Types Of Glass Research Articles

Composition analysis and identification of ancient glass objects based on AdaBoost and CART classification tree

Ancient glass is highly susceptible to weathering by the burial environment, and a series of chemical reactions will occur in the process, which leads to changes in the chemical composition of glass artifacts. In order to identify and classify the composition types of glass artifacts, this paper uses high potassium glass and lead-barium glass as target training models to derive CART stump (CART tree with only 2 layers) combinations as a way to analyze the classification laws. Then, we analyzed the sub-classification results of weathering, color, and ornamentation, and analyzed the classification rules according to their chemical composition, and came up with the classification method based on CART stumps. In order to identify the type of unknown types of glass, this paper uses an integrated learning algorithm model based on CART classification tree and AdaBoost to train a prediction model using all the samples, with the objective of artifact type, and then performs type prediction on the data. This study is important for the correct classification of glass types.

Exploitation of ladle furnace iron slag for semiconductor borosilicate glass production

The supply consumption of ladle furnace slag (LFS) is a prominence of recent researches and is extensively considered. In this work LFS has the potential to be utilized as the main raw material for producing glass and glass-ceramics because of its chemical compositions similarities to the silicate glass materials. Three borosilicate glass samples were produced via melting – quenching technique. The three samples contained 10, 20, 30 wt % of slag waste materials, respectively. The second sample was heat treated at 625 °C, guiding by DTA studies, for 2, 6, 10, or 15 h. XRD studies showed traces precipitation of Ca(Mg,Al) (Si,Al)2O6 (diopside), Sodium Aluminum Silicate (NaAlSiO4), Sodium Aluminum Borate (Na2Al2B2O7) and Clinoenstatite (MgSiO3) phases. FTIR analysis demonstrated the same functional groups through glass and glass ceramics sample confirming that all prepared samples had the same structure. Ferrimagnetism property of a glass sample and its glass ceramic sample derivative was confirmed by vibrating sample magnetometer (VSM) analysis. Vickers microhardness and fracture toughness results indicated noticeable rising in toughness value and decreasing of hardness after using 100 g load by increasing slag percent in glass samples. The glass ceramic sample had little change, in hardness and toughness values, rather than its corresponding glass sample due to its lower crystallization behavior. The low dielectric constant values are very good indication for the availability of using these type of glass for electronic applications. X-ray photoelectron spectroscopy (XPS) studies indicate that manganese ions are found as MnO in both glass and glass ceramic samples.

Viking Age Windows

In the last 25 years a conspicuous amount of plane glass – windowpane fragments – has surfaced on archaeological sites from the Viking Age. These finds have not received scholarly attention as they are not recognised as a genuine prehistoric (i.e. pre-1050 Scandinavia) occurrence. This paper aims to investigate a select group of archaeological localities that all have a significant amount of glass objects and fragments, and which also serve as mainstays for continental influences, commercial trade, as well as ritual activities. It offers the study of the chemical composition of these windowpane fragments, their distribution, provenience, and discusses their potential use as windows in Viking Age Scandinavia. Based on the chemical composition of the analysed plane glass (via LA-ICP-MS) the paper argues, firstly, that the glass most likely should be dated to the 9th to 11th centuries; secondly, that there are two possible import paths of raw material with one recognized at the early emporia based on east Mediterranean types of glass, and another with a continental type of glass found at the aristocratic sites. Finally, the paper argues that the windowpanes very likely could have been used in contemporary glassed windows placed in wooden buildings at these sites.

Exploring a monotonically non-decreasing behavioral function on shielding properties and transmission factors in borosilicate glasses through heavy metal oxide reinforcement

In this study, the gamma-ray attenuation properties and transmission factors of different types of glasses formed in the (B2O3)x[(ZnO)0.60-(SiO2)0.40]1-x system as a function of increasing heavy metal oxide ratio were investigated. For transmission factor and absorption coefficient calculations, the general-purpose Monte Carlo code MCNPX (2.7.0) was used. In addition, the Phy-X/PSD code is used to obtain some important gamma-ray shielding parameters. According to the obtained results, increasing the quantity of heavy metal oxide in the glass composition favorably affected the examined parameters and lowered the transmission factor and buildup factor values. Furthermore, it has been observed that parameters such as the absorption coefficient and the effective atomic number increase as a function of increasing heavy metal oxide contribution into glass configuration. The lowest half value layer values are reported for S1 sample. For example, half value layers are reported as 3.313 cm, 3.449 cm, 3.764 cm, 3.625 cm, 3.515 cm for S1, S2, S3, S4, and S5 sample at 1 MeV photon energy, respectively. According to the transmission factor values, S1 is the sample that allows the least transmission of primary photons and demonstrates the highest resistance. It was observed that the minimal exposure build-up factor and energy absorption buildup factor values for the S1 sample at 10 mean free paths. It can be concluded that the heavy metal oxide additive applied to borosilicate glasses creates a non-decreasing functional behavior effect that is monotonic in gamma-ray attenuation parameters.

Surface Tensile Strength and Hertzian Fracture Resistance of Patterned Acid-Etched Glass

Patterned acid-etched glasses are frequently used in horizontal glass surfaces that may be walked on, such as floors and staircase treads. These glasses provide useful antislip properties, but the foot traffic cause contact stresses and ageing mechanisms that are poorly understood and can affect the strength of the acid-etched glass. This study explores these strength-reducing effects by undertaking nondestructive and destructive evaluations of two acid-etched glasses with geometrically different surface patterns and comparing their mechanical performance to unetched float glass. In particular, residual surface stress, Hertzian fracture resistance, and fractographic characteristics are determined for each glass type. The surface tensile strength of the glasses is also evaluated by means of destructive flexural tests before and after artificial ageing. The flexural tests reveal that the ridge areas of the acid-etched surface patterns are more susceptible to the formation of digs and deeper surface flaws and are therefore weaker than both the valley areas of the acid-etched pattern and the surface of the unetched float glass. Correspondingly, the acid-etched glass with the highest proportion of ridges was more susceptible to ageing-induced flaws and had the lowest surface tensile strength. The contact (Hertzian) fracture resistance was also significantly affected by the presence of a surface pattern in the acid-etched glass; specifically, the lowest contact strengths were recorded for hard body contact on the ridges of the pattern. The fracture phenomena and new data presented in this paper provide useful insights on the long-term performance of etched patterned glass. The findings can provide the bases for real-world design decisions and for glass forensics.

Stability of Glass Ceramic Sealants in Atmospheres with Increased Water Contents

For Solid oxide fuel cells (SOFC), operating at temperatures above 800 °C, glass ceramic sealants are state of the art. The properties of the glass ceramics are adapted to the metallic and ceramic join partners, operation conditions, as also to the atmospheres: fuel gas and air. In SOFCs, glass ceramic sealants offer reliable, long term stable operation over several 10,000 hours of service. The demand to operate solid oxide cells (SOC) in fuel cell- as also in electrolysis cell mode increases the demands of the stability of the sealants against atmospheres. In the electrolysis mode, the SOC-stacks were impinged by gas with high water contents to produce H2. Water contents of up to 95 % and temperatures above 800 °C are hard conditions for all applied materials of SOC stacks. In addition, glass ceramic sealants have to electrical insulator under applied electric voltage. In the electrolysis mode, the applied voltage is even higher than in fuel cell mode. In conclusion, the electrolysis mode is much harsher as fuel cell mode and glass ceramic sealants have to be adapted to this. Glasses in the system BaO-CaO-Al2O3-B2O3-SiO2 with La2O3-additions have the potential to form glass ceramics with extraordinary high coefficient of thermal expansion (CTE)values, which are suitable for use as sealants compatible with Crofer 22 APU interconnect. Their characteristics have been generally described in various studies and are also in focus of our own work and have proven their suitability for use under SOFC operating conditions. However, achieving such high CTE values is especially challenging when these glasses must be designed for use in stacks operating with electrolyte supported cells because sealing and operating temperature are usually higher than in other stack designs. Their behavior under simulated electrolysis conditions together with a direct correlation of test by using these glasses as sealants in real stack designed to operate with electrolyte supported cells has not been investigated yet and presents the scope of this study.For this study, a series of glasses has been prepared as glass powders and characterized in terms of relevant thermophysical properties such as softening behavior, thermal expansion and formation of crystalline phases. La2O3-free sealing glasses established as standards for use in commercial stacks served as references and results of both groups of sealing glasses have been compared. The new La2O3-containing glasses showed CTE-values up 10.8 ppm K-1 at a glass transition temperature ranging between 640°C and 650°C for a partially crystallized microstructure. The softening and crystallization characteristics analyzed by hot stage microscopy and DSC/TGA allow sealing processes of stacks components in the temperature range between 900°C and 950°C. Helium-leakage rates of sealed sandwich type samples made of Crofer 22 APU showed values below 10-8 mbar l-1 s-1. From suitable glasses sandwich type sample sealings made of two Crofer 22 APU coupons have been prepared and exposed to a dual atmosphere in a special test rig under simulated electrolysis conditions at 850 °C with different electrical voltages applied across the sealants and a water content of 50 % in the steam atmosphere. In this out-of-stack environment, the resistance of the glass sealants can be recorded while being treated with high water atmosphere and electric voltage of up to 5 V at 850 °C. The development of resistance over 300 hours of aging show which glass composition fit to the conditions and which exhibit high degradation rates. Afterwards cross sections have been prepared and analyzed by SEM. Effects observed in the interfacial regions glass-Crofer 22 APU and glass-atmosphere have been correlated with the electrical measurements. A 30 layers stack was tested under typical SOEC conditions for approx. 3200 hours. Four different glass types were used and compared in terms of their degradation rate and the ASR value. The selection of the glasses was made according to their thermal expansion and softening behavior as well as their insulating properties.

Study of Humidity During Sand Dewatering Using a Cone-Shaped Installation

The issue of moisture content of sand, which is used in construction as an aggregate for asphalt concrete mixtures, in the production of silicate building materials, roofing roll materials, and various types of glass, is considered. The results of an experimental study of the process of dewatering construction sand samples in conical warehouses under the conditions of using vacuum systems, depending on the time and placement scheme of needle filters, are presented.

Study of the behavior of cesium and strontium in co-melting basalt and silica gel containing cesium or strontium nitrates for the development of a potential material for radioactive waste immobilization

The work studied the distribution of cesium and strontium in cast stone matrices obtained by co-melting basalt and silica gel (hereinafter SiO2) containing cesium or strontium nitrates at 1623 K during 5 h. The melt cooling rate was ∼2 °C/min.Co-melting basalt and SiO2 containing CsNO3 or Sr(NO3)2 at a basalt/SiO2 initial mass ratio of 5 : 1 produced cast stone matrices, in which the main phases were Cr–Fe spinel and glass. At the same time co-melting basalt and SiO2 containing CsNO3 or Sr(NO3)2 at an initial mass ratio of 2 : 1 yielded matrices which, apart from Cr–Fe spinel and glass, included pollucite, clinopyroxene, and Ti-containing magnetite phases for Cs-containing system, magnetite and olivine phases for Sr-containing system.For Cs-containing system at a basalt/SiO2 initial mass ratio of 5 : 1 the glass phase showed almost an even distribution of cesium, whereas the spinel phase was virtually free of cesium. At a basalt/SiO2 initial mass ratio of 2 : 1 the major amount of cesium was found in the pollucite phase, where it mainly occurred in parts containing SiO2. Some amount of cesium was found in the glass phase. The other crystal phases found in the matrix were virtually free of cesium.For Sr-containing system at a basalt/SiO2 initial mass ratio of 5 : 1 the process yielded two types of glass: one rich in Ca and the other in Sr. Strontium was mainly found in the glass phases. The spinel phase was virtually free of strontium. At a basalt/SiO2 initial mass ratio of 2 : 1 strontium was mainly found in the glass phases. The magnetite, olivine, and Cr–Fe spinel phases were virtually free of strontium.

Optimizing Energy Efficiency in High-Rise Residential Buildings in Abu Dhabi’s Hot Climate: Exploring the Potential of Double Skin Façades

This study investigates energy efficiency in high-rise residential buildings in Abu Dhabi, where the increased use of glass building façades has led to increased air-conditioning costs due to heat gain. The research focuses on evaluating the type of glass and the appropriate cavity between glass façades to minimize energy consumption while incorporating sustainability and innovative design principles. To achieve these objectives, this study employs a Double Skin Façade (DSF), a high-performance façade that adapts to the external climate conditions to fulfill internal cooling load requirements and meet occupants’ needs. Data were collected through an online survey distributed among residents of a selected residential tower, and a combination of qualitative and quantitative approaches was utilized to analyze the gathered information. The selected case study was analyzed using Energy Plus simulation software using the existing data and available details. The analysis aimed to identify the optimal DSF design that significantly enhances energy efficiency. The findings of this study emphasize the substantial impact of the optimum DSF design on energy efficiency in high-rise residential buildings. Through modeling existing data and comparing them with new model results for each variable, this study demonstrates that a DSF with a 35 cm cavity, comprising a double-glazed single skin layer in the interior and a Low-E double-glazed single skin layer as an outer layer, can reduce overall air-conditioning energy consumption by over 25%. These outcomes provide valuable insights into implementing DSF as a solution to address the unique energy challenges presented by high-rise residential buildings in hot climates.

Quantitative fractography for brittle fracture via multilayer perceptron neural network

Quantitative fractography is instrumental in the failure analysis of brittle materials, yet the methodology is currently only applied to a handful of materials and loading scenarios as the generalization of the methodology is severely hampered by the unknown roles of many physical factors. With the development of computational tools, artificial neural networks (ANNs) are widely used in engineering and could provide a reliable connection between inputs and outputs. In this work, ANN models were used to analyze the fracture strength of various glasses and ceramics fractured in both flexure and tension. A large set of data consisting of over 4,500 experimental fracture surfaces obtained from 41 types of glasses and ceramics were collected from 82 references for training the models, and the best ANN models for analyzing each scenario were selected. The trained models were further validated by experimental fracture tests conducted in this study. This study showed that the developed ANN could often outperform accepted empirical relations in the literature when predicting the fracture strength and suggested that the developed ANN could be reliably extended to estimate the fracture strength of a broader set of brittle materials. However, it was concluded that for more accurate predictions in the case of ‘non-glass’ ceramics, additional relevant physical factors should be considered in the analysis.

Early mediaeval lead glass bangles from Czermno, Poland: Results of elemental and lead isotopes analyses

AbstractThis paper presents the results from analysis of thirty 12th to 13th century glass bangles from Czermno, eastern Poland. Study of the primary glass composition was carried out by laser ablation ICP‐MS and electron probe microanalysis. Lead isotope analyses were conducted to determine the origin of the glass's main raw material. Two types of lead glass were distinguished, high‐lead glass and Slavic lead ash glass, both of which were common in Central and Eastern Europe in the early Middle Ages. Isotopic investigations show that the lead flux for the Slavic glass likely came from the Cracow–Upper Silesia region in southern Poland.

Impact of solar radiation on indoor thermal comfort near highly glazed façades in a hot-humid subtropical climate: An experimental evaluation

Solar radiation has a profound impact on indoor thermal conditions, particularly in highly glazed spaces. However, there have been limited field measurements on this subject. Focusing on subtropical climate, this study investigated the effects of irradiation on thermal comfort from two aspects, disparities in glass properties and spatial positions, through a field measurement. Six test cells, each equipped with a representative type of glass, were established; two measurement points were set at inner and near-window positions to analyze the spatial disparities and impacts of solar radiation asymmetry. PMV-PPD-based evaluation criteria were employed to assess the long-term comfort levels and classified by environmental quality index (EQI); additionally, we assessed the risk of overheating by considering two indices: overheating hours and overheating severity, which represent the duration and extent of thermal discomfort. The results indicated that radiation asymmetry varied depending on glass properties and spatial/temporal difference, leading to partial thermal discomfort. Specifically, the MRT at the near-window point increased significantly, reaching 50.8 °C for single-pane glass, 40.1 °C for single-pane tinted glass, and a minimum of 32.8 °C for double-pane reflective glass after 14:30 due to direct sunlight. In contrast, the MRT at the indoor positions remained relatively stable at around 25 °C–27 °C, irrespective of the glazing type. SHGC of glass is critical for thermal comfort, as higher SHGC values intensify the sensation of extreme warmth. Through experiments, this study quantified the relationship between thermal discomfort and glazing properties, providing valuable insights for glazing facades design that can optimize indoor thermal environments.

Study of Ancient Glass Classification and Subclassification Based on Systematic Clustering Models

Ancient glass is highly susceptible to weathering by environmental influences, resulting in changes to its internal chemical composition, which can affect the correct determination of its category. For the purpose of classifying ancient glass, three indicators of classification were chosen based on the magnitude of the mean value of each chemical composition of the two main types of glass. The ???? principle and the lower quartile principle are chosen, respectively, to determine the critical values according to whether the data follow a normal distribution or not, and the final classification results are obtained by hard voting. The hard voting model was trained with an accuracy of 97%. The two main classes of glass were then subclassed according to systematic class clustering, and by making the real data fluctuate within ±1%, the clustering was performed again under the same conditions. The same results were found as for the stable data clustering, indicating that the systematic class clustering model is stable for subclassification of each glass category.

From ultra-fast growth to avalanche growth in devitrifying glasses.

During devitrification, pre-existing crystallites grow by adding particles to their surface via a process that is either thermally activated (diffusive mode) or happens without kinetic barriers (fast crystal growth mode). It is yet unclear what factors determine the crystal growth mode and how to predict it. With simulations of repulsive hard-sphere-like (Weeks-Chandler-Andersen) glasses, we show for the first time that the same system at the same volume fraction and temperature can devitrify via both modes depending on the preparation protocol of the glass. We prepare two types of glass: conventional glass (CG) via fast quenching and uniform glass (UG) via density homogenization. First, we bring either glass into contact with a crystal (X) and find the inherent structure (CGX/UGX). During energy minimization, the crystal front grows deep into the CG interface, while the growth is minimal for UG. When thermal noise is added, this behavior is reflected in different crystallization dynamics. CGX exhibits a density drop at the crystal growth front, which correlates with enhanced dynamics at the interface and a fast growth mode. This mechanism may explain the faster crystal growth observed below the glass transition experimentally. In contrast, UGX grows via intermittent avalanche-like dynamics localized at the interface, a combination of localized mechanical defects and the exceptional mechanical stability imposed by the UG glass phase.

Compressive Split Hopkinson Pressure Bar Apparatus: Part II- Experimental Results

Investigations on high strain rate behavior of a typical unidirectional glass / epoxy composite under compressive loading are presented. Compressive Split Hopkinson Pressure Bar (SHPB) apparatus was used for the studies. Compressive properties were evaluated along longitudi- nal, transverse and thickness directions in the strain rate range of 548 - 2645 per sec. It is observed that the compressive strength is enhanced at high strain rate loading compared with those at quasi-static loading. Studies were also carried out on 10° and 45° off-axis specimens. In-plane shear strength was determined based on 10° off-axis compressive results. It is observed that the in-plane shear strength is increased at high strain rate loading compared with that at quasi-static loading. But it remains nearly constant with increasing strain rate at high strain rates.

Enzyme induced carbonate precipitation with fibers for the improvement of clay soil slopes against rainfall and surface runoff erosions

In order to improve the erosion resistance of the highway embankment slopes against rainfall and surface runoff erosions, the enzyme induced calcium carbonate precipitation (EICP) technology combined with different types of fibers, including steel, glass, and Polypropylene (PP) fibers, was studied for the treatment of the cohesive soil slope surface. The treatments were applied by a two-step method. In the first step, the treatment solutions were sprayed to the soil surface. In the second step, after the cracks were fully developed, quartz sand was filled into the cracks and another round of EICP spray treatment was applied in order to repair the cracks. Soil crack image analysis, crack repair test, rainfall and surface runoff erosion test, surface penetration resistance test, moisture content measurement, and soil microstructure analysis were carried out. The results show that the EICP technology can effectively cement the soil and improve the mechanical strength and erosion resistance of the cohesive soil slope. The average penetration resistance is about 10 times that of the untreated samples. The strength and erosion resistance of the fiber-added samples were further improved after EICP treatment with the addition of fibers. Both the glass fiber- and steel fiber-added samples exhibited excellent erosion resistance under rainfall and surface runoff erosion, with the amounts of eroded particles 35.78% and 1.89%, respectively, as compared with the sample treated with EICP only. The additions of fibers did not have any negative impact on the conversion efficiency of calcium. Meanwhile, the fibers could function together with calcium carbonate to form a net structure inside the soil so as to increase the strength and the durability, and reduce the water infiltration into soil. Therefore, the EICP treated samples with steel fibers and glass fibers have better treatment effects and are recommended for further applications.

WASTE GLASS AS AN ALKALINE ACTIVATOR AND FLY ASH AS PRECURSOR IN GEOPOLYMER CONCRETE

In this study, an alkaline activator was synthesized by dissolving waste glass in NaOH solution to explore the feasibility of using waste glass as a potential alkaline activator in the preparation of geopolymer concrete (GeoPC) with fly as precursor. A total of three types of glasses with different sizes were used. The exact concentration of Na2O and SiO2 in the activator was measured using inductively coupled plasma – optical emission spectrometry (ICP-OES). A total of 38 GeoPC mixtures were prepared using three glass types and at different Na2O and SiO2 concentration. The compressive strength of GeoPC was measured by testing specimens after 24 hours of heat curing (80±2°C) followed by 24 hours of ambient curing at room temperature (23±2°C). The compressive strength was found to depend on alumina and calcium content of glass type and moduli (SiO2/Na2O) ratio of activator. The higher liquid to solid ratio resulted in lowering of compressive strength.

Modelling and analysis of electrical performance outdoor glass insulator under various services and lightning impulse

This paper is focus on modelling of glass type insulator with voltage rating of 275 kV. The glass insulators are still widely served in overhead transmission line because of its high dielectric strength capability. However, their outdoor application has resulted in the exposure to the various service conditions such as weather, pollution and lightning conditions. Further, the inclination effect of the insulator under the nominal voltage and lightning impulse is modelling through Finite Elementary Method (FEM). Then, the model of glass insulator is constructed in three different inclination angles by using the Ansys Maxwell 3D for simulation purpose. The results show the inclined insulator due to the wind load effect has the lowest breakdown voltage at most 53.33% compared with the vertical insulator. Under the outdoor environment factors such as humid, wet and contamination, the localized electric field and current density had increased significantly. Consequently, this situation may cause the power losses, localized heating effect also reduces the electrical performance of the insulators.

Preparation of glass-ceramic-based artificial aggregates using multiple solid wastes: Crystallization mechanism

In this study, the effects of two types of waste glasses on the performance of glass-ceramic artificial aggregates (AAs) were investigated to determine the contribution of the glass in the crystallization processes and provide theoretical support for the subsequent use of the solid wastes to prepare glass-ceramic-based AAs. The results showed that introducing glass mainly provided amorphous materials to facilitate crystallization and fluxing components to reduce liquid viscosity. The crystallization mechanism of the AAs was explained by understanding the SiO2 characteristics and the liquid viscosity on the AAs properties. The results showed that amorphous SiO2 and low viscosity were beneficial to the crystallization process, and the properties of [Si–O] significantly influenced the viscosity of the liquid phase. AAs prepared with multiple solid wastes were compared with pure muck AAs, and they showed higher strength with similar densities.

A normalization method of measured elastic properties of glass NCF composites with respect to fiber volume fraction based on periodic microstructure micromechanics

International standards have requested the normalization of fiber-dominated properties in composites with respect to fiber volume fraction. However, the normalization of matrix-dominated properties has not yet been requested because there is no clear model. This partial normalization might deteriorate accuracy in design and analysis. This study developed a systematic approach for normalizing both fiber-dominated and matrix-dominated properties of composites, based on periodic microstructure micromechanics (PMM). To evaluate the accuracy of PMM, this study started from comparing the elastic properties calculated by PMM to those calculated by FEA. Then, the eight measured elastic properties were obtained by testing three different types of glass NCFs/epoxy laminates. Since PMM needs the elastic properties of raw materials, the three unknown properties among them were determined by using the back-calculation procedure developed in this study. After all, the PMM gave us highly accurate properties of the laminates, resulting in a maximum error of less than 1% when comparing the calculated elastic properties with the measured ones. Lastly, the orthotropic elastic properties of the laminates were normalized with respect to fiber volume fraction. This study makes a significant step forward in composite structures by providing a systematic approach for normalizing full elastic properties in composites.