Design of wideband vibration-based electromagnetic generator by means of dual-resonator

This paper describes the design of a wideband electromagnetic energy harvester that utilizes a novel dual-resonator method to improve the operational frequency range of the vibration-based generator. The device consists of two separate resonator systems (coil and magnet), which each comply with their respective resonance frequencies. This is because both resonators are designed in such a way that both magnet and coil components will oscillate at an additive phase angle, and hence create greater relative motion between the two dominating resonance frequencies, which realizes the wideband generator. Each resonator system consists of a distinctive cantilever beam, one attached with four magnets and steel keepers, the other attached with a copper coil and stainless steel holder as the free end mass. Both cantilevers are clamped and fitted to a common base that is subjected to a vibration source. Basic analytical models are derived and a numerical model is implemented in MATLAB-Simulink. Electromagnetic, structural modal and static mechanical analysis for the design of the prototype are completed using ANSYS finite element tools. For a 0.8 m s−2 acceleration, the open-loop voltage obtained from the experiment shows a good correlation with those from the simulation. Peak induced voltage is measured to be 259.5Vrms as compared to 240.9Vrms from the simulator at 21.3 Hz, which implies an error range of 7.7%. The results also indicate that there is a maximum of 58.22% improvement in the induced voltage within the intermediate region which occurs at the intersection point between the output response plots of two single resonator generators

Analytical and finite-element study of optimal strain distribution in various beam shapes for energy harvesting applications

Due to the increasing demand for harvesting energy from environmental vibration, for use in self-powered electronic applications, cantilever-based vibration energy harvesting has attracted great interest from various parties and become one of the most common approaches to convert redundant mechanical energy into electrical energy. As the output voltage produces from a piezoelectric material depends greatly on the geometric shape and the size of the beam, there is a need to model and compare the performance of cantilever beams of differing geometries. This paper presents the study of strain distribution in various shapes of cantilever beams, including a convex and concave edge profile elliptical beams that have been overseen in most of the prior literature. Both analytical and finite element models are derived and the resultant strain distributions in the beam are computed based on MATLAB solver and ANSYS finite element analysis tools. An optimum geometry for a vibration-based energy harvester system is verified. Lastly, experimental results comparing the power density for a triangular and rectangular piezoelectric beams are also presented to validate the finding of the study and the claim as suggested in the literature is verified

BCHS 2524- Overview of Minority Health and Health Disparities in the US

Understanding health disparities involves a critical analysis of historical, political, economic, social, cultural, and environmental conditions that have produced an inequitable health status for racial and ethnic minorities in the United States. While we also recognize that disparities exist along socio-economic status, gender, sexual orientation and other factors, this class will focus on disparities in racial and ethnic minority communities. Issues of gender, SES and other factors will be examined as they intersect race and ethnicity, and further influence disparities in health. Minority health and health disparities have gained considerable attention from the recent publication of Healthy People 2010 Report, which lists as its two goals: 1) improve the quality of life for all citizens, and 2) eliminate health disparities. The purpose of this class is to introduce basic issues that underlie health disparities. We will gain a better understanding of the relationships of social and environmental phenomena and the health of minority communities. This course will include current literature and foster discussions that will examine health disparities, explore social and environmental determinants of those disparities, critically review measurement issues, and determine public health’s response to these disparities. Students should seek to critically reflect on their personal and professional roles in eliminating health disparities. By the end of the course, students will be able to

Overview of Minority Health and Health Disparities in the US

Understanding health disparities involves a critical analysis of historical, political, economic, social, cultural, and environmental conditions that have produced an inequitable health status for racial and ethnic minorities in the United States. While we also recognize that disparities exist along socio-economic status, gender, sexual orientation and other factors, this class will focus on disparities in racial and ethnic minority communities. Issues of gender, SES and other factors will be examined as they intersect race and ethnicity, and further influence disparities in health. Minority health and health disparities have gained considerable attention from the recent publication of Healthy People 2010 Report, which lists as its two goals: 1) improve the quality of life for all citizens, and 2) eliminate health disparities. The purpose of this class is to introduce basic issues that underlie health disparities. We will gain a better understanding of the relationships of social and environmental phenomena and the health of minority communities. This course will include current literature and foster discussions that will examine health disparities, explore social and environmental determinants of those disparities, critically review measurement issues, and determine public health’s response to these disparities. Students should seek to critically reflect on their personal and professional roles in eliminating health disparities. By the end of the course, students will be able to

Air Force Eastern Test Range Central Telemetry Station (TEL-IV)

We have had a vast increase in the amount and rate of data telemetered back to the Eastern Test Range from both missiles and manned and unmanned space vehicles over the past few years. In 1961, as a major part of the Eastern Test Range Telemetry Modernization Program, development of a new Central Telemetry Station at Kennedy Space Center was initiated. It was designated Telemetry Station IV (TEL-IV), The objectives of the new Central Telemetry Station (TEL-IV) have been established as: 1. Provide simultaneous multiple mission capability for both pre-launch and launch support. 2. Serve as a central telemetry station for receiving , processing, and distributing the telemetered data from remote mobile and landbased stations. 3. Provide minimum turn around time between mission setups and permit rapid equipment changes in the event of failures. 4. Provide real time and non - real time capability to meet all program requirements. In order to achieve these objectives, the integrated systems design departed from the traditional ground station concept of hard wire or manual patching. Instead, the station was designed .and based on a central control technique. The system setup and equipment assignment for a given mission\u27s support is accomplished automatically by a launch coordinator through a special purpose , wired-program digital data processor and a cross-bar switching network

Staying true with the help of others: doxastic self-control through interpersonal commitment

I explore the possibility and rationality of interpersonal mechanisms of doxastic self-control, that is, ways in which individuals can make use of other people in order to get themselves to stick to their beliefs. I look, in particular, at two ways in which people can make interpersonal epistemic commitments, and thereby willingly undertake accountability to others, in order to get themselves to maintain their beliefs in the face of anticipated “epistemic temptations”. The first way is through the avowal of belief, and the second is through the establishment of collective belief. I argue that both of these forms of interpersonal epistemic commitment can function as effective tools for doxastic self-control, and, moreover, that the control they facilitate should not be dismissed as irrational from an epistemic perspective

Stimulated Raman adiabatic passage analogs in classical physics

Stimulated Raman adiabatic passage (STIRAP) is a well established technique for producing coherent population transfer in a three-state quantum system. We here exploit the resemblance between the Schrodinger equation for such a quantum system and the Newton equation of motion for a classical system undergoing torque to discuss several classical analogs of STIRAP, notably the motion of a moving charged particle subject to the Lorentz force of a quasistatic magnetic field, the orientation of a magnetic moment in a slowly varying magnetic field, the Coriolis effect and the inertial frame dragging effect. Like STIRAP, those phenomena occur for counterintuitively ordered field pulses and are robustly insensitive to small changes in the interaction properties

Differential Expression Of Gap Junction mRNAs And Proteins In The Developing Murine Kidney And In Experimentally Induced Nephric Mesenchymes

The expression of three gap junction (GJ) proteins, alpha-1 (Cx43), beta-1 (Cx32), and beta-2 (Cx26), and their transcripts were examined during the ontogeny of the mouse and rat kidney. These proteins were expressed in two non-overlapping patterns. The alpha-1 GJ protein was first observed in mesenchymal cells in the 12-day mouse kidney. By day 14 and thereafter, the ai protein was detected in the transient S-shaped bodies, but not in the podocytes of the maturing glomeruli. After birth the antigen was retained in a small subset of secretory tubules.The beta-1 and beta-2 GJ proteins were similar in their developmental patterns. They were first detected in a small subset of secretory tubules in the subcortical zone of day 17 embryos. These tubules were identified by immunohistochemical markers to be proximal. At birth, practically all proximal tubules expressed the two antigens.This analysis of GJ proteins was consistent with the results of S1 nuclease protection assays showing that, while the alpha-1 mRNA appeared early during kidney development and declined around birth, the two beta mRNAs appeared later and became intensified during the last days of intrauterine development.In experimentally induced metanephric mesenchymes, a transient expression of the alpha-1 GJ protein was seen during the segregation of the tubular anlagen. beta-1 and beta-2 GJ proteins were not detected in such induced mesenchymes cultivated up to 7 days.These observations provide evidence for the cell-specific utilization of different GJ genes during different stages of kidney organogenesis. The alpha-1 gene is activated during the early segregation of the secretory tubule and might contribute to its compartmentalization, while the beta-1 and beta-2 gene products are not detected until advanced stages of development. The latter gene products might be correlated with the physiological activity of the proximal tubules in vivo, as they are not expressed in experimentally induced tubules detectable with markers for proximal tubules

Ant Clustering with Locally Weighting Ant Perception and Diversified Memory

Ant clustering algorithms are a robust and flexible tool for clustering data that have produced some promising results. This paper introduces two improvements that can be incorporated into any ant clustering algorithm: kernel function similarity weights and a similarity memory model replacement scheme. A kernel function weights objects within an ant’s neighborhood according to the object distance and provides an alternate interpretation of the similarity of objects in an ant’s neighborhood. Ants can hill-climb the kernel gradients as they look for a suitable place to drop a carried object. The similarity memory model equips ants with a small memory consisting of a sampling of the current clustering space. We test several kernel functions and memory replacement schemes on the Iris, Wisconsin Breast Cancer, and Lincoln Lab network intrusion datasets. Compared to a basic ant clustering algorithm, we show that kernel functions and the similarity memory model increase clustering speed and cluster quality, especially for datasets with an unbalanced class distribution, such as network intrusion

Dynamics of magnetic moments coupled to electrons and lattice oscillations

Inspired by the models of A. Rebei and G. J. Parker and A. Rebei et. al., we study a physical model which describes the behaviour of magnetic moments in a ferromagnet. The magnetic moments are associated to 3d electrons which interact with conduction band electrons and with phonons. We study each interaction separately and then collect the results assuming that the electron-phonon interaction can be neglected. For the case of the spin-phonon interaction, we study the derivation of the equations of motion for the classical spin vector and find that the correct behaviour, as given by the Brown equation for the spin vector and the Bloch equation, using the results obtained by D. A. Garanin for the average over fluctuations of the spin vector, can be obtained in the high temperature limit. At finite temperatures we show that the Markovian approximation for the fluctuations is not correct for time scales below some thermal correlation time $\tau_{Th}$. For the case of electrons we workout a perturbative expansion of the Feynman-Vernon functional. We find the expression for the random field correlation function. The composite model (as well as the individual models) is shown to satisfy a fluctuation-dissipation theorem for all temperature regimes if the behaviour of the coupling constants of the phonon-spin interaction remains unchanged with the temperature. The equations of motion are derived