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131.
Improvement of 19F MR image uniformity in a mouse model of cellular therapy using inductive coupling
Park Bu S. Ma Ge Koch William T. Rajan Sunder S. Mastromanolis Manuel Lam Johnny Sung Kyung McCright Brent 《Magma (New York, N.Y.)》2019,32(1):15-23
Magnetic Resonance Materials in Physics, Biology and Medicine - Improve 19F magnetic resonance imaging uniformity of perfluorocarbon (PFC)-labeled cells by using a secondary inductive resonator... 相似文献
132.
133.
Brent M. Wilson Donald L. Johnson Hans Van Tilburg Matthew A. Russell Larry E. Murphy James D. Carr Robert J. De Angelis David L. Conlin 《JOM Journal of the Minerals, Metals and Materials Society》2007,59(10):14-18
The assessment of corrosion on the USS Arizona included the pioneering development of a minimum-impact cost-effective technique
to determine the corrosion rate of steel-hulled shipwrecks in seawater. The technique, with potential application worldwide,
is illustrated in this paper with the application to a World War II Japanese midget submarine submerged in deep waters off
the Oahu, Hawaii, coast. 相似文献
134.
The fixation of cells of petiolar hairs of tomato was monitored by phase contrast and Nomarski interference contrast microscopy. Because the cuticle covering these hairs is relatively impermeable some fixatives enter only the base of the hair so that a ‘fixation front’ can be followed through a single cell. The basal end of such a cell may be immobilized by the fixative while the apical end is still streaming. A variety of fixatives were tested at room temperature and at 273–278 K. All procedures tested failed to stabilize a pleomorphic canalicular system that is a dominant feature of these cells so that no clue to the presence of this system can be seen in sectioned material. It is therefore very desirable that images of fixed cells be compared to the structure of similar cells which are still alive. 相似文献
135.
Brent J. Maundy Ahmed S. Elwakil Domenico Zito 《International Journal of Circuit Theory and Applications》2019,47(1):175-185
We propose a novel CMOS differential voltage-controlled equivalent active resistor based on a modified common-source cross-coupled pair. The equivalent resistance exhibited by the circuit can be tuned to be either positive or negative through the tail current, which is controlled by a bias voltage. The complete cell comprises four transistors, two resistors in addition to the bias voltage, and tail current source. Application to the design of oscillators is demonstrated by theoretical analysis, circuit simulations, and verified experimentally through measurements on prototypes implemented using discrete transistors. 相似文献
136.
Roadmapping the Technological Future of Electricity 总被引:1,自引:0,他引:1
A future-scanning collaboration orchestrated by the Electric Power Research Institute has sought to illuminate the technologies whose development will be needed to attain the “2 percent” solution of improvements in economic productivity, energy efficiency and agricultural productivity necessary for global sustainability. 相似文献
137.
138.
Alexander Giovannitti Reem B. Rashid Quentin Thiburce Bryan D. Paulsen Camila Cendra Karl Thorley Davide Moia J. Tyler Mefford David Hanifi Du Weiyuan Maximilian Moser Alberto Salleo Jenny Nelson Iain McCulloch Jonathan Rivnay 《Advanced materials (Deerfield Beach, Fla.)》2020,32(16):1908047
Avoiding faradaic side reactions during the operation of electrochemical devices is important to enhance the device stability, to achieve low power consumption, and to prevent the formation of reactive side-products. This is particularly important for bioelectronic devices, which are designed to operate in biological systems. While redox-active materials based on conducting and semiconducting polymers represent an exciting class of materials for bioelectronic devices, they are susceptible to electrochemical side-reactions with molecular oxygen during device operation. Here, electrochemical side reactions with molecular oxygen are shown to occur during organic electrochemical transistor (OECT) operation using high-performance, state-of-the-art OECT materials. Depending on the choice of the active material, such reactions yield hydrogen peroxide (H2O2), a reactive side-product, which may be harmful to the local biological environment and may also accelerate device degradation. A design strategy is reported for the development of redox-active organic semiconductors based on donor–acceptor copolymers that prevents the formation of H2O2 during device operation. This study elucidates the previously overlooked side-reactions between redox-active conjugated polymers and molecular oxygen in electrochemical devices for bioelectronics, which is critical for the operation of electrolyte-gated devices in application-relevant environments. 相似文献
139.
A Galerkin finite element solution is developed for the flow of fiber suspensions. Primary variables are velocity, pressure, and a second‐order tensor describing the fiber orientation. The model treats the orientation as three‐dimensional, includes fiber—fiber interaction effects, and uses an orthotropic closure approximation. The flow and orientation are strongly coupled through an orientation‐dependent constitutive equation. We explore the effect of this coupling on the fluid mechanics of fiber suspensions by studying three flows: an axisymmetric contraction, an axisymmetric expansion, and a center‐gated disk. Coupling enhances the corner vortex in the contraction, in quantitative agreement with published experiments and calculations. The expansion results demonstrate that the aligned‐fiber approximation is not valid for this flow. In the center‐gated disk the effects of coupling are modest and are only noticeable near the center of the disk. This supports the use of decoupled models for injection molding in thin cavities. 相似文献
140.
MD Johnston BV Oliver DW Droemer B Frogget MD Crain Y Maron 《The Review of scientific instruments》2012,83(8):083108
This paper describes a convenient and accurate method to calibrate fast (<1 ns resolution) streaked, fiber optic light collection, spectroscopy systems. Such systems are inherently difficult to calibrate due to the lack of sufficiently intense, calibrated light sources. Such a system is used to collect spectral data on plasmas generated in electron beam diodes fielded on the RITS-6 accelerator (8-12MV, 140-200kA) at Sandia National Laboratories. On RITS, plasma light is collected through a small diameter (200 μm) optical fiber and recorded on a fast streak camera at the output of a 1 meter Czerny-Turner monochromator. For this paper, a 300 W xenon short arc lamp (Oriel Model 6258) was used as the calibration source. Since the radiance of the xenon arc varies from cathode to anode, just the area around the tip of the cathode ("hotspot") was imaged onto the fiber, to produce the highest intensity output. To compensate for chromatic aberrations, the signal was optimized at each wavelength measured. Output power was measured using 10 nm bandpass interference filters and a calibrated photodetector. These measurements give power at discrete wavelengths across the spectrum, and when linearly interpolated, provide a calibration curve for the lamp. The shape of the spectrum is determined by the collective response of the optics, monochromator, and streak tube across the spectral region of interest. The ratio of the spectral curve to the measured bandpass filter curve at each wavelength produces a correction factor (Q) curve. This curve is then applied to the experimental data and the resultant spectra are given in absolute intensity units (photons∕sec∕cm(2)∕steradian∕nm). Error analysis shows this method to be accurate to within +∕- 20%, which represents a high level of accuracy for this type of measurement. 相似文献