24,087 research outputs found

    Использование золошлаковых материалов теплоэнергетики в строительных материалах

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    The possible trends to improve the building-technical properties of dry ashes characteristics formed as a result of solid fuel combustion at thermal power stations are presented. The results of different fly-ash conditioning technologies application to widen the trends and to increase the volumes of their use in the construction materials and products.Представлены возможные направления улучшения строительно-технических характеристик сухих зол, образующихся при сжигании твердого топлива на тепловых электростанциях. Приведены результаты применения различных технологий кондиционирования свойств золы для расширения направлений и увеличения объемов их использования при производстве строительных материалов и изделий

    Tephrochronology: principles, functioning, application

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    Tephrochronology is a unique method for linking and dating geological, palaeoecological, palaeoclimatic or archaeological sequences or events. The method relies firstly and fundamentally on stratigraphy and the law of superposition, which apply in any study that connects or correlates deposits from one place to another. Secondly, it relies on characterising and hence identifying or „fingerprinting‟ tephra layers using either physical properties evident in the field or those obtained from laboratory analysis, including mineralogical examination by optical microscopy or geochemical analysis of glass shards or crystals (e.g., Fe-Ti oxides, ferromagnesian minerals) using the electron microprobe and other tools. Thirdly, the method is enhanced when a numerical age is obtained for a tephra layer by (1) radiometric methods such as radiocarbon, fission-track, U-series, or Ar/Ar dating, (2) incremental dating methods including dendrochronology or varved sediments or layering in ice cores, or (3) age-equivalent methods such as palaeomagnetism or correlation with marine oxygen isotope stages or palynostratigraphy. Once known, that age can be transferred from one site to the next using stratigraphic methods and by matching compositional characteristics, i.e., comparing ‘fingerprints’ from each layer. Used this way, tephrochronology is an age-equivalent dating method

    Formation scenarios and mass-radius relation for neutron stars

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    Neutron star crust, formed via accretion of matter from a companion in a low-mass X-ray binary (LMXB), has an equation of state (EOS) stiffer than that of catalyzed matter. At a given neutron star mass, M, the radius of a star with an accreted crust is therefore larger, by DR(M), than for usually considered star built of catalyzed matter. Using a compressible liquid drop model of nuclei, we calculate, within the one-component plasma approximation, the EOSs corresponding to different nuclear compositions of ashes of X-ray bursts in LMXB. These EOSs are then applied for studying the effect of different formation scenarios on the neutron-star mass-radius relation. Assuming the SLy EOS for neutron star's liquid core, derived by Douchin & Haensel (2001), we find that at M=1.4 M_sun the star with accreted crust has a radius more than 100 m larger that for the crust of catalyzed matter. Using smallness of the crust mass compared to M, we derive a formula that relates DR(M) to the difference in the crust EOS. This very precise formula gives also analytic dependence of DR on M and R of the reference star built of catalyzed matter. The formula is valid for any EOS of the liquid core. Rotation of neutron star makes DR(M) larger. We derive an approximate but very precise formula that gives difference in equatorial radii, DR_eq(M), as a function of stellar rotation frequency.Comment: 6 pages, 4 figures. Accepted for publication in Astronomy and Astrophysic

    Connecting with tephras: principles, functioning, and applications of tephrochronology in Quaternary science

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    Tephrochronology is a unique method for linking and dating geological, palaeoecological, palaeoclimatic, or archaeological sequences or events. The method relies firstly on stratigraphy and the law of superposition, which apply in any study that connects or correlates deposits from one place to another. Secondly, it relies on characterising and hence identifying or ‘fingerprinting’ tephra layers using either physical properties evident in the field or those obtained from laboratory analysis, including mineralogical examination by optical microscopy or geochemical analysis of glass shards or crystals (e.g., Fe-Ti oxides, ferromagnesian minerals) using the electron microprobe and other tools. Thirdly, the method is enhanced when a numerical age is obtained for a tephra layer by (1) radiometric methods such as radiocarbon, fission-track, U-series, or Ar/Ar dating, (2) incremental dating methods including dendrochronology or varved sediments or layering in ice cores, or (3) age-equivalent methods such as palaeomagnetism or correlation with marine oxygen isotope stages or palynostratigraphy. Once known, that age can be transferred from one site to the next using stratigraphic methods and by matching compositional characteristics, i.e., comparing ‘fingerprints’ from each layer. Used this way, tephrochronology is an age-equivalent dating method

    Connecting and dating with tephras: principles, functioning, and application of tephrochronology in Quaternary research

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    Tephrochronology, the characterisation and use of volcanic-ash layers as a unique chronostratigraphic linking, synchronizing, and dating tool, has become a globally-practised discipline of immense practical value in a wide range of subjects including Quaternary stratigraphy, palaeoclimatology, palaeoecology, palaeolimnology, physical geography, geomorphology, volcanology, geochronology, archaeology, human evolution, anthropology, and human disease and medicine. The advent of systematic studies of cryptotephras – the identification, correlation, and dating of sparse, fine-grained glass-shard concentrations ‘hidden’ within sediments or soils – over the past ~20 years has been revolutionary. New cryptotephra techniques developed in northwestern Europe and Scandinavia in particular and in North America most recently adapted or improved to help solve problems as they arose, have now been applied to sedimentary sequences (including ice) on all the continents. The result has been the extension of tephra isochrons over wide areas hundreds to several thousands of kilometres from source volcanoes. Taphonomic and other issues, such as quantifying uncertainties in correlation, provide scope for future work. Developments in dating and analytical methods have led to important advances in the application of tephrochronology in recent times. In particular: (i) the ITPFT (glass fission-track) method has enabled landscapes and sequences to be dated where previously no dates were obtainable or where dating was problematic; (ii) new EMPA protocols enabling narrow-beam analyses (<5 um) of glass shards, or small melt inclusions, have been developed, meaning that small (typically distal) glass shards or melt inclusions <~10 um in diameter can now be analysed more efficaciously than previously (and with reduced risk of accidentally including microlites in the analysis as could occur with wide-beam analyses); (iii) LA-ICPMS method for trace element analysis of individual shards <~10 um in diameter is generating more detailed ‘fingerprints’ for enhancing tephra-correlation efficacy (Pearce et al., 2011, 2014; Pearce, 2014); and (iv) the revolutionary rise of Bayesian probability age modelling has helped to improve age frameworks for tephras of the late-glacial to Holocene period especially

    My boy builds coffins. Future memories of your loved ones

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    The research is focus on the concept of storytelling associated with product design, trying to investigate new ways of designing and a possible future scenario related to the concept of death. MY BOY BUILDS COFFINS is a gravestone made using a combination of cremation’s ashes and resin. It is composed by a series of holes in which the user can stitch a text, in order to remember the loved one. The stitching need of a particular yarn produced in Switzerland using some parts of human body. Project also provides another version which uses LED lights instead of the yarn. The LEDs - thanks to an inductive coupling - will light when It will be posed in the hole. The gravestone can be placed where you want, as if it would create a little altar staff at home. In this way, there is a real connection between the user and the dearly departed

    Quark-Novae in Low-mass X-ray Binaries II: Application to G87-7 and to GRB 110328A

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    We propose a simple model explaining two outstanding astrophysical problems related to compact objects: (1) that of stars such as G87-7 (alias EG 50) that constitute a class of relatively low-mass white dwarfs which nevertheless fall away from the C/O composition and (2) that of GRB 110328A/Swift J164449.3+57345 which showed spectacularly long-lived strong X-ray flaring, posing a challenge to standard GRB models. We argue that both these observations may have an explanation within the unified framework of a Quark-Nova occurring in a low-mass X-ray binary (neutron star- white dwarf). For LMXBs where the binary separation is sufficiently tight, ejecta from the exploding Neutron Star triggers nuclear burning in the white dwarf on impact, possibly leading to Fe-rich composition compact white dwarfs with mass 0.43M_sun < M_WD < 0.72M_sun, reminiscent of G87-7. Our results rely on the assumption, which ultimately needs to be tested by hydrodynamic and nucleosynthesis simulations, that under certain circumstances the WD can avoid the thermonuclear runaway. For heavier white dwarfs (i.e. M_WD > 0.72M_sun) experiencing the QN shock, degeneracy will not be lifted when Carbon burning begins, and a sub-Chandrasekhar Type Ia Supernovae may result in our model. Under slightly different conditions, and for pure He white dwarfs (i.e. M_WD < 0.43M_sun), the white dwarf is ablated and its ashes raining down on the Quark star leads to accretion-driven X-ray luminosity with energetics and duration reminiscent of GRB 110328A. We predict additional flaring activity towards the end of the accretion phase if the Quark star turns into a Black Hole.Comment: Accepted for publication in ApJ. Extended paper size to 6 journal pages (from 4). Table is extended and more detailed. Related animations at: http://quarknova.ucalgary.ca/media/ (find paper I of the series here: http://adsabs.harvard.edu/abs/2011ApJ...729...60O

    OxyCAP UK: Oxyfuel Combustion - academic Programme for the UK

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    The OxyCAP-UK (Oxyfuel Combustion - Academic Programme for the UK) programme was a £2 M collaboration involving researchers from seven UK universities, supported by E.On and the Engineering and Physical Sciences Research Council. The programme, which ran from November 2009 to July 2014, has successfully completed a broad range of activities related to development of oxyfuel power plants. This paper provides an overview of key findings arising from the programme. It covers development of UK research pilot test facilities for oxyfuel applications; 2-D and 3-D flame imaging systems for monitoring, analysis and diagnostics; fuel characterisation of biomass and coal for oxyfuel combustion applications; ash transformation/deposition in oxyfuel combustion systems; materials and corrosion in oxyfuel combustion systems; and development of advanced simulation based on CFD modelling

    Towards a breakthrough in nutrient recycling : State-of-the-art and recommendations for developing policy instruments in Finland

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    The report has been complemented on 11.9.2018This report describes the state-of-the-art in phosphorus and nitrogen recycling in Finland and looks at basic data on the volumes and geographical distribution of biomasses and their nutrients. Based on this data, the report makes proposals for measures aiming to promote nutrient recycling. This report was prepared collaboratively by experts at the institutions making up the Finnish Partnership for Research on Natural Resources and the Environment (LYNET) to underpin a national action plan on nutrient recycling. Of all sectors in Finland, agriculture is the largest user and recycler of phosphorus and nitrogen. Different biomasses contain an annual total of approximately 26,000 t of recyclable phosphorus, which exceeds the fertilisation needs of grasslands and cereal crops in the entire area of Finland. The volume of nitrogen contained in biomasses is approximately 95,000 t. Still, approx. 11,000 t of phosphorus and 152,000 t of nitrogen are annually used in Finland as conventional inorganic fertilisers. There is a regional imbalance between manure production and crop nutrient requirements. The breakthrough in nutrient recycling means increased implementation of manure processing, thus making manure nutrients easier to transport and reducing the use of conventional inorganic fertilisers. At minimum 20% of the entire volume of manure generated in Finland will require advanced processing to enable long-distance transport of the manure phosphorus to areas in need of it. This requires separation of water. The highest demand for advanced processing is experienced in the regions of Ostrobothnia (approx. 60% at minimum), South Ostrobothnia and Satakunta (approx. 30 %) and Southwest Finland (13%). In the agricultural sector, fertilisation is currently guided by a wide array of different policy instruments, which make up an incoherent and unstructured whole. The instruments cause considerable amounts of regulatory burden, but appear to do little to promote sustainable nutrient recycling. This report proposes a total reform of the policy instruments to boost the recycling of nutrients. All legal standards related to fertilisation should be merged into a single statute, for example by developing the Nitrate Decree. At the same time, the current policy that controls nutrient use via the EU agri-environmental scheme should be abandoned, and the role of the environmental permit for livestock installations and its relationship with general regulatory instruments be clarified. A field plot specific nutrient database should be created to support guidance. The knowledge base of nutrient recycling should be developed by creating and maintaining a comprehensive data system on the quantities, properties and locations of nutrient-rich biomasses and ashes and their current processing methods. The report also proposes setting regional processing targets for livestock manure. Key objectives should include reducing excessive fertilisation in crop production. The goal of normative guidance should be nutrient use according to the crop needs.201
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