scholarly journals Characterization of weathering profiles of the crystal rocks of eastern Bucaramanga and definition of hydrogeological properties

2017 ◽  
pp. 16-30
Author(s):  
Juan Diego Colegial-Gutiérrez ◽  
María Camila Forero-Quintero ◽  
María Alejandra Fuentes-Rueda ◽  
Sully Gomez Isidro
Keyword(s):  
Chemical Weathering ◽  
Unit Weight ◽  
X Ray ◽  
Weathered Rock ◽  
Weathering Processes ◽  
Dry Unit Weight ◽  
Physico Chemical ◽  
Hydrogeological Properties ◽  
Definition Of

In the process of improving the knowledge of the hydrogeological potential of weathered zones in crystalline rocks and compounds that can behave as aquifers, this article is performed whose area of study is located east of the metropolitan area of Bucaramanga, Santander Massif consists of two main lithological units; the Neis of Bucaramanga and Santander Group plutonic (diorite, granodiorite-tonalite gray quartz monzonite and monzogranite). These rocks have undergone brittle deformation, physico-chemical weathering mainly influenced by the tropical atmosphere of the area also are jointed and fractured creating conditions that facilitate the flow of water and in turn be optimized weathering processes in the region. He appealed to the identification and location of field weathering profiles made a detailed study of outcrops, presenting a thickness of 90.4 m for the profile of the Gneisic rock weathering and 68.5 m for the profile of granodiorite rock, made up 6 steps weathering of which samples each were taken and carry out macroscopic analysis, petrographic and geochemical using thin films, determining the percentage of porosity, humidity, dry unit weight, X-ray fluorescence, electron microscopy Sweeping and Grading; base characterizing weathering profiles and properties, highlighting the potential hydrogeological found in the Range II: Slightly weathered rock and interval V: Completely weathered rock profile of granodiorite rock and Rock Gneisic profile, the interval III : Moderately weathered rock and the range V: Completely weathered rock, since these stages of weathering, moisture peaks present, regular micro fractures and high porosities.

scholarly journals Characterization of Spent Ni-MH Batteries

2012 ◽  
Vol 730-732 ◽  
pp. 569-574
Author(s):  
Marta Cabral ◽  
Fernanda Margarido ◽  
Carlos A. Nogueira
Keyword(s):  
Quantitative Analysis ◽  
Electrode Materials ◽  
Phase Identification ◽  
Recycling Process ◽  
X Ray ◽  
Leaching Experiments ◽  
Plastic Components ◽  
Definition Of ◽  
Physical And Chemical

Spent Ni-MH batteries are not considered too dangerous for the environment, but they have a considerable economical value due to the chemical composition of electrodes which are highly concentrated in metals. The present work aimed at the physical and chemical characterisation of spent cylindrical and thin prismatic Ni-MH batteries, contributing for a better definition of the recycling process of these spent products. The electrode materials correspond to more than 50% of the batteries weight and contain essentially nickel and rare earths (RE), and other secondary elements (Co, Mn, Al). The remaining components are the steel parts from the external case and supporting grids (near 30%) containing Fe and Ni, and the plastic components (<10%). Elemental quantitative analysis showed that the electrodes are highly concentrated in metals. Phase identification by X-ray powder diffraction combined with chemical analysis and leaching experiments allowed advancing the electrode materials composition. The cathode is essentially constituted by 6% metallic Ni, 66% Ni(OH)2, 4.3% Co(OH)2 and the anode consists mainly in 62% RENi5 and 17% of substitutes and/or additives such as Co, Mn and Al.

HIGH RESOLUTION MINERALOGICAL CHARACTERIZATION OF SEDIMENTS - LAKE BOLĂTĂU-FEREDEU (ROMANIA)

2021 ◽  
Vol 16 (1) ◽  
pp. 199-210
Author(s):  
Máté Karlik ◽  
◽  
Ildikó GYOLLAI ◽  
Anna VANCSIK ◽  
Krisztián FINTOR ◽  
...  
Keyword(s):  
High Resolution ◽  
Chemical Weathering ◽  
Soil Formation ◽  
Mineralogical Characterization ◽  
X Ray ◽  
Geochemical Conditions ◽  
Formation Conditions ◽  
Physical And Chemical ◽  
Microbial Mediation

The catchment (bedrock and soil) and sediments of lake Bolătău, Romania were studied by high resolution multi-methodological investigations to characterize paleoenvironmental and formation conditions. Particle size analyses, optical and cathodoluminescence microscopy, FTIR-ATR and Raman spectroscopy, X-ray powder diffraction, and XRF were applied for microtextural, chemical, micro-mineralogical and embedded organic material characterization and distribution of the sediments, especially concerning geochemical conditions, like pH and redox potential change. Our results support physical and chemical weathering in the process of soil formation with appearance of the new minerals appear (10Å sized phyllosilicates and clay minerals). Comparison of these studies offer possible differentiation of syn- and diagenetic mineralization, the clarification of debris contribution, microbial mediation and complex mineralization via decomposition of cell and extracellular polymeric substance. Based on the analyses on the abrasives, a suboxic environment prevailed in the depositional area and considerable microbial contribution is proposed via accumulation of lake sediments.

Evaluation of Attapulgite Clay Content from Piauí in Sorption Characterization of Water in the Polyester Matrix Composites

2014 ◽  
Vol 775-776 ◽  
pp. 471-475
Author(s):  
Renata Barbosa ◽  
Tatianny Soares Alves ◽  
Celso Hartmann Júnior ◽  
Gabriel Neiva Cadah
Keyword(s):  
Drilling Fluid ◽  
Clay Content ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Pet Waste ◽  
X Ray ◽  
Physico Chemical ◽  
Polyester Matrix ◽  
Attapulgite Clay

The physico-chemical characteristics of attapulgite clay confer appropriate properties to their different industrial uses, such as: Drilling fluid, bleaching of vegetable oils, mineral and animal grease and oil absorbents, pet waste absorbents (pet litter), purification of drinking water etc. The aim of this study was the chemical modification of attapulgite originally from state of Piauí, for applications in polyester-based composites. The unmodified and modified clay were characterized by X-ray diffraction (XRD). In order to evaluate the interaction of clays with organic solvents, the test of Foster swelling with gasoline, diesel and toluene was conducted. The polyester resin-based composite and clay unmodified and modified in different percentages were molded by hand lay up technique and they were characterized by water sorption.

(U-Th-Sm)/He dating of supergene Fe duricrusts in NE French Guiana: implications of a multiproxy approach

2020 ◽  
Author(s):  
Beatrix Heller ◽  
Silvana Bressan Riffel ◽  
Cécile Gautheron ◽  
Thierry Allard ◽  
Guillaume Morin ◽  
...  
Keyword(s):  
Chemical Weathering ◽  
French Guiana ◽  
X Ray Diffraction ◽  
X Ray ◽  
Weathering Processes ◽  
Erosion Rates ◽  
Large Dispersion ◽  
Icp Ms ◽  
Physical Erosion ◽  
Geochemical Analyses

&lt;p&gt;Laterites are developing under intense chemical weathering and low physical erosion rates. Despite their large extension at the Earth&amp;#8217;s surface, there is still a lack of time constraints for their formation, evolution and relation with climatic change. Nevertheless, several chronological studies show that they represent a geological record at least all along the Cenozoic Era. Indeed, laterite samples often contain several coexisting generations of iron oxides and oxyhydroxides that indicate successive weathering processes due to the dissolution of previously formed phases followed by reprecipitation. This study focuses on the condition and chronology of weathering in Northeastern French Guiana which generated pedogenic iron crusts on Paleoproterozoic mafic and intermediate rocks. It offers the opportunity to document the evolution of this part of the Guyana Shield, known as a tectonically stable area since the Cretaceous. The two sampling sites, Kaw and Baduel, are paleosurfaces at 300m and 100m elevations, respectively, that have been dated previously by paleomagnetism, providing Eocene ages for both sites, albeit with some substantial uncertainties and dispersion [1].&lt;/p&gt;&lt;p&gt;Since the duricrust (top layer) of the lateritic profile is enriched in hematite and goethite, we aim to date those mineral phases using the (U-Th-Sm)/He method. Older ages are from Oligocene and Miocene epochs for the Kaw and Baduel sites, respectively, with a large dispersion in the age values, as expected from the presence of several generations of Fe-minerals. Identification of petrological relationship between these different generations is hindered by their intimate mixing. In order to overcome this difficulty and to identify the episodes of weathering and mineral precipitation, we coupled a number of mineralogical and geochemical analyses, namely through powder and single grain X-ray diffraction, energy dispersive X-ray spectrometry (SEM-EDS) and solution- and LA-ICP-MS. Data on formation ages of secondary iron phases will be discussed by reference to literature, in terms of geodynamic and paleoclimatic forcing.&lt;/p&gt;&lt;p&gt;[1] Th&amp;#233;veniaut, H., and Freyssinet, P. (2002): Timing of lateritization on the Guiana Shield: synthesis of paleomagnetic results from French Guiana and Suriname. Palaeogeography, Palaeoclimatology, Palaeoecology (178) 91-117&lt;/p&gt;

Physico-Chemical Characterization of Some 5,5-Disubstituted-1,3-Dixanthyl Barbituric Acids

1967 ◽  
Vol 21 (4) ◽  
pp. 225-231 ◽  
Author(s):  
B. C. Flann ◽  
J. A. R. Cloutier
Keyword(s):  
Experimental Data ◽  
Powder Diffraction ◽  
Infrared Spectra ◽  
Chemical Characterization ◽  
Melting Points ◽  
X Ray ◽  
Physico Chemical ◽  
Diffraction Patterns ◽  
Derivatives Of

The dixanthyl derivatives of 21 clinically important barbituric acids have been prepared. Melting points, infrared spectra, and x-ray powder-diffraction patterns of the purified compounds are presented. Infrared evidence is used to discuss the position of the linkage between the xanthyl and barbiturate portions of the derivatives. The experimental data should prove of particular value for the microchemical identification of barbiturates.

scholarly journals Synthesis and Physico-Chemical Characterization of a New Non-Centrosymmetric Organic Cation Iodate

2011 ◽  
Vol 7 (2) ◽  
pp. 1315-1323 ◽  
Author(s):  
A.C. Dhiab ◽  
W. Smirani Sta ◽  
M. Rzaigui
Keyword(s):  
Organic Cation ◽  
Three Dimensional ◽  
Chemical Characterization ◽  
Halogen Bonds ◽  
Monoclinic System ◽  
X Ray ◽  
Dimensional Network ◽  
Physico Chemical ◽  
Graph Set

The synthesis, crystal structure and physico-chemical characterization are presented for the piperazinium bis iodate dihydrate. An X-ray investigation has shown that this compound crystallizes in a non-centrosymmetric monoclinic system, space group Pc with the lattice parameters: a = 8.969 (2) Å, b = 6.027 (3)  Å, c = 11.958 (2)  Å; V = 612.7 (3)  Å3 and Z = 2. The structure was solved from 3546 independent reflexions with R1 = 0.053 and wR2 = 0.130. I…O halogen bonds [R22(4) graph-set motif] range between 2.770 (4) and 3.108 (1) Å and connect neighboring IO-3 anions with each other so as to create a bi-dimensional layer parallel to the (b,c) plane. These layers are interconnected via N−H…O and C−H…O, to the piperazinium dication to generate a three-dimensional network.

scholarly journals Characterization of carbon fibrous material from platanus achenes as platinum catalysts support

10.30544/588 ◽  
2020 ◽  
Vol 26 (4) ◽  
pp. 375-383
Author(s):  
Branka V. Kaludjerovic ◽  
Vladislava M. Jovanovic ◽  
Sanja I Stevanovic ◽  
Zarko D. Bogdanov ◽  
Sanja S. Krstic ◽  
...  
Keyword(s):  
Carbon Materials ◽  
Platinum Catalysts ◽  
Nitrogen Adsorption ◽  
Carbon Support ◽  
X Ray Diffraction ◽  
X Ray ◽  
Physico Chemical ◽  
Substrate Properties ◽  
Adsorption Desorption

Carbon materials with developed porosity are usually used as supports for platinum catalysts. Physico-chemical characteristics of the support influence the properties of platinum deposited and its catalytic activity. In our studies, we deposited platinum on carbon fibrous like materials obtained from platanus seeds - achenes. The precursor was chemically activated with different reagents: NaOH, pyrogallol, and H2O2, before the carbonization process. Platinum was deposited on all substrates to study the influence of the substrate properties on the activity of the catalyst. Carbon materials were characterized by nitrogen adsorption/desorption isotherms measurements, X-ray diffraction, and scanning electron microscopy. It was noticed that the adsorption characteristics of carbon support affected the structure of platinum deposits and thus their activity.

Enclosing the functional properties of pyrazolato-based coordination polymers within a structural frame: the role of laboratory X-ray powder diffraction

2013 ◽  
Vol 28 (S2) ◽  
pp. S106-S125 ◽  
Author(s):  
Simona Galli ◽  
Norberto Masciocchi
Keyword(s):  
Functional Properties ◽  
Powder Diffraction ◽  
Coordination Polymers ◽  
Laboratory Data ◽  
Recent Experience ◽  
Structural Description ◽  
X Ray ◽  
Physico Chemical ◽  
Metal Bonds

Ab initio X-ray powder diffraction structural analyses from laboratory data have been widely employed in the characterization of coordination polymers not affording single crystals of suitable quality to undergo conventional structural determinations. This is particularly true for coordination polymers built upon strong ligand-to-metal bonds, as those formed by anionic, nitrogen-based heterocycles - pyrazolates, imidazolates, pyrimidinolates and more complex moieties derived therefrom. More than one hundred species belonging to this class have been structurally characterized in the last three decades, affording key, otherwise inaccessible stereochemical and supramolecolar features. This contribution summarizes our most recent experience in the XRPD structural characterization of pyrazolato-based coordination polymers, devoting a special consideration to the methodologies and tricks which allowed us to juxtapose the structural description of these materials to their physico-chemical and, above all, functional properties.

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