Rapid Prototyping of Functional Three-Dimensional Microsolenoids and Electromagnets by High-Pressure Laser Chemical Vapor Deposition

Three-dimensional laser chemical vapor deposition (3D-LCVD) is an emerging process which bridges the gap between various macro-scale rapid prototyping (RP) systems and microfabrication technologies. With the ability to deposit both metals and dielectrics 3D-LCVD may be used to prototype integrated electromechanical components from sub-micron to centimeter scales. This technological niche is increasingly important with the ever-decreasing size and sophistication of consumer and industrial products. The objective of this work was the development of functional microsolenoids and electromagnets, using 3D-LCVD as the primary fabrication tool. High-aspect-ratio microsolenoids have the potential to generate much greater magnetic-field densities than their thin-film counterparts,l and have many advantages when used as actuators in microelectromechanical systems (MEMS).2 3D-LCVD provides a means of fabricating such helical structures, with an ease unparalleled by any lithographic or rapid prototyping process.Mechanical Engineerin

Heat pipes for wing leading edges of hypersonic vehicles

Wing leading edge heat pipes were conceptually designed for three types of vehicle: an entry research vehicle, aero-space plane, and advanced shuttle. A full scale, internally instrumented sodium/Hastelloy X heat pipe was successfully designed and fabricated for the advanced shuttle application. The 69.4 inch long heat pipe reduces peak leading edge temperatures from 3500 F to 1800 F. It is internally instrumented with thermocouples and pressure transducers to measure sodium vapor qualities. Large thermal gradients and consequently large thermal stresses, which have the potential of limiting heat pipe life, were predicted to occur during startup. A test stand and test plan were developed for subsequent testing of this heat pipe. Heat pipe manufacturing technology was advanced during this program, including the development of an innovative technique for wick installation

Weighted Radon transforms for which the Chang approximate inversion formula is precise

We describe all weighted Radon transforms on the plane for which the Chang approximate inversion formula is precise. Some subsequent results, including the Cormack type inversion for these transforms, are also given

Implementation of advanced practice nursing for minor orthopedic injuries in the emergency care context – a non-inferiority study

Aims To evaluate the implementation of advanced practice nursing for patients with minor orthopedic injuries, including comparison of outcomes in relation to advanced practice nurse versus standard (physician-led) care models. Design A non-inferiority study was performed in an emergency department in Norway, where advanced practice nursing is in an initial stage of implementation. The non-inferiority design was chosen to test whether the new advanced practice nursing model does not compromise quality of care compared to the standard care model already in use. Methods Patients with minor orthopedic injuries were assessed and treated by either advanced practice nursing or standard (physician-led) care models. Participating patients were assigned to the professional available at presentation. In the nursing model, registered nurses worked at an advanced level/applied advanced practice nursing following in-house-training. Senior orthopedic specialists evaluated the diagnostic and treatment accuracy in both models. Data were collected in a tool developed for this study, from May to October, 2019. Results In total, 335 cases were included, of which 167 (49.9 %) were assessed and treated in the nursing model. Overall, correct diagnosis was found in 97.3 % (n = 326) of the cases, and correct treatment was found in 91.3 % (n = 306) of the cases. In comparison of missed diagnosis between advanced practice nurse and the standard (physician-led) care model showed inconclusive results (risk ratio: 0.29, 95% CI: 0.06-1.36). In comparison of treatment outcomes, the results showed that the advanced practice nursing model was non-inferior (risk ratio: 0.45, 95% CI: 0.21-0.97). Conclusion Advanced practice nursing care models can be used to diagnose and treat minor orthopedic injuries without compromising quality of care. Further implementation of the advanced practice nurse care model is encouraged

When Coordinating Finger Tapping to a Variable Beat the Variability Scaling Structure of the Movement and the Cortical BOLD Signal are Both Entrained to the Auditory Stimuli

Rhythmic actions are characterizable as a repeating invariant pattern of movement together with variability taking the form of cycle-to-cycle fluctuations. Variability in behavioral measures is atypically random, and often exhibits serial temporal dependencies and statistical self-similarity in the scaling of variability magnitudes across timescales. Self-similar (i.e. fractal) variability scaling is evident in measures of both brain and behavior. Variability scaling structure can be quantified via the scaling exponent (α) from detrended fluctuation analysis (DFA). Here we study the task of coordinating thumb-finger tapping to the beats of constructed auditory stimuli. We test the hypothesis that variability scaling evident in tap-to-tap intervals as well as in the fluctuations of cortical hemodynamics will become entrained to (i.e. drawn toward) manipulated changes in the variability scaling of a stimulus’s beat-to-beat intervals. Consistent with this hypothesis, manipulated changes of the exponent α of the experimental stimuli produced corresponding changes in the exponent α of both tap-to-tap intervals and cortical hemodynamics. The changes in hemodynamics were observed in both motor and sensorimotor cortical areas in the contralateral hemisphere. These results were observed only for the longer timescales of the detrended fluctuation analysis used to measure the exponent α. These findings suggest that complex auditory stimuli engage both brain and behavior at the level of variability scaling structures

Stride-time variability is related to sensorimotor cortical activation during forward and backward walking

Previous research has used functional near-infrared spectroscopy (fNIRS) to show that motor areas of the cortex are activated more while walking backward compared to walking forward. It is also known that head movement creates motion artifacts in fNIRS data. The aim of this study was to investigate cortical activation during forward and backward walking, while also measuring head movement. We hypothesized that greater activation in motor areas while walking backward would be concurrent with increased head movement. Participants performed forward and backward walking on a treadmill. Participants wore motion capture markers on their head to quantify head movement and pressure sensors on their feet to calculate stride-time. fNIRS was placed over motor areas of the cortex to measure cortical activation. Measurements were compared for forward and backward walking conditions. No significant differences in body movement or head movement were observed between forward and backward walking conditions, suggesting that conditional differences in movement did not influence fNIRS results. Stride-time was significantly shorter during backward walking than during forward walking, but not more variable. There were no differences in activation for motor areas of the cortex when outliers were removed. However, there was a positive correlation between stride-time variability and activation in the primary motor cortex. This positive correlation between motor cortex activation and stride-time variability suggests that forward walking variability may be represented in the primary motor cortex