scholarly journals Nanoparticle-doped electrospun fiber random lasers with spatially extended light modes

2017 ◽  
Vol 25 (20) ◽  
pp. 24604 ◽  
Author(s):  
Vincenzo Resta ◽  
Andrea Camposeo ◽  
Martina Montinaro ◽  
Maria Moffa ◽  
Karolis Kazlauskas ◽  
...  
Keyword(s):  
Electrospun Fiber ◽  
Random Lasers ◽  
Spatially Extended

scholarly journals A random laser based on electrospun polymeric composite nanofibers with dual-size distribution

2019 ◽  
Vol 1 (2) ◽  
pp. 728-734 ◽  
Author(s):  
Mário César Albuquerque de Oliveira ◽  
Leonardo de Souza Menezes ◽  
Pablo I. R. Pincheira ◽  
Carlos Rojas-Ulloa ◽  
Nikifor Rakov Gomez ◽  
...  
Keyword(s):  
Composite Nanofibers ◽  
Electrospun Fiber ◽  
Polymeric Composite ◽  
Essential Elements ◽  
Random Laser ◽  
Flexible Systems ◽  
Broad Distribution ◽  
Environment Friendly ◽  
Random Lasers ◽  
Lasing Mechanism

Electrospun fiber-based random lasers are environment-friendly flexible systems in which waveguiding/scattering processes provided by their structure with a broad distribution of diameters are essential elements to generate a suitable lasing mechanism.

Magnetic Fields Enable Precise Spatial Control of Electrospun Fiber Alignment for Fabricating Complex Gradient Materials

2020 ◽  
Author(s):  
R. Kevin Tindell ◽  
Lincoln Busselle ◽  
Julianne Holloway
Keyword(s):  
Magnetic Field ◽  
Electrospun Fiber ◽  
Cell Phenotype ◽  
Fibrous Materials ◽  
Fibrous Scaffold ◽  
Spatial Control ◽  
Fiber Alignment ◽  
Aligned Fibers ◽  
The Magnetic Field ◽  
Magnetically Assisted

<div>Musculoskeletal interfacial tissues consist of complex gradients in structure, cell phenotype, and biochemical signaling that are important for function. Designing tissue engineering strategies to mimic these types of gradients is an ongoing challenge. In particular, new fabrication techniques that enable precise spatial control over fiber alignment are needed to better mimic the structural gradients present in interfacial tissues, such as the tendon-bone interface. Here, we report a modular approach to spatially controlling fiber alignment using magnetically-assisted electrospinning. Electrospun fibers were highly aligned in the presence of a magnetic field and smoothly transitioned to randomly aligned fibers away from the magnetic field. Importantly, magnetically-assisted electrospinning allows for spatial control over fiber alignment at sub-millimeter resolution along the length of the fibrous scaffold similar to the native structural gradient present in many interfacial tissues. The versatility of this approach was further demonstrated using multiple electrospinning polymers and different magnet configurations to fabricate complex fiber alignment gradients. As expected, cells seeded onto gradient fibrous scaffolds were elongated and aligned on the aligned fibers and did not show a preferential alignment on the randomly aligned fibers. Overall, this fabrication approach represents an important step forward in creating gradient fibrous materials and are promising as tissue-engineered scaffolds for regenerating functional musculoskeletal interfacial tissues. <br></div>

Magnetic Fields Enable Precise Spatial Control of Electrospun Fiber Alignment for Fabricating Complex Gradient Materials

2020 ◽  
Author(s):  
R. Kevin Tindell ◽  
Lincoln Busselle ◽  
Julianne Holloway
Keyword(s):  
Magnetic Field ◽  
Electrospun Fiber ◽  
Cell Phenotype ◽  
Fibrous Materials ◽  
Fibrous Scaffold ◽  
Spatial Control ◽  
Fiber Alignment ◽  
Aligned Fibers ◽  
The Magnetic Field ◽  
Magnetically Assisted

<div>Musculoskeletal interfacial tissues consist of complex gradients in structure, cell phenotype, and biochemical signaling that are important for function. Designing tissue engineering strategies to mimic these types of gradients is an ongoing challenge. In particular, new fabrication techniques that enable precise spatial control over fiber alignment are needed to better mimic the structural gradients present in interfacial tissues, such as the tendon-bone interface. Here, we report a modular approach to spatially controlling fiber alignment using magnetically-assisted electrospinning. Electrospun fibers were highly aligned in the presence of a magnetic field and smoothly transitioned to randomly aligned fibers away from the magnetic field. Importantly, magnetically-assisted electrospinning allows for spatial control over fiber alignment at sub-millimeter resolution along the length of the fibrous scaffold similar to the native structural gradient present in many interfacial tissues. The versatility of this approach was further demonstrated using multiple electrospinning polymers and different magnet configurations to fabricate complex fiber alignment gradients. As expected, cells seeded onto gradient fibrous scaffolds were elongated and aligned on the aligned fibers and did not show a preferential alignment on the randomly aligned fibers. Overall, this fabrication approach represents an important step forward in creating gradient fibrous materials and are promising as tissue-engineered scaffolds for regenerating functional musculoskeletal interfacial tissues. <br></div>

Walter Benjamin's media theory and the tradition of the media diaphana

2016 ◽  
Vol 7 (1) ◽  
pp. 9-26
Author(s):  
Antonio Somaini
Keyword(s):  
Sensory Experience ◽  
Media Theory ◽  
Depth Analysis ◽  
Spatially Extended ◽  
The Media ◽  
Aristotelian Tradition

"The article presents an in-depth analysis of Benjamin’s use of the German term Medium, in order to show how his entire media theory may be interpreted as centered on the interaction between the historically changing realm of the technical and material Apparate, and what he calls in the artwork essay the »Medium of perception«: the spatially extended environment, the atmosphere, the milieu, the Umwelt in which sensory experience occurs. This notion of »Medium of perception« is then located within the long, post-Aristotelian tradition of the media diaphana, whose traces can be found in the 1920s and 1930s in the writings of authors such as Béla Balázs, Fritz Heider, and László Moholy-Nagy. </br></br>Der Artikel präsentiert eine eingehende Analyse von Benjamins Gebrauch des deutschen Begriffs »Medium«, um zu zeigen, dass seine gesamte Medientheorie fokussiert ist auf die Interaktion zwischen dem historisch veränderlichen Bereich der technischen und materiellen Apparate einerseits und dem, was er in dem Kunstwerkaufsatz das »Medium der Wahrnehmung« nennt: die räumlich ausgedehnte Umgebung, die Atmosphäre, das Milieu, die Umwelt, in der sinnliche Wahrnehmung erfolgt. Dieser Begriff des »Mediums der Wahrnehmung« wird dann innerhalb der langen, nacharistotelischen Tradition der media diaphana verortet, deren Spuren in den 1920er und 1930er Jahren in den Schriften von Autoren wie Béla Balázs, Fritz Heider und László Moholy-Nagy zu finden sind."

scholarly journals Gaia-assisted discovery of a detached low-ionisation BAL quasar with very large ejection velocities

2020 ◽  
Vol 634 ◽  
pp. A111 ◽  
Author(s):  
J. P. U. Fynbo ◽  
P. Møller ◽  
K. E. Heintz ◽  
J. N. Burchett ◽  
L. Christensen ◽  
...  
Keyword(s):  
Emission Line ◽  
Absorption Line ◽  
Emission Lines ◽  
Broad Absorption ◽  
Broad Absorption Line ◽  
Red Edge ◽  
First Case ◽  
Bl Lac ◽  
Spatially Extended ◽  
Extended Emission

We report on the discovery of a peculiar broad absorption line (BAL) quasar identified in our Gaia-assisted survey of red quasars. The systemic redshift of this quasar was difficult to establish because of the absence of conspicuous emission lines. Based on deep and broad BAL troughs of at least Si IV, C IV, and Al III, a redshift of z = 2.41 was established under the assumption that the systemic redshift can be inferred from the red edge of the BAL troughs. However, we observe a weak and spatially extended emission line at 4450 Å that is most likely due to Lyman-α emission, which implies a systemic redshift of z = 2.66 if correctly identified. There is also evidence for the onset of Lyman-α forest absorption bluewards of 4450 Å and evidence for Hα emission in the K band consistent with a systemic redshift of z = 2.66. If this redshift is correct, the quasar is an extreme example of a detached low-ionisation BAL quasar. The BALs must originate from material moving with very large velocities ranging from 22 000 km s−1 to 40 000 km s−1. To our knowledge, this is the first case of a systemic-redshift measurement based on extended Lyman-α emission for a BAL quasar. This method could also be useful in cases of sufficiently distant BL Lac quasars without systemic-redshift information.

scholarly journals Polylactic acid-based electrospun fiber and hyaluronic acid-valsartan hydrogel scaffold for chronic wound healing

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Margaret O. Ilomuanya ◽  
Prosper S. Okafor ◽  
Joyce N. Amajuoyi ◽  
John C. Onyejekwe ◽  
Omotunde O. Okubanjo ◽  
...  
Keyword(s):  
Wound Healing ◽  
Hyaluronic Acid ◽  
Polylactic Acid ◽  
Chronic Wound ◽  
Electrospun Fiber ◽  
Hydrogel Scaffold

scholarly journals Unconventional singularities and energy balance in frictional rupture

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Efim A. Brener ◽  
Eran Bouchbinder
Keyword(s):  
Energy Balance ◽  
Square Root ◽  
Earthquake Physics ◽  
Macroscopic Theory ◽  
Scale Separation ◽  
Rate Dependent ◽  
Theoretical Predictions ◽  
Spatially Extended ◽  
Singularity Order ◽  
Square Root Singularity

AbstractA widespread framework for understanding frictional rupture, such as earthquakes along geological faults, invokes an analogy to ordinary cracks. A distinct feature of ordinary cracks is that their near edge fields are characterized by a square root singularity, which is intimately related to the existence of strict dissipation-related lengthscale separation and edge-localized energy balance. Yet, the interrelations between the singularity order, lengthscale separation and edge-localized energy balance in frictional rupture are not fully understood, even in physical situations in which the conventional square root singularity remains approximately valid. Here we develop a macroscopic theory that shows that the generic rate-dependent nature of friction leads to deviations from the conventional singularity, and that even if this deviation is small, significant non-edge-localized rupture-related dissipation emerges. The physical origin of the latter, which is predicted to vanish identically in the crack analogy, is the breakdown of scale separation that leads an accumulated spatially-extended dissipation, involving macroscopic scales. The non-edge-localized rupture-related dissipation is also predicted to be position dependent. The theoretical predictions are quantitatively supported by available numerical results, and their possible implications for earthquake physics are discussed.

Sign in / Sign up

Export Citation Format

Share Document