974 research outputs found

    The role of gravitational collapse in controlling the evolution of crestal fault systems (Espírito Santo Basin, SE Brazil)

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    A high-quality 3D seismic volume from offshore Espírito Santo Basin (SE Brazil) is used to assess the importance of gravitational collapse to the formation of crestal faults above salt structures. A crestal fault system is imaged in detail using seismic attributes such as curvature and variance, which are later complemented by analyses of throw vs. distance (T-D) and throw vs. depth (T-Z). In the study area, crestal faults comprise closely spaced arrays and are bounded by large listric faults, herein called border faults. Two episodes of growth are identified in two opposite-dipping fault families separated by a transverse accommodation zone. Statistical analyses for eighty-four (84) faults show that fault spacing is < 250 m, with border faults showing the larger throw values. Fault throw varies between 8 ms and 80 ms two-way time for crestal faults, and 60–80 ms two-way time for border faults. Fault length varies between ∼410 m and 1750 m, with border faults ranging from 1250 m to 1750 m. This work shows that border faults accommodated most of the strain associated with salt growth and collapse. The growth history of crestal faults favours an isolated fault propagation model with fault segment linkage being associated with the lateral propagation of discrete fault segments. Importantly, two episodes of fault growth are identified as synchronous to two phases of seafloor erosion, rendering local unconformities as competent markers of fault reactivation at a local scale. This paper has crucial implications for the understanding of fault growth as a means to assess drilling risk and oil and gas migration on continental margins. As a corollary, this work demonstrates that: 1) a certain degree of spatial organisation occurs in crestal fault systems; 2) transverse accommodation zones can form regions in which fault propagation is enhanced and regional dips of faults change in 4D

    A study on the negative binomial distribution motivated by Chv\'atal's theorem

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    Let B(n,p)B(n,p) denote a binomial random variable with parameters nn and pp. Chv\'{a}tal's theorem says that for any fixed n2n\geq 2, as mm ranges over {0,,n}\{0,\ldots,n\}, the probability qm:=P(B(n,m/n)m)q_m:=P(B(n,m/n)\leq m) is the smallest when mm is closest to 2n3\frac{2n}{3}. Motivated by this theorem, in this note we consider the infimum value of the probability P(XE[X])P(X\leq E[X]), where XX is a negative binomial random variable. As a consequence, we give an affirmative answer to the conjecture posed in [Statistics and Probability Letters, 200 (2023) 109871].Comment: 10 page

    3,3′-(2,2′-Bi-1H-imidazole-1,1′-diyl)dipropanol

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    In the title compound, C12H18N4O2, unlike other unconjugated disubstituted biimidazole derivatives reported so far, the two imidazole rings in a trans conformation exhibit a large planar rotation angle of 51.27 (4)°, and consist of half-mol­ecule asymmetric units related by a twofold rotation. The mol­ecules are linked into a three-dimensional framework with a parallel laminated construction via O—H⋯N and C—H⋯O inter­actions

    Intergreen Time Calculation Method of Signalized Intersections Based on Safety Reliability Theory: A Monte-Carlo Simulation Approach

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    In China, around ninety percent of the traffic accidents at signalized intersections occur within the signal change intervals, especially during signal change from green to red. Hence, intergreen time (IGT), that is, yellow change interval plus red clearance interval, is of great significance to the safety at signalized intersections. The conventional calculation method of IGT ignores the randomness of drivers’ behaviors, which we believe is an important factor in calculation of IGT. Therefore, the purpose of this research is to investigate a new approach to calculate the IGT based on safety reliability theory. Firstly, a comprehensive literature review concerning the conventional calculation methods of IGT is conducted. Secondly, a theoretical calculation method of IGT based on safety reliability theory is put forward; different from the conventional methods, this model accounts for the uncertainty of driving behavior parameters. Thirdly, a Monte-Carlo simulation is employed to simulate the interactive process of perception-reaction time (PRT) and vehicular deceleration and solve the proposed model. Finally, according to the Monte-Carlo simulation results, the curve clusters describing the relationship between IGT, safety reliability (50%-90%), and intersection width (15-35m) are drawn. Results show that the IGT of a signalized intersection, obeying the normal distribution, is influenced by multiple factors and most sensitive to the PRT and vehicular deceleration. Our method thus successfully incorporates the probabilistic nature of driving behavior. Taking the safety reliability into consideration can provide a more reasonable method to calculate the IGT of signalized intersections. Document type: Articl

    Revisiting van der Waals like behavior of f(R) AdS black holes via the two point correlation function

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    Van der Waals like behavior of f(R)f(R) AdS black holes is revisited via two point correlation function, which is dual to the geodesic length in the bulk. The equation of motion constrained by the boundary condition is solved numerically and both the effect of boundary region size and f(R)f(R) gravity are probed. Moreover, an analogous specific heat related to δL\delta L is introduced. It is shown that the TδLT-\delta L graphs of f(R)f(R) AdS black holes exhibit reverse van der Waals like behavior just as the TST-S graphs do. Free energy analysis is carried out to determine the first order phase transition temperature TT_* and the unstable branch in TδLT-\delta L curve is removed by a bar T=TT=T_*. It is shown that the first order phase transition temperature is the same at least to the order of 101010^{-10} for different choices of the parameter bb although the values of free energy vary with bb. Our result further supports the former finding that charged f(R)f(R) AdS black holes behave much like RN-AdS black holes. We also check the analogous equal area law numerically and find that the relative errors for both the cases θ0=0.1\theta_0=0.1 and θ0=0.2\theta_0=0.2 are small enough. The fitting functions between logTTc \log\mid T -T_c\mid and logδLδLc\log\mid\delta L-\delta L_c\mid for both cases are also obtained. It is shown that the slope is around 3, implying that the critical exponent is about 2/32/3. This result is in accordance with those in former literatures of specific heat related to the thermal entropy or entanglement entropy.Comment: Revised version. Match the published version. 14pages,5figure

    Transverse-Momentum Resummation for Gauge Boson Pair Production at the Hadron Collider

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    We perform the transverse-momentum resummation for W+WW^{+}W^{-}, ZZZZ, and W±ZW^{\pm}Z pair productions at the next-to-next-to-leading logarithmic accuracy using soft-collinear effective theory for S=8TeV\sqrt{S}=8 \text{TeV} and S=14TeV\sqrt{S}=14 \text{TeV} at the LHC, respectively. Especially, this is the first calculation of W±ZW^{\pm}Z transverse-momentum resummation. We also include the non-perturbative effects and discussions on the PDF uncertainties. Comparing with the next-to-leading logarithmic results, the next-to-next-to-leading logarithmic resummation can reduce the dependence of the transverse-momentum distribution on the factorization scales significantly. Finally, we find that our numerical results are consistent with data measured by CMS collaboration for the ZZZZ production, which have been only reported by the LHC experiments for the unfolded transverse-momentum distribution of the gauge boson pair production so far, within theoretical and experimental uncertainties.Comment: 22 pages, 6 figures, re-versio

    Transverse momentum resummation for color sextet and antitriplet scalar production at the LHC

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    We study the factorization and resummation of the transverse momentum spectrum of the color sextet and antitriplet scalars produced at the LHC based on soft-collinear effective theory. Compared to Z boson and Higgs production, a soft function is required to account for the soft gluon emission from the final-state colored scalar. The soft function is calculated at the next-to-leading order, and the resummation is performed at the approximate next-to-next-to-leading logarithmic accuracy. The non-perturbative effects and PDF uncertainties are also discussed.Comment: 20 pages, 7 figure

    Threshold resummation for the production of a color sextet (antitriplet) scalar at the LHC

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    We investigate threshold resummation effects in the production of a color sextet (antitriplet) scalar at next-to-next-to-leading logarithmic (NNLL) order at the LHC in the frame of soft-collinear effective theory. We show the total cross section and the rapidity distribution with NLO+NNLL accuracy, and we compare them with the NLO results. Besides, we use recent dijet data at the LHC to give the constraints on the couplings between the colored scalars and quarks.Comment: 21 pages,9 figures,3 tables; Version published in EPJ
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