Final Moment Research Articles

Partially encased composite steel and concrete columns: a systematic approach to the literature

Partially encased composite columns emerge as a promising solution in structural engineering, combining the versatility of steel with the durability of concrete. This article explores their characteristics and advantages, highlighting the construction efficiency and resource savings they offer compared to traditional reinforced concrete structures. While steel provides strength and speed in construction, concrete offers protection against fire and compression. The study consisted of two stages: the systematic literature review, in which the most relevant bibliography for the objective of the article was selected, and the meta-analysis stage. The studies indicated a decrease in the initial stiffness, maximum load and ultimate strength of the columns, with an increase in eccentricity, as well as an increase in the peak axial load and final moment of resistance in high-strength concrete, especially in slender columns which present reduced peak axial load due to the increase in the slenderness index. Furthermore, partially encased columns demonstrated superior compressive strength to steel at high temperatures. Therefore, these columns represent a promising option, subject to additional considerations and specific studies.

Fast and robust production of quantum superposition states by the fractional shortcut to adiabaticity

The fractional shortcut to adiabaticity (f-STA) for the production of quantum superposition states is proposed firstly via a three-level system with a Λ-type linkage pattern and a four-level system with a tripod structure. The fast and robust production of the coherent superposition states is studied by comparing the populations for the f-STA and the fractional stimulated Raman adiabatic passage (f-STIRAP). The states with equal proportions can be produced by fixing the controllable parameters of the driving pulses at the final moment of the whole process. The effects of the pulse intensity and the time delay of the pulses on the production process are discussed by monitoring the populations on all of the quantum states. In particular, the spontaneous emission arising from the intermediate state is investigated by the quantum master equation. The result reveals that the f-STA exhibits superior advantages over the f-STIRAP in producing the superposition states.

The End of the Ottoman Empire: A Century after the Fall

A century ago, the Ottoman Empire finally ceased to be after a long reign that stretched back to the late medieval period, and, ostensibly, nobody really missed it. It was once possible to write about the fall of the Ottoman Empire as the overdue culmination of a process that gave rise to independent nation–states. But, increasingly, the empire casts a long shadow on the historiography of the Middle East, and its last days emerge among its most consequential for the future of the region. The same political actors who reshaped late Ottoman politics were integral to the struggle for the post-Ottoman landscape. These individuals included provincial elites from nondominant ethnic groups who, rather than embracing ethnic nationalism, remained Ottomanist in their vision of the region's future until the final moment. Newer scholarship rejects the teleology of the nations that emerged from postwar fracturing, demonstrating that the map was not redrawn by the victors in an instant. It was forged, instead, through armed struggles against European imperial powers and among rival movements that lasted for years. One hundred years after the Ottoman Empire's collapse, historians are still excavating its long-ignored relevance for understanding the modern Middle East, which was buried under the weight of nationalist and Orientalist metanarratives that never questioned the inevitability of its demise.

Regional Security, Problems and Influencing Factors: A Case Study of Albania

The new national, regional and global security environment and its trends are expressed in a synthesized way in the National Security Strategy. Our region is increasingly characterized, on the one hand, by overcoming the old mindsets of confrontation between states and the perceptible reduction of traditional threats, by the promotion of a new spirit of cooperation and the values of integration in the collective security structures and on the other hand, it is facing a new nature of challenges, dangers and threats with non-traditional, asymmetric forms and contents, on terrorist, ethnic or other grounds, initiated by nationalist-extremist elements and groups. Receiving the long-awaited invitation to the Bucharest Summit in April 2008, as well as the final moment for NATO accession at the NATO Summit in Stratsburg and Kehl, marks a qualitative stage in the complete process of Albania in the Euro-Atlantic structures. In this new perspective, the security and defense of our country will suffer qualitative effects; from the concept of individual security and protection, it will finally be passed "de jure" to the concept of collective security and protection, accompanied by all the relevant benefits and contributions. Likewise, the new states of Kosovo and Montenegro have given our region a new favorable panorama of regional security. Going forward, our assessments of the security environment, expected risks and threats, and the spectrum of FARSH combat and non-combat missions will be significantly influenced by the collective security assessments articulated in the Alliance's Strategic Concept (CSC), Policy of European Security and Defense (ESDP) and the Charter of the United Nations. In this new perspective, in full accordance with the constitutional obligations, FARSH to adopt a new defense planning system, in harmony with the standards and planning processes of the Euro-Atlantic Alliance. Keywords: Influencing factors, Regional security, NATO, National security

Influence of Internal and External Foot Rotation on Peak Knee Adduction Moments and Ankle Moments during Gait in Individuals with Knee Osteoarthritis: A Cross-Sectional Study.

The aim of the study was to verify the effects of foot progression angle (FPA) modification during walking on the internal moments of the ankle and knee joints in individuals with knee osteoarthritis (OA). Biomechanical changes such as increased knee adduction moment (KAM) during walking are known to be involved in the development and severity of knee OA. Although various FPA modifications during gait have been applied to reduce peak KAM, few studies have investigated the effects of applying toe-in or toe-out walking modifications for knee OA on peak KAM and three-dimensional (3D) moments of the ankle joint. Kinetic moment variables were acquired from 35 individuals with medial knee compartment OA. A 3D motion analysis system and two force platforms were used to acquire KAM and 3D moments of both ankle joints during gait. Visual3D was used to obtain final moment data for statistical processing. Repeated-measures analysis of variance with Bonferroni adjustment was used to compare kinetic and kinematic values for each FPA walking condition. There was a significant decrease (p < 0.01) in first peak KAM when walking with an internal rotation foot position compared to normal foot position walking. Also, there was a significant decrease (p < 0.01) in second peak KAM when walking with an external rotation foot position compared to normal foot position walking. Compared to a normal foot position, peak ankle inversion moment of the external rotation foot position walking showed a significant decrease (p < 0.05). There were no interactive effects between FPA condition and limb sides for any KAM values (p > 0.05). The results showed no significant increase in the ankle joint moment value during gait for FPA modification conditions. Thus, the clinical implications of this study suggest that modification of the FPA in patients with OA to reduce KAM does not negatively impact the 3D ankle moments.

Stability estimates for some parabolic inverse problems with the final overdetermination via a new Carleman estimate

This paper is about Hölder and Lipschitz stability estimates and uniqueness theorems for some coefficient inverse problems and associated inverse source problems for a general linear parabolic equation of the second order with variable coefficients. The data for the inverse problem are given at the final moment of time . In addition, both Dirichlet and Neumann boundary conditions are given either on a part or on the entire lateral boundary. Thus, if these boundary conditions are given only at a part of the boundary, then even if the target coefficient is known, still the forward problem is not a classical initial boundary value problem.

Fault Coalescence, Slip Distribution, and Stress Drop of the February 2023 Southeast Türkiye Earthquakes from Joint Inversion of SAR, GNSS, and Burst Overlap Interferometry

Abstract Two devastating earthquakes struck southeastern Türkiye and northwestern Syria on 6 February 2023: an Mw 7.8 mainshock, followed 9 hr later by an Mw 7.6 aftershock. To recover and separate the subsurface geometry and slip distributions along the two earthquake faults, we jointly invert Interferometric Synthetic Aperture Radar, Synthetic Aperture Radar pixel offset tracking, burst overlap interferometry (BOI), Global Navigation Satellite System, and aftershock datasets. We introduce a new Kalman filter-based approach for merging spatially dense azimuth offset (AZO) data with the more precise yet spatially sparse BOI data. This procedure yields improved measurements of the displacements parallel to the near north-south satellite tracks, which are critical for resolving slip along most of the Mw 7.8 fault segments. We optimize the inversion using a new metric for assessing the degree of spatial correlation between the coseismic slip gradients and early aftershocks, resulting in a stable solution honoring the complementarity between the geodetic and aftershock datasets. The analysis suggests that the Mw 7.8 rupture consisted of three large segments and two short fault branches, covering about 300 km along the East Anatolian fault (EAF), whereas the Mw 7.6 rupture consisted of three segments extending for about 160 km along the nearby Sürgü fault (SF). On the basis of moment-to-stress-drop scaling relations, we show that the Mw 7.6 stress drop is four times larger than the Mw 7.8 stress drop, consistent with the larger recurrence intervals for Mw &amp;gt; 7 earthquakes on the SF than on the EAF. The moment released during the 2023 Mw 7.8 earthquake is 2–4 times larger than the sum of the moments released during individual historical Mw &amp;gt; 7 earthquakes along the three segments of the 2023 Mw 7.8 earthquake. Thus, when considering moment release for multisegment earthquakes, one should note that the final moment of fault coalescence is likely larger than the arithmetic sum of individual segment ruptures.

The Angel in the Juniper

Are the pious loved by the gods because they are pious, or are they pious because they are loved by the gods?” In this work of philosophical short story fiction, Professor Adamson and the narrator discuss Euthyphro’s dilemma. The narrator is invited by her professor to follow her into the woods and to meet a reclusive revolutionary leader. The professor, and the revolutionary group, want to overthrow the government because voting rights, and other civil rights, have been severely restricted by the government. The legal ability to change the government through voting is a “near impossibility.” On her way to meet the leader, the narrator meets an angel who informs her that the future revolution will fail, and many will be hurt in the process. The angel tells the narrator she must kill her professor to help humanity. The narrator is unsure what to do and, during their walk, discusses the dilemma she is in; a practical application of Euthyphro’s dilemma. The story ends in the final moment, knife in hand, when the narrator is about to decide what she will do.

Inverse parabolic problems by Carleman estimates with data taken at initial or final time moment of observation

Inverse parabolic problems by Carleman estimates with data taken at initial or final time moment of observation

Determination of a source term in Schrödinger equation with data taken at final moment of observation

Determination of a source term in Schrödinger equation with data taken at final moment of observation

Универсальный метод Монте-Карло для процессов Леви и его экстремумов

The article proposes a universal approach to constructing Monte Carlo methods for pricing options with payoffs depending on the joint distribution of the final position of the Lévy process X_T and its infimum J_T (or supremum S_T). We derive approximate formulas for the conditional cumulative distribution functions of the Lévy process "P"(X_T&lt;x|S_T=y) (P(X_T&lt;x|J_T=y)), which are expressed through the partial derivative with respect to y of the joint cumulative distribution function "P"(X_T&lt;x,S_T&lt;y) (P(X_T&lt;x,J_T&lt;y)) and the density of the infimum (or supremum) at the final moment of time. By applying the Laplace transform to the joint cumulative distribution function of the Lévy process and its extremum, we use the approximate Wiener–Hopf factorization to represent the image of its partial derivative. By inverting the Laplace transform using the Gaver–Stehfest algorithm, we find the desired conditional cumulative distribution function. The developed algorithm for simulating the joint position of the Lévy process and its extremum at a given point in time consists of two key stages. At the first stage, we simulate the extremum value of the L´evy process based on the approximation of its cumulative distribution function "P"(S_T&lt;x) (or P(J_T&lt;x)). In the second step, we simulate the final value of the Lévy process based on the approximation of the conditional cumulative distribution function of the final position of the Lévy process relative to its extremum. The universality of the Monte Carlo method we developed lies in the implementation of a uniform approach for a wide class of Lévy processes, in contrast to classical approaches, when simulations are essentially based on the features of the probability distribution associated with the simulated random process or its extrema. In our approach, it is enough to know the characteristic exponent of the Lévy process. The most time-consuming computational unit for simulating a random variable based on a known cumulative distribution function can be effectively implemented using neural networks and accelerated through parallel computing. Thus, on the one hand, the approach we propose is suitable for a wide class of Lévy models, on the other hand, it can be combined with machine learning methods.

Единственность решения в обратной задаче с переопределением повышенного типа для абстрактного дифференциального уравнения второго порядка

We consider a linear inverse problem for a second-order abstract differential equation in a Banach space. The inhomogeneous term of the equation does not depend on time and is unknown. At the initial moment of time, the standard Cauchy conditions are given. An additional condition is specified at the final moment of time. This is a value of the second derivative of the main evolutionary function. For the studied problem, a uniqueness criterion of a solution is established. It is expressed in spectral terms. A simple sufficient condition for the solution uniqueness is noted. An example of the inverse problem for Poisson’s equation in a cylindrical domain is considered.

Optimal Control of the Position of Moisture Transfer Sources in Porous Media

The paper proposes an approach for finding the optimal position of sources of known power for the quasi-linear Richards equation in a rectangular area. The Kirchhoff transformation is applied with the introduced scaling of coordinates and powers of submerged sources, which allows formulating a dimensionless problem. The task of this study is to find the position of submerged sources - such that the distribution of moisture at the final moment of time is close to the given values or the given target function.

Queer Spectrality and the Hope of Heterolingual Address

This article reads the final moment of Fatma Aydemir’s 2022 novel, Dschinns, as an instance of heterolingual address, which provides an alternative to the progressive logic of assimilation in both Germany and Turkey and the cyclicality of transgenerational trauma. Opening out onto the possibility of a forthcoming counter-address marked by queer spectrality, the novel prompts readers to engage in an open-ended process of community formation by rethinking their own modes of address and the myriad power structures that undergird them.

Charging characteristics of finned thermal energy storage tube under variable rotation

Solar photovoltaic-thermal (PVT) systems effectively offset the drawbacks of intermittent solar and low photovoltaic conversion efficiency. Thermal energy storage (TES) tanks of PVT systems with high charging efficiency and consistent thermal safety might achieve efficient utilization of solar energy for building. A new variable rotational strategy has been proposed to optimize the charging characteristics for TES tubes, taking into consideration the non-uniformity of melting. A series of simulations based on the volume-averaged model are conducted to investigate the thermal energy storage property of TES tubes under variable rotary mechanism. Qualitative and quantitative comparisons are made between variable rotation (ω = 1.5–0.5, 1.5–1.0, 1.5–2.0 rad·s−1), constant rotation (ω = 1.5 rad·s−1), and stationary systems. The focus of the comparison is melting efficiency, temperature distribution, and natural convection. The results indicate that rotation effectively shortens charging time, with a 57.62% and 15.73% reduction with variable rotary mechanisms of 1.5–1.0 rad·s−1 when compared with stationary and constant rotating tubes. Meanwhile, in the final moment, the greatest medium-temperature (55–65 °C) proportion of 90.58% and less low-temperature (25–55 °C) and high-temperature (65–70 °C) paraffin occupation of 4.67% and 4.75% could be obtained, reflecting the completed latent heat storage and stable thermal safety. The optimal variable rotation achieves improvements of 47.84% and 106.73% in time-integral Grashof number (Gr) and heat storage rate, compared with traditional stationary tubes.

COMPOSITION AND ARCHITECTONICS OF A WORK OF FICTION AS A CHARACTERISTIC OF THE AUTHOR’S STYLE. J. CHAUCER «THE CANTERBURY TALES»

COMPOSITION AND ARCHITECTONICS OF A WORK OF FICTION AS A CHARACTERISTIC OF THE AUTHOR’S STYLE. J. CHAUCER «THE CANTERBURY TALES»

DYC Design for Autonomous Distributed Drive Electric Vehicle Considering Tire Nonlinear Mechanical Characteristics in the PWA Form

This paper presents a novel direct yaw moment control (DYC) strategy for autonomous distributed drive electric vehicle (DDEV) to improve path-following driving stability under critical maneuvers. Due to the fact that the tire mechanical characteristics show highly nonlinear under those critical conditions, the piecewise affine (PWA) identification method is chosen in this work to model the tire nonlinear mechanical characteristics since it shows best model accuracy/simplicity compromise for system control design. On this basis, to properly reflect the coupling behaviors between longitudinal motion and lateral motion, the vehicle dynamics model which considers the tire nonlinear mechanical characteristics in the PWA form is established. By analyzing the phase plane of vehicle nonlinear model, a novel external yaw moment calculation method based on global fast terminal sliding mode (GFTSM) control method is applied to the upper layer of DYC architecture for eliminating the errors of yaw rate and sideslip angle. Then, different weight coefficients are allocated to obtain the final external yaw moment. In the lower controller, the optimal four-wheel torque is distributed according to a concise and accurate algorithm in which adaptive weight coefficients are considered. The simulation results verify the effectiveness of the proposed control strategy in improving the driving stability performance of autonomous DDEV against two other control strategies under three extreme conditions.

Filter Regularization Method for Inverse Source Problem of the Rayleigh–Stokes Equation

In this paper, we consider a problem of recovering a space-dependent source term for the Rayleigh–Stokes equation, where the additional data is the observation at a final moment $t = T$, which is ill-posed in the sense of Hadamard. Firstly, the uniqueness, ill-posedness and the conditional stability of inverse source problem is given. Next, we develop a filter regularization method to overcome the ill-posedness of the problem. Under reasonable a priori bound assumption about the source function, a Hölder-type error estimate of the regularized solution is proved for a priori regularization parameter choice rule. Furthermore, a logarithmic-type error estimate between the exact solution and the regularized solution is established based on a posteriori regularization parameter choice rule.

Failed supernova simulations beyond black hole formation

ABSTRACT We present an axisymmetric failed supernova simulation beyond black hole formation, for the first time with numerical relativity and two-moment multi-energy neutrino transport. To ensure stable numerical evolution, we use an excision method for neutrino radiation hydrodynamics within the inner part of black hole domain. We demonstrate that our excision method is capable of stably evolving the radiation hydrodynamics in dynamical black hole space–time. As a remarkable signature of the final moment of proto-neutron star (PNS), we find the emergence of high-energy neutrinos. Those high-energy neutrinos are associated with the PNS shock surface being swallowed by the central black hole and could be a possible observable of failed supernovae.

Modeling the behavior of the acetabular axis and the axis of the ischial tuberosities during the transition from a standing to a sitting position

Introduction The success of the treatment of patients with degenerative diseases of the spine and concomitant damage to the hip joint depends on the understanding of the biomechanics of movements in the spinal-pelvic segment. After a thorough analysis of the biomechanical processes occurring in the spine-pelvis system during the transition from a standing to a sitting position, it becomes clear that the acetabular axis of rotation of the pelvis in space is not the only one.The purpose of the study was to develop and test a virtual model of the pelvis to study the kinematics of the movement of the spinal-pelvic complex with a description of the emergence of the iscial axis of rotation by changing the position from standing to sitting.Materials and methods The problem was solved using the finite element method. The bones were modeled as absolutely rigid bodies. The main ligaments and muscles were modeled using finite element springs: elastic fragments with specified rheological characteristics. The study of contact interaction was carried out for pairs: "femoral head – acetabulum" and "ischial tuberosities - chair surface".Results A new axis of rotation was revealed, the ischial axis, which corresponded to the points of initial contact of the ischial tuberosities with the surface of the chair. The axis of the acetabulum rotated by 7.1° relative to the ischial axis and at the final moment shifted in the horizontal direction relative to the acetabular axis by 8.83 mm. The gap between the surfaces of the femoral head and the acetabulum was about 8 mm.Discussion The study shows that the pelvis rotates depending on the position around two axes: acetabular and ischial ones, hence it follows that the acetabular axis oscillates back and forth during ante- and retroversion, that is, it is non-static. Shortcomings of the model: 1) muscles and ligaments were modeled using FE springs, the end and beginning of which were set by two points, and the muscles and ligaments in the real body are attached along the entire surface of the bones; 2) soft tissues were not modeled in real volume. The merit of the study is the contact interaction of the pelvis with the chair and its rotation relative to the ischial axis, while other studies consider the rotation of the pelvis only relative to the acetabular axis.Conclusion A new axis of rotation arises due to the contact interaction of the pelvic bone with the surface of the chair when the skeleton moves from a standing position to a sitting position, the ischial axis. The gap between the surfaces of the femoral head and the acetabulum was about 8 mm. It is advisable to conduct a clinical study.