Potential Of Glasses Research Articles

Glass Fibre Reinforced Concrete (GFRC) Materials and Its Applications

In the 1940’s, potential of glass as a construction material was realized and improvement continued with the addition of zirconium dioxide in 1960's for harsh alkali conditions. The development of new glass fibre generations is focused on improving the process of material durability. In order to meet various needs, glass fibre reinforced concrete, or GFRC, was thus introduced into production. Research and experiments conducted on GFRC have demonstrated that the material quality and production precision have an impact on the material's mechanical and physical characteristics. GFRC can be applied anywhere an impermeable, weather-resistant, fire-resistant, light-weight, and robust material is required. With the development of technology, it may be possible to construct sophisticated freeform structures and entire buildings at a reasonable cost. Recently, research has been done on the impact of glass fibres in hybrid mixtures for high-performance concrete (HPC), a newly developed technology that is gaining popularity in the building sector.

Glass Fibre Reinforced Concrete (GFRC)

1940’lı yıllarda camın bir yapı malzemesi olarak sahip olduğu potansiyelinin farkına varılmış ve 1960’larda zirkonyum dioksit katkısıyla iyileştirmelere devam edilmiştir. Malzemelerin kimyasal dayanımını arttırmak için yeni nesil cam lifleri, söz konusu iyileştirme sürecine dâhil edilmişlerdir. Böylece, arzu edilen beklentileri karşılamak üzere cam takviyeli beton üretimi başlamıştır. Bu grup beton üzerine gerçekleştirilen bilimsel araştırma ve testler cam lifle kuvvetlendirilmiş betonun fiziksel ve mekanik özelliklerinin kullanılan malzemelerin kalitesine ve üretim yönteminin hassasiyetine bağlı olarak değiştiğini göstermiştir. Böylesi betonlar, hafif, sağlam, ateşe ve hava koşullarına karşı dayanıklı, sızdırmaz malzeme ihtiyacı doğduğunda kullanılabilirlik arz etmektedirler. Teknoloji ilerlerken bir binanın tamamının cam takviyeli betonlarla düşük maliyetle yapımının mümkün olabileceği beklentisi de artmaktadır. Geçtiğimiz yıllarda cam elyafların hibrid karışımlardaki etkisi yüksek performanslı beton elde etmek amacıyla araştırılmaya başlanmıştır. Bu yeni teknoloji inşaat sektöründe popüler hale gelmiştir.

Low Cost Glass Interposer Development

For high density interconnection IC packages of the future, the outlook is for thinner packages with higher routing densities. With that, managing the substrate warpage becomes critical. Traditional organic substrates may face several challenges for high density I/Os with very fine line interconnections. Glass is one of the candidates that can be used in substrate industry. The infrastructure of glass for LCD industry has already been developed for many years. Glass also has several superior properties than other substrate candidates, such as large panel size availability, adjustable CTE, high modulus, low dielectric constant, low dielectric loss and high insulating ability. In this paper, we successfully demonstrate early manufacturing feasibility of glass substrate with 4 build-up layers starting with a thin glass panel of thickness of 200μm in 508mm μ 508mm panel size format and under the IC substrate manufacturing environment. Fabrication and electrical results of a test vehicle are documented. The test vehicle includes daisy chains that are connected with 100μm diameter through glass via (TGV) in a 200μm thick glass. The laser via in via technology was adopted for double side electrical connection. The copper line width/space of 8/8μm was demonstrated. The total thickness of 4 layers test vehicle is about 390μm. The warpage of glass in comparison with an organic substrate (BT) with 200μm core thickness is 3X better. Further work is needed to develop, fine tune and assess the detailed manufacturability and reliability concerns. Based on this work, it is clear that the potential of glass in IC packaging and integration is tremendous in diverse applications for substrate warpage enhancement.

Effects Of Grp Wastes On The Properties Of Self-Compacting Repair Mortars

Self-compacting repair mortars (SCRM) can flow through the narrow sections without vibration requirement. This study is aimed to search the utilization potential of glass reinforced plastic (GRP) waste powders occurred during repairing ship and vessel. Six mixtures have been prepared with 1%, 2% and 3% GRP waste addition by volume into two different matrices including only cement binder as well as ground granulated blast furnace slag (GGBFS) replaced 50% wt. of the cement binder. Workability of SCRM decreased as a result of GRP waste utilization. GRP wastes have exhibited different mechanical performance and early age autogenous shrinkage depending on the binder. The increment in GRP dosage caused an increase in early age autogenous shrinkage for matrix involving only cement binder while it caused a decrease in autogenous shrinkage value of GGBFS replaced matrix.

Gamma-rays shielding properties of xPbO:(100 − x)B 2O 3 glasses system at 662 keV

The mass attenuation coefficients, total interaction cross-sections and effective atomic numbers of xPbO:(100 − x)B 2O 3 (where 30 ⩽ x ⩽ 70% weight) glass system have been investigated on the basis of the mixture rule. The results are good agreement with the theoretical values, calculated by WinXCom. Mass attenuation coefficients were increased with increase PbO content, due to increase effective atomic number of glass samples, which increase probability of photoelectric absorption in glass. However, Compton scattering gives dominant contribution to the total mass attenuation coefficients for studied glass samples. Their shielding properties of glass samples are also better than ordinary shielding concretes and commercial window glass which can be used with advantage as transparent in visible region. These results are indicating the potential of glasses in radiation shielding materials.

Pigment Spectra and Intermolecular Interaction Potentials in Glasses and Proteins

A model is proposed for chromophore optical spectra in solids over a wide range of temperatures and pressures. Inhomogeneous band shapes and their pressure dependence, as well as baric shift coefficients of spectral lines, selected by the frequency, were derived using Lennard-Jones potentials of the ground and excited states. Quadratic electron-phonon coupling constants, describing the thermal shift and broadening of zero-phonon lines, were also calculated. Experimentally, thermal shift and broadening of spectral holes were studied between 5 and 40 K for a synthetic pigment, chlorin, embedded in polymer hosts. The baric effects on holes were determined by applying hydrostatic He gas pressure up to 200 bar, at 6 K. Absorption spectra of pheophytin a, chlorophyll a, and β-carotene in polymers and plant photosystem II CP47 complex were measured between 5 (or 77) and 300 K, and subject to Voigtian deconvolution. A narrowing of inhomogeneous bandwidth with increasing temperature, predicted on the basis of hole behavior, was observed as the shrinking of Gaussian spectral component. The Lorentzian broadening was ascribed to optical dephasing up to 300 K in transitions with weak to moderate linear electron-phonon coupling strength. The thermal broadening is purely Gaussian in multiphonon transitions (S 2 band of β-carotene, Soret bands of tetrapyrrolic pigments), and the Lorentz process appears to be suppressed, indicating a lack of exponential dephasing. Density, polarity, polarizability, compressibility, and other local parameters of the pigment binding sites in biologically relevant systems can be deduced from spectroscopic data, provided that sufficient background information is available.

Interactions of soft atomic potentials and universality of low-temperature properties of glasses.

It is shown that the interaction between soft atomic potentials in glasses leads to a density of the low-energy tunneling states, P\ifmmode\bar\else\textasciimacron\fi{}, which does not depend on the concentration of defects. The dimensionless parameter P\ifmmode\bar\else\textasciimacron\fi{}${\ensuremath{\gamma}}^{2}$/\ensuremath{\rho}${\mathit{v}}^{2}$ which characterizes the interaction between two-level systems is estimated. It appears to be small in accordance with available experimental data. The theory developed allows us to understand both the insensitivity of low-temperature properties of glasses to the concentration of the defects (e.g., created by neutron irradiation) and the relatively small interaction between two-level systems. Making use of only three macroscopic material parameters, namely the mass density \ensuremath{\rho}, the sound velocity v, and the average value of the atomic mass M\ifmmode\bar\else\textasciimacron\fi{}, nearly correct values are obtained for the two-level systems' density of states P\ifmmode\bar\else\textasciimacron\fi{}, for the deformation potential \ensuremath{\gamma} and for other parameters describing the low-temperature properties of glasses. All of them appeared to be nearly the same for glassy systems. Thereby, the explanation of universality of the low-temperature properties of glasses is given.

Theory of low-energy Raman scattering in glasses.

We work out a theory of low-energy Raman scattering in glasses. The scattering and the energy transfer are due to interaction of the light with the soft potentials in glasses. We exploit relations between the scattering cross sections at a certain energy transfer, \ensuremath{\Elzxh}\ensuremath{\omega}, and the mean free paths of sound and electromagnetic radiation for the frequency \ensuremath{\omega}. A comparison between the theory and experiment is made. An explanation of the boson peak is proposed. We come to a conclusion that the peak may be due to a reconstruction of the low-energy density of states due to interaction between soft harmonic oscillators. The interaction is enhanced with the frequency \ensuremath{\omega} and, as a result, soft harmonic vibrations, localized for comparatively small \ensuremath{\omega}, become extended (but not propagated) for bigger values of \ensuremath{\omega}.

Critical behaviour of the double-well potentials in glasses

The Hamiltonian of the dangling-bond and void-like structure model, developed by the authors for the atomic tunneling states in glasses, is solved by the path integral theory. The theoretical result shows that an atom in a void will meet an effective potential with two phases: the double-well phase and the single-well phase, depending on the radius of the void. In the vicinity of the critical point, the behavior of the effective double-well potential is investigated and we find that: (i) the maximum energy of two-level systems (TLS) is about 15 K, (ii) the deformation potential is nearly independent of the energy of TLS. The numbers of TLS in a-Si is estimated and it is about ten times smaller than that in vitreous silica.

A cluster simulation of the double-well potentials in glasses

Double-well potential (DWP) is simulated in a cluster of SiO 2. The Si-O-Si chain is stretched until a DWP arises. Its parameters vs stretching are investigated. Some considerations in favour of two types of DWP in glasses are put forward.

Atomic critical potentials and structure of non-single-well potentials in glasses

The microscopic nature and structure of atomic local non-single-well potentials in amorphous materials are considered. It is shown that the nature of such potentials is related to the local potential instability in an appropriate critical mode of the atomic motion. The occurrence of critical potential with unusually small spring constants is predicted. Some simple microscopic models are discussed in detail. It is shown that the non-single-well potentials practically reduce to critical double-well potentials in real amorphous materials. Two different types of the double-well potentials in glasses are revealed. Some predictions are given for the distribution densities of the parameters describing tunneling states in the critical double-well potentials and for some effects in amorphous materials.