EVALUATION OF THIN FILM COMPOSITE FORWARD OSMOSIS MEMBRANES: EFFECT OF POLYMER TYPE

In the forward osmosis (FO) processes, the semipermeable membranes are used. These membranes are prepared from several types of polymers. In this research, the characterizations of each polymer were studied to conversance the effect of polymer type on the efficiency of the forward osmosis process. The prepared membrane’s roughness was investigated using atomic force microscopy (AFM) and scanning electron microscopy (SEM) to compare the formation of the TFC polyamide selective layer on each polymer type. Also, SEM images showed the distribution of pores on the prepared membrane. Contact angle (CA) measurements explained the hydrophilic and hydrophobic properties of membrane types. Finally, Energy dispersion spectrometry (EDS) was tested to determine the type, amount, and distribution of atoms in the prepared membranes. All of these characterizations proved that the Polysulfone (PSU) polymer was the best choice in the FO process. It can be proved that by test results, the PSU membrane gave the optimal water flux and salt rejection.

Martensitic transformation behavior and structural characteristics of annealed Ni-Mn-Sn-Fe-In Heusler alloy

Ni-Mn based heusler alloy with Ni50-xFexMn30Sn20-yIny where 1<=x<=4; 2<=y<=8 are studied for their structural as well as mechanical characteristics using various testing facility such as field emission scanning electron microscope, energy dispersion spectrometry, differential scanning calorimetry and Vickers hardness equipment. From the general understanding the materials are to display a transformation of austenite-martensite. The materials are seen to be showing this transformation in and around near room temperature. The optical and FESEM imaging of the specimen show that during annealing heating to high temperature to longer time, the diffusion kinetics are activated at faster rate so that the dendritically structure is annihilated to develop well distributed grain structure. The coarser dendrites seems to be broken and fine grain, well dispersed phases are formed. X-ray diffraction confirms the peak split and martensitic transformation in the system of alloys. DSC results confirm the martensitic transformation around room temperature.

Use of Spectroscopy and Computer Simulation to the Study of Surfaces Modified by Ionic Implantation

Using X-ray Photoelectron Spectroscopy (XPS) and energy dispersion spectrometry, the phase and elemental compositions of the nanoscale surface layer of implants are studied. The method of determination of the optimal mode of nanoscale modification of the surfaces of metals and alloys by means of the ionic implantation is presented. The problem of processing the curved surfaces with mathematical calculations and a computer simulation is solved. The proposed technique is tested on synthesized implants. The sample hardness was taken as a criterion.

Effect of chemical composition on the microstructure, hardness and electrical conductivity profiles of the Bi-Ge-In alloys

In this study, the microstructure, hardness, and electrical properties of selected ternary Bi-Ge-In alloys were investigated. Isothermal sections of the Bi-Ge-In system at 25, 200, and 300 ° C were extrapolated using optimized thermodynamic parameters from the literature. The used experimental techniques include optical microscopy, X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and energy dispersion spectrometry (EDS), Brinell hardness, and electrical conductivity measurements. The results of EDS phase composition analysis were compared with the calculated isothermal sections and a good overall agreement was reached. The results of the XRD were also in line with the predicted phase balance. By using ANOVA analysis and experimental results of Brinell hardness and electrical conductivity, a mathematical model was suggested for the calculation of these properties along with all composition ranges. The appropriated mathematical model was subsequently used for the prediction of hardness and electrical conductivity throughout the whole composition range.

Improvement of the mechanical properties of nodular gray cast iron with the application of heat treatments

For this experimental study, commercial samples of nodular gray cast iron were used. Samples were subjected to different heat treatments such as quenching, tempering, and annealing. These treatments were carried out to obtain an increase in specific mechanical properties such as hardness, where the new values of this property were obtained. In this process, different laboratory tests as metallographic characterization, mechanical characterization by Brinell hardness, physical and chemical characterization by Scanning Electron Microscopy (SEM), and X-ray Energy Dispersion Spectrometry (EDS) were applied. The results obtained show that specific thermal treatments can be implemented together and different temperatures, achieving an increase of three times the value of the hardness for the manufacture of brake discs, able to withstand the thermal conditions caused during his operation.

Microstructures and hardness of as-cast {C, Ta or Ti or Hf of Zr}-containing Cr-rich Niobium-based alloys candidate for uses at elevated temperatures

Four alloys based on niobium and containing about 33wt.%Cr, 0.4wt.C and, in atomic content equivalent to the carbon one, Ta, Ti, Hf or Zr, were elaborated by classical foundry under inert atmosphere. Their as-cast microstructures were characterized by X-ray diffraction, electron microscopy, energy dispersion spectrometry and while their room temperature hardness was specified by Vickers indentation. The microstructures are in the four cases composed of a dendritic Nb-based solid solution and of an interdendritic NbCr2 Laves phase. Despite the MC-former behavior of Ta, Ti, Hf and Zr usually observed in nickel or cobalt-based alloys, none of the four alloys contain MC carbides. Carbon is essentially visible as graphite flakes. These alloys are brittle at room temperature and hard to machine. Indentation shows that the Vickers hardness is very high, close to 1000HV10kg. Indentation lead to crack propagation through the niobium phase and the Laves areas. Obviously no niobium-based alloys microstructurally similar to high performance MC-strengthened nickel-based and cobalt-based can be expected. However the high temperature mechanical and chemical properties of these alloys remain to be investigated.

Interface characterization of Cu–Mo coating deposited on Ti–Al alloys by arc spraying

Cu – Mo pseudobinary alloys are promising candidates as electrode materials in CoSb 3-based skutterudite thermoelectric (TE) devices for TE power generation. In this study, Cu – Mo coatings were deposited onto Ti – Al substrates by applying a dual-wire electric arc spraying coating technique. The microstructure of the surfaces, cross sections and coating interfaces were analyzed by scanning electron microscopy (SEM) and energy dispersion spectrometry (EDS). Cu – Mo coatings showed a typical banded splat with compact microstructures, and have no coarse pores nor micro-cracks. The thermal shock resistance of the Cu – Mo coating was also investigated to show good combinations with Ti – Al substrates. After 50 thermal shock cycles, there were no cracks observed at the interface. In contrast, the test of the thermal shock resistance of the Cu coating on the Ti – Al substrate was also investigated. Due to a large difference in the thermal expansion coefficients between Cu and Ti – Al alloys, the Cu coating flaked from the Ti – Al substrate completely after 10 thermal shock cycles. The contact resistivity of the Ti – Al / Cu – Mo interface was about 1.6 μΩ⋅cm2 and this value was unchanged after 50 thermal shock cycles, indicating the low electric resistance and high thermal stability of the Cu – Mo / Ti – Al interface.

Energy Dispersive Techniques Using X-Ray Fluorescence with Primary X-Rays for Human Hard Tissues Analysis

Among others, biomedical research is conducted for the systematic collection and analysis of data from which general conclusions can be drawn and which can increase the life quality of the patients. Given these issues, the aim of the research presented in this paper is to analyze the concentration of heavy elements from the human body, using complementary analysis methods, based on the energy dispersion spectrometry (EDS) technique.

Fabrication and Antibacterial Performance of Bio-Graded Nano-Composite Materials by Using Inkjet Printing Method

The graded composite materials were fabricated by direct inkjet printing of nano-electropolar mineral and nano-hydroxyapatite powders for the study of inhibiting function on streptococcus mutans, which is a primary pathogen for human dental caries. The electropolar mineral can be utilized in many fields due to its spontaneous permanent polarity and far infrared emission properties. In this study, the graded distribution of the streptococcus mutans on the surface of graded composite materials was investigated by energy dispersion spectrometry, and the mechanism of which is that the streptococcus mutans was remained in the culture of pH at about 8.5 self-adjustment induced by the electropolar mineral. This culture inhibits growth and acid production of streptococcus mutans. Therefore, this composite materials have inhibitory effects on streptococcus mutans, and can be used as a promising biomaterial for preventing human teeth from caries.