Material Composition of Greenstone Acquisition and Use in the Jovel Valley, Chiapas, Mexico

A collection of green earths belonging to traditional artists’ pigments was examined in terms of mineralogy and provenance. The studied specimens included both mineralogical reference compounds and selected commercially available artists’ pigments, and contained green micas (glauconite or celadonite), chlorite, or smectite as pigmenting agents. The samples were examined by X-ray diffraction, Mössbauer spectroscopy, infrared (IR) spectroscopy, ultraviolet-visible (UV-Vis)-near-IR diffuse-reflectance spectroscopy and voltammetry of microparticles. Particular attention was paid to the Kadaň green earth, mined until the 20th century in the West Bohemia deposit. The Greene-Kelly charge-reduction test, detailed description of non-basal diffraction patterns and characteristic vibrations in the mid-IR spectra were used to classify the major pigmenting agent of the Kadaň green earth as ferruginous smectite with separately diffracting saponite-like clusters. The smectite contains ∼15% Fe, mainly in the trivalent form, a detectable fraction of Fe in tetrahedral sites, and it is accompanied by a significant amount of Ti-bearing relict minerals due to its volcanogenic origin. On the contrary, in green micas (glauconite and celadonite) the Ti content is much smaller. Diffuse reflectance spectroscopy was found suitable for distinguishing Fe as a constituent of free Fe oxides from Fe in the clay structure. It was also found to be useful for discriminating between green micas and smectites.

The results of seven months of archaeological reconnaissance in the Tzeltal-Tzotzil-speaking area of Chiapas are described. Occupation is found to have consisted only of a few, small, widely dispersed centers during the Preclassic period. During the latter part of the Early Classic period there is evidence of a considerable increase in population, and by Late Classic times nucleated ceremonial-dwelling centers were widely distributed on steep, easily defended headlands. Despite great variation in the size of individual settlements, it is argued that independent communities rather than regional coalitions were the prevailing form of socio-political organization. This pattern was replaced gradually during the Postclassic period by one in which more intensive use was made of the larger, more strategically located valleys. Closely spaced, functionally interdependent groups of communities emerged, and probably were increasingly subject to new and more coercive patterns of political, as well as religious, control. At the time of the Spanish conquest hostilities and trade with other Mesoamerican groups were increasing rapidly, but the region as a whole still remained relatively tarriant and isolated.

High voltage transformer is an essential power apparatus that determine the reliability and continuity of power transmission and distribution system. It comprises solid and liquid insulating materials. Kraft paper as solid insulation should have an ability to insulate the winding connection, while oil transformer, aside of its main function as insulation, it is also used as a coolant. This paper analyzes the accelerated thermal aging performance of kraft paper immersed in the natural ester from RBD palm oil by using X-Ray Diffraction (XRD) characterization. XRD characterization was used to determine the existence of crystalline structure in kraft paper. Crystalline structure in kraft paper is composed by cellulose. The toughness of kraft paper was determined by its amorphous region, lignin, that bind the cellulose and make them hard. The influence of thermal expansion was observed to discover the effect of thermal stress to the crystallinity of kraft paper. Besides, thermal degradation characteristics of kraft paper were examined by using thermogravimetric analysis. The sample was aged in 120°C and 150°C for two weeks. The results also show that crystalline region of the sample that heated in higher aging temperature tends to drop faster than the sample with lower aging temperature.

Silica from pumice natural rock was extracted by varying HCl of 1M and 2M. Fristly, pumice was heated to 400°C for 4 hours to activate the component of material.Three steps were used in obtaining pure silica. Silica extraction by using NaOH, silica titration by using H 2 SO 4 , and purification silica with HCl. The purified powder was calcined at 800°C. The characterization of XRD (X-Ray Diffraction) and SEM-EDS (Scanning Elektron Microscopy - Energy Dispersive Spectrometry) were performed for samples after and before purification to know the phase structure and microstructure and pumice powder content. The XRD results was show diffraction pattern of the amorphous shaped SiO 2 with some crystalline peaks is an other oxide compound than SiO 2 for the starting material, and an anorite crystal phase in the HCl 1M and 2M variations. This is confirmed by EDS results what showing the silica content has the highest percentage of 65.88% for the raw material, 67.83% for HCL 1M and 69.63% for HCl 2M variation after purification. While the SEM results identified the microstructure for the raw material has a clear but not entirely homogeneous that is the identification of the sample in an amorphous state, whereas the sample after purification of the microstructural result shows non-homogeneous grain size, unclear grain boundary boundaries and an algomeration (agglomeration ) which is also the identification of the sample in an amorphous state. Silica from pumice natural rock was extracted by varying HCl of 1M and 2M. Fristly, pumice was heated to 400°C for 4 hours to activate the component of material.Three steps were used in obtaining pure silica. Silica extraction by using NaOH, silica titration by using H 2 SO 4 , and purification silica with HCl. The purified powder was calcined at 800°C. The characterization of XRD (X-Ray Diffraction) and SEM-EDS (Scanning Elektron Microscopy - Energy Dispersive Spectrometry) were performed for samples after and before purification to know the phase structure and microstructure and pumice powder content. The XRD results was show diffraction pattern of the amorphous shaped SiO 2 with some crystalline peaks is an other oxide compound than SiO 2 for the starting material, and an anorite crystal phase in the HCl 1M and 2M variations. This is confirmed by EDS results what showing the silica content has the highest percentage of 65.88% for the raw material, 67.83% for HCL 1M and 69.63% for HCl 2M variation after purification. While the SEM results identified the microstructure for the raw material has a clear but not entirely homogeneous that is the identification of the sample in an amorphous state, whereas the sample after purification of the microstructural result shows non-homogeneous grain size, unclear grain boundary boundaries and an algomeration (agglomeration ) which is also the identification of the sample in an amorphous state.

Extended and local structural description of a kaolinitic clay, its fired ceramics and intermediates: An XRD and XANES analysis

All cellulose composites based on cellulose diacetate and nanofibrillated cellulose prepared by alkali treatment

Synthesis of LiNiO 2 in air atmosphere: X-ray diffraction characterization and electrochemical investigation

Hydrochloric acid (HCl) is commonly removed from flue gases using hydrated lime (Ca(OH)2) as a sorbent in the dry scrubbing process. Although this method is relatively easy to operate and the lime sorbent is cheap, this process is highly inefficient, as only ∼25% of the lime used is converted, due to the short contact time and the lack of understanding of the reaction chemistry of lime in a complex flue gas system. A comprehensive X-ray diffraction (XRD) characterization was carried out on the product of a hydrated lime reaction with HCl in a simulated flue gas system containing SO2, CO2, O2, and moisture. Together with thermodynamic calculations, the chemical nature of the multiple reactions that happened in this system was investigated. It was confirmed that the products of hydrated lime with HCl under the simulated flue gas conditions were chiefly Ca(OH)Cl, CaCl2, CaCO3, CaSO3·1/2H2O, CaSO4·2H2O, and anhydrous CaSO4. Previous results suggested that the presence of CO2 and SO2 in the system formed products with a high product diffusion resistance, leading to pore blockage and the premature termination of the reaction. However, in this study, experimental proofs showed that HCl was able to break down the CaCO3 and CaSO3·1/2H2O layer, allowing the reaction to continue. In the presence of excess O2 (and moisture), part of the CaSO3·1/2H2O was oxidized to CaSO4·2H2O and CaSO4. The presence of O2 is, therefore, counterproductive to the full utilization of hydrated lime, as sulfur in its S(VI) form is more stable and resistant to HCl attack, thereby preventing blocked pores from being cleared.

This research examines the mechanical, morphological, and moisture assimilation of composite materials built up from sugarcane bagasse fiber (SBF), rice husk (RH), and wood powder (WP) filler. Regular threads are now regarded as eco-friendly materials because of their sustainability. This article’s goal is to choose between two polymer structures with fiber and matrix: case 1 has epoxy (50%) plus sugarcane bagasse fiber (30%–45%) and wooden powder (5%–20%); case 2 has epoxy (50%) plus sugarcane fiber (30%–45%) plus rice husk (5%–20%). The impact of the mechanical test is compared to obtaining the best fiber volume fraction (Vf), and the failure of cracked surfaces and interfacial bonding analysis is done using SEM as a consequence of matrix cracking, void content, and fiber pullout. In order to get the characterization of materials, Thermo-Gravimetric Analysis (TGA) and X-Ray Diffraction (XRD) analyses were also performed. However, Sugarcane Bagasse Fiber, a single fiber, combined with an epoxy composite matrix demonstrated a strength of 14 to 18 Mpa and 230 to 250 g of weight. Nevertheless, when SBF was combined with hybrid materials like Rice Husk and Wood Powder, it demonstrated superior strength, with an estimate of 16 to 20 Mpa and a weight of 220 to 240 g.

A unique instrument for the x-ray diffraction (XRD) characterization of crystalline materials has been developed and is being applied to a number of studies of metallic components. The instrument is based upon a unique position sensitive scintillation detector (PSSD) for x-rays. The methodology for the application of this instrument to the single-exposure technique (SET) of x-ray stress measurement is described. A number of applications of the device to residual stress measurement and qualitative cold work damage assessment in metallic components are discussed and data from these applications presented. Also, the application of the PSSD instrument to texture measurement is described.

All‐Solid‐State Cable‐Type Supercapacitors with Ultrahigh Rate Capability

Two reference materials containing platinum-group metals have been certified as standards. A concentrate from an alluvial material (containing platinum alloys) from the Tulameen River area of British Columbia has been analyzed for platinum; a nickel-copper matte from the Sudbury area of Ontario has been analyzed for platinum, palladium, rhodium, and gold. The sample preparation and characterization of the reference materials are described and a statistical evaluation of the "round-robin" analytical values has been performed. These reference standards are now available from the Mineral Sciences Division, Mines Branch, Department of Energy, Mines and Resources, Ottawa. A program for analyzing the nickel-copper matte for iridium, ruthenium, silver, and, possibly, osmium is to be undertaken. If sufficient satisfactory results are obtained, these constituents will also be certified for this material.

The objective of this research is to synthesize nano sodium alginate-ZnO nanocomposite as photocatalyst to degrade methylene blue compounds. The successful synthesis of nano sodium alginate-ZnO nanocomposite was supported by the characterization of XRD (X-Ray Diffraction), FTIR (Fourier Transform Infrared), SEM (Scanning Electron Microscope) and TEM (Tunneling Electron Microscope). The first stage of the research was the synthesis of nano sodium alginate with particle size 140 nm and crystallinity index 38.78 % by XRD and TEM characterization, the obtained particle size was 146 nm × 61 nm. Nano ZnO particle size 38 nm, by XRD and TEM characterization the obtained particle size was 56.6 nm × 33.3 nm. The next stage of nanocomposite synthesis of nano sodium alginate was the impregnation with nano ZnO particle size 130 nm, by XRD and TEM characterization the particle size was 228.0 nm × 134.2 nm. The success was also supported by FTIR and SEM characterization. The final stage was the degradation of blue methylene using nano-sodium alginate-ZnO nanocomposite. The highest degradation percentage by nano sodium alginate-ZnO nanocomposite with zinc nitrate concentration of 0.075 M was 51.68% with the first order rate constant of 9.5 = 10−3 /min.

TPR, XRD and XPS characterisation of ceria-based materials synthesized by freeze-drying precursor method

Correction to: R.H. Bragg: An African American Pioneer in X-Ray Crystallography, X-Ray Diffraction, and Materials Characterization