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The Mesa de Los Santos region is known for its continuous development in infrastructure, agriculture, and tourism, especially in the north sector, which has generated a greater demand in the supply of drinking water. Previous geological, hydrological, and geophysical studies highlighted the importance of understanding the physical properties of rocks, as well as their spatial estimation, the reason why we implemented neural network models in this work. The laboratory results for the samples associated with the Los Santos Formation present porosities of up to 25%, %, while the Rosa Blanca Formation shows values of less than 5% in carbonate units and up to 30% for sandy lithologies. The P-wave velocity for both formations of interest is in a range between 1000 y 6000 m · s-1. The resistivity values were influenced by the pore fluid (water), obtaining values between 10² - 104 Ω · m for the Los Santos and Rosa Blanca formations. The maps generated by the neural network provided a consistent and accurate geological distribution compared to traditional interpolation methods. However, uncertainty was noted in areas with intense fracturing and weathering, which could affect the results in areas close to geological faults. These findings provide valuable information for geological, hydrogeological, and engineering studies in the region. [ABSTRACT FROM AUTHOR]

The geological modeling commonly performed on mineral deposits is of the deterministic type, but it has been demonstrated that probabilistic modeling is more adequate to know or quantitatively measure the associated uncertainty. This study is aim to quantify the uncertainty of weathering crustal horizons for a sector of the San Felipe nickel deposit, based on its probabilistic modeling. The descriptive geological model of the lateritic deposit was taken as a basis, characterized by the lithological zoning at depth. The probabilistic Sequential Indicator Simulation with Locally variable Proportions was used, through which 50 equiprobable scenarios of the geological units are synthetically reproduced, conditioned to 3,884 composites from the network of 100 m x 100 m drillholes. As a result, the 3D model of the lithological horizons on block support is presented for the study sector, as well as the entropy maps that quantify the uncertainty associated with the model of the modeled geological units. As conclusion, we can say that, due to the variability present in this type of lateritic deposit, the availability of geological information is still insufficient to reproduce the model of weathering crust horizons with an adequate level of certainty. [ABSTRACT FROM AUTHOR]

This paper presents the results of the study of the influence of concrete curing in compressive strength in warm-rainy climate. Concrete several specimens were emptied in the laboratory, there were curing by three methods and tested for resistance at the ages of 3,7, 14, 28, 56 and 91 days. Compressive strength in weathering is shown to be associated with environmental factors such as precipitation and temperature. [ABSTRACT FROM AUTHOR]

Copyright of APUNTES - Journal of Cultural Heritage Studies is the property of Pontificia Universidad Javeriana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Además de is the property of Ademas de: Revista on line de artes decorativas y diseno and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Tecnología y Ciencias del Agua is the property of Instituto Mexicano de Tecnologia del Agua (IMTA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Working scales used to date have not allowed studying the faults and fractures of the weathering crust of the San Felipe deposit in details. The aim of this research is to characterize those structures that have conditioned developing and conserving crust from the mineral deposit. As a result of the structural interpretation from measurements of geological contacts in boreholes, the presence of fracture zones called San Felipe Faults System was identified. These structures cut and displace the horizons, giving the deposit its current geometry, characterized by a lateritic crust with sinusoidal appearance caused by fault planes displacements through linear structures with predominant direction of 315 ° -345 °. It was concluded that these results will be useful for identifying discontinuities, fracture plans, probable direction of crust horizon displacements and its resources, as well as the slides in mining fronts. [ABSTRACT FROM AUTHOR]

Most of the world livestock breeding is dependent on the seasonality of production of fodder. Thus, it is necessary to ensure the availability of forage resource and the alternative can be achieved through conservation. To ensure efficient conservation stages of the conservation process, from cutting to the storage, must be well understood. The plant respiration after cutting, the type and size of equipment, facilities for the storage and the weather during the process influence the quality of that food. Comparing the two cases, the hay is the most time consuming because the material needs to be dried to achieve a humidity around 20% and silage process the material is harvested with a moisture content between 50-65%. Objectively with this revision discuss the factors that influence the loss of forage quality during storage in the form of hay and silage, addressing the losses caused by respiration of plants, damage caused by rain, losses caused by agricultural implements and losses during storage. [ABSTRACT FROM AUTHOR]

Copyright of Boletin de Geologia is the property of Universidad Industrial de Santander and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Gestión y Ambiente is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

San Felipe is a distinctive residual deposit of crust weathering due to its high silica content. Determining the weathering indexes and the coefficients of geochemical mobility in the weathering crust was the aim of this work. The accumulation and extraction of the main components (SiO2, MgO, FeO, Fe2O3, and Al2O3) was calculated by using the weathering coefficients of Ginsburg (1946) and Rudnik (1966). The weathering indexes analysis and the extraction--accumulation degree allowed to evaluate the mobility, concentration, and distribution of the elements and clarifying the mechanism of migration and evacuating of nickel. The mass balance showed how the reduction of the most movable components (magnesium, silica) and the increase of the cumulative (iron, aluminum) occurs, showing that the silica content exceeds the attributable values to a process of weathering. [ABSTRACT FROM AUTHOR]

This article exposes the resolving power of the magnetic susceptibility measurements in basement minerals samples of the lateritic weathering profile as an element of complementary analysis in the petrographic characterization of the rocks, and useful in the mapping of the magnetic heterogeneities of the basement. The comparison of the magnetic susceptibility data with the petrographic data of different samples revealed that even in samples that correspond to homogeneous lithotypes, great heterogeneities and differences can be manifested from the physicalmineralogical point of view. In general, a high concordance was observed between the intensity of the weathering processes in the rock samples, and the values of the magnetic susceptibility of such samples. The results support the possibility of extrapolating the composition information to samples with magnetic susceptibility measurements and without petrographic studies. [ABSTRACT FROM AUTHOR]

The quantification of the mineral resources in the iron-weathering crusts is affected, among other factors, by the great variability in their thickness, which requires the use of very dense drilling nets that are very expensive. This work presents results of the application of the geophysical method of induced electric polarization induced vertical (SEV-PI) in the Cuban ophiolites where iron-cobaltiferous weathering crusts are developed, in order to determine their thicknesses and contribute to the increase of the precision in the calculation of resources. The results show that the method has good resolution power to estimate the thickness of the lateritic crust and to map the irregularities of the laterites-basement contact. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Reports and scientific publications about the ferronickel ore bodies located to the northeast of the western region of Cuba indicate the presence of a lateritic crust developed by weathering processes occurring in ultramaphic serpentinized rocks. However, the geological investigations of the ophiolitic massif of Moa-Baracoa have revealed the presence of different sequences or lithological groups while more recent exploration projects have allowed a better characterization of the weathering crust of several ore bodies of the region based on the petrological, mineralogical and geochemical results. In view of these results, this article presents the description of several types of weathering crust profiles that are common in the area to subsequently characterize each profile from the mineralogical phases that make up the profile horizon and the content of deleterious and useful materials. Four types of lateritic crust profiles have been therefore identified; which are as follows: 1) Weathering profile over mantelic rocks; 2) Weathering profile over oceanic rocks; 3) Weathering profile over rocks of the mantle-oceanic crust transition area and 4) Mixed and Complex weathering profile. [ABSTRACT FROM AUTHOR]

This article proposes the implementation of bioengineering techniques to provide economical and effective solutions to the environmental effects caused by the tailings ponds that are exposed to weathering agents. The plantation of tree species as Casuarina equisetifolia, Vetiveria zizanioide, Cynodon dactylon, Panicum maximum and Digitaria decumbens stent which are highly available and adaptable to existing conditions was tested in order to build up a vegetal cover that prevents the erosion of the pond slopes. The results were: 90 % of the species survived and over 95 % stability in the control over the erosion of the soil surface. [ABSTRACT FROM AUTHOR]

Weathering processes of geologic materials and the inputs of dry and humid atmospheric depositions yield the chemical composition of runoff at the watershed. When the ocean component is dominant, the inputs of Na+ can produce pH reduction in runoff water. The sodium dominance index (IDS) was determined as an estimation of weathering rate and resistance to acid deposition on Cuyaguateje, San Juan y Martínez and Mantua watersheds. The results show that linear regressions of IDS with pH are not significant in Cuyaguateje watershed, but they are significant in Mantua and San Juan y Martínez watersheds. These results are evidence of acidification processes originated by atmospheric inputs of marine salts. The IDS value for all studied watersheds has good correlation with annual flow of bicarbonates. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Investigación is the property of Universidad Pedagogica Experimental Libertador and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The results of the analyses performed on the decorative cornice limestone of building 5N2 in group A at Río Bec are presented, with the finality of determining the causes, mechanisms and effects that weathering promotes. These processes haven't been well studied for the southeast of Campeche, the region in which the archeological zone of Río Bec is located. Knowledge of these mechanisms is necessary for the subsequent conservation of the prehispanic buildings of the region. The stones of the cornice presented different conservation states; therefore, samples were taken from each of the disintegration states identified in field. These samples were studied in thin section, and by scanning electron microscopy and X ray diffraction. The results show many weathering features due to chemical processes; among the most notorious is the transformation of micrite to acicular crystals. These effects are similar to those that take place in edaphologic contexts that present calcium carbonates associated with water, decaying organic matter, fungus and roots. The composition of the rocks in conjunction with the archeological context and other environmental factors determined the different states of disaggregation found in the limestone of the cornice. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales is the property of Academia Colombiana de Ciencias Exactas, Fisicas y Naturales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this scientific note I analyze two new paradigms in the Cactaceae recruitment and establishment. The first one is related to the facilitation effect given by "nurse objects" (rocks) compared with "nurse plants", which could be enhanced in places where fog deposition and dew formation are highly frequent phenomena. The trophic biology of the rock-colonizing cactus is the second paradigm. Recent studies have discovered and isolated bacteria living into (endophytic) and outside (in the rhizoplane) cactus roots which are responsible for rock weathering and nutrients release. Research on the "hidden" water gains driven by rocks and bacteria isolation and inoculation to cactus seedlings are very important topics in the endemic cactus populations' restoration and recovering plans in arid environments of the Andean western slopes. [ABSTRACT FROM AUTHOR]

This work characterizes the materials of the polichromed stone sculpture "The Virgin of Snows", which was exposed to the elements from principles of the XX century and up to the 2004, in the town of Luyanó, City of Havana and is nowaday exposed in the room museum of the University School of San Geronimo of Havana located in the Historical Center of Havana. The study was carried out with reason of the restoration of the piece. The vestiges of pigments were characterized by Portable X-ray Fluorescence and microchemical test, the stratigraphic analysis by Optic Microscopy, the mineral of the original rock by X-ray Diffraction and Atomic Absorption Spectrometry. The porosity and the stability of the mineral were determined by Small Angles X-ray Scattering Dispersion (SAXS) and Potentiometry, respectively. Pigments were identified: blue-green pigment based on copper and blue pigment based on silicates; the white pigments: zinc white and lithopone; the golden colour in pupurin, the silver colour based on aluminium paint and the use of earth pigments in the colors: black, pink and clear (soft) ochre. The rock was identified as calcite. The transformation of the particles toward a laminate transitive form and the increase of big pores in the exfoliation of the sculpture, corresponds with a highly degraded mineral. [ABSTRACT FROM AUTHOR]

Physical, mechanical and aesthetic properties were evaluated on structural boards as plywood and oriented strand board (OSB). The boards were covered by two commercial superficial protectors for wood that do not form films, and were maintained outside with no other protection during one year, in test field, according to the ASTM norm D1006:1973. Loss of mechanical properties was statistically determined and the influence of exposure time on the physical and aesthetic properties were evaluated. The main conclusions were that the protection of the used coverings was not effective and the main hypothesis that the non-forming film protect the surface and that typical defects of cracking, erosion and discoloration do not appear, was not proved. It was not observed qualitative differences between both protectors, so the higher price of one of them is not justified. [ABSTRACT FROM AUTHOR]

The mining plant's wastes discharged in tailings ponds are under certain environmental conditions which cause chemical alteration, dispersion and mobility and therefore leading to a secondary mineralogy from the first one. In the district Zimapan, the orebody (skarn) containing Zn-Pb-Ag-(Cu) has generated a considerable amount of waste (50 years of disposal) stored in the ponds of San Miguel, Santa Maria and El Monte. The objective of this investigation was to determine the mineralogical neo-formation for the identification of the chemical behavior of metals in addition to environmental and health impact. An induction-coupled plasma spectrometry conducted revealed significant concentrations of trace elements in the chemical composition of the waste. The average concentrations were 13 135 mg/kg for As, 3 934 mg/kg for Pb, 11 363 mg/kg for mg/kg for Zn and 610 mg/kg for Cd. According to the mineralogical characterization using X-ray diffraction, calcite and quartz were identified as the majority mineral phases and gypsum, pyrite and sphalerite as the minority mineral phases as well as traces. During the completion of optical microscopy of polarization, sweeping electronics and electronic microsound, the neoformation of arseniates ferric (scorodite and symplesite), hydroxides and ferric sulfates and anglesite and cerusite was identified resulting from alteration, oxidation, sulphide hydrolysis such as arsenopyrite, pyrrhotite and galena. The sphalerite was classified as marmatite because of its iron content. As, Cd and Bi were found in particles of sulphosalts (boulangerite mineral); which can be released during meteorization; consequently, it was concluded that the waste is considered to be potentially toxic. [ABSTRACT FROM AUTHOR]

It is well-known that the geographical situation of the station of natural assays of Cojímar, located in the City of Havana in Cuba, and the variation of their environmental conditions with the time, produce an important influence in the behavior of many metals, especially aluminum anodized and lacquered systems. The present study had the purpose of evaluating the resistance capacity of different variants of structures of anodized and lacquered aluminum of different origins, under the conditions of natural assays. The samples, obtained through different anodized and lacquered technologies, were exposed at the coastal marine atmosphere of the assay station of Cojímar, located on the North coast of Havana City. The samples were carefully observed visually and with a small amplification, after several months of exhibition and the thickness of their anodized and lacquered coat were measured before and after the assays. The gloss of the surfaces was also determined before and after the rehearsal. Bigger affectations were observed in lacquered samples. The importance of the thickness of the protective layer and their impermeabilization grade in the protection capacity of the applied protection system on the aluminum was established, as well as the grade of powder retention of the samples during the experiment. Among the lacquered samples, those of darker tones exhibit greater resistance and the anodized samples experience smaller loss of thickness during the assays. A correspondence between the loss of gloss and the visual observation of the samples was observed. [ABSTRACT FROM AUTHOR]

Copyright of Agro Sur is the property of Universidad Austral de Chile, Facultad de Ciencias Agrarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The concrete behavior in service depends on the atmospheric conditions where it is exposed. The determination of the atmosphere effect in stability of a given material depends on several factors related with time of wetness and atmospheric pollution. In Colombia, a few studies about this subject had been performed. In this study, cylindrical specimens of mortars, reinforced and non-reinforced, were exposed in Medellin, Bogota and Barranquilla. In order to establish the deterioration degree of mortars, after exposure, electrochemical and carbonation tests were carried out to the reinforced and non-reinforced specimens, respectively. [ABSTRACT FROM AUTHOR]

The weathering crust developed on serpentine ultrabasic rocks in the region of Moa have been broadly characterized from the geochemical and mineralogical point of view, not being this way regarding their behavior geologic engineer, which constitutes a fundamental element to undertake any evaluation of risks associated to landslide. The present investigation embraced the residual crust on which the geomechanic methods were applied traditionally used to characterize the behavior geologic engineer of a rocks. It was carried out the visual description of the different lateritic horizons, and indexes related with the physcal, mechanical, structural and textural properties such as the microfracture and micropetrographic, rock quality designation of rock (RQD) and unified alteration index were applied. As a result a proposal is made of engineering geological classification of the weathering profile in function of the weathering grade, the which it was defined in a scale from I to V starting from the typical values of the properties physical and mechanical, RQD, relationship percentage rock/soil and other two elements related to the way of breakage of slope and the typology of most common sliding for each weathering grade. [ABSTRACT FROM AUTHOR]

In this article the obtained results of the application of descriptive and multivariate statistical methods are presented during the interpretation of airborne spectrometric (eU, eTh y K) and aeromagnetic (ΔT), belonging to the complex airborne geophysical survey of the northeastern region of Cuba. With the help of the statistical treatment of the airborne geophysical data, charts of variations of the eU, eTh and K contents were made, as well as of their relationships and ΔT, in each one of the formations and levels of the ophiolitic association in the Mayarí and Sagua-Moa sectors. Starting from the interpretation of the results it is known that the most radioactive rocks are located in the Sagua- Moa sectors, evidencing bigger alteration grade, clay content and content of organic matter of the floors and rocks developed in this sector with regard to those of Mayarí. With the Analysis of Factors the lateral variations of the mentioned characteristics are shown and of the thickness of the lateritic crusts. Areas of redeposited lateritic crusts and of prevalences in surface and depth of volcanic and serpentinized material are also defined. [ABSTRACT FROM AUTHOR]

The extensive crust of waste with the main Fe-Ni-Co ore deposits in Eastern Cuba overlies a significant portion (30 % of total surface) of the ophiolite of the Sierra de Nipe-Cristal and Moa-Baracoa ranges. During prospecting works of these ore deposits were found the different intrusive ophiolitic complexes and levels with a diversity of mafic and ultramafic rocks having different trends of the weathering process with more or less loss or retention of mineralizing (Ni,Co) and contaminant (SiO2, Al2O3, MgO) components meanly for mafic varieties which decrease Ni and increase significantly the content of free SiO2 and other nocive to the metallurgical process minerals like meanly gibbsite, halloysite, caolinite, beydellite, montmorrillonite, so becoming an important aspect their identification, study and cartography by both geologists and miners as far as an important part of mining workings goes towards areas related with higher levels of ophiolites where are more frequently mafic and transitional within mafic and ultramafic rocks which generally produce Ni- mineralized crusts of waste, but with high content of contaminants. [ABSTRACT FROM AUTHOR]

Mineral deposit descriptive models are valuable geological information network usefull to explore and assessment the territories with these atributes in their geologic pattern and makes them perspectives for the discovery of new mineral resources. In this paper a generalized approach is given about weathering as main process in the formation of laterites as well as three proposal of Fe-Ni-Co laterite descriptive models developed on Mayarí-Baracoa Ophiolitic Belt located in Eastern Cuba. [ABSTRACT FROM AUTHOR]

The lateritic weathering crusts of the northeast of Cuba constitute sources of obtaining Ni. The relationship of this metal with the mineral phases of iron (goethite specifically) in the oxidized ores of the nickeliferous crusts has been revealed by diverse investigations ground in chemical and mineralogical analyses. In this paper they are conjugated, for profiles of different maturity degree, chemical, mineralogical and physical aspects at the level of profile, horizons and grain-sized class. The results showed a natural tendency of concentration of the different mineral phases towards certain grain-sized class. In the Moa deposit, as much in mature profiles as immature, goethite is concentrated in the grain- sized class smaller than 0,045 mm, which represents around 50 % in weight of the ochreous horizons for both types of profile, and contains 1,4 % of Ni. [ABSTRACT FROM AUTHOR]

An analysis of the figures obtained of the volume of ore brought from the weathering crust deposit of Moa, during a period of 5 years, showed a great difference between values obtained from topographical calculations and that reported for the processing plant. This prompted a revision of method used in the calculation of volume by them. A new methodology is proposed that include: registration of the initial information, determination of the errors that affect the calculation of volume, application of the universal stadia survey and the application of terrain digital model. With the use of this methodology, the total errors in the calculation of volume was reduced to 28%. The difference of tonnage between mineral dug out and the one supplied was reduced to a value of 80%. [ABSTRACT FROM AUTHOR]

This work evaluated the effect of an "oxo" additive on the physicochemical behavior of PP at different times of accelerated thermodegradation (60°C) and natural weathering. Extruded films with thickness of 60±5 μm, mixed with 0; 1,5; and 3,0 % of "oxo" additive were prepared and characterized by FTIR, DSC, TGA, NMR and tensile tests. A decrease of the molecular weight to values in the order of 10³ g/mol caused by chain scission and appearance of alcohol, carbonyl groups and double bonds were observed, as well as a decrease in melting temperatures (10-18ºC) and crystallization temperatures (≈30ºC) and changes in the multiple melting endotherm that was observed by thermal fractionation (SSA). Tensile tests showed a fragile behavior after 5 days in the oven for a content of "oxo" additive of 3,0%. The samples subjected to environmental conditions showed similar results with lower oxidation rates than those subjected to thermodegradation. [ABSTRACT FROM AUTHOR]