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Wire electrical discharge machining (WEDM) is one of the promising methods to produce precision dies and machine tools. In the present work, die corner accuracy achievable through trim cutting operation has been analyzed in the presence of a higher wire lag arising due to the higher workpiece thickness, acute corner angle, and higher flushing nozzle height. The influence of the corner error (uncut area left between the actual profile and the desired profile) generated in the first cut (rough cut) on the considered responses, namely volume removal rate, corner accuracy, surface roughness, and dimensional shift, has been analyzed by setting three different parameters during the first cut of the trim cutting operation. It is established that the trim cutting operation is a superior strategy for improving die corner accuracy than the pulse parameter modification strategy. Nevertheless, the high pulse parameter setting in rough cut was preferred for achieving greater productivity while the low pulse parameter setting in rough cut was chosen to achieve better corner accuracy at the cost of lower productivity.

We examine a modified Sprott A system, one of the 17 chaotic systems without equilibria introduced by Jafari, Sprott, and Golpayegani (2013). For specific parameter values, the modified system exhibits invariant spheres. Using a stereographic map, we analyze the stability of the equilibria and demonstrate that all orbits, except for the unstable equilibrium, converge to the stable equilibrium. For other parameter values, the system has neither invariant spheres nor equilibria. Instead, the state space is foliated by tori.

The reservoir conditions in Block D are poor, with a high proportion of reserves in thin reservoirs and a low drilling rate of channel sand. To more accurately match the design of chemical flooding parameters for Class II and III reservoirs and improve the fitting accuracy, the inaccessible pore volume, residual resistance factor, and other key parameters are modified, the surfactant concentration is optimized, and the chemical flooding slug dosage for Class II and III reservoirs is determined. Additionally, the research on reservoir connectivity between wells and factors affecting injection capacity has been carried out, the classification and discrimination method of well groups with injection capacity has been established, and the injection concentration range of well areas with different injection capacities has been determined, which has a certain guiding significance for the later design and adjustment of similar block schemes.

The effective potential for the axial mode of gravitational wave on noncommutative Schwarzschild background is presented. Noncommutativity is introduced via deformed Hopf algebra of diffeomorphisms by means of a semi-Killing Drinfeld twist. The analysis is performed up to the first order in perturbation of the metric and noncommutativity parameter. This results in a modified Regge-Wheeler potential with the strongest differences in comparison to the classical Regge-Wheeler potential being near the horizon.

The evaluation of the Step-wise transient (SWT) method is verified by experiment simulation using Finite elements method (FEM) and true values of the specimen thermophysical parameters, which resulted in an input response. This is evaluated by fitting the analytical temperature function providing the initial guesses of the specimen parameter values. The accuracy of the results is increased by modifying the original analytical temperature function with another FEM calculation using these initial guesses. The computed temperature response in an numerical form is transformed into an analytical one, which can be used in fitting the input response. The obtained results are compared with true values and initial guesses. This procedure is conducted with specimens made from silicate glass and polymethylmethacrylate (PMMA).

Nanocomposites with polymer matrix offer excellent opportunities to explore new functionalities beyond those of conventional materials. TiO2, as a reinforcement agent in polymeric nanocomposites, is a viable strategy that significantly enhanced their mechanical properties. The size of the filler plays an essential role in determining the mechanical properties of the nanocomposite. A defining feature of polymer nanocomposites is that the small size of the fillers leads to an increase in the interfacial area compared to traditional composites. The interfacial area generates a significant volume fraction of interfacial polymer, with properties different from the bulk polymer even at low loadings of the nanofiller. This review aims to provide specific guidelines on the correlations between the structures of TiO2 nanocomposites with polymeric matrix and their mechanical properties. The correlations will be established and explained based on interfaces realized between the polymer matrix and inorganic filler. The paper focuses on the influence of the composition parameters (type of polymeric matrix, TiO2 filler with surface modified/unmodified, additives) and technological parameters (processing methods, temperature, time, pressure) on the mechanical strength of TiO2 nanocomposites with the polymeric matrix.

The energy of a spacecraft, relative to the primary body of the system, before and after a Powered Swing-By maneuver with an impulse applied during the close encounter with the secondary body is studied. The Powered Swing-By maneuver is a combination of the effect of the gravity of a celestial body and an impulse applied to the spacecraft during its passage by the periapsis of its orbit relative to the secondary body. This combination modifies the spacecraft's trajectory, changing its parameters and, consequently, its energy. The objective is to quantify the effect of different mass parameters on the optimum direction to apply the impulse and in the energy variation of this more complex maneuver. It is focused on the two-dimensional and elliptical maneuver. Optimum solutions for energy gains are presented.

Measurements of the Standard Model Higgs boson decaying into a bb¯ pair and produced in association with a W or Z boson decaying into leptons, using proton–proton collision data collected between 2015 and 2018 by the ATLAS detector, are presented. The measurements use collisions produced by the Large Hadron Collider at a centre-of-mass energy of s=13Te, corresponding to an integrated luminosity of 139fb-1. The production of a Higgs boson in association with a W or Z boson is established with observed (expected) significances of 4.0 (4.1) and 5.3 (5.1) standard deviations, respectively. Cross-sections of associated production of a Higgs boson decaying into bottom quark pairs with an electroweak gauge boson, W or Z, decaying into leptons are measured as a function of the gauge boson transverse momentum in kinematic fiducial volumes. The cross-section measurements are all consistent with the Standard Model expectations, and the total uncertainties vary from 30% in the high gauge boson transverse momentum regions to 85% in the low regions. Limits are subsequently set on the parameters of an effective Lagrangian sensitive to modifications of the WH and ZH processes as well as the Higgs boson decay into bb¯.

Identifying efficient pathways to control and modify the order parameter of a macroscopic phase in materials is an important ongoing challenge. One way to do this is via the excitation of a high-frequency mode that couples to the order, and this is the ultimate goal of the field of ultrafast phase transitions1,2. This is an especially interesting research direction in magnetism, where the coupling between spin and lattice excitations is required for magnetization reversal3,4. However, previous attempts5,6 have not demonstrated switching between magnetic states via resonant pumping of phonon modes. Here we show how an ultrafast resonant excitation of the longitudinal optical phonon modes in magnetic garnet films switches magnetization into a peculiar quadrupolar magnetic domain pattern, revealing the magneto-elastic mechanism of the switching. In contrast, the excitation of strongly absorbing transverse phonon modes results in a thermal demagnetization effect only.Resonant excitation of phonons by a laser pulse switches the magnetization of a thin yttrium iron garnet film. This particular combination of longitudinal optical phonons results in a quadrupolar pattern, but this could be tailored in the future.

Molecular dynamics (MD) simulation is a valuable tool for characterizing the structural dynamics of folded proteins and should be similarly applicable to disordered proteins and proteins with both folded and disordered regions. It has been unclear, however, whether any physical model (force field) used in MD simulations accurately describes both folded and disordered proteins. Here, we select a benchmark set of 21 systems, including folded and disordered proteins, simulate these systems with six state-of-theart force fields, and compare the results to over 9,000 available experimental data points. We find that none of the tested force fields simultaneously provided accurate descriptions of folded proteins, of the dimensions of disordered proteins, and of the secondary structure propensities of disordered proteins. Guided by simulation results on a subset of our benchmark, however, we modified parameters of one force field, achieving excellent agreement with experiment for disordered proteins, while maintaining state-of-the-art accuracy for folded proteins. The resulting force field, a99SB-disp, should thus greatly expand the range of biological systems amenable to MD simulation. A similar approach could be taken to improve other force fields.