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In this research, Ag+ and Al3+ doped CuInS2 (CIS) nanoparticles were synthesized by a low-cost and non-vacuum hydrothermal method. The CuInS2 nanoparticles were synthesized by the stoichiometric ratio of (1Cu: 1In: 2S) using the hydrothermal method at 180℃ and for 16, 18 and 20 h. Afterward, Ag+ and Al3+ ions were doped with non-stoichiometric composition of (Cu1-xAgx)InS2, Cu(In1-xAlx)S2 (x = 0.1, 0.2, and 0.3), and (Cu1-xAgx)(In1-xAlx)S2 (x = 0.1). The phase evolution, microstructural, and optical properties have also been studied by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), UV–Vis spectroscopy techniques. The XRD results showed that the sample was prepared by the hydrothermal route at 180° C for 20 h was single-phase and no impurity phase was detected. However, some minor impurity phases (CuS and Cu9S5) were detected in the samples were synthesized at 180° C in 16 h and 18 h. The results show that the crystallite size of the synthesized nanoparticles of CIS at 16, 18, and 20 h are 26, 29, and 32 nm, respectively. The lattice parameters for the sample synthesized in 20 h were calculated to be 5.52 A (a) and 11.11 A (c). The FE-SEM micrographs showed that the pure CIS nanoparticles have flower-shaped morphology and the type and concentration of used dopants affect the morphology of the nanoparticles. The bandgap of single-phase CIS synthesized nanoparticles was 1.5 eV. However, the bandgap of (Cu0.9Ag0.1)InS2 and Cu(In0.9Al0.1)S2 was 1.4 eV and 1.70, respectively. The bandgap of (Cu0.9Ag0.1) (In0.9Al0.1)S2 was 2 eV.

A number of batch polymerizations were performed to study the effect of pristine nanoparticle loading on the properties of PMMA/silica nanocomposites prepared via RAFT polymerization. In order to improve the dispersion of silica nanoparticles in PMMA matrix, the silanol groups of the silica are functionalized with methyl methacrylate groups and modified nanoparticles were used to synthesize PMMA/modified silica nanocomposites via RAFT polymerization. Prepared samples were characterized by thermogravimetric analysis (TGA), dynamic light scattering (DLS), dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC) and gel permeation chromatography (GPC). According to results, introduction of modified nanoparticles results in better thermal and mechanical properties than those of pristine nanoparticles. Also, surface modification and increasing silica nanoparticles result in variation of thermal degradation behavior of nanocomposites. The best improvement of mechanical and thermophysical properties is achieved for nanocomposites containing 7 wt. % silica nanoparticles.

Many researchers have addressed the problem of uniquely identifying updates in a distributed database system in the literature. Primitive identification schemes that generate globally unique update IDs have also been suggested. These IDs are usually used as priority among updates as well. When used as such, these schemes do not distribute priority evenly across the nodes. This paper presents a numbering scheme that generates unique update IDs and, if used as a priority scheme, is fair.