore, we consider some cases wherein the velocities of the longitudinal and transversal plane waves are variable. Finally, a brief discussion on how a symmetry analysis on a perturbation of the elasticity equation can be pursued.     

Tackling HIV through robust diagnostics in the developing world: current status and future opportunities

Over the last thirty years, the world has seen HIV circulate the globe, affecting 33 million people to date and killing 2 million people a year. The disease has affected developed and developing countries alike, and in the U.S., remains one of the top ten leading causes of death. Many regions of the world are highly impacted by this disease, including sub-Saharan Africa, South and South-East Asia, and Eastern Europe. Fortunately, multilateral, global efforts, along with successful developments in diagnostic tools and anti-retroviral drugs (ARVs) have successfully curbed the spread of HIV over the last ten years. In spite of this fact, access to HIV treatment and preventive healthcare is varying and limited in developing countries. A lack of healthcare infrastructure, financial support, and healthcare workers are some logistical factors that are responsible. HIV stigmatization, discrimination, and inadequate education pose additional social challenges that are hindering countries from advancing in HIV prevention. This review focuses on current technological tools that are used for HIV diagnosis and ongoing research that is aimed at addressing the conditions in low-resource settings. Recent developments in microfluidic applications and mobile health technologies are promising approaches to building a compact, portable, and robust device that can provide information-rich, real-time diagnoses. We also discuss the role that governments, healthcare workers, and even researchers can play in order to increase the acceptance of newly introduced devices and treatments in rural communities.     

Extractives of Milletia ovalifolia

Isolation of lanceolatin B, the flavanones 1 and 2, the flavones 3 and 4 and the dibenzoylmethane 5 from M. ovalifolia is reported. The structures were assigned from spectral data and confirmed by synthesis.