Glass Dispersion Research Articles

Effect of Glass Fibers on Self Compacting Concrete

Self Compacting Concrete (SCC) is a specially developed concrete for concreting under extreme condition of inaccessibility from heights. It is capable to flow under influence of its own weight. It could be used when encountered with dense reinforcement and complex structural design. Problem of segregation as well as bleeding is eliminated and vibration is not required for compaction. As concrete is strong in compression and weak in tension. Hence to make it strong in tension, discontinuous Anti-Crack high dispersion glass fibers are added. SCC mix prepared with addition of discontinuous glass fibers is called as Glass Fiber reinforced Self Compacting Concrete (GFRSCC). In this paper an experimental study has been carried out to check the effect of Anti-Crack high dispersion glass fibers on the compressive strength, split tensile strength and flexural strength of SCC. The result show that, as compared to the Normal SCC, the compressive strength of GFRSCC increases by 2.80% and 12.42%, the split tensile strength of GFRSCC increases by 4.47% and 25.12% and the flexural strength of SCC increases by 6.57% and 14.34% when the Cem-FIL Anti-Crack HD glass fibers were added as 0.25% and 0.50% respectively by the weight of total cementitious material contents. The addition of 0.25% Cem-FIL Anti-Crack HD glass fibers to SCC has not much affect on the workability of Normal SCC. Whereas, addition of 0.50% Cem-FIL Anti-Crack HD glass fibers reduces the workability of SCC.

Iodine-doped Ge-As-Se glasses with high purity and low dispersion.

It is well known that, the incorporation of halide will improve the optical properties of chalcogenide glasses with a broad transparent range. Here, we investigated the optical properties and structure of Ge-As-Se-I glasses in order to disclose the role of halogen iodine in the formation of chalcogenide glassy network. It was found that, refractive index, zero dispersion wavelength and glass transition temperature Tg decrease with increasing iodine contents, while the cut-off edge (λvis) in the shorter wavelength blue-shifts apparently, and the whole transmission range is expanded widely. The glasses show good chemical stability against moisture. The zero dispersion wavelength of the glasses can be decreased to 4.32μm by iodine-doping. The evolution of Raman spectra of the glasses indicates that, there is no obvious peak of iodine in Ge-As-Se-I glasses and the dominated glassy network are still the (GeSe) heteropolar bonds.

Physical and chemical processes of volcanic rock hardening with alkaline silicates

The thermodynamic probability of reactions in volcanic rock compositions — an alkaline silicate binder, which is used to produce artificial stone (concrete) products with high physical and mechanical properties and with wide range of colors for interior and exterior wall tiling and external masonry, manufacturing of decorative architectural details, etc. are considered. Silicate and aluminosilicate rocks of volcanic origin (perlite, pumice, tuff, etc.) of various deposits of Armenia are dispersed volcanic glasses with feldspar inclusions and are characterized by a large variety of colors: white, beige, yellow, orange, violet-pink, pinkish, red, brown, black, greenish, bluish-white, etc. Dolomite hardener is introduced into the composition for manufacturing of waterproof concrete on a base of a chemical binder at low temperatures.The possibility of reactions in a mixture of volcanic rock – alkaline silicate – dolomite – water was assessed by thermodynamic method. The calculation of Gibbs energy of the interaction reactions in the indicated system witnessed the possibility of realization of hydration, hydrolysis, silicate formation reactions even at a temperature of 298K.The formation of hydrated silicates and calcium and sodium aluminosilicates, guarantees the binding properties of the composition under normal conditions. With an increase of the temperature to 375, 475, 574K, the probability of reactions increases.

Metoda obliczeniowa tribotechnicznych charakterystyk przekładni zębatych metal-polimerowych z poliamidu wzmocnionego włóknem szklanym z uwzględnieniem korekcji zębów

The paper proposes a new method for calculating the service life, wear and contact pressures of metal-polymer gear drives with a correction profile. The effects of height and angular modification in a gear drive made of dispersive glass fibre-reinforced polyamide and steel on its contact and tribocontact parameters are determined. A numerical solution obtained for the gear with height correction has shown that the life of such gear is the longest when the profile correction coefficients 1 2 x = −x = 0.1. It has been found that the service life of the gear with angular correction is shorter than that of the gear with correction height. The effects of gear tooth height and angular correction on maximum contact pressures and pinion wear are examined and determined.

Direct measurement of refractive index and dispersion of optical glass by dual-prism configuration with imaging spectrograph

We present a simple and precise method based on a dual-prism configuration combined with spectrograph for wavelength-dependent refractive index and absorption measurements in optical glass. This technique measures the angle deviation due to the refractive index difference between two prisms. The refractive indices of dense flint N-SF11 glass from 400 to 650 nm were measured, and the limitations of the system were evaluated. From our results, the three-term Sellmeier coefficients of the glass sample were calculated showing excellent agreement with standard values.

Highly conducting graphene dispersed silicon oxycarbide glasses

In this study, we discuss dense and amorphous silicon oxycarbide ceramic system with a very low sheet resistance (0.1 Ω) at room temperature. Our process incorporates graphene nanoplatelets (GNP) as a nano-filler to enhance the electrical conductivity of the ceramic system. The graphene dispersed ceramic composites have been synthesized by the polymer-to-ceramic route by incorporating GNP in the polymeric stage. Further, spark plasma sintering is carried out to densify these composites. The structure of these composites is characterized by X-ray diffraction, Raman spectroscopy, high-resolution transmission electron microscopy, and high-resolution scanning electron microscopy. Four-probe electrical conductivity measurement carried out on the pellets revealed bulk electrical conductivity as high as 13 S/cm, which is the highest value reported for the amorphous silicon oxycarbide ceramics. Our studies show that the continuous network of formation of GNP in the glassy matrix is responsible for the high electrical conductivity in these composites.

A systematic study on polymer modified alkali-activated slag – Part I: Stability analysis of colloidal polymer dispersion in sodium water glass

Colloidal stability of polymer particles in activator is the pre-condition for the application of polymer dispersion in alkali activated materials (AAM). In this study, investigation of the stability of classical cement-stable polymers (styrene acrylate (SA) and ethylene-vinyl acetate (EVA)) in the presence of sodium silicate with different moduli at varied dosages and storing times was conducted through combined techniques including laser particle analysis and ultraviolet-visible spectrophotometry (UV–Vis). It is found that SA is significantly more stable than EVA dispersions. Dosage of sodium silicate and storing time are the main factors for loss of colloidal stability of the polymer particles. The highest colloidal stability of the latexes was observed with the lowest investigated modulus (M < 1.81). Sodium sulphate alone or a combination of sodium sulphate and hydroxide ions have no effect on the colloidal stability of polymer particles. However, in the presence of sodium silicate, sodium sulphate greatly decreases the colloidal stability.

Study of soft magnetic composites of iron coated with nanoparticles dispersion in liquid glass

Abstract This work presents the study and development of soft magnetic composites of iron coated with alumina nanoparticles dispersed in sodium silicate, also known as liquid glass. It is proposed that the nanoparticles dispersion increases the thermal resistance of the glassy coating, allowing a heat treatment with higher temperatures, reducing the internal stresses generated during the pressing and reducing core losses. Thermogravimetric analysis under an oxidative atmosphere of the powder samples and Scanning electron microscopy and energy-dispersive X-ray diffraction of fractured compacted samples are shown to discuss the coating thermal behavior. Also, electrical resistivity, relative permeability and magnetic losses of samples with and without nanoparticles dispersed in sodium silicate are shown discussing their loss separation.

The unusual solidification process of alkali activated slag and its relationship with the glass structure of the slag

Two types of blast furnace slags (HS N and HS V) with different CaO/SiO2 ratios, were activated by potassium silicate solution (Ms = 1). The results showed that most of the alkali silicate activated slag AAS mortars lost their workability within 10 min. Only an AAS mortar made from slag HS V had an outstanding fluidity even after 20 min. The microstructural evolution of the AAS pastes, as well as their selective dissolution residues after 1 h, were analyzed by an ultrasonic method, TGA, FTIR and solid state 29Si/27Al NMR. By employing a model developed for aluminosilicate glasses, Si(Qn(kAl)) species in the slags were calculated and fitted to their 29Si NMR spectra. The results indicate that slag HS V experienced incongruent dissolution during hydration and that its dispersed glass structure in terms of Si(Qn(kAl)) abundance, was significant with respect to its unusual solidification process.

Compensating spatially dependent dispersion in visible light OCT.

Visible light optical coherence tomography (OCT) has recently emerged in retinal imaging, with claims of micrometer-scale axial resolution and multi-color (sub-band) imaging. Here, we show that the large dispersion of optical glass and aqueous media, together with broad optical bandwidths often used in visible light OCT, compromises both of these claims. To rectify this, we introduce the notion of spatially dependent (i.e., depth and transverse position-dependent) dispersion. We use a novel sub-band, sub-image correlation algorithm to estimate spatially dependent dispersion in our 109nm bandwidth visible light OCT mouse retinal imaging system centered at 587nm. After carefully compensating spatially dependent dispersion, we achieve delineation of fine outer retinal bands in mouse strains of varying pigmentation. Spatially dependent dispersion correction is critical for broader bandwidths and shorter visible wavelengths.

FOAMED GYPSUM MATERIALS WITH FLUORIDE ADDITIVE

Purpose: The aim of this work is to investigate compositions and operational procedures for gypsum foamed materials based on acid fluoride and define conditions for the formation of the foamed structure and ways to improve the strength of foamed samples. Materials/Methodology/Approach: A capacity of sulphuric acid to interact with calcium carbonate with release of carbon dioxide is laid for this research. The hallmark of this study is acid fluoride used as a recycled material in which the residual acid adsorbs on anhydrite grains. Also, liquid glass and aluminum oxide nanofibrer are added to the composition. In this research, standard procedures and physicochemical techniques are used for the detection of properties of constructional materials. X-ray diffraction and differential thermal analyses are carried out to study the chemical composition of acid fluoride. The production of heat-insulating material includes preliminary dosage of initial components (acid fluoride, liquid glass, stabilized dispersion of aluminum nanofiber, sodium carbonate and water); blending of these components during 1–2 min followed by the gypsum addition; hardening in chambers for 24 h at 40–60 °C; pouring the ready mixture in divided molds. Standard equipment can be used for this production process. Research findings: The additional use of liquid glass and aluminum oxide nanofiber provides high physical and mechanical properties of samples. The high strength of material is insured by hydration of gypsum and acid fluoride followed by the chemical reaction due to the hardening catalyst. Heat-insulating properties appear due to porosity of product achieved by the release of carbon dioxide and oxygen during the interaction between acid fluoride and sodium carbonate as well as by the dispersion of aluminum oxide nanofiber accompanied by pore formation. Liquid glass and aqueous dispersion of nanofiber are very important for the material composition. The hardness increase occurs due to the formation of calcium silicates of different valency and their hydrates and due to the addition of nanofiber stabilized by sodium hydroxide of aluminum oxide representing a specific proportion of aluminum oxide and AlOOH. As a result of nanoparticle-Ca ion interaction, calcium aluminates and hydrated aluminates form. Calcium silicates and aluminates form the main space frame for the structure of gypsum stone. Additionally, Na 2 SO 4 hardener forms during the interaction of the blend components, i.e. the system is capable to autocatalysis. Also, the appeared non-soluble and slightly soluble products reinforce the stone structure, such that the initial, large gas release which provides low density and pore formation, does not lead to a sharp strength decrease, thereby ensuring the sufficient quality of material. When the oxide film of aluminum fiber is damaged, its violent reaction occurs with aqueous mixture components with hydrogen release. Practical implications: The obtained results can be used in construction of low-rise building and manufacturing partitions for rooms and flats. Originality: Hydration and pore formation processes are described for hardening gypsum materials based on acid fluoride. These processes allow controlling the mixture composition and properties of binding and binding-containing constructional materials. The authors suggest dependencies for control for the composition, structure and properties of composite, heat-insulating materials. The authors show that it is possible to render a targeted effect on the structure formation observed in complex additives which assist in the production of effective walling materials.

Dispersion of Li2SO4-LiPO3 glass in LiTi2(PO4)3 matrix: Assessment of enhanced electrical transport

A novel mechanical milling assisted synthesis route has been used to prepare new generation Li+ ion glass-ceramic composites using (i) glassy system 60[Li2SO4]-40[LiPO3] (60LSLP) and (ii) Li+ NASICON, i.e., LiTi2(PO4)3 known as LTP. Effect of compositional alterations, sintering conditions and cooling process on electrical transport has been investigated. Preparation conditions along with compositional alterations have yielded in reporting the best conducting composition. The ionic glass content was varied in (60LSLP)y-(LTP)100-y matrix for y = 5–20 wt %. It has been observed that various parameters viz. milling time, composition, annealing temperature, time and cooling conditions have a significant impact on ionic transport. The highest in-grain (∼2 × 10−4 Ω−1 cm−1) and grain boundary (∼1 × 10−5 Ω−1 cm−1) Li+ ion conductivity values at 100 °C have been obtained for y = 20 wt%. These have been found to be significantly higher than that of the pristine LTP prepared with similar preparation conditions. Electrical response (Z″-ω) and dielectric relaxation (tan δ - ω) investigations suggest that mobile Li+ ions from glassy phase significantly contribute to conductivity. The elemental distribution investigations using Energy Dispersive X-ray Spectroscopy (EDS) mapping on fractured surface suggests homogeneous distribution of LTP and glassy phase in the composite. Cyclic Voltammetry (CV) results reveal no degradation in the electrochemical stability in 20 cycles, and that these composites are potential candidates for Li+ ion all-solid-state battery applications.

Unravelling interrelations between chemical composition and refractive index dispersion of infrared-transmitting chalcogenide glasses

A facile procedure for compositional screening of chalcogenide glass (CG) is proposed to manage its infrared transmission edge (ωc) as well as refractive index dispersion (ν) in the long-wavelength infrared (LWIR) range. Both ωc and ν of CG turn out to be interpretable simply in connection with its chemical composition based on a postulation that CG behaves as a single average harmonic oscillator (SAHO). In this SAHO model, ωc is expressed as a function of molar mass and average bond energy, both of which are easily accessible for a given CG composition. Two prototypical CG-forming systems in Ge-Sb-Se and Ge-Sb-S compositions exemplify the empirical compositional dependence of ωc, which further plays a decisive role in determining ν. Following the present approach, a set of highly dispersive CG compositions in the Ge-Sb-S system is newly unveiled together with low-dispersion Ge-Sb-Se glasses. It is then experimentally demonstrated that a doublet lens configuration consisting of convex and concave lenses with low and high ν values, respectively, is able to reduce the optical aberrations. This finding presents an opportunity that ν can be envisaged just based on the compositional ratio of CG, thus facilitating completion of the LWIR Abbe diagram.

Quantum manipulation of biphoton spectral distributions in a 2D frequency space toward arbitrary shaping of a biphoton wave packet.

Arbitrary shaping of optical waveform is fundamental interest from basic science to advanced optical technologies. However, it is still challenging task for shaping a biphoton wave packet. Here we experimentally manipulate the spectrum and phase of a biphoton wave packet in a two-dimensional frequency space. The spectrum is shaped by adjusting the temperature of the crystal, and the phase is controlled by tilting the dispersive glass plate. The manipulating effects are confirmed by measuring the two-photon spectral intensity (TSI) and the Hong-Ou-Mandel (HOM) interference patterns. The technique in this work paves the way for arbitrary shaping of a multi-photon wave packet in a quantum manner.

Dual effects of LiF doping on the size evolution and luminescence properties of Ag nanoclusters in borosilicate glass

In this research, the Ag nanoclusters (Ag NCs) dispersed borosilicate glasses with the absence and presence of LiF were prepared by the melt-quenching method. The absorption, photoluminescence, FTIR results indicated that the doping of LiF plays dual effects on the size evaluation of Ag species: the introduction of F− and Li+ can promote and restrain the formation of Ag NCs, respectively. It was also indicated that the promotion effect of F− is overwhelming at lower LiF doping concentration, while the restrain effect of Li+ becomes dominated when increase LiF concentration to 8 mol%. Besides, our research further proved that the formation of Ag NCs is very sensitive to the presence of F content, even the introduction of rare earth ions in the form of fluoride or oxide can obviously modify the amount and size distribution of Ag NCs and thus affect the luminescence properties of the codoped glasses.

Optimization of Sintering Time and Holding Time for 3D Printing of Fe-Based Metallic Glasses

Fe-based metallic glasses are amorphous alloys with high strength, high hardness, and excellent corrosion resistance; however, the immaturity of processing methods has prevented their wide application in industrial production. Fe-based metallic glass parts were manufactured employing pneumatic injection additive manufacturing in this study. An evenly dispersed and stable Fe-based metallic glass powder slurry with a solids content of 50% was prepared firstly. Then the Fe-based metallic glass parts were printed. The printed parts were dried, debinded, and sintered for strengthening. The deformations of the printed parts and sintered parts relative to the original model were then analyzed by a 3D scanning reconstruction method. The slightly average bulging and sunken deformation of the printed parts and sintered parts confirmed the good printing accuracy of the pneumatic injection manufacture system. The effects of the sintering temperature and holding time on the properties of the sintered parts were studied. For a sintering temperature of 580 °C and holding time of 1 h, the surface quality of the sintered parts was better. The sintering of 3D-printed Fe-based metallic glass parts was preliminarily realized in this study, and the feasibility of preparing Fe-based metallic glass using pneumatic injection additive manufacture was verified.

Fabrication and Mechanical Characterization of Glass fibre reinforced Epoxy Hybrid Composites using Fly ash/Nano clay/Zinc oxide as filler

In this work the characterization of the mechanical behaviour of glass fibre reinforced epoxy hybrid composites were carried out. With three types of fillers- Nano clay- Zinc oxide- fly ash at different weight ratios and combinations were dispersed with matrix material epoxy by ultra-sonication method. Epoxy glass composites with various fillers were fabricated by hand lay-up technique. Mechanical characterization of Glass fibre reinforced Epoxy Hybrid Composites using Fly ash/Nano clay/Zinc oxide as filler were carried out for tests for tensile, flexural and impact strength properties. Experimental analysis shows Nano clay/fly ash epoxy composites show comparatively higher tensile and impact strength. While Zinc oxide/fly ash epoxy glass composite exhibited better flexural strength. Hybrid filler material dispersed glass fibre reinforced composites can be used for structural application as properties it processes are higher as compared to plain glass fibre reinforced epoxy composites.

Understanding the oxidation behavior of a ZrB2–MoSi2 composite at ultra-high temperatures

This basic research investigates the microstructure evolution of a composite based on ZrB2-MoSi2 from the as-sintered features to the changes occurring upon oxidation at ultra-high temperatures, 1650 and 1800 °C, in a bottom-up loading furnace for 15 min. Scanning and transmission electron microscopy evidenced the formation of a matrix typified by ZrB2-cores surrounded by (Zr,Mo)B2-rims with dispersed MoSi2 particles and SiO2 glass trapped at the triple junctions. The oxidation at 1650 °C induced the migration of silica to the surface, which formed a continuous and protective scale. Below this scale, the matrix evolved into ZrO2 grains encasing MoB nano-inclusions, as a result of the oxygen and boron oxide partial pressures established in the subscales. Underneath, a MoSi2-depleted boride region, but substituted by SiO2 and MoB was found. The same phases were observed upon oxidation at 1800 °C, but a thicker and more turbulent oxidized layer formed as a consequence of the rapid evolution of MoO3, SiO and B2O3 gases from the scales beneath the outermost silica-layer.According to the observed phases and the calculated phase stability diagrams, the partial pressures gradient within the oxide layer were defined and the effect of Mo-doping in boride matrices on the oxidation behavior was compared to that of other transition metals to establish a criterion design for the realization of ceramics with improved oxidation resistance.

A modulation technique for the measurement of the DC longitudinal Faraday effect

A modulation of light technique, using a lock-in amplifier, is described and tested to investigate the longitudinal Faraday effect in isotropic media. The Faraday rotation is measured directly from the lock-in amplifier. The Verdet constant and dispersion of lead-silica SF-59 Schott glass, at room temperature of 25 °C, were determined for varying wavelengths and expressions for their wavelength dependence were determined. The Verdet constant of water is also investigated. The results compare extremely well with other studies. The technique is suited to measure very small Verdet constants and can be easily conducted in an upper-level undergraduate laboratory.

The propulsive capability of explosives heavily loaded with inert materials

The effect of inert dilution on the accelerating ability of high explosives for both grazing and normal detonations was studied. The explosives considered were: (1) neat, amine-sensitized nitromethane (NM), (2) packed beds of glass, steel, or tungsten particles saturated with amine-sensitized NM, (3) NM gelled with PMMA containing dispersed glass microballoons, (4) NM gelled with PMMA containing glass microballoons and steel particles, and (5) C-4 containing varying mass fractions of glass or steel particles. Flyer velocity was measured via photonic Doppler velocimetry, and the results were analysed using a Gurney model augmented to include the influence of the diluent. Reduction in accelerating ability with increasing dilution for the amine-sensitized NM, gelled NM, and C-4 was measured experimentally. Variation of flyer terminal velocity with the ratio of flyer mass to charge mass (M/C) was measured for both grazing and normally incident detonations in gelled NM containing 10% microballoons by mass and for steel beads saturated with amine-sensitized NM. Finally, flyer velocity was measured in grazing versus normal loading for a number of explosive admixtures. The augmented Gurney model predicted the effect of dilution on accelerating ability and the scaling of flyer velocity with M/C for mixtures containing low-density diluents. The augmented Gurney model failed to predict the scaling of flyer velocity with M/C for mixtures heavily loaded with dense diluents. In all cases, normally incident detonations propelled flyers to higher velocity than the equivalent grazing detonations because of material velocity imparted by the incident shock wave and momentum/energy transfer from the slapper used to uniformly initiate the charge.