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A facile and fast method has been developed to synthesize pure hydroxyapatite/wollastonite (HAp/WT) composite powders of different weight ratio. HAp/WT composites could be easily prepared by a two-step coprecipitation route and subsequent heating of the precipitant for 2 h, using Ca(OH) 2 and H 3PO4 as starting materials in the first step then adding Ca(NO 3) 2.4H 2O and Na 2SiO 3.9H 2O in the second...
Porous solid polysiloxane ligand systems bearing an iminodiacetic acid chelating ligand of the general formula P-IDA (where P- represents [Si-O] n polysiloxane network and IDA represent an organofunctional group) were achieved in two-step reaction. The first step includes a template synthesis of 3-iodopropylpolysiloxane (P-I) or 3-aminopropylpolysiloxane (P-MA) by hydrolytic polycondensation of TEOS...
To re-evaluate ecological effects of kelp culture in marginal seas, the silica body content in kelp cultured in the East China Sea and the carbon content in the silica body extracted from kelp were measured. The silica body content in kelp cultured in the sea ranged from 0.20 to 0.60 % and the carbon content in the silica body extracted from kelp was 0.27 ± 0.06 %. The carbon sequestration rate in...
Silicon-substituted hydroxyapatite has shown superior biological performance compared to its stoichiometric counterpart both in vitro and in vivo. In the present study, single-phase silicon-substituted hydroxyapatite was successfully synthesized by the precipitation method. Chemical composition, crystalline phase, microstructure, and morphology of the materials were characterized by XRF, XRD, FT-IR,...
In this paper we report on the characteristics of Schottky contact behavior of AlGaN/GaN High Electron Mobility Transistors (HEMTs) on a Si Substrate. A variety of electrical techniques such as capacitance-voltage (C-V) and deep level transient spectroscopy (DLTS) measurements have been used to characterize the diode. The behavior of the ideality factor n, the effective barrier height Φb, and the...
In this paper, it is shown that Ouargla region (Algeria) sand dunes are very rich in quartz. This study aims to assess the quartz in the different granular sand types, using XRD spectroscopy. Granulometric classification and the size distribution curve were carried out. The X’Pert HighScore program based on the Rietveld refinement was used in analyzing the XRD data. Qualitative and quantitative quartz...
This work has been carried out to investigate the infrared absorption spectra, of a number of alkali borate and alkali silicate glasses containing nickel oxide and/or iron oxide to investigate the structure of theses glasses. All glasses studied were melted in platinum 2 % rhodium crucibles in an electrically heated furnace at different temperature (1000 – 1400) 0C for two hours. The results are explained...
Water soluble polysiloxanes were prepared by condensation of 3-aminopropyl diethoxymethylsilane followed by the reaction of the amines with ethylene carbonate to yield carbamate side chains with terminal hydroxyl groups attached to each silicon atom in the polymer chain. The molecular weight of these carbinol functional polysiloxanes was controlled by adding known concentrations of hexamethyldisiloxane...
Phragmites communis phytoliths were extracted from the xerophytic habitat of 12 sampling sites in northeast (NE) China during June–October in 2011 and 2012. The changes of P. communis phytolith concentrations in different temperature zones and growth stages were used to reveal the ecological environmental significance of P. communis phytoliths. The purpose of the study is to provide a scientific reference...
The occurrence of a photonic band gap modulation in the periodic arrangement of a Si-SiO2 layer, in the presence of in-plane acoustic plate symmetric modes is studied. The proposed structure shows simultaneous existence of photonic band gaps in the infrared region and phononic band gaps in the GHz frequency range. Due to the presence of photonic band gaps and phononic band gaps, this arrangement is...
The usage of hybrid natural composites has surged in almost all fields of engineering due to their advantage of possessing high strength to weight ratio and biodegradability. This paper deals with the fabrication and investigation of mechanical and thermal properties of banana-kenaf glass fiber reinforced epoxy composite which is relatively a newer hybrid composite. In this study, the composite is...
An efficient method for C-N bond formation via aza-Michael addition of γ-aminopropylsilatranes to substituted N-phenylmaleimides under mild conditions is described. The five receptors enclosing the maleimide moiety have been synthesized by the aza-Michael addition to strong nucleophile γ-aminopropylsilatrane producing silatranes possessing substituted N-phenylsuccinimide at the axial position without...
Poly(dimethylsiloxane- co-methyl-hydridosiloxane) (PDMSMHS) with a OSi(CH 3) 2/OSi(HCH 3) molar ratio of 21:1 was functionalized with dimethylallylamine (DMAA) via catalytic hydrosilylation using Karstedt’s catalyst and then quaternized with 1-iodooctane. The functionalized and quaternized co-polysiloxanes (PDMSMHS-1 and PDMSMHS-QAS) were characterized using 1H, 13C and 29Si NMR. The physicochemical...
Phosphorus doped micro/nano crystalline silicon thin films have been deposited by the filtered cathodic vacuum arc technique at different substrate temperatures (Ts) ranging from room temperature (RT) to 350 ∘C. The films have been characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy, secondary ion mass spectroscopy, dark conductivity ( σD), activation energy...
In this study, organosilicon micro/nanocolorants were synthesized via a simple sol-gel process using dye precursors with tetraethyl orthosilicate (TEOS) under mild preparation conditions. This method presents an important approach to developing organic/inorganic hybrid micro/nanocolorants. The morphology and narrow distribution properties of the micro/nanocolorants were analyzed by scanning electron...
Alpha and beta wollastonite can serve as alternative low-cost bioceramics for bone repair and drug delivery. However, it has been challenging to develop energy-saving, facile and rapid synthetic methodologies for bioactive wollastonite phases. The aim of this work was the rapid preparation and characterization of bioactive α- and β-wollastonite powders by a coprecipitation method and their in-vitro...
New types of tellurite glass ceramics were prepared and studied from the viewpoint of bioactivity. The obtained results were compared with those of silicate glass ceramics. The crystallization behaviors of both silicate and tellurite glass ceramics with equal ratio of CaO/P2O5 were investigated. The silicate glass samples were transformed to glass ceramics by a thermal treatment process. While the...
In this study, bioactive glass of the type SiO2–CaO–SrO–P2O5 was obtained by the sol-gel processing method and the effects of SrO/CaO substitution on the in vitro biological properties of the synthesized glasses were evaluated. The obtained bioactive glasses were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermal gravimetric...
Porous silicon (p-Si), prepared by two routes (metal induced etching (MIE) and laser induced etching (LIE)) have been studied by comparing the observed surface morphologies using SEM. A uniformly distributed smaller (submicron sized) pores are formed when MIE technique is used because the pore formation is driven by uniformly distributed metal (silver in present case) nanoparticles, deposited prior...
The optical absorption spectra of undoped soda lime silicate glass together with two glasses doped with either (1 % nano Fe2O3 ) or with both (1 % Nano Fe2O3 + 5 % cement dust) have been measured from 200 to 2400 nm before and after gamma irradiation with a dose of 8 Mrad. The undoped glass reveals strong UV absorption with two distinct peaks which are attributed trace ferric iron ions present as...
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