Window screen inspired fibrous materials with anisotropic thickness gradients for improving light transmittance

Nanoscale ◽  
2019 ◽  
Vol 11 (28) ◽  
pp. 13521-13531 ◽  
Author(s):  
Nan Pan ◽  
Juanrong Qin ◽  
Pingping Feng ◽  
Botao Song
Keyword(s):  
Light Transmittance ◽  
Fibrous Materials ◽  
Ultrafine Fibers ◽  
Window Screen

Ultrafine fibers were assembled into an anisotropic architecture for improving light transmittance.

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>

RHEOLOGICAL PROPERTIES OF CERAMIC MASSES: IMPROVEMENT BY COMPLEX MATERIAL ACTIVATION

2019 ◽  
Vol 16 (3) ◽  
pp. 334-351
Author(s):  
A. S. Mavlyanov ◽  
E. K. Sardarbekova
Keyword(s):  
Rheological Properties ◽  
Raw Materials ◽  
Sensitivity Coefficient ◽  
Raw Material ◽  
Clay Material ◽  
Fibrous Materials ◽  
Chemical Production ◽  
Production Wastes ◽  
Pass Through ◽  
The Masses

Introduction. The objective of the research is to study the effect of the complex activation of the alumina raw material on the rheological properties of the ceramic mass. In addition, the authors investigate solutions for the application of optimal coagulation structures based on loams and ash together with plastic certificates.Materials and methods. The authors used the local forest like reserves of clay loams at the BashKarasu, ash fields of the Bishkek Central Heating Centre (BTEC) and plasticizer (sodium naphthenate obtained from alkaline chemical production wastes) as fibrous materials. Moreover, the authors defined technological properties of raw materials within standard laboratory methodology in accordance with current GOSTs.Results. The researchers tested plastic durability on variously prepared masses for the choice of optimal structures. The paper demonstrated the plastic durability of complexly activated compounds comparing with non-activated and mechanically activated compounds. The sensitivity coefficient increased the amount of clay loams by mechanically and complexly activated, which predetermined the possibility of intensifying the process of drying samples based on complexly activated masses.Discussion and conclusions. However, mechanical activation of clay material reduces the period of relaxation and increases the elasticity coefficient of ceramic masses by 1.8–3.4 times, meanwhile decreases elasticity, viscosity and the conventional power during molding, which generally worsens the molding properties of the masses. Сomplex activation of ash-clay material decreases the period of relaxation and provides an increase in elasticity, plasticity of ceramic masses by 46–47%, reduction in viscosity by 1.5–2 times, conventional power on molding by 37–122% in comparison with MA clay loams. Ceramic masses based on spacecraft alumina raw materials belong to the SMT with improved rheological properties; products based on them pass through the mouthpiece for 5–7 seconds.

Flocculation of Waste Waters from Petroleum Refineries

1974 ◽  
Vol 9 (1) ◽  
pp. 302-314
Author(s):  
André Hade ◽  
Acher Elcabetz
Keyword(s):  
Electrophoretic Mobility ◽  
Light Transmittance ◽  
Waste Waters ◽  
Critical Coagulation Concentration ◽  
Mobility Rate ◽  
Anionic Polymers ◽  
Petroleum Refineries ◽  
Binary Suspension

Abstract Waste waters from petroleum refineries can be considered as a ternary-like system, the components of which have been characterized. They are: the alkaline liquor, the hydrocarbon rich oil in suspension and the silica rich solid also in suspension. The parameters controlling the destabilization and the flocculation of these suspensions have been studied by light transmittance and electrophoretic mobility. Rate of flocculation, critical coagulation concentration (CCC) , critical restabilization concentration and optimum flocculation conditions have been determined for different combinations of added polyelectrolytes and/or simple electrolytes. Among eleven different polyelectrolytes, four of the cationic type were selected for their property to flocculate the suspension. It has been shown that an excess of polyelectrolyte brings about the restabilization of the particules. No flocculation has been observed for any of the anionic polymers tested. Simple electrolytes are found to obey the Schulze-Hardy rule in their flocculation capacity. Various combinations of a polyelectrolyte with a simple salt lead to a lower CCC together with a broader concentration range between destabilization and restabilization. It is concluded that this binary suspension behaved essentially like a classical lyophobic sol.

Asbestos and Other Fibrous Materials

1989 ◽  
Author(s):  
H. Catherine W. Skinner ◽  
Malcolm Ross ◽  
Clifford Frondel
Keyword(s):  
Environmental Health ◽  
Inorganic Materials ◽  
Health Hazards ◽  
General Description ◽  
Fibrous Materials ◽  
Legal Professionals ◽  
Naturally Occurring

This comprehensive sourcebook describes the chemical, physical, and mineralogical aspects of fibrous inorganic materials, both synthetic and naturally occurring. A general description of the fibrous state, the range of compounds that can adopt this form, and an overview of the characteristics unique to such materials form the backbone of the book . The authors also assess the application and use of asbestos and other fibrous materials in industry and evaluate their potential as health hazards. The information gathered here will be highly useful to medical investigators and legal professionals involved in environmental health.

Imaging NMDA- and kainate-induced intrinsic optical signals from the hippocampal slice

1996 ◽  
Vol 76 (4) ◽  
pp. 2707-2717 ◽  
Author(s):  
R. D. Andrew ◽  
J. R. Adams ◽  
T. M. Polischuk
Keyword(s):  
Nmda Receptor ◽  
Receptor Antagonist ◽  
Ampa Receptors ◽  
Hippocampal Slice ◽  
Field Potential ◽  
Nmda Receptor Antagonist ◽  
Light Transmittance ◽  
Stratum Radiatum ◽  
Cell Swelling ◽  
Tissue Resistance

1. Brain ischemia causes excess release and accumulation of glutamate that binds to postsynaptic receptors. This opens ionotropic channels that mediate neuronal depolarization and ionic fluxes that can lead to neuronal death. 2. The CA1 pyramidal cell region of the hippocampus is particularly susceptible to this neurotoxic process. Brain cell swelling is considered an early excitotoxic event, but remains poorly under stood and documented. As cells swell, light transmittance (LT) increases through brain tissue, so we hypothesized that brief exposure to glutamate agonists would elicit cell swelling that could be imaged in real time in the hippocampal slice. 3. A 1-min bath application of 100 microM N-methyl-D-aspartate (NMDA) or 100 microM kainate at 22 degrees C greatly increased LT, particularly in the dendritic regions of CA1. The response peaked by 2-3 min and slowly reversed over the subsequent 20 min following exposure. Peak LT increases were > 50% in CA1 stratum radiatum and > 20% in both CA1 stratum oriens and the dendritic region of the dentate gyrus, all areas with a high concentration of NMDA and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptors. The CA3 stratum radiatum, which contains fewer of these receptors, showed a comparatively small LT increase. 4. The NMDA receptor antagonist 2-amino-5-phosphonovalerate (AP-5) [but not 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX)] blocked the CA1 response to NMDA, whereas the non-NMDA receptor antagonist CNQX (but not AP-5) blocked the response to kainate. The relative tissue resistance measured across CA1 stratum radiatum increased after NMDA or kainate exposure with a time course similar to the LT change described above. The increase in relative tissue resistance was blocked by kynurenate, a nonspecific glutamate antagonist. Increases in both LT and tissue resistance provide two independent lines of evidence that cell swelling rapidly developed in CA1 dendritic areas after activation of NMDA or AMPA receptors. 5. This swelling at 22 degrees C was accompanied by a temporary loss of the evoked CA1 field potential. However, at 37 degrees C the dendritic swelling rapidly progressed to an irreversible LT increase (swelling) of the CA1 cell bodies accompanied by a permanent loss of the evoked field. 6. We propose that dendritic swelling mediated by NMDA and AMPA receptors is an early excitotoxic event that can herald permanent damage to CA1 neurons, those cells most vulnerable to ischemic insult.

Sign in / Sign up

Export Citation Format

Share Document