Clear Glass Research Articles

High-transparency Clear Glass Windows with Large PV Energy Outputs

Multiple modern glass and window products based on novel glazing designs, metal-dielectric coatings, and proprietary interlayer types have been developed recently. Advanced windows of today can control properties such as thermal emissivity, heat gain, colour, and transparency. In more recent and more novel glass products, solar energy harvesting through PV integration is also featured. Typically, semitransparent and also highly-transparent PV windows are purpose-designed, to include luminescent materials, special microstructures, and customized electric circuitry. Recently, significant progress has been demonstrated in building integrated highly-transparent solar windows (VLT up to 70%, with Pmax ~ 30-33 Wp/m2, eg Clearvue PV Solar Windows); these are expected to add momentum towards the development of smart cities. These Clearvue window systems are, at present in 2021, the only type of high-transparency and clear construction materials capable of providing significant energy savings in buildings, simultaneously with renewable energy generation. The technology has already been deployed and tested in both commercial property applications and in R&D greenhousing. Of special interest is the combination of properties provided by Clearvue solar window products, which includes significant power conversion efficiency (~3.3%), which is achieved in windows of colour rendering index of 99%, simultaneously featuring high PV Yield in multi-oriented building-integrated PV (BIPV) installations.

Major to trace element imaging and analysis of iron age glasses using stage scanning in the analytical dual beam microscope (tandem)

Dark and clear silicate glasses formed during an iron age vitrification event ≈ 1500 years ago at the Broborg hillfort near Uppsala, Sweden have been analyzed using a scanning electron microscope equipped with a micro-X-ray fluorescence (μXRF) spectrometer. Correlated µXRF and electron beam-induced energy dispersive spectrometry (EDS) X-ray maps were collected via stage-scanning at constant velocity. This coupled procedure represents a new approach for the cultural heritage community to conduct analytical studies of archaeometric specimens composed of metal, ceramic, or mixed inorganic/organic materials, where major and trace element compositions are registered in space for areas up to the centimeter-length scale at micrometer-scale resolution. Overview images were used to select areas for EDS beam scan maps correlated with multispectral cathodoluminescence (CL) imaging and co-located quantitative EDS and μXRF point analysis. Fe, Ca, Mg, Ti, P, Mn, Zr, Zn, and Y are enriched in the dark glass, while Si, Al, K, Na, Ba, Sr, Rb, and Ga are enriched in the clear glass. Unmelted material is comprised predominately of quartz (SiO2) along with trace apatite (Ca5(PO4)3[Cl,OH]) and zircon (ZrSiO4). Multivariate statistical analysis was used to measure the area fractions of high variance components while lower variance components represented phase mixtures. Differences between calculated melt viscosities for the glass compositions are consistent with field and laboratory observations. Coupled large area EDS and μXRF imaging shows significant promise for informed selection of higher spatial resolution and higher sensitivity follow-up studies, e.g., those performed using synchrotron analysis.Graphical

UV coated acrylics as a substitute for generic glazing in buildings of Indian climatic conditions: Prospective for energy savings, CO2 abatement, and visual acceptability

The generic clear glass used in the existing buildings has the limitations such as high heat gain/loss, glare, and poor thermal performance. Substitution for the existing building conventional glazing systems should be given full consideration in sustainable development due to its significant impact on energy consumption and greenhouse gas (GHG) emissions. The study explores various UV-coated acrylics as a substitute for generic clear glass. Thermo-optical characterization was performed to calculate UV-coated acrylics' un-steady state thermal transmittance and solar-optical properties. A thermo-economic analysis of UV-coated acrylics was undertaken in a four-floor high glazed building in two different Indian climates (hot and temperate) to assess the reductions in heat gains, corresponding energy savings, and carbon emission mitigations. The findings revealed that UV-coated acrylics' heat gain/loss inside the buildings was reduced compared to the generic clear glass. Compared to generic clear glass, UV-coated acrylics reduced heat gain by 25.5% and 23.5% in hot and temperate climes, respectively. Reduced heat gains resulted in energy savings for cooling and heating requirements, resulting in annual cost savings of 8667 $/year for a temperate climate and 5974 $/year for a hot climate, respectively. Lower energy requirements for cooling and heating resulted in carbon reductions of 88.7 and 56.2 tCO2/year for temperate and hot climates, respectively. Energy Plus simulations have been used to validate the mathematical model results and evaluate daylight infiltration in buildings with UV-coated acrylics at various brightness levels. UV-coated acrylics' measured daylight ingress metrics and color rendering metrics ensure good visual acceptability in building interiors.

STUDY OF THE THERMAL AND ENERGY PERFORMANCE OF A TRANSLUCENT AEROGEL GLAZING SYSTEM

ABSTRACT Aerogel is an innovative superinsulating material with extremely low thermal conductivity. Currently the cost of aerogel insulation is much higher than the cost of conventional insulation materials, which hinders their widespread application in buildings. In this research, an economical translucent aerogel glazing unit consisting of two clear boundary glass panes and a composite aerogel interlayer was developed, and its thermal and energy performance was studied numerically and experimentally. The results demonstrate that a translucent aerogel glazing with a 8 mm thick composite aerogel interlayer can perform better than a high performance double pane glazing, a typical double pane glazing and the corresponding opal glazing for heating load reduction under a shaded condition, but can only notably outperform an opal glazing for improving building energy performance in heating dominated climate zones, and in the heating period. It also reveals that applying the translucent aerogel glazing is a viable energy efficiency measure mainly for shaded glazing areas, or the glazing areas requiring solar radiation control to prevent sunlight glare. The outcome of this research can give engineers and architects a whole picture about translucent aerogel glazing, especially about the appropriate means of incorporating them into a low energy building.

PRODUCTION OF SELECTED PACKAGING IN POLAND

This paper discusses the latest data on the production of selected paper and paperboard, plastic, glass, wood and metal packaging. During the study period 2016-2020/2021, there was an increase in the production of selected paper and paperboard packaging compared to 2016. There has been an increase in the production of paper sacks and bags, cartons made of paper or paperboard other than corrugated and cartons made of paper or paperboard. Among plastic packaging, the production of plastic bags and sacks played a significant role and has been growing steadily since 2016. The production of glass packaging (clear glass bottles with a capacity of less than 2.5 liters for beverages and food) increased between 2016 and 2021. Flat pallets were the dominant product among wood packaging in 2020. The decline in box pallet production was significant not only relative to 2019, but also relative to 2016. In the group of metal packaging with a capacity not exceeding 300 liters, the highest production was recorded for barrels and similar containers for any material (excluding gas), made of aluminium. It reached 93228 tonnes in 2020 and was 2.4% higher than in 2019. The packaging market in Poland and worldwide has been gradually increasing its value over the past years. The production of packaging in Poland in the coming years should grow dynamically, although not as fast as before. Undoubtedly, today the biggest challenge for the packaging industry is the rising prices of raw materials, which can negatively affect the profitability and liquidity situation of manufacturers. In particular, the prices of plastics have gone up considerably, but the costs of pulp, metals, wood and glass are also increasing, so the raw material pressure is now affecting the entire packaging industry.

Numerical evaluation of an optically switchable photovoltaic glazing system for passive daylighting control and energy-efficient building design

Adaptive control of solar heat gain and visible light transmission through windows is perceived to be a potential measure for enhancing energy conservation and visual comfort in buildings. In this study, a novel versatile window, named Building Integrated Photovoltaic (BIPV) smart window, was proposed to offer simultaneous improvement of daylighting control, on-site electricity generation and building energy efficiency, compared to traditional BIPV windows with static optical properties. The key components of the proposed system include an optically switchable thermotropic layer made of Hydroxypropyl Cellulose (HPC) hydrogel, crystalline-silicon photovoltaic cells, clear glass and low-emissivity (low-e) glass covers. The thermotropic layer can respond to heat by autonomously changing its visible and near-infrared optical properties, with which the amount of solar radiation into building spaces can be manipulated and thus the risks of excessive solar heating and illumination can be prevented. Apart from excellent solar modulation, the BIPV smart window can collect a proportion of the light scattered from the thermotropic layer and concentrate it onto the integrated PV cells for extra electricity generation. An innovative methodology has been proposed to predict the optical, thermal and electrical properties of the BIPV smart window under varying ambient conditions. Numerical simulations have been carried out in EnergyPlus to predict the window's performance when it is applied to an office-type environment in the climate of Nottingham, the UK. The influence of different window design scenarios, in terms of Window-to-Wall Ratio (WWR), orientation and transition temperature, has been investigated. It was found that using the BIPV smart window can achieve an annual energy saving of 36.6% but also a more comfortable indoor luminous environment, compared to the counterpart BIPV window (with no thermotropic layer integrated), when installed in the south-oriented office with a WWR of 25%.

Sensitive optical thin film sensor based on incorporation of 2-(2′-hydroxynaphthylazo)-benzothiazole in a sol–gel matrix for detection of manganese(II) in environmental samples

A novel selective and precise optical thin film sensor reliant on the incorporation of synthesized 2-(2′-hydroxynaphthylazo)-benzothiazole (HNABT) as a selective ionophore into the nonporous of a clear glass like material via the sol–gel process is examined for its ability to assess Mn(II) ions in aqueous solutions. The sensor was constructed by spin-coating prepared sol onto a glass plate and the influence of sonication time on immobilization of HNABT into silica matrix was demonstrated through calculation of leaching percentage. The results designated that a sonication time of 25 min is the optimum to accomplish more stable thin films without fluctuation in sensitivity and response time of the introduced sensor for a wide period. The offered sensor can be employed to evaluate Mn(II) ions within the range of 6.0 × 10−8 – 1.5 × 10−5 M with detection and quantification limits of 1.7 × 10−8 and 5.5 × 10−8 M, respectively. The relative standard deviation of 2.1 and 0.83% for reproducibility and repeatability, are assessed, along with a rapid response time of ≈3.0 min. The constructed optode is stable in wet circumstances and should be kept for at least four weeks without detecting any variation in its sensitivity. The recommended sensor was successfully performed to estimate Mn(II) in food, saline effluents, tea leaves, biological and water samples, and the results were established by the GFAAS method.

De-evolving human eyes: The effect of eye camouflage on human attention

Eyes are communicative. But what happens when eyes are camouflaged? In the present study, while either wearing sunglasses (that camouflaged the eyes) or clear glasses, participants were presented with sexually provocative and neutral images, which they viewed in the presence of another person who they knew was observing their eyes. Unbeknownst to the participants, however, we also surreptitiously monitored and recorded their eye gaze in both conditions. People spontaneously looked more and for longer at the sexually provocative images when their eyes were camouflaged by sunglasses. This finding provides convergent evidence for the proposal that covert attention operates in service of overt social attention, and suggests that decoupling overt and covert attention is much more prevalent than previously assumed. In doing so it also sheds light on the relation between the evolution of human eye morphology and systems of attention.

Effect of different building façade systems on thermal comfort and urban heat island phenomenon: An experimental analysis

This study experimentally investigates the effect of different façades systems on thermal comfort and urban heat island (UHI) phenomenon by using experimental tools. Outdoor field measurements are conducted for brick, concrete, low-E glass, aluminium composite panel (ACP), and clear glass to observe the effect of morning solar exposure on the east-west façade surface temperatures. Two different types of insulation materials, namely newspaper and corn husk mat, are also manufactured and considered. Then, laboratory experiments are performed with 1 m × 1 m panel under two 1000 W halogen lamps by measuring air, surface and material temperatures using a thermocouples data-logger with a recording interval of 5 min and IR thermovision for visual confirming. The lamps simulate solar exposure during morning (8.00 a.m.–12.00 p.m.). It is noted that the brick wall stores heat during solar exposure, and then emits that heat to indoor and outdoor environments. Additional ACP to the brick wall reduces indoor air temperature significantly whereas direct impact on the outdoor temperature should also be accounted to avoid UHI. Besides, insulation material is found to be only beneficial during heating period in terms of reducing the indoor air temperature, however it slightly incremented the outdoor air temperature. This study shows how different façade systems of buildings significantly affect both the indoor and outdoor environments. It is revealed that, in the design process, the indoor air temperature should be considered for thermal comfort while the outdoor air temperature should be considered for UHI phenomenon.

Effects of sucrose, carnosine, and their mixture on the glass transition behavior and storage stability of freeze-dried lactic acid bacteria at various water activities

Effects of sucrose, carnosine, and their mixture on the glass transition behavior and storage stability of freeze-dried Lactobacillus reuteri at various water activities (aw) were investigated. At aw = 0.328, the control (non-additive sample) showed viable cells as uncountable after storage at 25 °C for 4 weeks. The sucrose and sucrose-carnosine samples showed clear glass transition at a slightly lower temperature than the storage temperature, and maintained a large number of viable cells after storage. The carnosine sample crystalized during the storage, and a large reduction in viable cells was observed. At aw = 0.576, the samples showed a small endothermic shift due to glass transition, suggesting partial crystallization. The Tg decreased with increase in aw because of the water plasticizing effect. After storage, the sucrose-carnosine sample showed much higher viable cell numbers than the other samples. At aw = 0.753, the sucrose and sucrose-carnosine samples showed clear glass transition. The carnosine sample showed freeze-concentrated glass transition and subsequent ice melting. After storage, the sucrose and carnosine samples showed an uncountable and a low number of viable cells, respectively, but sucrose-carnosine maintained relatively high viable cell numbers. In addition, carnosine strongly supported the stabilizing effect of sucrose (even at low additive levels) depending on the aw. These results suggest that sucrose-carnosine shows a synergistic stabilizing effect.

Chest X-Ray Results in Covid-19 Positive Individuals Diagnosed at the Corona Center Using the British Society of Thoracic Imaging CXR Arrangement

Aim: To assess Chest X-ray results in COVID-19 positive individuals diagnosed at the Corona Percolation Center, Mayo Hospital, Lahore, using the British Society of Thoracic Imaging CXR classification. Methods: Altogether RT-PCR COVID-19 positive individuals tested at the Corona Percolation Epicenter, Mayo Hospital, Lahore between June 25th, 2020 and May 20th, 2021 included in this research. The cohort's mean age with age range was computed. The present symptoms and co-morbidities have been examined and tallied in rapports of facts and percentages. The outcomes of portable CXRs were categorized using the BSTI categorization and described in terms of numbers and percentages. Results: The participants' average age remained 46 years. Cough (69%) was the most common symptom, followed by fever (20%), difficulty breathing (42%), sore throat (6%), and loss of flavor and aroma (6%). (18 percent). The most common co-morbidity included hypertension (six) (22 percent). 3 participants (8%) had normal CXRs, whereas eight (25%) showed characteristic COVID CXRs. There were 23 (73%) ambiguous individuals, with just one (4%) having solitary long illness. Five (14% of individuals) had widespread lung disease, whereas 20 (64%) had detection of lung participation. The majority of 21 individuals (65%) had bilateral middle and lower zonal lesions. Conclusion: COVID-19 CXRs in this investigation showed a range of opacities from pure clear glass to mixed grounds glass opacification to accumulation in the contralateral peripheral intermediate and reduced lung zones. In these cases, the BSTI CXR writing categorization of Corona is legitimate, with both the inclusion of central zonal participation in conventional COVID-19 requirements rather than actually lower zone engagement. Keywords: Chest X-ray results in COVID-19 positive, diagnosed, Mayo Hospital, Lahore.

Epoxy resins and composites from epoxidized linseed oil copolymers with cyclohexene oxide

New materials were made by copolymerization of epoxidized linseed oil (ELO) and cyclohexene oxide (CHO) catalyzed by tris(pentafluorophenyl)borane (BCF). Pure polymerized ELO and polymerized CHO were prepared to study reactivity and properties of starting components in the presence of the selected catalyst. The catalyst furnished high conversion of CHO at a very high rate. Properties of epoxy resins are improved by increasing the amount of CHO. The copolymerization in bulk is fast at room temperature with increasing CHO content, turning violent even at low catalyst loadings, hence, the amount of CHO is limited to about 10% to allow for manageable pot life and heat management. Post-curing is required for improving mechanical properties. The materials are hard, transparent, clear glasses, with glass transitions around 45 °C. Tensile strengths of 27 MPa and flexural moduli over 1 GPa were observed. The feasibility of using these highly hydrophobic triglyceride-based epoxy resins in glass-reinforced composites and foams was demonstrated successfully. Potential applications for these novel systems are in optical materials, potting, encapsulating, and casting resins, foams and as matrix resins in composites. The preparation involves a simple mixing process and an inexpensive epoxidized vegetable oil.

Performance of a heat pipe solar collector with evacuated polycarbonate front cover

In this research, the effect of vacuum on the thermal efficiency of a heat pipe solar collector is investigated. A comparative study of solar energy loss through different transparent covering materials, including different thicknesses of clear Polycarbonate (PC) and glass sheets, is performed to choose the best covering material. The results of solar energy loss tests show that for a 4mm, and 6mm thickness covering materials, transparent PC sheets have 11% and 22% less solar energy loss respectively than glass sheets. Three cases of flat heat pipe solar collector with different covering designs that are: no cover, non-vacuumed, and vacuumed double layer PC sheets are tested. Results show that the combination of a 4mm high transmittance PC cover with vacuumed spacing results in an overall collector thermal efficiency of about 70% in comparison with only 57% for non-vacuumed double layer PC cover.

Effect of transparent glass cover material on double slope solar still productivity

Solar water distillation apparatus has been developed for the Thoothukudi coastal people in Tamilnadu, India, where drinking water is rare. This analysis focused on the possibility of employing stretched transparency PVC cover instead of usual clear glass sheet for solar distillation equipment. To increase the evaporative surface area, black cotton cloths with enlarged fibres were placed on the bottoms of stills. When the angle of inclination (13°) was equivalent to that of a glass sheet-covered still, more distilled water was recovered from the clear PVC sheet covered still. The solar still's collector received less sunlight than it might have because of an accumulation of water droplets sticking to the PVC lid. A plastic sheet material with reduced water surface adhesion is the ideal choice, or an anti-water surface adhesion chemical should be sought. Until this is achievable, the preferable cover material will remain traditional glass-covered solar distillation machines.

Energy Savings and Carbon Emission Mitigation Prospective of Building’s Glazing Variety, Window-to-Wall Ratio and Wall Thickness

Strategic selection of glazing, its window-to-wall ratio, and wall thickness of building reduce the energy consumption in the built environment. This paper presents the experimental results of solar optical properties of five glasses: clear, tinted bronze, tinted green, bronze reflective, and polymer dispersed liquid crystal glasses. Laterite room models were modeled with four different thicknesses and four different glasses using Design Builder, and thermal simulation tests were carried out using Energy Plus. The energy savings and carbon emission mitigation prospective of a building’s glazing variety, window-to-wall ratio (WWR), and wall thickness were investigated. The results revealed that among the five window glasses studied, the polymer dispersed liquid crystal glazing window (PDLCGW) was found to be the most energy-efficient for low heat gain in laterite rooms. The laterite room with 0.23 m wall thickness and 40% PDLCGW WWR reduced 18.9% heat gain in comparison with the laterite room with 0.23 m wall thickness and 40% clear glass WWR. The laterite room of 0.23 m wall thickness with PDLCGW glazing of 40% WWR enhanced cooling cost savings up to USD 31.9 compared to the laterite room of 0.08 m wall thickness with 40% PDLCGW. The laterite room of 0.23 m wall thickness with PDLCGW glazing of 40% WWR also showed improved carbon mitigation of 516 kg of CO2/year compared to the 0.23 m wall thickness laterite room of 40% WWR with clear glass glazing. The results also showed that the laterite room with 0.23 m wall thickness and 100% clear glass WWR increased heat gain by 28.2% in comparison with the laterite room with 0.23 m wall thickness and 20% clear glass WWR. The results of this article are essential for the strategic design of buildings for energy saving and emission reduction.

Novel chip-based isoelectric focusing device for fractionation of bacteria prior to their mass spectrometry identification

We have developed a planar chip utilizing divergent geometry of separation channel capable of vertical free-flow electrophoresis of particles at flows of lower hundreds of microliters per minute. The divergent flow isoelectric focusing (DF-IEF) chip consists of two sheets of clear polystyrene glass which serve as a base with working channels and a top cover sealing the separation channel. Optimization showed that the chip is capable to form pH gradient within 1 h and separation is completed in 5 or more minutes depending on the sample volume. The vertical position of the chip enabled analysis of sedimenting particles including microorganisms. Four different common bacteria species inactivated with H2O2 vapors were analyzed in a series of experiments. Isoelectric points were determined with capillary isoelectric focusing with following fractionation using DF-IEF with intact cell matrix-assisted laser desorption/ionization mass spectrometry detection. The DF-IEF chip fractionation proved promising for bacterial sample preparation from complex matrices for subsequent identification of whole cells by mass spectrometry.

Radiation Dose Assessment of the Fog Lead Acrylic Shields during Coronary Angiography: A Phantom Study

This study aimed to evaluate the effects of fogging on the effectiveness of a lead glass shield in protecting an operator from radiation exposure during conventional coronary angiography (CAG). Optically stimulated luminescence dosimeters (OSLDs) were used to measure the effects of fogged lead glass shields (FLSs) and clear lead glass shields (CLSs) on the radiation doses of a cardiac catheterization surgeon. We simulated the scatter radiation incident on the operator with five angiographic projections with 10-s exposures. Experiments were conducted with a field of view of 25 cm, maximum of 100 cm between the X-ray tube and image intensifier, and 80 cm between the image intensifier and operator. Lead glass fogging had no significant effect at any angiographic projection. The average dose at the lens of the eye, thyroid glands, and gonads did not differ significantly between FLS and CLS. Although most surgeons view ceiling-suspended shields as hindrances during surgical procedures, the radiation dose at the operator’s eyes and thyroid glands increased by 13 and 10 times without the shield. The fogging of the shield is probably caused by post-surgery UV decontamination or detergents. An operator has no cause for concern regarding the radiation protection afforded by an FLS during CAG procedures.

Energy and daylighting performance of building integrated spirooxazine photochromic films

The study of chromogenic materials and systems is particularly promising for innovative, transparent building envelopes, with thermo-optical properties adaptable to surrounding environmental conditions. This work spots light on the multiple effects of photochromic glazing on the energy consumption of buildings and on the impact that such technologies would have on the visual comfort of occupants. To our knowledge, this is the first work dealing with building integration of spirooxazine-based photochromic films. This experimental and theoretical work aims helping to fill this gap by reporting the results of a study concerning the spirooxazine photochromic molecules, integrated in transparent matrices of polymethylmethacrylate. This work discloses the potential of specific photochromic materials, especially as a function of spectral peculiarities. The figures of merit of this technology have been studied by assuming its integration in an ideal multi-storey office building, and by studying the effects in terms of energy consumption and visual comfort and proposing a comparison with several static commercial glazing technologies. The photochromic glazing demonstrated to offer significant reduction of energy use for cooling, compared to a clear glass (with yearly saving of 4079 kWh, on the Southern facade), and for artificial lighting (with a saving of 3711 kWh), if compared to the commercial solar control glazing. Furthermore, the dynamic behaviour of the photochromic glazing represented the best choice in terms of visual comfort.

Evaluation of Numidian quartz sandstones from Southern Italy for industrial applications

Numidian quartz-rich sandstones collected from four different reconstructed sections along the Apennine chain of Southern Italy, have been studied for their textural, petrographic and geochemical characteristics to verify their potential industrial use. Sampling was carried out along a NW-SE transect: Monteverde and Aquilonia sections at NW (Campania Region) and Valsinni and Rotondella ones at SE (Lucania Region). The sandstones from NW successions are subarkoses with subordinate sublitharenites. High compositional maturity is shown by these sandstones containing high SiO2 values (93wt% in average) and lowest amounts of CaO (0.08 wt%), MgO (0.1wt%), Fe2O3 (0.9 wt%) due to the absence of carbonate components (cement and lithics) and scarce presence of clay-ferruginous cement. The sandstones from SE successions show lower contents of SiO2 (87 wt% in average) and relatively higher contents of CaO (up to 7.4 wt%), MgO (up to 1.9 wt%) and Fe2O3 (up to 4.6 wt%) as compared to the previous ones, connected to the presence of calcite and clay-ferruginous cements; these can be classified as Fe-sands with subordinate sublitharenites. The sandstones from NW area show a better potential vocation to be used in the glass industry. However, the coloring elements contents are too high for clear or optical glass production. They are it is suitable as raw material for colored glass, insulating fibres, foundry molds or air Crete. With the aim of assessing the possible improvement of chemical characters, four granulometric fractions (A< 63 μm, B 63-125 μm, C 125-250 μm and D >250μm) were analyzed considering four samples from NW successions. Based on chemical composition, C and D fractions from Aquilonia area, are the most suitable for a coloured glass, while fractions A (<63 μm) and B (63-125 μm) mixed in proportions of 40 % (A) and 60 % (B), appropriately cleaned of clays, heavy minerals and iron hydroxides, could be used as raw material for the paint industry. The obtained results suggest a complete exploitation of this type of sandstones in the manufacturing industry, reducing waste materials and enhancing the economic value of these resources from southern regions of Italy.

Determination of the Firing Temperature and Optimum Ratio of Valorizing Rice Husk Ash, Clear Glass Cullet and Ranong Clay for Developing Ecological Wall Tiles

The purposes of this study were to investigate the effect of firing temperature and utilizing residue materials on the physical properties and microstructure of the ecological wall tiles. Rice husk ash (RHA), clear glass cullet (CGC), and Ranong clay (RNC) were utilized. Eleven formulations were constructed and divided into two groups with different contents of RHA, at 10% and 20%. After molding by uniaxial pressing at 10 MPa, the tested specimens were fired at temperatures of 950 and 1050ºC, with heating rate of 100ºC/h, and soaked for 1 h. The bending strength of specimens fired at 1050ºC were enhanced by up to 205% compared with specimens fired at 950ºC. Formula B1, fired at 1050oC was optimal for further commercial production. It utilized 20 wt% RHA, 50 wt% CGC, and 30 wt% RNC which met the criteria of the Thai Industrial Standard (TIS) 2508-2555 type BIII. Moreover, the microstructure of specimens was characterized by scanning electron microscopy (SEM). It revealed that a glassy phase had developed in the high bending strength specimens under the influence of high firing temperature and CGC content. In addition, RHA residue material promoted a greyish color in ceramic bodies. Finally, it can be concluded that the valorization of RHA, CGC, and RNC in the development of ecological wall tiles with white-greyish texture was feasible.