Compositional study of prehistoric pigments (Carriqueo rock shelter, Argentina) by synchrotron radiation X-ray diffraction

2010 ◽  
Vol 25 (3) ◽  
pp. 264-269 ◽  
Author(s):  
Cristina Vázquez ◽  
Oscar Martín Palacios ◽  
Larysa Darchuk ◽  
Lué-Merú Marcó Parra

In this work synchrotron radiation X-ray diffraction technique was successfully applied for the analysis of pigments found in excavation at Carriqueo rock shelter, Neuquén, Argentina. The pigment samples of orange, red, and brown shades were collected from different levels of this archaeological site and compared with a suspected source of provenance (La Oficina creek). X-ray diffraction patterns of several yellowish, reddish, and red pigments showed the presence of haematite, goethite, kaolinite, and quartz. The majority of Carriqueo collected samples belonged to the same group of the suspected source, having haematite and quartz as main crystalline phases. The results indicate that the raw material from La Oficina is the source of most of the pigments found at Carriqueo. The present work helps us to understand the strategy of supplying raw materials by human groups in the North Patagonia region.

2007 ◽  
Vol 7 (2) ◽  
pp. 525-529 ◽  
Author(s):  
Bo Zhou ◽  
Jun-Jie Zhu

A chemical co-reduction route in aqueous solution was developed to synthesize Bi100−xSbx alloys at room temperature. The hydrolyses of Bi(III) and Sb(III) were effectively avoided by selecting proper raw materials and coordinator. X-ray diffraction analysis indicated that the as-prepared Bi100−xSbx alloys were homogeneous and phase-pure, and the Bi/Sb ratios in the alloys were very close to those in the aqueous solutions. The transmission electron microscope observation showed that the as-prepared Bi100−xSbx (x = 0∼100) alloys were particles with a size of tens of nanometers. The selected area electron diffraction patterns confirmed the high crystallinity, the homogeneousness, and the composition controllability of as-prepared alloys. All these characters and the nanometer-scaled size of the alloys are believed to be beneficial to the thermoelectric property of the Bi100−xSbx alloys.


Geosciences ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 172 ◽  
Author(s):  
Michela Ricca ◽  
Giuseppe Paladini ◽  
Natalia Rovella ◽  
Silvestro Antonio Ruffolo ◽  
Luciana Randazzo ◽  
...  

This work focused on the study of decorated pottery dated back to the 16th century from the Roman archaeological site of Villa dei Quintili, a monumental complex located in the south-eastern part of Rome (Italy). A minero-petrographic and geochemical study was undertaken to analyse five archaeological samples in order to define textural features and raw materials used for their production, along with the chemical and physical composition of the superficial decorative glazed coatings. For this purpose, different analytical methods were used, such as polarising optical microscope (POM), X-ray diffraction (XRD), micro-Raman spectroscopy, X-Ray fluorescence (XRF), and electron microprobe analysis coupled with energy dispersive spectrometry (EMPA-EDS). The results of such a multidisciplinary approach allowed us to achieve important results crucial to recognise the shards as majolica of the Renaissance period, improving knowledge about manufacturing processes of these renowned painted ceramic artefacts.


Author(s):  
Jennifer E. Readman ◽  
Alistair Lennie ◽  
Joseph A. Hriljac

The high-pressure structural chemistry of α-zirconium phosphate, α-Zr(HPO4)2·H2O, was studied usingin-situhigh-pressure diffraction and synchrotron radiation. The layered phosphate was studied under both hydrostatic and non-hydrostatic conditions and Rietveld refinement carried out on the resulting diffraction patterns. It was found that under hydrostatic conditions no uptake of additional water molecules from the pressure-transmitting medium occurred, contrary to what had previously been observed with some zeolite materials and a layered titanium phosphate. Under hydrostatic conditions the sample remained crystalline up to 10 GPa, but under non-hydrostatic conditions the sample amorphized between 7.3 and 9.5 GPa. The calculated bulk modulus,K0= 15.2 GPa, showed the material to be very compressible with the weak linkages in the structure of the type Zr—O—P.


Cerâmica ◽  
2016 ◽  
Vol 62 (362) ◽  
pp. 157-162 ◽  
Author(s):  
T. M. Mendes ◽  
G. Morales ◽  
P. J. Reis

Abstract Nowadays, environmental codes restrict the emission of particulate matters, which result in these residues being collected by plant filters. This basaltic waste came from construction aggregate plants located in the Metropolitan Region of Londrina (State of Paraná, Brazil). Initially, the basaltic waste was submitted to sieving (< 75 μm) and the powder obtained was characterized in terms of density and particle size distribution. The plasticity of ceramic mass containing 0%, 10%, 20%, 30%, 40% and 50% of basaltic waste was measured by Atterberg method. The chemical composition of ceramic formulations containing 0% and 20% of basaltic waste was determined by X-ray fluorescence. The prismatic samples were molded by extrusion and fired at 850 °C. The specimens were also tested to determine density, water absorption, drying and firing shrinkages, flexural strength, and Young's modulus. Microstructure evaluation was conducted by scanning electron microscopy, X-ray diffraction, and mercury intrusion porosimetry. Basaltic powder has similar physical and chemical characteristics when compared to other raw materials, and contributes to ceramic processing by reducing drying and firing shrinkage. Mechanical performance of mixtures containing basaltic powder is equivalent to mixtures without waste. Microstructural aspects such as pore size distribution were modified by basaltic powder; albite phase related to basaltic powder was identified by X-ray diffraction.


2011 ◽  
Vol 383-390 ◽  
pp. 3291-3297
Author(s):  
Shiao Zhao ◽  
Bo Lin Wu ◽  
Shuo Qin ◽  
Yan Rong Zhao ◽  
Zu Sheng Hu

In order to explore the effect of removing siliceous components on acid resistance of fracturing proppants, acid resistance of fracturing proppants in a new silicon-free system was studied in this paper. The fracturing proppants were made by pressureless sintering using high-purity alumina and barium carbonate as the basic raw material. Acid resistance test was carried out in 12 wt% HCl + 3 wt% HF at 65 oC for 30 minutes according to The Petroleum and Gas Industrial Standards of China (SY/T5108-2006) and morphology, structure and chemical analysis of the samples were investigated using X-ray diffraction and scanning electron microscopy. Experiments show that fracturing proppants that contain barium aluminates have better acid resistance. The acid solubility of the samples is less than 3%, especially when the content of barium carbonate is about 10% (mass fraction, the same below), the acid solubility of the sample reaches 0.52% which is far beyond the demands (5%) of the Standards of SY/T5108-2006. Results prove that the removal of siliceous components of raw materials can prominently improve the acid resistance of fracturing proppants. It can provide a new referential thought for improving the acid resistance of fracturing proppants.


2018 ◽  
Vol 143 ◽  
pp. 02006
Author(s):  
Daria Vasileva ◽  
Egor Protodiakonov ◽  
Anastasia Egorova ◽  
Svetlana Antsupova

Durability of hardened cement paste depends on chemical and mineralogical composition of Portland cement. The main factor for hardened cement paste is higher content of calcium aluminate and free calcium hydroxide, binding of which into water-insoluble compounds causes increase in resistance to water, frost and corrosion. The purpose of this research is to develop modifying admixtures to cement compositions based on local raw material - rock sand. Chemical and mineralogical properties of the source materials were studied using X-ray spectroscopy and X-ray diffraction analysis. Standard methods were used for defining physico-mechanical properties of sand and binder. Influence of the degree of mechanochemical activation of modifying admixture on the properties of binder and hardened cement paste made on its basis was studied. Research methods of scanning electron microscopy and spectral measurements were applied. The possibility of using admixture based on rock sand as a modifier was determined, its usage providing increase of strength, sulphate and frost resistance, which causes higher durability of cement concrete.


2018 ◽  
Vol 16 ◽  
Author(s):  
Zuliskandar Ramli ◽  
Muhammad Nu'man Mohd Nasir ◽  
Abdul Latif Samian ◽  
Nor Zalina Harun ◽  
Mohd Shamsul Bahari Abdul Hadi ◽  
...  

XRD and XRF analysis on the ancient bricks were conducted to identify whether the raw materials to produce the bricks originate from the site. Candi Kampung Baru is recorded as one of the temple that used bricks as the main construction material. This site is suggested to be built between the 8th to 10th centuries AD based on the size of the bricks and imported ceramics associated with the structure. The position of this candi that is facing to the north is a major indication that the candi in Kampung Baru Site is one of the many Buddhist candis that have been found in Bujang Valley. This study used X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD) analysis techniques to identify the composition of the major and trace elements and minerals found in the bricks. The results of the analysis on the ancient brick of Candi Kampung Baru revealed that the mineral content contained in the brick samples consists of quartz, muscovite, microcline and sanidine. Minerals found suggest that open burning technique was used during the brick making process with the local raw clay sources were used to produce the bricks. The results therefore implied that the participation of the local communities in Old Kedah Kingdom contributed to the prosperity of this region.


2014 ◽  
Vol 1077 ◽  
pp. 135-138
Author(s):  
Luiz Oliveira Veriano dalla Valentina ◽  
Marilena Valadares Folgueras ◽  
Wanessa Rejane Knop ◽  
Maria Cristina Pacheco do Nascimento ◽  
Glaucia Aparecida Prates

As the raw materials used in the ceramic materials manufacturing are natural, it is important to use them as a alternative materials, thus decreasing the elements demand taken from nature. This paper aims the characterization of foundry solid powder exhaust from a brazilian company located in Joinville - SC as an alternative raw material for ceramic coating by X-ray diffraction (XRD), thermal analysis (DSC) and thermogravimetric (TG). The dust depletion is caused in the manufacturing mold sand process, when the bentonita (clay), silica sand and coal during the metal parts production are mixed in green sand production. The raw materials were characterized through X-ray diffraction (XRD), thermal (DSC) and thermogravimetric analisys (TG). The atomized powder thermogravimetric analysis curve shows three intervals associated with the mass loss and it is typical of clay commercial application.


2018 ◽  
Vol 34 ◽  
pp. 02042 ◽  
Author(s):  
Rajeb Salem Hwidi ◽  
Tengku Nuraiti Tengku Izhar ◽  
Farah Naemah Mohd Saad

In Malaysia, limestone is essentially important for the economic growth as raw materials in the industry sector. Nevertheless, a little attention was paid to the physical, chemical, mineralogical, and morphological properties of the limestone using X-ray fluorescence (X-RF), X-ray diffraction (X-RD), Fourier transform infrared spectroscopy (FTIR), and Scanning electron microscopy / energy dispersive x-ray spectroscopy (SEM-EDS) respectively. Raw materials (limestone rocks) were collected from Bukit Keteri area, Chuping, Kangar, Perlis, Malaysia. Lab crusher and lab sieved were utilized to prepare five different size of ground limestone at (75 µm, 150 µm, 225 µm, 300, and 425 µm) respectively. It is found that the main chemical composition of bulk limestone was Calcium oxide (CaO) at 97.58 wt.% and trace amount of MnO, Al2O3, and Fe2O3 at 0.02%, 0.35%, and 0.396% respectively. XRD diffractograms showed characteristic peaks of calcite and quartz. Furthermore, main FTIR absorption bands at 1,419, 874.08 and 712.20 cm-1 indicated the presence of calcite. The micrographs showed clearly the difference of samples particle size. Furthermore, EDS peaks of Ca, O, and C elements confirmed the presence of CaCO3 in the samples.


2012 ◽  
Vol 727-728 ◽  
pp. 1422-1427
Author(s):  
Suélen Silva Figueiredo ◽  
Cibelle Guimarães Silva ◽  
Izabelle Marie Trindade Bezerra ◽  
Suellen Lisboa Dias ◽  
Gelmires Araújo Neves ◽  
...  

The construction industry in addition to being considered one of the biggest natural resources consumers is still responsible for generating large quantities of residues. The impacts caused by these residues have motivated research aimed at developing new techniques for reuse and recycling this material by using as raw material to make alternative materials. The introduction of demolition residues (DR) in soil-lime bricks replacing part of the pozzolan becomes possible due to the cementing properties that these residues may present when finely grounded. This study aims to evaluate the durability of soil-lime blocks embedded with demolition residues. For this study the raw materials were characterized by particle size distribution analysis, X-ray diffraction and chemical analysis. Then test specimens were prepared using mixes in a 1:10 ratio of lime:soil and embedded with residue in partial replacement of lime, in the proportions of 25%, 50% and 75% with curing period of 90 days. Later, the test specimens were evaluated for durability. The results showed that soil-lime bricks embedded with contents above 50% of residues had their durability affected.


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