Sensorless torque estimation in multidegree-of-freedom flexible systems

This paper presents a sensorless torque estimation algorithm for multidegree-of-freedom flexible systems. The proposed algorithm makes it possible to estimate externally applied torques due to flexible system s interaction with the environment without taking any measurement from the system. The algorithm is based on modifying the disturbance observer in order to decouple the reflected torque waves out of the total disturbance on the actuator. Then Reflected torque waves are used along with the actuator s current and velocity to estimate flexible system parameters, dynamics and the external torques or disturbances. Several experimental results are included in order to confirm the validity of the proposed torque estimation algorithm

Constraints on Dark Photon from Neutrino-Electron Scattering Experiments

A possible manifestation of an additional light gauge boson $A^\prime$, named as Dark Photon, associated with a group $U(1)_{\rm B-L}$ is studied in neutrino electron scattering experiments. The exclusion plot on the coupling constant $g_{\rm B-L}$ and the dark photon mass $M_{A^\prime}$ is obtained. It is shown that contributions of interference term between the dark photon and the Standard Model are important. The interference effects are studied and compared with for data sets from TEXONO, GEMMA, BOREXINO, LSND as well as CHARM II experiments. Our results provide more stringent bounds to some regions of parameter space.Comment: 22 pages, 6 figures, 2 tables, text improved, fig.6 updated, references adde

Magnetoelectric and HR-STEM investigations on eutectic CoFe₂O₄-Ba_1-xSr_xTiO₃ composites

Multiferroic Ba1–xSrxTiO3–CoFe2O4 (x = 0.03, 0.05) composites with rarely investigated 3-3 connectivity were prepared by eutectic crystallization in an optical floating zone furnace. High-resolution scanning transmission electron microscopy investigations of the CoFe2O4–BaTiO3 interface revealed an almost perfect connection between both components. These micrographs also showed that the impact of post-annealing in air was much larger than expected and resulted in formation of small BaTiO3 inclusions in the CoFe2O4 phase. The magnetoelectric coefficient αME was studied in detail with respect to its dependence on the static magnetic field, the frequency of the driving AC-field and temperature. Furthermore, the influence of different growth rates (5, 10 and 20 mm h-1), chemical composition, sample thickness and the alignment of electrical polarization and magnetic field (collinear or vertical) on the magnetoelectric properties were studied. The largest value of αME = 1.3 mV Oe-1 cm-1 was found for a sample grown at 5 mm h-1. For even slower growth rates, a higher Sr content was required to avoid the formation of impurity phases leading to a decrease of αME

Finite Temperature Depinning of a Flux Line from a Nonuniform Columnar Defect

A flux line in a Type-II superconductor with a single nonuniform columnar defect is studied by a perturbative diagrammatic expansion around an annealed approximation. The system undergoes a finite temperature depinning transition for the (rather unphysical) on-the-average repulsive columnar defect, provided that the fluctuations along the axis are sufficiently large to cause some portions of the column to become attractive. The perturbative expansion is convergent throughout the weak pinning regime and becomes exact as the depinning transition is approached, providing an exact determination of the depinning temperature and the divergence of the localization length.Comment: RevTeX, 4 pages, 3 EPS figures embedded with epsf.st

Evaluation of the morphological characteristic and sex differences of sternum by multi-detector computed tomography

Background: Sternum is one of the skeleton parts which have frequently congenital anomalies and variations are commonly used by researchers in determining sex. We evaluated the morphological characteristics and sex-related changes of the sternum in adult individuals using multidetector computed tomography inour study.Materials and methods: Two hundred adults (103 female and 97 male) aged between 18 and 87 years were evaluated. Utilising the morphological characteristics of the sternum based on the multislice images; length, width and the thickness of manubrium, length, width and the thickness of corpus sterni, total length of sternum, sternal angle, sternal index (SI), length of the xiphoid process, the thickness of xiphoid process, the number of indents of xiphoid process were measured and a total of 20 parameters were evaluated by adding age, heightand weight to these variables.Results: The mean length of the manubrium, the length of corpus sterni, the length of total sternum, SI, sternal angle were found in females 46.7 ± 5.1, 86.6 ± 9.7, 133.1 ± 1.1, 54.47 ± 10.0 and 163.75 ± 5.79; in males 51.2 ± 6,102.4 ± 13.3, 154.1 ± 13.1, 50.11 ± 10.02 and 162.21 ± 6.17, respectively. We found that Hyrtl’s Law and SI did not provide adequate accuracy for sex determination in our patients. It has been detected that the length of the manubrium alone is not helpful for individual samples. Total length of the sternum was found to bemore reliable than the length of the manubrium and the length of corpus sterni. We determined sternal cleft and sternal foramen as 0.5% and 3.5%, respectively.Conclusions: We suggest that the morphometric standards cannot be universally applied and can demonstrate individual differences. The standard rules must be implemented for every population

Probabilistic Seismic Loss Estimation for Eskisehir, Turkey

Stochastic methods are utilized for the assessment of seismic hazard for the Eskisehir region. A comprehensive earthquake catalog, in which earthquakes in different scales are converted to a common scale, is compiled. Seismic source zones near the region with revised boundaries and various attenuation relationships are employed. Uncertainties related to the seismicity parameters and different assumptions are taken into consideration by using the logic tree procedure. Seismic hazard maps in terms of peak ground acceleration and MSK intensity, corresponding to a return period of 475 years are developed for Eskisehir. At the end of the study, the expected earthquake damage is estimated for the 31 districts located in Odunpazari, which is a municipality of Eskisehir

Coherency in Neutrino-Nucleus Elastic Scattering

Neutrino-nucleus elastic scattering provides a unique laboratory to study the quantum mechanical coherency effects in electroweak interactions, towards which several experimental programs are being actively pursued. We report results of our quantitative studies on the transitions towards decoherency. A parameter ($\alpha$) is identified to describe the degree of coherency, and its variations with incoming neutrino energy, detector threshold and target nucleus are studied. The ranges of $\alpha$ which can be probed with realistic neutrino experiments are derived, indicating complementarity between projects with different sources and targets. Uncertainties in nuclear physics and in $\alpha$ would constrain sensitivities in probing physics beyond the standard model. The maximum neutrino energies corresponding to $\alpha$>0.95 are derived.Comment: 5 pages, 4 figures, 3 tables. V2 -- Published Versio

Constraints on Non-Commutative Physics Scale with Neutrino-Electron Scattering

Neutrino-electron scatterings ($\nu - e$) are purely leptonic processes with robust Standard Model (SM) predictions. Their measurements can therefore provide constraints to physics beyond SM. Non-commutative (NC) field theories modify space-time commutation relations, and allow neutrino electromagnetic couplings at the tree level. Their contribution to neutrino-electron scattering cross-section was derived. Constraints were placed on the NC scale parameter $\Lambda_{NC}$ from $\nu - e$ experiments with reactor and accelerator neutrinos. The most stringent limit of $\Lambda_{NC} > 3.3 TeV$ at 95% confidence level improves over the direct bounds from collider experiments.Comment: 6 pages, 2 figures, 2 tables, V2: minor revisions to match published versio

A Ball in a Groove

We study the static equilibrium of an elastic sphere held in a rigid groove by gravity and frictional contacts, as determined by contact mechanics. As a function of the opening angle of the groove and the tilt of the groove with respect to the vertical, we identify two regimes of static equilibrium for the ball. In the first of these, at large opening angle or low tilt, the ball rolls at both contacts as it is loaded. This is an analog of the "elastic" regime in the mechanics of granular media. At smaller opening angles or larger tilts, the ball rolls at one contact and slides at the other as it is loaded, analogously with the "plastic" regime in the mechanics of granular media. In the elastic regime, the stress indeterminacy is resolved by the underlying kinetics of the ball response to loading.Comment: RevTeX 3.0, 4 pages, 2 eps figures included with eps