13,435 research outputs found

    The investigation of heavy metal ion content in rock and coal production

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    Приведено олгляд методів визначення вмісту важких металів у вугіллі та продуктах вуглевидобутку. Виявлена доцільність використання НВЧ-поля та зниження температури озолення проб для підвищення точності визначення та зниження витрат часу на проведення аналізу.Приведен обзор методов определения тяжелых металлов в угле и продуктах угледобычи. Выявлена целесообразность использования СВЧ-поля и снижения температуры озоления проб для повышения точности определения и уменьшения затрат времени на проведения анализа.A review over the methods of heavy metals determination in coal and products of coal mining is present. Expediency of the use of microwave and declines of temperature for ash tests is educed for the exactness increase of determination and diminishing time for analysis

    Design and comparative analysis of single-path and epidemic approaches to information and energy management in wireless sensor networks

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    Intelligent energy management is a key challenge in Wireless Sensor Networks. The choice of an appropriate routing algorithm constitutes a critical factor, especially in unstructured networks where, due to their dynamic nature, a reactive routing protocol is necessary. Such networks often favour packet flooding to fulfil this need. One such algorithm is IDEALS, a technique proposed in the literature, which balances energy consumed with information delivered. This paper evaluates the use of a single-path solution with IDEALS to increase efficiency. Simulation results comparing the two approaches show that the single-path algorithm outperforms flooding in terms of energy consumption for any network size. Furthermore the benefit of IDEALS is preserved as its combination with the single-path algorithm maximises information throughput

    Modeling the Regional Economic Impacts of the 2007/08 Drought: Results and Lessons

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    The 2007-08 drought affected a large area of New Zealand. This paper describes the analytical framework used to estimate the associated regional and national economic impacts. Results suggest that calculating drought economic impacts by applying standard farming industry multipliers to changes in farm gate output can greatly overstate both regional and national economic impacts. Calculating impacts using differences between forecast and actual farm production and expenditure by farm type is both feasible and produces far more reliable impact estimates.Economic Impact, Drought, Modeling, Agricultural and Food Policy, Crop Production/Industries, Environmental Economics and Policy, Farm Management, Land Economics/Use,

    Synaptic Wnt/GSK3β Signaling Hub in Autism

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    Indexación: ScopusHundreds of genes have been associated with autism spectrum disorders (ASDs) and the interaction of weak and de novo variants derive from distinct autistic phenotypes thus making up the "spectrum." The convergence of these variants in networks of genes associated with synaptic function warrants the study of cell signaling pathways involved in the regulation of the synapse. The Wnt/β-catenin signaling pathway plays a central role in the development and regulation of the central nervous system and several genes belonging to the cascade have been genetically associated with ASDs. In the present paper, we review basic information regarding the role of Wnt/β-catenin signaling in excitatory/inhibitory balance (E/I balance) through the regulation of pre-and postsynaptic compartments. Furthermore, we integrate information supporting the role of the glycogen synthase kinase 3β (GSK3β) in the onset/development of ASDs through direct modulation of Wnt/β-catenin signaling. Finally, given GSK3β activity as key modulator of synaptic plasticity, we explore the potential of this kinase as a therapeutic target for ASD.https://www.hindawi.com/journals/np/2016/9603751

    Electrolyte and Water Balance of the Early Avian Embryo: Effects of Egg Turning

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    Formation of sub-embryonic fluid (SEF) is a key aspect of the physiology of the early avian embryo.Here we review the process of SEF formation and the factors which influence its composition and the rate of SEF production and depletion in the Japanese quail and domestic fowl.There is particular emphasis on the role of turning of the egg during incubation and we briefly consider the broader role of egg turning during avian incubation. The bulk of the review deals with the growth of the area vasculosa of the yolk sac membrane, the cellular processes of SEF formation, and the water and electrolyte physiology of the avian embryo during the first half of incubation.We conclude with a brief discussion of the areas for future investigation

    Variational study of the Holstein polaron

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    The paper deals with the ground and the first excited state of the polaron in the one dimensional Holstein model. Various variational methods are used to investigate both the weak coupling and strong coupling case, as well as the crossover regime between them. Two of the methods, which are presented here for the first time, introduce interesting elements to the understanding of the nature of the polaron. Reliable numerical evidence is found that, in the strong coupling regime, the ground and the first excited state of the self-trapped polaron are well described within the adiabatic limit. The lattice vibration modes associated with the self-trapped polarons are analyzed in detail, and the frequency softening of the vibration mode at the central site of the small polaron is estimated. It is shown that the first excited state of the system in the strong coupling regime corresponds to the excitation of the soft phonon mode within the polaron. In the crossover regime, the ground and the first excited state of the system can be approximated by the anticrossing of the self-trapped and the delocalized polaron state. In this way, the connection between the behavior of the ground and the first excited state is qualitatively explained.Comment: 11 pages, 4 figures, PRB 65, 14430

    A Chebyshev collocation method for solving two-phase flow stability problems

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    This paper describes a Chebyshev collocation method for solving the eigenvalue problem that governs the stability of parallel two-phase flow. The method is based on the expansion of the eigenfunctions in terms of Chebyshev polynomials, point collocation, and the subsequent solution of the resulting generalized eigenvalue problem with the QZ-algorithm. We concentrate on the question how to handle difficulties that arise when these ¿standard¿ techniques are applied to the stability problem of a thin film of liquid that is sheared by a gas. After discussing this specific problem in detail, it is argued that the method of solution can readily be applied to other two-phase flow configurations as well

    Genetic and functional characterization of the gene cluster directing the biosynthesis of putisolvin I and II in Pseudomonas putida strain PCL1445

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    Pseudomonas putida PCL1445 secretes two cyclic lipopeptides, putisolvin I and putisolvin II, which possess a surface-tension-reducing ability, and are able to inhibit biofilm formation and to break down biofilms of Pseudomonas species including Pseudomonas aeruginosa. The putisolvin synthetase gene cluster (pso) and its surrounding region were isolated, sequenced and characterized. Three genes, termed psoA, psoB and psoC, were identified and shown to be involved in putisolvin biosynthesis. The gene products encode the 12 modules responsible for the binding of the 12 amino acids of the putisolvin peptide moiety. Sequence data indicate that the adenylation domain of the 11th module prioritizes the recognition of Val instead of Leu or Ile and consequently favours putisolvin I production over putisolvin II. Detailed analysis of the thiolation domains suggests that the first nine modules recognize the D form of the amino acid residues while the two following modules recognize the L form and the last module the L or D form, indifferently. The psoR gene, which is located upstream of psoA, shows high similarity to luxR-type regulatory genes and is required for the expression of the pso cluster. In addition, two genes, macA and macB, located downstream of psoC were identified and shown to be involved in putisolvin production or export

    Microdisk Resonators with Two Point Scatterers

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    Optical microdisk resonators exhibit modes with extremely high Q-factors. Their low lasing thresholds make circular microresonators good candidates for the realization of miniature laser sources. They have, however, the serious drawback that their light emission is isotropic, which is inconvenient for many applications. In our previous work, we showed that the presence of a point scatterer inside the disk can lead to highly directional modes in various frequency ranges while preserving the high Q-factors. In the present paper we generalize this idea to two point scatterers. The motivation for this work is that the strength of a point scatterer is difficult to control in experiments, and the presence of a second scatterer leads to a higher dimensional parameter space which permits to compensate this deficiency. Similar to the case of a single scatterer in a circular disk, the problem of finding the resonance modes in the presence of two scatterers is to a large extent analytically tractable.
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