[en] I present estimates of CP-violating asymmetries in the non-leptonic charmonium two-body B⁰ → ψ(2S)π⁰ decay and the same decays of B⁺ → ψ(2S)π⁺, B⁰ → ψ(2S)K⁰ and B⁺ → ψ(2S)K⁺. These estimates are based on QCD and improved QCD factorization approach making use of next to-leading order (NLO) contributions. The CP-violating asymmetry for B⁰ → ψ(2S)π⁰ decay is not available. According to the same calculations, it is expected if it can be measured in the future its value will be S_ψ(2S)π⁰(B⁰→ψ(2S)π⁰) = 0.662 ± 0.197 and C_ψ(2S)π⁰(B⁰→ψ(2S)π⁰) = 0.024±0.007.

[en] In this research, the plane stress fracture toughness of ultra-fine grained aluminum specimens produced through accumulative roll bonding (ARB) process was investigated for the first time. The specimens were produced successfully by the ARB process up to 7 cycles with the amount of 50% thickness reduction in each cycle at room temperature without using lubricant. The fracture toughness was evaluated for the annealed and different ARB cycles using ASTM E561 standard and compact tension specimens. Additionally, mechanical properties, tensile fracture surfaces and crystallite size of ultra-fine grained aluminum ARBed specimens were evaluated by uniaxial tensile tests, microhardness measurements, scanning electron microscopy and X-ray diffraction. By increasing the number of the ARB cycles, fracture toughness was increased and the maximum value of this parameter was achieved in the last cycle, which was approximately 25.4 MPam^1/2 that it increased by 155% higher than the annealed specimen. Results of X-ray diffraction demonstrated that by increasing the number of the ARB cycles, crystallite size decreased so that it reached 175 nm for the 7th cycle ARBed specimen from 1341 nm for annealed samples. Furthermore, by increasing the number of the ARB cycles up to the 7th cycle, tensile strength and microhardness of ultra-fine grained aluminum increased to 232 MPa and 51VHN, respectively. At first, the value of elongation decreased and then increased. The SEM results showed that ductile fracture mode with large dimples occurring in the annealed specimen, changed to shear ductile fracture with elongated sophomoric shear and fine dimples after the ARB process.

[en] In this paper, we have investigated the two-body decay of 𝐵⁰_𝑠 meson into 𝐷^∗−_𝑠 and 𝐾^∗+ which is not observed yet. However, some similar decays, such as 𝐵⁰_𝑠→𝐷^∗−_𝑠𝜌⁺ and 𝐵⁰𝑠→𝐷^¯∗0𝜙, have been observed with numerical experimental branching ratios. To ensure our obtained results for 𝐵0𝑠→𝐷^∗-_𝑠𝐾^∗+ decay, we have applied the used method on similar observed decays. The 𝐵⁰_𝑠→𝐷^∗-_𝑠𝐾^∗+ decay has been calculated using different methods in other literature works, and their results are comparable with the results of the current work. The most precise determinations for the branching fractions of 𝐵⁰_𝑠→𝐷^∗-_𝑠𝐾⁺ and 𝐵⁰_𝑠→𝐷^∗-_𝑠𝜋⁺ decays have been reported by the LHCb and Belle collaborations with the values of B(𝐵⁰_𝑠→𝐷^∗-_𝑠𝐾⁺) = (1.63±0.12)×10^-4 and B(𝐵⁰_𝑠→𝐷^∗−_𝑠𝜋⁺)=(2.40±0.30)×10^-3, respectively. Therefore, we have also calculated the branch ratios of these decay modes and obtained the numerical results as B(𝐵⁰_𝑠→𝐷^∗-_𝑠𝐾⁺)=(1.68±0.17)×10^-4 and B(𝐵⁰_𝑠→𝐷^∗-_𝑠𝜋⁺)=(2.22±0.17)×10^-3, that are much more consistent with the experimental results. The ratio of these, 0.076±0.014, is also in good agreement with the ratio reported by LHCb collaboration, 0.068±0.005. (author)

[en] We investigate the B⁰→|D over bar|*(2007)^0π+π- decay using Dalitz plot analysis. There are two tree diagrams for this decay mode in the factorization approach: the transition matrix element is factorized into a B⁰ → π⁺π^- form factor multiplied by |D over bar|*(2007)⁰ decay constant; and a B⁰ → |D over bar|*(2007)⁰π^- form factor multiplied by a π⁺ decay constant. In this research we evaluate the matrix elements of the vector and axial vector currents between the B⁰ and |D over bar|*(2007)⁰π^- meson states by using the B*⁺ pole. The contributions of intermediate resonances, such as f₀(980), f₀(1370), f₀(1500) and ρ(770), ρ(1450), ρ(1700), have been taken into account. According to the QCD factorization approach and using Dalitz plot analysis, we calculate the branching ratio of B⁰ → |D over bar|^*(2007)⁰π⁺π^- decay and obtain 3.81 ± 1.31 x 10^-4 and 7.49 ± 2.71 x 10^-4 at the μ = m_b and 2m_b scales, respectively, whereas the experimental result is (6.20 ± 2.20) x 10^-4. (author)

[en] This book is aimed at applied mathematicians interested in numerical simulation of turbulent flows. The book is centered around the k - ε model but it also deals with other models such as subgrid scale models, one equation models and Reynolds Stress models. The reader is expected to have some knowledge of numerical methods for fluids and, if possible, some understanding of fluid mechanics, the partial differential equations used and their variational formulations. This book presents the k - ε method for turbulence in a language familiar to applied mathematicians, stripped bare of all the technicalities of turbulence theory. The model is justified from a mathematical standpoint rather than from a physical one. The numerical algorithms are investigated and some theoretical and numerical results presented. This book should prove an invaluable tool for those studying a subject that is still controversial but very useful for industrial applications. (authors). 71 figs., 200 refs

[en] We investigate the effects of final-state-interactions (FSI) contributions in the nonleptonic two-body B⁺ → D_s⁺K⁰-bar decay; however, the hadronic decay of B⁺ → D_s⁺K⁰-bar is analyzed by using 'QCD factorization' (QCDF) method and final-state interaction (FSI). First, the B⁺→D_s⁺K⁰-bar decay is calculated via QCDF method and only the annihilation graphs exist in that method. Hence, the FSI must be seriously considered to solve the B⁺→D_s⁺K⁰-bar decay and the D⁰π⁺(D^0∗ρ⁺), D⁺π⁰(D^+∗ρ⁰) and D⁺η_c(D^+∗ J/ψ) via the exchange of K^+(∗), K^0(∗) and D_s^+(∗) mesons are chosen for the intermediate states. To estimate the intermediate states amplitudes, the QCDF method is again used. These amplitudes are used in the absorptive part of the diagrams. The experimental branching ratio of B⁺→D_s⁺K⁰-bar decay is less than 8·10^-4 and the predicted branching ratio is 0.23·10^-9 in the absence of FSI effects and it becomes 6.74·10^-4 when FSI contributions are taken into account.

[en] In this research, the hadronic decay of B⁰ → J/ψρ⁰ is analyzed by using the QCD factorization (QCDF) and final state interaction (FSI). The D^+(∗)D^-(∗) for d d-bar and D^0(∗) D-bar ^0(∗) for u ū contributions via the exchange of charmed mesons are chosen for the intermediate states. These amplitudes are calculated by using QCDF and used in the absorptive part of the diagrams. The experimental branching ratio of B⁰ → J/ψρ⁰ decay is (2.7 ± 0.4)·10^-5 and our results according to the QCDF method and FSI are 0.87·10^-5 and (0.057-4.18)·10^-5, respectively

[en] In current effluent discharge standards of the most countries such as Iran, self-purification capacity of rivers have not been considered. These standards developed a similar effluent discharge standard for all of the rivers without considering hydrological and hydraulic conditions of rivers. In this paper in order to show the importance of self-purification capacity and differences between the rivers, in developing effluent discharge standard, two rivers- Gheshlagh River in Kurdistan and Sabzkooh River in Chaharmahal Bakhtiari- as samples were selected., and with applying Qual2kw model, current Iran effluent discharge standards were used to simulate the state of each river. The simulation showed that compliance with this standard maintain an appropriate qualitative condition of Gheshlagh River but in Sabzkoh River, due to the large number of pollution sources, these standards not only does not help to maintain the water quality but will have a very negative impact on water quality. Then Using simulation of river quality, the authorized appropriate limit based on self-purification capacity and the number and type of pollutants were estimated and showed that to develop accurate and efficient standards the self-purification capacity, the number of pollution sources, the amount of waste load and other different conditions of rivers also should be considered.

[en] Spectrophotometric and potentiometric techniques were used to determine the formation constants of the species formed in the systems H⁺ + W(VI) + ethylenediaminediacetic acid and H⁺ + ethylenediaminediacetic acid in aqueous solutions of propanol at 25 deg C and constant ionic strength 0.1 mol dm^-3 of sodium perchlorate. The composition of the complex was determined by the continuous variations method. It was shown that tungsten (VI) forms a mononuclear 1 : 1 complex with ethylenediaminediacetic acid of the type WO₃L^3- at -log[H⁺] = 5.8. The formation constants in various media were analyzed in terms of Kamlet and Taft's parameters. Solvents have been parameterized by scales of dipolarity/polarizability π*, hydrogen-bond donor strength α, and hydrogen-bond acceptor strength β. Linear dependence on these solvent parameters are used to correlate and predict a wide variety of solvent effects, as well as to provide an analysis of them. Linear relationships are observed when logK_S is plotted versus π*. Finally, the results are discussed in terms of the effect of solvent on complexation

[en] In this study, for the first time, the effect of applied strains and volume percentage of components of layered composite on the mechanical properties and fracture toughness of Al/Mg were investigated experimentally. The multilayered Al/Mg were produced by the accumulative roll bonding (ARB) process. For the investigation, three Al/Mg composites with different volume percentages (25%, 50%, and 66.6%Al) at different applied strains (0.8–3.2) were produced. The experimental evaluation included microscopic examination by optical microscope imaging, uniaxial tensile test, and plane strain fracture toughness. As the applied strain for all three composites increased, plastic instability in the magnesium reinforcement intensified, but due to the low thickness of the Al layers compared to the Mg layer, uniform structure of Mg distribution in Al for all three composite was not achieved. Also, by adding Al layers to the primary composite, a lower shear strain was applied to the magnesium reinforcement, and instability intensity in the reinforcement layer decreased. For this reason, as Al layers increased, plastic instability diminished. By raising the exerted strain, the values of tensile strength increased, and by adding Al layers, the elongation increased. The maximum amount of tensile strength and elongation for each composite was achieved in the same ARB pass (last pass) and the highest values of UTS and elongation were reached to 384.1 MPa and 1.95% for Al25%Mg, respectively. However, the highest amount of fracture toughness for each composite was obtained in the different exerted strains and the maximum value of 41.4 MPa·m^1/2 was achieved for Al33.3% in the third pass. The present phenomena indicated that many factors such as higher Mg volume with higher energy absorption, plastic instability, thickness ratio, plastic instability, and value of applied strain affected the fracture toughness. In summary, the relationship between fracture toughness with applied strain and also with volume percent of Al was not always straightforward. It depends on other factors, such as how the reinforcement was distributed, the thickness of the layers, the workability, and the addition of aluminum. Also, the applied strain has a more significant effect on increasing fracture toughness in multilayered composite if they cause a uniform distribution of reinforcement particles in the field or continuity in the reinforcement layer. (paper)