Phase-stepping fiber-optic projected fringe system for surface topography measurements

A projected fringe interferometer for measuring the topography of an object is presented. The interferometer periodically steps the phase angle between a pair of light beams emanating from a common source. The steps are pi/2 radians (90 deg) apart, and at each step a video image of the fringes is recorded and stored. Photodetectors measure either the phase and theta of the beams or 2(theta). Either of the measures can be used to control one of the light beams so that the 90 deg theta is accurately maintained. A camera, a computer, a phase controller, and a phase modulator established closed-loop control of theta. Measuring the phase map of a flat surface establishes a calibration reference

Speckle interferometry using fiber optic phase stepping

A system employing closed-loop phase-stepping is used to measure the out-of-plane deformation of a diffusely reflecting object. Optical fibers are used to provide reference and object beam illumination for a standard two-beam speckle interferometer, providing set-up flexibility and ease of alignment. Piezoelectric fiber-stretchers and a phase-measurement/servo system are used to provide highly accurate phase steps. Intensity data is captured with a charge-injection-device camera, and is converted into a phase map using a desktop computer. The closed-loop phase-stepping system provides 90 deg phase steps which are accurate to 0.02 deg, greatly improving this system relative to open-loop interferometers. The system is demonstrated on a speckle interferometer, measuring the rigid-body translation of a diffusely reflecting object with an accuracy + or - 10 deg, or roughly + or - 15 nanometers. This accuracy is achieved without the use of a pneumatically mounted optics table

Future of smart cardiovascular implants

Cardiovascular disease remains the leading cause of death in Western society. Recent technological advances have opened the opportunity of developing new and innovative smart stent devices that have advanced electrical properties that can improve diagnosis and even treatment of previously intractable conditions, such as central line access failure, atherosclerosis and reporting on vascular grafts for renal dialysis. Here we review the latest advances in the field of cardiovascular medical implants, providing a broad overview of the application of their use in the context of cardiovascular disease rather than an in-depth analysis of the current state of the art. We cover their powering, communication and the challenges faced in their fabrication. We focus specifically on those devices required to maintain vascular access such as ones used to treat arterial disease, a major source of heart attacks and strokes. We look forward to advances in these technologies in the future and their implementation to improve the human condition

Lin28A induces energetic switching to glycolytic metabolism in human embryonic kidney cells

Background: Loss of a cell’s capacity to generate sufficient energy for cellular functions is a key hallmark of the ageing process and ultimately leads to a variety of important age-related pathologies such as cancer, Parkinson’s disease and atherosclerosis. Regenerative medicine has sought to reverse these pathologies by reprogramming somatic cells to a more juvenile energetic state using a variety of stem cell factors. One of these factors, Lin28, is considered a candidate for modification in the reprogramming of cellular energetics to ameliorate the ageing process while retaining cell phenotype. Results: Over-expression of Lin28A resulted in key changes to cellular metabolism not observed in wild-type controls. Extracellular pH flux analysis indicated that Lin28A over expression significantly increased the rate of glycolysis, whilst high resolution oxygen respirometry demonstrated a reduced oxygen consumption. Western blot and real-time PCR analysis identified Hexokinase II as one of the key modulators of glycolysis in these cells which was further confirmed by increased glucose transport. A metabolic switching effect was further emphasised by Western blot analysis where the oxygen consuming mitochondrial complex IV was significantly reduced after Lin28A over expression. Conclusions: Results from this study confirm that Lin28A expression promotes metabolic switching to a phenotype that relies predominantly on glycolysis as an energy source, while compromising oxidative phosphorylation. Mechanisms to augment regulated Lin28A in age related pathologies that are characterised by mitochondria dysfunction or in differentiated and aged post-mitotic cells is the future goal of this work

Performance characteristics of an isolated coannular plug nozzle at transonic speeds

The Langley 16-Foot Transonic Tunnel was used to evaluate the performance characteristics of a coannular plug nozzle at static conditions (Mach number of 0) and at Mach numbers from 0.65 to 1.20. Jet total pressure ratio was varied from 1.0 (jet off) to 10.0. Thirty-seven configurations generated by the combination of three geometric variables - plug angle, shroud boattail length (fixed exit radius), and shroud extension length - were tested

An image of communication: theories of imaging in cognitive psychology

Thesis (M.A.)--University of Oklahoma, 1994.Includes bibliographical references (leaves 35-36)In an empirical study, visual breakpoints were created from a motion video presentation. These were then used, along with the original motion video presentation , in a memory test experiment testing for recall of abstract information contained in the presentation narrative. Twenty subjects, undergraduate psychology students, marked the breakpoints. Next, thirteen subjects viewed a the presentation which contained only the still breakpoint frames. Fourteen students viewed the original, motion video presentation. Each group was given a recall test on the facts in the presentation narrative immediately after exposure and 48 hours later. TI1e breakpoints were graphed and analyzed for characteristics relevant to the visual media's tradition of the decisive moment. In addition, it was proposed four types of breakpoints could be identified. The memory test yielded no significant results. The hypothesis, that breakpoint subjects would perform better than motion subjects in a memory test remains unsupported

Small Satellite Missions for Planetary Science

The National Aeronautics and Space Administration’s Science Mission Directorate is committed to developing science missions based on small-format spacecraft, including CubeSats and those that can be launched from a standard evolved expendable launch vehicle (EELV) secondary payload adapter (ESPA) ring. This paper describes the investments in small-format spacecraft (SmallSats) that NASA’s Planetary Science Division has made to date, including nineteen concept studies used to determine if deep space SmallSat missions could credibly conduct high quality science. The results of those studies were used to solicit SmallSat missions under the Small Innovative Missions for Planetary Exploration (SIMPLEx) program. This paper describes these previous investments and the types of technologies needed to accomplish them, and describes the Planetary Science Division’s plans to continue developing these small but powerful missions

Japanese and American Education: A Comparative Study

While living in Japan as an exchange student, many different aspects of Japanese culture, especially the Japanese education system, fascinated me. Their system demanded so much from children and determined the paths their lives would take based upon two or three long and complicated tests. My college friends had obviously survived the rigors of the schools system and, as I eventually realized, succeeded. All of the publicity that Japanese education received in the United States as a model system made me curious to know whether the stories in magazines and on the 6 o\u27clock news held any truth or if the American public saw only the good side of Japanese education. I unwittingly began research on this project when I started asking questions of my teachers and friends in Japan and comparing their answers about Japanese education with my own experiences in the U.S. public school system and at Seinan University. This paper resulted from those questions, my own experiences, and my search at Seinan and Ouachita for the answers. My own education consists of attendance in a small rural school district with a white majority and Hispanic and Indian minorities. I received a lot of personal attention during my school career and I floated through high school rather smoothly. I did not learn to study until I started college and the work became more demanding. My education was the opposite of my Japanese friends. They had studied continuously in junior high and high school and in college they completely abandoned their former study habits. My classes at Seinan presented few challenges and opportunities other than writing letters to my friends in the United States. At the outset, I didn\u27t think that two mo;e different education systems could exist. This thesis explores the general systems and methods of American and Japanese education while focusing on specific areas that plague or build up education in two extremely different cultures in two countries that have become inextricably economically dependent upon each other. Both nations hold up the other\u27s school system as examples despite the problems inherent in both models. Neither system has achieved perfection, but Japan and the United States can help each other to improve upon their existing education systems