SYNTHESIS, MICROSTRUCTURE AND MECHANICAL PROPERTIES OF Mg - 5Zn - 0.3Ca/nHA NANOCOMPOSITES

Recently, magnesium and its alloys have attracted great attention for use as biomaterial due to their good mechanical properties and biodegradability in the bio environment. In the present work, nanocomposites of Mg - 5Zn - 0.3Ca/ nHA were prepared using a powder metallurgy method. The powder of Mg, Zn and Ca were firstly blended, then four different mixtures of powders were prepared by adding nHA in different percentages of 0, 1, 2.5 and 5 %wt. Each mixture of powder separately was fast milled, pressed, and sintered. Then, the microstructure and mechanical properties of the fabricated nanocomposites were investigated. The XRD profile for nanocomposites showed that the intermetallic phases of MgZn2, MgZn5.31 and Mg2Ca were created after sintering and the SEM micrographs showed that the grain size of nanocomposite reduced by adding the nHA. The nano composite with 1wt. % nHA increased the density of Mg alloy from 1.73 g/cm3 to 1. 75 g/cm3 by filling the pores at the grain boundaries. The compressive strength of Mg alloy increased from 295MPa to 322, 329 and 318MPa by addition of 1, 2.5 and 5wt. % nHA, respectively

Experimental study and nuclear model calculation for 65Zn production

Excitation functions and theoretical yields via charge particle induced reactions were evaluated using EMPIRE-3.2.2 and ALICE/ASH codes and the obtained results have been discussed and compared with the available reported experimental data. It has been verified that natCu(p,n)65Zn reaction is the optimum 65Zn production route. The 65Zn was produced using natCu(p,xn) 65Zn reaction in the energy range of 16.8 � 12.2 MeV with the thick target yield of 0.15 ± 0.005 MBq/μA h. The 65Zn radionuclide was purified by anion exchange chromatography. © 2017, Akadémiai Kiadó, Budapest, Hungary

Experimental study and nuclear model calculation for 65Zn production

Excitation functions and theoretical yields via charge particle induced reactions were evaluated using EMPIRE-3.2.2 and ALICE/ASH codes and the obtained results have been discussed and compared with the available reported experimental data. It has been verified that natCu(p,n)65Zn reaction is the optimum 65Zn production route. The 65Zn was produced using natCu(p,xn) 65Zn reaction in the energy range of 16.8 � 12.2 MeV with the thick target yield of 0.15 ± 0.005 MBq/μA h. The 65Zn radionuclide was purified by anion exchange chromatography. © 2017, Akadémiai Kiadó, Budapest, Hungary

Experimental study and simulation of 63Zn production via proton induce reaction

The 63Zn was produced by16.8 MeV proton irradiation of natural copper. Thick target yield for 63Zn in the energy range of 16.8 �12.2 MeV was 2.47 ± 0.12 GBq/μA.h. Reasonable agreement between achieved experimental data and theoretical value of thick target yield for 63Zn was observed. A simple separation procedure of 63Zn from copper target was developed using cation exchange chromatography. About 88 ± 5 of the loaded activity was recovered. The performance of FLUKA to reproduce experimental data of thick target yield of 63Zn is validated. The achieved results from this code were compared with the corresponding experimental data. This comparison demonstrated that FLUKA provides a suitable tool for the simulation of radionuclide production using proton irradiation. © 2018 Elsevier Lt

Experimental study and simulation of 63Zn production via proton induce reaction

The 63Zn was produced by16.8 MeV proton irradiation of natural copper. Thick target yield for 63Zn in the energy range of 16.8 �12.2 MeV was 2.47 ± 0.12 GBq/μA.h. Reasonable agreement between achieved experimental data and theoretical value of thick target yield for 63Zn was observed. A simple separation procedure of 63Zn from copper target was developed using cation exchange chromatography. About 88 ± 5 of the loaded activity was recovered. The performance of FLUKA to reproduce experimental data of thick target yield of 63Zn is validated. The achieved results from this code were compared with the corresponding experimental data. This comparison demonstrated that FLUKA provides a suitable tool for the simulation of radionuclide production using proton irradiation. © 2018 Elsevier Lt

Polymeric ionic liquids with mixtures of counter-anions: a new straightforward strategy for designing pyrrolidinium-based CO2 separation membranes

Polymeric ionic liquids (PILs) are interesting membrane materials for CO2 separation. In order to increase the flexibility in tailoring the permeability and selectivity of PIL-based membranes for flue gas separation and natural gas purification, this work explores the use of PILs with mixtures of counter-anions employing a straightforward strategy. A new family of PIL random copolymers having pyrrolidinium cation pendant units combined with different counter-anion mixtures was synthesized and characterized. A simple and quantitative anion exchange procedure was successfully applied to the commercially available poly(diallyldimethylammonium) chloride as confirmed by NMR, FTIR and titration experiments. Composite membranes of the copolymers with 20 wt% of free ionic liquid ([pyr(14)][NTf2]) were prepared and their CO2, CH4 and N-2 permeation properties were measured at 20 degrees C using a time-lag apparatus. In addition, their tensile mechanical properties were also assessed. The results show that the permeability of all gases in the composite membranes is related to their gas diffusivities which are strongly dependent on the second counter-anion. The prepared membranes exhibit permselectivities ranging from 10.8 to 29.3 for CO2/CH4 and from 21.4 to 32.0 for CO2/N-2. Furthermore, their CO2 separation performance as a function of permeability can be tuned by using PILs with different counter-anion mixtures, which opens new possibilities for designing the CO2 separation of these materials

Recent advances in biomaterials for tissue-engineered constructs: Essential factors and engineering techniques

Tissue-engineered constructs can replicate the structural and physiological properties of natural tissues. The constructs can be designed to address the transplantation issues affected by the shortage of donor tissues and organs. One of the major concerns in tissue engineering is the design and development of structures that improve the interaction between materials and cells and provide an ideal platform for cells to form functional tissue. Several contributing factors need to be considered to design and fabricate the constructs, including biomaterials, biological, topographical, biophysical, and morphological factors either alone or in combination. Here, we review the application, advancement, and future directions of these essential factors in designing and developing constructs for tissue regeneration. In particular, we focus on original approaches and engineering tools to design construct parameters in tissue engineering