{"title":"Effective thermal conductivity of fiberglass insulation","authors":"Manoj K. Choudhary, Walter Eastes","doi":"10.1111/ijag.16652","DOIUrl":"10.1111/ijag.16652","url":null,"abstract":"<p>Globally, the operational energy usage in buildings accounts for about 30% of the final energy consumption and 26% of the energy-related emissions. In 2022, the building sector recorded 132 EJ in energy usage and 9.8 Gt of CO<sub>2</sub> emissions. Energy-intensive space heating and air conditioning play a significant role in these statistics, with slightly over half of US home energy usage attributed to them. Thus, energy-efficient buildings, incorporating effective thermal insulation, are essential for addressing climate change. Fiberglass is the dominant insulation material used in US homes, comprising about 71% of installations. The paper discusses the fundamental aspects of heat transfer in fibrous insulation in general and fiberglass insulation in particular. The thermal performance of a fibrous insulation is characterized by an effective thermal conductivity, which combines conductive and radiative terms. The former represents heat conduction through the gas–fiber network and the latter the absorption and the scattering of thermal radiation by the fibers. The paper describes mathematical formulations for these terms and presents results showing the dependence of the effective conductivity on insulation density, fiber diameter, and temperature. The predicted values of the effective conductivity are found to be in good agreement with the measured ones.</p>","PeriodicalId":13850,"journal":{"name":"International Journal of Applied Glass Science","volume":"15 3","pages":"307-316"},"PeriodicalIF":2.1,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139055883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Luiz Pereira, Sophie Schuller, Fabian B. Wadsworth, Jérémie Vasseur, Ricardo F. Lancelotti, Kai-Uwe Hess, Stéphane Gossé, Donald B. Dingwell
{"title":"Rheology of a sodium-molybdenum borosilicate melt undergoing phase separation","authors":"Luiz Pereira, Sophie Schuller, Fabian B. Wadsworth, Jérémie Vasseur, Ricardo F. Lancelotti, Kai-Uwe Hess, Stéphane Gossé, Donald B. Dingwell","doi":"10.1111/ijag.16650","DOIUrl":"10.1111/ijag.16650","url":null,"abstract":"<p>During glass production, phase separation can result in the formation of suspended liquid droplets, which can cause changes in the system rheology. In nuclear waste vitrification context, some new glassy matrices may present this phase separation matter, but the mechanisms controlling the viscosity changes have not yet been determined. Here, we measure the viscosity of a sodium-borosilicate melt containing dissolved MoO<sub>3</sub> at different temperatures and subject to different applied shear strain rates. We observe that (i) the viscosity increases sharply as the temperature decreases and (ii) at any constant temperature below 1000°C, the system presents non-Newtonian response. Using transmission electron microscope observations coupled with viscosity calculations, we interpret the cause of the observed changes as the result of phase separation. We show that the viscosity increase on cooling is in excess of the predicted temperature dependence for a homogeneous melt of the starting composition. The increase is due to the formation of a second phase and is controlled by chemical and structural modifications of the matrix during the loss of the elements that form the droplets. This work provides insights into the rheology of a system composed of two composition sets due to a miscibility gap.</p>","PeriodicalId":13850,"journal":{"name":"International Journal of Applied Glass Science","volume":"15 2","pages":"127-138"},"PeriodicalIF":2.1,"publicationDate":"2023-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/ijag.16650","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138717441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Thermally matched chalcogenide glasses with high refractive index contrast for infrared graded-index lenses","authors":"Qian Chen, Anping Yang, Cheng Ma, Zhijie Yang, Zijun Liu, Xiang Shen, Zhiyong Yang","doi":"10.1111/ijag.16651","DOIUrl":"10.1111/ijag.16651","url":null,"abstract":"<p>Infrared graded-index (GRIN) lenses are desirable for realizing miniaturization and lightweight of infrared imaging systems. Chalcogenide glasses have excellent infrared transparency, good rheological property, and large refractive index range, making them preferred materials for infrared GRIN lenses. In this work, aiming to find thermally matched chalcogenide compositions with high refractive index contrast for preparing GRIN glasses by the stacking diffusion approach, we investigated characteristic temperature, thermal expansion coefficient and refractive index of Ge-As-Se and Ge-As-Se-Te glasses, optimized the glass compositions, and evaluated the feasibility of preparing GRIN glass using the optimized chalcogenide glass powders. It is found that Ge<sub>20</sub>As<sub>20</sub>Se<sub>20</sub>Te<sub>40</sub> and Ge<sub>12</sub>As<sub>22</sub>Se<sub>66</sub> glasses have similar softening temperature (247°C vs. 249°C), reasonably difference of thermal expansion coefficient (3.8 ppm/K), and large refractive index contrast (∼.48). The glass powders with composition xGe<sub>20</sub>As<sub>20</sub>Se<sub>20</sub>Te<sub>40</sub>-(1-x) Ge<sub>12</sub>As<sub>22</sub>Se<sub>66</sub> can be hot-pressed into glass disks with good transmittance at the same temperature and pressure. Graded refractive index profile is formed near the interface between the layers after the co-pressed glass is thermally treated. These results demonstrate the prospect of the compositions for preparing infrared GRIN glasses.</p>","PeriodicalId":13850,"journal":{"name":"International Journal of Applied Glass Science","volume":"15 2","pages":"119-126"},"PeriodicalIF":2.1,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138593946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Modeling and optimization of the sagging process for large-size and high-purity silica glass synthesis","authors":"Chengshuai Li, Suping Yin, Qianli Ma, Haisheng Fang","doi":"10.1111/ijag.16649","DOIUrl":"10.1111/ijag.16649","url":null,"abstract":"<p>Glass sagging is a subsequent process to the CVD process used for large-size and high-purity silica glass synthesis. Physical phenomena taking place in this process are complicated which need an in-depth understanding for better control. In this paper, a comprehensive study is conducted for the sagging process using a level-set and enthalpy-porosity coupled model. With this model, the deforming behavior of glass ingot and evolution of OH uniformly distributed region are well predicted. Then, two performance indices (the effective yield rate and maximum extension radius of OH uniformly distributed region) are proposed based on different applications, and important factors, including geometrical parameters (the ingot initial length, crucible diameter and pedestal height) and operating parameter (the heater power allocation scheme), are explored for their effects on the two indices. The orthogonal test design method is adopted to further determine the collective effects of the four factors. According to the range analysis results, the initial ingot length has the greatest effect, while the crucible diameter has the least effect on the effective yield rate; and for the maximum extension radius, the crucible diameter becomes the major factor, while the pedestal height is the most insensitive factor. The corresponding optimal schemes are proposed for the two indices finally, which are believed to provide useful guidance for improving the sagging process.</p>","PeriodicalId":13850,"journal":{"name":"International Journal of Applied Glass Science","volume":"15 2","pages":"167-181"},"PeriodicalIF":2.1,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138592021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A new perspective for nucleation and nanocrystallization from interfacial energy and nanoscale composition fluctuations in glasses","authors":"Takayuki Komatsu, Tsuyoshi Honma","doi":"10.1111/ijag.16646","DOIUrl":"10.1111/ijag.16646","url":null,"abstract":"<p>Nucleation behaviors in glasses/supercooled liquids (SCLs) such as lithium disilicate Li<sub>2</sub>O–2SiO<sub>2</sub>, cordierite Mg<sub>2</sub>Al<sub>4</sub>Si<sub>5</sub>O<sub>18</sub>, fresnoite Ba<sub>2</sub>TiSi<sub>2</sub>O<sub>8</sub>, and K<sub>2</sub>O–Nb<sub>2</sub>O<sub>5</sub>–GeO<sub>2</sub>/TeO<sub>2</sub> glasses were analyzed and discussed from the interfacial energy <i>γ</i> at SCL–nucleus interfaces and nanoscale composition fluctuations. Based on the fragility concept for SCLs and the intrinsic origin of <i>γ</i>, the magnitude order of <i>γ</i>(fragile SCL) < <i>γ</i>(strong SCL) was proposed to be a crucial guide for an understanding of high homogeneous nucleation rates and prominent nanocrystallization. The role of nucleating agent TiO<sub>2</sub>/ZrO<sub>2</sub> in accelerating the nucleation rate in cordierite-based and β-spodumene-type Li<sub>2</sub>O–Al<sub>2</sub>O<sub>3</sub>–SiO<sub>2</sub>-based glasses was discussed from the new perspective of <i>γ</i>(homoepitaxial-like nucleation) < <i>γ</i>(heteroepitaxial-like nucleation). Ferroelectric nanocrystals such as Sr<i><sub>x</sub></i>Ba<sub>1–</sub><i><sub>x</sub></i>Nb<sub>2</sub>O<sub>6</sub> in borate glasses and fluoride nanocrystals such as CaF<sub>2</sub> are also well understood from the proposed guidelines. The present article provides a new perspective for nucleation in glasses/SCLs, contributing to the comprehensive composition design of new innovative glass-ceramics.</p>","PeriodicalId":13850,"journal":{"name":"International Journal of Applied Glass Science","volume":"15 1","pages":"3-30"},"PeriodicalIF":2.1,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135779568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pavel Ferkl, Pavel Hrma, Jaroslav Kloužek, Albert A. Kruger, Richard Pokorný
{"title":"Cold-cap structure in a slurry-fed electric melter","authors":"Pavel Ferkl, Pavel Hrma, Jaroslav Kloužek, Albert A. Kruger, Richard Pokorný","doi":"10.1111/ijag.16645","DOIUrl":"10.1111/ijag.16645","url":null,"abstract":"<p>As glass batch is charged into an electric melter, a cold cap forms on the glass melt surface. Heat transfer to the cold cap from the molten glass below and the melter atmosphere above determines the melting rate. A mathematical model of the cold cap and the experimental kinetic data of the feed-to-glass conversion that were collected for several simulated low-activity and high-level waste melter feeds allowed us to develop relationships between the internal structure of the cold cap, its properties, its thickness, and the internal heat transfer. This contribution shows the distribution of major crystalline phases and the cumulative evolution of gases within the cold cap. It also examines the temperature, conversion degree, and heating rate the melter feed is experiencing during the passage through the cold cap and their effects on the cold-cap bottom temperature and morphology, which are important for the computational fluid dynamics simulations of melters.</p>","PeriodicalId":13850,"journal":{"name":"International Journal of Applied Glass Science","volume":"15 1","pages":"73-87"},"PeriodicalIF":2.1,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136184171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of ZrSnO4 solid solution on the crystallization behavior of Li2O–Al2O3–SiO2 glasses","authors":"Takato Kajihara, Hiroyuki Hijiya, Satoshi Yoshida, Kakeru Ninomiya, Maiko Nishibori, Hikaru Saito, Shigeru Fujino, Satoshi Hata","doi":"10.1111/ijag.16644","DOIUrl":"10.1111/ijag.16644","url":null,"abstract":"<p>Herein, the crystallization behavior of a Li<sub>2</sub>O–Al<sub>2</sub>O<sub>3</sub>–SiO<sub>2</sub> (LAS) glass system with the addition of ZrO<sub>2</sub> and SnO<sub>2</sub> as nucleating agents was investigated using X-ray diffraction, differential scanning calorimetry, four-dimensional scanning transmission electron microscopy, and X-ray absorption fine-structure measurements. At lower heat-treatment temperatures, the addition of ZrO<sub>2</sub> and SnO<sub>2</sub> afforded a ZrSnO<sub>4</sub> solid solution (SS), whereas at higher heat-treatment temperatures, the ZrSnO<sub>4</sub> SS decomposed, affording tetragonal ZrO<sub>2</sub> and tetragonal SnO<sub>2</sub>. LAS-based crystalline phases, such as β-quartz and β-spodumene phases SS, were formed after the formation of the ZrSnO<sub>4</sub> SS. ZrSnO<sub>4</sub> SS particles a few nanometers in size were present in contact with the β-quartz SS particles a few dozen nanometers in size. This suggests that the ZrSnO<sub>4</sub> SS served as a crystal nucleus for the β-quartz SS, promoting its growth.</p>","PeriodicalId":13850,"journal":{"name":"International Journal of Applied Glass Science","volume":"15 1","pages":"31-43"},"PeriodicalIF":2.1,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135131306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qinghua Wang, Chao Liu, Kai Yin, Yongqi Zhou, Huixin Wang
{"title":"High-throughput laser-based surface functionalization for fabrication of superhydrophobic soda-lime glass","authors":"Qinghua Wang, Chao Liu, Kai Yin, Yongqi Zhou, Huixin Wang","doi":"10.1111/ijag.16643","DOIUrl":"10.1111/ijag.16643","url":null,"abstract":"<p>Rendering transparent materials extreme wettability, for example, superhydrophobicity or superhydrophilicity, has received considerable attention during the past decades. While fabrication of superhydrophobic glass with high processing efficiency and low production cost has always been a challenge. In this work, a laser-based surface functionalization process that combines ultraviolet (UV) nanosecond laser texturing and silicone oil-assisted heat treatment was employed to render glass superhydrophobicity with high process throughput. The wettability transition is attributed to the combined effects of laser texturing that induces hierarchical surface micro/nanostructures and silicone oil-assisted heat treatment that alters surface chemistry and lowers surface energy. The surface transmittance of the laser-based surface functionalized glass samples in the visible spectrum was experimentally measured and analyzed. The laser-based surface functionalized glass sample also exhibited long-term stability in air, mechanical robustness and good self-cleaning property. More importantly, the developed process shows both high process efficiency and cost effectiveness and has potential for applications where superhydrophobic glass is required.</p>","PeriodicalId":13850,"journal":{"name":"International Journal of Applied Glass Science","volume":"15 1","pages":"57-72"},"PeriodicalIF":2.1,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48508197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jeanini Jiusti, Elise Regnier, Norma Maria Machado, Mohamed Leith Ghazzai, Vincent Malivert, Muriel Neyret, François Faure
{"title":"Precipitation of cerianite crystals and its effect on the rheology of a simplified nuclear glass melt","authors":"Jeanini Jiusti, Elise Regnier, Norma Maria Machado, Mohamed Leith Ghazzai, Vincent Malivert, Muriel Neyret, François Faure","doi":"10.1111/ijag.16639","DOIUrl":"10.1111/ijag.16639","url":null,"abstract":"<p>In France, high-activity level wastes resulting from nuclear fission are conditioned in a homogeneous sodium-aluminoborosilicate glass by high-temperature vitrification. The tolerance of even a small fraction of crystals could enable an increase in the waste loadings, in addition to promoting process flexibility. If the waste loading were to be increased in French nuclear glass, cerianite (CeO<sub>2</sub>) crystals could precipitate. In this study, we investigated the cerianite crystallization in a simplified nuclear glass melt at different temperatures, Ce<sub>2</sub>O<sub>3</sub> wt%, and shear conditions. Furthermore, the evolution of the viscosity along with cerianite precipitation was followed. It was found that Ce<sub>2</sub>O<sub>3</sub> is highly soluble in the glass melt, as even for a Ce<sub>2</sub>O<sub>3</sub> wt% as high as 10% wt, the cerianite fraction in dynamic conditions at 1100°C after 8 h of crystallization was less than 1% vol. In addition, shear strongly accelerates cerianite crystallization and a high Ce<sub>2</sub>O<sub>3</sub> content can engender the precipitation of highly branched dendrites. The evolution of the cerianite fraction did not significantly affect the viscosity of the glass melt. Finally, unlike what has been observed in the well-known platinum group metal (PGM)-bearing melts, a glass melt containing .8 vol% of cerianite crystals remains Newtonian.</p>","PeriodicalId":13850,"journal":{"name":"International Journal of Applied Glass Science","volume":"14 4","pages":"502-521"},"PeriodicalIF":2.1,"publicationDate":"2023-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48570115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of TiO2 on the occurrence and distribution of chromium in stainless-steel slag glass ceramics","authors":"Zhifang Tong, Jiaxing Wang, Congcong Xu, Zhaoxun Xie","doi":"10.1111/ijag.16638","DOIUrl":"10.1111/ijag.16638","url":null,"abstract":"<p>Stainless steel slag waste can be used to prepare value-added glass ceramics, which can fix potentially toxic Cr from the slag within the crystalline phase. The occurrence and distribution of Cr during the preparation of glass ceramics has a great influence on the final Cr fixation effect. In this study, the effects of the TiO<sub>2</sub> content on the occurrence and distribution of Cr during the nucleation and crystallization steps and on the final properties of the glass ceramics were systematically studied. In the nucleation stage, with increasing TiO<sub>2</sub> content, the Cr distributed in the spinel containing chromium nuclei first increases and then decreases. In the crystallization stage, Diopside crystal phase nucleates and grows with spinel containing chromium nanocrystals as heterogeneous nuclei. X-ray photoelectron spectroscopy analysis showed that the chromium distributed in the diopside crystals first increased and then slightly decreased as the TiO<sub>2</sub> content increased. The optimal TiO<sub>2</sub> content is 3.4 wt.%, which resulted in 97 wt.% of the total Cr being fixed in the diopside crystalline phase (with a very low Cr leaching concentration of 0.009 mg/L), and a high compressive strength of the final glass ceramic of 267.4 MPa, and a Vickers hardness of 1211.8 HV. The research results provide theoretical and technical support for strengthening Cr fixation to enable harmless and high-value utilization of stainless steel slag for fabricating glass ceramics.</p>","PeriodicalId":13850,"journal":{"name":"International Journal of Applied Glass Science","volume":"14 4","pages":"522-533"},"PeriodicalIF":2.1,"publicationDate":"2023-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43318372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}