Molecular Emissions from Circumstellar Envelopes in the Presence of a Binary Companion

Following our previous work on the hydrodynamic simulations of the structure of circumstellar envelopes in the presence of a binary companion, in this paper we present the results of radiative transfer calculations for molecular emission line HC3N J=5 – 4 from these simulated circumstellar envelopes. We show that the molecular line emission traces closely the spiral pattern and the associated density enhancement induced by the presence of the binary companion. The molecular emission provides the spatial kinematics of the features within the envelope, which is valuable for estimating the orbital parameters of the binary system and for inferring the physical conditions of the gas within the envelope. We also show that the appearance of the molecular emission depends on the viewing angle resulting in a range of shapes from the spiral pattern to ring-like features, similar to that observed recently in a number of circumstellar envelopes at high angular resolution.

In Situ X-Ray Computed Tomography (CT) Investigation on Localized Deformation and Crack Damage Evolution in a Bimrock by Tracking Rock Blocks

Instability of rock mass with block-in-matrix-rocks (bimrocks) often poses a threat to the geological and ecological environment; thus, investigation of the localized deformation and crack damage evolution is critical to predict the bimrock hazards. In this work, triaxial compression testing on block-in-matrix-soils (bimsoils) with a rock block percentage of 40% (mass ratio) was performed under tomographic monitoring using an original experimental setup specially designed to match the 450 kV industrial x-ray Computerized Tomography (CT) apparatus. A series of 2D CT images were obtained by carrying out CT scanning at key points throughout the test and from different positions in the sample. The physical strain localization phenomenon was well investigated using the proposed Block Tracking Movement (BTM) method to track the trajectory of rock blocks during deformation. The distribution and morphology of cracks are strongly influenced by the interactions between the rock block and the soil matrix including the repeating contact and separation between them that finally results in the macroscopic pattern of cracking. The displacement vector analysis revealed the spatial kinematics of rock blocks during sample deformation and the associated localized band evolution, which was consistent with the macroscopic crack pattern observation. The cracks corresponding to the low-density regions in the bimrock sample further indicate the inhomogeneous pattern of localized deformation. The meso-structural changes and strain localization of the bimrock under triaxial deformation are discussed first by analyzing the rock block movement using x-ray CT data.

Soccer Ball Spatial Kinematics and Dynamics Simulation for Efficient Sports Analysis

The intelligent sports analysis requires exactly modeling the kinematics and dynamics of a soccer ball in a three-dimensional (3D) space. To address this problem, a 3D dynamic model of the soccer ball is developed to simulate the motion and capture the kinematics and dynamics performance. The model consists of three sub-models governed by the classic mechanics and formulated as time-dependent ordinary differential equations (ODEs). The simulations involve visualizing the ball traveling trajectory, which contains the instantaneous force information; and plotting the time-varying displacement and force curves. The model is validated by comparison of the results from this simulation and another theoretical calculation. A case study is presented to simulate the projectile motion of a soccer ball in a virtual environment. The spatial kinematics and dynamics results are obtained and analyzed. The results show the max projectile height and range, and kick force increase with the increase of the initial velocity. This research is significant to simulate the soccer ball motion for promoting the planning, evaluation, and optimization of trajectory.

3-Dimensional Physiologic Postural Range of the Mandible: A Computerized-Assisted Technique—A Case Study

Previous studies demonstrated that while the mandible assumes its resting position in space, antagonistic muscles should assume minimal muscle activity within a spatial range. This zone of mandibular rest has been mapped using physiologic parameters of muscle activity and incisal spatial kinematics. This case study expands on previous research by monitoring incisal and posterior jaw position and includes lateral pterygoid muscle activity, thus allowing for determining the spatial range including additional relevant coordinates and muscle activity. Four positions were evaluated: a maximum physiologic open position, a maximum physiologic closed position, physiologic rest position, and maximum physiologic protrusion position. Within the physiologic zone of rest formed by these 4 positions, the vertical and anterior borders of the envelope of function may be documented for the incisal and posterior mandible in true 3-dimensional fashion to assist the clinician in determining a physiologic interocclusal freeway space and vertical dimension of occlusion. Advantages and limitations are discussed.

Automated Procedures for Robust and Efficient Solution of Over-Constrained Multibody Dynamics

The basic steps of a computer-based methodology that generates optimized runtime algorithms to achieve robust, stable, and efficient solution of constrained, multibody dynamics are summarized. The concept of using processors operating in the background to improve many aspects of an executing program’s performance on arbitrary models is introduced. Among the many optimizing tasks, algorithm processors extract model topology from body and joint descriptions, set up recursive spatial kinematics and generalized dynamics algorithms, block-partition constraints and apply Gaussian elimination with complete pivoting to identify and change dependent and independent variable sets, convert constraints into row-reduced, echelon form, permute the constrained generalized equations to achieve stable and efficient solutions, and set up recursive sparse uncoupling and solve algorithms to minimize fills and operations count. To accomplish these tasks, processors assess model-specific algorithm requirements and use this information to generate source and destination memory pointer arrays and arrays of pointers to structures and optimized functions. In essence, they wire and rewire runtime algorithms as needed to maintain robust, stable, and efficient solutions throughout a simulation.

EVLA imaging of the water masers in the massive protostellar cluster NGC6334I

We have used the recently-upgraded Karl G. Jansky Very Large Array (VLA) in A-configuration to observe the water masers in the massive protostellar cluster NGC6334I with broad bandwidth and high spectral resolution. Four groups of maser spots are found. The two groups with the broadest velocity span (40 km/s) are towards the UCHII region and the hot core SMA1. The spatial kinematics of the SMA1 masers are consistent in sense and orientation with the large-scale CO outflow and appear to trace the base of the outflow from a protostar at the dust peak of SMA1. Additional masers at the southern end of SMA1 provide evidence for a second protostar. The highest intensity maser lies about 2″ north of SMA1. Interestingly, no water masers are seen on the equally impressive hot core SMA2. Finally, we have detected maser emission toward the enigmatic source SMA4, which shows no millimeter molecular lines despite having strong, compact submillimeter continuum and may trace another protostar.