Full and Model-Reduced Structure-Preserving Simulation of Incompressible Fluids

This thesis outlines the construction of several types of structured integrators for incompressible fluids. We first present a vorticity integrator, which is the Hamiltonian counterpart of the existing Lagrangian-based fluid integrator. We next present a model-reduced variational Eulerian integrator for incompressible fluids, which combines the efficiency gains of dimension reduction, the qualitative robustness to coarse spatial and temporal resolutions of geometric integrators, and the simplicity of homogenized boundary conditions on regular grids to deal with arbitrarily-shaped domains with sub-grid accuracy.

Both these numerical methods involve approximating the Lie group of volume-preserving diffeomorphisms by a finite-dimensional Lie-group and then restricting the resulting variational principle by means of a non-holonomic constraint. Advantages and limitations of this discretization method will be outlined. It will be seen that these derivation techniques are unable to yield symplectic integrators, but that energy conservation is easily obtained, as is a discretized version of Kelvin's circulation theorem.

Finally, we outline the basis of a spectral discrete exterior calculus, which may be a useful element in producing structured numerical methods for fluids in the future.

Dynamic full-range Fourier-domain optical coherence tomography using sinusoidal phase-modulating interferometry

We propose a technique for dynamic full-range Fourier-domain optical coherence tomography by using sinusoidal phase-modulating interferometry, where both the full-range structural information and depth-resolved dynamic information are obtained. A novel frequency-domain filtering algorithm is proposed to reconstruct a time-dependent complex spectral interferogram from the sinusoidally phase-modulated interferogram detected with a high-rate CCD camera. By taking the amplitude and phase of the inverse Fourier transform of the complex spectral interferogram, a time-dependent full-range cross-sectional image and depth-resolved displacement are obtained. Displacement of a sinusoidally vibrating glass cover slip behind a fixed glass cover slip is measured with subwavelength sensitivity to demonstrate the depth-resolved dynamic imaging capability of our system. (c) 2007 Society of Photo-Optical Instrumentation Engineers.

Full-range parallel Fourier-domain optical coherence tomography using sinusoidal phase-modulating interferometry

We demonstrate a full-range parallel Fourier-domain optical coherence tomography (FD-OCT) in which a tomogram free of mirror images as well as DC and autocorrelation terms is obtained in parallel. The phase and amplitude of two-dimensional spectral interferograms are accurately detected by using sinusoidal phase-modulating interferometry and a two-dimensional CCD camera, which allows for the reconstruction of two-dimensional complex spectral interferograms. By line-by-line inverse Fourier transformation of the two-dimensional complex spectral interferogram, a full-range parallel FD-OCT is realized. Tomographic images of two separated glass coverslips obtained with our method are presented as a proof-of-principle experiment.

Dynamic full-range Fourier-domain optical coherence tomography using sinusoidal phase-modulating interferometry

We propose a technique for dynamic full-range Fourier-domain optical coherence tomography by using sinusoidal phase-modulating interferometry, where both the full-range structural information and depth-resolved dynamic information are obtained. A novel frequency-domain filtering algorithm is proposed to reconstruct a time-dependent complex spectral interferogram from the sinusoidally phase-modulated interferogram detected with a high-rate CCD camera. By taking the amplitude and phase of the inverse Fourier transform of the complex spectral interferogram, a time-dependent full-range cross-sectional image and depth-resolved displacement are obtained. Displacement of a sinusoidally vibrating glass cover slip behind a fixed glass cover slip is measured with subwavelength sensitivity to demonstrate the depth-resolved dynamic imaging capability of our system. (c) 2007 Society of Photo-Optical Instrumentation Engineers.

Trajectory control based on discrete full-range dynamics

There has been an increasing interest in the use of mechanical dynamics, (e.g., assive, Elastic, And viscous dynamics) for energy efficient and agile control of robotic systems. Despite the impressive demonstrations of behavioural performance, The mechanical dynamics of this class of robotic systems is still very limited as compared to those of biological systems. For example, Passive dynamic walkers are not capable of generating joint torques to compensate for disturbances from complex environments. In order to tackle such a discrepancy between biological and artificial systems, We present the concept and design of an adaptive clutch mechanism that discretely covers the full-range of dynamics. As a result, The system is capable of a large variety of joint operations, including dynamic switching among passive, actuated and rigid modes. The main innovation of this paper is the framework and algorithm developed for controlling the trajectory of such joint. We present different control strategies that exploit passive dynamics. Simulation results demonstrate a significant improvement in motion control with respect to the speed of motion and energy efficiency. The actuator is implemented in a simple pendulum platform to quantitatively evaluate this novel approach.

A path integral approach to the full Dicke model with dipole-dipole interaction

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Path integral approach to the full Dicke model

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

TIMS measurements of full range of natural Ca isotopes with internally consistent fractionation correction

This study presents static measurements of the Ca isotopic composition of standard reference materials SRM 915 a/b on a Triton Plus™ thermal ionization mass spectrometer with a specially developed Faraday cup array allowing simultaneous measurement of 40Ca and 48Ca. The total amount of Ca in all analyses was kept < 1 µg. With this setup the measurement uncertainties were 0.06 ‰ for 40Ca/44Ca and 0.12 ‰ for 48Ca/40Ca. Measuring all isotopes simultaneously better allows to test the internal consistency of different Ca isotope abundances reported in the literature. The exponential law was observed to correct incompletely instrumental mass fractionation. An improved fractionation correction based on the exponential law is proposed. It changes the 40Ca/44Ca ratio of SRM 915a (corrected relative to 42Ca/44Ca = 0.31221; 48Ca/44Ca = 0.08871) from 47.1635 ± 0.0028 to 47.1649 ± 0.0047. The measurements of SRM 915b were performed with different analytical conditions (runs were prolonged till complete filament load depletion). Even if the 40Ca/44Ca ratio of SRM 915b, when corrected with the simple exponential law, appears different (47.1532 ± 0.0038) from that of SRM 915a, it becomes coincident (47.1613 ± 0.0028) when corrected with a second-order refinement. This supports the use of the improved exponential law to obtain internally consistent Ca isotope ratio for natural samples.

Refinery Nonconventional Feedstocks: Influence of the Coprocessing of Vacuum Gas Oil and Low Density Polyethylene in Fluid Catalytic Cracking Unit on Full Range Gasoline Composition

Gasoline coming from refinery fluid catalytic cracking (FCC) unit is a major contributor to the total commercial grade gasoline pool. The contents of the FCC gasoline are primarily paraffins, naphthenes, olefins, aromatics, and undesirables such as sulfur and sulfur containing compounds in low quantities. The proportions of these components in the FCC gasoline invariable determine its quality as well as the performance of the associated downstream units. The increasing demand for cleaner and lighter fuels significantly influences the need not only for novel processing technologies but also for alternative refinery and petrochemical feedstocks. Current and future clean gasoline requirements include increased isoparaffins contents, reduced olefin contents, reduced aromatics, reduced benzene, and reduced sulfur contents. The present study is aimed at investigating the effect of processing an unconventional refinery feedstock, composed of blend of vacuum gas oil (VGO) and low density polyethylene (LDPE) on FCC full range gasoline yields and compositional spectrum including its paraffins, isoparaffins, olefins, napthenes, and aromatics contents distribution within a range of operating variables of temperature (500–700 °C) and catalyst-feed oil ratio (CFR 5–10) using spent equilibrium FCC Y-zeolite based catalyst in a FCC pilot plant operated at the University of Alicante’s Research Institute of Chemical Process Engineering (RICPE). The coprocessing of the oil-polymer blend led to the production of gasoline with very similar yields and compositions as those obtained from the base oil, albeit, in some cases, the contribution of the feed polymer content as well as the processing variables on the gasoline compositional spectrum were appreciated. Carbon content analysis showed a higher fraction of the C9–C12 compounds at all catalyst rates employed and for both feedstocks. The gasoline’s paraffinicity, olefinicity, and degrees of branching of the paraffins and olefins were also affected in various degrees by the scale of operating severity. In the majority of the cases, the gasoline aromatics tended toward the decrease as the reactor temperature was increased. While the paraffins and iso-paraffins gasoline contents were relatively stable at around 5 % wt, the olefin contents on the other hand generally increased with increase in the FCC reactor temperature.

Full bridge model study of a passive aerodynamic flutter suppression system

Peer reviewed

Effects of changing from full range of motion to partial range of motion on squat kinetics

It is commonplace for people involved in recreational weight training to limit squat depth to lift heavier loads. This study compares differences in movement kinetics when squatting in the full range of motion (FROM) vs. partial range of motion (PROM). Ten men with a 1-year minimum of resistance training attended 4 sessions each comprising 4 sets of squats following one of FROM for 10 repetitions (FROM10) at an intensity of 67% 1 repetition maximum (1RM) FROM squat, PROM for 10 repetitions (PROM10) at 67% 1RM PROM squat, FROM for 5 repetitions (FROM5) at 83% FROM squat or PROM for 5 repetitions (PROM5) at 83% 1RM PROM squat. Movement velocity was not specified. Squat kinetics data were collected using an optical encoder. Differences between conditions were analyzed by repeated-measures analysis of variance and expressed as mean differences and standardized (Cohen) effect sizes with 95% confidence limits. The PROM5 power was substantially more than the PROM10 (98 W, -21 to 217; mean, lower and upper 95% confidence limits), FROM5 (168 W, 47-289), and FROM10 (255 W, 145-365). The force produced during PROM5 was substantially more than PROM10 (372 N, 254-490), FROM5 (854 N, 731-977), and FROM10 (1,069 N, 911-1227). The peak velocity produced during FROM10 was substantially more than FROM5 (0.105 m·s(-1), 0.044-0.166), PROM10 (0.246 m·s(-1), 0.167-0.325), and PROM5 (0.305 m·s(-1), 0.228-0.382). The FROM5 was substantially more than FROM10 (86 J, 59-113), PROM5 (142 J, 90-194), and PROM10 (211 J, 165-257). Therefore, either range of motion can have practical implications in designing resistance training programs depending on if the training goal is related to power and force development, maximizing work output or speed. Moderate-load PROM training, common among recreational weight trainers, is unlikely to provide higher movement kinetics.

Liderazgo de Rango Total: revisión teórica del modelo

En el ámbito organizacional es necesario interiorizar y aplicar conceptos que generen herramientas que hagan posible el adecuado funcionamiento de las empresas a efectos de generar mejores resultados, no sólo en términos monetarios sino también sociales y éticos. En la actualidad, el entendimiento de las situaciones, circunstancias y relaciones que se dan dentro de una empresa es un factor relevante para la implementación de estrategias y técnicas, en aras de aumentar la productividad y la eficiencia de las compañías. Es allí donde empieza a tomar importancia la presencia de un líder en la compañía que actúe como agente de cambio y sea considerado como un modelo a seguir capaz de enfrentar situaciones emergentes, tanto positivas como negativas y así generar un cambio, deseos de mejora, propuestas inspiradoras e innovadoras. Lo anterior con el fin de proponer nuevas estrategias que beneficien a todos los involucrados, para así lograr los objetivos proyectados, evitando al máximo los posibles riesgos en que se pueda incurrir. A lo largo de la revisión teórica se tratará el modelo del liderazgo de rango total como un tipo de liderazgo donde el líder es capaz de moldear los puntos de vista, las percepciones, las actitudes y las creencias de los seguidores. Lo anterior sin dejar a un lado los demás estilos de liderazgo que componen el modelo de liderazgo de rango total, el cual puede ser considerado e incluido como una variable interesante en la realización de estudios para analizar la existencia de la relación entre el estilo de liderazgo y los resultados organizacionales.

Leadership Styles, Behaviors, and Outcomes of Athletic Training Education Program Directors

Context: With the increase in athletic training education programs, the demand for a highly qualified faculty member to serve as program director (PD) and fill the multiple roles and responsibilities of the position has increased. A successful PD must possess leadership skills crucial for the evolving academic environment. Research suggests that educational leaders must provide both transactional and transformational leadership if athletic trainers are to secure a legitimate place as healthcare providers. Objective: To describe the leadership styles and behaviors of athletic training education PDs and to describe the associations between leadership style, behavior, outcome, and experience. Design: We will utilize a survey design to identify the leadership styles, behaviors, outcomes, and experiences of athletic training education PDs. Setting: On-line questionnaire. Participants: The population of this study will be limited to the academic PDs of the 360 accredited entry-level athletic training education programs in the United States. Intervention: The investigation will utilize the Multifactor Leadership Questionnaire (MLQ). The MLQ is a validated tool composed of 45 items that identify and measure key leadership and effectiveness behaviors shown to be strongly linked with both individual and organizational success. In addition to the leader, it is recommended that all persons working above, below, and directly at the same organizational level as the leader rate the leader. Raters evaluate how frequently, or to what degree, they have observed the leader engage in 32 specific behaviors. Main Outcome Measure(s): Statistical analysis will be utilized to describe the associations between leadership styles, behaviors, outcomes, and experiences.