Wide Variation In Composition Research Articles

Polyphenol Composition of Plum Selections in Relation to Total Antioxidant Capacity

Dietary polyphenols are associated with protection against chronic diseases such as cardiovascular disease. Pharmacological studies show a range of bioactivities and efficacy attributable to specific polyphenols. While many fruits are rich in polyphenols, wide cultivar variation of polyphenol composition is common. Our objective was to determine the composition of major bioactive polyphenols in 29 prevarietal selections of Western Australian plums, and Black Amber as an evaluation in developing breeding tools to develop fruit that may have enhanced health-promoting capacities. Total phenolics were quantified colorimetrically; selected polyphenols were quantified by HPLC; and the total antioxidant capacity (TAC) was measured by the antioxidant inhibition of oxygen radicals (AIOR) assay. Total phenolic concentration was significantly correlated with TAC (R = 0.95, P < 0.01). Neo-chlorogenic acid and quercetin glycosides were found to be the predominant polyphenols (mean 29.9 mg·kg(-1) and 50.7 mg·kg(-1), respectively). No significant correlations were found between the composition of predominant polyphenols in plums and the TAC. We argue that the value of in vitro TAC assays to breeding programs may be limited, and future research should focus on the heritability of known bioactive polyphenols.

Geochemical and stable carbon isotopic composition of coal-related gases from the SW Upper Silesian Coal Basin, Czech Republic

Gas associated with Carboniferous coal seams and younger Miocene sediments in the SW Upper Silesian Basin in Czech Republic shows wide compositional variation. Coal-related gas extracted from cross-measure degassing boreholes, as well as gas released during canister desorption of coal samples from three different mines was analyzed to evaluate the genetic origin and the influence of sorption/desorption processes on the gas composition. Analyses comprised the compositional and stable carbon and isotope composition of coal-related gases. The isotopic composition of gas from cross-measure boreholes indicates thermogenic origin in the southern part of the basin and microbial CO2 reduction and mixed type origin in the northern part. Gas from canister desorption shows similar origins, but larger compositional and isotopic variation. No consistent isotopic fractionation due to desorption could be observed. Differences in geochemical composition of thermogenic gases could indicate a contribution of gas migrated from deeper formations below the Carpathian overthrust.

Determination of Polyphenols in Spanish Wines by Capillary Zone Electrophoresis. Application to Wine Characterization by Using Chemometrics

A capillary zone electrophoresis (CZE) method for the simultaneous determination of 20 polyphenols in wine was developed. The separation was performed using fused-silica capillaries of 75 μm i.d. and a 30 mM sodium tretraborate buffer solution at pH 9.2 with 5% isopropanol as a background electrolyte. A capillary voltage of +25 kV with pressure-assisted (3.5 kPa) separation from minute 18 was applied, thus achieving a total analysis time of <25 min. Instrumental quality parameters such as limits of detection (LOD, values between 0.3 and 2.6 mg/L), linearity (r(2) > 0.990), and run-to-run and day-to-day precisions (RSD values lower than 6.5 and 15.7%, respectively) were established. Three different calibration procedures were evaluated for polyphenol quantitation in wines: external calibration using standards prepared in Milli-Q water, standard addition, and pseudomatrix-matched calibration using wine as a matrix. For a 95% confidence level, no statistical differences were observed, in general, between the three calibration methods (p values between 0.11 and 0.84), whereas for some specific polyphenols, such as cinnamic acid, syringic acid, and gallic acid, results were not comparable when external calibration was used. The CZE method using pseudomatrix-matched calibration was then proposed and applied to the analysis of polyphenols in 49 Spanish wines, showing satisfactory results and a wide compositional variation between wines. Electrophoretic profiles and other compositional data (e.g., peak areas of selected peaks) were considered as fingerprints of wines to be used for characterization and classification purposes. The corresponding data were analyzed by principal component analysis (PCA) to extract information on the most significant features contributing to wine discrimination according to their origins. Results showed that a reasonable distribution of wines depending on the elaboration areas was found, tyrosol and gallic, protocatechuic, p-coumaric, and caffeic acids being some representative discriminant compounds.

Defining and describing capacity issues in U.S. Doctor of Nursing Practice programs

Recent calls to expand the number of U.S. Doctors of Nursing Practice (DNPs) raises questions about programs' capacities, content and requirements, and their ability to expand. This paper aims to describe (1) key aspects of DNP program capacities that may provide direction for DNP program expansion plans, the timing of such expansion and program QI efforts; and (2) the impact of the DNP on faculty resources for research doctoral programs. A survey of all U.S. DNP programs (n = 130; response rate 72%) was conducted in 2011 based on previously tested items. Reviews of Web sites of nonresponding schools provided some data from all programs. Ratios of students to faculty active in advanced practice (AP) and in QI (QI) were high (AP 11.0:1, SD 10.1; QI 20.2:1, SD 17.0 respectively). There was wide variation in scholarly requirements (0–4: 50% of program had none) and program committee composition (1–5; mode=2). Almost all responding schools that offered PhD and DNP programs reported assigning research-active or potentially research-active faculty in both programs. The ability to expand programs while maintaining quality may be compromised by capacity issues. Addressing demand issues through the alignment of program requirements with societal and employment requirements may provide directions for addressing current DNP capacity issues.

Improving the nutritional quality and health benefits of wheat

Wheat is an important source of calories (derived from starch), protein, dietary fibre, minerals, vitamins and health-promoting phytochemicals to the human diet. However, many of the beneficial components are concentrated in the outer layers of the grain (bran) and embryo (germ). Consequently, whereas the consumption of whole grain products has health benefits in reducing the risk of a number of medical conditions including the metabolic syndrome, the consumption of highly refined products derived from the starchy endosperm (white flour) may be associated with increased risk. This work will therefore discuss the composition of the wheat grain, focusing on components which positively or negatively affect health outcomes and their distributions in grain tissues and fractions. It will also discuss strategies for developing new types of wheat with improved health benefits, focusing on the three major components in the grain: protein, starch and dietary fibre. Classical plant breeding can be used to increase the content and improve the composition of dietary fibre in flour and wholemeal, exploiting the existence of wide variation in composition and high genetic heritability (Ward et al. 2008; Shewry et al. 2010), and using molecular markers for selection. In particular, increasing the content of soluble fibre content leads to increased intestinal viscosity and reduced glycaemic index (with reduced risk of type-2 diabetes). The glycaemic index of wheat products can also be reduced by increasing the amylose content of starch, and increases from 25% to 40% amylose can be achieved by combining naturally occurring or induced mutations in genes controlling the synthesis of amylopectin (Sestili et al. 2010). The nutritional quality of wheat protein is limited by the low contents of essential amino acids, notably lysine, in the gluten protein fraction. Although high lysine mutations have been studied widely in maize and barley, they have achieved little commercial success and this approach has not been adopted in hexaploid bread wheat. However, lessons learned from studies in these cereals should allow the use of genetic engineering to improve the protein quality of wheat. The combination of these traditional and novel approaches will allow the development of new types of wheat with enhanced nutritional quality and health benefits for wholegrain and white products.

Trace Fossil Assemblages in Mixed Siliciclastic-Carbonate Sediments of the Kaladongar Formation (Middle Jurassic), Patcham Island, Kachchh, Western India

Abstract The Middle Jurassic rocks of the Kaladongar Formation well exposed in the Kaladongar Hill range of the Patcham Island and Kuar Bet of the Northern Kachchh comprises of ∼450 m thick sequence of mixed siliciclastic-carbonate sediments intercalated with shales. These Mixed siliciclastic-carbonate sediments show wide variation in textural and mineralogical composition and represent genetically related six rock types: micritic sandstone, allochemic sandstone, sandy allochemic limestone, micrtic mudrock, sandy micrite and muddy micrite; which are highly bioturbated and show behaviourally diverse groups of trace fossils. Total 34 ichnogenera are identified, which includes, Arenicolites, Asterosoma, Beaconites, Bergaueria, Chondrites, Cochlichnus, Dactylophycus, Daedalus, Didymaulichnus, Diplocraterion, Gordia, Gyrochorte, Gyrolithes, Ichnocumulus, Laevicyclus, Lockeia, Margaritichnus, Monocraterion, Nereites, Ophiomorpha, Palaeophycus, Phoebichnus, Phycodes, Pilichnus, Planolites, Plug Shaped Form, Protovirgularia, Rhizocorallium, Scolicia, Skolithos, Taenidium, Teichichnus, Thalassinoides and Walcottia. These trace fossils are classified into six morphological groups namely, circular and elliptical structures; simple structures; branched structures; rosette structures; spreiten structures; and winding and meandering structures. These trace fossils are further group into eight assemblages which occurred together into mixed siliciclastic-carbonate sediments, include, Asterosoma assemblage, Gyrochorte assemblage, Rhizocorallium assemblage, Thalassinoides assemblage, Planolites-Palaeophycus assemblage, Phycodes assemblage, Ophiomorpha assemblage and Skolithos assemblage. The recurring pattern of these assemblages through the sequence displays the development of Skolithos and Cruziana ichnofacies and at places the mixed Skolithos-Cruziana ichnofacies which suggest a low wave and current energy conditions with intervening period of high wave and current energy conditions and an intermediate period of stressful environments, respectively. Sedimentological and ichnological data suggest that the deposition of the mixed siliciclastic-carbonate sediments of the Kaladongar Formation took place in the foreshore to offshore environment under fluctuating wave and current energy condition.

Comparison of lithology and tectonometamorphic evolution of units at the northern margin of the Moldanubian Zone: implications for geodynamic evolution in the northeastern part of the Bohemian Massif

*Corresponding author Multidisciplinary research evaluates structural, metamorphic and petrochemical data of selected rock types in different units located in the northeastern part of the Bohemian Massif, Czech Republic: (1) the Stražek Unit in the northeastern part of the Moldanubian Zone, (2) the Svratka and Kutna Hora units correlated with the Orlice–Sněžnik Unit in Western Sudetes as well as (3) the Policka, Hlinsko and Zabřeh units belonging to the Tepla–Barrandian Zone. Petrochemical data for metasediments of the Policka, Hlinsko and Zabřeh units are mutually comparable and confirm a lithologi cal affinity to the upper-crustal Tepla–Barrandian Zone. The FeO t /MnO ratios in metasediments of the Stražek Unit and the Svratka Unit indicate differences in the origin of sedimentary protolith rocks. Relict pre-Variscan structures, including extensive migmatization, and high-grade mineral assemblages with peak metamorphic pressures of ~1.4 GPa in skarn bodies, are preserved in the Svratka Unit. The evidence for Palaeo-Variscan (390–355 Ma) HP and UHP events, recorded in the high-grade Kutna Hora and Orlice–Sněžnik units, was observed neither in the NE part of the Moldanubian Zone (Stražek Unit) nor the Tepla–Barrandian Zone (Policka and Zabřeh units). The Variscan orogenic event imprinted in the Svratka, Policka and Zabřeh units was the right-lateral slip along WNW–ESE trending shear zones. This deformation was accompanied by metamorphism at ~580–650 °C and ~0.5–0.7 GPa (352–343 Ma) and intrusion of numerous small bodies of syn-deformation calc-alkaline granitoids in the Policka and Zabřeh units. The younger metamorphic fabrics in the northeastern part of the Moldanubian Zone reflect a fast exhumation of deep-seated high-grade complexes at ~340 Ma, which was constrained by post-tectonic emplacement of durbachites at ~339 Ma. Metamorphic development in felsic granulites of the Stražek Unit, metamorphosed c. 340 Ma ago at 850 °C and 1.8 GPa, was followed by decompression to T ≅ 790 °C and P = 1.3 GPa and finally T = 700 °C and P = ~0.4 GPa. In contrast, Běst vina granulite in the Kutna Hora Unit, with the ~360 Ma high-grade metamorphism at 800–920 °C and 1.8–2.1 GPa, is free of such a HT–LP overprint. Thus the data indicate that the Svratka and Kutna Hora units, exhibiting numerous mutual differences, should not be considered as belonging to the Moldanubian Zone as they evolved as independent entities. The geochemical data on garnet–clinopyroxene skarns from the Moldanubian Zone, the Svratka and Kutna Hora units do not provide mutually distinguishing features. This is largely due to a very wide compositional variation in rocks interpreted as metamorphosed exhalite with detrital material admixture. Skarns from the Svratka Unit preserve clinopyroxenes with elevated jadeite component (0.5–24 mol. %) and prograde compositional zoning in garnet – features obliterated in samples from the Moldanubian Zone and the Kutna Hora Unit.

Investigation of Combined Effect of Mixture Variables on Mechanical Properties of Cement Treated Demolition Waste

One of high efficient ways to reuse the recycled construction and demolition waste (CDW) is to consider it as a road base material. The recycled CDW however is mainly a mix of recycled masonry and concrete with a wide variation in composition. This results that the mechanical properties of cement treated demolition waste are not only determined by cement content and degree of compaction, but also by the composition ratio of masonry to concrete. This paper investigates the combined effect of those three mixture variables on the mechanical properties of cement treated demolition waste by using response surface technique. The evaluated mechanical properties include the unconfined compressive strength (UCS), the elastic modulus and their ratio. Analytical results indicate that increasing the degree of compaction is an economic technique to obtain the required mechanical properties, but it is not an efficient method to enhance the admissible elastic strain (the ratio of UCS to E). Considering the pavement structure design with cement treated demolition base, improvement of its structural performance needs adjusting the masonry content and the cement content.

Enzymatic fingerprinting of arabinoxylan and β-glucan in triticale, barley and tritordeum grains

Enzymatic fingerprinting of arabinoxylan (AX) and β-glucan using endo-xylanase and lichenase, respectively, helps determine the structural heterogeneity between different cereals and within genotypes of the same cereal. This study characterised the structural features of AX and β-glucan in whole grains of eight triticale cultivars grown at two locations, 20 barley cultivars/lines with wide variation in composition and morphology and five tritordeum breeding lines. Principal component analysis (PCA) resulted in clear clustering of these cereals. In general, barley and tritordeum had a higher relative proportion of highly branched arabinoxylan oligosaccharides (AXOS) than triticale. Subsequent analysis of triticale revealed two clusters based on growing region along principal component (PC) 1, while PC2 explained the genetic variability and was based on mono-substitution and di-substitution in AX fragments. PCA of β-glucan features separated the three cereals based on β-glucan content. The molar ratio of trisaccharide to tetrasaccharide was 2.5–3.4 in triticale, 2.3–3.3 in barley and 2.8–3.4 in tritordeum. Barley showed a strong positive correlation (r=0.86) between β-glucan content and relative proportion of trisaccharide. The results show that structural features of AX and β-glucan vary between and within triticale, barley and tritordeum grains which might be important determinants of end-use quality of grains.

Hg-bearing sphalerite from the Rujevac polymetallic ore deposit, Podrinje Metallogenic District, Serbia: Compositional variations and zoning

Rujevac is a low-temperature hydrothermal polymetallic Sb(As)–Pb–Zn vein-type ore deposit, hosted in volcanogenic-sedimentary zone situated in Rujevac-Crvene Stene-Brezovica Diabase-Chert Formation (DCF) of the Podrinje Metallogenic District (PMD), Serbia. The mineralogical composition of the deposit consists of sulfides (stibnite, sphalerite, pyrite, arsenopyrite, galena, realgar and orpiment), sulfosalts (zinkenite, plagionite, robinsonite, twinnite and gratonite), native arsenic, Sb-oxides (valentinite, senarmontite and kermesite), and gangue minerals (quartz, calcite and dolomite). Minerals containing mercury as a major element have not been detected. According to optical features, sphalerite belongs to the cleophane, low Fe content variety (yellowish to colorless). Electron Probe Micro-Analyses (EPMA) of sphalerite revealed wide compositional variations. The Hg content in sphalerite varies between 0.30 and 6.47wt%. The range of other minor elements (Fe and Cd) is highly variable; Mn, Sn, Ge, In, Tl, and As were analyzed, but not detected. Hg-rich zones occur as narrow lamellae and are related to the crystallographic directions of sphalerite. The average values of the EPMA results gave the crystallochemical formula of this sphalerite (Zn0.981, Fe0.007, Cd0.007, Hg0.008)∑1.003S0.997. Strong negative correlations have been determined between ∑Fe+Cd+Hg vs. Zn, and Hg vs. Zn, while these are absent between all other analyzed elements.

Developing new types of wheat with enhanced health benefits

The consumption of wholegrain wheat is associated with a number of health benefits which may relate to the presence of a range of dietary fibre, phytochemical, vitamin and mineral components. Analysis of 150 bread wheat lines within the HEALTHGRAIN programme showed wide variation in content and composition of bioactive components within 150 bread wheat lines. Furthermore, in some cases (notably arabinoxylan in flour and tocols, sterols and alkylresorcinols in wholemeal) this variation was highly heritable and hence accessible to plant breeders. A number of tools are therefore being developed to facilitate the selection of these components in plant breeding programmes including molecular markers, biochemical kits and NIR calibrations.

Further Evaluation of Fluoride Dating by Ion Selective Electrode Analysis

Fluoride dating by ion selective electrode (ISE) analysis is a viable relative dating technique for dense cortical bone from archaeological sites. The fluoride content of cortical bone and rate of absorption is directly related to the porosity and microstructure of the sample and post-depositional environmental variables including the CaF2 content of the bedrock, soil, and changes in groundwater levels, flow rates, and chemical composition. Dense diaphyseal cortical bone from homogenous sediment contexts exposed to consistent groundwater chemistry through time is the best sample for fluoride dating by the ISE technique. Teeth should not be used as samples for fluoride dating because differences in the porosity and permeability of enamel can produce wide variations in composition.

Mixture optimization of cement treated demolition waste with recycled masonry and concrete

Due to environmental reasons and the shortage of natural resources, it is greatly valuable to recycle construction and demolition waste (CDW) as much as possible. One of effective ways to reuse more CDW is to produce a cemented road base material. The recycled CDW however is a mix of recycled masonry and concrete with a wide variation in composition. This implies that the mechanical properties of cement treated demolition waste are not only determined by cement content and degree of compaction, but also by the ratio of crushed masonry content to crushed concrete content. In order to optimize its mixture proportioning, this paper explores the response surface and contour plot of the combined effect of mixture variables on the mechanical properties including the unconfined compressive strength (UCS), the elastic modulus (E) and their ratio. It has been recognized that optimizing the mixture proportioning of cement treated demolition waste should not only consider its material properties, but also needs to take into account its structural behavior as a pavement layer. Analytical results indicate that increasing the degree of compaction is an economic technique to obtain the required strength, but it is not an efficient method to enhance the admissible elastic strain (the ratio of UCS to E) and to improve the flexural rigidity of the road base layer. Obtaining a desired low flexural rigidity certainly needs adjusting of the masonry content and the cement content.

Occurrence of an Alaskan-type complex in the Middle Tianshan Massif, Central Asian Orogenic Belt: inferences from petrological and mineralogical studies

The Xiadong mafic–ultramafic complex lies in the central part of the Middle Tianshan Massif (MTM), along the southern margin of the Central Asian Orogenic Belt (CAOB). This complex is composed of dunite, hornblende (Hbl) clinopyroxenite, hornblendite, and Hbl gabbro. These rocks are characterized by adcumulated textures and variable alteration. Orthopyroxene is an extremely rare mineral in all rock units and plagioclase is absent in dunite and Hbl clinopyroxenite. Hbl, Fe-chromite, and Cr-magnetite are common phases. Olivines have forsterite (Fo) contents ranging from 92.3 to 96.6. Clinopyroxenes are Ca-rich, Ti-poor diopsides, and mostly altered to tremolites or actinolites. Chromites display low TiO2 and Al2O3 contents and high Cr# and Fe2+/(Fe2+ + Mg) values. Primary and secondary Hbls show wide compositional variations. These petrological and mineralogical features as well as mineral chemistry are comparable to typical Alaskan-type complexes worldwide, which are widely considered to have formed above subduction zones. The chemistry of clinopyroxene and chromite supports an arc plate-tectonic origin for the Xiadong complex. Its confirmation as an Alaskan-type complex implies that the MTM, with Precambrian basement, was probably a continental arc during oceanic plate underflow and further supports the hypothesis of southward subduction of the Palaeozoic Junggar Ocean.

Oceanic core complex development at the ultraslow spreading Mid‐Cayman Spreading Center

Roughly a third of the global mid‐ocean ridge system spreads at &lt;20 mm/yr (full rate) with predicted low crustal thicknesses, great axial depths, end‐member basalt compositions, and prominent axial faults. These predictions are here further investigated along the ultraslow (15–17 mm/yr) Mid‐Cayman Spreading Center (MCSC) through a compilation of both previously published and unpublished data. The MCSC sits along the Caribbean‐North American plate boundary and is one of the world's deepest (&gt;6 km) spreading centers, and thought to accrete some of the thinnest (∼3 km) crust. The MCSC generates end‐member mid‐ocean ridge basalt compositions and hosts recently discovered hydrothermal vents. Multibeam bathymetric data reveal that axial depth varies along the MCSC with intraridge rift walls defined by kilometer‐scale escarpments and massifs. Dredging and near‐bottom work has imaged and sampled predominantly basaltic lavas from the greatest axial depths and ∼15% peridotite surrounded by gabbroic rocks from the prominent massifs. The gabbroic rocks exhibit wide compositional variation (troctolites to ferrogabbros) and in many places contain high‐temperature (amphibolite to granulite facies) shear zones. Gabbroic compositions primarily reflect the accumulation of near‐liquidus phases that crystallized from a range of basaltic melts, as well as from interactions with interstitial melts in a subaxial mush zone. Magnetization variations inverted from aeromagnetic data are consistent with a discontinuous distribution of basaltic lavas and structurally asymmetric spreading. These observations support an oceanic core complex model for MCSC seafloor spreading, potentially making it a type example of ultraslow seafloor spreading through mush zone and detachment fault crustal processes.

Oxidized magmatogene fluids: metal-bearing capacity and role in ore formation

Based on study of fluid and melt inclusions in minerals from igneous rocks and associated ore-metasomatic objects, we consider the formation conditions of oxidized fluids produced at the final stages of differentiation of alkali-basic, alkaline, lamproitic, and some granitoid melts. These fluids are characterized by wide variations in composition, concentrations, and physicochemical parameters ( P, T, Eh, pH, etc.) and are of sulfate-chloride, sulfate-carbonate, sulfate-fluoride, fluoride-sulfate, essentially sulfate, and other types. The specific composition of these magmatogene fluids showing a high extractive power favors the effective removal of ore-forming elements (Fe, Mn, Co, N, Ag, Cu, Pb, Zn, Mo, W, Bi, U, REE, etc.) from melt and their trapping from the host rocks. The set of these elements is determined by P-T-X-parameters, conditions of fluid separation from melts, composition of fluid-generating magmas, and geochemical composition and metal-bearing capacity of rocks through which the fluids migrate. These factors significantly determine the metallogeny of alkaline, alkali-basic, and some granitoid complexes and associated mineralization.

Changes in Glycerolpipids and their Fatty Acids Composition During Maturation of Coriander (Coriandrum sativum L.) Fruits

Coriander fruits were harvested at three stages of maturity from Menzel Temime region.Oil yield and glycerolipid fractions were studied. The first results showed that oil yield increased significantly(P<0.05) during fruit maturation. At full ripeness neutral lipids (NL) quantities were higher than those ofpolar lipids (PL) and represented mainly by the triacylglycerol (TAG) fraction (96.67 ± 10.41 %) which wasaccumulated dramatically during fruit maturation. During maturation, saturated fatty acids (SFA) andpolyunsaturated fatty acids (PUFA) decreased significantly (P<0.05) while monounsaturated fatty acids (MUFA)increased considerably. At full maturation, petroselinic acid is the main compound with a considerablepercentage 82.54 ± 9.16 % followed by oleic (12.89 ± 1.32 %) and palmitic (3.43 ± 0.21 %) acids. Petroselinicand palmitic acids follow evolutionary changes in opposite directions in TAG, diacylglycerol (DAG) andgalactolipids (GL) except in phospholipids (PhL) were, they follow the same trend of evolution duringmaturation. Obtained results have revealed wide variation in total lipid (TL), glycerolipid fractions and fattyacid composition, offering possibilities to choose the best quality of edible and specialized industrial oils.

Characterisation of Typical Indian Iron Ore Slime through Quantitative Mineralogy to Evaluate Beneficiation Prospect

The current work was taken up to predict the yield of the concentrate with 2 mass% target alumina from the available iron ore slime material. It was found that the conventional method was not suitable for characterisation of the slime. As an alternative method, a third generation of automated mineral analysis machine named “QEMSCAN” is used to find out the liberation characteristics. However, data generated through this routine method was also inadequate for the assigned job. The routine method predicted a low yield for the concentrate. This was due to skewed distribution of mineral phases and wide variation in chemical composition of the major mineral phases. The database of this machine was then modified so that it recognises three broad subtypes of the major mineral phase. The new set of data was used to establish the yield–grade relation for the concentrate from the slime. This vital information on liberation characteristics depicted the beneficiation prospect of the slime.

Geochemistry and mineralogy of Ogun phosphate rock.

Suitability of direct application of phosphate rock as low cost phosphorus fertilizer for crop production must be environmentally safe. Four pellets of Ogun phosphorites labeled OG1, OG2, OG3 and OG4 were randomly selected and subjected to petrographic, X-ray diffraction and X- ray fluorescence analyses. Petrographic results revealed two textural forms: nodular (OG1 and OG3) and granular (OG2 and OG4). Characteristic features like fine grains of phosphorites, geopedal texture with heavy iron staining were found in nodular form while presence of shell fragments and bioclastic materials with burrows were observed in granular form. The diffractogram of different pellets showed poorly crystalline mineral, flourapatite was identified as the major apatite mineral. X-ray fluorescence results showed wide variations in elemental composition among the different forms of Ogun phosphorites. In nodular phosphorites (OG1 and OG3), apatite content were 31.28 and 30.20% P 2 O 5 respectively, Granular phosphorites (OG2 and OG4) contain 19.73 and 11.12% P 2 O 5 . The alkali metals K 2 O and Na 2 O are variable and low showing its suitability as P source because minimal salt is added to the soil. Radionuclides present have low values (U 19 to 29 ppm; Th 5 to 13 ppm; Ni 41 to 80 ppm) indicating its environmental security. Key words: Phosphorus, phosphorites, Ogun phosphate rock, x-ray fluorescence analysis, x-ray diffraction analysis, petrography analysis.

Aluminium phosphate and phosphate-sulphate minerals in kyanite schists of the Ichetuyskoye area, West Transbaikalia, Russia: crystal chemistry and evolution

Aluminium phosphate and aluminium phosphate-sulphate (APS) minerals occur as disseminated crystals and fine-grained aggregates in kyanite schists near Ichetuyskoye, in the Dzhida basin (West Transbaikal region, Russia). Petrographical, mineralogical and geochemical data suggest a metamorphic evolution through prograde and retrograde stages. Lazulite-scorzalite and trolleite in association with kyanite, quartz, muscovite, paragonite, topaz, rutile, magnetite and hematite formed during the prograde stage. More than 25 minerals identified in schists are genetically related to the retrograde stage. Some phosphates and all of the APS minerals belong to the alunite, beudantite and plumbogummite groups. Electron-microprobe data reveal the presence of wide compositional variations and complex solid-solution series among the members. The main crystal-chemical variations of the APS solid-solution series in the alunite supergroup concern the relative proportions of svanbergite, woodhouseite, goyazite, crandallite, florencite-(Ce) and natroalunite. Chemical analyses of APS minerals indicate extremely high amounts of LREE, Sr, Ba, Ca and Na. In some cases, APS minerals have compositions of Ba and Ca,Ba phosphates– sulphates.