Glass Panels Research Articles

Design And Development Of An External Glass Wall Cleaning System

The increasing number of skyscrapers calls for an increasing demand for regular maintenance and cleaning of the large glass panes or windows of these buildings. Cleaning these windows, is not only tough and a risky job but also time consuming. Thus, an effort has been made to introduce a new system which not only reduces the human effort but also aims in cleaning the windows effectively as well as efficiently. This project aims to produce a clean view through the windows which helps in maintaining the aesthetic view of the building. This device can be used periodically for efficient cleaning of the external glass walls, as there is no involvement of a human being suspended from the top of the building. The Current device can be used as a replacement for an existing method in order to ensure safety of the workers.

Исследование влияния материала оконного профиля на однослойную стеклянную панель в условиях стандартного огневого воздействия

Purpose. To develop a method for calculating the fire resistance of a single-layer flat glass panel enclosed in a frame under the conditions of standard impact during various fire loads, taking into account the design features of the frame and the thermophysical properties of air, fume gases and the frame. Methods. Calculations of the temperature and stress distribution of a bounded glass panel are performed numerically using the FlexPDE software package. Findings. The distribution of temperature and stresses in a single-layer flat glass panel enclosed in a window profile is calculated, taking into account the temperature dependence of the thermophysical characteristics of glass, air and flue gases, the design features of the translucent structure and the nonlinear nature of the change in the ambient temperature during a fire. The effect of the material of the window profile on the destruction of a single-layer flat glass panel enclosed in a frame under conditions of standard fire exposure under various fire loads has been investigated. Application field of research. The results of the study can be used in the design of buildings and structures to ensure safe operation and evacuation in the event of a fire.

Effect of non-uniform temperature exposure on the out-of-plane bending performance of ordinary laminated glass panels

Among the open design issues for structural laminated glass (LG) elements, their mechanical performance during fire exposure stands as a safety concern. This issue is the focus of this paper. An experimental investigation is conducted to evaluate the effect of non-uniform thermal gradients on the out-of-plane bending capacity of standard LG specimens. The pre-fracture, cracking, and post-fracture performances of LG panels were examined using a three-point bending setup. The bending tests were carried out on un-heated LG samples and heated samples, which were either hot or cooled down. The reliability of available analytical and numerical methods to predict the out-of-plane bending performance of LG is then investigated. The accuracy of the analytical and numerical methods was found to be highly affected by the non-uniform thermal boundaries, as well as by the assigned material properties, which are highly sensitive to the fire exposure.

A phase-field thermomechanical framework for modeling failure and crack evolution in glass panes under fire

This paper presents a novel phase-field thermomechanical modeling framework for predicting complicated behaviors of thermal cracking in glass panes under fire. The main idea is to incorporate the proposed mathematical model, which calculates the exact deformation of the mesh elements, into the variational phase-field model to simulate the thermal fracture behavior in glass panes in an effective manner. The developed model improves upon previous attempts to predict thermal cracking in the following ways: (1) in a major departure from the classical phase-field simulation of thermomechanical fracture, crack evolution can be predicted using only temperature distributions; the phase-field formulations are kept fixed to overcome mesh dependency and convergency; (2) the new modeling framework directly transforms temperature variations into thermal strains (rate of loading) using fewer mesh elements and a larger time step, thus substantially reducing the computational effort; and (3) the proposed model can simultaneously predict multiple cracks distributed in any arbitrary space in the glass panes more realistically than the previous numerical models, regardless of glass pane type and size, fixation method, and thermal loading variation. The proposed coupling model is validated through comparisons against experimental observations and ANSYS simulations. Moreover, the validated model is used to examine for the first time the effect of real engineering influential conditions, namely the heating rate, glass pane size ratio under non-uniform thermal loading, and glass pane fixation with a frame on three sides, on thermal cracking behavior.

Transparent silica aerogel slabs synthesized from nanoparticle colloidal suspensions at near ambient conditions on omniphobic liquid substrates

This paper presents a novel sol-gel method to synthesize large and thick silica aerogel monoliths at near ambient conditions using a commercial aqueous solution of colloidal silica nanoparticles as building blocks. To achieve slabs with high visible transmittance and low thermal conductivity, the method combines the strategies of (i) synthesizing gels on an omniphobic perfluorocarbon liquid substrate, (ii) aging at temperatures above room temperature, and (iii) performing solvent exchange with a low-surface-tension organic solvent prior to ambient drying. The omniphobic liquid substrates were used to prevent cracking and ensure an optically-smooth surface, while nanoparticle building blocks were small (<10 nm) to limit volumetric light scattering. Gels were aged at temperatures between 25 and 80 °C for up to 21 days to make them stronger and stiffer and to reduce shrinkage and cracking during ambient drying. Ambient drying was achieved by first exchanging water in the gel pores for octane, followed by drying in an octane-rich atmosphere to decrease capillary forces. The synthesized nanoparticle-based silica aerogel monoliths had thicknesses up to 5 mm, diameters up to 10 cm, porosities exceeding 80%, and thermal conductivities as low as 0.08 W m−1 K−1. Notably, the slabs featured visible transmittance exceeding 75% even for slabs as thick as 5 mm. The as-synthesized aerogel monoliths were exposed to TMCS vapor to induce hydrophobic properties resulting in a water contact angle of 140° that prevented water infiltration into the pores and protected the aerogels from water damage. This simple synthesis route conducted at near ambient conditions produces hydrophobic aerogel monoliths with promising optically transparent and thermally insulating properties that can be adhered to glass panes for window insulation and solar-thermal energy conversion applications.

Thermal imaging evaluation of the felines paw pad temperature before and after walking: A pilot study

The purposes of this pilot study were to explore the temperature changes of the paw pads in healthy cats before and after a 6-min walking test (6MWT), and to further compare the accuracy of the point and line region of interest (ROI) selection methods of the thermal imaging. Five healthy intact cats were recruited and trained to run on the treadmill, and to keep still during the standing phase on a glass panel when capturing thermographic imaging data. The paw pad temperature was recorded using a thermal camera and then analysed using both the point and line ROI before and after the 6MWT. The symmetry index (SI) between the limbs (left and right) was further calculated. Compared to the baseline, there were significant increases in the paw pad temperature of the forelimbs (point of left P &amp;lt; 0.001, point of right P = 0.048, point of average P = 0.002, line of left P &amp;lt; 0.001, line of right P = 0.007, line of average P &amp;lt; 0.001), hindlimbs (point of left P &amp;lt; 0.001, point of right P &amp;lt; 0.001, point of average P &amp;lt; 0.001, line of left P &amp;lt; 0.001, line of right P &amp;lt; 0.001, line of average P &amp;lt; 0.001), and average value after the 6MWT both using the point and line ROI selection methods. However, there is no temperature difference between the point and line ROI either before or after the 6MWT. In addition, no difference in the SI was found between the baseline and post-test or between the point and line ROI. These results preliminarily indicated that a 6WMT and thermal imaging could be a good combination for further clinical practices to recognise lameness or any other gait disabilities in cats, and both the point and line ROI selection methods can be considered when analysing thermographic data.

Photovoltaic Modules with the Look and Feel of a Stone Façade for Building Integration

The vast majority of photovoltaic (PV) modules feature a glass pane on the front side. Even specialized products for integration into building skins usually have the look and feel of (colored) glass panes. Herein, PV modules that have the look and feel of natural stone façades are presented. This is achieved by either replacing the front glass pane of PV modules with a stone veneer sheet or by laminating veneers of natural stones onto the front glass pane of PV modules, allowing retrofitting of standard PV modules. A wide variety of stones can be integrated in this way into PV modules. One‐cell PV modules are fabricated using 156 mm × 156 mm silicon solar cells and different stone veneers, and power conversion efficiencies up to 11.2% are achieved, compared to 20.7% for a control PV module. Large‐area demonstrator PV modules with a size of 1220 mm × 610 mm are also fabricated using 49 half‐cells that yield up to 8.5% efficiency. The impact of the inhomogeneity of the stone veneers on the performance of the PV modules is analyzed and measures are suggested to reduce the efficiency losses caused by the application of the stone veneers.

Ug-value and edge heat loss of triple glazed insulating glass units:A comparison between measured and declared values

Triple glazed low-e coated insulating glass units with argon filling of five different suppliers on the European market with a declared thermal transmittance in the undisturbed centre of glass (Ug-value) of 0.6 W/m2K have been purchased from resellers and tested in a guarded hot plate at vertical position. The measured results showed deviations towards higher values for all 5 types. These have been analysed by recurring to the determination of the two main factors namely the gas mixture in the two cavities and the emissivity of the coated glass panes. Non-destructive measuring methods for gas mixture analysis and standardized calculation methods for the Ug-value have been used to analyse the influence of these two factors. In a further step the edge heat loss due to the spacer of the insulating glass units has been measured by using two “halves” of each glazing type with a double edge running through the middle of the measured sample. This was done following a standardized test method for the determination of the edge heat loss of Vacuum Insulation Panels (VIP). Finally, pieces of the coated glass panes were cut out of the glazing units and their emissivity measured with both an infrared spectrometer and an emissiometer. Results showed an increased emissivity value for the coated surfaces leading to higher Ug values than measured. This is partly due to the exposure to air and the possible degradation of the coating. The investigation shows non-destructive emissivity determination is needed to get more accurate in-situ emissivity values of the coatings.

BIM based decision-support tool for automating design to fabrication process of freeform lattice space structure

Complex freeform surfaces and structures are increasingly designed and used in the product and building industry due to the advances in mathematics and digital design tools. However, there is still a gap between designing freeform surfaces and fabricating them. The process of preparing freeform surfaces’ shop drawings is complicated, time-consuming, and lacks the mutual understanding among the stakeholders. Computational design and Building Information Modeling (BIM) can serve as a mediator agent for the integration of design goals with the geometric logic of constructability. They can also facilitate creating platforms for designing and evaluating freeform structures. This open-ended qualitative research attempts to develop a systematic methodology for automating the design and construction drafting process of freeform lattice space structure. Solving this complex geometric problem aims to benefit the design for construction and manufacturers and shrink the cost and time of the process. The study employs a 3D computer-aided design (CAD) tool and introduces an algorithm that generates a BIM model. The BIM model contains shop drawings and suggests the specifications of the main elements, such as beams, glass panels, and nodes.

Coupled deformation behavior analysis for the glass panel in unitized hidden-frame supported glass curtain wall system

As a kind of building envelope, glass panel has been emerging and widely employed in unitized hidden-frame supported (UHFS) glass curtain wall system in modern construction engineering. In practical service conditions, the large area of glass panels involved in the all-glass facades of UHFS glass curtain wall system usually expose to external wind loads, thus it is quite essential to focus on the coupled deformation of the glass panel caused by complex boundary constraints stemming from connected components and their interactions in UHFS glass curtain wall system. In this paper, the optical measurement system associated with the standard air-tight test chamber of UHFS glass curtain wall samples for DIC analysis of the glass panel was first established based on the theory of stereo vision and digital image correlation. Then, the conventional digital indicators and finite element analysis (FEA) models were employed to provide the actual and theoretical deformation information of the panel, which were used to demonstrate that the adopted DIC method had the unique advantage of characterizing full-field coupled deformation behavior of the glass panel affected by complicated boundary conditions. Consequently, the spatiotemporal deformation behavior of the glass panel in practical service conditions was investigated and thus the principal strain, maximum relative deflection (MRD) as well as strain energy density on the panel surface were accordingly evaluated. The above metrics could be used for failure risk evaluation and providing safety design suggestions for the glass panel in UHFS curtain wall system.

Theoretical Analysis and Experimental Study of Time-Varying Electric Field and Electrostatic Adhesion Force Generated by Interdigital Electrode Arrays

A theoretical model is presented for the analysis of the electric field and electrostatic adhesion force produced by interdigital electrode arrays. The electric field is derived by solving the Laplace equation for the electrical potential in each subregion. The electrostatic adhesion force is calculated using the Maxwell stress tensor formulation. The dynamic properties of the electric field and electrostatic adhesion force are assessed by evaluating the transient response of the field and force under a step in applied voltages. Experimental studies are carried out to evaluate the adhesion performance of an electrode panel on a glass pane, and the experimental results verify the correctness of the theoretical model.

Glazed curtain walls: Thermal transmitance calculation

Glazing is one of the dominant features of modern and contemporary architecture. This envelope design may have a great impact on operational energy demand of buildings. In this work, glazed façade systems available in Argentina are analyzed, with the purpose of determining the associated thermal transmittance ranges, in terms of the profiles’ design, the type of glazing and the size of glass panes. First, by using bidimensional numerical calculation, the impact of several profile design parameters on thermal transmittance is studied, highlighting the relevance of glazing fixing methods, to then calculate the thermal transmittance of the entire facade. The results indicate that the thermal transmittance value of glazed facades, mainly depends on the transmittance of the glass used, and exceeds this by 24% on average.

Design, Development, and Characterization of Low Distortion Advanced Semitransparent Photovoltaic Glass for Buildings Applications

Aesthetic appearance of building-integrated photovoltaic (BIPV) products, such as semitransparent PV (STPV) glass, is crucial for their widespread adoption and contribution to the net-zero energy building (NZEB) goal. However, the visual distortion significantly limits the aesthetics of STPV glass. In this study, we investigate the distortion effect of transparent periodic-micropattern-based thin-film PV (PMPV) panels available in the market. To minimize the visual distortion of such PMPV glass panel types, we design and develop an aperiodic micropattern-based PV (APMP) glass that significantly reduces visual distortion. The developed APMP glass demonstrates a haze ratio of 3.7% compared to the 10.7% of PMPV glass. Furthermore, the developed AMPV glass shows an average visible transmittance (AVT) of 58.3% which is around 1.3 times higher than that of AMPV glass (43.8%). Finally, the measured CIELAB values (L* = 43.2, a* = −1.55, b* = −2.86.) indicate that our developed AMPV glass possesses excellent color neutrality, which makes them suitable for commercial applications. Based on the characterization results, this study will have a significant impact on the areas of smart window glasses that can play a vital role in developing a sustainable environment and enhancing the aesthetical appearance of net-zero energy buildings (NZEB).

Simulation Study on the Influence of Fire Partition on Curtain Wall Temperature in Super High-Rise Buildings in China

The poor fire resistance characteristic of super high-rise curtain wall makes the curtain wall design one of the main approaches to improve its capacity for prevention and control over fire and smoke spread. The propagation of smoke leads to the increase in the temperature of the curtain wall on the upper and lower floors of the fire floor and consequently leads to glass fracture and other serious consequences. Current codes have control over fire resistance performance and size of fire partition materials but do not include requirements on the position of curtain walls on floors. By changing the position of fire partition in curtain walls, the paper carries out three comparative simulation experiments on two forms of fire partition: spandrel and fire prevention cornice. Besides, PyroSim is used to calculate the comparative simulation of fire and smoke spread and obtain the data on temperature variation nephogram and monitoring points in the center line of glass curtain walls during different fire scenarios, so as to discuss the influence of different positions of spandrels and fire canopy on fire hazard and smoke. This study finds out the following: fire canopy can better prevent the longitudinal spread of fire smoke than spandrels. The fire canopy above spandrels can reduce the flue-gas temperature. The higher the spandrels above floors, the faster the temperature of the central lines of glass curtain walls above fire floors reduced. However, the higher the spandrels above floors, the more uneven the distributions of high-temperature regions and low-temperature regions, thus leading to the increase in horizontal temperature differences of glass panels. This research conclusion can be taken as a reference for fire protection design of super high-rise glass curtain wall.

High strain rate response of laminated glass interlayer materials

During a blast event, the polymeric interlayer of laminated glass used in windows and curtain walls plays an essential role in protecting buildings and occupants. In this research, the dynamic constitutive behavior of ultraviolet (UV) cured one-component acrylic resin (UVEKOL-S), Polyvinyl butyral (PVB), and virgin PVB extracted from heat strengthened laminated glass panes were investigated at an average strain rate of 30–40 s−1 using impact drop-weight apparatus. An analytical procedure was developed to simulate the drop weight device and calculate the drop height required for a certain strain rate. A new technique was used to investigate the mechanical properties of PVB, and UVEKOL-S before and after the breakage of the laminated glass, including each material energy absorption capacity. The results show that both PVB and UVEKOL-S, at strain rates of 30–40 s−1, had an initial rise in strength. However, after the maximum stress point, both materials followed a noticeable difference in their response to failure. Comparing the high-strain and static results showed that the dynamic loading significantly affects the material response and the energy absorption characteristics of the interlayer materials, and subsequently, the blast response of laminated glass panels. Sufficient data was obtained from the tests to evaluate alternative approaches to modeling PVB and UVEKOL-S materials in the blast event.

The Road to the Salvation of Mankind: Additions to the Series of Glass Designs by the Crabeth Brothers

The two newly-discovered drawings by the glass painter Dirck Crabeth presented here fit seamlessly into his series The Road to the Salvation of Man, which has long been known. The drawings are the design for the first episode, until recently known only as a glass panel, and the original of the second episode, the copy of which, along with two copies of other episodes are in Museum Catharijneconvent in Utrecht. Stylistic clues have made it possible to date Dirck Crabeth’s drawings and the corresponding surviving glass panels earlier, to around 1545-50. They share the thinking represented in a Lutheran series of prints by Frans Huys dating from around 1560 to a design by Gerard van Groeningen, which was discussed by Daniel Horst. An analysis of the career of the young Wouter Crabeth, his collaboration with Dirck and characteristics of their different styles demonstrates that the three copies in Utrecht could be by Wouter Crabeth, contrary to the recent attribution by Ilja Veldman to the Antwerp artist Pieter Huys, Frans’s brother, and in line with the previously held attribution to one of Dirck’s assistants.

Study on recycled Er-incorporated waste CRT glasses for photon and neutron shielding

The present study is extremely associated with the evaluation of cathode ray tube (CRT) waste which is a growing hazardous waste management and disposal issue. The Er-added recycled glasses derived from CRT have been successfully fabricated as a component for Na2O–Al2O3–SiO2–K2O–CaO–SrO–BaO–PbO–Fe2O3–TiO2–Er2O3 glass systems. The waste cathode ray tube panel glass (WPG) series were obtained by inserting the Er2O3 in substitution for CRT in the amounts of 0, 1, 3 and 5 mol%. The synthesized WPG series were then subjected to numerous characterization analysis. One can firmly report that the insertion ratio from 0 to 5 mol% in Er2O3 increased the glass density from 2.9216 to 2.9763 g/cm3. Further, there exists no crystalline formation with the addition of Er2O3, instead, an amorphous nature in all WPG series emerges. Microstructural images captured by the SEM technique also confirm the non-crystallinity of the fabricated samples. Energy dispersive spectroscopy (EDS) in SEM, besides, paved the way for revealing the elemental mapping of the WPG series. From the perspective of radiation shielding competencies, nuclear shielding features have been evaluated in terms of μm and related attenuation parameters at several photon energies of 276.4–1332.5 keV by utilizing narrow beam transmission methods. The experimental data have been also confirmed to those of theoretical results by WinXCom software. The HVL results revealed superior photon radiation shielding performances for recycled WPG glasses in comparison to various concretes. In addition, exposure buildup factor (EBF) values estimated utilizing the G-P fitting approach would be useful to design or develop the synthesized glass systems for shielding applications. Furthermore, the macroscopic effective removal cross-sections for fast neutron (ΣR) have been estimated. In conclusion, the findings clearly demonstrated that Er-incorporated CRT glasses can effectively be implemented in radiation shielding applications instead of Pb having toxic effects.

Deposition Rates of Asthma Triggers on Conventional and Enclosed Window Treatments

Environmental interventions are an important element of managing allergies and asthma. Health professionals often recommend that draperies be replaced with window blinds however no data exist on accumulation of inhalant allergens or inflammatory bioaerosols on window treatments. Installing blinds that accumulate less dust may reduce breathing zone exposures when blinds are adjusted if hazardous amounts of bioaerosols are deposited. We sought to determine the rate of accumulation of dust, allergens, bacterial endotoxin and fungal glucan on window blinds of two distinct types mounted on the two types of windows most commonly installed in U.S. homes. The blinds tested were conventional horizontal slat blinds hanging on the inside of the window (roomside blinds) and similar blinds placed between the exterior window glass and an extra pane of glass on the interior side (between-glass blinds). The study was conducted in six households as a paired, repeated measures study. Households were identified for participation, having met the study criteria of children and cats living inside a carpeted home. Standard window blinds accumulated cat allergen, endotoxin and fungal glucan at rates of 5940ng/m², 1910EU/m², and 11,360ng/m² per month. Between-glass blinds reduced the loading of asthma triggers by 25- to 185-fold. Comparison with clinical thresholds associated with asthma morbidity indicates that room-side blinds accumulate potentially hazardous quantities of asthma triggers.

Dynamic thermal stress analysis of PCM-glazed unit under intermittent solar irradiation

ABSTRACT In this study, a multi-physics coupled mathematical model was established on thermal stress distribution of double-glazed units with phase-change material (PCM-glazed) for the transient temperature fields and non-uniform intermittent solar irradiation, and the mathematical calculations are in good agreement with the experimental results, which shows that the developed model in present work can solve the coupled thermal stress distribution problem between phase change and intermittent solar irradiation in the PCM-glazed. A case that is the thermal stress distribution on the surface of glazed unit filled with paraffin under the outdoor variable temperature and non-uniform intermittent solar irradiation was studied in autumn in cold region of China. The results show that the stress produced on the surface of glazed unit filled with paraffin varies obvious, PCM layer between the glass panes significantly affects the stress values at different time, which can, respectively, reach up to about 4.59MPa and down to −3.9MPa for tensile and compressive strains once the paraffin in liquid state, due to improved thermal conductivity of PCM throughout phase transition to liquid. Additionally, the frame is the key factor causing temperature gradient of PCM-glazed unit, and the biggest tensile stress appears at the edge. The influence range of the frame on the surface temperature and stress of the PCM-glazed unit is limited and different, and the largest influence distance of the surface temperature and stress from the edge is 0.1 m and 0.03 m, respectively.

Improved thermal stability of antireflective moth-eye topography imprinted on PMMA/TiO2 surface nanocomposites

The thermal stability of antireflective moth-eye topographical features fabricated by nanoimprint lithography on poly (methyl methacrylate) (PMMA) incorporating TiO2 nanoparticles is explored. The effect of nanoparticle load on the relaxation dynamics of the moth-eye nanostructure is evaluated via grazing incidence small angle x-ray scattering measurements by in situ monitoring the structural decay of the nanopatterns upon thermal annealing. It is demonstrated that the incorporation of TiO2 nanoparticles to the imprinted surface nanocomposite films delays greatly the pattern relaxation which, in turn, enhances the stability of the patterned topography even at temperatures well above the polymer glass transition (Tg). The improved thermal behavior of the antireflective films will significantly enhance their functionality and performance in light-trapping applications where temperatures typically rise, such as solar devices or solar glass panels.