Search results for " Glass"

Modelling of electromagnetic heating and mixing conditions in glass melt output equipment

2011

PurposeThe purpose of this paper is to investigate the outlet of a special glass melting system, which is used to control melt flow and modify flow pattern.Design/methodology/approachNumerical calculations in ANSYS and ANSYS CFX were used to study electromagnetic, thermal, hydrodynamic and chemical mixing processes, results are validated by comparison with experimental data.FindingsObtained results show that investigated approach can improve glass melt chemical homogeneity significantly – Lorentz force driven melt movement in conjunction with diffusion process ensures good mixing quality.Research limitations/implicationsThe mixing in glass melt is present only in azimuthal direction (in cyl…

TCO/Ag/TCO transparent electrodes for solar cells application

2014

Among transparent electrodes, transparent conductive oxides (TCO)/metal/TCO structures can achieve optical and electrical performances comparable to, or better than, single TCO layers and very thin metallic films. In this work, we report on thin multilayers based on aluminum zinc oxide (AZO), indium tin oxide (ITO) and Ag deposited by RF magnetron sputtering on soda lime glass at room temperature. The TCO/Ag/TCO structures with thicknesses of about 50/10/50 nm were deposited with all combinations of AZO and ITO as top and bottom layers. While the electrical conductivity is dominated by the Ag intralayer irrespective of the TCO nature, the optical transmissions show a dependence on the natur…

Lithographic fabrication of soda-lime glass based microfluidics

2013

Abstract Glass is an important material for chemical processing and analysis because of its relatively low cost, mechanical strength, chemical inertness, optical transparency, and electrical insulation and temperature resistance far beyond that of most polymeric materials. We have investigated techniques for direct writing with MeV ions on soda-lime glass as well as capping procedures to form closed buried channels suitable for high-pressure driven flow. Exposure and development of open-channel structures was studied using a combination of programmable proximity aperture lithography and different developers. Unlike our previous work on MeV ion beam lithography of natural silica where an 8% …

The effects of solar radiation in archaeological sites

2013

Ruined walls, paving and decorative elements of archaeological sites are mainly composed of materials with chemical, physical and biological degradation problems that are primarily due to environmental factors. The conservation of archaeological finds requires a protection against these factors. Solar radiation may constitute one of those causes of deterioration. In recent decades the use of glass to cover archaeological sites has been more and more widespread (Fig. 1). The purpose of those glass covers is to reconcile the need of the display capabilities with the preservation of the remains. In general, a protective cover structure determines new conditions that must be carefully controlle…

1980

Molecular weights of Trogamid T® were determined by ultracentrifugation, light-scattering, osmometry and viscometry, molecular weight distributions by gel permeation chromatography (GPC) and five different fractionation methods. The separation efficiency of GPC with N,N-dimethylformamide as solvent was tested with three different types of gels, crosslinked polystyrene, porous glass and crosslinked poly(vinyl acetate), the last one yielding the best results. Solution fractionations show better results than precipitation methods. All fractionations gave far too small apparent non-uniformities. After correction according to the non-uniformities of the fractions the results corresponded to thos…

Novel photoreception system in sponges?

2006

Abstract Sponges (phylum Porifera) of the classes Hexactinellida and Demospongiae possess a skeleton composed of siliceous spicules, which are synthesized enzymatically. The longest spicules are found among the Hexactinellida, with the stalk spicules (length: 30 cm; diameter: 300 μm) of Hyalonema sieboldi as prominent examples. These spicules are constructed around a central axial filament, which is formed by approximately 40 siliceous layers. The stratified spicules function as optical glass fibers with unique properties. If free-spaced coupled with a white light source (WLS), the entire fiber is illuminated. Special features of the light transmission: (i) only wavelengths between 615 and …

Spontaneous Magnetization in Ni−Al and Ni−Fe Layered Double Hydroxides

2008

Layered double hydroxides containing paramagnetic Ni (II) and diamagnetic/paramagnetic Al (III)/Fe (III) ions have been prepared and characterized. Ni 2Al(OH) 6(NO 3). nH 2O ( 1), Ni 2Fe(OH) 6(NO 3). nH 2O ( 2), Ni 2Fe(OH) 6(C 6H 8O 4) 0.5. nH 2O ( 3), and Ni 2Fe(OH) 6(C 10H 16O 4) 0.5. nH 2O ( 4) were prepared by coprecipitation at controlled pH as polycrystalline materials with the typical brucite-like structure, with alternating layers of hydroxide and the corresponding anions, which determine the interlayer separation. Magnetic studies show the appearance of spontaneous magnetization between 2 and 15 K for these compounds. Interestingly, the onset temperature for spontaneous magnetizati…

Magnetic susceptibility of multiferroics and chemical ordering

2017

Magnetic susceptibility of two types of perovskite compounds A(Fe0.5M0.5)O3 A=Ba,Sr with M=Nb and Sb differing in the degree of chemical ordering was studied between 2 and 380 K. In the low temperature region, these compounds exhibit antiferromagnetic and spin-glass transition at T = 16−30 K. For the ordered compounds (M = Sb) the inverse susceptibility depends on T linearly up to the highest temperatures used. This enables the determination of the Weiss temperature θ and effective moment of the Fe3+ ion expressed by a number of Bohr magnetons, peff. In contrast to it, the compounds with M = Nb are characterized by a higher degree of the glassines and by a concave character of the inverse s…

Magnetic Ordering and Spin Dynamics of Ba1-xEuxSi Phases

2011

We have investigated the magnetic ordering and spin dynamics of the solid solution series Ba1–xEuxSi with 0 < x ≤ 1 applying X-ray diffraction, electric conductivity measurements, Mossbauer spectroscopy, muon spin depolarization, and neutron diffraction. Our results suggest a spin glass-like behavior of Ba1–xEuxSi for concentrations close to x = 0.3 exist. Different spin ordering phenomena are found, which are dependent on the relative europium concentrations.

Static and dynamic glass transitions in the 10-state Potts glass: What can Monte Carlo simulations contribute?

2002

The p-state Potts glass with infinite range Gaussian interactions can be solved exactly in the thermodynamic limit and exhibits an unconventional phase behavior if p >4: A dynamical transition from ergodic to non-ergodic behavior at a temperature T D is followed by a first order transition at T 0 < T D, where a glass order parameter appears discontinuously, although the latent heat is zero. If one assumes that a similar scenario occurs for the structural glass transition as well (though with the singular behavior at T D rounded off), the p-state Potts glass should be a good test case to develop methods to deal with finite size effects for the static as well as the dynamic transition, and to…