Biocompatibility of a new bioactive glass composition for medical applications was evaluated with the addition of fluorides, such as CaF2 and MgF2, for the substitution of Na2O in the conventional bioactive glass composition (SiO2-CaO-Na2O-P2O5). Also, the physical properties of these glass ceramics were investigated. When B2O3 was added as a Na2O substitution, the thermal expansion coefficient...

Neutron diffraction and 31P nuclear magnetic resonance spectroscopy were used to probe the structure of phosphate glass biomaterials of general composition (CaO)0.5-x(Na2O)x(P2O5)0.5 (x = 0, 0.1 and 0.5). The results suggest that all three glasses have structures based on chains of Q2 phosphate groups. Clear structural differences are observed between the glasses containing Na2O and CaO. The P-...

parent red-brown and brown single crystals, respec tively, and had average size of 3.0•~2.8•~1.1mm and 3.6•~2.8•~1.0mm. (3) The content of Li2O in all the Li doped crystals was less than 0.01wt%, whereas the Na2O content was more than 0.07wt% and increased with increasing addition of Na2O. (4) Crystals doped with Li2O showed no variations in the lattice constant, but the lattice constant of c-a...

Bioactive glasses prepared in SiO2–CaO–Na2O and P2O5 system are used as biomaterials in orthopaedic and maxillofacial surgery. Zn presents high physiological interest. It enhances physiological effects of implanted biomaterials. In this work, the thermal characteristics (Tg, Tc and Tf) of pure bioactive glass elaborated with different amounts of CaO, Na2O in pure glass and with different amount...

The fluctuation of ESR parameters which reflects the intrinsic "site-to-site fluctuation" in glass was extracted by analyzing the ESR lineshape of spin probes, Cu2+ and -induced Cd+, for the wide composition range of soda borate glasses. The results obtained are summarized as follows (i) The lineshape of Cu2+ was closely reproduced by introducing a skewed distribution function of g„into the lin...

Alkali Activated Slag Concrete (AASC) mixes are manufactured by activating ground granulated blast furnace slag (GGBFS) using sodium hydroxide and sodium silicate solutions. The aim of the present experimental research was to investigate the effect of increasing the dosages of sodium oxide (Na2O, in the range of 4 to 8%) and the activator modulus (Ms) (i.e. the SiO2/Na2O ratio, in the range of ...

three granitoid bodies, shirkuh batholith, kaffe abad and ader bolandan are exposed in nw yazd, cutting across the naiband formation (upper triassic), and overlain by cretaceous formations. shirkuh batholith is most likely of jurassic age. it seems to be the first and the most significant episode of magmatism in studied area which occurred in middle jurassic (late cimmerian) time. on the other ...

PbOを 含有す る混合 アル カ リの光学 ガ ラスのNa+_??_K+イ オ ン交換 に 及 ぼす ガラス組成 の影 響 をEPMA,光 学顕微鏡 によ り研究 した. Al2O3/Na2O比 が1.0以 下 では, この比 の増大 に とも ないイオ ン交換の速 度が増大す ることが一般 に知 られて いるが, 本研究 のPbOを 多 く含 むガラス の場合には このAl2O3/Na2O比 の効果が ほ とん ど な い ことが わか った. これ はPb2+イ オ ンが Na+_??_K+イ オ ン交換の際にK+イ オ ンの移動 を抑 え るためであろ う. しか しPbOをAl2O3で 入れ換 えてAl2O3/Na2O比 を増 大 させ る とみかけの拡散 係数 は5倍 増大 し, Al2O3/Na2Oの 比の影 響 がみ られた. した が ってPbOを 多 く含 有す ...

In present investigation, the study of gamma ray Energy absorption buildup factors (EABF) for three oxide glasses, viz. CaO-Al2O3, Na2O-SiO2, and Na2O-Al2O3-SiO2. The computations were done by ANSI/ANS-6.4.3 library and interpolation method using the Geometric Progression fitting formula for the energy range from 0.015 to 15 MeV, up to penetration depths 40 mfp (mean free path). The buildup fac...