Barium hexaaluminate nanowhiskers synthesized by novel sol-gel process in reverse micellar media

Barium hexaaluminate (BHA) synthesized by coupling of sol-gel process in reverse microemulsions shows a unique nanowhisker morphology and high surface area, which are retained after calcination at 1300 degrees C.     

Synthesis and LPG sensing properties of nano-sized cadmium oxide

This paper reports the synthesis and liquid petroleum gas (LPG) sensing properties of nano-sized cadmium oxide (CdO). The nano-sized CdO powder was successfully synthesized by using a chemical co-precipitation method using cadmium acetate and the ammonium hydroxide, as starting materials and water as a carrier. The resulting nano-sized powder was characterized by X-ray diffraction (XRD) measurements and the transmission electron microscopy (TEM). The LPG sensing properties of the synthesized nano-sized CdO were investigated at different operating temperatures and LPG concentrations. It was found that the calcination temperature and the operating temperature significantly affect the sensitivity of the nano-sized CdO powder to the LPG. The sensitivity is found to be maximum when the calcination temperature was 400 °C. The sensitivity to 75 ppm of LPG is maximum at an operating temperature 450 °C and it was found to be ∼341%. The response and recovery times were found to be nearly 3-5 s and 8-10 s, respectively. The synthesized nano-sized CdO powder is able to detect up to 25 ppm for LPG with reasonable sensitivity at an operating temperature 450 °C and it can be reliably used to monitor the concentration of LPG over the range (25-75 ppm). The experimental results of the LPG sensing studies reveal that the nano-sized CdO powder synthesized by a simple co-precipitation method is a suitable material for the fabrication of the LPG sensor.     

Synthesis,Optical Properties,and Sensing Applications of Gold Nanodots

In this Personal Account, we briefly address our journey in developing photoluminescent nanomaterials for sensing purposes, with a focus on gold nanodots (Au NDs). Their synthetic strategies, optical properties, and sensing applications are emphasized. The Au NDs can be simply prepared from the etching of small‐sized Au nanoparticles (<3 nm in diameter) by thiol compounds such as 11‐mercaptoundecanoic acid under alkaline conditions. This simple approach allows the preparation of various functional Au NDs by choosing different thiol compounds as etching agents. Since the optical properties of Au NDs are highly dependent on the core and shell of each Au ND, the selection of etching reagents is important. Over the years we have developed various sensing systems using Au NDs for the detection of metal ions, anions, and proteins, based on analyte‐induced photoluminescence quenching/enhancement of Au NDs as a result of changes in their oxidation state, shell composition, and structure.     

On decomposition of r-partite graphs into edge-disjoint hamilton circuits

Let K(n;r) denote the complete r-partite graph K(n, n,…, n). It is shown here that for all even n(r ? 1) ? 2, K(n;r) is the union of $\text{n(r ? 1)}\text{2}$ of its Hamilton circuits which are mutually edge-disjoint, and for all odd n(r ? 1) ? 1, K(n;r) is the union of $\text{(n(r ? 1) ? 1)}\text{2}$ of its Hamilton circuits and a 1-factor, all of which are mutually edge-disjoint.     

Low-temperature synthetic method for size-controlled CdSe nanocrystals: utilization of boron selenide

By employing B(2)Se(3) as a selenium source, we demonstrate that at reaction temperatures as low as 60 [degree]C, relatively monodisperse, fluorescent CdSe nanocrystals can be conveniently prepared in various sizes selected from 2 to 13 nm.