173 research outputs found
Correction to: The effect of Aerobic-Resistance Training on the Expression of miR-222 and cTnT, Cx43, Ki67 Genes, and Cardiomyocyte Proliferation in Pre-Pubertal, Young, and Old Male Rats
No full textAzam Shahsavary1,
Bahman Mirzaei2,
Mohammad Reza Fadaei Chafy3,
Sarah Rajabi4
1 PhD Student of Exercise Physiology, Faculty of Physical Education and Sport Science, University of Guilan, Rasht, Iran
2 Professor of Exercise Physiology, Faculty of Physical Education and Sport Science, University of Guilan, Rasht, Iran
3 Assistant Professor, Department of Physical Education and Sport Science, Faculty of Humanities, Rasht Branch, Islamic Azad University, Rasht, Iran
4 Associate Professor, Department of Cell Engineering, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
Corresponding Author: Bahman Mirzaei - Faculty of Physical Education and Sport Science, University of Guilan, Rasht, Iran. (E-mail: [email protected])
In the article published in volume 33, issue 229, 2024, the original author order and corresponding author information were incorrect and have been corrected. The first author is Ms. Azam Shahsavary, and the second author is Dr. Bahman Mirzaei. Dr. Bahman Mirzaei is the corresponding author
Subsurface fracture analysis and determination of in-situ stress direction using FMI logs: An example from the Santonian carbonates (Ilam Formation) in the Abadan Plain, Iran
No full textThe relationship between the present-day stress field and natural fractures can have significant implications for subsurface fluid flow. In particular, fractures that are aligned in orientations favourable for reactivation by either shear or tensile failure in the in-situ stress field often exhibit higher hydraulic conductivities. The Ilam Formation of southwestern Iran is an important hydrocarbon reservoir containing numerous natural fractures. However, little is known about the state of stress in this region, or any of Iran's petroleum provinces. We conducted analysis of the present-day maximum horizontal stress orientation and the density, orientation and hydraulic conductivity of natural fractures in the Ilam carbonates using high resolution Formation Micro Imager resistivity logs in two wells. A total of 51 breakouts with an overall length of 215 m were observed in the two wells, indicating a maximum horizontal stress orientation of 68°N (± 7.6°) in well A and 58°N (± 6.3°) in well B. Furthermore, the wellbore-derived stress orientations determined herein are consistent with those inferred from nearby earthquake focal mechanism solutions, indicating that stresses in the sedimentary cover are linked to the resistance forces generated by Arabia–Eurasia collision. Furthermore, the correlation between stress orientations estimated from earthquake focal mechanism solutions and breakouts indicates that focal mechanism solution data, which is often considered to be unreliable for stress field analysis near transform margins, may provide reliable information on the stress orientation near continental collision zones. The image log data also reveals three sets of open, and presumably hydraulically conductive, fractures with strikes of (i) 160–170°N, (ii) 110–140°N and (iii) 070–080°N. Fracture set (iii) is consistent with being formed and open in the present-day stress field. However, fracture sets (i) and (ii) strike at a high angle to the present-day maximum horizontal stress, and are interpreted herein to be the result of either pre- or syn-folding related forces. The observation that different sets of open fractures in the field can be either sensitive or insensitive to the present-day stress is critical for improving hydrocarbon recovery.Mojtaba Rajabi, Shahram Sherkati, Bahman Bohloli and Mark Tinga
Mehanics of Rock Fragmentation Static and Dynamic Laboratory Testing Applied to Aggregate Production
No full textKnowing the strength properties of rocks is essential for calculating the stability of natural slopes, constructions in and on rock, excavations, blasting geometry, crushing, and drilling. When rock and rock masses are subjected to either dynamic or static loads, the tensile strength is determined by tests appropriate to the load type. Static tests include both indirect tests, such as the Brazilian test, and direct tests like the dumbbell-shaped direct pull. Conventional dynamic tests are the Hopkinson pressure bar and ultrasonic methods. This work has two objectives: (1) to characterize diverse rocks in terms of dynamic and static tensile failure behavior, and (2) to conduct problem-based research for minimizing the generation of fines by-product in rock fragmentation and comminution. Two major processes of aggregate production are blasting and crushing operations. The rock is subjected mainly to tensile stresses and failure in both processes. A method for measuring the quantity of rock fines was suggested for the Brazilian test. A working hypothesis for reducing the amount of rock fines in the Brazilian test was examined. Moreover, an analytical solution for discs subjected to the Brazilian test was also presented; this facilitates an accurate analysis of the Brazilian test for anisotropic rocks. Also, a Hopkinson pressure bar was constructed and then modified to measure the dynamic uniaxial tensile strength of rock cores in which rock fails in pure tension. Results showed that, for a specific type of rock, generation of fines depends on the tensile strength of the rock. The higher the tensile strength, the higher is the percentage of fines produced. The working hypothesis that reduction of the strength of rock through water saturation should reduce fines generation was examined and shown to be true for the rocks tested. The dynamic uniaxial tensile strength of gneiss and granodiorite was approximately the same as the static strength from the Brazilian test. Moreover, analytical solution showed that significant errors can be avoided by using the solution for determining the indirect tensile strength of anisotropic rocks
Mehanics of Rock Fragmentation Static and Dynamic Laboratory Testing Applied to Aggregate Production
No full textKnowing the strength properties of rocks is essential for calculating the stability of natural slopes, constructions in and on rock, excavations, blasting geometry, crushing, and drilling. When rock and rock masses are subjected to either dynamic or static loads, the tensile strength is determined by tests appropriate to the load type. Static tests include both indirect tests, such as the Brazilian test, and direct tests like the dumbbell-shaped direct pull. Conventional dynamic tests are the Hopkinson pressure bar and ultrasonic methods. <p />This work has two objectives: (1) to characterize diverse rocks in terms of dynamic and static tensile failure behavior, and (2) to conduct problem-based research for minimizing the generation of fines by-product in rock fragmentation and comminution. Two major processes of aggregate production are blasting and crushing operations. The rock is subjected mainly to tensile stresses and failure in both processes. <p />A method for measuring the quantity of rock fines was suggested for the Brazilian test. A working hypothesis for reducing the amount of rock fines in the Brazilian test was examined. Moreover, an analytical solution for discs subjected to the Brazilian test was also presented; this facilitates an accurate analysis of the Brazilian test for anisotropic rocks. Also, a Hopkinson pressure bar was constructed and then modified to measure the dynamic uniaxial tensile strength of rock cores in which rock fails in pure tension. <p />Results showed that, for a specific type of rock, generation of fines depends on the tensile strength of the rock. The higher the tensile strength, the higher is the percentage of fines produced. The working hypothesis that reduction of the strength of rock through water saturation should reduce fines generation was examined and shown to be true for the rocks tested. The dynamic uniaxial tensile strength of gneiss and granodiorite was approximately the same as the static strength from the Brazilian test. Moreover, analytical solution showed that significant errors can be avoided by using the solution for determining the indirect tensile strength of anisotropic rocks
Investigating tensile strength and fragmentation of anisotropic rocks in 3D using the Brazilian test
No full textOn the Arithmetic-Geometric Mean Inequality and its Relationship to Linear Programming, Matrix Scaling, and Gordan's Theorem
No full textIt is a classical inequality that the minimum of the ratio of the (weighted) arithmetic mean to the geometric mean of a set of positive variables is equal to one, and is attained at the center of the positivity cone. While there are numerous proofs of this fundamental homogeneous inequality, in the presence of an arbitrary subspace, and/or the replacement of the arithmetic mean with an arbitrary linear form, the new minimization is a nontrivial problem. We prove a generalization of this inequality, also relating it to linear programming, to the diagonal matrix scaling problem, as well as to Gordan's theorem. Linear programming is equivalent to the search for a nontrivial zero of a linear or positive semidefinite quadratic form over the nonnegative points of a given subspace. The goal of this paper is to present these intricate, surprising, and significant relationships, called scaling dualities, and via an elementary proof. Also, to introduce two conceptually simple polynomialtime algorithms that are based on the scaling dualities, significant bounds, as well as Nesterov and Nemirovskii's machinery of self-concordance. The algorithms are simultaneously applicable to linear programming, to the computation of a separating hyperplane, to the diagonal matrix scaling problem, and to the minimization of the arithmetic-geometric mean ratio over the positive points of an arbitrary subspace. The scaling dualities, the bounds, and the algorithms are special cases of a much more general theory on convex programming, developed by the author. For instance, via the scaling dualities semidefinite programming is a problem dual to a generalization of the classical trace-determinant ratio minimization over the positive definite points of a given subspace of the Hilbert space of symmetric matrices.Technical report DCS-TR-36
Erratum: The role of visual preferences in architecture views
No full textThe article “The role of visual preferences in architecture views” by Ali Akbar Amini, Bahman Adibzadeh, published on 24 September 2020 in the Journal of Architecture and Urbanism, 44(2), 122–127, https://doi.org/10.3846/jau.2020.12582 contained a following errors on:
122 p. The source is incorrectly cited in the text. The correct citation is:
(de la Fuente Suárez, 2016)
126 p. The references incorrectly indicate author name, lastname and title of article. The correct citation is:
de la Fuente Suárez, L. A. (2016). Towards experiential representation in architecture. Journal of Architecture and Urbanism, 40(1), 47–58. https://doi.org/10.3846/20297955.2016.1163243
Corrected version of the article is available online.
The publisher apologises for this error
An Analytical Solution for Pressure-Induced Deformation of Anisotropic Multilayered Subsurface
No full textpublishedVersio
Generalization Of Taylor's Theorem And Newton's Method Via A New Family Of Determinantal Interpolation Formulas
No full textThe general form of Taylor's theorem gives the formula, f = Pn + Rn, where Pn is the Newton's interpolating polynomial, computed with respect to a confluent vector of nodes, and Rn is the remainder. When f' /= 0, for each m = 2; : : : ; n + 1, we describe a "determinantal interpolation formula", f = Pm,n + Rm,n, where Pm,n is a rational function in x and f itself. These formulas play a dual role in the approximation of f or its inverse. For m = 2, the formula is Taylor's and for m = 3 it gives Halley's iteration function, as well as a Padé approximant. By applying the formulas to Pn, for each m >= 2, Pm,m-1,. . . , Pm,m+n-2, is a set of n rational approximations that includes Pn, and may provide a better approximation to f , than Pn. Thus each Taylor polynomial unfolds into an infinite spectrum of rational approximations. The formulas also give an infinite spectrum of rational inverse approximations, as well as a family of iteration functions for real or complex root finding, more fundamental than the Euler-Schröder family, or any other family. Given m >= 2, for each k <= m, we obtain a k-point iteration function, defined as the ratio of two determinants that depend on the first m - k derivatives, and Toeplitz for k = 1. The order of convergence ranges from m to the limiting ratio of the generalized Fibonacci numbers of order m. By applying these formulas, Hadamard's inequality, Gerschgorin's theorem, and a new lower bound on determinants, we express roots of numbers, e, and π, as the limiting ratio of Toeplitz determinants.Technical report DCS-TR-32
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