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The Aluminium 6063 have found wider applications in architectural fabrications, frames, pipe and tubing because of their intrinsic properties The Mechanical behavior of Aluminium alloy 6063 metal matrix composites (AMMC) reinforced with Borosilicate powder of 75 microns is investigated in this study. The Metal Matrix Composites (MMC’s) were prepared using various percentages of borosilicate reinforcements of 0, 2.5, 5, 7.5 and 10 % by wt. The main aim of the research was to determine the impact of borosilicate powder (75 microns) on the mechanical behavior of Al 6063. Mechanical tests such as tensile test, Vickers micro hardness measurements and compression tests were performed on the produced composite samples to determine the influence of the powder in the Aluminium alloy. The test results of the reinforced samples were compared with non-reinforced samples. By comparing all the test values it is inferred that AA 6063 has better properties when reinforced with 7.5% of 75micron size borosilicate reinforcements.

In the present study, an attempt has been made to study the influence of CaO/Mgo ratio (R) on different physical properties of (10+x)CaO-(10-x)-MgO-10SrO-10B2O3-20Al2O3-40SiO2 glasses. The novel glass series has been synthesized by melt quenching technique. The parameters like reflection loss and dielectric constant have been determined. Also, molar refraction, molar electronic polarizability and oxygen packing density have been calculated on the basis of measured values of density, molar volume and refractive index of the glasses.

Effect of TiO2 addition in Cs containing Sodium-borosilicate glasses is studied using Raman and infrared spectroscopic techniques. As revealed from infrared and Raman studies, TiO2 does not form segregated phase, but instead enters into the borosilicate network. It is further observed that TiO2 addition results in modifications of the borate and silicate structural units by transforming into tetraborates and metasilicate structural units. These structural modifications are responsible for Cs immobilization, leach rate and chemical durability of these glasses.

We investigate the impact of oxygen concentration during boron diffusion at peak temperatures varying from 875°C to 950°C using borosilicate glass layers (BSG) deposited by atmospheric pressure chemical vapor deposition (APCVD) as doping source. Therefore, we vary the boron concentration in the BSG layer and the oxygen concentration in the gaseous ambient of the high temperature step. We characterize the process combinations with respect to their resulting sheet resistance and charge carrier concentration profile. In addition, we perform quasi steady-state photoconductance measurements to investigate the influence of the process parameters on the recombination properties at the boron-diffused and passivated surface. Low saturation current densities J0 = 16 fA/cm2 (planar surface, Al2O3/SiNx passivation) are observed at a sheet resistance of Rsh = 121 Ω/sq at peak temperature Tpeak = 875°C. Finally, we show that the oxygen concentration is a crucial parameter to prevent the formation of a boron rich layer at the silicon surface. This parameter needs to be selected carefully, as too high oxygen concentrations lead to complete decoupling of the doping source, depending on boron concentration and process temperature.

Bioactive glass-ceramics 45.8 mol% SiO– 45.8 CaO – 8.4 B2O3 doped with Ag2O were synthesized by sol-gel method. The glass-ceramic nature of samples was confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis. Fourier transform infrared (FT-IR) spectra reveal the probable stretching and bending vibration modes of silicate and borate groups. UV-Visible spectra reveal the presence of Ag+ ions and metallic Ag in the glass matrix for Ag2O doped ceramic sample. Biocompatibility of the glass nature of samples was studied by soaking of samples in Dulbecco’s Modified Eagle’s Medium (DMEM) with subsequent XRD studies. It was found that bone-like apatite formation on the glasses after soaked in DMEM. Antibacterial studies of glass ceramics powder against gram positive and negative microorganisms were carried out.Bioactive glass-ceramics 45.8 mol% SiO– 45.8 CaO – 8.4 B2O3 doped with Ag2O were synthesized by sol-gel method. The glass-ceramic nature of samples was confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis. Fourier transform infrared (FT-IR) spectra reveal the probable stretching and bending vibration modes of silicate and borate groups. UV-Visible spectra reveal the presence of Ag+ ions and metallic Ag in the glass matrix for Ag2O doped ceramic sample. Biocompatibility of the glass nature of samples was studied by soaking of samples in Dulbecco’s Modified Eagle’s Medium (DMEM) with subsequent XRD studies. It was found that bone-like apatite formation on the glasses after soaked in DMEM. Antibacterial studies of glass ceramics powder against gram positive and negative microorganisms were carried out.

During the last few decades, the increasing demands in esthetic dentistry have led to the development of dental composites material that provide similar appearance to the natural teeth. Recently, esthetic trend was an issue which increase the demand for teeth restorations that is similar with the origin. The esthetics of dental composite are more superior compared to amalgam, since its color look similar with natural teeth. Various dental composites have been developed using many type of fillers such as amorphous silica, quartz), borosilicate, Li-Sr-Ba-Al glass and oxide: zirconia and alumina. Researchers in Faculty of Dentistry University of Padjadjaran have prepared dental composites using zirconia-alumina-silica (ZAS) system as the filler. The aim is to improve the mechanical properties and the esthetic of the dental composites. The ZAS was obtained from chemical grade purity chemicals and Indonesia’s natural sand as precursors its characterization were also presented. This novel method covers the procedure to synthesis and characterize dental composites in Padjadjaran University and some review about dental composites in global research.

This study focuses on the properties of ZTO which have been deposited by a low-cost method namely aerosol assisted chemical vapor deposition (AACVD). The precursors used in this method were zinc acetate dihidrate and tin chloride dihydrate for ZTO thin film deposition. Both precursors were mixed and stirred until fully dissolved before deposition. The ZTO was deposited on borosilicate glass substrate for the investigation of optical properties. The films deposited have passed the scotch tape adherence test. XRD revealed that the crystal ZTO is slightly in the form of perovskite structure but several deteriorations were also seen in the spectrum. The UV-Vis analysis showed high transmittance of ∼85% and the band gap was calculated to be 3.85 eV. The average thickness of the film is around 284 nm. The results showed that the ZTO thin films have been successfully deposited by the utilization of AACVD method.

The study of sorption and transport characteristics of a composite sorbent based on various types of glass microspheres is carried out. In order to carry out this research, an experimental stand has been prepared for measuring sorbent characteristics at specified pressure and temperature values. The technique of carrying out the experiment and processing the experimental data for the purpose of determining the helium permeability of composite sorbents with a filler made of different material: sodium borosilicate glass, silica microspheres, cenospheres has been worked out. The values of the helium permeability of the composite sorbent in the temperature range from 20 to 140 °C are determined. The transport characteristics of the medium formed by the granules of the composite sorbent, as well as the values of the characteristic time of helium sorption by the composite sorbent are found.

Symmetric plate-impact tests of borosilicate glass were performed from low (116 m/s) to higher (351 m/s) velocities. The tests were recorded with an ultra-high-speed camera to see the shock and failure propagation. The velocity of the back of the target was also recorded with a PDV (Photon Doppler Velocimeter). The images show failure nucleation sites that trail the shock wave. Interestingly, even though the failure wave is clearly seen, the PDV never detected the expected recompression wave. The reason might be that at these low impact velocities the recompression wave is too small to be seen and is lost in the noise. This work also presents a new way to interpret the signals from the PDV. By letting part of the signal travel through the target and reflect on the impact side, it is possible to see the PDV decrease in intensity with time, probably due to the damage growth behind the shock wave.

The corrosion behaviors of Inconel 601 in the borosilicate glass (MW glass) containing 25 wt.% of simulant Magnox waste, and in ZnO, Mn2O3 and Fe2O3 modified Mg/Ca borosilicate glasses (MZMF and CZMF glasses) containing 15 wt.% of simulant POCO waste, were evaluated by dimensional changes, the formation of internal defects and changes in alloy composition near corrosion surfaces. In all three kinds of glass melts, Cr at the inconel surface forms a protective Cr2O3 scale between the metal surface and the glass, and alumina precipitates penetrate from the metal surface or formed in-situ. The corrosion depths of inconel 601 in MW waste glass melt are greater than those in the other two glass melts. In MW glass, the Cr2O3 layer between inconel and glass is fragmented because of the reaction between MgO and Cr2O3, which forms the crystal phase MgCr2O4. In MZMF and CZMF waste glasses the layers are continuous and a thin (Zn, Fe, Ni, B)-containing layer forms on the surface of the chromium oxide layer and preven...

Finely grinded waste glass powder can become material having suitable properties from the point of view of particle size and pozzolanic activity. Glass powder incorporation into cement paste and cement-based composites can bring improvement in porous structure resulting in increased mechanical strength and durability characteristics. On this account, two types of recycled glass powder are investigated in the presented paper as a possible partial Portland cement substitutes in cement blends. For raw glass powders, basic physical parameters and chemical composition are measured. The studied glass powders are applied as 5, 10 and 20 mass% of Portland cement replacement in cement paste mix composition, whereas water/binder ratio of 0.3 is used for all studied pastes. Fresh paste mixtures are characterized using initial and final setting time measurement. For hardened pastes cured 28 days in water, bulk density, matrix density, total open porosity and mechanical properties represented by flexural and compressive strength are accessed. Portlandite consumption by the pozzolanic reaction is monitored with TGA. The obtained results show effectiveness of a borosilicate glass powder that acts as a pozzolanic active admixture. This resulted in improvement of mechanical characteristics for cement substitution up to 10 mass%.Finely grinded waste glass powder can become material having suitable properties from the point of view of particle size and pozzolanic activity. Glass powder incorporation into cement paste and cement-based composites can bring improvement in porous structure resulting in increased mechanical strength and durability characteristics. On this account, two types of recycled glass powder are investigated in the presented paper as a possible partial Portland cement substitutes in cement blends. For raw glass powders, basic physical parameters and chemical composition are measured. The studied glass powders are applied as 5, 10 and 20 mass% of Portland cement replacement in cement paste mix composition, whereas water/binder ratio of 0.3 is used for all studied pastes. Fresh paste mixtures are characterized using initial and final setting time measurement. For hardened pastes cured 28 days in water, bulk density, matrix density, total open porosity and mechanical properties represented by flexural and compressi...

Fused borosilicate/vinyl ester syntactic foams mostly used for thermal stability in many applications are considered to be characterised for their properties in higher temperature condition. Therefore, higher temperature characteristics need to be explored with respect to physical parameters such as porosity and void content. The filler, also known as glass microballoons, was incorporated in vinyl ester resin matrix in 2wt%, 4wt%, 6wt.% , 8wt.% and 10wt.%. These composites are characterised and degraded to examine the onset temperature, Tonset, peak temperature, Tpeak and end temperature, Tend using thermogravimetric analysis (TGA) method. The results for Tonset showed an increment while Tend and T peak showed decrement when glass microballoons were added in syntactic foams. Based on TGA data, they exhibited excellent thermal stability, showing 5% weight loss at 380-450oC. Glass transition temperature (Tg) decreased when more glass microballoons were added, and also related to the effect on the physical properties of syntactic foams. Therefore, understanding of the relationship between thermal properties of syntactic foams and their physical properties such as porosity and void content will help in developing syntactic foams to optimise their thermal characteristics, which will be beneficial for engineering applications.

V2O5 doped sodium barium borosilicate glasses were characterized by photoluminescence spectroscopy and electron probe microanalyzer (EPMA). The glass remains homogeneous for lower concentration of V2O5 but a phase separation is observed when V2O5 doping is increased beyond 5 mol%. Detailed microanalysis reveals that the phase separated glass consists of a phase containing V, Ba and Si and a separate Si rich phase within the glass matrix. The luminescence study demonstrated that at low concentration the vanadium mainly interacts with the structural units of B/Si while at higher concentrations, V-O-V/ V-O− Na+/Ba2+ linkages are formed.

Lead borosilicate (LBS) glasses incorporated with europium (Eu3+) ions were synthesized using various chemical constituents. The structure of the glass matrix has been studied by experimental techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR), optical absorption (OA) and photoluminescence (PL) spectroscopy. From the XRD spectrum, several crystalline phases of LBS glass host were identified. The FTIR spectrum of the LBS glass host was recorded to investigate the local structural and functional groups. Due to the different characteristic nature of the Eu3+ ion, the absorption bands were observed from the ground (7F0) and the first excited (7F1) states. Further, Judd-Ofelt theory has been applied to compute the intensity parameters (Ωλ, λ = 2, 4 and 6) from the absorption intensities of 7F0 → 5D2 and 7F0 → 5L6 transitions, respectively. Characteristic emission bands are observed at 578, 592, 613,653 and 701 nm corresponding to 5D0 → 7F0, 7F1, 7F2, 7F3 and 7F4 transitions, respectiv...

Sol-gel technique was used for synthesis of Calcium phosphorous Borosilicate (CaO-SiO2-B2O3-P2O5-CuO-ZnO) glasses by varying composition of Copper oxide and Zinc oxide. Sol-gel route uses organic precursors which provide better homogeneity and uniform particle size compared to melt quenched glass. Four different glass stoichiometries were characterised using UV-visible spectroscopy and Fourier transforms infra-red spectroscopy (FTIR). Infra-red spectrum of transmittance of powdered glass samples is obtained by FTIR which measure the transmittance of wavelength in them and it also determines the presence of different functional group. Band gap has been obtained using UV-visible spectroscopy for all the glasses so as to study the effect of increasing ZnO content in glass composition. The change in band gap with ZnO content is indication of the change in number of non-bridging oxygen’s (NBO).

CaO-P2O5-ZnO-SiO2-B2O3 glasses with varying compositions of calcium oxide and phosphorous oxide are synthesized using sol-gel technique. The glasses are heat-treated for a duration of 10 h at 500°C to obtain the glass-ceramics. The glass-ceramics and glasses are characterized using Fourier transform infrared spectroscopy (FTIR) and UV-Visible spectroscopy. Extinction coefficients, attenuation coefficients and dielectric constant have been obtained for all the glasses as well as glass ceramics. The results are discussed in light of non-bridging oxygens (NBO) and heat-treatment of glasses. In addition to this, the effect of calcium and phosphorous on the infra-red spectra has been analysed thoroughly.

Korean spent nuclear fuel will reach the capacity of the available temporary storage by 2016. Pyroprocessing and direct disposal seems to be an alternative way to manage and reuse spent nuclear fuel while avoiding the wet reprocessing technology. Pyroprocessing produces several wastes streams, including metals, salts, and rare earths, which must be converted into stabilized form. A suitable form for rare earth immobilization is borosilicate glass. The borosilicate glass form exhibits excellent durability, allows a high waste loading, and is easy to process. In this work, we combined the rare earths waste of composition (in wt%) 39.2Nd{sub 2}O{sub 3}–22.7CeO{sub 2}–11.7La{sub 2}O{sub 3}–10.9PrO{sub 2}–1.3Eu{sub 2}O{sub 3}–1.3Gd{sub 2}O{sub 3}–8.1Sm{sub 2}O{sub 3}–4.8Y{sub 2}O{sub 3} with a baseline glass of composition 60.2SiO{sub 2}–16.0B{sub 2}O{sub 3}–12.6Na{sub 2}O–3.8Al{sub 2}O{sub 3}–5.7CaO–1.7ZrO{sub 2}. Crystallization in waste glasses occurs as the waste loading increases. It may produce complicate glass processing and affect the product quality. To study crystal formation, we initially made glasses containing 5%, 10% and 15% of La{sub 2}O{sub 3} and then glasses with 5%, 10% and 15% of the complete rare earth mix. Samples were heat-treated for 24 hours at temperatures 800°C to 1150°C in 50°C increments. Quenched samples were analyzed using an optical microscope, scanningmore » electron microscope with energy dispersive spectroscopy, and x-ray diffraction. Stillwellite (LaBSiO{sub 5}) and oxyapatite (Ca{sub 2}La{sub 8}Si{sub 6}O{sub 26}) were found in glasses containing La{sub 2}O{sub 3}, while oxyapatite (Ca{sub 2}La{sub 8}Si{sub 6}O{sub 26} and NaNd{sub 9}Si{sub 6}O{sub 26}) precipitated in glasses with additions of mixed rare earths. The liquidus temperature (T{sub L}) of the glasses containing 5%, 10% and 15% La{sub 2}O{sub 3} were 800°C, 959°C and 986°C, respectively; while T{sub L} was 825°C, 1059°C and 1267°C for glasses with 5%, 10% and 15% addition of mixed rare earth oxides. The component coefficients T{sub B2O3}, T{sub SiO2}, T{sub CaO}, and T{sub RE2O3} were also evaluated using a recently published study.« less

Aluminized and thermally oxidized Ni-Cr-Fe based superalloy 690 substrates with Al2O3 layer on top have been exposed in nitrate based environment (simulated high level nuclear liquid waste) at 373 K for 216 hours and sodium borosilicate melt at 1248 K for 192 hours. The surfaces of exposed samples have been characterized by using Electron probe micro-analyzer (EPMA). Elemental X-ray mapping on coated specimen that exposed in simulated nuclear waste solution revealed that the surface is enriched with Ni, Cr and Al. X-ray mapping on surface of the specimen that interacted with sodium borosilicate melt indicated that the surface is composed of Al, Fe, Ni and Cr.Aluminized and thermally oxidized Ni-Cr-Fe based superalloy 690 substrates with Al2O3 layer on top have been exposed in nitrate based environment (simulated high level nuclear liquid waste) at 373 K for 216 hours and sodium borosilicate melt at 1248 K for 192 hours. The surfaces of exposed samples have been characterized by using Electron probe micro-analyzer (EPMA). Elemental X-ray mapping on coated specimen that exposed in simulated nuclear waste solution revealed that the surface is enriched with Ni, Cr and Al. X-ray mapping on surface of the specimen that interacted with sodium borosilicate melt indicated that the surface is composed of Al, Fe, Ni and Cr.

An experimental investigation of evaporation of sessile droplets is presented on nano-porous alumina surfaces with different pore distribution morphologies and pore sizes. Evaporation can be considered as a quasi-steady-state process, such that the vapor concentration distribution above the droplet satisfies the Laplace equation, but with a timevarying droplet surface. For benchmarking, the evaporation of sessile water and ethanol droplets is also investigated on standard borosilicate glass and Teflon surfaces respectively, and results are compared with the previous work. Contact angle variation with time is also recorded and high speed videos showing the spreading process of droplets on nanoporous surfaces are taken. The results clearly show that nano-structuring is an effective tool to control wettability as well as the diffusive evaporation process.

SiCf/SiBOC Ceramic Matrix Composites (CMCs) were fabricated using polyborosiloxane as the matrix resin and Nicalon™ NL-202 silicon carbide fiber as the reinforcement via polymer infiltration/impregnation and pyrolysis process (PIP). Repeated PIP cycles resulted in CMCs with a density value of ≈ 2 g/cc and a maximum average flexural strength value of 108 MPa. Oxidation resistance of SiCf/SiBOC was compared with Cf/C and Cf/SiBOC at 1000°C. SiCf/SiBOC composite shows a better oxidation resistance due to the formation of a protective layer of amorphous borosilicate glass on oxidation.

The measurement pressure of a palmtop electron probe X-ray microanalyzer (EPMA) we previously reported was reduced using stainless steel vacuum flanges for the chamber instead of a borosilicate glass tube. The improved palmtop EPMA could reach the measurement pressure of 1 Pa in 5 minutes. The time was more than twice shorter than that to reach the measurement pressure of 5 Pa with the palmtop EPMA we previously reported. Titanium, copper K lines and silver Lα line were observed during 90 seconds measurement in addition to chromium, iron, and nickel K lines when titanium, copper, and silver plates were placed on the carbon sample stage. Chromium, iron, and nickel K lines came from stainless steel, and copper K lines came from copper rod and copper plate placed on the sample stage. The improved palmtop EPMA can analyze metals except for chromium, iron, nickel, and small amount of copper in 90 seconds., "X-Ray Optics and Microanalysis"; Conference date: 5–9 September 2011; Location: Campinas, Brazil

The effect of LiCl addition on the properties of Li2O: B2O3: SiO2: TiO2 glasses has been studied. It has been observed that the ionic conductivity increases by about half an order with LiCl addition. The decrease in glass transition temperature Tg and increase in the molar volume with LiCl addition have good correlation with conductivity results. The observed increase in density of glasses has been explained on the basis of heavier Cl− ion which is accommodated in the interstices in the glass network.

Two different methods for the measurement of the thermal conductivity have been applied to a glass (borosilicate) bulk sample. The first method was in the steady-state using an arrangement of gold wires on the sample to create a thermal gradient and to measure the temperatures locally. This allows one to calculate the in-plane thermal conductivity of the sample. The same wire arrangement was also used for a 3ω-measurement of the direction-independent bulk thermal conductivity. The 3ω-approach is based on periodical heating and a frequency dependent analysis of the temperature response. The results of both methods are in good agreement with each other for this isotropic material, if thermal and radiative losses are accounted for. Our results demonstrate that especially in the case of thin-film measurements, finite element analysis has to be applied to correct for heat losses due to geometry and radiation. In this fashion, the wire positions can be optimized in order to minimize measurement errors.

We present the effect of P2O5 addition on barium calcium aluminum borosilicate BCABS glasses of composition (mol %) 35BaO‐15CaO‐5Al2O3‐(37‐x)SiO2‐8B2O3‐xP2O5 (0≤x≤5). The incorporation of P2O5 increased network polymerization and crystallization tendency. However, addition of P2O5 leads to the formation of Cr2O3 at the interface, saturating it in the ions of the metal. This improves glass‐to‐metal bonding.

We have been investigating the impact response of transparent materials during the last several years. We conducted long‐rod impact experiments into a borosilicate glass and measured penetration and rod consumption velocities as a function of impact velocity. Additional experiments have now been conducted to investigate dwell and post‐dwell response. At sufficiently low impact velocities (∼450 m/s), the glass target resists penetration, and there is dwell. If a copper buffer is placed over the glass to attenuate the impact shock and provide ramp loading, complete interface defeat can be observed for impact velocities up to 890 m/s. It was found for sustained dwell that there can be erosion of the front surface of the glass. Further, the penetration response of the glass after the dwell‐penetration transition is the same as for the experiments in which there was no dwell.

Bar impact tests, using the techniques described elsewhere in this symposium, were used to measure compressive and tensile strengths of borosilicate glass, soda lime glass, and a glass ceramic. The glass ceramic was 25% crystalline spinel, furnished by Corning Inc. There are two measures of compressive strength: the peak stress that can be transmitted in unconfined compression, and the “steady state” strength. For borosilicate glass and soda lime glass, these values were similar, being about 1.8 and 1.5 GPa, respectively. The glass ceramic (25% spinel) was almost 50% stronger. Tensile failure in the glass and glass ceramic takes places via surface flaws, and thus tensile strength is an extrinsic, as opposed to intrinsic property.

Strength of glass and glass ceramic was measured with a bar impact technique. High‐speed movies show regions of tensile and compressive failure. The borosilicate glass had a compressive strength of at least 2.2 GPa, and the glass ceramic at least 4 GPa. However, the BSG was much stronger in tension than GC. In ballistic tests, the BSG was the superior armor.

Recent results obtained regarding the failure front (FF) associated with rod penetration of borosilicate glass (BS) are reviewed. Key results are: propagation velocity of the FF, vF, decreases rapidly after impact to an approximately constant value; vF increases with rod impact velocity, vP; vF ≪shear wave velocity; vF/u≥1 and decreases with increasing vP, where u is the rod penetration velocity; vF/u appears to asymptotically approach unity with increasing vP; Taylor impact with stress state between 1D strain and stress and an impact stress in the range of the Bernoulli stress for the rod experiments, show vF(Taylor)≫vF(rod); the FF ceases to propagate a short time after the rod fully erodes and thus the stress at the rod‐glass interface goes to zero (this means the FF does not obey the classical wave equation); the cessation of the FF is abrupt, not gradual as would be expected for a diffusion phenomenon; the time delay between full rod erosion and halting of the FF is consistent with a “communication s...

Failure front (FF) and penetration velocity have been measured for long gold rods impacting and penetrating borosilicate (BS) glass. Data are obtained by visualizing simultaneously FF propagation with a high speed camera and rod penetration with flash X‐rays. Results for BS glass are qualitatively similar to those of DEDF (PbO) glass. FF velocity rapidly decreases from an initial value to a lower, approximately constant value. FF velocity increases with impact velocity, vp. The FF velocity remains significantly lower than the shear velocity, even at the highest impact velocity tested, about 2.5 km/s. The ratio of the FF velocity to the rod penetration velocity, vF/u, decreases with increasing vp and appears to be approaching vF/u = 1 asymptotically, as observed previously for DEDF glass. The separation of the FF and the tip of the rod decreases with increasing impact velocity. Importantly, since vF/u⩾1, the gold rod is always penetrating glass behind the FF.

Constitutive models for brittle materials such as glass can be very complex as they are dependent on strains, strain rates, pressures, temperatures, damage and other parameters. There may also be significant (pressure‐dependent) strength after failure such that the constitutive response is much different for intact material and failed material. A large number of laboratory tests is required to develop a comprehensive constitutive model. Another approach is to develop simple models by using penetration‐velocity data obtained from ballistic experiments. Here various functional forms of simple models (with a limited number of constants) can be used to (computationally) match the penetration velocity over a range of impact velocities. This allows for the determination of the most important parameters and it provides an approximation of the stresses that occur during penetration. This article presents several simple computational models for borosilicate glass, including single‐state models and dual‐state models (that include an intact strength and a failed strength).

In this paper, we report the experimental observations of supercontinuum generation and darkening effect in bro‐silicate glasses under 200 femtosecond pulses at wavelength of 800 nm. The spectrum of supercontinuum emission from the sample is recorded in the UV wavelength range. The length of filamentation or white light and darkening are investigated at different incident laser pulse energies. The begging position of the generated white light and darkening moves inside glass bulk with decreasing of incident pulse energy. The pulse energy threshold for supercontinuum generation and the laser‐induced darkening in this material has been measured. By controlling of the laser‐induced darkening in borosilicate glasses prepares a promising technique for designing optical devices.

The local environments around Ti, Cr, and several light rare-earth elements (La, Ce, and Nd) were investigated by in-situ XANES spectroscopy in a number of complex borosilicate glasses and melts (to 1120 C) that are used for nuclear waste storage. Examination of the high-resolution XANES spectra at the Ti K-edge shows that the average coordination of Ti changes from {approx}5 to {approx}4.5. Cr is dominantly trivalent in the melts studied. However, its average coordination is probably lower in the melt (tetrahedral ?) as revealed by the more intense Cr-K pre-edge feature. Ce also changes its average valence from dominantly +4 to +3.5 upon glass melting. These changes are reversible at T{sub g}, the glass transition temperature ({approx}500-550 C for these glasses). In contrast, the local environments of Nd, Pr, and La are unaffected by melting. Therefore, structural reorganization of these borosilicate glass/melts above T{sub g} is variable, not only in terms of valence (as for Ce) but also speciation (Ti and Cr). Both the ability of B to adopt various coordination geometries (triangular and tetrahedral) and the chemical complexity of the glass/melts explain these changes.

CdTe quantum dots embedded in borosilicate matrix are produced by two‐step heat treatment. The quantum confinement effect is observed in their optical absorption spectra. In the framework of effective mass approximation (EMA), the radius dependent oscillator strengths of the first eight allowed optical transitions (1sh‐1se, 1ph‐1pe, 1dh‐1de etc.) are found for spherical semiconductor quantum dots which are in the strong confinement limit. These oscillator strengths are employed in an optical absorption model based on density‐matrix approach. Thus, oscillator strength radius dependency is taken into account for small quantum dots in the strong confinement limit in the model. The average dot radius, its standard deviation and the number of dots in glass are determined with the help of this model from the optical absorption spectra.

The local structure around Th, U, Ce and Nd in leached silicate glasses was examined using XAFS spectroscopy at their L3 edges and also at the K edge of Fe, Co, Ni, Zr and Mo. Pellets of inactive borosilicate glasses with a simplified or a complex composition were leached statically at 90°C, at pH buffered to 0 or 6 for 28 days (surface/volume, S/V, ratios of 0.1 cm−1). These glasses are compared to another SON68 sample (denoted “SP1” in this paper) that was statically leached for 12 years under similar conditions, except for a higher S/V of 12 cm−1 and a higher unconstrained pH of 9.6. The speciation of Fe, Co, Ni, Zr and Mo in the simple and the complex unleached are similar. In the statically leached glasses, the speciation of these transition metals is mostly identical to in the unleached glasses, except in the gels formed at the surface of the glasses leached at low pH, where large speciation differences are observed. Surface precipitates, especially for Fe (as ferrihydrite), Mo (possibly sidwillite) and Th (as ThO2) were detected. Finally, the drying of the gels considerably affects the metal speciation by enhancing metal polymerization.

Symmetric Taylor and reverse ballistics tests were used in conjunction with high‐speed photography to examine the characteristics of failure in fused silica rods. Experiments were performed at impact velocities up to 800 m s−1 yielding impact pressures to approximately 7 GPa. Failure front velocities were strongly dependent on impact pressure consistent with results for borosilicate and soda‐lime glasses. One‐dimensional strain waves were observed in some experiments before a one‐dimensional stress regime was reached. For high impact pressures (> 2 GPa) the failure fronts followed almost immediately behind the incident shocks at a velocity near √ cS for fused silica, borosilicate and soda‐lime glasses.

Conventional elastic recoil detection (ERD) techniques have been employed in an attempt to elucidate the effects time, temperature and alkali ion content have on depletion layer formation during anodic bonding. Hydrogen and/or lithium ion concentration profiles were evaluated for both untreated and lithium‐treated sodium borosilicate glass. From in situ ERD, depletion layer formation is highly dependent on temperature and alkali ion content. Lithium‐treated sodium borosilicate glass improves depletion layer formation at low temperatures and at high temperatures increased ion mobility results in rapid depletion layer formation.

A fracture wave in a brittle material is a continuous fracture zone which may be associated with the damage accumulation process during the propagation of shock waves. In multidimensional structures the fracture wave may behave in an unusual way. The high‐speed photography of penetration of a borosilicate (pyrex) glass block by a hemispherical‐nosed rod (1) shows a visible flat wave forming as the fracture front. The role of the complex stress state and kinetic description of the damage accumulation are analysed to describe the process of the impact. The DYNA2D hydrocode and a kinetic strain‐rate sensitive model (2) are employed.

The aim of this work is to characterize the oxidation states and coordination behavior of Pu in glasses used for excess weapons plutonium-containing materials and waste immobilization. To this end, we studied absorption spectra of Pu in the borosilicate glass of the composition developed at Khlopin Radium Institute, as well as absorption spectra of Pu in an aluminophosphate glass (for the first time, as far as we know).

Phase zone plates for multi-kilovolt X-rays with an outermost zone width of 16.9-30 nm and aspect ratios up to 177 were generated by a sputtered-sliced technology. The generated lenses of alternating Ni80Cr20 and SiO2 consist of 188–365 layers on borosilicate glass wires and were polished by mechanical and ion processes to a thickness of 3–4 μm without carrier foil. The groove efficiency was measured at the ESRF beamline ID 21 up to 3.8% in first order. But small parts of a zone plate show an efficiency of about 10–15%.

Using concentrated natural sunlight at the NREL High Flux Solar Furnace, we have exposed several materials to acceleration factors of up to 400 times the normal outdoor UV exposure dose. This accelerated rate allows the exposure of materials such that a year of outdoor exposure can be simulated in about 5 hours. We have studied the solarization of cerium containing glass, the degradation of ethylene vinyl acetate laminated between borosilicate glass, and the yellowing of standard polystyrene test coupons. The first two candidates are of interest to the photovoltaics (PV) program, and the last candidate material is a widely used dosimeter for ultra violet (UV) exposure in accelerated weathering chambers

The hemispherical transmissivity, reflectivity, and emissivity were determined at high temperatures for various types of quartz glass and borosilicate glass. From the information, the behavior of these materials in filtering 1300 °C blackbody radiation was calculated. The results show, that depending on the glass, the losses of radiation usable for photovoltaic conversion ( 1.8 μm) maximized. In addition, high temperature optical parameters were determined for sapphire, translucent polycrystalline sapphire (TPS), and alumina. This information was used to consider these materials as substrates for selective emitters. Both sapphire and TPS have low emissivity, at high temperatures (>1000 °C), extending to >4 μm. Combining this property with the application of selective emitters, in principle, results in a more efficient emitter, limiting the generation of unusable radiation. Optical properties of erbium oxide bulk and film materials were meas...

The dielectric relaxation properties of porous glass obtained from sodium borosilicate glass were studied by Dielectric Spectroscopy in the wide frequency (20 Hz÷1 MHz) and temperature (−100 °C÷+300 °C) ranges. The relaxation process which is well marked in the temperature range: −50 °C to +150 °C and has a specific saddle-like shape was considered. A simple model has been developed in order to explain the related anomalous behavior of the relaxation time as a function of temperature. The mechanism offered is related to a kinetic transition due to the water molecule reorientation in the vicinity of a defect.

Brar and Bless pioneered the use of plate impact upon bars as a technique for investigating the 1D stress loading of glass but limited their studies to relatively modest stresses (1). We wish to extend this technique by applying VISAR and embedded stress gauge measurements to a symmetrical version of the test in which two rods impact one upon the other. Previous work in the laboratory has characterised the glass types (soda-lime and borosilicate)(2). These experiments identify the failure mechanisms from high-speed photography and the stress and particle velocity histories are interpreted in the light of these results. The differences in response of the glasses and the relation of the fracture to the failure wave in uniaxial strain are discussed.

Polycrystalline CdTe has shown great promise as a low‐cost material for thin‐film, terrestrial photovoltaic applications, with efficiencies approaching 16% achieved with close‐spaced sublimation (CSS)‐grown CdTe. Due to the inherent complexities of polycrystalline material, much of the progress in this area has occurred through a slow trial‐and‐error process. This report uses time‐resolved photoluminescence (TRPL) to characterize the CdTe material quality as a function of one basic growth parameter—substrate temperature. This characterization is done for two different glass substrate materials, soda‐lime silicate and borosilicate.

Polycrystalline thin films of CdTe grown on glass/SnO2/CdS substrates are studied using X‐ray diffraction, atomic force microscopy, and time resolved photoluminescence decay techniques. CdS films were deposited by chemical solution. CdTe films were grown by close‐spaced sublimation at substrate temperatures between 475–625 °C. CdTe thin films deposited at temperatures higher than 525 °C show preferential orientation in the 〈111〉 direction. The Grain size of the films increases with substrate temperature and the films are faceted for all the temperatures. The PL decay constant increases with substrate temperature up to 575 °C for as‐deposited films on soda‐lime substrates. Films on borosilicate substrates show an increase up to the highest temperature used (625 °C). There is systematic increase in the PL decay constant after CdCl2 heat treatment, and the range of values is 1–1.5 nsec for soda‐lime samples and 1–2 nsec for borosilicate samples.