Glass Heat Research Articles

Achieving Dual Objectives of Maximizing Transmitted Solar Energy and Minimizing UV Transmission at Vertical Incidence

Abstract. In northern China, exterior window glass significantly impacts heating energy consumption during winter by collecting heat and providing insulation. Additionally, it plays a crucial role in shading by attenuating ultraviolet rays. This paper presents an intelligent optimization algorithm based on genetic algorithms for optimizing the thickness of three-layer insulating glass to maximize solar radiation transmission and minimize ultraviolet radiation below 400nm wavelength, thereby enhancing the glass's heat collection and shading capabilities. The study utilizes MATLAB's genetic algorithm function, running 20 iterations to overcome local optima, achieving an optimal glass thickness configuration of 12mm for each layer. This configuration allows maximum solar energy transmission while substantially reducing UV radiation, balancing energy efficiency with health protection. Future research directions include examining different glass materials' effects on UV blocking, considering climate change impacts on glass performance, and scaling the optimization method for large-scale architectural applications to assess its practical and economic viability. The findings contribute to the development of energy-efficient and health-protective building materials.

Synergistic Effects of Silica and Absorbed Water on the Structure and Properties of Silica Composite Rubber.

To investigate the synergistic effects of silica and absorbed water on the structure and properties of a silica composite rubber (SCR) of cis-1,4-polyisoprene (PI), differential scanning calorimetry analyses were performed. The results show that the specific heat capacity and glass transition point of PI in SCR depend on the silica fraction. In addition, the properties of diffusion and absorption of water change with the silica fractions. The absorbed water exists as nanometer-sized droplets in the polymer networks and affects the glass transition point of PI. It is concluded that the composited silica and absorbed water in SCR exhibit synergistic effects on the structure and thermal properties of SCR.

TRANSPORT TECHNOLOGIES RELATED TO THE RESTORATION OF SHIP CARGO MECHANISMS WITH THE LATEST MODIFIED EPOXIES

The development of transport technologies today requires not only the creation of bases for the optimal technical use of vehicles, their technical operation, but also their maintenance and repair. One of the main tasks of transport technologies is the search for new promising scientific directions and their implementation in practice, as well as ensuring the effective use of the latest technologies and innovative methods for the construction or repair of water transport facilities. In this respect, the use of epoxy-based polymer composites is promising. They are characterised by improved adhesive and cohesive properties compared to other known oligomers, which determines the wide range of their application in water transport. In order to improve the properties of epoxy-based adhesives, additives of different physical nature are introduced into the epoxy matrix at the initial stage of moulding. This paper investigates the effect of the modifier d-ascorbic acid on the thermal properties of epoxies to obtain a material intended for the restoration of ship loading mechanisms. Based on the dynamics of heat resistance as a function of d-ascorbic acid concentration, the optimum content of the additive in the epoxy compound was determined, which is 1,25...1,50 pts.wt.for 100 pts.wt.of epoxy resin. The introduction of a modifier into the epoxy oligomer provides composites with the highest heat resistance values of all the materials studied. The heat resistance values increase from 341 K (for the epoxy matrix) to 352...354 K. The mechanism of increasing the heat resistance of an epoxy matrix in the presence of a modifier is substantiated, which involves the interaction of epoxy resin with an additive and a hardener as a result of chemical reactions. As a result of the reactions of structure formation of the compound based on epoxy oligomer and modifier in the presence of polyethylene polyamine, mainly strong chemical bonds of C-O, NH2, O-NH2, N=O, N-O-H, C=N type are formed, which largely determine the increase of cohesive strength of the newly formed modified epoxy matrices. It should be noted that it is the cohesive strength of the matrix that determines the thermal resistance of the material at elevated temperatures. It was found that the maximum glass transition temperature (333 K) was observed for the modified material containing d-ascorbic acid at 1,5 pts.wt. At this level of additive, the maximum values of both heat resistance and glass transition temperature were observed compared to the original epoxy matrix (327 K). At this modifier concentration, the cross-linking of the compound forms the most cross-linked structural network of an amorphous polymer with the highest number of chemical bonds.

RESEARCH OF THE DESTRUCTION CONDITIONS OF GLAZING OF ENCLOSING STRUCTURES UNDER THE CONDITIONS OF THERMAL INFLUENCE OF FIRE

The article presents the main results of mathematical modelling of the destruction of glazing of enclosing building structures with translucent elements under fire conditions. The authors analyse literature data on calculating the fire resistance of enclosing building structures with glazing. The results show that improving methods for predicting the fire resistance of glazing is relevant. Mathematical models for the numerical study of the behaviour of glazing under the thermal influence of the standard fire temperature regime are substantiated. Mathematical models of the heat transfer process involve using a non-stationary differential equation of heat conduction with boundary conditions of the third kind, accounting for the convective and radiant heat exchange between the air in the room with the fire and the glazing. As a criterion for the destruction of glazing under the influence of fire, the authors establish the temperature resistance parameter, which is determined based on the mechanical characteristics of the glass. The article highlights the relevant data on the study of temperature indicators and the mechanism of glazing failure, using mathematical modelling with well-founded mathematical models. It obtains the results of the thermal calculation by applying the finite difference method for solving the non-stationary differential equation of thermal conductivity. The methodology for determining the time of glazing failure under the influence of the standard temperature regime of a fire using the calculation parameters obtained based on well-founded mathematical models is substantiated. An analysis of the adequacy of the obtained calculation data was carried out by comparing them with the results of experimental studies using statistical criteria. As a result of the analysis, the authors confirmed the validity of the calculation data. A complete factorial experiment was conducted based on well-founded mathematical models, which revealed the regularities of the dependence of the parameters of thermomechanical processes in single-layer glass on its structural characteristics. The revealed regularities have the form of linear regression dependences of the destruction time on the thickness of the glazing and the maximum length of the glass panel without bars. Using the regularities of the dependence of the parameters of thermomechanical processes in single-layer glazing on its structural characteristics, the authors constructed reference tables for evaluating the fire resistance of enclosing structures with glazing. The research obtained new scientific data on the study of the behaviour of glazing of enclosing building structures under the thermal influence of fire through mathematical modelling, which is the basis for improving the methods of calculating the fire resistance of enclosing structures with translucent elements. Keywords: enclosing building structures, glazing, fire resistance limit, calculation method, glass heat resistance.

Dynamical Facilitation Governs the Equilibration Dynamics of Glasses

Convincing evidence of domain growth in the heating of ultrastable glasses suggests that the equilibration dynamics of supercooled liquids could be driven by a nucleation and growth mechanism. We investigate this possibility by simulating the equilibration dynamics of a model glass during both heating and cooling between poorly and well-annealed states. Though we do observe the growth of domains during heating, we find that domains are absent during cooling. This absence is inconsistent with classical nucleation theory. By comparing the equilibration dynamics of our glass with that of two models with kinetic constraints, we demonstrate that dynamical facilitation generically leads to heating driven by domain growth and cooling without domains. Our results provide strong evidence that dynamical facilitation, not nucleation and interfacial-tension-driven domain growth, is the driving mechanism for the equilibration dynamics of glass formers. Published by the American Physical Society 2024

Estimating the energy consumption for residential buildings in semiarid and arid desert climate using artificial intelligence

This research aims to develop predictive models to estimate building energy accurately. Three commonly used artificial intelligence techniques were chosen to develop a new building energy estimation model. The chosen techniques are Genetic Programming (GP), Artificial Neural Network (ANN), and Evolutionary Polynomial Regression (EPR). Sixteen energy efficiency measures were collected and used in designing and evaluating the proposed models, which include building dimensions, orientation, envelope construction materials properties, window-to-wall ratio, heating and cooling set points, and glass properties. The performance of the developed models was evaluated in terms of the RMS, R2, and MAPE. The results showed that the EPR model is the most accurate and practical model with an error percent of 2%. Additionally, the energy consumption was found to be mainly governed by three factors which dominate 87% of the impact; which are building size, Solar Heating Glass Coefficient (SHGC), and the target inside temperature in summer.

Effect of Heat Carrier Particles on Drying Characteristics and Germination Traits of Canola Seeds

PurposeResearch into hybrid drying methods is generally aimed at increasing drying speed while maintaining seed quality. Heat Carrier Particles (HCPs) can be used in fluidized bed drying to accelerate the seed drying process. However, this requires qualitative analysis of seed characteristics.MethodsIn this study, canola seed was mixed with HCPs to accelerate the drying process while maintaining seed quality. The HCPs were steel or glass beads (2.7 mm diameter) mixed with canola seed in proportions of 0%, 25%, 50%, and 100% at different drying temperatures (40, 50, and 60 °C). A fluidized bed dryer was used to monitor the drying process and then the germination ability of the dried seeds was evaluated in the experimental conditions.ResultsThe drying time was reduced when the HCP content was 50% of the sample weight. However, drying time increased when 100% HCP was added. Also, the germination ability of the seeds decreased as the drying temperature increased. A higher proportion of steel beads caused a decrease in germination, while the glass heat carrier (50% at 40 °C) was best for maintaining germination in canola seeds.ConclusionsThe germination rate, shoot length vigor index, root length vigor index, and germination energy were significantly affected by the amount of HCP and the drying temperature. The germination parameters were highest when glass HCP was used, and the drying time was also reduced to an acceptable level in this treatment. The most suitable temperature and percentage of HCP were 40 °C and 25% of glass HCP in sample weight, respectively.

Evaluation of energy efficiency of thermoelectric energy generator system with heat pipes, solar tracker, Fresnel lens and nano-particle fluids

This study investigated the limits of electrical energy production from a thermoelectric generator in a high thermal efficiency system using pure water and nanofluids called aluminum oxide and titanium dioxide. It was aim to provide efficient thermal performance by using a Fresnel lens, solar glass tube, heat pipe and tracking system. Experimental measurements were made between 10:00 and 14:00 on July 26 and 27 in 2023. On each measurement day, the system containing pure water and a nanofluid was compared. The values of parameters such as temperature, solar radiation, wind speed and Thermoelectric Generator (TEG) open circuit voltage were measured instantaneously during the measurements. These data were used to calculate thermal resistance, electrical efficiency and output power. The results showed that the open circuit voltage increased with increasing solar radiation and, therefore, hot side temperature. The calculations showed that the highest open circuit voltage of 2.76 V was obtained with the mechanism using pure water as the working fluid. However, the obtained electrical efficiency ηe and output power Pmax values remained at 1.06 % and 1.058 W, respectively. Numerical and Artificial Neural Network (ANN) models are widely used to save time and cost in determining the optimal operating conditions of the TEG. Therefore, in addition to the experimental study, a numerical model consisting of TEG and a cooling system, and an Artificial Neural Network (ANN) model were also developed in this study. The average absolute errors for Computational Fluid Dynamics (CFD) and electrical results were obtained in the numerical model as 3.47 % and 2.97 %, respectively. In addition, the average absolute errors in the ANN model were obtained as 0.6 %, 0.5 % and 0.27 % for water, Al2O3 and TiO2 nanofluids, respectively.

Optical properties and luminescence behavior of Tb3+-Doped SiO2–Al2O3–BaO–BaF2 oxyfluoride glasses and glass ceramics

In this study, oxyfluoride glasses with chemical composition of 45SiO2–15Al2O3–10BaO–30BaF2-xTbF3 (x = 0.2, 0.4 and 0.6 (mole ratios)) were prepared through the conventional melt-quenching method. Raman and FTIR spectra as well as molar volume calculations proved the creation of more non-bridging oxygens (NBOs) in presence of more TbF3 content. Accordingly, absorption edge in UV–Vis spectra showed a slight red-shift to longer wavelengths. The glass with 0.4 mol ratios of TbF3, exhibited the highest photoluminescence emission and its green-to-blue intensity ratio was 0.66. Therefore, this sample was chosen and heat treated at 630, 650 and 675 °C to prepare glass ceramic samples. For the sample heat treated at 650 °C, photoluminescence intensity increased and green-to-blue intensity ratio reached 0.69. Also, lifetimes of green and blue emissions increased from 3.35 ms to 3.67 ms and from 2.95 ms to 3.10 ms, respectively, when the base glass heat treated at 650 °C. Formation of BaF2 nanocrystals in glass ceramics moved the UV–Vis absorption edge to longer wavelengths significantly. Increment of the weak and dangling bonds in crystallized samples reduced Fermi energy, indirect and direct optical band gap energies from 3.792 eV to 3.301 eV, from 3.522 eV to 3.093 eV and from 4.095 eV to 3.582 eV respectively, which led to higher semiconducting behaviors.

BIM-based environmental assessment of residential renovation projects during the operational phase

ABSTRACT Reducing energy consumption and greenhouse gas emissions to combat global climate change has become an international necessity. A large portion of energy consumption is attributed to old buildings, with increased operational costs and decreased occupational comfort. These buildings require renovation measures that can be viewed as an opportunity to implement sustainable construction and create traditionally designed buildings based on sustainable construction. This study proposes a combination of building information modeling (BIM) with Design Builder and Meteonorm software to evaluate the environmental impact of renovating buildings during the operational phase. The process involved is demonstrated in a case study application to a typical two-story single-family residential building in Tehran city, in which the building’s materials, weight, and volume are determined using Revit software, and Design Builder is used to simulate the renovation effect on various building components – showing that, by combining the most effective insulation, glass, heating system, and doors, a 15% reduction in energy consumption and 44% reduction in CO2 emissions could be achieved. The study significantly advances knowledge in sustainable building practices by introducing a practical framework for decision-making in environmentally conscious building renovations, focusing on such crucial elements as insulation materials, window glass types, heating systems, and door materials. It also provides valuable insights into the practical implications of weather data for accurate environmental forecasting, emphasizing the methodology's applicability and adaptability to similar contexts, as evidenced by its successful application in a real-world case in Tehran.

Modification and Performance of a Rotating Biological Contactor for the Rectification of Synthetic Auramine O dye Wastewater

The disposal of domestic and industrial wastewater into the drainage/atmosphere without treatment is a major source of pollution that endangers the health of the population and needs to be controlled. Despite long been used as a secondary treatment strategy for wastewater, conventional rotating biological contactor (RBC) suffers from the drawbacks of limited surface area for the growth of biofilms. There are persistent problems of less oxygenation capacity, and inefficient mixing resulting in inadequate mass transfer. To address these issues conventional RBC has been modified in the present study by replacing a bank of discs using a rotating drum. The use of a rotating drum in RBC enhanced the biofilm attachment surface area up to 2.29 m2 (?108.2% higher than conventional RBC), thereby improving the working performance. To prevent the dissolved oxygen as a limiting factor, four small aerators were placed as supplement aeration system in the wastewater collection tank of modified RBC. To prevent the influence of atmospheric temperature on biological process, a blast-proof aquarium glass heater was placed in the tank. For experimental work, a 700 ppm pretreated synthetic solution of Auramine-O dye as wastewater was utilized. A constant level of percentage variation in biological oxygen demand (BOD) removal efficiency was observed after 15 days of the experiment. After day-15, the MLSS concentration increased to 2960 mg/L, and the BOD concentration reduced to 12.85 mg/L, resulting in a reduction of 89.86% in BOD, indicating the meeting of effluent discharge standards.

Multi‐featured epoxy composites filled with surface‐modified PTFE powders treated by Na‐naphthalenide system

AbstractThis study aimed to produce new multi‐featured epoxy composites that are advanced in terms of mechanical properties, wear and impact resistance, and glass transition and heat deflection temperatures. Epoxy composites filled with chemically surface‐treated poly (tetrafluoroethylene) (PTFE) powders at various ratios were prepared to obtain these improved properties. The chemical treatment was carried out via a Na‐naphthalenide system. After this treatment, the x‐ray photoelectron spectroscopy results presented the existence of functional groups such as OH, carbonyl groups, and CC unsaturation points on the surface of the PTFE powders. On the PTFE surfaces, while the atomic ratios of carbon and oxygen were substantially increased, the fluorine ratio presented a significant decrease after the chemical treatment. However, the wear rates of the novel composites were highly advanced despite this large decrease in the fluorine ratio on the surface of the PTFE powders. Moreover, functional groups such as OH, carbonyl groups, and CC unsaturation points and spongelike or network structures on the PTFE surfaces provided the opportunity to obtain strong adhesion and interfacial bonding between the surface‐modified PTFE powders and the matrix. Strength and modulus values showed substantial enhancement besides the IZOD impact resistance. All glass transition and heat deflection temperatures were also substantially improved.

Effect of Zn/B molar ratio on the structure, crystallization mechanism and properties of ZnO-B2O3-SiO2 glasses for LTCC applications

ZnO-B2O3-SiO2 glass-ceramics, with the same Si/B molar ratio (0.7) and different Zn/B molar ratios (1.6–2.1) have been prepared by quenching glass melt and heat treatment between 680 °C and 720 °C. DSC analysis has demonstrated that the crystallization activation energy (Ea) of the Zn2SiO4 phase increased with increasing Zn/B ratio, and the glass crystallization process was transformed from a two-dimensional to a one-dimensional growth. DSC curves are consistent with the deformation and viscosity curves and can be attributed to the crystallization behavior of glass. The glass-ceramic with Zn/B = 1.7 sintered at 700 °C for 30 min exhibited the best properties: εr = 6.35; tanδ = 4.3 × 10−3 (11.39 GHz); CTE = 3.8 × 10−6 /K.

Permeable Blocks with Waste Glass as Coarse Aggregate

In order to reduce the negative impact of waste glass and urban heat on the environment, this research aims to use waste glass cullet as an aggregate in concrete paving blocks. This work aims to produce porous pavement using two sizes of waste glass and ordinary Portland cement (OPC). Two layers of paving blocks with different aggregate sizes were planned. The first part of the work was to determine the best OPC content. The results showed that the largest aggregate-based porous paving block had the highest compressive strength and acceptable permeability. Then, designed porous block (DPB) was designed, which consisted of two layers, with the upper layer consisting of small aggregates and the lower layer consisting of large aggregates, and cement mortar (80 wt% cement powder and 20 wt% glass powder) was used as the binder. Compressive strength and permeability were the criteria. The pavement can release heat better than conventional pavements and is safe because of the skid resistance, which meets the criteria.

Testing the Uniformity of Surface Resistance on Large-Format Transparent Heating Glass.

The design of a glazing package containing heating glass can make a window a radiator simultaneously. For such bulky glass to act as an effective radiator simultaneously, it should be possible to provide a constant temperature over the entire surface. The continuous surface temperature of the glass depends on the uniformity of the surface resistance of the resistive layer. This paper will demonstrate the testing of heating glass parameters using a specialised apparatus. The research will mainly focus on measuring the value and distribution of the surface resistance of the transparent heating layer. A thermographic study will verify the results. As the heating glass will be subjected to a toughening process, the effect of the toughening process parameters on the degradation of the transparent heating film will be investigated.

Comprehensive analysis and design optimization of temperature distribution in radiant heaters for cooking applications

The temperature distribution inside a radiant heater for cooking purposes has not yet been fully investigated. A numerical methodology was developed to analyze the heat transfer inside a radiant heater. The numerical methodology was validated by experimental analysis, which showed close agreement for the temperature distributions of the heating coil and glass. Then, a parametric study was performed on the pitch of the heating coil, gaps in the inner coil (i.e., inner gap), and gaps in the outer coil (i.e., outer gap). The outer gap had an insignificant effect on the temperature distribution, but the coil and glass temperatures increased linearly as the pitch and inner gap were decreased. The design of the radiant heater was then optimized in terms of thermal stability. A heat loss analysis was carried out, and the numerical results showed close agreement with the experimental results in the case of 10 % heat loss. The results of this study can be used to predict the performance of a radiant heater and optimize its design.

Synthesis, Characterization, Thermal Stability, and Kinetic Degradation of Cellulose p‐Halide Benzoates in an Ionic Liquid 1‐Butyl‐3‐methylimidazolium Chloride

AbstractCellulose p‐halide benzoates (C‐p‐HB) were synthesized by reacting microcrystalline cellulose (MCC) with p‐halide benzoyl chloride (p‐HBCl) namely; the p‐Iodobenzoyl chloride (p‐IBCl), p‐Bromobenzyl chloride (p‐BBCl), and p‐Nitrobenzoyl chloride( p‐NBCl) in ionic liquid 1‐butyl‐3‐methylimidazolium chloride [Bmim](Cl) at 60 °C for 2 h in the presence of 4‐dimethylaminopyridine (DMAP) as a base. The synthetic products were characterized through infrared spectrometry (FT‐IR), nuclear magnetic resonance (NMR) spectroscopy, XRD, and scanning electron microscopy (SEM). Then, the effects of p‐halide benzoate groups on the thermal degradation of C‐p‐HB esters with DS≈1 were investigated using thermogravimetric analysis under an inert atmosphere from room temperature to 600 °C at a heating rate of 5 °C/min. The DSC analysis was used to determine the glass temperature and heat of the reaction of C‐p‐HB esters. The results indicated that the C‐p‐HB was successfully synthesized in [Bmim](Cl) with a DS≈1. The kinetic parameters were determined by the Coats‐Redfern (CR) method. The corresponding kinetic parameters of the main degradation stages were also determined. The thermal stability of MCC was remarkably decreased through esterification with p‐HBCl. The Criado method was used to determine the most probable degradation functions. Thus, reaction orders F2 and F3 were most probably the functions that describe the degradation of C‐p‐HB.

Analysis of differential scanning calorimetry (DSC): determining the transition temperatures, and enthalpy and heat capacity changes in multicomponent systems by analytical model fitting

We have developed an analytical method to quantitatively analyze differential scanning calorimetry (DSC) experimental data. This method provides accurate determination of thermal properties such as equilibrium melting temperature, latent heat, change of heat capacity which can be performed automatically without intervention of a DSC operator. DSC is one of the best techniques to determine the thermal properties of materials. However, the accuracy of the transition temperature and enthalpy change can be affected by artifacts caused by the instrumentation, sampling, and the DSC analysis methods which are based on graphical constructions. In the present study, an analytical function (DSCN(T)) has been developed based on an assumed Arrhenius crystal size distribution together with instrumental and sample-related peak broadening. The DSCN(T) function was successfully applied to fit the experimental data of a substantial number of calibration and new unknown samples, including samples with an obvious asymmetry of the melting peak, yielding the thermal characteristics such as melting and glass transition temperature, and enthalpy and heat capacity change. It also allows very accurate analysis of binary systems with two distinct but severely overlapping peaks and samples that include a cold crystallization before melting.

Experimental investigation of evaporation characteristics of sessile fuel droplets on a hot surface

Spilled fuel that comes in contact with hot surfaces can cause a fire, and to mitigate this type of fire, we researched the evaporation patterns and heat transfer mechanisms of fuel droplets on such surfaces. Glass heating substrates were used to experimentally investigate the evaporation behavior of acetic acid, ethanol, acetone, ethyl acetate, n-heptane, and cyclohexane. Infrared imaging technology and volume estimation method were used for the experimental analysis. The study revealed various thermal patterns on the surfaces of different droplets. Hydrothermal waves (HTWs), Bénard-Marangoni (B-M) cells, cyclic thermal patterns, and double-vortex thermal patterns were observed on different types of fuel droplet surfaces. The energy absorption and breakage of intermolecular hydrogen bonds are related to the formation of HTWs and B-M cells. As the height of the droplets decreased, the rate at which the six fuel droplets evaporated was observed to decrease initially and then increase. The results of this experiment indicate that the evaporation rate of droplets is largely determined by the saturation vapor pressure.

Exploration of the physical states of riboflavin (free base) by mechanical milling

Amorphous riboflavin (free base) could be produced for the first time via high energy ball milling of a commercial crystalline form (Form I). Importantly, this solid state amorphization process allowed to circumvent chemical degradation occurring during melting as well as the lack of suitable solvents, which are required for amorphization via spray- or freeze-drying. The amorphous state of riboflavin was thoroughly characterized, revealing a complex recrystallization pattern upon heating, involving two enantiotropic polymorphic forms (II and III) and a dihydrate. The glass transition temperature (Tg) and heat capacity (Cp) jump of the amorphous form were determined as 144 °C and 0.68 J/g/°C. Moreover, the relative physical stability of the different physical states has been elucidated, e.g., at room temperature: I > II > III. The following rank order was observed for the dissolution rates in water at 37 °C during the first 4 h: amorphous > III ≈ II > I. Afterwards, a dihydrate crystallized from the solutions of amorphous and metastable crystalline riboflavin forms, the solubility of which was well above the solubility of the stable FormI.