Materials Literature
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The structural properties, thermal stability, thermal expansion, and electrical properties of the RBaCuFeO 5+δ (R = Y, La, Pr, Nd, Sm-Lu) layered ferrocuprates have been studied systematically. The linear thermal expansion coefficients of the RBaCuFeO 5+δ phases are ≃ 13 × 10 −6 and ≃ 13 × 10 −6 K −1 for R = La-Eu and…
A mechanical model of liquid crystals (LCs) is applied to study the polymorphism of homologous series of terphenyl compounds. With a semi-experimental molecular orbit method, we calculate the moment of inertia which represents the rotation state to describe the phase transition temperature obtained from experimental d…
Effect of ZnO, SrO, and La 2 O 3 additions on properties of lead zirconate titanate (PZT) nanopowder were investigated. Our objective was to densify PZT near 900°C to reduce lead loss and increase processing compatibility of these materials with IC fabrication technique for micro‐electro‐mechanical systems (MEMS). PZT…
We have designed novel liquid crystal oligomers in which three mesogenic units are connected via 3,5‐dihydroxybenzoic acid. 4‐Cyanobiphenyl‐4′‐yl 3,5‐bis{6‐[4‐(5‐octylpyrimidin‐2‐yl)phenyloxy]hexyloxy}benzoate and 4‐(5‐octylpyrimidine‐2‐yl)phenyl 3,5‐bis{6‐[4‐(5‐octylpyrimidine‐2‐yl)phenyloxy]hexyloxy}benzoate have be…
In this study, the oxidative polycondensation reaction conditions of 4-[(2-hydroxybenzylidene)amino]benzoic acid (4-HBAB) by using oxidants such as air O2, H2O2 and NaOCl were studied in an aqueous alkaline medium between 40 and 90 °C. The structures of the synthesized monomer and oligomer were confirmed by FT-IR, UV–…
The EPI—D diatom index was used in monitoring seven rivers situated in the central-eastern Apennine sector (Italy) in agreement with the European Directive, WFD/60/2000/EC, which encourages all member states to use available instruments in order to assess the ecological status of rivers, including algae. This index is…
PbS nanocrystals (diameter of 5–7nm) were synthesized via sulfur ion implantation in Pb-based glasses and postannealing. They display strong emission at around 1.5μm due to quantum confinement, and a very large photoluminescence (PL) excitation cross section. The PL intensity and decay rate temperature dependences pro…
Classical molecular dynamics simulations are carried out to analyze the physical state of the catalyst, and the growth of single-wall carbon nanotubes under typical temperature and pressure conditions of their experimental synthesis, emphasizing the role of the catalyst/substrate interactions. It is found that a stron…
Biocompatible polysuccinimide (PSI) derivatives conjugated with diethylenetriaminepentaacetic acid gadolinium (DTPA-Gd) were prepared as magnetic resonance imaging (MRI) contrast agents. In this study, we synthesized PSI derivatives incorporating methoxy-poly(ethylene glycol) (mPEG) as hydrophilic ligand, hexadecylami…
We demonstrate the ability of N,N-diethylphenylazothioformamide and N,N-bis[tetra(ethylene glycol)monomethyl ether]phenylazothioformamide ligands to dissolve the four transition metals: palladium, copper, nickel and platinum. The method allows solubilisation and quantitative analysis of the transition-metal content i…
Silicon oxycarbide glasses (Si/C/O) of various compositions have been obtained after pyrolysis of polysiloxane gels produced by the sol–gel method. Four gels were synthesized from various structures of silicon precursors: MTES issued from methyltriethoxysilane CH 3 Si(–OEt) 3 , VTES from vinyltriethoxysilane CH 2 =CH–…
A new strategy to prepare and precisely assemble small gold nanoparticles in true one-dimensional lines is reported. This template-free technique allows one to control the nanoparticle size and interparticle distances, while precisely positioning the large scale 1-D assemblies on the surface.
Extruded round bars from magnesium alloys ZM21, ZK30, ZE10 and ZEK100 with various grain sizes were tested in tension and compression. The effect of grain size on the deformation behaviour of the alloys was investigated through the Hall‐Petch relation. In‐situ acoustic emission measurements were conducted during testi…
A model of the arc discharge used for a single wall carbon nanotube (SWNT) synthesis is developed. Coupling solution of the non-equilibrium, Knudsen layer, with hydrodynamic layer and discharge column provides self-consistent solution for the ablation rate and plasma parameter distribution. It is predicted that the in…
A new low-temperature, one-pot method is introduced for the preparation of organically passivated HgTe nanocrystals, without the use of highly toxic precursors. The nanocrystals show bright photoluminescence in the infrared telecommunication windows about 1300 and 1550 nm with quantum efficiencies between 55 and 60%.…
CdTe nanoparticles stabilized by l-cysteine are chemically transformed into CdS nanoparticles of the same diameter via an intermediate CdTeS alloy without any auxiliary source of sulfur. The reaction is induced by ethylenediaminetetraacetic acid dipotassium salt dehydrate (EDTA), which was demonstrated experimentally…
Very shortly following the discovery of single-walled carbon nanotubes laser-based methods emerged as reliable ways to produce moderate quantities with very consistent composition and properties. They have also proven to be good platforms for the systematic investigation of various synthesis parameters in the hope of…
In this paper, we summarize some of the key data gaps, uncertainties, and unknowns that need to be addressed to develop adequate risk assessments for nanomaterials. We make recommendations to take timely and appropriate public health precautions. We also briefly discuss nanotechnology applications for food and food pa…
We present a computational analysis of the flow of liquid foam along a smooth wall, as encountered in the transport of foams in vessels and pipes. We concentrate on the slip of the bubbles at the wall and present some novel finite element calculations of this motion for the case of fully mobile gas/liquid interfaces.…
A novel approach to design digital phase shifters with the operational bandwidth extended to one octave is presented. An original design of the broadband phase shifter based on switching between transmission lines (TLs) with positive and negative dispersions is considered. An artificial TL with the negative dispersion…