- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Li Permeability Increase in Nano-Sized Amorphous Silicon Layers
摘要： Li permeation through nano-sized amorphous Si layers is investigated for temperatures up to 500°C (773 K) as a function of layer thickness between 12 and 95 nm. For the experiments the Si layers are embedded between 6Li and 7Li isotope enriched oxide based Li reservoirs and the thermally induced isotope exchange (through silicon layers and interfaces) is analyzed by Secondary Ion Mass Spectrometry in order to calculate Li permeabilities. The experiments reveal that the interface between silicon and the Li metal oxide does not hinder Li permeation and Li diffusion in silicon controls the overall process. The determined Li permeability increases drastically by orders of magnitude with decreasing silicon layer thickness, accompanied by a decrease in the activation enthalpy of Li permeation. These results can be explained by a gradual transition of trap-limited slow Li diffusion at high silicon thicknesses to interstitial fast Li diffusion at low Si thicknesses.
关键词： Li permeation,nano-sized layers,Li permeability,trap-limited diffusion,amorphous silicon,Secondary Ion Mass Spectrometry,isotope exchange,interstitial diffusion
更新于2025-09-23 15:21:21
-
Permittivity and Permeability Characterization of SiC and Ferro Metals for Structural Health Monitoring Utilization
摘要： The need for wireless sensing technology has rapidly increased recently, specifically the usage of electromagnetic waves which becoming more required as a source of information. Silicon carbide (SiC) Nano particles has been used in this study, the material under test (MUT) was exposed directly to a microwave field to examine the electromagnetic behavior. The permittivity and permeability were investigated with different filler materials to approach best and optimal electromagnetic absorbing characteristics to assist engineers to monitor structure-based composite for defects evaluation that may occur during operation conditions or through manufacturing process. XRD, FESEM and both complex permittivity and permeability were measured for the pure materials that candidate for this study. The results showed that all the selected nanostructure material exhibit a good purity with proper electromagnetic properties in the X- band, this can lead to absorbing and transmission properties that can be used in monitoring structures or manufactured part during fabrication process.
关键词： Silicon carbide,electromagnetic waves,structural health monitoring,permittivity,permeability
更新于2025-09-23 15:21:21
-
[IEEE 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Rome, Italy (2019.6.17-2019.6.20)] 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Differentiation of the Laser Pulse in a Waveguide with a Bragg Grating
摘要： A novel one-port probe technique, which combines the measurements of a rectangular waveguide and coaxial probe to nondestructively yield the permittivity and permeability of a PEC-backed material, is presented. A brief description of the derivation of the theoretical probe reflection coefficients, necessary for permittivity and permeability extraction via numerical inversion, is provided. Experimental characterization results of a PEC-backed magnetic material are presented to validate the proposed approach. Error analysis is also undertaken to quantify the new technique’s sensitivity to common experimental errors.
关键词： moment methods,microwave measurements,waveguides,Integral equations,permeability measurement,uncertainty,permittivity measurement,measurement uncertainty
更新于2025-09-23 15:21:01
-
Online optical inspection of air permeability of packaging materials during laser perforation
摘要： Laser perforations are formed in packaging to control the rate of gas exchange and maintain a balance between the respiration of the product and the permeation of the package. The air permeability of the packaging materials is typically measured using air-driven methods, but these do not allow for online measurement during the rapid production of perforations. The required permeability is generally obtained through trial and error. This paper describes the simulation of air-driven methods through computational fluid dynamics to study the effects of turbulence on the rate of air flow through perforations. A mathematical model is developed to quantify the influence of the micro-perforated size, the total area of exchange, and the thickness of the material on air permeability under certain temperature and pressure differences. The numerical results are in good agreement with the experimental results. An optical system based on the model is designed for the online inspection of packaging materials during the rapid production of laser perforations. Air permeability is precisely determined by analyzing continuous images of the perforations. Perforation characteristics such as shape, quantity, and density can also be measured to allow for feedback control of the perforation process according to the features of the packaged products. The validity and accuracy of the developed system are experimentally verified.
关键词： optical measurement,laser perforation,air permeability,CFD modeling
更新于2025-09-23 15:21:01
-
[IEEE 2019 IEEE Asia-Pacific Microwave Conference (APMC) - Singapore, Singapore (2019.12.10-2019.12.13)] 2019 IEEE Asia-Pacific Microwave Conference (APMC) - Supercoupling Effect in Substrate Integrated Waveguide Loaded with Mu-Near-Zero Material and its Potential Application
摘要： In this work, a supercoupling effect is corroborated in a substrate integrated waveguide (SIW) via a perfectly mismatched channel comprising of the mu-near-zero (MNZ) material. This phenomenon is actually the dual of the tunneling effect as observed due to the epsilon-near-zero (ENZ) channel. For observing the supercoupling, two SIWs having highly different cross-sections are coupled with the broader SIW loaded with the dispersive material providing MNZ at a certain frequency. At this frequency, the SIW yields a high transmission coefficient along with the constant magnetic field intensity throughout the channel. The channel, is then, ultimately exploited at the MNZ for testing the magnetic samples possessing varying permeabilities, hence, perceiving its potential application.
关键词： magnetic sample testing,substrate integrated waveguide,permeability,supercoupling,mu-near-zero
更新于2025-09-23 15:19:57
-
PET Imaging of the EPR Effect in Tumor Xenografts Using Small 15 nm Diameter Polyethylene Glycols Labeled with Zirconium-89
摘要： The goal was to develop and characterize a companion diagnostic for the releasable PEG40kDa~SN-38 oncology drug, PLX038, that would identify tumors susceptible to high accumulation of PLX038. PEG conjugates of the zirconium ligand desferroxamine B (DFB) of similar size and charge to PLX038 were prepared that contained one or four DFB as well as one that contained three SN-38 moieties and one DFB. Uptake and associated kinetic parameters of the 89Zr-labeled nanocarriers was determined in tumor and normal tissues in mice using μPET/CT imaging. The data were fit to physiologically-based pharmacokinetic models to simulate the mass-time profiles of distribution of conjugates in the tissues of interest. The time activity curves for normal tissues showed high levels at the earliest time of measurement due to vascularization, followed by a monophasic loss. In tumors, levels were initially lower than in normal tissues but increased to 9 to 14% of injected dose over several days. The efflux half-life in tumors was a very long ~400 h. and tumor levels remained at about 10% ID nine days after injection. Compared to diagnostic liposomes, the PEG nanocarriers have a longer serum half-life, are retained in tumors at higher levels, remain there longer, and afford higher tumor exposure. The small PEG40kDa nanocarriers studied here show properties for passive targeting of tumors that are superior than most nanoparticles and might be effective probes to identify tumors susceptible to a similar size therapeutic nanocarriers such as PLX038.
关键词： nanoparticle,imaging,Enhanced permeability and retention,tumor,pharmacokinetics,theranostics
更新于2025-09-23 15:19:57
-
Expression patterns of endothelial permeability pathways in the development of the blood-retinal barrier in mice
摘要： Insight into the molecular and cellular processes in blood-retinal barrier (BRB) development, including the contribution of paracellular and transcellular pathways, is still incomplete but may help to understand the inverse process of BRB loss in pathologic eye conditions. In this comprehensive observational study, we describe in detail the formation of the BRB at the molecular level in physiologic conditions, using mice from postnatal day (P)3 to P25. Our data indicate that immature blood vessels already have tight junctions at P5, before the formation of a functional BRB. Expression of the endothelial cell-specific protein plasmalemma vesicle-associated protein (PLVAP), which is known to be involved in transcellular transport and associated with BRB permeability, decreased during development and was absent when a functional barrier was formed. Moreover, we show that PLVAP deficiency causes a transient delay in retinal vascular development and changes in mRNA expression levels of endothelial permeability pathway proteins.
关键词： transcellular permeability,tight junctions,VEGF signaling
更新于2025-09-19 17:15:36
-
Applications of indocyanine green based near-infrared fluorescence imaging in thoracic surgery
摘要： Near-infrared (NIR) fluorescence guided surgery is an emerging technique. This technique uses the combination of dyes and NIR imaging devices to expand the visible spectrum. Thus it can provide more anatomic and functional information, and may facilitate a more complete resection of cancer, or better protection of important normal structures. Recently, significant progress has been made in the field of NIR fluorescence guided thoracic surgery. This may lead to better prognosis and health-economic outcomes. In this article, the current studies of indocyanine green (ICG) based NIR fluorescence guided thoracic surgeries are reviewed. The applications are classified into four categories, which are applications based on blood supply, lymphatic drainage, the enhanced permeability and retention (EPR) effect, and the other mechanisms.
关键词： lymphatic drainage,enhanced permeability and retention effect (EPR effect),indocyanine green (ICG),Near-infrared fluorescence,blood supply
更新于2025-09-19 17:15:36
-
Small but powerful: Light-emitting diodes for inactivation of Aspergillus species in real water matrices
摘要： This study addressed the effectiveness of light emitting diodes to achieve inactivation of three different Aspergillus species (Aspergillus fumigatus, Aspergillus niger and Aspergillus terreus) in a real water matrix. Three single small ultraviolet-C diodes emitting light at two different wavelengths were tested: 255 nm that is similar to the wavelength emitted by low pressure mercury lamps and 265 nm that is closer to the maximum absorbance wavelength of DNA. The ultraviolet-C diodes emitting light at 265 nm were found to be more effective than the 255 nm, achieving 3-log, 1-log and 5-log inactivations of Aspergillus fumigatus, Aspergillus niger and Aspergillus terreus using less than 20 mJ/cm2 (13,97 mJ/cm2; 7,28 mJ/cm2; 19,74 mJ/cm2). The diodes have also affected the morphology of the fungal spores and increased the percentage of damaged and dead spores.
关键词： Aspergillus species,Membrane permeability,Enzymatic activity,Light emitting diodes,Spores morphology,Disinfection
更新于2025-09-19 17:13:59
-
[IEEE 2019 Photonics North (PN) - Quebec City, QC, Canada (2019.5.21-2019.5.23)] 2019 Photonics North (PN) - Unassisted Artificial Photosynthesis using GaN-alloys Scaling up Ga(In)N Nanowire Synthesis for Large-scale Water Splitting under Real Sunlight
摘要： A novel one-port probe technique, which combines the measurements of a rectangular waveguide and coaxial probe to nondestructively yield the permittivity and permeability of a PEC-backed material, is presented. A brief description of the derivation of the theoretical probe reflection coefficients, necessary for permittivity and permeability extraction via numerical inversion, is provided. Experimental characterization results of a PEC-backed magnetic material are presented to validate the proposed approach. Error analysis is also undertaken to quantify the new technique’s sensitivity to common experimental errors.
关键词： Integral equations,measurement uncertainty,uncertainty,moment methods,permeability measurement,permittivity measurement,waveguides,microwave measurements
更新于2025-09-19 17:13:59