This work shows a method to recover the shape of the precision glass molding surface via null-screen test. For the validation of the proposed method, we analyzed the ACL25416U condenser lens ...fabricated by Thorlabs. The results show that the conic constant, the radius of curvature and the aspheric deformation coefficients can be retrieved with good accuracy.
Abstract
This article examines a kinematic model of a group pursuing several targets by the method of parallel approach. The model is based on the fact that pursuers try to adhere to pre-designed ...trajectories. The pursuers’ trajectories have curvature constraints. The initial directions of the pursuers’ velocities are arbitrary, which changes the well-known method of parallel approach. In our model, targets are chased by the pursuers simultaneously. This is due to the change in the lengths of the predicted trajectories in such a way as to synchronize the time to reach the target. The change in the lengths of the predicted trajectories occurs due to an increase in the radius of curvature in the initial segment of the trajectory.
Holographic conformal field theories (CFTs) are usually studied in a limit where the gravity description is weakly coupled. By contrast, lattice quantum field theory can be used as a tool for doing ...computations in a wider class of holographic CFTs where nongravitational interactions in AdS become strong, and gravity is decoupled. We take preliminary steps for studying such theories on the lattice by constructing the discretized theory of a scalar field in AdS2 and investigating its approach to the continuum limit in the free and perturbative regimes. Our main focus is on finite sublattices of maximally symmetric tilings of hyperbolic space. Up to boundary effects, these tilings preserve the triangle group as a large discrete subgroup of AdS2, but have a minimum lattice spacing that is comparable to the radius of curvature of the underlying spacetime. We quantify the effects of the lattice spacing as well as the boundary effects, and find that they can be accurately modeled by modifications within the framework of the continuum limit description. We also show how to do refinements of the lattice that shrink the lattice spacing at the cost of breaking the triangle group symmetry of the maximally symmetric tilings.
Purpose
To evaluate changes in corrected distance visual acuity (CDVA), ratio of anterior and posterior corneal radii over the thinnest region of the cornea (ARC/PRC), and astigmatism after ...cross-linking (CXL) in keratoconus.
Methods
Subjective refraction and ARC/PRC (using Pentacam™) were monitored over 1 year in (I) keratoconus treated with routine CXL (
n
= 53), (II) relatively stable keratoconus (
n
= 23), and (III) age/gender matched controls (
n
= 24).
Results
CDVA (median, mode, interquartile range) improved significantly in group I, compared with groups II and III (
p
< 0.05), from 0.45 (0.60, 0.20–0.63) to 0.80 (0.95, 0.60–0.95); change in CDVA was associated with preop CDVA (
p
< 0.01 at all times postop). ARC/PRC (mean ± sd, 95% CI) changed from 1.362 (± 0.048, 1.347–1.377) to 1.425 (± 0.073, 1.401–1.449). CDVA and ARC/PRC remained stable in II and III. Significant relationships were revealed between logCDVA and ARC/PRC in I and II (at 12 months, I
r
s
= − 0.464, II
r
s
− 0.449) and logCDVA at postop(y), log CDVA at preop(x
1
), and ARC/PRC at preop(x
2
) in I (at 12 months,
y
= 0.356
x
1
− 1.312
x
2
+ 1.806,
r
2
1
= 0.494,
r
2
2
= 0.203). Astigmatic power (mean ± sd, 95% CI) improved from − 3.10DC (± 1.52, − 3.55 to − 2.66) to − 2.53DC (± 1.24, − 2.90 to − 2.17) in I, and worsened from − 1.27DC (± 1.32, − 1.81 to − 0.73) to − 1.61DC (± 1.28, − 2.13 to − 1.09) in II. Vector analysis revealed in group I (a) the power of the surgically induced astigmatism (SIA) was linked to astigmatic power at preop and (b) the difference between the axis of astigmatism at preop(ø) and the axis of the SIA was linked to ø.
Conclusion
CXL improved CDVA, increased the ARC/PRC ratio, and modified the association between CDVA and ARC/PRC. The change in CDVA was linked to preop CDVA and ARC/PRC values. The association between SIA and preop astigmatism implies there is not a simple cause and effect relationship with CXL.
Formation of thick, high energy density, flexible solid supercapacitors is challenging because of difficulties infilling gel electrolytes into porous electrodes. Incomplete infilling results in a low ...capacitance and poor mechanical properties. Here we report a bottom-up infilling method to overcome these challenges. Electrodes up to 500 μm thick, formed from multi-walled carbon nanotubes and a composite of poly(3,4-ethylenedioxythiophene), polystyrene sulfonate and multi-walled carbon nanotubes are successfully infilled with a polyvinyl alcohol/phosphoric acid gel electrolyte. The exceptional mechanical properties of the multi-walled carbon nanotube-based electrode enable it to be rolled into a radius of curvature as small as 0.5 mm without cracking and retain 95% of its initial capacitance after 5000 bending cycles. The areal capacitance of our 500 μm thick poly(3,4-ethylenedioxythiophene), polystyrene sulfonate, multi-walled carbon nanotube-based flexible solid supercapacitor is 2662 mF cm
at 2 mV s
, at least five times greater than current flexible supercapacitors.
Lightweight and flexible energy storage devices are urgently needed to persistently power wearable devices, and lithium-sulfur batteries are promising technologies due to their low mass densities and ...high theoretical capacities. Here we report a flexible and high-energy lithium-sulfur full battery device with only 100% oversized lithium, enabled by rationally designed copper-coated and nickel-coated carbon fabrics as excellent hosts for lithium and sulfur, respectively. These metallic carbon fabrics endow mechanical flexibility, reduce local current density of the electrodes, and, more importantly, significantly stabilize the electrode materials to reach remarkable Coulombic efficiency of >99.89% for a lithium anode and >99.82% for a sulfur cathode over 400 half-cell charge-discharge cycles. Consequently, the assembled lithium-sulfur full battery provides high areal capacity (3 mA h cm
), high cell energy density (288 W h kg
and 360 W h L
), excellent cycling stability (260 cycles), and remarkable bending stability at a small radius of curvature (<1 mm).
Abstract In order to further improve the flight stability of explosively formed projectile, the formation method of tail EFP was studied based on the polygonal liner. Under the hexagonal charge ...structure, the tail fins EFP can be formed when the structural parameters are matched. Through the numerical simulation of LS-DYNA, the influence of the structural parameters of the liner (curvature radius, linear thickness), charge height and shell thickness on the velocity, length-diameter ratio, compactness and wing-diameter ratio of the tail fins EFP was analyzed. In order to make the tail fins EFP performance better, the optimal range of radius of curvature R of hexagon liner is 0.75D ~ 0.85D, liner thickness t is 0.05D ~ 0.06D, charge height L is 0.8D ~ 1.0D, and the optimal range of shell thickness h is 0.06D ~ 0.1D.
Abstract
Microcatheters have enabled diverse minimally invasive endovascular operations and notable health benefits compared with open surgeries. However, with tortuous routes far from the arterial ...puncture site, the distal vascular regions remain challenging for safe catheter access. Therefore, we propose a wireless stent-shaped magnetic soft robot to be deployed, actively navigated, used for medical functions, and retrieved in the example M4 segment of the middle cerebral artery. We investigate shape-adaptively controlled locomotion in phantoms emulating the physiological conditions here, where the lumen diameter shrinks from 1.5 mm to 1 mm, the radius of curvature of the tortuous lumen gets as small as 3 mm, the lumen bifurcation angle goes up to 120
°
, and the pulsatile flow speed reaches up to 26 cm/s. The robot can also withstand the flow when the magnetic actuation is turned off. These locomotion capabilities are confirmed in porcine arteries ex vivo. Furthermore, variants of the robot could release the tissue plasminogen activator on-demand locally for thrombolysis and function as flow diverters, initiating promising therapies towards acute ischemic stroke, aneurysm, arteriovenous malformation, dural arteriovenous fistulas, and brain tumors. These functions should facilitate the robot’s usage in new distal endovascular operations.
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