Synthesis, Characterization and DNA-binding Interactions of Inorganic Nanoparticles

Nanoparticles, with their unique mechanical, electronic, optical and magnetic properties due to small size at nanoscales attracted many scientists from different disciplines of science. In recent years, nano-based materials have found potential applications in electronics, materials as fillers, cosmetics, drug delivery systems, medicine, and so on. Metal based nanoparticles especially nanoparticles of gold and quantum dots have been considered a lot for their potential applications in biomedical area. Of course, with the rise of nanotechnology, has increased the concern over the risks of nanoparticles. The object of this PhD thesis is the study of synthesis, characterization, stability, DNA binding interactions and damage effects to living cells of differently capped nanoparticles of gold and cadmium sulphide that are of current interest in bio-applications

Experimental investigation of thermal performance of an evacuated U-Tube solar collector with ZnO/Etylene glycol-pure water nanofluids

In this paper, the efficiency of an evacuated U-tube solar collector (EUSC) with ZnO/Etylene Glycol-Pure Water (ZnO/EG-PW) as a working fluid was experimentally investigated. 50\%-50\% EG-PW was used as a base fluid. To prepare the nanofluids ZnO nanoparticles were added to the EG-PW base fluid at different volume concentrations (1.0\%, 2.0\%, 3.0\% and 4.0\%). The maximum collector efficiency was obtained at equal working fluid inlet temperature and ambient temperature in all experiments. Moreover, the highest collector efficiency was determined 62.87\% for 3.0 vol.\% and mass flow rate of 0.045 kg/s that it was 26.42\% higher than EG-PW as a working fluid. Also, this value is 5.2\% and 6.88\% higher than the base fluid for the mass flow rates of 0.03 and 0.02 kg/s, respectively. It was determined also that the thermal conductivity of ZnO/EG-PW nanofluid increases with increasing nanoparticle volume concentration. (C) 2018 Elsevier Ltd. All rights reserved

Anode performance of hydrothermally grown carbon nanostructures and their molybdenum chalcogenides for Li-ion batteries

Three different hydrothermally grown carbonaceous materials and their molybdenum chalcogenides derived from glucose (HTC, HTC-MoO2, HTC-MoS2) were investigated to evaluate their potential as Li-ion battery anodes. All tested materials exhibited good cycling performance at a current density of 100 mA/g and showed high coulombic efficiency, >98%, after the 50th cycle. Reversible charge capacities of HTC, HTC-MoO2, and HTC-MoS2 were 296, 266, and 484 mAh/g, respectively, after 50 successive cycles. This study demonstrated that the HTC-MoS2 showed the highest reversible charge capacity which promises to be a good candidate for an environmentally friendly anode material for Li-ion batteries

Non-covalent interactions of cadmium sulphide and gold nanoparticles with DNA

Mercaptoethanol-capped CdS nanoparticles (CdSnp) and monohydroxy-(1-mercaptoundec-11-yl) tetraethylene-glycol-capped Au nanoparticles (Aunp) were synthesised, characterised and their interactions with DNA were investigated. Aunp are stable in different aqueous solvents, whereas CdSnp do precip- itate in 0.1 M NaCl and form two different cluster types in 0.1 M NaNO3. As regards the CdSnp/DNA interaction, absorbance and fluorescence titrations, ethidium bromide displacement assays and gel elec- trophoresis experiments indicate that a non-covalent interaction between DNA and the CdSnp external surface does take place. The binding constant was evaluated to be equal to (2.2 ± 0.5) 9 105 M-1. On the contrary, concerning Aunp, no direct interaction with DNA could be observed. Possible interaction with serum albumin was also checked, but no effects could be observed for either CdSnp or Aunp. Finally, short- time exposure of cultured cells to nanoparticles revealed the ability of CdSnp to enter the cells and allocate both in cytosol and nucleus, thus promoting cell proliferation at low concentration (p \ 0.005), while longer-time exposure resulted in a significant inhibition of cell growth, accompanied by apoptotic cell death. Aunp neither enter the cells, nor do affect cell proliferation. In conclusion, our data indicate that CdSnp can strongly interact with living cells and nucleic acid while no effects or interactions were observed for Aunp

Efficiency Assessment of an Evacuated U-Tube Solar Collector Using Silver Nanofluid

A water-based silver nanofluid (Ag/PW) was prepared from gelatin-stabilized silver nanoparticles (Ag NPs) of about 15 nm and further used as a working fluid in an evacuated U-tube solar collector (EUSC) to investigate the variation in the collector efficiency. An Ag/PW nanofluid having 0.035 wt\% was prepared and demonstrated a good promise of colloidal stability when dispersed in pure water. Collector efficiency measurements were carried out at outdoor conditions with four different mass flow rate values (0.063, 0.051, 0.033, and 0.02 kg/s). Results showed that Ag/PW have superior heat transfer properties than that of pure water as the base fluid. It was found that the efficiency of the collector was directly proportional to the mass flow rate of the working fluid until an optimum value was attained. Experimental results show that the highest collector efficiency was 72.2\% at 0.051 kg/s mass flow rate, which is 21.3\% higher than that of the pure water