A new electrospinning apparatus was developed to generate nanofibrous materials with improved organizational control.
The system functions by oscillating the deposition signal ODS of multiple collectors, allowing significantly improved nanofiber control by manipulating the electric field which drives the electrospinning process. Other electrospinning techniques designed to impart deposited fiber organizational control, such as rotating mandrels or parallel collector systems, do not generate seamless constructs with high quality alignment in sizes large enough for medical devices.
Additionally, the mechanism of our technique allows for scale-up beyond these dimensions. The ODS collection system produced The ODS technique could be applied to any electrospinnable polymer to overcome the more limited uniformity and induced mechanical strain of rotating mandrel techniques, and greatly surpasses the limited length of standard parallel collector techniques.
Electrospinning is a cost-effective nanofiber production technique gaining popularity due to its ease of use, broad polymer compatibility, and receptivity to system modifications. The basic electrospinning technique involves the generation of a strong electric field between a polymer solution passing through a metallic capillary tip or spin-neret set to high voltage and a grounded collection plate [ 1 — 3 ].
When the voltage reaches a critical value, solution charge overcomes the surface tension of the deformed drop of the polymer solution, producing a jet at the spinneret tip that travels towards the collector plate [ 3 — 5 ].
Along its path, the jet undergoes a series of electrically induced bending instabilities as solution fractions of varying charge repel and attract each other. This results in extensive stretching of the jet through a violent whipping mechanism known as the instability region [ 256 ], which transforms the dissolved molecules within the jet into thousands of stiffened nano-scale fibers.
Residual solvent evaporates from the surface of the fibers as they descend towards the collector, reducing the fiber diameter and compacting the fibers. A dense network of dry nanofibers is ultimately deposited on the collector.
Fiber deposition patterns at the system collector are determined by the shape, size, and position of the system collector [ 5 — 7 ], which controls the size and curvature or diameter of the instability region. Through appropriate design of the collection system, electrospinning configu-rations can be modified to tune the mechanical properties, porosity and degradability by tissue-resident enzymes of the electrospun fibers [ 7 — 13 ].
Specific properties can be selected to optimize deposited fiber networks for particular applications including planar meshes, tubes and three-dimensional scaffolds [ 13 — 18 ]. Electrospun materials have been used as wound dressings, tissue scaffolds, nerve guides, vascular grafts, drug delivery vehicles and affinity membranes [ 11131519 — 23 ]. Each of these applications has benefited from the development and implementation of novel hardware modifications imparting new capabilities not previously available on common commercial electrospinning systems.
Consistent control of fiber organization throughout the mesh is important not only for the reliable production of desired mechanical properties, but also because when cells are seeded onto electrospun meshes, the nanofibrous topography has been shown to have a strong influence on cellular organization and integration, which is critical to proper scaffold function [ 24 — 26 ]. In addition, it may be desirable that as the material degrades or cells infiltrate deeper into the scaffold, a consistent nanofiber topography be presented, to maintain cell viability.
Accordingly, methods for controlling the alignment of deposited nanofibers are crucial for many clinically important applications of electrospun biomaterials. Unfortunately, current methods for controlling alignment have significant disadvantages. Fiber alignment can be improved simply through the use of multiple collectors in parallel, but the resulting product size is limited [ 2728 ].
At present, the most popular collection method for directing fiber alignment is the rotating mandrel or wheel, a process in which fibers deposit onto the surface of a rapidly rotating mandrel collector, aligning in the direction of mandrel rotation [ 29 — 31 ]. However, although mandrel systems are capable of producing much larger aligned fiber samples than parallel collector techniques, the alignment quality is inferior.
Mechanical forces exerted by the rotating mandrel on the fibers as they deposit introduce inconsistent areas of strain to each fiber, degrading fiber diameters and causing fiber breaks, fatigue, and plastic deformation.
Parallel collector and rotating mandrel techniques have several additional drawbacks that are common to both. Neither is capable of producing a controlled gradient in random-to-aligned fiber orientations blended into the direction of fiber alignment. Such a capability could address the difficulty of merging two interconnected tissue types, such as in muscle—tendon or ligament—bone junctions. In addition, current methods are incapable of electrospinning seamless, true axially aligned nanofibrous tubes, which are important for providing topological cues capable of guiding endothelial cell morphology and neural outgrowth in appropriate orientations [ 13253032 — 35 ].Testing VIRAL TIKTOK MINECRAFT HACKS AGAIN! **THEY WORKED**
As a result, there remains a need for hardware configurations that can produce high purity, axially aligned meshes, seamless tubes and scaffolds with fiber orientation and density gradients in the direction of alignment.E-mail: huanpangchem hotmail.
As a result of novel layered structures, there are many nanolayered channels for the diffusion of ions and electrolytes. Metal phosphates, especially for layered metal phosphates and phosphonates have been studied in the years — Typical low-magnification SEM image in Fig. The microrod has not a uniform diameter, while it has a small end and a large end shown in Fig. The layered nanoscale properties were further revealed in Fig. It confirms the nanolayered structures and the size of a layer is about The measured distances of the neighboring lattice fringes in Fig.
The product was synthesized under different hydrothermal conditions seen in ESI Fig. From ESI Fig. After hydrothermal condition for 16 hours, many microrods were obtained, and some microbundles assembled short nanorods were observed among these microrods in ESI Fig. The pore-size distribution in inset of Fig. The average pore diameter of the sample is 1. What is more, thousands of nanochannels might largely improve diffusion of ions and electrolytes, and the microbundle might offer a stable skeleton for ions intercalation—extraction.
As seen in the Fig. Chronopotentiometry CP curves at different current densities are shown in Fig. The relationship between the specific capacitances calculated by CP curves and current densities are given in Fig. It is very important for electrode materials to have good specific capacitance retention. Supercapacitors should work steadily and safely, which requires the specific capacitance of electrode materials to change as little as possible.
It shows its excellent specific capacitance retention under at 1. An equivalent circuit used to fit the impedance curve is given in inset of Fig. The EIS data can be fitted by a bulk solution resistance R sa charge-transfer R ct and a pseudocapacitive element C p from redox process of electrode materials, and a CPE to account for the double-layer capacitance. In addition, the charge-transfer resistance R ctalso called Faraday resistance, is a limiting factor for the specific power of the supercapacitor.
This layered structure surface-interface character might also decrease the polarization of the electrode, and thus increase the capacity. It is seen that the nanolayer structure is stable after cycle in ESI Fig. The phenomenon is enhanced by further prolonging the charging—discharging to cycle. It is found that the intensity of crystal plane has become weak with cycle numbers increasing. More importantly, the peak of samples after cycles has shifted a little into the small angle of diffraction, which might be caused by ions intercalation into nanolayer structures in Fig.
These characteristics are similar to those of CoOOH in a report. The higher equivalent series resistance ESR value, the equivalent circuit is shown in inset of Fig.
Moreover, these phase angles have changed a little except that of the electrode after cycle, which means ions or electrolyte transfer to occur quickly even after long charge—discharge cycling. While a three-electrode cell is valuable for determining electrochemical-specific material characteristics, a two-electrode test cell mimics the physical configuration, internal voltages and charge transfer that occurs in a packaged ultracapacitor and thus providing the best indication of an electrode material's performance.
Typical charge—discharge curves of cells from 0 to 1. On the curve in 3. Then, the cell voltage is gradually increased, and a quasi-linear voltage-time response is visible between 0 and 1. The specific energy of cell in 3. However, the specific energy of cell in 3. All electrochemical performances were carried out in a conventional three-electrode system equipped with platinum electrode and a saturated calomel electrode SCE as counter and reference electrodes, respectively.
Before electrochemical measurement, we have purged out O 2 from the solution by the inert gas — Ar.Author: L. Siebenmann Journal: Trans. References [Enhancements On Off] What's this? Cambridge Philos. MR  W. BrowderJ. Levineand G. LivesayFinding a boundary for an open manifoldAmer. ConnellD.
Montgomeryand C. WilderUniform local connectedness and contractibilityAmer. EpsteinThe degree of a mapProc. London Math. Fox and Emil ArtinSome wild cells and spheres in three-dimensional spaceAnn. Haefliger and C. WallPiecewise linear bundles in the stable rangeTopology 4— Hempel and D. McMillan Jr. HirschOn combinatorial submanifolds of differentiable manifoldsComment. HirschSmooth regular neighborhoodsAnn. HirschObstruction theories for smoothing manifolds and mapsBull.
HirschOn tangential equivalence of manifoldsAnn. HirschOn normal microbundlesTopology 5— Hudson and E. ZeemanOn combinatorial isotopyInst. MR  J. ZeemanOn regular neighbourhoodsProc. IAnn. Stable applicationsAnn. Studies, No.Zelda's Season Pass, called the Expansion Pass, was revealed yesterday but one overlooked sentence in the announcement makes the deal even worse The amount of negativity this is getting has gotten out of hand; I don't recall people complaining nearly this much when TLOU did something similar.
It's sony that why. And I think its just something the haters needed to use to start hating again because they are running out of options. Brad While Sony gives freedom more than any other publisher and actually are willing to take risk they do in ND and any IP nd work on. It seems Nintendo is reluctant to assimilate when it comes to positive things such as powerful hardware, and securing legitimate third party support not old ports and sports titles, I mean the majority of AAA releases ; but they have no problem assimilating when it comes to negative things such as online subscriptions and season passes.
Nintendo wants to separate themselves from the competition, they don't want to be like Sony or Microsoft, they want to do their own thing Get raped and your throat slashed, Otaku. You are a worthless nigger stain and Christopher is protecting you so he can groom your underage ass! Nopeit's Naughty Dog I watch an interview with them an they stated that they do what they want with games Sony has no control over them. Funny thing about that. It isnt a zombie game. Its a game about 2 characters surviving no matter what.
And the setting was the last thing they decided. Thats the difference between games like ohh last of us and dead rising. Ones a generic zombie game. The other is a story of two people.
WTH does this have to do with Sony? I do agree tho that all these articles are getting out of hand, not getting it at all, but then again, people just love to hate on stuff these days Although i am not sure if TLOU should be mentioned in this article. But i do think that the hate for this dlc is unwarranted.
Oh please if Nintendo shit on their hand and clapped right in your face you'd probably find a way to defend them Comparing it to the TLOU makes no sense. Lets not forget they never added a hard more within the Season Pass and made it so you had to buy the full thing if you wanted it. Stupid comparison. The hard mode grounded mode was in the season pass for the Last of Us. But hey let's forget that the last of us had those stupid micro dlc bundles of what you say?
Oh yeah boosts and outfits Left Behind was only released as a standalone more than a year after it was released as DLC.Extending combinatorial piecewise linear structures on stratified spaces. Authors: Douglas R. Abstract: Let X be a stratified space and suppose that both the complement of the n -skeleton and the n -stratum have been endowed with combinatorial piecewise linear PL structures.
The second main theorem describes a method for computing the homotopy groups arising in the obstruction theory problem via spectral sequence methods. In some cases, the spectral sequences involved are fairly small and the first few differentials are described.
This paper is an outgrowth of earlier work by the authors on this problem. References [Enhancements On Off] What's this? Anderson and W. Benjamin, Inc. MR  D. CohenA general theory of relative regular neighborhoodsTrans. Edwards and Robion C. KirbyDeformations of spaces of imbeddingsAnn. Farrell and W.
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Lashof and M. RothenbergTriangulation of manifolds. I, IIBull. MR  John MilnorTwo complexes which are homeomorphic but combinatorially distinctAnn.This is a preview of subscription content, log in to check access. Rent this article via DeepDyve.
Abraham, R. New York: Benjamin Google Scholar. Arnold, V. Camacho, C. Cossart, V. Notes Math. Douady, A. Edwards, R. After F.
Zelda's Season Pass is Worse Than You Think
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Rent this article via DeepDyve. Barratt, M. Gugenheimand J. Moore : On semi-simpllicial fibrebundles. Google Scholar. Browder, Wm.
The index of a holomorphic flow with an isolated singularity
Princeton mimeographed. Hirsch, M. Cambridge University of California, Berkeley mimeographed. Hudson, J. Cambridge University mimeographed. Zeeman : On combinatorial isotopy. Hautes Etudes Sci. London Math. Kan, Daniel M.
Milnor, J. Princeton University, mimeographed. Moore, J. Kuiper, N. Lashof : Microbundles and bundles I. Download references. Mathematisch Instituut der Universiteit Amsterdam, Amsterdam. Department of Mathematics University of Chicago, Chicago. Reprints and Permissions. Microbundles and bundles. Invent Math 1, — Download citation. Received : 06 April Issue Date : September Search SpringerLink Search. Immediate online access to all issues from