31 research outputs found

    Peshtasar basalts: An example of post-collision basalts in sedimentary Basin of Moghan, NW Iran

    Get PDF
    With an east–west exposure trend, Peshtasar Complex, which is located in the sedimentary basin of Moghan, northwestern Iran, is lithologically varied. The main constituent minerals are plagioclase, clinopyroxene and iddingsitised olivine in basalts and plagioclase megacryst, clinopyroxene and leucite in tephrite. The studied rocks are plotted in the fields of basaltic trachy-andesite, trachy-andesite and tephri-phonolite in the total alkali-silica (TAS) diagram as well as high-K to calc-alkaline and shoshonite fields. The chondrite normalised pattern of rare earth elements indicates the enrichment of LILE and LREE as well as the depletion of HFSE and HREE. Nb and Ti have a negative anomaly in the spider diagram. Eu/Eu* represents a positive anomaly for Eu indicating the frequency of calcic plagioclase and low oxygen fugacity in rocks. Geochemical parameters and diagrams predict a magmatic evolution via assimilation – fractional crystallisation process. According to the Ce/Yb vs. Ce diagram, partial melting has happened within the garnet–lherzolite field in the depth of ∼100 km. Based on 87Sr/86Sr, Shahyourdi samples have EM1 sources, whereas Germi and Tazehkand basalts have EM11 sources that are indicative of different mantle sources for basalts in the western Moghan of the central and eastern areas. Basalts are found in active continental margins associated with the post-collision arcs.publishe

    Mineralogy, mineral chemistry and thermobarometry of post-mineralization dykes of the Sungun Cu-Mo porphyry deposit (Northwest Iran)

    Get PDF
    The Sungun copper–molybdenum porphyry deposit is located in the north of Varzaghan, northwestern Iran. The Sungun quartz-monzonite is the oldest mineralized intrusive body in the region and was emplaced during the Early Miocene. Eight categories of the late and unmineralized dykes, which include quartz diorite, gabbrodiorite, diorite, dacite, microdiorite and lamprophyre (LAM), intrude the ore deposit. The main mineral phases in the dykes include plagioclase, amphibole and biotite, with minor quartz and apatite and secondary chlorite, epidote, muscovite and sericite. The composition of plagioclase in the quartz diorite dykes (DK1a, DK1b and DK1c) varies from albite-oligoclase to andesine and oligoclase to andesine; in the diorite, it varies from andesine to labradorite; in the LAM, from albite to oligoclase; and in the microdiorite (MDI), it occurs as albite. Amphibole compositions are consistent with classification as hornblende or calcic amphibole. Based on their AlIV value (less than 1.5), amphibole compositions are consistent with an active continental margin affinity. The average percentage of pistacite (P s) in epidotes formed from alteration of plagioclase and ferromagnesian minerals is 27–23% and 25–30%, respectively. Thermobarometric studies based on amphibole and biotite indicate approximate dyke crystallization temperature of 850–750℃, pressure of 231–336 MPa and high fO2 (>nickel-nickel-oxide buffer). The range of mineral compositions in the postmineralization dyke suite is consistent with a genetic relationship with the subduction of the Neotethys oceanic crust beneath the continental crust of the northwest part of the Central Iranian Structural Zone. Despite the change from calc-alkaline to alkaline magmatism, the dykes are likely related to the late stages of magmatic activity in the subduction system that also generated the porphyry deposit.publishe

    Prevalence of Helicobacter pylori infection and associated factors among adults in Southern Brazil: a population-based cross-sectional study

    Get PDF
    BACKGROUND: Helicobacter pylori (Hp) infection is associated with several upper gastrointestinal disorders. Local data on the epidemiology of the infection are scarce in Brazil. The purpose of this study is to measure the prevalence rate and to explore the associated factors among the adult population living in Pelotas, a southern Brazilin city. METHODS: This was a population-based cross-sectional study. Through a multi-stage sampling method all individuals 20 years and over living at the selected households at the urban area of the city were interviewed regarding past and current socio-economic indicators; demographic characteristics; nutritional and behavioural habits; and history of upper gastrointestinal symptoms.Hp infection was ascertained through the (13)C-UBT. Due to the high prevalence, data were analysed through robust Poisson regression. All analyses took into account the family clustering of the data. RESULTS: Among 563 eligible individuals, 363 agreed to perform the (13)C-UBT (refusal rate of 35.5%). Refusals were associated with female sex, consumption of mate drinking, and presence of upper gastrointestinal symptoms. The prevalence rate of H. pylori infection was 63.4% (95%CI 59.3%–69.3%). In crude analyses, prevalence was associated with increasing age, non-white skin colour, lower current family income, lower education level, higher size of the family, low socio-economic conditions in childhood, higher number of siblings and attendance to day-care centres in childhood, and presence of dyspeptic symptoms. In adjusted analysis the level of education of the father was inversely associated with the infection, whereas number of siblings and attendance to day-care centre in childhood were directly associated with it. Non-white skin colour remained significantly associated with increased prevalence even after allowing for past and current socio-economic characteristics, age and sex. Compared to non-symptomatic individuals, those reporting dyspeptic symptoms presented a higher prevalence of the infection even after allowing for current and past socio-economic conditions, ethnicity, age, and sex. CONCLUSION: Hp infection is as common among adults in southern Brazil as it is in other developing countries. Socio-economic conditions in childhood besides ethnicity and presence of dyspeptic symptoms were the factors significantly associated with the infection

    Electrostatic charging of jumping droplets

    Get PDF
    With the broad interest in and development of superhydrophobic surfaces for self-cleaning, condensation heat transfer enhancement and anti-icing applications, more detailed insights on droplet interactions on these surfaces have emerged. Specifically, when two droplets coalesce, they can spontaneously jump away from a superhydrophobic surface due to the release of excess surface energy. Here we show that jumping droplets gain a net positive charge that causes them to repel each other mid-flight. We used electric fields to quantify the charge on the droplets and identified the mechanism for the charge accumulation, which is associated with the formation of the electric double layer at the droplet–surface interface. The observation of droplet charge accumulation provides insight into jumping droplet physics as well as processes involving charged liquid droplets. Furthermore, this work is a starting point for more advanced approaches for enhancing jumping droplet surface performance by using external electric fields to control droplet jumping.United States. Dept. of Energy. Office of Basic Energy Sciences (Solid-State Solar-Thermal Energy Conversion Center Award DE-FG02-09ER46577)United States. Office of Naval ResearchNational Science Foundation (U.S.) (Major Research Instrumentation Grant for Rapid Response Research (MRI- RAPID))National Science Foundation (U.S.) (Award ECS-0335765)National Science Foundation (U.S.). Graduate Research Fellowship Program (Grant 1122374

    Is living near healthier food stores associated with better food intake in regional Australia?

    Get PDF
    High prevalence of obesity and non-communicable diseases is a global public health problem, in which the quality of food environments is thought to play an important role. Current scientific evidence is not consistent regarding the impact of food environments on diet. The relationship between local food environments and diet quality was assessed across 10 Australian suburbs, using Australian-based indices devised to measure the two parameters. Data of dietary habits from the participants was gathered using a short questionnaire. The suburbs’ Food Environment Score (higher being healthier) was associated with higher consumption of fruit (χ2 (40, 230) = 58.8, p = 0.04), and vegetables (χ2 (40, 230) = 81.3, p = 0.03). The Food Environment Score identified a significant positive correlation with four of the diet scores: individual total diet score (rs = 0.30, p \u3c 0.01), fruit and vegetable score (rs = 0.43, p \u3c 0.01), sugary drink score (rs = 0.13, p \u3c 0.05), and discretionary food score (rs = 0.15, p \u3c 0.05). Moreover, the suburbs’ RFEI (Retail Food Environment Index, higher being unhealthier) showed a significant association with higher consumption of salty snacks (χ2 (24, 230) = 43.9, p = 0.04). Food environments dominated by food outlets considered as ‘healthier’ were associated with healthier population food intakes, as indicated by a higher consumption of fruit, vegetables, and water, as well as a lower consumption of junk food, salty snacks, and sugary drinks. This association suggests that healthier diet quality is associated with healthier food environments in regional Australia

    Orthogonality for a class of generalised Jacobi polynomial Pνα,β(x)P^{\alpha,\beta}_{\nu}(x)

    Get PDF
    This work considers g-Jacobi polynomials, a fractional generalisation of the classical Jacobi polynomials. We discuss the polynomials and compare some of their properties to the classical case. The main result of the paper is to show that one can derive an orthogonality property for a sub-class of g-Jacobi polynomials Pνα,β(x)P^{\alpha,\beta}_{\nu}(x) The paper concludes with an application in modelling of ophthalmic surfaces

    Evaluation of a \u27healthiness\u27 rating system for food outlet types in Australian residential communities

    No full text
    Aim To obtain expert consensus to develop and evaluate a rating system on the relative healthiness of Australian suburbs’ food outlet types. Methods Twenty-four food outlet types and 10 local suburbs were identified from previous mapping studies and based on a scan of suburbs across one large Australian geographical region. Initial food outlet ‘scores’ for relative healthiness were proposed based on available literature, classified into five categories, from ‘most’ to ‘least’ healthy. In round 1 of a modified Delphi survey, participants, Australian public health and nutrition experts, were given each outlet type\u27s definition and the proposed scores and invited to modify the scores based on their perceived ‘healthiness’. In round 2, participants were able to revise or adjust their scores. Results Median scores for food outlet types from both rounds highly correlated with the originally proposed scores (two-tailed Pearson\u27s correlation coefficient 0.97 and 0.96, respectively, P = 0.01), and scores from round 1 highly correlated with those from round 2 (Pearson\u27s coefficient 0.998, P = 0.01). Round 2 scores were used to calculate suburbs’ overall food environment score, healthiness score, unhealthiness score and a ratio of unhealthiness to healthiness scores. There was strong positive correlation between suburbs’ ratio of unhealthiness to healthiness scores and a previously recognised scoring ratio, Retail Food Environment Index (Spearman\u27s rho 0.847, P \u3c 0.01). Conclusions The study generated experts’ consensus about relative healthiness of food outlet types found in Australian neighbourhoods. Proposed scores can be used to assess and compare healthiness of community food environments and to explore their associations with area characteristics, population\u27s diet and health outcomes

    Mineralogy and Mineral Chemistry of Dioritic Dykes, Quartz Diorite Enclaves and Pyroxene of the Sungun Cu-Mo Porphyry Deposit, East Azerbaijan, Iran

    No full text
    The Sungun Cu-Mo porphyry deposit forms part of the Ahar–Arasbaran Magmatic Belt (AAMB). Its host Miocene porphyry stock is quartz monzonitic in composition and is cut by intermediate dykes that post-date mineralization. These dykes contain pyroxene and enclaves of ambiguous origin. Dykes of microdiorite are observed within quartz diorite dykes, whereas later diorite dykes contain three different kinds of enclaves (diorite, quartz diorite and hornfels) of sizes between 1 and 10 cm. Enclaves consist of plagioclase, hornblende and biotite, with accessory sphene, quartz and apatite. Chlorite compositions in microdiorite are within the chamosite range, whereas they are within the clinochlore range in diorite enclaves. Microprobe analyses of pyroxene indicate an augitic composition (Fs13.38-22.79Wo29.1-33.57En48.53-56.61), consistent with an igneous origin. Hornblende of the diorite enclaves formed at pressures ranging between 3 and 5.3 kilobars and temperatures between 714 and 731 °C. Average oxygen fugacity during rock formation is −14.75. Such high oxygen fugacities suggest that the diorite formed near the boundaries of a convergent margin. Amphibole compositions suggest that the diorite enclaves are sub-alkaline to mildly alkaline, consistent with reported whole-rock chemistry of the Sungun magmas. Pyroxenes were formed at pressures ranging between 11 and 15 kilobars (33–45 km) and temperatures between 1100 and 1400 °C. The amount of Fe3+ in clinopyroxene is also consistent with high oxygen fugacity within their environment of crystallization. Overall, these results have implications for our understanding of the origin of the Sungun Cu-Mo porphyry magmas and their mineral deposits in a lower-crustal setting
    corecore