PDMS/PVA composite ferroelectret for improved energy harvesting performance

This paper address the PDMS ferroelectret discharge issue for improved long- term energy harvesting performance. The PDMS/PVA ferroelectret is fabricated using a 3D-printed plastic mould technology and a functional PVA composite layer is introduced. The PDMS/PVA composite ferroelectret achieved 80% piezoelectric coefficient d33 remaining, compared with 40% without the proposed layer over 72 hours. Further, the retained percentage of output voltage is about 73% over 72 hours

Distribution of Spectral Lags in Gamma Ray Bursts

Using the data acquired in the Time To Spill (TTS) mode for long gamma-ray bursts (GRBs) collected by the Burst and Transient Source Experiment on board the Compton Gamma Ray Observatory (BATSE/CGRO), we have carefully measured spectral lags in time between the low (25-55 keV) and high (110-320 keV) energy bands of individual pulses contained in 64 multi-peak GRBs. We find that the temporal lead by higher-energy gamma-ray photons (i.e., positive lags) is the norm in this selected sample set of long GRBs. While relatively few in number, some pulses of several long GRBs do show negative lags. This distribution of spectral lags in long GRBs is in contrast to that in short GRBs. This apparent difference poses challenges and constraints on the physical mechanism(s) of producing long and short GRBs. The relation between the pulse peak count rates and the spectral lags is also examined. Observationally, there seems to be no clear evidence for systematic spectral lag-luminosity connection for pulses within a given long GRB.Comment: 20 pages, 4 figure

Unlipogramest

Master eminent lipogrammatists are an enigma to most temperamental people, misinterpreting intentions to strain imagination\u27s limits. Spelling must represent an emotional game, not a permanent serious pursuit. Illustrations aren\u27t meant to tell us language as it appears in usage. Interesting, entertaining, strange, unsettling, sensational, gruesome, monstrous, mountainous, gargantuan interpretations are paramount

Design of a Flexible Control Platform and Miniature in vivo Robots for Laparo-Endoscopic Single-Site Surgeries

Minimally-invasive laparoscopic procedures have proven efficacy for a wide range of surgical procedures as well as benefits such as reducing scarring, infection, recovery time, and post-operative pain. While the procedures have many advantages, there are significant shortcomings such as limited instrument motion and reduced dexterity. In recent years, robotic surgical technology has overcome some of these limitations and has become an effective tool for many types of surgeries. These robotic platforms typically have an increased workspace, greater dexterity, improved ergonomics, and finer control than traditional laparoscopic methods. This thesis presents the designs of both a four degree-of-freedom (DOF) and 5-DOF miniature in vivo surgical robot as well as a software architecture for development and control of such robots. The proposed surgical platform consists of a two-armed robotic prototype, distributed motor control modules, custom robot control software, and remote surgeon console. A plug-in architecture in the control software provides the user a wide range of user input devices and control algorithms, including a numerical inverse kinematics solver, to allow intuitive control and rapid development of future robot prototypes. A variety of experiments performed by a surgeon at the University of Nebraska Medical Center were used to evaluate the performance of the robotic platform. Adviser: Shane Farrito

Design of a Flexible Control Platform and Miniature in vivo Robots for Laparo-Endoscopic Single-Site Surgeries

Minimally-invasive laparoscopic procedures have proven efficacy for a wide range of surgical procedures as well as benefits such as reducing scarring, infection, recovery time, and post-operative pain. While the procedures have many advantages, there are significant shortcomings such as limited instrument motion and reduced dexterity. In recent years, robotic surgical technology has overcome some of these limitations and has become an effective tool for many types of surgeries. These robotic platforms typically have an increased workspace, greater dexterity, improved ergonomics, and finer control than traditional laparoscopic methods. This thesis presents the designs of both a four degree-of-freedom (DOF) and 5-DOF miniature in vivo surgical robot as well as a software architecture for development and control of such robots. The proposed surgical platform consists of a two-armed robotic prototype, distributed motor control modules, custom robot control software, and remote surgeon console. A plug-in architecture in the control software provides the user a wide range of user input devices and control algorithms, including a numerical inverse kinematics solver, to allow intuitive control and rapid development of future robot prototypes. A variety of experiments performed by a surgeon at the University of Nebraska Medical Center were used to evaluate the performance of the robotic platform. Adviser: Shane Farrito

New variable separation approach: application to nonlinear diffusion equations

The concept of the derivative-dependent functional separable solution, as a generalization to the functional separable solution, is proposed. As an application, it is used to discuss the generalized nonlinear diffusion equations based on the generalized conditional symmetry approach. As a consequence, a complete list of canonical forms for such equations which admit the derivative-dependent functional separable solutions is obtained and some exact solutions to the resulting equations are described.Comment: 19 pages, 2 fig

Finite element formulae for internal forces of Bernoulli-Euler beams under moving vehicles

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