Optimized Design of Statically Equivalent Mooring and Catenary Ryser Systems

Due to size limitations of wave basins worldwide it is necessary to employ statically equivalent truncated mooring and riser systems to test floating systems to be deployed in deep and ultra-deep waters. A procedure for the optimized design of the statically equivalent truncated mooring and riser system was developed using a Genetic Algorithm, considering that the equivalent mooring/system needs to reproduce the net static forces and moments exerted by the prototype mooring/riser system on the floater in its six rigid body degrees of freedom (surge, sway, heave, roll, pitch and yaw). A fit-for-purpose program was developed to evaluate the three-dimensional static equilibrium of floating structures, considering the attached mooring and steel catenary riser systems. The static response is calculated for a set of offsets in the surge direction from the calm water equilibrium position up to a maximum user defined offset. Four study cases were considered to demonstrate the effectiveness and robustness of a Genetic Algorithm procedure developed for the optimize design of the statically equivalent mooring and riser system. The four study cases were a semisubmersible with a symmetric polyester mooring system, a semisubmersible with a symmetric steel wire mooring system, a semisubmersible with a non-symmetric polyester mooring and steel catenary riser system attached, and a spar with a non-symmetric polyester mooring and a steel catenary riser system attached. To gain insight on the distortion of the dynamic mooring forces exerted on the floater when dynamic effects are ignored in the design, a procedure to assess the mooring system inertia and damping force contributions to the floater was developed. The application of the procedure was demonstrated using two study cases corresponding to deepwater polyester and steel mooring systems

Heterogeneous and rate-dependent streptavidin-biotin unbinding revealed by high-speed force spectroscopy and atomistic simulations

Receptor-ligand interactions are essential for biological function and their binding strength is commonly explained in terms of static lock-and-key models based on molecular complementarity. However, detailed information of the full unbinding pathway is often lacking due, in part, to the static nature of atomic structures and ensemble averaging inherent to bulk biophysics approaches. Here we combine molecular dynamics and high-speed force spectroscopy on the streptavidin-biotin complex to determine the binding strength and unbinding pathways over the widest dynamic range. Experiment and simulation show excellent agreement at overlapping velocities and provided evidence of the unbinding mechanisms. During unbinding, biotin crosses multiple energy barriers and visits various intermediate states far from the binding pocket while streptavidin undergoes transient induced fits, all varying with loading rate. This multistate process slows down the transition to the unbound state and favors rebinding, thus explaining the long lifetime of the complex. We provide an atomistic, dynamic picture of the unbinding process, replacing a simple two-state picture with one that involves many routes to the lock and rate-dependent induced-fit motions for intermediates, which might be relevant for other receptor-ligand bonds.Comment: 21 pages, 4 figure

Generalized μ−τ\mu-\tau reflection symmetry and leptonic CP violation

We propose a generalized $\mu-\tau$ reflection symmetry to constrain the lepton flavor mixing parameters. We obtain a new correlation between the atmospheric mixing angle $\theta_{23}$ and the "Dirac" CP violation phase $\delta_{\rm CP}$. Only in a specific limit our proposed CP transformation reduces to standard $\mu-\tau$ reflection, for which $\theta_{23}$ and $\delta_{CP}$ are both maximal. The "Majorana" phases are predicted to lie at their CP-conserving values with important implications for the neutrinoless double beta decay rates. We also study the phenomenological implications of our scheme for present and future neutrino oscillation experiments including T2K, NO$\nu$A and DUNE.Comment: 14 pages, 9 figures, latex, Final version to appear in Physics Letters

On dd-stable locally checkable problems parameterized by mim-width

In this paper we continue the study of locally checkable problems under the framework introduced by Bonomo-Braberman and Gonzalez in 2020, by focusing on graphs of bounded mim-width. We study which restrictions on a locally checkable problem are necessary in order to be able to solve it efficiently on graphs of bounded mim-width. To this end, we introduce the concept of $d$-stability of a check function. The related locally checkable problems contain large classes of problems, among which we can mention, for example, LCVP problems. We give an algorithm showing that these problems are XP when parameterized by the mim-width of a given binary decomposition tree of the input graph, that is, that they can be solved in polynomial time given a binary decomposition tree of bounded mim-width. We explore the relation between $d$-stable locally checkable problems and the recently introduced DN logic (Bergougnoux, Dreier and Jaffke, 2022), and show that both frameworks model the same family of problems. We include a list of concrete examples of $d$-stable locally checkable problems whose complexity on graphs of bounded mim-width was open so far

Gender Differences in Law Enforcement Leadership Style: Implications for Subordinate Job Satisfaction

Undergraduate Applie

Communication: Unambiguous comparison of many-electron wavefunctions through their overlaps

© 2016 Author(s). A simple and powerful method for comparing many-electron wavefunctions constructed at different levels of theory is presented. By using wavefunction overlaps, it is possible to analyze the effects of varying wavefunction models, molecular orbitals, and one-electron basis sets. The computation of wavefunction overlaps eliminates the inherent ambiguity connected to more rudimentary wavefunction analysis protocols, such as visualization of orbitals or comparing selected physical observables. Instead, wavefunction overlaps allow processing the many-electron wavefunctions in their full inherent complexity. The presented method is particularly effective for excited state calculations as it allows for automatic monitoring of changes in the ordering of the excited states. A numerical demonstration based on multireference computations of two test systems, the selenoacrolein molecule and an iridium complex, is presented