153 research outputs found

    On the finite-volume Lattice Boltzmann modeling of thermo-hydrodynamics

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    AbstractIn this paper, Thermal Finite-Volume Lattice Boltzmann Method is developed. To demonstrate the temperature field, the Double Distribution Function (DDF) of thermal lattice Boltzmann equation is used. The upwind biasing factors based on pressure and temperature are defined and applied as flux corrector in the thermo-hydrodynamic lattice Boltzmann equations. A consistent open and solid boundary treatment of flow is also addressed. The unknown energy distribution at the boundary cells are decomposed into its equilibrium and non-equilibrium parts. Then the non-equilibrium part is approximated with extrapolation of the non-equilibrium part of the populations at the neighboring nodes. This treatment enlarges the domain stability and led up to faster convergence. Two test cases namely, thermo-hydrodynamic in a backward-facing step and around a circular cylinder inserted within a backward-facing step are carried out. The results are compared with the available solutions in the technical literature

    Study on the growth status of mullets with viral nervous necrosis disease in the southern Caspian Sea

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    Mullet and mullet products have considerable economic importance at a regional level, especially around the Caspian Sea. The leaping mullet constitutes an important part of their production. This study is the first detailed work on the age and growth of the leaping mullet (Liza saliens) from September 2012 to March 2013 in the Southern coast of the Caspian Sea. Age and growth determinations were based upon the scale samples taken from 102 fish. Marginal increment analysis was used to validate age determination. The back-calculated lengths stage estimated from the scale showed no differences between in this study. The maximum age of leaping mullet in the Southern coast of the Caspian Sea was 5 years for males and 6 years for females. The von Bertalanffy growth functions were Lt=30.415(1-e-0.275(t+0.645)) for males and Lt=34.832(1-e 0.211(t+1.009)) for females. A large spread and length overlap characterized the age groups. The estimated Length Weight relationships were common for the two sexes (W=0.079L3 ). The slope (b) values of the length-weight relationship showed that weight of leaping grey mullet in Mazandaran increased associated with length in isometric. The mean condition factor for males, females and all specimens were determined as 0.908, 0.900 and 0.897, respectively. According to sex groups, the mean condition factor of males was slightlyhigher than that of females. The total length for leaping grey mullet was determined as 23.3 cm

    The survey statistical and biological of sturgeon in the southern Caspian Sea (Mazandaran waters)

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    This study have been conducted entitle biological and statistical sturgeon in the southern Caspian Sea (Mazandaran waters)” from 2009 to 2013. Sampling was manthly. Overal, 1859 specimens of different species of sturgeon was caught including Acipenserpersicus (69%), A. stellatus (19%), Husohuso (6%), A. nudiventris (4%) and A. guldenstaedtii (2%). Totally, the meat and caviar of five species were found 53263.6 kg and 5633 kg respectively and caviar to meat ratio was 10.6%. The results show that ration of meat and caviar whole species reduced from 2009 to 2012 in which the meat and caviar of A. persicus was declined from 12146 to 4465 kg in meat and caviar from 1358 to 487 kg were extremely reduced respectively. The CPUE (catch per unit effort) of sturgeon has fluctuated from 2009 to 2012. Totally, the CPUE of A. persicus was decreased from 0.150 (2009) to 0.130 (2012) kg boat per day, A. stellatue from 0.009 (2009) to 0.021 (2012) kg boat/day, A. guldenstaedtii from 0.002 (2009) to 0.003 (2012) kg boat/day, A. nudiventris from 0.027 (2009) to 0.001 (2012) kg boat/day and H. huso from 0.123 (2009) to 0.018 (2012) kg boat /day. 1061 specimens of fish has been caviar including A. persicus with 69%, A. stellatus (18.1%), H. huso (5.5%), A. guldenstaedtii (2.7%). The frequency of caviar categorize was included 1 , 2, 3 and massive with 49.6%, 38%), 10.6% and 1.9%, respectively. The highest of meat and caviar belong to A. persicus with 31414 kg and 3515.7 kg, respectively were found and the lowest was 841kg and 105.9 kg pertain to A. guldenstaedtii. The results show that 65.9% of sturgeon was caught by legal catch (landing) and 34.1% by beach seine remained. 391 individuals was age determined that the minimum and maximum age was 9 and 41 year comprised to H.huso and A. stellatus, respectively. A. persicus and A. stellatus were majority caught compare to other species. A. persicus has the highest frequency in 14-15 year age groups with 50% and 57% in 2009 and 2011, respectively and 15-16 year age group with 41% and 56% in 2010 and 2012, respectively. The results show that mean of fork length, body weight, caviar weight of A. persicus was declined because the FL and weight average (±SD) obtained from 152.4±16.7cm and 25.8±9.2 kg in 2009 to 146.5± 18.7cm and 22.1±9.2kg in 2012, respectively. In contrast, the average (±SD) FL and weight of H. huso was increased from 218.8±41.1cm and 137.3±96.6kg in 2009 to 231.3±45.2cm in FL and 146.2±78.5kg body weight in 2012, respectively. Consequently, the results show that stocks of sturgeon in the Caspian Sea has a trend declined because of some species in IUCN categorize list was Endangered in 2006 but at this moment lie in Critically Endangered list of IUCN categorize were down which could be a serious alarm for the valuable sturgeon fish in the Caspian Sea. Therefore, recommendation that trade catch of sturgeon in the Caspian Sea must be forbidden and continue legal catch for spawner fish that needede to artificial propagation only

    Biomarkers of Multiple Sclerosis

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    The search for an ideal multiple sclerosis biomarker with good diagnostic value, prognostic reference and an impact on clinical outcome has yet to be realized and is still ongoing. The aim of this review is to establish an overview of the frequent biomarkers for multiple sclerosis that exist to date. The review summarizes the results obtained from electronic databases, as well as thorough manual searches. In this review the sources and methods of biomarkers extraction are described; in addition to the description of each biomarker, determination of the prognostic, diagnostic, disease monitoring and treatment response values besides clinical impact they might possess. We divided the biomarkers into three categories according to the achievement method: laboratory markers, genetic-immunogenetic markers and imaging markers. We have found two biomarkers at the time being considered the gold standard for MS diagnostics. Unfortunately, there does not exist a single solitary marker being able to present reliable diagnostic value, prognostic value, high sensitivity and specificity as well as clinical impact. We need more studies to find the best biomarker for MS.publishersversionPeer reviewe

    Genome-wide association and Mendelian randomisation analysis provide insights into the pathogenesis of heart failure

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    Heart failure (HF) is a leading cause of morbidity and mortality worldwide. A small proportion of HF cases are attributable to monogenic cardiomyopathies and existing genome-wide association studies (GWAS) have yielded only limited insights, leaving the observed heritability of HF largely unexplained. We report results from a GWAS meta-analysis of HF comprising 47,309 cases and 930,014 controls. Twelve independent variants at 11 genomic loci are associated with HF, all of which demonstrate one or more associations with coronary artery disease (CAD), atrial fibrillation, or reduced left ventricular function, suggesting shared genetic aetiology. Functional analysis of non-CAD-associated loci implicate genes involved in cardiac development (MYOZ1, SYNPO2L), protein homoeostasis (BAG3), and cellular senescence (CDKN1A). Mendelian randomisation analysis supports causal roles for several HF risk factors, and demonstrates CAD-independent effects for atrial fibrillation, body mass index, and hypertension. These findings extend our knowledge of the pathways underlying HF and may inform new therapeutic strategies

    The fifth developing plan of Iranian Fisheries Research Institute

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    Accurate scientific and practical plan for achieving the goals of the Islamic Republic of Iran within the framework of Vision development 1404, is the infrastructure achieving sustainable development of the country. Order to achieve the above mentioned objectives and in order to the comprehensive development plans in the country, Iranian fisheries research organization adjust the fifth developing plan for support of executive related departments in country with mobilization a large number researchers consists of several working groups of ifro affiliated research centers. The fifth developing plan consist of three chapters for report of the forth developing plan and intrudction of research, construction plans and financial support (budjet) for period of 2011-2014 A.C

    Searches for lepton-flavour-violating decays of the Higgs boson in s=13\sqrt{s}=13 TeV pp\mathit{pp} collisions with the ATLAS detector

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    This Letter presents direct searches for lepton flavour violation in Higgs boson decays, H → eτ and H → μτ , performed with the ATLAS detector at the LHC. The searches are based on a data sample of proton–proton collisions at a centre-of-mass energy √s = 13 TeV, corresponding to an integrated luminosity of 36.1 fb−1. No significant excess is observed above the expected background from Standard Model processes. The observed (median expected) 95% confidence-level upper limits on the leptonflavour-violating branching ratios are 0.47% (0.34+0.13−0.10%) and 0.28% (0.37+0.14−0.10%) for H → eτ and H → μτ , respectively.publishedVersio

    Combination of searches for Higgs boson pairs in pp collisions at \sqrts = 13 TeV with the ATLAS detector

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    This letter presents a combination of searches for Higgs boson pair production using up to 36.1 fb(-1) of proton-proton collision data at a centre-of-mass energy root s = 13 TeV recorded with the ATLAS detector at the LHC. The combination is performed using six analyses searching for Higgs boson pairs decaying into the b (b) over barb (b) over bar, b (b) over barW(+)W(-), b (b) over bar tau(+)tau(-), W+W-W+W-, b (b) over bar gamma gamma and W+W-gamma gamma final states. Results are presented for non-resonant and resonant Higgs boson pair production modes. No statistically significant excess in data above the Standard Model predictions is found. The combined observed (expected) limit at 95% confidence level on the non-resonant Higgs boson pair production cross-section is 6.9 (10) times the predicted Standard Model cross-section. Limits are also set on the ratio (kappa(lambda)) of the Higgs boson self-coupling to its Standard Model value. This ratio is constrained at 95% confidence level in observation (expectation) to -5.0 &lt; kappa(lambda) &lt; 12.0 (-5.8 &lt; kappa(lambda) &lt; 12.0). In addition, limits are set on the production of narrow scalar resonances and spin-2 Kaluza-Klein Randall-Sundrum gravitons. Exclusion regions are also provided in the parameter space of the habemus Minimal Supersymmetric Standard Model and the Electroweak Singlet Model. For complete list of authors see http://dx.doi.org/10.1016/j.physletb.2019.135103</p

    Search for flavour-changing neutral currents in processes with one top quark and a photon using 81 fb⁻¹ of pp collisions at \sqrts = 13 TeV with the ATLAS experiment

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    A search for flavour-changing neutral current (FCNC) events via the coupling of a top quark, a photon, and an up or charm quark is presented using 81 fb−1 of proton–proton collision data taken at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC. Events with a photon, an electron or muon, a b-tagged jet, and missing transverse momentum are selected. A neural network based on kinematic variables differentiates between events from signal and background processes. The data are consistent with the background-only hypothesis, and limits are set on the strength of the tqγ coupling in an effective field theory. These are also interpreted as 95% CL upper limits on the cross section for FCNC tγ production via a left-handed (right-handed) tuγ coupling of 36 fb (78 fb) and on the branching ratio for t→γu of 2.8×10−5 (6.1×10−5). In addition, they are interpreted as 95% CL upper limits on the cross section for FCNC tγ production via a left-handed (right-handed) tcγ coupling of 40 fb (33 fb) and on the branching ratio for t→γc of 22×10−5 (18×10−5). © 2019 The Author(s

    Comparison between simulated and observed LHC beam backgrounds in the ATLAS experiment at Ebeam =4 TeV

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    Results of dedicated Monte Carlo simulations of beam-induced background (BIB) in the ATLAS experiment at the Large Hadron Collider (LHC) are presented and compared with data recorded in 2012. During normal physics operation this background arises mainly from scattering of the 4 TeV protons on residual gas in the beam pipe. Methods of reconstructing the BIB signals in the ATLAS detector, developed and implemented in the simulation chain based on the \textscFluka Monte Carlo simulation package, are described. The interaction rates are determined from the residual gas pressure distribution in the LHC ring in order to set an absolute scale on the predicted rates of BIB so that they can be compared quantitatively with data. Through these comparisons the origins of the BIB leading to different observables in the ATLAS detectors are analysed. The level of agreement between simulation results and BIB measurements by ATLAS in 2012 demonstrates that a good understanding of the origin of BIB has been reached
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