Residual Moment Research Articles

Annealing Effect on the Physical Properties of La0.7Sr0.3MnO3 Thin Films Grown on Si Substrates Prepared by Chemical Solution Deposition Method

The LSMO films were prepared on Si substrates by chemical solution deposition method. The films were annealing in air and O2 atmosphere. All films have perfectly crystallized. Compared with the LSMO films annealing in air, the residual and saturation magnetic moment value were much lower for the films annealing in O2. The Tc of the LSMO films annealing in O2 is higher about 15 K than that annealing in air. The variation of magnetization and Tc with annealing in O2 is thus consistent with the change of Sr content and is almost certainly related to the Mn3+/Mn4+ ratio. The MR value is decreased with the increasing temperature. It is observed that the transport properties, both the resistivity and the magnetoresistance value, have similar variation behavior. It is because that the La(Sr) vacancies (δ > 0) are expected to have indirect perturb the conduction path. The resistivity and the MR value at 7 T of the both films are (0.145 Ω.cm, 59.3%), (0.208 Ω.cm, 60.0%), respectively.

In-orbit offline estimation of the residual magnetic dipole biases of the POPSAT-HIP1 nanosatellite

The nanosatellite POPSAT-HIP1 is a Cubesat-class spacecraft launched on the 19th of June 2014 to test cold-gas based micro-thrusters; it is, as of April 2015, in a low Earth orbit at around 600km of altitude and is equipped, notably, with a magnetometer. In order to increment the performance of the attitude control of nanosatellites like POPSAT, it is extremely useful to determine the main biases that act on the magnetometer while in orbit, for example those generated by the residual magnetic moment of the satellite itself and those originating from the transmitter.Thus, we present a methodology to perform an in-orbit offline estimation of the magnetometer bias caused by the residual magnetic moment of the satellite (we refer to this as the residual magnetic dipole bias, or RMDB). The method is based on a genetic algorithm coupled with a simplex algorithm, and provides the bias RMDB vector as output, requiring solely the magnetometer readings. This is exploited to compute the transmitter magnetic dipole bias (TMDB), by comparing the computed RMDB with the transmitter operating and idling.An experimental investigation is carried out by acquiring the magnetometer outputs in different phases of the spacecraft life (stabilized, maneuvering, free tumble). Results show remarkable accuracy with an RMDB orientation error between 3.6° and 6.2°, and a module error around 7%. TMDB values show similar coherence values.Finally, we note some drawbacks of the methodologies, as well as some possible improvements, e.g. precise transmitter operations logging. In general, however, the methodology proves to be quite effective even with sparse and noisy data, and promises to be incisive in the improvement of attitude control systems.

The Pharmaceutical Capping Process-Correlation between Residual Seal Force, Torque Moment, and Flip-off Removal Force.

The majority of parenteral drug products are manufactured in a glass vials with an elastomeric rubber stopper and a crimp cap. The vial sealing process is a critical process step during fill-and-finish operations, as it defines the seal quality of the final product. An adequate force to remove the flip-off button prior to usage is required to ensure product quality during storage and transportation until use. In addition, the complete crimp cap needs to be fixed in a tight position on the vial. In this study, we investigated the torque moment required to turn the crimp cap and the force required to remove the flip-off button of container closure system sealed with different capping equipment process parameters (having different residual seal force values).

Contributions of Joint Torques, Motion-dependent Term and Gravity to the Generation of Baseball Bat Head Speed

This study quantifies the dynamic contributions of joint torques, motion-dependent term, and gravity to the generation of baseball bat head speed. Baseball batting is considered one of the most difficult tasks in sports motions. The batter is required to increase the bat head speed within a short time and move the bat into the hitting point with proper timing. Based on multi-body dynamics, a high speed swing motion is caused by not only joint torques and gravity but also motion-dependent term (MDT). The MDT consisting of centrifugal force, Coriolis force and gyro moment shows the dynamic characteristics of multi-segment motion. Five collegiate baseball players participated in this experiment. They performed hitting a teed ball as strong as possible. The whole-body segments with bat were modelled as a system of sixteen-rigid linked segments, and anatomical constraint axes of the elbow, wrist, knee and ankle joints were modelled with geometrical constraint equations in order to consider the degree of freedom (DOF) of the joint. The equation of motion for the whole-body and bat was obtained by considering modelling errors, such as residual joint force and moment, and fluctuations in segment’ lengths and joint constraint axes. Kinetic data of each hand and each foot were obtained by using an instrumented bat equipped with 28 strain gauges and 3 force platforms, respectively. The dynamic contributions of the joint moments, the motion-dependent term and the gravity term to the bat head speed were derived from the time integration of the equation of motion for the system. The results show that motion-dependent term is the largest contributor to the bat head speed in the last quarter of the forward swing phase. The contributions of the gravity and modelling error terms show small values. Motion dependent term is main generating factor to the head speed at the ball impact in baseball batting motion.

Stabilization of the small spacecraft with electromagnetic actuator in the presence of a residual magnetic moment

Stabilization of the small spacecraft with electromagnetic actuator in the presence of a residual magnetic moment

Centrifuge modeling of batter pile foundations under sinusoidal dynamic excitation

Batter pile (or inclined pile) foundations are widely used in civil engineering structures. However, their behavior under dynamic loadings is not yet thoroughly understood. This paper presents an experimental work on the behavior of batter and vertical piles considering dynamic soil-pile-superstructure interactions. A series of dynamic centrifuge tests were performed using sinusoidal excitations. The influence of the base shaking (frequency content and amplitude) and of the height of the center of gravity of the superstructure is investigated. Seismic responses are analyzed considering the pile cap displacements and forces (total base shear, overturning and residual moments, axial forces). It is found that in certain cases batter piles play a beneficial role on the dynamic behavior of the pile foundation system. This novel experimental work provides an important database on the behavior of batter pile foundations under dynamic loadings.

Geometric, electronic, and magnetic structure ofFexOy+clusters

Correlation between geometry, electronic structure, and magnetism of solids is both intriguing and elusive. This is particularly strongly manifested in small clusters, where a vast number of unusual structures appear. Here, we employ density functional theory in combination with a genetic search algorithm $\mathrm{GGA}+U$ and a hybrid functional to determine the structure of gas phase ${\text{Fe}}_{x}{\text{O}}_{y}^{+/0}$ clusters. For ${\mathrm{Fe}}_{x}{\mathrm{O}}_{y}^{+}$ cation clusters we also calculate the corresponding vibration spectra and compare them with experiments. We successfully identify ${\mathrm{Fe}}_{3}{\mathrm{O}}_{4}^{+}, {\mathrm{Fe}}_{4}{\mathrm{O}}_{5}^{+}, {\mathrm{Fe}}_{4}{\mathrm{O}}_{6}^{+}, {\mathrm{Fe}}_{5}{\mathrm{O}}_{7}^{+}$ and propose structures for ${\mathrm{Fe}}_{6}{\mathrm{O}}_{8}^{+}$. Within the triangular geometric structure of ${\mathrm{Fe}}_{3}{\mathrm{O}}_{4}^{+}$, a noncollinear, ferrimagnetic, and ferromagnetic state are comparable in energy. ${\mathrm{Fe}}_{4}{\mathrm{O}}_{5}^{+}$ and ${\mathrm{Fe}}_{4}{\mathrm{O}}_{6}^{+}$ are ferrimagnetic with a residual magnetic moment of $1\phantom{\rule{0.28em}{0ex}}{\ensuremath{\mu}}_{\mathrm{B}}$ due to ionization. ${\mathrm{Fe}}_{5}{\mathrm{O}}_{7}^{+}$ is ferrimagnetic due to the odd number of Fe atoms. We compare the electronic structure with bulk magnetite and find ${\mathrm{Fe}}_{4}{\mathrm{O}}_{5}^{+}, {\mathrm{Fe}}_{4}{\mathrm{O}}_{6}^{+}, {\mathrm{Fe}}_{6}{\mathrm{O}}_{8}^{+}$ to be mixed valence clusters. In contrast, in ${\mathrm{Fe}}_{3}{\mathrm{O}}_{4}^{+}$ and ${\mathrm{Fe}}_{5}{\mathrm{O}}_{7}^{+}$, all Fe are found to be trivalent.

Gompertz-power series distributions

ABSTRACTIn this article, we introduce the Gompertz power series (GPS) class of distributions which is obtained by compounding Gompertz and power series distributions. This distribution contains several lifetime models such as Gompertz-geometric (GG), Gompertz-Poisson (GP), Gompertz-binomial (GB), and Gompertz-logarithmic (GL) distributions as special cases. Sub-models of the GPS distribution are studied in details. The hazard rate function of the GPS distribution can be increasing, decreasing, and bathtub-shaped. We obtain several properties of the GPS distribution such as its probability density function, and failure rate function, Shannon entropy, mean residual life function, quantiles, and moments. The maximum likelihood estimation procedure via a EM-algorithm is presented, and simulation studies are performed for evaluation of this estimation for complete data, and the MLE of parameters for censored data. At the end, a real example is given.

Effects of Temperature Levels and Concrete Cover Thickness on Residual Strength Characteristics of Fire Exposed Reinforced Concrete Beams

Reinforced concrete structures are often subjected to fire of various degrees. After fire if the structure does not collapse during the fire there is need for post-fire assessment of its structural integrity before the fate of the structure can be determined. With the knowledge of the temperature of the fire, thickness of concrete cover, residual strength of concrete and tensile strength of embedded reinforcement after fire exposure, we can predict the residual carrying capacity of the beams after fire. The experimental procedure involves some specimens of reinforcing steel bars (∅16mm) enclosed in varying concrete covers in concrete beams which were exposed to ISO 834 furnace temperatures for 2hrs. After fire, the steel bars were removed and tested for tensile strength characteristics and the reduction in strength trend compared with the current code predictions for stress strain relationship of hot-rolled reinforcing steels at elevated temperatures. The variation in the residual moment and shear capacities of the reinforced concrete beams with temperature were evaluated. The experimental residual strength index was found to be greater than the theoretical prediction in the code. The variation in cover thickness of concrete to embedded reinforcement in beams was also noticed to be of no significance to the post-fire tensile strength of the steel reinforcement if the fire temperature is below 700oC. Keywords: Post-fire, flexure, residual strength, concrete cover, tensile strength, iso834 fire.

Nature of itinerant ferromagnetism ofSrRuO3: A DFT+DMFT study

We have investigated the temperature (T)-dependent evolution of electronic structures and magnetic properties of an itinerant ferromagnet SrRuO3, employing the combined scheme of the density functional theory and the dynamical mean-field theory (DFT+DMFT). The inclusion of finite dynamical correlation effects beyond the DFT well describes not only the incoherent hump structure observed in the photoemission experiment but also the T-dependent magnetic properties in accordance with experiments. We have shown that the magnetization of SrRuO3 evolves with the Stoner behavior below the Curie temperature (Tc), reflecting the weak itinerant ferromagnetic behavior, but the local residual magnetic moment persists even above Tc, indicating the local magnetic moment behavior. We suggest that the ferromagnetism of SrRuO3 has dual nature of both weak and local moment limits, even though the magnetism of SrRuO3 is more itinerant than that of Fe.

Distributed inelasticity planar frame element with localized semi-rigid connections for nonlinear analysis of steel structures

A macro-element model with spread of inelasticity and localized nonlinear semi-rigid hinges is presented in this paper. The element is formulated through force-based approach. Spread of inelasticity along element length and section depth is captured by fiber discretization of monitoring sections, and introduction of localized connections enable representation of any type of linear or nonlinear semi-rigid (partially restrained) connection behavior along element length without any increase in number of degrees of freedom. The element is used in conjunction with corotational formulation for the capture of nonlinear geometric effects. The proposed element is used for the analysis of steel structures considering the presence of beam to column semi-rigid connections in this paper. For a true representation of the hysteretic energy dissipation characteristic of a beam to column connection a quadra-linear moment–rotation based model is implemented incorporating pinching, damage, the possibility of residual moment capacity and degradation of stiffness under various scenarios. The behavior is calibrated via experimental data available in the literature. Robustness and accuracy of the proposed element and hysteretic connection model are assessed through numerical and experimental data, and the importance of accurate modeling of cyclic behavior of semi-rigid connections is demonstrated through analysis of a steel moment resisting frame.

A thermodynamic framework for the evolution of damage in concrete under fatigue

A closed-form expression for the dual of dissipation potential is derived within the framework of irreversible thermodynamics using the principles of dimensional analysis and self-similarity. Through this potential, a damage evolution law is proposed for concrete under fatigue loading using the concepts of damage mechanics in conjunction with fracture mechanics. The proposed law is used to compute damage in a volume element when a member is subjected to fatigue loading. The evolution of damage from microcracking to macrocracking of the entire member is captured through a series of volume elements failing one after the other. The number of loading cycles to failure of the member is obtained as the summation of number of cycles to failure for each individual volume element. A parametric study is conducted to determine the effect of the size of the volume element on the model's prediction of fatigue life. A global damage index is also defined, and the residual moment carrying capacity of damaged beams is evaluated. Through a deterministic sensitivity analysis, it is found that the load range and maximum aggregate size are the most influencing parameters on the fatigue life of a plain concrete beam.

Correlations between residual limb length and joint moments during sitting and standing movements in transfemoral amputees.

Longer residual limb lengths provide an increased lever arm. Longer residual limbs may produce increased joint moments; the two may be correlated. These correlations have not been evaluated in transfemoral amputees during transitional movements. Correlations between residual limb length and involved side joint moment could contribute to justification supporting maximal residual limb length preservation. This study investigated possible correlations between hip or knee moment and residual limb length. Hip and knee joint moments were determined while 21 transfemoral amputees performed sitting and standing movements and then evaluated for correlation with residual limb length. Residual limb length was not correlated with either knee or involved side hip moments during sit to stand or stand to sit. Conversely, weak inverse correlations (p < 0.05) existed between sound hip moment magnitude and residual limb length. These correlations suggest that in community ambulating transfemoral amputees, longer residual limb length could decrease sound hip kinetic burden during transitional movement. Beyond correlations between residual limb length and sound hip transitional movement kinetics, there are other considerations in determining residual limb length during amputation. This study examines relationships between lower limb joint moments and residual limb length related to sit-to-stand and stand-to-sit activities. The results have implications for amputation surgery and rehabilitation.

Investigation of Estimation Methods for Time-varying Residual Magnetic Moment

Generally, the dominant attitude disturbance source for the low Earth orbit small satellites is the residual magnetic moment (RMM). The RMM should be estimated and compensated in orbit to increase the attitude estimation and control accuracy. Although the estimator is usually built with the assumption that these parameters are constant, the RMM changes with sudden shifts caused by the variations in the onboard electrical current. The estimator should quickly track these unobserved parameters in case of change and perform accurate estimation for the rest of the procedure. In this paper, we investigate applicability of the existing estimators, such as the particle filter, for the RMM estimation. We present the initial results for an extended Kalman particle filter (EKPF) based method which may be useful for improving the estimation accuracy and tracking capability.

Reverse Bending Research of Leveling on Plastic Hardening Material

In order to further study the relevance between the first and the second reserve bending in the process of parallel roller level of plastic hardening material. Roller level bending mechanical model is established based on hardening elastic-plastic material in accordance with the fundamental of engineering elastic-plastic mechanics. The stress relevance of the two reserve bending processes is described by analytical method and discussed out the changing process of residual stress distribution, moment and loading stress with the section bending process of the roller level. With this model it is demonstrated that moment ratio and curvature ration is not simple "M-C" relation any longer, but function related to the first curvature ratio, the second curvature ratio and hardening factors. It is theoretically proved the original curvature theory can not apply to multi-reserve bending leveling processes.Analytical results show that during the second reserve bending process, there are decreased elastic limit bending moment and the bending moment in leveling process but increased spring-back ratio. Considered hardening of the same material residual stress mean square deviation are 71.2 and 65.6, average rebound ratio are 0.49 and 0.43.

A-24 関節トルクの発揮様式を考慮した野球打撃動作の動力学的分析(バットスイング)

The purpose of this study was to quantify the contribution of the whole-body joint torques to the generation of evaluation values during baseball batting motion, such as bat head speed and angular motion of the lower trunk in consideration of the joint torque generating mode. The whole-body segments and bat were modeled as a system of sixteen-rigid linked segments, and constraint axes of the elbow, wrist, knee and ankle joints were modeled with anatomical constraint equations in order to consider the degree of freedom (DOF) of the joint. Each hand was considered to be connected with the bat through zero DOF joint. The equation of motion with respect to the whole-body and bat was obtained by considering modelling errors, such as, residual joint force and moment, and fluctuation of segment's length. The dynamic contributions of the joint moments, motion dependent term and gravity term to the bat head speed and angular motion of the lower trunk were derived from the equation of motion for the system. Furthermore, the joint torque was divided into two components, such as eccentric torque component, which shows negative sign of its torque power, and concentric torque component, which shows positive sign of its torque power. The results obtained in this study showed that 1) motion dependent term was the great contributor to the generation of bat head speed and 2) major contributors to the generation of the bat head speed, such as concentric components of knob-side shoulder abduction torque and torso joint rotational torque were quantified by considering main generating factor of motion dependent term.

G0300801 レーザー照射を受ける薄板の熱弾塑性解析(重ね照射時の温度条件が残留モーメントの分布に与える影響)

G0300801 レーザー照射を受ける薄板の熱弾塑性解析(重ね照射時の温度条件が残留モーメントの分布に与える影響)

282 レーザー照射を受ける薄板の熱弾塑性解析 : 重ね照射時の照射の進行方向と残留モーメントの分布の関係について

282 レーザー照射を受ける薄板の熱弾塑性解析 : 重ね照射時の照射の進行方向と残留モーメントの分布の関係について

Effect of initial tool-plate curvature on snap-through load of unsymmetric laminated cross-ply bistable composites

In this study, the effect of the initial curvature of a tool plate on the snap-through load of square cross-ply bistable composites was analyzed. The snap-through load is a function of the cured curvature and residual moment. In the curing process, both these physical quantities are affected by the initial tool-plate curvature. As a result, the snap-through load can also be changed by adjusting the initial tool-plate curvature. Then, for evaluating its effect on the snap-through load, a snap-through process was simulated by minimizing the total potential energy of the bistable composites through the Rayleigh–Ritz approximation method. The simulation results show that the snap-through load changes linearly with the initial tool-plate curvature. The simulation results are compared with those obtained experimentally and by a finite element analysis (FEA) in order to verify the pre-identified effect of the initial tool-plate curvature.

Inelastic lateral-torsional buckling capacity of corroded web opening steel beams using artificial neural networks

Steel beams are extensively used as main structural in various building infrastructures such as bridge girders. Steel structures are prone to suffer various types of damage as they get older. Corrosion may be one of the most important types of damage in ageing steel structures. In a pessimistic state, an area of opening may be created along the bottom zone of the beam's web due to corrosion. The existence of opening in the web of a beam can reduce the resistance of the beam to shear, bending or buckling. This study deals with the stability of damaged steel I-beams with web opening. A three-dimensional finite element (FE) model using ABAQUS for inelastic analysis of beams has been developed to assess the effect of web opening on the lateral-torsional buckling (LTB) capacity. Artificial neural network approach has also been employed to derive empirical formula for predicting the residual ultimate LTB moment of damaged steel I-beams using obtained FE results. It is found out that the proposed formula can acc...