Responses of Pt/n-InP Schottky diode to electron irradiation in different temperature conditions

Different radiation and temperature effects on Schottky diodes are technologically important from radiation to sensing applications. We discussed irradiation and temperature dependent electronic properties of Pt/n-InP Schottky contact. Firstly we fabricated Pt/n-InP Schottky diode by magnetron sputtering technique. Then sample was exposed to 12 MeV electron irradiation. We measured I–V characteristics in 20, 160, 300 and 400 K before and after irradiation. Changes in forward currents for 160, 300 and 400 K were not remarkable but irradiation was effective only in 20 K slightly. Reverse currents of Pt/n-InP Schottky diode were increased in 20, 160, 300 and 400 K by irradiation.     

A new synthetic approach for pyrazolo[1,5-a]pyrazine-4(5H)-one derivatives and their antiproliferative effects on lung adenocarcinoma cell line

Molecular Diversity - Starting from the 3,5-dimethyl pyrazole ring and acetophenone derivatives, five different N-propargylated C-3 substituted pyrazoles were obtained. These derivatives were...     

Colloidal nanocomposite hydrogel particles

Quaternary ammonium salt, (3-acrylamidopropyl)-trimethylammonium chloride was used to synthesize nanohydrogel and composite particles such as inorganic–organic hybrid composites and hydrogel nanoparticles with magnetic properties utilizing a water-in-oil microemulsion system. The positively charged cationic monomer was chosen to promote silica hydrolysis and condensation to prepare silica-hydrogel nanocomposite particles with interesting morphologies. It was shown that highly monodisperse, completely charged nanohydrogel can be used to encapsulate ferrite particles. Furthermore, it was also confirmed that cationic nanohydrogel particles with variant morphology can be prepared by employing suitable silica precursor. Morphology, structure, properties, and size of nanocomposite materials were explored utilizing transmission electron microscopy, atomic force microscopy, and vibrating sample magnetometer.     

Graphene oxide embedded P(AAm)/PANI cryogel polymer composites for sensor application against pesticide,nitro compound,and organic dyes

Abstract

Graphene oxide (GO) embedded superporous poly(acrylamide) (P(AAm)) cryogel composites (P(AAm)-GO) were prepared and used as conductive sensor materials. For this goal, the GOs flakes within superporous P(AAm) cryogels were reduced in-situ employing hydriodic acid (HI), hydrazine (N₂H₄), and sodium borohydride (NaBH₄) as reducing agents. Amongst all reduced agents\the highest conductivity was observed for HI reduced P(AAm)-GO (P(AAm)-rGO) with 1.7?×?10^?6±9.7?×?10^?8 S.cm^?1. Then again, this P(AAm)-rGO was used for in-situ synthesis of conductive polymers, poly(aniline) (PANI), and poly(pyrrole) (PPy) by using oxidative polymerization technique. The SEM, FT-IR, TGA and conductivity measurements were done for the characterization of prepared cryogel composites. It was found that the conductivity of P(AAm)-rGO increased 70- and 1400-fold with the presence of PANI and PPy, respectively. Furthermore, potential sensor application of P(AAm)-rGO/conductive polymers were tested against herbicides such as paraquat, glyphosphate (G), and a phenolic compound, 4-nitrophenol (4-NP), and some dyes such as methylene blue (MB), methyl orange (MO). Conductivity of P(AAm)-rGO/PANI decreased 5.3 -fold upon reacting with 10?mL 50?ppm G solution. The sensitivity and effect of G amounts were also tested for P(AAm)-rGO/PANI cryogel composite.     

Determination and evaluation of natural radioactivity and heavy metal levels in the aquatic environment of trans-boundary rivers: Maritza,Tundja and Arda

The main problem in the trans-boundary river system is that heavy metal and radioactive pollution can cause long-term effects on ecosystems. Therefore the natural radioactivity and heavy metal levels in the Maritza, Tundja and Arda Rivers, common for Bulgaria and Turkey, were determined for 3 years period (2007–2010). Gross alpha, gross beta and total radium isotopes activities, uranium and heavy metal concentrations of the surface water of the rivers were investigated and also terrestrial gamma and gamma dose rate were measured. The results were compared with reported data from other countries of the world and the recommended international standards. The results gathered in this study may provide background data on the natural radioactive and heavy metal levels of these trans-boundary rivers.     

Synthesis and characterization of soft polymeric nanoparticles and composites with tunable properties

Polymeric particles comprising acrylonitrile (AN)‐based core and acrylamide derivative–based shell in the submicron range with positive and negative charges were synthesized via microemulsion polymerization. 2‐Acrylamido‐2‐methylpropane sulfonic acid (AMPS) and 3‐(acrylamidopropyl)‐trimethyl ammonium chloride (APTMACl) were used as shell‐forming charged monomers onto AN core for the synthesis of p(AN‐co‐AMPS) and p(AN‐co‐APTMACl), respectively, using an oil‐in‐water emulsion system. To tune the characteristics of the core–shell particles, AN moieties in the core were amidoximated to change the nature of the core from hydrophobic (nitrile) to hydrophilic (amidoxime) nature. Additionally, colloidal magnetite particles (Fe₃O₄) produced by chemical coprecipitation technique under alkaline and inert conditions were also included inside p(AN‐co‐AMPS) and p(AN‐co‐APTMACl) particles as dual‐responsive nanocomposites against pH and magnetic field. With the magnetic properties, AN‐based core with modifiable characteristics and acrylamide‐based polyelectrolyte shells with variable charges and sizes were further used as drug carriers. For potential targeted drug delivery application of the synthesized soft particles and their composites Naproxen and Trimethoprim were used as model drugs, and he release studies were carried in phosphate buffer saline (pH = 7.4) at ambient temperature. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Microgel,nanogel and hydrogel–hydrogel semi-IPN composites for biomedical applications: synthesis and characterization

Quaternary ammonium salt hydrogels from a cationic monomer, (3-acrylamidopropyl)-trimethylammonium chloride (APTMACl), in a variety sizes such as bulk, micro- and nano- has been prepared. The synthesis of micro- and nanogels were carried out in the microenvironment of water-in-oil microemulsions using two types of surfactants, namely, L-α- phosphatidylcholine (lecithin) and dioctyl sulfosuccinate sodium salt (AOT). Additionally, hydrogel–hydrogel composite semi-interpenetrating polymer networks (semi-IPN) was synthesized by dispersing previously prepared micro/nanogel into neutral monomers such as acrylamide (AAm) or 2-hydroxylethyl methcarylate (HEMA) before network formation. Hydrogel swelling and pH response behaviors have been investigated for bulk gels. Morphology, structure, and size of nano-, micro- and bulk materials were explored utilizing transmission electron microcopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM). It was confirmed with gel electrophoresis that completely charged nanogel form a strong complex with DNA.     

Entanglement in Ising Chain with Inhomogeneous Magnetic Field

We have numerically calculated the thermal entanglement of a two-qubit system at low temperatures in a isotropic Ising chain under an inhomogeneous magnetic field. It is shown that in the homogeneous magnetic field, the two- qubit system has entangled states. It is concluded that the presence of the inhomogeneity in the magnetic field plays an effective role on the entangled states. Finally, it is suggested that the inhomogeneity in the magnetic field can be used to create two separated entangled formations in a two-qubit system.