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Egyptian Eastern Desert is rich in many areas that contain granites masses throughout the geological era; some of them show good characteristics of the rock hardness, durability, density and mineralogy. This current research aims to utilize three main types of granite aggregates based on their mineralogical composition and Alkali reactivity with cement during concrete production. The studied granite aggregate can be also classified into red younger granite aggregate, white older granite aggregate and grey older granite aggregate. Evaluating these granite rocks as aggregate used in concrete mixture is interesting by produced three mixes using the three studied granite aggregate symbolized (Red GA), (White GA) and (Grey GA), tested mechanically to give a more detailed for the obtained results to be not restricted for only studied granite aggregate criteria but also to follow the actual reaction of this studied granite aggregate with cement. It was obtained that all studied granite aggregates within acceptable limits of concrete aggregate by following Egyptian code (ECP-203) although their variation on its mineralogical composition. Some reflections produced from change in mineralogical composition between the three studied granite aggregates exhibited by relative regression in the average physico-mechanical values for both (White and Grey GA) than (Red GA). On the other hand, slight reactive for (Red GA) than others at the age of 28 day. In addition, all produced (Red GA), (White GA) and (Grey GA) mixes were acceptable mechanically with limits of (ECP-203) giving benefit for using all of the studied granite aggregate after their detailed study involving its mineralogical composition and alkali aggregate reactivity (AAR). [ABSTRACT FROM AUTHOR]

Sediments from the ST5 deep-sea bottom core collected from the south-east Aegean Sea between Symi and Tilos islands, Greece, were examined by quantitative mineralogical analysis and geochemical analysis to infer provenance and palaeoenvironmental control over sediment deposition. The mineralogical composition comprises carbonates (mainly calcite and Mg-calcite), quartz, feldspars, serpentine, amphibole and clay minerals. Chlorite is the most abundant clay mineral, whereas smectite and illite are less abundant than in the sediments in the south-west Aegean and the Cretan Sea. Semi-quantitative analysis of clay minerals from oriented clay fractions overestimates significantly the smectite content and underestimates the abundances of illite, chlorite and kaolinite. The studied sediments are enriched in MgO, Ni and Cr, which decrease in abundance with decreasing depth, following the distribution of serpentine. By contrast, the abundances of SiO2, Al2O3, Fe2O3, Na2O and K2O increase upcore. The regional S1 sapropel horizon is enriched in V and Co and has considerably greater Ba/Al ratios than the remaining sequence. The mineralogical and geochemical relationships indicate a strong ultrabasic influence, probably from the Marmaris ophiolite in the Lycian nappes. The clay mineral distribution suggests that the smectite was mainly of volcanogenic origin, the illite was supplied by the nearby landmasses of west Anatolia and the islands of Rhodes, Tilos and Symi and the contribution from the south-east Mediterranean was limited or totally lacking. The combined use of the mineralogical and geochemical analysis of bulk sediments rather than the clay fractions is not only extremely useful in tracing sediment provenance in relatively closed basins, but it also enables a more realistic assessment of the importance of water circulation patterns on sedimentation processes in such environments. [ABSTRACT FROM AUTHOR]

Saline mineral dust particles, emitted from saline topsoil in arid and semiarid regions, contribute significantly to tropospheric aerosol particles. However, hygroscopic properties of saline mineral dust particles, especially for those found in regions other than North America, are poorly understood. In this work we investigated hygroscopic properties of 13 saline mineral dust samples collected from different locations via measuring sample mass change at different relative humidity (RH; up to 90%), and measured their chemical and mineralogical compositions using ion chromatography and X‐ray diffraction. The mass growth factors at 90% RH, defined as the sample mass at 90% RH relative to that at <1% RH, were found to display large geographical variations, spanning from ~1.02 to 6.7, and the corresponding single hygroscopicity parameters (κ) were derived to be in the range of <0.01 to >1.0. The saline components (mainly Na+, Cl−, and SO42−) contained by saline mineral dust particles largely determined their hygroscopicity, and the predicted mass growth factors at 90% RH using an aerosol thermodynamic model (ISORROPIA‐II), agreed with measured values within 20% for most of samples examined, although larger discrepancies also occurred for three samples. Our results improve our understanding in hygroscopicity of saline mineral dust particles and thus their heterogeneous chemistry and ability to serve as cloud condensation nuclei to form cloud droplets. Key Points: Water‐soluble ions showed substantial difference for saline mineral dust samples collected in different regions in ChinaLarge variation in hygroscopicity of saline mineral dust was found, largely depending on their chemical compositionMeasured hygroscopic growth factors agreed reasonably well with those predicted using ISORROPIA‐II for saline mineral dust [ABSTRACT FROM AUTHOR]

Granitoid is an important part of the upper continental crust, and therefore its thermal conductivity (TC) plays an important role in understanding the lithospheric thermal structure in a region and for geotechnical or geoengineering purposes. In above context, due to the lack of TC data or absence of proper sample for its measurements, TC values are assumed which can lead to erroneous results. In such scenario, when direct measurements are not possible, TC can be estimated by indirect methods with proper precautions. An attempt is made here to arrive at the best mixing model for granitic rocks by using TC of the individual minerals and compare the deviation between the measured and calculated values. The considered mean models are: arithmetic, geometric, harmonic, effective, Voigt-Reuss-Hill and Hashin-Shtrikman along with its lower and upper bound. Studied rocks are potassic granitoid (PG), biotite granitoid (BG), sodic granitoid (GG) and gneisses (BnG) from the Bundelkhand craton, central India. Measurements of TC are done in the laboratory on 21 samples using steady-state method. Data show wide variations in TC values for granitoids (PG: 2.7 − 3.2, BG: 2.6 − 2.9, GG: 2.9 − 3.0 Wm −1  K −1 ) and gneisses (2.9 − 3.7 Wm −1  K −1 ). Modal mineralogy of the rocks are determined using petrological and geochemical data through modal analysis and normative (CIPW-NORM) methods. The calculated TC arrived by both the methods provide a satisfactory agreement for the harmonic mean model, showing deviation from −10.9 to 17.6% for modal analysis and −16.1 to 11.5% for NORM method. Deviations from the above methods decrease further (−23.3 to 2.8% and −27.7 to −3.1%, respectively) using minimum mineral TC. Therefore, we suggest that, in the case of non-availability of the proper sample for direct measurement, the TC of very low porous granitoids could be satisfactorily determined by assessing their modal mineralogy and considering the harmonic mean model. [ABSTRACT FROM AUTHOR]

Mineral dust aerosols, produced by wind erosion in arid regions and semi-arid surfaces, are important components of the atmosphere that affect the Earth radiative budget, atmospheric chemistry and biogeochemical cycles. Dust aerosol particles are composed of a complex mixture of various minerals, mainly clays, calcite, quartz, feldspars and iron oxides. The nature and the relative abundance of the minerals are key parameters to evaluate mineral dust environmental impacts. Strong limitations remain to quantify the mineralogical composition of dust particles, mainly due to the low mass of in-situ collected dust particle samples. In this study, an analytical method and X-Ray Diffraction (XRD) measurements are presented to quantify the mineralogical composition of low mass aerosol particle samples. The method is applied on reference minerals (illite, kaolinite and palygorskite) commonly present in desert dust aerosols, as well as on lab-generated dust aerosols from desert soils. XRD measurements of theses samples in rotation in a glass capillary are combined with the Rietveld refinement method. The results obtained are repeatable and confronted to theoretical values given in the literature for the reference minerals. This method allows us to quantify the mineralogical composition of low mass dust mineral samples with an unprecedented accuracy. [ABSTRACT FROM AUTHOR]

Development of alkali-activated binder (AAB) is fast becoming a viable alternative to ordinary portland cement (OPC). However, key engineering properties of such a binder depend strongly on the chemical composition and fineness of the source materials in addition to the concentration of alkaline activators. In order to improve the reaction kinetics and subsequently, the mechanical strength of alkali activated concrete (AAC), nano-SiO 2 was proposed as a partial replacement to natural pozzolan (NP) in this study. As the composition of alkaline activators also plays a vital role on the properties of AAC, trial mixtures were prepared with varying sodium silicate to sodium hydroxide (SS/SH) ratio. Subsequently, NP was partially replaced with nano-SiO 2 in the selected mix to enhance the properties further. Fresh properties, such as, setting time of alkali-activated pastes (AAP) and the workability in terms of flow of mortar were determined. Evolution of compressive strength of concrete cured at 60 °C was monitored. Scanning electron microscopy (SEM) and X-ray diffration (XRD) were utilized to determine the morphology and mineralogy of the AAP, respectively. In addition, FTIR was used to identify functional groups formed in the AAP. The study reveals that a SS/SH ratio of 2.5 was suitable in achieving superior strength. AAC prepared using NP and nano-SiO 2 exhibited improved strength and microstructural characteristics. However, 5% nano-SiO 2 showed significant enhancement in the compressive strength and microstructural characteristics as compared to those prepared with other replacement levels. Consequently, the results of this study provides important information on developing NP-based sustainable building material with remarkable enhancement in the properties by adding nano-SiO 2 . [ABSTRACT FROM AUTHOR]

Mineralogical composition has a great influence on the mechanical behavior and the micro-cracking process of crystalline rocks for CO 2 and natural gas storage. This study numerically investigates the influence of mineralogical composition (i.e., quartz content) of a dominantly felsic phaneritic igneous rock with respect to rock strength and the associated micro-cracking behavior using a grain-based modeling approach in two-dimensional Particle Flow Code (PFC2D). First, numerical specimen models with different mineralogical compositions are generated. The generated numerical models have the same geometry of the assembled grain structure to minimize the effect of grain scale heterogeneity on the simulation results. Micro-parameters previously calibrated to match the macro-properties of the Bukit Timah granite are then assigned to the numerical models. In the numerical simulation of uniaxial compression tests, the strength and Young's modulus are found to increase with the increase of quartz content in the numerical model, while the Poisson's ratio and the maximum volumetric strain gradually decrease. The simulated strength behavior is in good agreement with the laboratory test results obtained from previous studies. However, the crack damage stress seems not to be affected by the quartz content. The total number of generated micro-cracks is also found to gradually increase as the quartz content in the numerical model increases. The rock strength shows a good correlation with the total number of generated micro-cracks. Two mechanisms are identified to initiate the nearly vertical macroscopic fractures which are generated in tension. At last, the influence of spatial distribution of mineral grains on the simulated strength property and micro-cracking behavior is discussed. [ABSTRACT FROM AUTHOR]

Variations in mineralogical and elemental composition of Turbic Cryosol (King George Island and James Ross Island), Skeletic Cryosol (J. Ross Island, the Trinity Peninsula), Leptic Andosols (Deception Island), and Skeletic Andosols (Deception Island) were studied. Significant differences in mineralogical composition in size fraction, vertical and horizontal position were determined by X-ray diffraction quantitative analysis. The differences were attributed to a variable degree of chemical weathering process. As a product of weathering were defined montmorillonite, chlorite, microcrystalline polymorphous silica, Fe oxides, and oxyhydroxides. Their content was increased towards the surface and in a finer fraction. Crystal thickness and size distribution of montmorillonite was measured by the Bertaut-Warren-Averbach technique and the results confirmed higher intensity of chemical weathering in Turbic Cryosols (J. Ross Island and King George Island). Feldspars and volcanic glass were the main phases found in soil samples from Deception Island. They were determined as phases of parent rock and indicated low intensity of chemical weathering. Clinoptilolite was identified in soil samples from J. Ross Island and Deception Islad and its hydrothermal origin was supposed. Soil (sample AP) from Base General Bernardo O'Higgins Riquelme had significantly higher content of phosphate minerals, which was a result of ornithogenic activities. Macro elements content was consistent with mineralogical analyses. Turbic Cryosols were rich in iron, aluminium, magnesium, and manganese (> 2%). Skeletic Cryosols contained also iron, aluminium, magnesium, manganese, calcium, and sulphur (> 1%). Leptic Andosols were rich in iron and aluminium (> 2%). Soil properties and humic substances quality were evaluted. Results of chemical and physical analyses indicated that poorly developed soils of Antarctica varied in acidity, conductivity, humus content, and texture. Humic substances content and quality were low. Mainly mechanical (physical) and chemical weathering processes played major role in the soil development accompanied by low intensity of biological activity. [ABSTRACT FROM AUTHOR]

Mineralogical composition and microstructural features influence rock strength and their failure mechanisms. Crack initiation (CI) and crack damage (CD) are important processes of the failure mechanisms of rocks. Since CI is the lower limit of the long term strength of rocks at low confinement, this study is mainly concerned with triaxial tests and the determination of CI and CD using different methods. A triaxial cell has been designed to examine spalling behavior of magmatic rocks under low confinement, at minor principal stresses up to 2.5 MPa. Two granites with different grain sizes were tested. Methods to determine CI and CD include the calculation of circumferential, volumetric and crack volumetric strain. In addition, acoustic emission monitoring provides the onset of CI and CD. Uniaxial compressive tests including primary wave velocity measurements as well as acoustic emission were used to supplement the dataset. The wave velocities also give an indirect determination of CI and CD as the initiation of cracks reduces the speed of the waves. This study aims to compare the different methods determining CI and CD and to connect the results with mineralogical and microstructural features. Orientated thin sections were prepared to identify the mineralogical composition. Furthermore, the growing influence of confining pressure from 0.1 to 2.5 MPa on rock strength was analyzed. [ABSTRACT FROM AUTHOR]

An interesting valorisation way of EAF slag and stabilised AOD slag is their use as aggregates in concrete. Mineralogical studies of these steel slags are therefore necessary. In this study, observations of slag aggregates under UV light are associated with usual mineralogical analyses (XRD, SEM and EDS) to ensure more representative results of the mineralogical variability within slag aggregates. Relationships between aggregate mineral composition and UV fluorescence colours are proposed. Mineralogical studies also show that the stainless steel slag contains low amounts of expansive mineral phases (free CaO, free MgO) that could affect concrete volume stability. To verify this finding, swelling measurements of high strength concretes made of EAF slag and stabilised AOD slag aggregates are carried out. The linear expansion of stainless steel slag concretes is slightly higher than that measured for concretes with silico-calcareous aggregates. [ABSTRACT FROM AUTHOR]

Coal fires burning around the world over many years have been responsible for the loss of natural resources and also for negative environmental and human-health impacts. Study of self-burning coal wastes based on organic petrology, mineralogy and geochemistry allows the evaluation of factors responsible for the combustion process, and can also be used to assess the changes that are taking place in thermally affected materials. The main goal of this study is to characterize the materials from the Arroyo Galladas, Arroyo Mourin and Fabero coal waste piles, which resulted from coal mining in the El Bierzo Coalfield (NW Spain). Samples of coal, and of unburned and burned or burning coal waste material, were studied by optical microscopy and X-ray powder diffraction (XRD). The results demonstrate that some of the organic matter has preserved its characteristics, but other organic material shows signs of thermal alteration such as cracks, devolatilization vacuoles, dark reaction rims, plasticized edges, and increased or decreased vitrinite reflectance. The resistance of the unaltered organic matter to thermal effects is attributed to the coalification process previously undergone by these coals. The mineralogical composition of the samples indicates that newly formed minerals are present in the burned or burning material, including mullite, cristobalite, cordierite, hematite, jarosite, sanidine, anorthite, sulfur, pyrite, rozenite, coquimbite, tschermigite, boussingaultite and amorphous material. The formation of these minerals is attributed to combustion at maximum temperatures of at least 1100 °C in the Fabero coal waste pile and lower temperatures in the Arroyo Galladas coal waste pile, and to interaction of gases released by combustion with the solid particles, the waters and the atmosphere in and around the waste piles. [ABSTRACT FROM AUTHOR]

The evolution of the materials used in Portuguese interior wall coatings since the Roman occupation, namely the binders, is investigated using XRD in order to build a preliminary systematic database to contribute to the design and study of compatible products for conservation and repair. The results show that lime was the main binder until the end of the 18th century, with gypsum overcoming its use in the 19th century. A relationship is established between the results and several influencing aspects, namely other cultures, the neighbouring countries and their traditional construction techniques, the availability of raw materials, the purposes/techniques of application and the geographical location. [ABSTRACT FROM AUTHOR]

The Lucknow monuments of the 18th century are large masonry structures built using thin burnt-clay bricks (Lakhauri) and lime-crushed brick aggregate (surkhi) mortars. Investigations were carried out to characterize the engineering properties of old masonry materials and new mortars being used for renovation work. Mechanical properties of reclaimed Lakhauri bricks were found comparable to good quality contemporary bricks of the region. Moreover, X-ray diffraction (XRD) and scanning electron microscopy–energy dispersive X-ray spectrometry (SEM-EDS) analyses indicated that mineralogical composition is not too different, except for few minerals. The lime-surkhi mortar used in old masonry work was found to be lime-rich with binder to aggregate ratio of approximately 1:2 to 3 by volume. The renovation mortar had poor hydraulic property as compared to old mortars indicated by thermal gravimetric analysis–differential thermal analysis (TGA-DTA) analyses. The compressive behavior of multi-wythe recreated Lakhauri masonry prisms was characterized with low compressive strength, low modulus, and significant deformability which result in lower stress demands imposed on the structural assemblages by various environmental forces. [ABSTRACT FROM PUBLISHER]

1) Reporting the thermal conductivity (TC) of plutonic cuttings in the EGS of FORGE. 2) Determining the optimal estimation model for matrix TC of plutonic cuttings. 3) Modal mineralogy permits MTC calculation with mean absolute relative error (MARE) within 10% using the geometric mean model. 4) The MARE will be minimized by choosing the best estimating model based on the cutting's lithology. The thermal conductivity (TC) of rocks plays a significant role in geothermal-related research. The matrix TC (MTC) could be indirectly inferred from modal mineralogy as a parameter incorporated into mixing models instead of the time-consuming direct measurement of cuttings. This approach lacks robust references due to limited study. In this study, we analyzed 44 plutonic drill cuttings data covering from diorite to granite collected from the FORGE Well 58–32, Milford, Utah, including XRD, MTC, and porosity. We employed eight mixing models commonly used in thermal studies to estimate MTC based on mineral composition (determined by XRD). The MTC depends on the quartz content, and there is a positive linear correlation between them, with R2=0.988. For the mean TC of individual mineral phases, the estimation of MTC with outliers removed shows that the geometric mean model provides a better statistical fit to the measured MTC with a mean absolute relative error (MARE) and a root mean squared error (RMSE) of 6.0 ± 4.4% (2σ) and 0.21 W/(m•K), respectively. By selecting the best mixing model considering the cutting's rock types, the MARE, and RMSE between the estimated and measured MTCs are significantly minimized. Therefore, we suggest that in case of the volume of plutonic cuttings is inadequate to support direct measurement of TC, the MTC of plutonic cuttings could be estimated with an acceptable magnitude error by assessing their mineralogy and using the appropriate mixing model according to the rock types. [ABSTRACT FROM AUTHOR]

The potential effects of the mineralogical composition of sediment on the degradation of oil buried on sandy beaches were investigated. Toward that purpose, a laboratory experiment was carried out with sandy sediment collected along NW Iberian Peninsula beaches, tar-balls from the Prestige oil spill (NW Spain) and seawater. The results indicate that the mineralogical composition is important for the physical appearance of the oil (tar-balls or oil coatings). This finding prompted a reassessment of the current sequence of degradation for buried oil based on compositional factors. Moreover, the halo development of the oil coatings might be enhanced by the carbonate concentration of the sand. These findings open new prospects for future monitoring and management programs for oiled sandy beaches. [ABSTRACT FROM AUTHOR]

Abstract: Carbonate nodules at the base of paleosols within Chinese loess are products of pedogenic neoformation and thus have great potential to document the summer monsoon history. Here we present mineralogical and elemental compositions of carbonate nodules from a north–south loess transect of northern China for the last and penultimate interglacials. X-ray diffraction patterns show that the nodules are composed mainly of calcite, together with some silicate minerals such as quartz, plagioclase, orthoclase, illite, and kaolinite. Elemental composition of the acetic acid-leachable fraction is characterized by extremely high Ca concentration and modest K and Mg content, followed by Al, Si, Sr, Mn, Fe, P, Na, Ba, Pb, Th, and U. Based on the mineralogical data and relationship between carbonate and the leachable element content, we suggest that K, Mg, Sr, Ba, and U mainly come from clay minerals, Na from highly soluble salts trapped by calcite particles, and Al and Si from amorphous phases of pedogenic origin. For both the last and penultimate interglacials, the Na content decreases from north to south, while the Al, Si, and U concentrations show a southward-increasing pattern. These characteristics all suggest a southward decrease in aridity across the Chinese Loess Plateau for both interglacials, consistent with the pattern of a southerly increase in pedogenic development for the two interglacial soils, and with the pattern of the present north–south rainfall gradient. Therefore, Na/Al and Na/Si ratios in the acetic acid extract are efficient proxies for aridity and are ultimately controlled by the summer monsoon precipitation, i.e. high ratios indicate weakened summer monsoon intensity. In addition, the significant content of highly soluble Na salts in carbonate nodules highlights soil dewatering as an important mechanism for the formation of pedogenic carbonate, at least in the case of the northern Loess Plateau. [Copyright &y& Elsevier]

• Aeolian silt mantles reveal different clay mineralogy than the underlying substrates. • Aeolian silt admixture was an important source of chlorite. • Smectite and mica have partially been inherited from the underlying bedrock. • Clay minerals transformation determined the presence of vermiculite and smectite. Loess may be integrated into slope deposits at different soil depths and may influence related physical, chemical and mineralogical soil properties. Therefore, tracking the border between deposited loess and underlying materials and estimating the depth of loess penetration is a challenge. Five soils from the Lower Silesia province in south-western Poland having different types of geologic substrate and being covered by loess deposits of various thicknesses were chosen to: 1) trace the origin of phyllosilicates in these heterogeneous soils (loess vs. underlying bedrock); 2) determine the influence of the geologic substrate and the loess mantle on clay mineral transformation in the soil; and 3) relate clay mineralogical traits to soil morphology. The loess consisted of long-distance and local aeolian sources as shown by the Ti/Zr ratios and heavy mineral composition. Geochemical and mineralogical traces of loess were easily detected in the mixed zone and in part also in the basal layer. The loess deposits are characterised by mica, chlorite, kaolinite, interstratified mica-vermiculite or hydroxy-interlayered vermiculite, vermiculite and a minor amount of smectite. Aeolian silt admixture was an important source of chlorite at all sites. The vertical distribution of mica indicated two types of sources — loess input and substrate. Smectite, however, has mostly been inherited from the underlying bedrock (serpentinite, glacio-fluvial deposits and basalt slope sediment) or was formed in the soils from mica or chlorite. Where present in the loess, smectite was only found in small amounts. The presence of kaolinite, HIV and mixed layered mica-vermiculite could be derived either from aeolian input or neoformation and thus actively occurring mineral (trans)formation reactions. Similar to mica, vermiculite was derived from both aeolian input and the geological substrate. The widespread loess deposits in this region rejuvenated the soil formation process, as evidenced by their mineralogical and chemical composition. [ABSTRACT FROM AUTHOR]

The mineralogical composition of the nodular-conglomerate chromium-nickel iron ore of the Serovskoe deposit is studied using chemical, x-ray phase and optical methods of analysis. The material composition of the ore determined by separation into fractions is shown to be complex and inhomogeneous. [ABSTRACT FROM AUTHOR]

Through the determination of mineralogical compositions of the salt rock and gypsum-salt rock in Puguang gas field and the creep experiments on these rocks, the authors analyze the impacts of mineralogical compositions, deviatoric stress, temperature, and confining pressure on creep behavior and proposes the constitutive equation of steady-state creep rate by combining with the creep curve and rock parameters obtained by the experiments. The experiment results indicate that the main mineralogical compositions of the salt rock and gypsum-salt rock in Puguang gas field are sodium chloride and calcium sulfate, where the content of sodium chloride can be up to more than 93%; the inherent mineralogical compositions are the internal factors that impact the creep characteristics of rock, along with the content of sodium chloride increasing, the rates of transient creep and steady-state creep increase accordingly; and as the deviatoric stress and temperature increase, the steady-state creep rate increases too. However, the impact of confining pressure is very small. The authors obtain the parameters of Heard's creep constitutive equation by fitting test data, working out the steady-state creep rates of salt rock and gypsum-salt rock under different deviatoric stresses and temperatures, which provides the theoretical basis of the calculation of safe mud density window and the analysis of abnormal casing deformation for the formations of salt rock and gypsum-salt rock in Puguang gas field. [ABSTRACT FROM AUTHOR]

Kidney stones are a very frequent finding in southern Italy, but stone analysis is not routinely performed. However, it is an important requirement not only for a successful treatment of this disease, but also for the prophylaxis to prevent any recurrence. We therefore set out to analyze 80 kidney stones collected from Basilicata Region (Southern, Italy). X-ray powder diffraction as well as optical and scanning electron microscopy and petrographic thin section analysis have been applied in order to determine the mineralogical and morphological compositions. The internal structure and the relation between major and minor components have facilitated the classification of the kidney stones according to a detailed scheme. As it is known from other country, calcium oxalate stones were the most frequent (59%) [39% mainly composed of whewellite, CaC_2O_4*H_2O and 29% is mainly made of weddellite, CaC_2O_4*2H_2O]. Uric acid stones were abundant too (18%). Calcium phosphate and cystine stone were less. The results of the observations of kidney stones in thin petrographic sections led to the identification of more cores in the same whewellite kidney stones. In some kidney stones the core is not situated in the central zone, which represents the point of attachment on kidney wall. Basilicata kidney stone prevalence is different from the average prevalence determined in other Mediterranean areas. The comparison showed that calcium oxalate stones seem to be more frequent, and there is a high prevalence of uric acid kidney stones and a lower prevalence of phosphate kidney stones, especially hydroxyapatite. The relative increase frequency of uric acid stones in the northern part of the Region may be due to high-purine diets and softness water consumption. [ABSTRACT FROM AUTHOR]

Abstract: Roman pottery excavated from the remains of a villa rustica near Mošnje (Slovenia) was analyzed in terms of its mineralogical and basic geochemical characteristics, to elucidate the technologies of manufacture. Selected samples were examined with optical microscopy, X-ray powder diffraction, SEM–EDS and ICP-OES. Results show that the studied pottery samples can be divided into two main groups based on the nature and size of grains; calcite-tempered pottery and pottery containing predominant fine quartz grains. This mineralogical distinction also reflects differences in production technology. [Copyright &y& Elsevier]

Abstract: Atmospheric dust deposition is a major external iron source for remote surface ocean waters. Organic complexation is known to play a role in the dissolution of iron-containing minerals. In this paper, we present our study on the effect of oxalate on dust iron solubility in simulated rainwater. Our results reveal that the solubility of iron carried by analogs of different African dusts varies with the dust source. Our experiments indicate a positive linear correlation between iron solubility and oxalate concentration. Soluble iron (SFe) increases from 0.0025(±0.0005)% to 0.26(±0.01)% of total iron, considering all dust sources and with oxalate concentrations ranging from 0 to 8 μM. These results show that the observed variability of iron solubility in aerosols collected over the Atlantic Ocean is, at least partly, due to an increase in dust iron solubility, with the presence of oxalate complexation, rather than to the presence of more soluble anthropogenic iron. Considering the mineralogical composition of those particles, experiments with pure minerals (hematite, goethite and illite) were performed to study the dissolution process. We found that oxalate promotes the solubility of iron contained in clay and hence confirmed that more than 95% of SFe from soil dust is provided by clay (illite). This experimental work enables us to establish a parameterization of iron solubility in dust as a function of oxalate concentration and based on the individual iron solubility of pure iron-bearing minerals usually present in dust particles. Finally, our results emphasize that oxalate contributes to iron solubility on the same order of magnitude as the acid processes. Organic complexation appears to be a process that increases iron solubility and likely enhances the bioavailability of iron from dust. [Copyright &y& Elsevier]

The work is devoted to the statistical modeling for short- and long-term predictions of the chemically active properties of the materials by the data on their physical and chemical characteristics measured by non-destructive testing. These materials primarily include products from cement and concrete. Their resistance to compression and bending are the most important quantitative characteristics, which is the basis for the design of various buildings and structures. Information about their strength at a given time, as well as its possible value in the future has the importance paramount in different technological solution. These include problems of establishing optimal mineralogical composition, the definition of moments of time removing formwork, condition monitoring of bridges, dams, power plants and major construction projects, assess their stability, including of natural disasters etc. Statistical analysis of experimental data is the basis for decision-making process, allowing minimization of economic losses. Linear and nonlinear regression modeling of hardening process of such materials is implemented, and an adaptive algorithm is proposed and tested for the prediction of strength and comparative analysis of experimental data. [ABSTRACT FROM AUTHOR]

Abstract: Testate amoebae are increasingly used for environmental monitoring as well as paleoenvironmental reconstructions. Paleoecological interpretations of testate amoebae assemblages depend on the understanding of the ecological processes operating today. We then ask the question of the link between testate structure and its environment. This study analyses both the grain size and mineralogical assemblage of tests of common species belonging to the genus Centropyxis and Difflugia. It is concluded that grain size is a limiting factor for test construction, whereas mineral composition is not. Hence, when analyzing agglutinated testate amoebae for paleoenvironmental reconstructions, it should be taken into account the mean grain size of the sediment. A non-appropriate grain-size probably inhibits the development of a testate amoebae specific assemblage. [ABSTRACT FROM AUTHOR]

Abstract: When sintering artificial lightweight aggregate, rapid cooling will generate micro-cracks. The paper investigates the effect of MgO contents on the physical, chemical and microstructural properties of artificial lightweight aggregate prepared under natural cooling in the furnace (SC) and rapid cooling outside the furnace (RC). Results indicate that cordierite (2MgO⋅2Al2O3⋅5SiO2) starts forming in lightweight aggregate when MgO content reaches 2%, accompanied by a reduction in mullite. Cordierite has a better thermal-shock resistance and its presence minimizes the potential for micro-crack formation, thus decreasing water absorption under rapid cooling conditions for the 2% MgO system. [Copyright &y& Elsevier]