Papers by Keyword: X-Ray Diffraction Analysis (XRD)

Abstract: The results show the effect of polymer modification on the behavior of Ca (OH)₂ in steel fiber reinforced concrete. The polymer modified concrete were prepared using acrylic emulsion polymer at various polymer-cement ratios; they were tested for mechanical strengths, moulded into specimens and cured. The cured specimens were subjected for compressive strength, flexural strength, splitting tensile strength and modulus of elasticity. The small specimens that moulded were subjected to X-ray diffraction (XRD). From the test results, it is concluded that formation of Ca (OH)₂ in the polymer modified concrete reinforced with steel fiber is reduced possibly because of the absorption of Ca (OH)₂ on polymer films formed in the concrete. The extent of reduction in the quantity of Ca (OH)₂ depends upon the polymer-cement ratio, polymer type or both. Generally SFRPMC of mix 43 with 2.5% polymer-cement ratio were found to be more effective than other SFRPMC with 1.0% and 4.0% acrylic emulsion polymer in reducing the quantity of Ca (OH)₂ in SFRPMC. The cement modifiers did not cause any detrimental effect on the degree of hydration as in SFRPMC therefore, does not provide a proper means for predicting their degree of hydration.

Abstract: Abstract. We prepared, under vacuum and onto monocrystalline silicone and glass substrates, series of CoxCr1-x thin films, with x ranging from 0.80 to 0.88. The structural and magnetic properties of the as deposited films have been performed using Rutherford backscattering spectrometry (R.B.S.), X-ray diffraction (X.R.D.), Alternating Gradient Field Magnetometer (A.G.F.M.), and Brillouin Light Spectrometry (B.L.S.) techniques. Once the films being annealed under vacuum, for 1 h at 700°C, in a pre-heated furnace, their structural and magnetic properties have been performed, by these tools, as well. Significant results have been found. The as deposited films present only an HCP structure and show a preferred orientation. The annealed films present both HCP and FCC structures. The annealed films possess cell parameters greater than the bulk ones which infer that they are under a tensile stress. The cell parameters of the as deposited films are lower than the bulk ones which infer that they are under a compressive stress. Up to the annealing temperature the films are still ferromagnetic and some decrease of the magnetic moment is noticed. In addition, coercivity and squareness have been strongly improved in the annealed films comparatively to the as deposited films. Moreover, the stiffness constant, computed using Brillouin light scattering measurements and after adjustment of theoretical and experimental results, is found to be far lesser than pure Co one. These results and others will be presented and discussed.

Abstract: Oil palm empty fruit bunch (OPEFB) in this study was used to remove silica bodies embedded on OPEFB strands. Silica bodies were removed by sonication method at varying sonication temperature of 40, 50 and 60 °C and tested using scanning electron microscopy imaging (SEM), x-ray diffraction (XRD) and applied to an anaerobic digester to quantify biogas production. Sonication was applied using an ultrasonic cleaner, producing 40 kHz sonic wave. This paper intends to utilize and optimize OP-EFB as bio-matrices to enhance biogas production. Results showed that the highest sonication temperature; 60 °C recorded the most perforated holes on SEM image, lowest intensity at 75 CPS for XRD analysis and highest biogas production of 13,919.27 cm³.

Abstract: Aquillaria species or agarwood has principal uses as medicine, perfume and also incense. This study was mainly on the agarwood waste; the element occurs in agarwood waste with pre-treatment was examined, and the results are compared against raw agarwood and agarwood waste ash. The objective of present work is to indicate the inorganic compound available, especially silica in agarwood waste. Series of analyses was performed to study the organic and inorganic compound found in agarwood waste, as well as to determine the silica existence. The analysis involved CHN, XRD and TGA. Further study is necessary in order to develop new substitute raw material for silica gel production by using agarwood waste.

Abstract: The technique and preliminary results of in situ X-ray diffraction analysis of the martensitic transformation in the newly developed Ti-Nb-Zr SMA for biomedical application are presented. To perform the in situ analysis, an original tensile stage, powered by a Ti-Ni SMA actuator and fit within the “TTK450” thermal chamber of a “PANalytical X’Pert Pro” diffractometer is designed, manufactured and validated. The tensile stage working principle and analysis methodology are described in detail. Preliminary results obtained during in-situ X-ray analysis of the phase transformations in Ti-Nb-Zr SMA are also presented.

Abstract: Polyethylene film destruction by mixed culture of microorganisms was studied. The initial culture was adapted for growth on the media with ion exchange resin. During cultivation of the microorganisms on the mineral media with a polyethylene as the only source of carbon and energy the increase of film roughness and decrease of amorphous fraction and crystal size was detected. Using atomic-force microscopy and scanning electron microscopy it was found the film reduce to the crystals of micron size and unilamellar crystal fragments. The film relief change and crystal size decrease was detected after contact with oil-oxidizing bacteria and after composting with plant residuals with redworm Eisenia foetida.

Abstract: Using SEM observation and X-ray diffraction analysis, explore the growth mechanism of green high performance concrete strength, study the microstructure of green high performance concrete as well as the species and state of products, to prove fly ash, mineral powder and additive can greatly enhance the strength, density and durability of concrete, and finally make low-strength concrete satisfy the need of green high performance.

Abstract: The mechanism for phosphate cement hydraulic reaction is determined. The microscopic process is described by means of scanning electronic microscope, X-ray diffraction analysis,infrared spectrophotometry and differential heat analysis. The results show the three main phases are present, i.e. hydromagnesium phosphates, Mg (OH)₂ and MgO phase. The type, structure, and amount of every phase play an important role in phosphate cement properties. Hydromagnesium phosphate phase structure has a close relation to phosphate cement setting and hardening. The development of strength has much to do with the formed crystalline directing.

Abstract: A typical kind of silicate gangue — sodium pyroxenite (mainly containing NaFeSi₂O₆) in Baiyunebo iron ore is selected as the research object in this paper. The endothermic peak and the change of quality is definited by means of thermal analysis (DSC and TG) in the rising process. And then the samples are sintered at the peak temperatures. The main ingredients of sodium pyroxenite and the resultants are definited by means of X-ray diffraction analysis (XRD). The experiment ascertains the change law of physical and chemical properties of sodium pyroxenite such as thermal decomposition, softening, melting temperatures and the corresponding resultants, which provides basic data for exploring the formation mechanism of complex calcium ferrite (SFCA) in baogang special sintered ore.

Abstract: The effect of thermal cycling of the Ti - 49.8 at. % Ni alloy deformed by rolling at 500 оС on dilatation of the material was investigated. It was shown that R → B2 and B19' → B2 phase transformations take place during heating due to retaining of R-phase at the lowest temperature of cycling. The evolution and subsequent stabilization of two-way shape memory effect (TWSME) upon thermal cycling are caused by decreasing of the residual B19'- martensitic phase formed during rolling. It was revealed that recoverable strain of the alloy doesn’t exceed 0.8 % even after forty cycles.