Variation In Mineral Composition Research Articles

Fourier Transform Infrared Imaging Microspectroscopy and Tissue-Level Mechanical Testing Reveal Intraspecies Variation in Mouse Bone Mineral and Matrix Composition

Fracture susceptibility is heritable and dependent upon bone morphology and quality. However, studies of bone quality are typically overshadowed by emphasis on bone geometry and bone mineral density. Given that differences in mineral and matrix composition exist in a variety of species, we hypothesized that genetic variation in bone quality and tissue-level mechanical properties would also exist within species. Sixteen-week-old female A/J, C57BL/6J (B6), and C3H/HeJ (C3H) inbred mouse femora were analyzed using Fourier transform infrared imaging and tissue-level mechanical testing for variation in mineral composition, mineral maturity, collagen cross-link ratio, and tissue-level mechanical properties. A/J femora had an increased mineral-to-matrix ratio compared to B6. The C3H mineral-to-matrix ratio was intermediate of A/J and B6. C3H femora had reduced acid phosphate and carbonate levels and an increased collagen cross-link ratio compared to A/J and B6. Modulus values paralleled mineral-to-matrix values, with A/J femora being the most stiff, B6 being the least stiff, and C3H having intermediate stiffness. In addition, work-to-failure varied among the strains, with the highly mineralized and brittle A/J femora performing the least amount of work-to-failure. Inbred mice are therefore able to differentially modulate the composition of their bone mineral and the maturity of their bone matrix in conjunction with tissue-level mechanical properties. These results suggest that specific combinations of bone quality and morphological traits are genetically regulated such that mechanically functional bones can be constructed in different ways.

Surface Studies of Centrifugally Cast Aluminum-based Lead Bearing Composites

Low cost and abundant availability of aluminum—based composites make them potential candidates for bearing applications. The dispersion of lead is difficult in aluminum, so a centrifugal casting procedure has been adopted for uniform dispersion. Cylindrical castings show minor variation in composition from outer to inner as well as from top to bottom. Wear rate shows an increasing trend with sliding distance and load. But with sliding velocity wear rate initially decreases, attains a minimum, and then increases sharply with increase in sliding velocity. Under dry sliding conditions all alloys exhibit two regimes of wear, viz. mild wear at low loads and sliding velocities but severe wear at higher loads and sliding velocities. These two wear mechanisms are distinguished by a mixed mode of oxidative and metallic wear dominated by either.

Sea level induced variations in clay mineral composition in the southwestern South China Sea over the past 17,000 yr

Variations in clay mineral composition of sediment cores from the margin and continental slope of the Sunda Shelf (southern South China Sea, SE Asia) covering the past 17,000 yr reflect changing influences of sediment sources together with clay mineral partitioning processes in shallow waters. We identify the deglacial sea level rise as the principal factor driving these changes. During the late glacial, high values of kaolinite are interpreted to reflect a higher contribution of clays from soils that have formed on the exposed Sunda Shelf and in the southern archipelagos of Indonesia. At this time core sites were located in close proximity to the mouths of the Sunda Shelf palaeo-drainage systems on the emerged shelf (“Sundaland”). The progressive landward displacement of the coastline and breakdown of these vast drainage systems during deglaciation led to a decrease in influence of the kaolinite-rich southern sources. When the coastline had retreated closely to its present-day position in mid-Holocene times, the former dominance of southern sources was replaced by a stronger influence of illite-rich sources (e.g. Borneo). The overriding control of sea level changes on the clay mineral distribution patterns precludes a definite climatic interpretation of clay mineral data in terms of climatic/monsoonal changes in such highly dynamic sedimentary environment.

Sources of material for massive sulfide deposits in the Urals: Evidence from the high-precision MC-ICP-MS isotope analysis of Pb in galena

This work reports the results of one of the pioneer investigation of the Pb isotope geochemistry based on modern high-precision multichannel mass spectrometry with inductively coupled plasma (MC-ICP-MS). We studied the main mineral and age groups of massive sulfide deposits in the Urals: superlarge Gai deposit (~9 Mt); large deposits, such as Sibai (Cu + Zn, ~3 Mt), Uchaly (~7 Mt), and Saf’yanov (~2 Mt); and eight medium and small deposits. The lead isotopic compositions of these deposits were studied in 54 galena samples. According to Albarede [1], the MC-ICP-MS method has opened “a new era in isotope geochemistry,” particularly in the study of the Pb isotopic composition [2, 3]. Until recently, the method of thermoionization mass spectrometry (TIMS) dominated in this field. The overwhelming majority of Pb isotope data reported in the world during the last 50 years is based on the TIMS measurement of 206 Pb/ 204 Pb, 207 Pb/ 204 Pb, and 208 Pb/ 204 Pb ratios with an error of 0.1‐0.2% or more. Application of the MC-ICP-MS method decreased the error by 5‐ 10 times. Therefore, it has become possible to investigate minor local and regional variations in the Pb isotopic composition, decrease significantly (from ± 35 to ± 4 Ma) the analytical error of the model Pb‐Pb age calculation, and unravel “short” correlation trends of the isotopic characteristics of Pb. We have developed and applied a special MC-ICPMS version based on the NEPTUNE (ThermoFinnigan) device at the Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry (Moscow). The method consists in the high-precision isotopic analysis of Pb from Tl-doped solutions and the normalization of all current Pb isotope data relative to the

Metasomatism induced by alkaline magma in the upper mantle of northern Victoria Land (Antarctica): an experimental approach

AbstractMagma generation in the Ross Sea system is related to partial melting of strongly metasomatized mantle sources where amphibole most probably plays a crucial role. In this context, metasomatism induced by a mela-nephelinite melt in lithospheric mantle of the Mt. Melbourne Volcanic Province (northern Victoria Land (NVL), Antarctica) was investigated experimentally studying the effects of melt interaction with lherzolite at 1.5–2.0 GPa and T=975–1300 °C, and wehrlite at 1.0 GPa and T=1050–1250 °C. The experiments were designed to induce melt infiltration into the ultramafic rocks. The observed modifications in minerals are compared with those found in mantle xenoliths from NVL. The effects of metasomatic modifications are evaluated on the basis of run temperature, distance from the infiltrating melt and the diffusion rates of chemical components. Both in lherzolite and wehrlite, clinopyroxene exhibits large compositional variations ranging from primary diopside to high-Mg–Cr–(Na) augitic and omphacitic clinopyroxenes in lherzolite, and to low-Mg and high-Ti–Al–Fe–Na augites in wehrlite. Olivine (in wehrlite) and spinel (in lherzolite) are also compositionally modified: the former shows enrichment in Fe and the latter displays a higher Cr/(Cr+Al) ratio. The systematic variations in mineral compositions imply modifications of the chemistry of the infiltrating melt as recorded by the glass veinlets and patches observed in some charges. In experiments involving wehrlite paragenesis, the glass composition approaches that of melt patches associated with both amphibole-free and amphibole-bearing natural samples, and is related to olivine + clinopyroxene crystallization coupled with primary clinopyroxene dissolution at the contact between the metasomatizing melt and the solid matrix. Even if amphibole crystallization was not attained in the experiments, we were able to explain the occurrence of amphibole in the natural system considering that in this case a hot metasomatizing melt infiltrates a cooler matrix.

Sediment and nutrient accumulation rates in sediments of twelve New Zealand lakes: influence of lake morphology, catchment characteristics and trophic state

Intact sediment cores were collected from the deepest basins of 12 lakes in the Rotorua District, New Zealand, to test for effects of morphological features, catchment characteristics and lake trophic state on net sedimentation rates and sediment nutrient concentrations. Multiple linear regression was used to show that 68% of the variation in net sedimentation rates across the lakes could be explained by lake trophic state and catchment area. Comparison of 2006 data with results from a survey in 1995 showed that surficial sediment (0–2 cm) total phosphorus concentrations (TP) have increased in three of the 12 lakes, at rates ranging from 27.5 to 114.4 mg P kg–1 dry wt y–1. Total nitrogen (TN) concentrations in surficial sediments have increased in nine of the 12 lakes at rates ranging from 51.8 to 869.2 mg N kg–1 dry wt y–1. Temporal changes in sediment TP and TN concentrations were not significantly linearly related (P = 0.12–0.88) to catchment area or different water column indices considered to reflect lake trophic state, including annual mean water column concentrations of TP, TN or chlorophyll a. It is concluded that between-lake variations in sediment TP and TN concentrations are influenced by a range of complex interacting factors, such as sediment redox conditions (and periodic anoxia in the hypolimnion of some lakes) as well as variations in sediment mineral composition (which influences retention and release of various sediment phosphorus and nitrogen species). Subsequently, these factors cause sediment TP and TN concentrations across the 12 lakes to respond differently to temporal changes in water column TP and TN concentrations.

Mineral Compositions and Elements Concentrations as Indicators for the Role of Groundwater in the Development of Landslide Slip Zones: a Case Study of Large-scale Landslides in the Three Gorges Area in China

Reduction of shear strength in landslide slip zone is one of the fundamental mechanisms for landsliding. The causes of decrease in shear strength in landslide slip zones are keys to the understanding of landslide mechanism and to the prediction of landsliding events. Groundwater within slope is known to play an important role in reducing shear strength in landslide slip zones during the development of landsliding physical and chemical interactions with solid phases in the slip zones. In this paper, we report the results of a case study that shows the role of groundwater during the development of landsliding. The physical and chemical effects of groundwater in reducing shear strength in these slip zones may be evaluated by examining the variations of mineral compositions and major elements within the slip zones and surrounding areas. The characteristics of mineralogy and geochemistry of two large-scale landslides in the Three Gorges area, China, the No. 1 Linjiang landslide at Huangtupo and the Xietan landslide, reveal that these slip zones developed along pre-existing weak zones within the slopes. Particularly, minerals and elements that are reactive with groundwater within the landslides indicated that groundwater within the slip zone of the No. 1 landslide at Huangtupo is recharged by rainfall, which caused oxidation within the slip zone. The shear strength reduction in the slip zone could have resulted from physical and chemical processes involving hydrolyses, argillation of marls fragments, dissolution of calcite, and transformation of illite to interlayered illite and smectite. In contrast, groundwater in the slip zone of Xietan landslide has little rainfall component. Consequently, reduction is overwhelming, and shear strength decrease in the slip zone during its development was largely caused by chemical weathering of feldspar and transformation of illite to interlayered illite and smectite.

Plant and soil lipid modifications under elevated atmospheric CO 2 conditions: I. Lipid distribution patterns

Grassland soils are regarded as one potential sink for atmospheric CO 2 via photosynthetic fixation in plant biomass and subsequent transformation into soil organic matter upon degradation. In the future, an enrichment in atmospheric CO 2 concentration is expected, leading to modified photosynthetic activity in plant biomass. Free air CO 2 enrichment (FACE) experiments provide an opportunity for investigating under field conditions plant behaviour expected under future atmospheric composition. Lipid components are important constituents of plant surfaces, whereby their position at the plant/atmosphere interface leads to a high susceptibility towards environmental change. The main focus of this study was an investigation of the modification in lipid distribution patterns within plant biomass and the translocation of these lipids towards, and fixation within, soil organic matter as a result of enhanced CO 2 concentration. We demonstrate which lipids are mainly influenced under modified CO 2 concentrations and show how this affects the lipid composition of plant biomass and soil. Carboxylic acid, alcohol and aliphatic hydrocarbon distribution patterns of plant biomass and soils are discussed. While short chain acids reveal a uniform depletion in unsaturated C 18 acids in plants and soils under enhanced CO 2 concentration, the alcohol fraction shows diverse trends for Lolium perenne and Trifolium repens plants and soil. Long chain alcohols increase in abundance for L. perenne and decrease for T. repens samples. The n-alkanes in soil, as degradation products of plant-derived acids and alcohols, exhibit minor compositional variation. Decreasing amounts of plant-derived acids vs. increasing concentrations of alcohols are noted for T. repens samples. The study demonstrates the response on the molecular level of selected plants under enhanced atmospheric CO 2 concentration. Lipid compositional variation is modified by photosynthetic activity and adapted biosynthesis under future atmospheric conditions may be expected.

The Grader layered intrusion (Havre-Saint-Pierre Anorthosite, Quebec) and genesis of nelsonite and other Fe–Ti–P ores

The Grader layered intrusion is part of the Havre-Saint-Pierre anorthosite in the Grenville Province (Quebec, Canada). This intrusion has a basin-like morphology and contains significant resources of Fe–Ti–P in ilmenite and apatite. Outcropping lithologies are massive oxide alternating with anorthosite layers, banded ilmenite–apatite–plagioclase rocks and layered oxide apatite (gabbro-)norites. Drill cores provide evidence for stratigraphic variations of mineral and whole rock compositions controlled by fractional crystallization with the successive appearance of liquidus phases: plagioclase and ilmenite followed by apatite, then orthopyroxene together with magnetite, and finally clinopyroxene. This atypical sequence of crystallization resulted in the formation of plagioclase–ilmenite–apatite cumulates or “nelsonites” in plagioclase-free layers. Fine-grained ferrodiorites that cross-cut the cumulates are shown to be in equilibrium with the noritic rocks. The high TiO 2 and P 2O 5 contents of these assumed liquids explains the early saturation of ilmenite and apatite before Fe–Mg silicates, thus the nelsonites represent cumulates rather than crystallized Fe–Ti–P-rich immiscible melts. The location of the most evolved mineral and whole rock compositions several tens of meters below the top of the intrusion, forming a sandwich horizon, is consistent with crystallization both from the base and top of the intrusion. The concentrations of V and Cr in ilmenite display a single fractionation path for the different cumulus assemblages and define the cotectic proportion of ilmenite to 21 wt.%. This corresponds to bulk cotectic cumulates with ca. 8 wt.% TiO 2, which is significantly lower than what is commonly observed in the explored portion of the Grader intrusion. The proposed mechanism of ilmenite-enrichment is the lateral removal of plagioclase due to its relative buoyancy in the dense ferrodiorite melt. This plagioclase has probably accumulated in other portions of the intrusion or has not been distinguished from the host anorthosite.

Chemical Composition of Pulicaria dysenterica (L.) Bernh. from Greece

The chemical composition of the aerial parts oil of Pulicaria dysenterica (L.) Bernh. was examined by GC and GC/MS. Oils hydrodistilled from samples collected from two different locations in Greece were found to possess minor compositional differences but considerable variation in the levels of some components. Fifty-four components were identified representing 80.5% (sample A) and 72.6% (sample B) of the total oils. The main components in sample A were (Z)-nerolidol (11.2%), caryophyllene oxide (9.1%) and (E)-nerolidol (6.6%), while those of sample B were β-caryophyllene (12.8%), caryophyllene oxide (12.8%) and (E)-nerolidol (6.9%).

Evolutionary control of leaf element composition in plants

Leaf nitrogen (N) and phosphorus (P) concentrations are correlated in plants. Higher-level phylogenetic effects can influence leaf N and P. By contrast, little is known about the phylogenetic variation in the leaf accumulation of most other elements in plant tissues, including elements with quantitatively lesser roles in metabolism than N, and elements that are nonessential for plant growth. Here the leaf composition of 42 elements is reported from a statistically unstructured data set comprising over 2000 leaf samples, representing 670 species and 138 families of terrestrial plants. Over 25% of the total variation in leaf element composition could be assigned to the family level and above for 21 of these elements. The remaining variation corresponded to differences between species within families, to differences between sites which were likely to be caused by soil and climatic factors, and to variation caused by sampling techniques. While the majority of variation in leaf mineral composition is undoubtedly associated with nonevolutionary factors, identifying higher-level phylogenetic variation in leaf elemental composition increases our understanding of terrestrial nutrient cycles and the transfer of toxic elements from soils to living organisms. Identifying mechanisms by which different plant families control their leaf elemental concentration remains a challenge.

Geochemistry and petrology of Mesozoic-Cenozoic magmatic complexes of the southern framing of the Aldan shield: Geodynamic problems

This paper summarizes the results of long-term geological, petrological, and geochemical investigations of the Mesozoic-Cenozoic complexes of the Stanovoy Range in order to determine the main reasons for their generation and evolution. The analysis of this material showed that the compositionally variable Late Mesozoic igneous complexes of the Stanovoy Range were formed in various depth facies, from abyssal to surficial. The majority of their salic complexes show minor compositional variations, whereas the mafic complexes are more variable, especially in the southeast of the region. The southeastern Stanovoy Range comprises comparable amounts of both subalkaline and low-alkali igneous rocks, whereas the central part is dominated by subalkaline rocks, and the northwestern part contains rocks only of the shoshonite-latite series. This zoning is fundamentally different from that of typical island arcs, which are characterized by the occurrence of volcanic rocks of similar alkalinity in each zone. Extrusive and intrusive rocks with similar alkali and silica contents (and schlieren-like inclusions in the granitoids of the region) were formed from common magmas of corresponding chemical compositions. In addition, the mafic and most of the salic magmas were formed as independent melting products, whereas the magmas of intermediate composition were formed mainly by mixing of chemically contrasting liquids (i.e., salic and basic). It was shown that the available information on the magmatism of the region is best interpreted in terms of the model of mantle diapirism. In particular, mantle diapirs ascended rather slowly during the Mesozoic and occurred over the whole territory of the Stanovoy Range during the Jurassic-Cretaceous stage (J3-K1), when alkaline and subalkaline basalts were formed. During the Early-Late Cretaceous stage, mantle diapirs produced alkali-poor basalts in the central and eastern parts. During the Cenozoic, the diapir ascended rather rapidly but only in a small area in the eastern part of the region forming alkali basalts. In contrast to the Cenozoic, the Earth’s crust was strongly affected by mantle diapirs and related mafic magmas in the Mesozoic. As a result, crustal sequences were reworked by fluids and subsequently yielded tremendous volumes of compositionally corresponding salic magmas, which interacted and mixed with mafic magmas producing the corresponding chemical zoning. The maximum generation of crustal magmas was confined to the axial zones of ascending diapirs, where the highest energy effects took place, whereas the role of autochthonous gneissic granites increased away from the axis at the expense of typical intrusive complexes.

Depth-wise variation of physical and mechanical properties of mudstone in relation to weathering

In order to study the physical and chemical weathering and their impact on the shear strength of the soil mass, soil samples were collected from different depths ranging from the ground surface to a depth of 15m at two different drainage wells in a Mukohidehara landslide area. These specimens represent the residual soil near the surface, specimen at a depth range of ground water level fluctuation, less weathered specimen from the depth below the ground water level fluctuation, the remolded soil from sliding zone and the specimen below sliding zone. Measurement of Atterberg's limits, particle size analysis, X-ray diffraction analysis, slake durability test and X-ray fluorescence tests were carried out. Drained simple shear tests, and drained ring shear tests were also conducted on those specimens to measure their strength characteristics.Test results showed that fully softened shear strength of the less weathered specimen was very close to the peak shear strength of the specimen from the sliding zone. Test results showed no significant variations of index properties (liquid limit, plasticity index and clay fraction) , mineral compositions and chemical compositions with depth. Residual shear strengths of the specimen also did not vary much with depth. In order to compare these findings with rocks from the other types of formation, specimens were collected from the ground surface, ground water fluctuation zone, less weathered zone and sliding zone of three other landslides sites. The test results on the index properties, shear strength properties, mineralogical analysis, and bulk chemistry, of those landslides were consistent with the findings in Mukohidehara landslide.The test results of this study suggested that physical weathering plays a major role in the reduction of shear strength of mudstone, in comparison to the chemical weathering in the form of mineralogical and chemical alteration. Test results also suggested that physical weathering by slaking and disintegration is significant at ground water fluctuation zone in those mudstone formations.

Palaeoenvironmental changes at the Frasnian/Famennian boundary in key European sections: Chemostratigraphic constraints

The study aims to put constraints on global environmental changes, which took place during the Frasnian–Famennian (F/F) transition by using a geochemical multiproxy approach. For this several key European F/F boundary sections deposited in different palaeogeographic settings were selected, including, in addition to the stratotype and parastratotype sections of Coumiac (Montagne Noire, France) and Steinbruch Schmidt/Branau (Germany), respectively, also, some other sections thoroughly characterized by other authors (the drilling Büdesheimer Bach/Prümer Mulde, Germany; Kowala Section, Holy Cross Mountains, Poland; La Serre, France). Changes in the detrital flux along the sections were evaluated on the basis of both variations in mineral composition and in some diagnostic element ratios like Ti/Al. The biogenic flux was assessed as a function of the C org content. The input of nutrients or the palaeoproductivity was determined by the P 2O 5 and Ba in excess. The degree of anoxia during deposition was constrained by determining the concentration of redox sensitive metals (e.g., Fe, Mn) in the bulk sediment, of specific element ratios (e.g., V/Cr), as well as the size of pyrite grains together with the degree of pyritization (DOP) in the Büdesheimer Bach core. The hydrothermal and volcanic influence in the sedimentary record was detected using, e.g., the Al/(Al + Fe + Mn) and Zr/Al 2O 3 ratios. The Kellwasser horizons are characterized by a general decrease in the detrital input together with the increase of Al-normalized concentration of some of the transition metals. These changes are interpreted as reflecting a relative sea-level rise and a higher hydrothermal influence. In contrast to these, the establishment of dysoxic/anoxic conditions in the depositional environment as well as the increase of organic matter burial are not always restricted to the Kellwasser horizons (KWH). Moreover, the hydrothermal influence can lead to misinterpretation with respect to redox conditions and productivity due to the additional input of some specific elements. Our results indicate the coincidence of sea-level rise with hydrothermalism and volcanism during the deposition of the KWH in the area of South Laurussia and North Gondwana. The resulting enrichment in metals and nutrients is coupled in several F/F boundary sections with a higher microbial activity, as already observed by some authors. These effects coupled with a general lowering of the degree of oxygenation of the water bodies could have played a significant role in the demise of the biota.

Characteristics of subcontinental lithospheric mantle beneath Baegryeong Island, Korea: Spinel peridotite xenoliths

Abstract Geochemical data on Baegryeong Island spinel peridotites found in Miocene alkali basalt provide the information for lithosphere composition, chemical processes, equilibrium pressure and temperature conditions. Spinel peridotite xenoliths, showing transitional textures between protogranular and porpyroclastic textures, were accidentally trapped by the ascending alkali basalt magma. The xenoliths originate at depths from 50 to 70 km with a temperature range from 800 to 1100°C. The variations of modal and mineral compositions of the spinel peridotite xenoliths indicate that the xenoliths have undergone 1–10% fractional melting. The spinel peridotites from Baegryeong Island have undergone cryptic mantle metasomatism subsequent to melt extraction. Metasomatic agent of enriched spinel peridotite xenoliths was carbonatite melt.

A single-particle characterization of a mobile Versatile Aerosol Concentration Enrichment System for exposure studies

BackgroundAn Aerosol Time-of-Flight Mass Spectrometer (ATOFMS) was used to investigate the size and chemical composition of fine concentrated ambient particles (CAPs) in the size range 0.2–2.6 μm produced by a Versatile Aerosol Concentration Enrichment System (VACES) contained within the Mobile Ambient Particle Concentrator Exposure Laboratory (MAPCEL). The data were collected during a study of human exposure to CAPs, in Edinburgh (UK), in February-March 2004. The air flow prior to, and post, concentration in the VACES was sampled in turn into the ATOFMS, which provides simultaneous size and positive and negative mass spectral data on individual fine particles.ResultsThe particle size distribution was unaltered by the concentrator over the size range 0.2–2.6 μm, with an average enrichment factor during this study of ~5 (after dilution of the final air stream). The mass spectra from single particles were objectively grouped into 20 clusters using the multivariate K-means algorithm and then further grouped manually, according to similarity in composition and time sequence, into 8 main clusters. The particle ensemble was dominated by pure and reacted sea salt and other coarse inorganic dusts (as a consequence of the prevailing maritime-source climatology during the study), with relatively minor contributions from carbonaceous and secondary material. Very minor variations in particle composition were noted pre- and post-particle concentration, but overall there was no evidence of any significant change in particle composition.ConclusionThese results confirm, via single particle analysis, the preservation of the size distribution and chemical composition of fine ambient PM in the size range 0.2–2.6 μm after passage through the VACES concentration instrumentation.

Methane yield in source-sorted organic fraction of municipal solid waste

Treating the source-separated organic fraction of municipal solid waste (SS-OFMSW) by anaerobic digestion is considered by many municipalities in Europe as an environmentally friendly means of treating organic waste and simultaneously producing methane gas. Methane yield can be used as a parameter for evaluation of the many different systems that exist for sorting and pre-treating waste. Methane yield from the thermophilic pilot scale digestion of 17 types of domestically SS-OFMSW originating from seven full-scale sorting systems was found. The samples were collected during 1 year using worked-out procedures tested statistically to ensure representative samples. Each waste type was identified by its origin and by pre-sorting, collection and pre-treatment methods. In addition to the pilot scale digestion, all samples were examined by chemical analyses and methane potential measurements. A VS-degradation rate of around 80% and a methane yield of 300–400 Nm 3 CH 4/ton VS in were achieved with a retention time of 15 days, corresponding to ∼70% of the methane potential. The different waste samples gave minor variation in chemical composition and thus also in methane yield and methane potential. This indicates that sorting and collection systems in the present study do not significantly affect the amount of methane produced per VS treated.

Effects of Fertilization, Crop Year, Variety, and Provenance Factors on Mineral Concentrations in Onions

Mineral concentrations of onions (Allium cepa L.) grown under various conditions, including factors (fertilization, crop year, variety, and provenance), were investigated to clarify how much each factor contributes to the variation of their concentrations. This was because the mineral concentrations might be affected by various factors. The ultimate goal of this study was to develop a technique to determine the geographic origins of onions by mineral composition. Samples were onions grown under various conditions at 52 fields in 18 farms in Hokkaido, Japan. Twenty-six elements (Li, Na, Mg, Al, P, K, Ca, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Y, Mo, Cd, Cs, Ba, La, Ce, Nd, Gd, W, and Tl) in these samples were determined by inductively coupled plasma atomic emission spectrometry and inductively coupled plasma mass spectrometry. Fertilization conditions and crop years of onions caused variations of P, Ni, Cu, Rb, Sr, Mo, Cs, and Tl concentrations in onions; different onion varieties also showed variations in numerous element concentrations. However, the variations of mineral compositions of onions by these factors were smaller than the differences between production places with a few exceptions. Furthermore, Na, Rb, and Cs in group IA of the periodic table, Ca, Sr, and Ba in group IIA, and Zn and Cd in group IIB showed similar concentration patterns by group; this result demonstrated that elements in the same periodic groups behaved similarly in terms of their absorption in onions.

Definition of Quality in Cast Aluminum Alloys and Its Characterization with Appropriate Indices

In this paper, the issue of “quality” of cast aluminum alloys from various viewpoints is interpreted. Many methods to characterize the quality of materials are available; the methods used currently for the quality evaluation of cast aluminum alloys include nondestructive testing, characterization of the microstructure, and mechanical testing. With regard to mechanical testing, a number of quality indices have been devised to evaluate and characterize the quality of cast aluminum alloys. As these quality indices use different mechanical properties for the quality evaluation, they are expected to lead to different results. In this work, the application of proposed quality indices and their suitability is discussed for a number of situations, including minor variations in chemical composition, different solidification rate, solid solution and artificial aging heat treatments.

Experimental constraints on ureilite petrogenesis

This experimental study explores the petrogenesis of ureilites by a partial melting/smelting process. Experiments have been performed over temperature (1150–1280 °C), pressure (5–12.5 MPa), and low oxygen fugacity (graphite–CO gas) conditions appropriate for a hypothetical ureilite parent body ∼200 km in size. Experimental and modeling results indicate that a partial melting/smelting model of ureilite petrogenesis can explain many of the unique characteristics displayed by this meteorite group. Compositional information preserved in the pigeonite–olivine ureilites was used to estimate the composition of melts in equilibrium with the ureilites. The results of 20 experiments saturated with olivine, pyroxene, metal, and liquid with appropriate ureilite compositions are used to calibrate the phase coefficients and pressure–temperature dependence of the smelting reaction. The calibrated coefficients are used to model the behavior of a hypothetical residue that is experiencing fractional smelting. The residue is initially olivine-rich and smelting progressively depletes the olivine content and enriches the pyroxene and metal contents of the residues. The modeled residue composition at 1260 °C best reproduces the trend of ureilite bulk compositions. The model results also indicate that as a ureilite residue undergoes isothermal decompression smelting over a range of temperatures, Ca/Al values and Cr 2O 3 contents are enriched at lower temperatures (below ∼1240 °C) and tend to decrease at higher temperatures. Therefore, fractional smelting can account for the high Ca/Al and Cr 2O 3 wt% values observed in ureilites. We propose that ureilites were generated from an olivine-rich, cpx-bearing residue. Smelting began when the residue was partially melted and contained liquid, olivine, and carbon. These residues experienced varying degrees of fractional smelting to produce the compositional variability observed within the pigeonite-bearing ureilites. Variations in mineral composition, modal proportions, and isotopic signatures are best described by heterogeneous accretion of the ureilite parent body followed by minimal and variable degrees of igneous processing.