Angular Freedom Research Articles

A Hybrid Transmitting Coil for Improving Angular Freedom of a Wireless Power Transfer System

A Hybrid Transmitting Coil for Improving Angular Freedom of a Wireless Power Transfer System

Development of an FEA program with full-size stiffness and mass matrices for dynamic analysis of high-rise buildings: A comparison with SAP2000

Computational methods used for estimation the effects of dynamic loading on buildings need to be developed and updated to ensure structural safety. A computer program, YAY2020-Dynamic was developed using the Matlab interpreter to calculate the effect of dynamic forces on planar structures. The program successfully estimated the impact of dynamic forces on structures. The main feature of the program is that it uses mass and stiffness matrices with both diagonal and non-diagonal elements. Furthermore, the developed program uses 12 × 12 matrices in shear formulations to include moment and rotation effects perpendicular to the plane. These features were not used in the literature and have not been studied on high-rise buildings before. Modal analysis (Eigen analysis) and time history analysis (Newmark analysis) are performed in the program for dynamic analysis of high-rise buildings. A special formulation is used to include angular and rotation freedom parameters in the mass and stiffness matrices of plate elements. These matrices were presented for the first time in this study as 12 × 12 matrices with diagonal and non-diagonal elements. The core principle of the program is to make more realistic modeling by considering as many mechanisms as possible, instead of making assumptions and neglecting some parameters that limit representing real behavior. To determine the performance of the developed program, two buildings (a 10-story and a 20-story) were examined. According to the results, YAY2020-Dynamic determined that the examined building models were more rigid and had fewer deformations than the estimated by SAP2000. Therefore, the use of YAY2020-Dynamic in design stages can help determine the required member strengths more precisely and choose the proper building materials while considering the safety factors.

Collapse of hybrid vector beam in Rb atomic vapor.

In recent years, many researchers have tried to control and design the collapsing behavior of light beams in nonlinear media. Vector beams coupling with spin and orbit angular momentum freedom have attracted more and more attention. In this Letter, we study the collapse of a hybrid vector beam (HVB) propagating through rubidium atomic vapor. First, the HVB collapses into filaments located at positions with linear polarization. As propagation distance in atomic vapor increases, the locations of the filaments switch from positions with linear polarization to those with circular polarization. In this process, the absorption of the medium plays an important role. Results indicate that the absorption can be used as a degree of freedom to modulate the filamentation. Furthermore, by analyzing the polarization angle of an elliptically polarized position on the transverse plane of the HVB, we demonstrate the evolution of polarization distribution of HVB during propagation. Such results could have application in manipulating other structured beams and could be potentially applied to realize optical switches or logic for information processing.

Evaluation of Surgical Freedom for One-and-a-Half Nostril, Mononostril, and Binostril Endoscopic Endonasal Transsphenoidal Approaches.

Objective This article determines which of the one-and-a-half nostril, mononostril, and binostril endoscopic endonasal transsphenoidal approaches provide a superior manipulation during surgery. Methods The three approaches were orderly performed on 10 silicon-injected cadaveric heads to quantitatively assess surgical freedom and attack angle for sella. Measurements were determined with a standardized method under neuronavigation system using data of computed tomography. Results The one-and-a-half nostril endoscopic transsphenoidal approach (OETA) offered superior exposed area than that of the mononostril approach (META), and similar to that of the binostril approach (BETA). For surgical freedom at anatomic targets, the OETA showed greater surgical flexibility at pituitary center, the right medial optic carotid recess (R-mOCR), the left mOCR, the medial intersection of the right cavernous internal carotid artery, and extension line of upper margin of the clivus (R-mICC) than those of the META, and similar to those of the BETA. For sagittal angle of attack to the R-mOCR, R-mICC, and L-mOCR, the OETA can provide better angular freedom for surgeon than that of the META, and similar to that of the BETA. The OETA had the same axial attack to the pituitary center with the BETA. The OETA and the META had limited surgical freedom at L-mICC, and both inferior to the BETA. Conclusion The OETA has similar exposed area, surgical freedom, and attack angle for most anatomic targets to the BETA without resecting contralateral nasal septal mucosa, and obviously superior to the META.

A Bio-Inspired Model for Precise Control of Nozzle End of a Fire Hose Through Remote Controlled Operation

Today, there are a few autonomous fire-fighting robots but the absolute autonomous decision making in places that involve discrete thinking is still unresolved. With remotely operated fire-fighting robots, this problem can be solved to an extent. The project involves use of a remote power source to reduce the weight of the robot and a bio-inspired design of the fire hose manipulator mimicking the elephant’s trunk using which the hose tip could be moved precisely up to 5° on every direction. The hose can be manipulated to direct the water towards the fire, using the live video feed from a camera and raspberry pi set up that are on board. The movement of the robot and the fire hose manipulator can be remotely operated using GUI interface. The response of the robot for various intensities of flame, the angular freedom of the manipulator and the projectile of water-flow were studied and calibrated for better performance.

Role of angular bending freedom in regulating thermal transport in polymers

Polymers, despite their desirable structural properties, suffer from low thermal conductivity, which restricts their use. Previous studies have indicated that the strong bond-stretching and angular-bending interactions along the chain are believed to have saturated the maximum achievable thermal conductivity in the along-the-chain direction. Contrary to this belief, our results show an improvement in thermal conductivity. By increasing the bond and angle potential, we studied the effect on the thermal conductivity of polyethylene using non-equilibrium molecular dynamics simulations. In comparison to restricting the bond stretching, we found that restricting angular bending freedom plays a crucial role in improving the thermal transport along the chain. We observed significant changes in the morphology of the polyethylene chains when the angle potential was increased. We also found a remarkable increase in the phonon group velocity accompanied by large shifts in the longitudinal acoustic branch of the dispersion curve. These results when coupled with the structural changes strongly support the argument that thermal conductivity can be controlled by restricting the angular bending freedom.

The rotational spectrum and potential energy surface of the Ar-SiO complex.

The rotational spectra of five isotopic species of the Ar-SiO complex have been observed at high-spectral resolution between 8 and 18 GHz using chirped Fourier transform microwave spectroscopy and a discharge nozzle source; follow-up cavity measurements have extended these measurements to as high as 35 GHz. The spectrum of the normal species is dominated by an intense progression of a-type rotational transitions arising from increasing quanta in the Si-O stretch, in which lines up to = 12 (∼14 500 cm-1) were identified. A structural determination by isotopic substitution and a hyperfine analysis of the Ar-Si17O spectrum both suggest that the complex is a highly fluxional prolate symmetric rotor with a vibrationally averaged structure between T-shaped and collinear in which the oxygen atom lies closer to argon than the silicon atom, much like Ar-CO. To complement the experimental studies, a full dimensional potential and a series of effective vibrationally averaged, two-dimensional potential energy surfaces of Ar + SiO have been computed at the CCSD(T)-F12b/CBS level of theory. The equilibrium structure of Ar-SiO is predicted to be T-shaped with a well depth of 152 cm-1, but the linear geometry is also a minimum, and the potential energy surface has a long, flat channel between 140 and 180°. Because the barrier between the two wells is calculated to be small (of order 5 cm-1) and well below the zero-point energy, the vibrationally averaged wavefunction is delocalized over nearly 100° of angular freedom. For this reason, Ar-SiO should exhibit large amplitude zero-point motion, in which the vibrationally excited states can be viewed as resonances with long lifetimes. Calculations of the rovibrational level pattern agree to within 2% with the transition frequencies of normal and isotopic ground state Ar-SiO, and the putative K a = ±1 levels for Ar-28SiO, suggesting that the present theoretical treatment well reproduces the salient properties of the intramolecular potential.

Geometrical product specifications. Datums and coordinate systems

The work is devoted to the relevant topic such as the technical products quality improvement due to the geometrical specifications accuracy. The research purpose is to ensure the quality indicators on the basis of the systematic approach to the values normalization and geometrical specifications accuracy in the workpiece coordinate systems in the process of design. To achieve the goal two tasks are completed such as the datum features classification according to the number of linear and angular freedom degrees constraints, called the datums informativeness, and the rectangular coordinate systems identification, materialized by workpiece datums sets. The datum features informativeness characterizes the datums functional purpose to limit product workpiece linear and angular degrees of freedom. The datum features informativeness numerically coincides with the kinematic pairs classes and couplings in mechanics. The datum features informativeness identifies the coordinate system without the location redundancy. Each coordinate plane of a rectangular coordinate system has different informativeness 3 + 2 + 1. Each coordinate axis also has different informativeness 4+2+Θ (zero). It is possible to establish the associated workpiece position with three linear and three angular coordinates relative to two axes with the informativeness 4 and 2. is higher, the more informativeness of the coordinate axis or a coordinate plane is, the higher is the linear and angular coordinates accuracy, the coordinate being plotted along the coordinate axis or plane. The systematic approach to the geometrical products specifications positioning in coordinate systems is the scientific basis for a natural transition to the functional dimensions of features position - coordinating dimensions and the size of the features form - feature dimensions of two measures: linear and angular ones. The products technical quality improving is possible due to the coordinate systems introduction materialized by datums sets in GPS standards and national standards. Standards on the datums and datums systems should cover all the geometrical specifications and all the processes of the products life cycle: designing, manufacturing, verification and exploitation.

Realization of Cascaded Frequency Conversions Using a Single GdxY1-xCOB Crystal

In the field of nonlinear optics, cascaded frequency conversion is an effective method to obtain a solid-state laser source in the short wavelength region. By far, the most famous and popular frequency conversion approach is cascaded third-harmonic-generation (THG), which is composed of two steps: a phase-matching (PM) second-harmonic-generation, followed by a PM sum-frequency-generation. Correspondingly, two nonlinear optical (NLO) crystals are required. Theoretically, THG could be realized by utilizing only one crystal, as long as the frequency conversion processes occur at similar PM orientations and the polarization matching problem is solved. In this paper, we realized this approach by using one GdxY1-xCOB crystal; an ultrawide angular acceptance was observed because the SHG process was noncritical phase matching, thereby providing the advantages of large angular acceptance and freedom from beam walk-off as the optimum PM approach in the NLO domain. Compared to the traditional cascaded THG configuration that requires two crystals, this configuration possesses the advantages of small volume, compactness, and low cost, all of which are favorable for practical applications.

Orientation-free and differentially pumped addition of a low-flux reactive gas beam to a surface analysis system.

We describe an example of a piecewise gas chamber that can be customized to incorporate a low flux of gas-phase radicals with an existing surface analysis chamber for in situ and stepwise gas-surface interaction experiments without any constraint in orientation. The piecewise nature of this gas chamber provides complete angular freedom and easy alignment and does not require any modification of the existing surface analysis chamber. In addition, the entire gas-surface system is readily differentially pumped with the surface chamber kept under ultra-high-vacuum during the gas-surface measurements. This new design also allows not only straightforward reconstruction to accommodate the orientation of different surface chambers but also for the addition of other desired features, such as an additional pump to the current configuration. Stepwise interaction between atomic oxygen and a highly ordered pyrolytic graphite surface was chosen to test the effectiveness of this design, and the site-dependent O-atom chemisorption and clustering on the graphite surface were resolved by a scanning tunneling microscope in the nm-scale. X-ray photoelectron spectroscopy was used to further confirm the identity of the chemisorbed species on the graphite surface as oxygen.

Structure organization and magnetic properties of microscale ferrogels: The effect of particle magnetic anisotropy.

The equilibrium structure and magnetic properties of a ferrogel object of small size (microferrogel(MFG)) are investigated by coarse-grained molecular dynamics. As a generic model of a microferrogel (MFG), a sample with a lattice-like mesh is taken. The solid phase of the MFG consists of magnetic (e.g., ferrite) nanoparticles which are mechanically linked to the mesh making some part of its nodes. Unlike previous models, the finite uniaxial magnetic anisotropy of the particles, as it is the case for real ferrogels, is taken into account. For comparison, two types of MFGs are considered: MFG-1, which dwells in virtually non-aggregated state independently of the presence of an external magnetic field, and MFG-2, which displays aggregation yet under zero field. The structure states of the samples are analyzed with the aid of angle-resolved radial distribution functions and cluster counts. The results reveal the crucial role of the matrix elasticity on the structure organization as well as on magnetization of both MFGs. The particle anisotropy, which plays insignificant role in MFG-1 (moderate interparticle magnetodipole interaction), becomes an important factor in MFG-2 (strong interaction). There, the restrictions imposed on the particle angular freedom by the elastic matrix result in notable diminution of the particle chain lengths as well as the magnetization of the sample. The approach proposed enables one to investigate a large variety of MFGs, including those of capsule type and to purposefully choose the combination of their magnetoelastic parameters.

Evaluation of surgical freedom for microscopic and endoscopic transsphenoidal approaches to the sella.

Microscopic and endoscopic transsphenoidal approaches to the sellar are well established. Surgical freedom is an important skull base principle that can be measured objectively and used to compare approaches. To compare the surgical freedom of 4 transsphenoidal approaches to the sella turcica to aid in surgical approach selection. Four transsphenoidal approaches to the sella were performed on 8 silicon-injected cadaveric heads. Surgical freedom was determined with stereotactic image guidance using previously established techniques. The results are presented as the area of surgical freedom and angular surgical freedom (angle of attack) in the axial and sagittal planes. Mean total exposed area surgical freedom for the microscopic sublabial, endoscopic binostril, endoscopic uninostril, and microscopic endonasal approaches were 102 ± 13, 89 ± 6, 81 ± 4, and 69 ± 10 cm2, respectively. The endoscopic binostril approach had the greatest surgical freedom at the pituitary gland and ipsilateral and contralateral internal carotid arteries (25.7 ± 5.4, 28.0 ± 4.0, and 23.0 ± 3.0 cm2) compared with the microscopic sublabial (21.8 ± 3.5, 21.3 ± 2.4, and 19.5 ± 6.3 cm2), microscopic endonasal (14.2 ± 2.7, 14.1 ± 3.2, and 16.3 ± 4.0 cm2), and endoscopic uninostril (19.7 ± 4.8, 22.4 ± 2.3, and 19.5 ± 2.9 cm2) approaches. Axial angle of attack was greatest for the microscopic sublabial approach to the same targets (14.7 ± 1.3°, 11.0 ± 1.5°, and 11.8 ± 1.1°). For the sagittal angle of attack, the endoscopic binostril approach was superior for all 3 targets (16.6 ± 1.7°, 17.2 ± 0.70°, and 15.5 ± 1.2°). Microscopic sublabial and endoscopic binostril approaches provided superior surgical freedom compared with the endonasal microscopic and uninostril endoscopic approaches. This work provides objective baseline values for the quantification and evaluation of future refinements in surgical technique or instrumentation.

Mechanical Properties of Graphene Nanowiggles

ABSTRACTIn this work we have investigated the mechanical properties and fracture patterns of some graphene nanowiggles (GNWs). Graphene nanoribbons are finite graphene segments with a large aspect ratio, while GNWs are nonaligned periodic repetitions of graphene nanoribbons. We have carried out fully atomistic molecular dynamics simulations using a reactive force field (ReaxFF), as implemented in the LAMPPS (Large-scale Atomic/Molecular Massively Parallel Simulator) code. Our results showed that the GNW fracture patterns are strongly dependent on the nanoribbon topology and present an interesting behavior, since some narrow sheets have larger ultimate failure strain values. This can be explained by the fact that narrow nanoribbons have more angular freedom when compared to wider ones, which can create a more efficient way to accumulate and to dissipate strain/stress. We have also observed the formation of linear atomic chains (LACs) and some structural defect reconstructions during the material rupture. The reported graphene failure patterns, where zigzag/armchair edge terminated graphene structures are fractured along armchair/zigzag lines, were not observed in the GNW analyzed cases.

Early Experience of Talonavicular Arthrodesis Using an Intraosseous Fix System

Talonavicular arthrodesis is generally recommended for treating isolated degenerative arthritis and deformities of this joint. In general, good results have been published in the literature; however, nonunion of the talonavicular joint still remains a factor, which can affect outcome. We report our first 4 cases of isolated talonavicular arthrodesis using a novel intraosseous device designed to increase the stability of fixation generated across this joint. The system takes advantage of an intraosseous titanium post introduced into the navicular, through which a lag screw can thereafter be oriented across the talar neck and body. Surgical exposure can be minimized and compression can be achieved using leverage of the entire navicular rather than through a small medial portion of the tuber, obtaining a more stable and rigid construct that facilitates fusion and has been designed to permit early mobilization. The device provides the option of creating either a fixed angle Morse taper lock at the postlag interface or a polyaxial design capable of greater angular freedom. Pearls with respect to preoperative planning and technique and early results and complications are reviewed.

Rattler model of the boson peak at silica surfaces

Recent experiments unveiled two new aspects of the low-energy excitation spectrum of silica glass--commonly termed as the "boson peak" region. The first is that at low temperature the silica surface exhibits a different, softer boson peak than the bulk. The second is a giant thermal blueshift of the surface boson peak frequency causing it to cross and overcome the bulk peak with increasing temperature. Here we present a simple lattice model that reproduces this behavior in all its aspects. Each site consists of rigid tetrahedral units softly connected so as to be able to rotate anharmonically as "rattlers" in their cages. As shown by simulations, the model dynamics exhibits a boson-like peak, which has lower frequency at the surface where rattlers have a weaker restoring force. Upon heating however the larger angular freedom of surface units allows them to rattle more than in the bulk, leading to a steeper frequency increase similar to experiment.

Quantized Vortex State in hcp Solid 4He

The quantized vortex state appearing in the recently discovered new states in hcp 4He since their discovery is discussed. Special attention is given to evidence for the vortex state as the vortex fluid (VF) state and its transition into the supersolid (SS) state. Its features are described. The historical expla- nations for the SS state in quantum solids such as solid 4He were based on the idea of Bose Einstein Condensation (BEC) of the imperfections such as va- cancies, interstitials and other possible excitations in the quantum solids which are expected because of the large zero-point motions. The SS state was proposed as a new state of matter in which real space ordering of the lattice structure of the solid coexists with the momentum space ordering of superfluidity. A new type of superconductors, since the discovery of the cuprate high Tc superconductors, HTSCs, has been shown to share a feature with the vortex state, involving the VF and vortex solid states. The high Tcs of these materials are being discussed in connection to the large fluctuations associated with some other phase transitions like the antiferromagnetic transition in addition to that of the low dimensionality. The supersolidity in the hcp solid 4He, in contrast to the new superconductors which have multiple degrees of freedom of the Cooper pairs with spin as well as angular momentum freedom, has a unique feature of possessing possibly only the momentum fluctuations and vortex ring excitations associated with the possible low dimensional fluctuations of the subsystem(s). The high onset temperature of the VF state can be understood by considering thermally excited low D quantized vortices and it may be necessary to seek low dimensional sub-systems in hcp He which are hosts for vortices.

Co/Pd]4–Co–Pd–NiFe spring magnets with highly tunable and uniform magnetization tilt angles

By varying the Pd thickness (tPd) from 0 to 8nm in [Co/Pd]4/Co/Pd(tPd)/NiFe exchange springs, we demonstrate (i) continuous tailoring of the exchange coupling between a [Co/Pd]4/Co layer with perpendicular anisotropy, and a NiFe layer with an in-plane easy axis, (ii) tuning of the NiFe out-of-plane magnetization angle from 20○ to 80○, and (iii) an up to two-fold increase in the NiFe damping. The partial decoupling also results in a highly uniform NiFe magnetization. These properties make [Co/Pd]4/Co/Pd(tPd)/NiFe spring magnets ideal candidates for use as tilted polarizers, by combining stable and well-defined spin directions of its carriers with a high degree of angular freedom.

Entropic benefit of a cross‐link in protein association

We introduce a method to estimate the loss of configurational entropy upon insertion of a cross-link to a dimeric system. First, a clear distinction is established between the loss of entropy upon tethering and binding, two quantities that are often considered to be equivalent. By comparing the probability distribution of the center-to-center distances for untethered and cross-linked versions, we are able to calculate the loss of translational entropy upon cross-linking. The distribution function for the untethered helices is calculated from the probability that a given helix is closer to its partner than to all other helices, the "Nearest Neighbor" method. This method requires no assumptions about the nature of the solvent, and hence resolves difficulties normally associated with calculations for systems in liquids. Analysis of the restriction of angular freedom upon tethering indicates that the loss of rotational entropy is negligible. The method is applied in the context of the folding of a ten turn helical coiled coil with the tether modeled as a Gaussian chain or a flexible amino acid chain. After correcting for loop closure entropy in the docked state, we estimate the introduction of a six-residue tether in the coiled coil results in an effective concentration of the chain to be about 4 or 100 mM, depending upon whether the helices are denatured or pre-folded prior to their association. Thus, tethering results in significant stabilization for systems with millimolar or stronger dissociation constants.

Vibrational structure of GDP and GTP bound to RAS: an isotope-edited FTIR study.

A complete vibrational description of the bonding of a ligand to a protein requires the assignment of both symmetric and antisymmetric vibrational modes. The symmetric modes of isotopically enriched enzyme-bound ligands can be obtained by Raman difference spectroscopy, but until now, the antisymmetric modes, which require IR difference spectroscopy, have not been generally accessible. We have developed the methodology needed to perform IR difference spectroscopy, assign the antisymmetric modes, and accurately describe bonding. The method is used to assess the bonding changes that occur as Mg.GDP and Mg.GTP move from solution into the active site of RAS. Binding to RAS opens the nonbridging, O--P--O angle of the gamma-phosphate of GTP by 2.7 degrees, yet the angular freedom (dispersion of the O--P--O angle) of the gamma-phosphate is comparable to that in solution. In contrast, the motion of the beta-phosphate of GDP is highly restricted, suggesting that it positions the gamma-phosphate for nucleophilic attack. The beta,gamma-bridging O-P bond of bound GTP is slightly weakened, being lengthened by 0.005 A in the active site, corresponding to a bond order decrease of 0.012 valence unit (vu). The observed binding changes are consistent with a RAS-mediated hydrolysis mechanism that parallels that for solution hydrolysis.

Modelling of forces in the human masticatory system with optimization of the angulations of the joint loads

Numerical models of the human masticatory system were constructed using algorithms which minimized non-linear functions of the muscle forces or the joint loads. However, the predicted solutions for isometric biting were critically dependent upon the modelled angular freedom of the joint loads. The most complete mathematical minimization of any objective function occurs when the joint load angles are predicted. However, the predictions have to be sensible in relation to the actual morphology of the joints. Therefore, the models were tested in terms of the angles of joint load predicted for a dry skull, using muscle vectors reconstructed from the geometry of the skull. The minimizations of muscle force were intrinsically incapable of predicting the angles of joint load. Such models must rely on constrained angles and this produces a restricted minimization and also an indeterminacy. In contrast, the minimizations of joint load predicted angles of joint load which varied appropriately with condylar position. The condylar movement was achieved with a positioning model which adjusted the angulation of the muscle vectors as the jaw was positioned. This model also generated the optimal sagittal shape of the articular eminence. Muscle predictions from the various models were not examined in detail, but the general nature of the predicted muscle force patterns was shown to be reasonable in some of the models and unreasonable in others. The results supported the hypothesis that the temporomandibular joint develops functionally to allow an approximate minimization of the joint loads during isomeric biting. This does not necessarily imply that the neurophysiological control is actually based on a minimization of joint load.