17 research outputs found

    A new approach to calculate the gluon polarization

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    We derive the Leading-Order master equation to extract the polarized gluon distribution G(x;Q^2) = x \deltag(x;Q^2) from polarized proton structure function, g1p(x;Q^2). By using a Laplace-transform technique, we solve the master equation and derive the polarized gluon distribution inside the proton. The test of accuracy which are based on our calculations with two different methods confirms that we achieve to the correct solution for the polarized gluon distribution. We show that accurate experimental knowledge of g1p(x;Q^2) in a region of Bjorken x and Q^2, is all that is needed to determine the polarized gluon distribution in that region. Therefore, to determine the gluon polarization \deltag /g,we only need to have accurate experimental data on un-polarized and polarized structure functions (F2p (x;Q^2) and g1p(x;Q^2)).Comment: 12 pages, 5 figure

    Thermodynamics of Charged Brans-Dicke AdS Black Holes

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    It is well-known that in four dimensions, black hole solution of the Brans-Dikce-Maxwell equations is just the Reissner-Nordstrom solution with a constant scalar field. However, in n4n\geq4 dimensions, the solution is not yet the (n+1)(n+1)-dimensional Reissner-Nordstrom solution and the scalar field is not a constant in general. In this paper, by applying a conformal transformation to the dilaton gravity theory, we derive a class of black hole solutions in (n+1)(n+1)-dimensional (n4)(n\geq 4) Brans-Dikce-Maxwell theory in the background of anti-de Sitter universe. We obtain the conserved and thermodynamic quantities through the use of the Euclidean action method. We find a Smarr-type formula and perform a stability analysis in the canonical ensemble. We find that the solution is thermally stable for small α\alpha, while for large α\alpha the system has an unstable phase, where α\alpha is a coupling constant between the scalar and matter field.Comment: 14 pages, one figure, to appear in Phys. Lett.

    The global burden of cancer attributable to risk factors, 2010–19: a systematic analysis for the Global Burden of Disease Study 2019

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    BACKGROUND: Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. METHODS: The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk–outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. FINDINGS: Globally, in 2019, the risk factors included in this analysis accounted for 4·45 million (95% uncertainty interval 4·01–4·94) deaths and 105 million (95·0–116) DALYs for both sexes combined, representing 44·4% (41·3–48·4) of all cancer deaths and 42·0% (39·1–45·6) of all DALYs. There were 2·88 million (2·60–3·18) risk-attributable cancer deaths in males (50·6% [47·8–54·1] of all male cancer deaths) and 1·58 million (1·36–1·84) risk-attributable cancer deaths in females (36·3% [32·5–41·3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20·4% (12·6–28·4) and DALYs by 16·8% (8·8–25·0), with the greatest percentage increase in metabolic risks (34·7% [27·9–42·8] and 33·3% [25·8–42·0]). INTERPRETATION: The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden

    Polarized parton distribution in the relativistic quark exchange framework

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    The Spin dependent gluon and sea quark distributions of the proton and the neutron are extracted in the leading order (LO) and the next-to-leading order (NLO) QCD. The relativistic quark exchange model is used to calculate the related valence quark spin dependent structure function. The inverse Mellin transform technique is performed to evaluate the polarized x-dependent distributions of the gluon and the sea quark from the various moments of the valence quarks. It is shown that the calculated spin structure functions (SSF) of the proton and the neutron are in good agreement with the available data, such as E143, SMC, E142, E154 and Hermes experiments. A comparison is also made with the other theoretical models. Finally it is shown that the above calculated parton distributions improve the SSF of the proton and the neutron

    The Q2Q^2 dependence of polarized and unpolarized proton structure functions in the relativistic quark exchange framework

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    In this article we intend to discuss the evolution of polarized and unpolarized structure functions in the (x,Q2)(x,Q^2) plane. We analyze the proton data on the spin dependence asymmetry A1(x,Q2)A_1(x,Q^2), by making the dynamical assumption that at low resolution energies, the hadrons consist only of valence quarks and the scaling violation of F2(x,Q2)F_2(x,Q^2) at low xx comes only from the gluons density. While the sea quark and the gluon distributions are calculated using the inverse Mellin technique and the various moments of the valence quarks, the valence quark distribution itself is obtained from the relativistic quark-exchange model. A comparison is made with the corresponding available experimental data. Finally in agreement with the data, it is demonstrated that there is no significant Q2Q^2-dependence of asymmetry A1(x,Q2)A_1(x, Q^2) for x ranging 0.014x0.250.014\le x \le 0.25

    Experimental Investigations on a Novel Chemical Looping Combustion Configuration

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    Chemical Looping Combustion (CLC) is a promising novel combustion technology involving inherent separation of carbon dioxide with minimum energy penalty. An oxygen carrier is employed to continuously transfer oxygen from the air reactor to the fuel reactor where the oxygen is delivered to the fuel. Consequently, direct contact between the air and fuel is prevented. The resulting flue gas is CO2-rich, without N2 dilution. The reduced oxygen carrier is then transported back to the air reactor for re-oxidation purposes, hence forming a chemical loop. Various CLC configurations have already been developed and tested on laboratory scales. However, more investigations are required to achieve feasible CLC processes. Among the different points to address, control of the solid circulation rate between the two reactors is of the highest importance regarding its effect on achievement of an appropriate oxygen transfer rate and solid oxidation degrees. Moreover, minimization of gas leakage between the fuel and air reactors is another important issue to be considered. A novel CLC configuration is proposed where reactions are carried out in two interconnected bubbling fluidized beds. Solid circulation rate control is achieved independently of gas flow rate in the reactors through use of pneumatic non-mechanical valves (L-valves). Moreover, loopseals are employed to minimize gas leakage while transferring solids. Experimental results from operation of a 10 kWth equivalent cold prototype are presented in this paper. The effect of operating variables on the solid circulation rate, gas leakage between the two beds and the pressure balance on all of the process elements is studied. The results demonstrate stable solid circulation with efficient control of the solid flow rate and effective gas tightness of the system

    The relationship between different diet quality indices and severity of airflow obstruction among COPD patients

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    Background: Chronic obstructive pulmonary disease (COPD) is a major public health problem worldwide. Smoking is the number one cause of COPD; however, genetic, environmental and dietary factors contribute to the etiology of this disease. In this study, we assessed the association between three diet quality indices -the Healthy Eating Index-2005 (HEI-2005), the Healthy Eating Index-2010 (HEI-2010), and Mediterranean Diet Score (MED)- and the severity of disease in COPD patients. Methods: This cross-sectional study was performed at Rasul-e-Akram Hospital in Tehran on 121 COPD patients with the mean age of (SD) of 66.1(10.9) years. A pulmonary specialist diagnosed all participants based on a spirometry test. They were categorized into four groups (1, 2, 3, 4 stages of disease). Three diet quality indices, spirometry test and determination of disease severity were performed for all the participants. ANCOVA and Kruskal-Wallis test were used to assess the relationship between dietary quality indices and severity of the disease. The relationship between HEI-2010, HEI-2005, MED score, their components and lung function was assessed using a multiple linear regression analysis. All analyses were done using SPSS 18. Results: Reduction of the Healthy Eating Index-2010 and MED score were observed along with the increase in disease severity, but they were not significant. The relationship between the three diet quality indices and lung function showed a significant association between MED score and Forced expiratory volume in one second (FEV1), The Forced Vital Capacity (FVC) (β=2.9, 95 CI (1.1, 4.8), p=0.002), (β=2.8, 95 CI (0.9, 4.8), p=0.007), respectively. Conclusion: Mediterranean dietary pattern and obtaining a better score on HEI-2010 diet were associated with a better lung function test
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