Structural characterization, exploiting X-ray scattering differences at elemental absorption edges, is developed to quantitatively determine crystallographic site-specific metal disorder. We apply this technique to the problem of Zn-Cu chemical disorder in ZnCu(3)(OH)(6)Cl(2). This geometrically frustrated kagomé antiferromagnet is one of the best candidates for a spin-liquid ground state, but ...

This report represents the completion of a two-year Laboratory-Directed Research and Development (LDRD) program to investigate miniaturized systems for chemical detection and analysis. The future of advanced chemical detection and analysis is in miniature devices that are able to characterize increasingly complex samples, a "laboratory on a chip". In this concept, chemical operations used to an...

Atomic force microscopy-based infrared spectroscopy (AFM-IR) is a rapidly emerging technique that provides chemical analysis and compositional mapping with spatial resolution far below conventional optical diffraction limits. AFM-IR works by using the tip of an AFM probe to locally detect thermal expansion in a sample resulting from absorption of infrared radiation. AFM-IR thus can provide the ...

This paper is dedicated to study the thin polycrystalline films of semiconductor chalcogenide materials (CdS, CdSe, and PbS) obtained by ammonia-free chemical bath deposition. The obtained material is of polycrystalline nature with crystallite of a size that, from a general point of view, should not result in any noticeable quantum confinement. Nevertheless, we were able to observe blueshift of...

Studies aimed at the development of analytical methods based on electrothermal atomic absorption spectrometry for the determination of antimony, selenium and arsenic in gasoline and kerosene were performed. The goal was to develop sensitive methods that allow a simple calibration procedure to be used through direct correlation between analyte signals measured in the sample and signals from aque...

Electrothermal atomic absorption spectrometry (ETAAS) is considered the most common and advanced technique to determine trace lithium in biological fluids. However, chloride existing in samples has been reported to create serious interferences. Nitric acid was verified as a chemical modifier to eliminate the interference of chloride in determining trace lithium in urine samples and the possible...

Background: Developing effective methods for the synthesis of bio-compatible and non-toxic nanoparticles is the main goal of nanotechnology. In the most chemical methods, a chemical reducing agent is used to reduce metal ions. But, in chemical methods, the stability of nanoparticles is controversial and synthesis in large sizes is much more difficult. Moreover, there is an incr...

dispersive liquid-liquid microextraction technique based on solidification of a floating organic drop (dllme-sfo) combined with flame atomic absorption spectrometry was developed for determination of thallium in water sample. an appropriate mixture of acetone and 1-undecanol was rapidly injected into an aqueous sample containing tlcl4- which forms an ion pair with brilliant green reagent and as...

PDT is a procedure using light (often low-power laser light or LED) absorption by the external chemical agents (or photosensitizers) causing photo-chemical reactions in the treated tissues. Many photosensitizers have been developed to match the absorption peaks of light wavelengths ranging from ultraviolet (300-390 nm), visible (400-700 nm) to near-IR (700-950 nm) for applications such as in de...

Hydrogen-bond acidic polymers are important high affinity materials sensitive to organophosphates in the chemical warfare agent sensor detection process. Interactions between the sensor sensitive materials and chemical warfare agent simulants were studied by inverse gas chromatography. Hydrogen bonded acidic polymers, i.e., BSP3, were prepared for micro-packed columns to examine the interaction...