keyword
MENU ▼
Read by QxMD icon Read
search

Dielectric

keyword
https://www.readbyqxmd.com/read/28433897/low-temperature-microwave-assisted-pyrolysis-of-wood-sawdust-for-phenolic-rich-compounds-kinetics-and-dielectric-properties-analysis
#1
Hu Luo, Liwei Bao, Lingzhao Kong, Yuhan Sun
Microwave-assisted pyrolysis of wood sawdust for phenolic rich compounds was carried out between 400 and 550°C in a batch reactor. An efficient preparation of liquid products was observed at 500°C with a yield of 58.50%, which was similar to conventional fast pyrolysis. The highest concentration of phenolic compounds in liquid product reached up to 78.7% (area) in which the alkoxy phenols contributed 81.8% at 500°C. Microwave thermogravimetric analysis using KAS method was used firstly to investigate the low-temperature pyrolytic behaviors and activation energy...
April 9, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28433033/model-for-the-alpha-and-beta-shear-mechanical-properties-of-supercooled-liquids-and-its-comparison-to-squalane-data
#2
Tina Hecksher, Niels Boye Olsen, Jeppe C Dyre
This paper presents data for supercooled squalane's frequency-dependent shear modulus covering frequencies from 10 mHz to 30 kHz and temperatures from 168 K to 190 K; measurements are also reported for the glass phase down to 146 K. The data reveal a strong mechanical beta process. A model is proposed for the shear response of the metastable equilibrium liquid phase of supercooled liquids. The model is an electrical equivalent-circuit characterized by additivity of the dynamic shear compliances of the alpha and beta processes...
April 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28432354/structural-and-functional-analysis-of-lysozyme-after-treatment-with-dielectric-barrier-discharge-plasma-and-atmospheric-pressure-plasma-jet
#3
Sooho Choi, Pankaj Attri, Inhwan Lee, Jeongmin Oh, Ji-Hye Yun, Ji Hoon Park, Eun Ha Choi, Weontae Lee
The variation in the biological function of proteins plays an important role in plasma medicine and sterilization. Several non-thermal plasma sources with different feeding gases are used worldwide for plasma treatment, including dielectric barrier discharge (DBD) and atmospheric-pressure plasma jet (APPJ) as the most commonly used sources. Therefore, in the present work, we used both DBD and APPJ plasma sources with N2 and air as feeding gases to evaluate the effects on the structural, thermodynamic, and activity changes of enzymes...
April 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28432331/nontrivial-nonradiating-all-dielectric-anapole
#4
Nikita A Nemkov, Ivan V Stenishchev, Alexey A Basharin
Dynamic anapole is a promising element for future nonradiating devices, such as cloaked sources and sensors, quantum emitters, and especially the sources for observing dynamic Aharonov-Bohm effect. However, the anapole response can be damped by the Joule losses. In this paper we theoretically propose and experimentally demonstrate a novel type of active all-dielectric source, which is in some sense, realizes the elementary anapole of Afanasiev, and study its radiative/nonradiative regimes in the microwave range...
April 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28431459/direct-growth-of-al2o3-on-black-phosphorus-by-plasma-enhanced-atomic-layer-deposition
#5
B B Wu, H M Zheng, Y Q Ding, W J Liu, H L Lu, P Zhou, L Chen, Q Q Sun, S J Ding, David W Zhang
Growing high-quality and uniform dielectric on black phosphorus is challenging since it is easy to react with O2 or H2O in ambient. In this work, we have directly grown Al2O3 on BP using plasma-enhanced atomic layer deposition (PEALD). The surface roughness of BP with covered Al2O3 film can reduce significantly, which is due to the removal of oxidized bubble in BP surface by oxygen plasma. It was also found there is an interfacial layer of PO x in between amorphous Al2O3 film and crystallized BP, which is verified by both X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) measurements...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28431331/dielectric-properties-of-a-novel-colloidal-oral-matrix-drug-carrier
#6
Alexander Vol, Orna Gribova, Oded Shamir, Evgeniya Levy, Paul Ben Ishai, Anna Greenbaum Gutina, Yuri Feldman
Dielectric Spectroscopy (DS) was employed to study a novel oral matrix carrier (OMC), composed from silica nano-particles, polysaccharides, biopolymers and natural oils. This composition self-orders to a multi hierarchal structure and as such is amenable to be studied by techniques such as DS. The dielectric properties were measured in the frequency range 1MHz-1GHz and a temperature range 10°C-45°C. The results were dominated by two relaxation processes following CC relaxation and having relaxation times that are Arrhenius in nature...
April 12, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28431194/closed-form-equation-to-estimate-the-dielectric-properties-of-biological-tissues-as-a-function-of-age
#7
Beadaa Mohammed, Konstanty Bialkowski, Amin Abbosh, Paul C Mills, Andrew P Bradley
Developing microwave systems for biomedical applications requires accurate dielectric properties of biological tissues for reliable modeling before prototyping and subject testing. Dielectric properties of tissues decrease with age due to the change in their water content, but there are no detailed age-dependent data, especially for young tissue-like newborns, in the literature. In this article, an age-dependent formula to predict the dielectric properties of biological tissues was derived. In the proposed method, the variation of water concentration in each type of tissue as a function of age was used to calculate its relative permittivity and conductivity...
April 21, 2017: Bioelectromagnetics
https://www.readbyqxmd.com/read/28430499/bc8-silicon-si-iii-is-a-narrow-gap-semiconductor
#8
Haidong Zhang, Hanyu Liu, Kaya Wei, Oleksandr O Kurakevych, Yann Le Godec, Zhenxian Liu, Joshua Martin, Michael Guerrette, George S Nolas, Timothy A Strobel
Large-volume, phase-pure synthesis of BC8 silicon (Ia3[over ¯], cI16) has enabled bulk measurements of optical, electronic, and thermal properties. Unlike previous reports that conclude BC8-Si is semimetallic, we demonstrate that this phase is a direct band gap semiconductor with a very small energy gap and moderate carrier concentration and mobility at room temperature, based on far- and midinfrared optical spectroscopy, temperature-dependent electrical conductivity, Seebeck and heat capacity measurements...
April 7, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28430440/insights-on-the-physical-state-reached-by-an-active-pharmaceutical-ingredient-upon-high-energy-milling
#9
Benjamin Schammé, Xavier Monnier, Nicolas Couvrat, Laurent Delbreilh, Valérie Dupray, Eric Dargent, Gérard Coquerel
In this article, we study the physicochemical transformations of crystalline Quinidine upon high-energy milling. The investigations have been achieved by classical, high performance and fast scanning calorimetry combined with broadband dielectric spectroscopy and X-ray powder diffraction. As evolution of crystalline Quinidine with time of milling revealed a prominent sub-Tg cold-crystallization phenomenon, independent and complementary analytical techniques were implemented. Fast scanning calorimetry was performed for the first time on a milled pharmaceutical compound to postpone the crystallization event to higher temperatures...
April 21, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28430436/time-domain-thz-spectroscopy-reveals-coupled-protein-hydration-dielectric-response-in-solutions-of-native-and-fibrils-of-human-lysozyme
#10
Fabio Novelli, Saeideh Ostovar Pour, Jonathan O Tollerud, Ashkan Roozbeh, Dominique R T Appadoo, Ewan W Blanch, Jeffrey A Davis
Here we reveal details of the interaction between human lysozyme proteins, both native and fibrils, and their water environment by intense terahertz time domain spectroscopy. With the aid of a rigorous dielectric model, we determine the amplitude and phase of the oscillating dipole induced by the THz field in the volume containing the protein and its hydration water. At low concentrations, the amplitude of this induced dipolar response decreases with increasing concentration. Beyond a certain threshold, marking the onset of the interactions between the extended hydration shells, the amplitude remains fixed but the phase of the induced dipolar response, which is initially in phase with the applied THz field, begins to change...
April 21, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28430270/atomistic-non-adiabatic-dynamics-of-the-lh2-complex-with-a-gpu-accelerated-ab-initio-exciton-model
#11
Aaron Sisto, Clem Stross, Marc W van der Kamp, Michael O'Connor, Simon McIntosh-Smith, Graham T Johnson, Edward G Hohenstein, Fred R Manby, David R Glowacki, Todd J Martinez
We recently outlined an efficient multi-tiered parallel ab initio excitonic framework that utilizes time dependent density functional theory (TDDFT) to calculate ground and excited state energies and gradients of large supramolecular complexes in atomistic detail - enabling us to undertake non-adiabatic simulations which explicitly account for the coupled anharmonic vibrational motion of all the constituent atoms in a supramolecular system. Here we apply that framework to the 27 coupled bacterio-chlorophyll-a chromophores which make up the LH2 complex, using it to compute an on-the-fly nonadiabatic surface-hopping (SH) trajectory of electronically excited LH2...
April 21, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28430259/impact-of-assisting-atmospheric-pressure-plasma-on-the-formation-of-micro-and-nanoparticles-during-picosecond-laser-ablation-of-titanium
#12
Stefan Grottker, Wolfgang Viöl, Christoph Gerhard
In this work, we investigated the generation of particles during pure laser and plasma-assisted laser ablation of titanium. Experiments were performed using a NIR picosecond laser at a wavelength of 1030 nm and a pulse duration of 8 ps. For plasma-assisted ablation, an atmospheric pressure dielectric barrier discharge plasma was applied where the process gas was argon. Quantitative particle distributions at sizes from 10 nm to 10 μm were determined. In addition, we evaluated the amount of ablated material via laser scanning microscopy...
April 20, 2017: Applied Optics
https://www.readbyqxmd.com/read/28430248/accurate-determination-of-dielectric-permittivity-of-polymers-from-75%C3%A2-%C3%A2-ghz-to-1-6%C3%A2-%C3%A2-thz-using-both-s-parameters-and-transmission-spectroscopy
#13
Tianying Chang, Xiansheng Zhang, Xiaoxuan Zhang, Hong-Liang Cui
Interactions of terahertz (THz) electromagnetic radiation with polymer materials have been studied recently with increasing depth and breadth, for purposes of both using polymers in fabricating THz optical components such as lenses, waveplates, waveguides, and sample holders/containers, and employing THz spectral imaging as a new tool for nondestructive testing of polymer composite structures. Either endeavor cannot even begin without a quantitative knowledge of the complex dielectric permittivity, i.e., the propagation and attenuation properties of such polymers in the requisite wave band...
April 20, 2017: Applied Optics
https://www.readbyqxmd.com/read/28430216/ultrahigh-birefringence-ultralow-material-loss-porous-core-single-mode-fiber-for-terahertz-wave-guidance
#14
Kawsar Ahmed, Sawrab Chowdhury, Bikash Kumar Paul, Md Shadidul Islam, Shuvo Sen, Md Ibadul Islam, Sayed Asaduzzaman
In this paper, a novel polarization-maintaining single-mode photonic crystal fiber (PCF) has been suggested for terahertz (THz) transmission applications. The reported PCF has five layers of hexagonal cladding with two layers of porous core. The cladding and core territory of the PCF are constituted by circular and elliptical air cavities, accordingly acting as a dielectric medium. Different geometrical parameters of the proposed PCF including pitches and diameters of circular air holes with the major and minor axes of elliptical air cavities being varied with the optimized structure...
April 20, 2017: Applied Optics
https://www.readbyqxmd.com/read/28428625/recovery-of-alumina-nanocapacitors-after-high-voltage-breakdown
#15
A Belkin, A Bezryadin, L Hendren, A Hubler
Breakdown of a dielectric material at high electric fields significantly limits the applicability of metal-dielectric-metal capacitors for energy storage applications. Here we demonstrate that the insulating properties of atomic-layer-deposited Al2O3 thin films in Al/Al2O3/Al trilayers can recover after the breakdown. The recovery has been observed in samples with the dielectric thickness spanning from 4 to 9 nm. This phenomenon holds promise for a new generation of capacitors capable of restoring their properties after the dielectric breakdown...
April 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28428549/low-noise-time-resolved-optical-sensing-of-electromagnetic-pulses-from-petawatt-laser-matter-interactions
#16
T S Robinson, F Consoli, S Giltrap, S J Eardley, G S Hicks, E J Ditter, O Ettlinger, N H Stuart, M Notley, R De Angelis, Z Najmudin, R A Smith
We report on the development and deployment of an optical diagnostic for single-shot measurement of the electric-field components of electromagnetic pulses from high-intensity laser-matter interactions in a high-noise environment. The electro-optic Pockels effect in KDP crystals was used to measure transient electric fields using a geometry easily modifiable for magnetic field detection via Faraday rotation. Using dielectric sensors and an optical fibre-based readout ensures minimal field perturbations compared to conductive probes and greatly limits unwanted electrical pickup between probe and recording system...
April 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28426077/robust-raspberry-like-metallo-dielectric-nanoclusters-of-critical-sizes-as-sers-substrates
#17
A Le Beulze, S Gomez-Graña, H Gehan, S Mornet, S Ravaine, M Correa-Duarte, L Guerrini, R A Alvarez-Puebla, E Duguet, E Pertreux, A Crut, P Maioli, F Vallée, N Del Fatti, O Ersen, M Treguer-Delapierre
Raspberry-like nano-objects made of large plasmonic satellites (>10 nm) covering a central dielectric particle have many potential applications as photonic materials, superlenses and (bio-) sensors, but their synthesis remains challenging. Herein, we show how to build stable and robust raspberry-like nano-systems with close-packed satellites, by combining monodisperse silica particles (80 or 100 nm diameter) and oppositely charged noble metal nanoparticles (Au or Ag) with well-defined sizes (10-50 nm). The spectral characteristics of their associated plasmonic resonances (wavelength, linewidth, extinction cross-section) and the electromagnetic coupling between satellites were observed using the spatial modulation spectroscopy technique and interpreted through a numerical model...
April 20, 2017: Nanoscale
https://www.readbyqxmd.com/read/28426068/amplification-of-the-molecular-chiroptical-effect-by-low-loss-dielectric-nanoantennas
#18
Weixuan Zhang, Tong Wu, Rongyao Wang, Xiangdong Zhang
We report here the chiroptical amplification effect occurring in the hybrid systems consisting of chiral molecules and Si nanostructures. Under resonant excitation of circularly polarized light, the hybrid systems show strong CD induction signals at the optical frequency, which arise from both the electric and magnetic responses of the Si nanostructures. More interestingly, the induced CD signals from Si-based dielectric nanoantennas are always larger than that from Au-based plasmonic counterparts. The related physical origin was disclosed...
April 20, 2017: Nanoscale
https://www.readbyqxmd.com/read/28426064/dual-stimuli-triggered-dielectric-switching-and-sensing-in-a-host-guest-cyanometallate-framework
#19
Yu-Ling Liu, Wen Zhang
The host-guest hybrid cyanometallate framework (MA)(H2O)[Sr(H2O)2Co(CN)6] (1; MA = methylammonium) shows thermally and chemically triggered dielectric switching and sensing via a temperature-driven phase transition and a water-driven reversible structure transformation between 1 and its dehydrated form (MA)[SrCo(CN)6].
April 20, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28425529/influence-of-cations-in-lithium-and-magnesium-polysulphide-solutions-dependence-of-the-solvent-chemistry
#20
Georg Bieker, Julia Wellmann, Martin Kolek, Kirsi Jalkanen, Martin Winter, Peter Bieker
In order to gain a deeper understanding of Li and Mg polysulphides in Li/S and Mg/S batteries, respectively, this work investigates the impact of the two different cations as well as the influence of the electrolyte solvents' relative dielectric permittivity and Gutmann's donor number on the solubility and relative stability of different Li and Mg polysulphide species. Therefore, the disproportionation and dissociation equilibria of chemically prepared "Li2S8" and "MgS8" solutions in DMSO, DMF, ACN, THF, DME, TEGDME, and Pyr14TFSI are characterized by UV/Vis spectroscopy...
April 20, 2017: Physical Chemistry Chemical Physics: PCCP
keyword
keyword
17371
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"