In float glass production, the homogeneity of molten glass significantly influences the product quality. Usually, stirrers are used to diminish the inhomogeneity of molten glass. In this study, the vertical stirring process in a float glass furnace was simulated and analysed using the ANSYS Fluent 14·0 software. The particle track method was used to qualitatively describe the stirring effect. The stretch rate was used to quantitatively evaluate the stirring effect. The influence of stirring on the waist backward flow was studied. The relationship between the stirrer insertion depth and the optimal rotational speed was obtained. The particles presented an S-shaped distribution after stirring. The rotation effect of the stirrer can bring the backward flow upward into the forward flow at a high rotational speed. The optimal rotational speed decreased with the insertion depth of the stirrer and presented a linear relationship. The physical simulation method was used to verify the correctness of the particle tracks obtained in the numerical simulation.

To the vast majority of those with a casual interest in art, the primary perspective can often be one which sees aesthetic concerns driving artistic production. Questions of form, composition and style can very often take precedence over more mundane ones about techniques, processes, and materials. If we wish to gain a more comprehensive appreciation of the aesthetic values of a work of art, it is perhaps helpful to begin by looking at the commercial concerns and motivations of the creators of that art. Rembrandt was just as concerned with paying off his debts as he was with creating great art. Da Vinci would probably have produced many more fascinating drawings and designs, but even fewer paintings, if he had been free from financial constraints. It is interesting therefore to consider the artistic techniques used for stained glass windows of the latter half of the 19th century in the context of the commercial realities and technological choices facing their producers. This enquiry is not only of academic interest – it is of vital practical importance to the professional conservator of stained glass, faced with the need to restore and repair our stained glass heritage.

Fine particles of glass cullet (fines) arising during glass recycling cannot presently be recycled into glass manufacture due to the potential for bubble formation and foaming. Consolidation of glass fines into briquettes could enable their re-introduction into furnaces, reducing waste and glass melting energies. Properties of briquetted cullet fines and briquette melting behaviour in soda–lime–silica glass batches are presented. Morphology and density of glass fines and briquettes; and briquette mass and mechanical properties as functions of time after formation were analyzed. Compressive strength increases linearly with time after briquette formation. With slight batch modifications to maintain the same final glass composition, up to 15 wt% briquettes were successfully added to a representative container glass batch and melted. Results confirm that briquette batch additions can provide equivalent final glass composition, optical absorption characteristics and redox to briquette-free batches, supporting their industrial uptake.

The efficiency of heat transfer through glass batch is an important factor affecting the energy efficiency of glass manufacturing and product quality. In this study, we investigated the effective thermal diffusivity and heat flux through a batch blanket of powder raw materials and briquettes, by using a large scale top heated laboratory furnace. Particular focus was placed on the influence of raw material grain size and briquette size on the effective thermal diffusivity. The results obtained for both fine and coarse powder batches indicate that the effective thermal diffusivities are relatively unaffected by raw material grain size, and thus are not influenced by the reaction pathway and initial melt phase formation. On the other hand, analysis of the heat flux derived from conduction heat transfer (Q c ) and heat flux passing through cavities between briquettes (Q cav ) revealed that the briquette size has a strong influence on the effective thermal diffusivity of the batch blanket. The thermal diffusivity observed for flake-type briquettes (2–5·6 mm) is the same as for powder raw materials. The likely reason is that the contact heat resistance increases when many small briquettes are stacked in the batch blanket, and thus the conduction heat transfer is decreased. Clearly, for small briquettes of coarse raw materials (18·6 mm × 13·5 mm × 3·7 mm), the main factor for improving the thermal diffusivity was improving the conduction heat transfer. Additionally, for large briquettes of coarse raw materials (38 mm × 38 mm × 21 mm), the thermal diffusivity can be improved via both conduction and radiant heat transfers through the cavities between briquettes. The results clarified that both Q c and Qcav can be effectively tuned by adjusting the briquettes size. In addition, the meltable amount per unit area may be increased compared to the powder raw material, by melting the briquettes with a batch blanket of appropriate thickness.

Frequently, the deviation of attention of an automobile driver due to excessive noise is among the major factors responsible for accidents and at 54·3 dB the sound between 500 to 5000 Hz is the highest noise transmitted to the driver through glass. Thus, there is a strong requirement for the inclusion of acoustical measures while selecting the windshield of cars. The present work includes acoustical properties measurement of laminated glass (LG) having polyvinyl butyral (PVB) and ethyl vinyl acetate (EVA) interlayers of different critical thicknesses using ASTM E1050-98 (sound absorption testing using impedance tube), ASTM C423 (sound absorption testing using scale rooms) and also by a newly conceived method. The experimentation results validated the FE developed using COMSOL. An algorithm developed by the authors based on a conjugate gradient optimization method with an aid of a transfer matrix approach is utilised for estimating the acoustical properties of LG plate. The statistical analysis is performed to establish the dependency on frequency, interlayer type and thickness on sound absorption and also for ensuring that the errors in experimental results are acceptable. It is found that increasing the interlayer thickness reduces the transmitted noise level for both LG-PVB and LG-EVA. LG-EVA with 1·52 mm interlayer having the highest sound absorption whereas LG-PVB with 0·38 mm interlayer transmits the maximum noise. An increase in the frequency of sound results in an increment in the sound absorption.

Traditional inside painting techniques of Chinese snuff bottles have developed over more than 200 years into a popular form of Chinese folk art, often based on glass snuff bottles with painted decoration on the inside. The craftsmen who make these pieces usually pay more attention to inside painting skills and overlook their own artistic expression. The designs used tend to be repetitive and copies existing designs from other media such as ink painting or photographs. In this research, a body of inside painted glass works was produced to show how the glass form and painted content were combined. These works also helped to establish possible ways to reduce the limitations of traditional inside painting of Chinese snuff bottles. It has attempted to create a 'new model' for Chinese traditional inside painting through the creation of contemporary glass artworks.

The mass attenuation coefficients, μ/ρ of x(PbO or Bi 2 O 3 ):(100– x )(SiO 2 or B 2 O 3 ) (x=30, 40, 50, 60, 70) glasses at 662 keV were measured according to the data available in the literature on borate glasses and silicate glasses. Theoretical mass attenuation coefficients were calculated by WinXCom software. Theoretical and experimental μ/ρ increased with increasing heavy metal oxide concentration in glass materials. The value of regression analysis as a result of the relationship was calculated to be about 0·999 for the experimental results of both borate glasses and silicate glasses. Such a relationship was not found for the experimental results.

Glass furnaces usually use regenerators to exchange heat from hot flue air to combustion air. The aim of this study is to discuss the effect of different boundary conditions on the heat transfer efficiency in a regenerator, and improve the efficiency of heat transfer for energy-saving. A model based on mass balance and energy balance is provided in this study, while the energy loss and correlation factor are also considered in the model for the accuracy of results. Computational fluid dynamics (CFD) is used to simulate the thermodynamic characteristics in different conditions. The results show that the method is in good agreement with experimental data: the inlet flow rate of flue gas and combustion air has an apparent effect on the outlet temperature of flow stream; the cycle time and the material of the checker bricks have little effect on the outlet temperature; while the effective heat capacity and resident time of gases in channels which are influenced by the cycle time can significantly impact the thermal efficiency of regenerator. These results have important significance for improving energy efficiency and optimising system design in industrial glass production.

The East Window of Agher Parish Church, County Meath in the Republic of Ireland contains a rare survival of a stained glass window by Dublin born artist Thomas Jervais. The window depicting St Paul preaching to the Athenians (after Raphael) was made in 1770 for the Wellesley family home at Dangan Castle, Summerhill, however it was relocated into the nearby church at Agher following a fire, which led to the abandonment of the house in 1809. Jervais was to relocate to London later in 1770, where he spent the rest of his life and gained celebrity for his association with Sir Joshua Reynolds, for whom he painted the West Window of New College Chapel, Oxford in 1778. Jervais was also to be commissioned as glass painter to King George III in 1780, undertaking the painting of the East Window of St George's Chapel, Windsor (now destroyed). Conservation of the East Window of Agher by the York Glaziers Trust in 2016 has revealed fascinating new insights into the early work of this artist. Jervais' approach to glass painting at this stage appears to be experimental and perhaps self taught. Fired paint is complemented by cold paint, multiple layers of glass are used to enhance and intensify tone and colour and evidence has been found for highly unusual applications of silver stain. Jervais appears to have had only a limited range of glasses and materials at his disposal in the making of the window. The glass is pre- dominantly clear, extremely thin and with numerous problematic contortions in its shape, which necessitated a great deal of creativity in its assembly. This paper will highlight the conservation challenges and the technical fabrication of this remarkable window. It will further describe the context of the work of this little known and under-appreciated artist from a chapter of the art history of Ireland that has been to a large degree unwritten and over-shadowed by interest in the Irish artists of the Arts and Crafts movement.