The correlation between sub-band gap absorption and the chemical states and electronic and atomic structures of S-hyperdoped Si have been extensively studied, using synchrotron-based x-ray photoelectron spectroscopy (XPS), x-ray absorption near-edge spectroscopy (XANES), extended x-ray absorption fine structure (EXAFS), valence-band photoemission spectroscopy (VB-PES) and first-principles calcu...

Reduced graphene oxides with varying degrees of reduction have been produced by hydrazine reduction of graphene oxide. The linear and nonlinear optical properties of both graphene oxide as well as the reduced graphene oxides have been measured by single beam Z-scan measurement in the picosecond region. The results reveal both saturable absorption and two-photon absorption, strongly dependent on...

The role of diet or its components in the absorption, distribution and toxicity of cadmium (Cd) has received attention in recent times. Experimental evidence in literature strongly suggests that the absorption of Cd is dependent on factors such as age, pH, diet and intestinal metallothionein (MT) production. The chemical forms of Cd such as Cd-MT in foods or inorganic Cd administered directly i...

cadmium sulfide nanoparticles were grown using wet chemical method by dissolving the reactants ofcadmium acetate and sodium sulfide in the presence of thioglycerol (tg) as capping agent in ethanolsolvent. different nanoparticle sizes and size distribution were obtained through varying the molaritiesof thioglycerol. at higher tg concentration, synthesis provides a nearly monodisperse nanoparticl...

Although the definition and measurement techniques for atmospheric “black carbon” (“BC”) or “elemental carbon” (“EC”) have long been subjects of scientific controversy, the recent discovery of light-absorbing carbon that is not black (“brown carbon, Cbrown”) makes it imperative to reassess and redefine the components that make up lightabsorbing carbonaceous matter (LAC) in the atmosphere. Evide...

The toxicity and corrosion potential of hydrogen sulfide in raw biogas underlines the need for biogas purification. Several techniques available for removal of hydrogen sulfide from biogas are out of the reach for common end users due to lack of knowledge, higher running costs, and insufficient operational skills. The present experimental study aims to propagate hydrogen sulfide removal techniq...

ZnO nanocrystals were successfully fabricated by wet-chemical method. Optical properties of excitons confined in ZnO nanocrystals were studied by measuring both optical absorption and photoluminescence spectra. Absorption due to free excitons was clearly observed whereas strong PL lines were recorded in the UV region at around the exciton absorption energy. Red-shift of optical features with in...

The two-photon-induced singlet fission was observed in rubrene single crystal and studied by use of femtosecond pump-probe spectroscopy. The location of two-photon excited states was obtained from the nondegenerate two-photon absorption (TPA) spectrum. Time evolution of the two-photon-induced transient absorption spectra reveals the direct singlet fission from the two-photon excited states. The...

This article outlines a method to interpret the extragalactic background light in terms of the large-scale, average properties of galaxies , including the comoving densities of stars and interstellar gas, metals, and dust. These quantities are related by a series of coupled conservation-type equations analogous to the equations of galactic chemical evolution. This approach enables us to combine...

Two sets of hydrogenated microcrystalline silicon thin-film samples were prepared by Plasma Enhanced Chemical Vapor Deposition (PECVD) technique at different deposition conditions of excited power and pressure. The correlation between the crystalline volume fraction for the samples determined from Raman spectra and the excited power, pressure, absorption coefficient, refractive index and optica...