Search

This article extends recent research about the material impact of energy-consuming media technologies by describing the role of oil and its derivatives in the production and consumption of television in the United States after the Second World War. It starts by exploring reasons why the material dimensions of oil have received limited scholarly attention in media history. Then it examines television by describing how the component parts of a TV receiver—the cathode ray tube, the chassis into which it was set, and the cabinet housing the chassis—incorporated elements made with oil. Finally, interpreting prior historiography through the lens of oil, it describes the role these different components played in conflicting discourses about the space of the home, especially the living room, in postwar America. [ABSTRACT FROM AUTHOR]

This paper presents an alternative way to recycle cathode ray tube glass waste, together with fly ash and kaolin, into new glass ceramic materials. The samples were obtained using three firing temperatures: 700, 800, and 900 °C. The effect of the fly ash/CRT waste ratio upon the materials' firing shrinkage, apparent density, apparent and total porosity, chemical stability, and compression strength was investigated. The firing shrinkage used as a dimensional stability parameter, a firing shrinkage range between 2.19–8.18%, was positively influenced by the waste mix amount. The apparent density of the obtained materials is positively affected by the heat treatment temperature, rising from 2.09 to 2.93 (g·cm−3), while the apparent porosity decreases with the increase of the firing temperature from 6.08 to 2.24 %. All the studied glass ceramics show very good chemical stability and complete immobilization of the Pb2+ and Ba2+ ions in the glass ceramic matrix. The compression strength of the sintered materials ranges between 1.42–11.83 (N·mm−2), being positively influenced by the kaolin amount and negatively influenced by porosity. The obtained results confirm the viability of the proposed alternative to use CRT waste and fly ash together with kaolin to obtain glass ceramic materials that can be used for outdoor paving applications. [ABSTRACT FROM AUTHOR]

Managing discarded waste cathode ray tube (CRT) funnels glass has become a major concern worldwide because it has toxic effects on the environment and human health if the hazardous lead leached to the surroundings. The common way of recycling this waste is by crushing it, where it was used as an alternative fine aggregate for concrete production. But the crushing technique has led to the formation of micro-cracks in the funnel glass products, causing to high lead leaching rate. On the other hand, recycling the CRT funnel glass waste through melting and annealing operations in producing the spherical CRT glass (GS) has proven will not danger the environment due to the leaching of lead. Therefore, this paper explored the feasibility of using GS as partial (20%, 50%) and full replacements (100%) of natural coarse aggregates in concrete. The workability, density, compressive strength, and splitting tensile strength were investigated. Given the importance of materials and exposure, the influence of silica fume content and CRT concrete strength subjected to high temperature were evaluated. Overall, the inclusion of GS increased the workability and decreased the density, but reduced the compressive and tensile strength. The use of GS as coarse aggregates should be limited to below 50% due to its negative impacts on the strength aspects have become obvious. However, the results show that the CRT concrete made with 20% GS and 10% silica fume have comparable properties with the control, 52 MPa where only 7% lower than control concrete. The addition of silica fume able to counteract the negative effect of GS.

The present investigation was aimed at the utilization of alternate materials, emphasizing hazardous industrial products (red mud and cathode ray tubes), as constituents of radiation shielding concrete. The usage of these hazardous industrial products improves the sustainability and performance of the radiation shielding concrete. Five concrete blocks were cast and their density, compressive strength, gamma shielding factors, radiation absorption ratio, and transmission factor were explored. For this purpose, gamma-ray shielding measurements were done with the help of an HPGe detector. Mix-1, with zero contents of red mud and CRTs, had the lowest LAC. The LAC results demonstrated that the shielding performance of the current concretes would be better with the increase in red mud and cathode ray tube glass. The Transmission factor (TF) for the prepared concretes with a thickness of 2 cm varied between 11.9–26.1% at 0.06 MeV, while it varied between 4–13% for a thickness of 3 cm. The TF results showed that the composites with a thickness of 2, 3, or 5 cm are good shields against lower energy radiation. The radiation absorption ratio (RAR) for the prepared concretes is high at low energy, suggesting that these new composites can absorb most of the low-energy photons. The RAR results emphasize that the increase in CRTs in the new composites enhanced the radiation shielding features, and when the CRT glass is at a maximum, more attenuation was achieved. [ABSTRACT FROM AUTHOR]

The elastic and radiation shielding properties of lead-recycled cathode ray tube (CRT) glass were investigated in order to study the possible reduction in the use of toxic lead oxide glass by partial replacement using CRT glass waste. The elastic properties of lead-recycled glass were studied using the pulse-echo ultrasonic technique and it was found that the elastic properties varied with CRT content in the glass. This indicated the existence of some modifying cations in the CRT. The radiation shielding properties of the glass were also studied by means of the calculated mass attenuation coefficient, mean free path, and half-value layer using the WinXCom program. The addition of CRT glass was found to deteriorate the radiation shielding properties of lead glass. However, lead-recycled CRT glass still exhibited better radiation shielding properties than the conventional barite concrete. Therefore, lead-recycled CRT glass can be a potential candidate for radiation shielding applications.

The cathode ray tube (CRT) is a common and important tool that has been in use for decades, with which behavioral and visual neuroscientists deliver specific visual images generated by computers. Considering the operating principle of the CRT, the image it presents can flick at a constant rate, which will introduce distractions to the visual experiments on subjects with higher temporal resolutions. While this entrainment has been proved common in recordings of the primary visual cortex of mammals, it is uncertain whether it also exists in the intermediate to deep layers of pigeon's optic tectum, which is relevant to the spatial attention. Here, we present continuous visual stimuli with different refresh rates and luminances couples shown on a CRT to pigeons. The recordings in the intermediate to deep layers of optic tectum were significantly phase locking to the refresh of the CRT, and lower refresh rates of the CRT with higher brightness more likely introduced artifacts in electrophysiological recordings of pigeons, which may seriously damage their visual information perception. [ABSTRACT FROM AUTHOR]

Development and innovation in computer technology have led to the generation of large quantities of end-of-life computing equipment with the attendant challenge of environmentally sound management, especially in developing countries. This study evaluated the heavy metal contents of the cathode ray tube (CRT) and the plastic casing of thirty (30) end-of-life computer monitors of different brands, years of manufacture (spanning 1981-2005) and countries of manufacture. The specimens were analysed for Pb, Cu, Cr, Zn, Cd, and Ni using atomic absorption spectrophotometer after acid digestion. The mean concentrations of metals in the CRTs varied widely: 1400-14300 mg/kg for Pb; 291-1750 mg/kg for Zn;

The safe disposal of waste cathode ray tubes (CRTs) has always been a serious problem due to the stable microstructure of toxic lead (Pb) located in glass. Thousands of researches have been trying to explore environmental and efficient ways to dispose of waste CRTs. To recycle lead from waste CRT funnel glass effectively, a mechanochemical reduction method has been developed in this research. Aluminum was used as a reductant, and the hydrochloric acid solution was used in the leaching process to separate lead from the solution. After mechanochemical ball milling with aluminum, lead ion in CRT funnel glass was transferred into nano-sized element lead. Lead recovery from CRT funnel glass increased significantly as compared to non-activated leaded glass. Approximately 40 % of lead was leached after mechanical activation without aluminum, while over 96 % of lead in the CRT funnel glass could be recovered after mechanochemical reduction with aluminum. Lead chloride (PbCl 2 ) can be recycled from the leaching solution after cooling crystallization. Nano-sized Pb formation and the structural changes of leaded CRT funnel glass by mechanochemical reduction process contributed to obvious improvement in lead recovery. This research provided a high-efficiency and feasible approach for recovering lead in form of PbCl 2 crystal from leaded glass., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The crystallization mechanisms for the formation of glass-ceramics by sintering CRT glass with kaolin-based precursors were investigated by quantitatively determining the crystalline and amorphous phases in the products. Amorphization of sintered products was observed in CRT/kaolinite and CRT/mullite glass-ceramics systems at 700–900 °C. With the increase of temperature, the crystallochemical formation of lead feldspar and orthoclase was detected. Orthoclase was found to be the major crystalline phase in both CRT/kaolinite and CRT/mullite systems at 1000–1100 °C. When the temperature increased to 1000–1100 °C, lead feldspar was formed as the only crystalline phase to host Pb. The leaching tests suggested that the glass-ceramic product sintered by CRT/kaolin-based precursors has stronger resistance against acid attack because of the incorporation of lead into lead feldspar crystal protected by glass matrix. The incorporation of CRT glass into glass-ceramics provides a promising strategy for reducing the environmental hazard of CRT glass. [ABSTRACT FROM AUTHOR]

In this study, soil contamination by toxic metals released from cathode ray tubes (CRTs) openly discarded within the vicinities of artisans' workshops in Nigeria was assessed in order to ascertain the metal leaching potential of CRTs, mobility and bioavailability of the leached metals in soil. Furthermore, the ecological geochemistry of the impacted soils was carried out. Seventy soil samples were randomly collected from thirty five locations at depths 0 - 15 cm (topsoil) and 15 - 30 cm (sub-soil), respectively from two selected states each within five geographical regions of Nigeria. Environmentally available lead (Pb), cadmium (Cd), chromium (Cr), nickel (Ni) and copper (Cu) were extracted from dried and sieved soil samples using aqua regia solution and were analyzed using flame atomic absorption spectrometry (AAS). Additionally, the metals were also sequentially extracted into five fractions and their concentrations determined using AAS. Concentration of Pb ranged from 0.4 - 6510 mg/kg with all top-soils exceeding the Nigerian NESREA regulatory limit of 164 mg/kg while Cd, Cr, Ni and Cu levels were within their respective regulatory limits. Geoaccumulation index values indicated that approximately 83% of all top-soils represented strong to extreme contamination by Pb while sequential extraction showed that majority of the extracted Pb was in the Fe-Mn oxide, residual and exchangeable forms. The results generally suggest that CRT disposal areas are highly polluted with Pb with significant amounts in bioavailable phases. Thus, waste CRTs are required to be managed in an environmentally sound manner to forestall any probable harm to ecological functioning of such areas. [ABSTRACT FROM AUTHOR]

Development and innovation in computer technology have led to the generation of large quantities of end-of-life computing equipment with the attendant challenge of environmentally sound management, especially in developing countries. This study evaluated the heavy metal contents of the cathode ray tube (CRT) and the plastic casing of thirty (30) end-of-life computer monitors of different brands, years of manufacture (spanning 1981-2005) and countries of manufacture. The specimens were analysed for Pb, Cu, Cr, Zn, Cd, and Ni using atomic absorption spectrophotometer after acid digestion. The mean concentrations of metals in the CRTs varied widely: 1400-14300 mg/kg for Pb; 291-1750 mg/kg for Zn; <0.1-129 mg/kg for Cu; <0.1-15 mg/kg for Ni; <0.1-16.3 mg/kg for Cr, and <0.1-4.0 mg/kg for Cd. The Pb concentrations of all the CRT samples, with mean 5120±3000 mg/kg (range: 1400- 14300 mg/kg), exceeded the 1000 mg/kg Pb limit in the EU Directive on the Restriction of Hazardous Substances (RoHS) and the Total Threshold Limit Concentrations (TTLC) used by the USA Department of Toxic Substances and Control (DTSC), for characterizing waste as hazardous. For the plastic casings, the Cu and Cd concentrations in 10 % and 20 % of the samples respectively, exceeded the TTLC. The results of this study show that the CRTs are hazardous waste requiring environmentally sound management and the crude methods of management in Nigeria which include disposal at open dumpsites and surface water, as well as recycling using crude techniques are highly dangerous, exposing man and the ecosystem to toxins. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Liquid Crystal & Displays is the property of Chinese Journal of Liquid Crystal & Displays and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Management of waste electrical and electronic equipment (WEEE) has recently attracted worldwide attention because of high metal concentrations in them. Evolution of toxic and precious metals utilized in WEEE can not only reflect the adventure of eco-design, but can also guide the final recycling option. Pb, As, Cu, Au, Sn and Ag were determined in 10 composite samples of printed circuit boards of cathode ray tube televisions (TV–PCBs) that were produced between 1980 and 2005. The obtained results indicated that average metal concentrations in all TV–PCBs were – Cu: 10.6 ± 4.1%, Sn: 4.21 ± 0.90%, Pb: 3.15 ± 0.54%, Ag: 0.0215 ± 0.0068%, Au: 0.0068 ± 0.0049% and As: 0.0007 ± 0.0004%. No remarkable difference was found in compositions of Pb and Sn over the years, suggesting that there were no major modifications of Sn/Pb solder used in joining the circuitry system. The average composition of Cu fluctuated between 5.10% in 1980 and 12.8% in the mid-1990s and decreased afterwards. The decreases in Ag and Cu compositions could possibly be associated with thinner layers of these metals in newer model products. [ABSTRACT FROM PUBLISHER]

• Waste cathode-ray tube (CRT) glasses are reported. • Recycled CRT glasses are studied for nuclear shielding applications. • A good agreement between the theory and the simulation. • CRT can be considered as building materials in medical facilities. In view of the low market demand and toxic elements contained in cathode ray tubes (CRT), a sustainable method of recycling CRT glasses has become important from the perspectives of waste management and the ecosystem. This research investigated the environmental and economic benefits of the panel (PCRT) and cone (CCRT) glasses, from conventional CRT, as building materials in medical and nuclear facilities. The chemical composition of the two glasses was quantified using X-ray fluorescence (XRF) equipment. The nuclear shielding ability of the CCRT and PCRT was investigated by estimating interaction parameters directly linked to photons, charged particles (CP) (β, H+, He2+, and C6+), fissile neutrons, and thermal neutrons. The mass attenuation coefficients (MAC) of the glasses were determined by FLUKA simulations and XCOM. The CP stopping powers and range were computed using the ESTAR, PSTAR, ASTAR, and SRIM software. The cross sections for fast and thermal neutrons were used to determine the neutron moderating and absorption abilities of the two glasses. The CCRT showed greater gamma, fast neutron, thermal neutron, and CP attenuation capacity relative to the PCRT. The CCRT thus contributes more to the radiation shielding competence of CRT than the PCRT. The photon shielding proficiency of the glasses was found to be superior to many standard shielding materials. Hence, PCRT, CCRT, and therefore CRT could improve the shielding capacity of a medium. The use of CRT glass for producing radiation-protective glasses is a viable way of eradicating waste CRT from the environment. [ABSTRACT FROM AUTHOR]

Psychophysical and physiological studies of vision have traditionally used cathode ray tube (CRT) monitors to present stimuli. These monitors are no longer easily available, and liquid crystal display (LCD) technology is continually improving; therefore, we characterised a number of LCD monitors to determine if newer models are suitable replacements for CRTs in the laboratory. We compared the spatial and temporal characteristics of a CRT with five LCDs, including monitors designed with vision science in mind (ViewPixx and Display++), prosumer gaming monitors, and a consumer-grade LCD. All monitors had sufficient contrast, luminance range and reliability to support basic vision experiments with static images. However, the luminance of all LCDs depended strongly on viewing angle, which in combination with the poor spatial uniformity of all monitors except the VPixx, caused up to 80% drops in effective luminance in the periphery during central fixation. Further, all monitors showed significant spatial dependence, as the luminance of one area was modulated by the luminance of other areas. These spatial imperfections are most pronounced for experiments that use large or peripheral visual stimuli. In the temporal domain, the gaming LCDs were unable to generate reliable luminance patterns; one was unable to reach the requested luminance within a single frame whereas in the other the luminance of one frame affected the luminance of the next frame. The VPixx and Display++ were less affected by these problems, and had good temporal properties provided stimuli were presented for 2 or more frames. Of the consumer-grade and gaming displays tested, and if problems with spatial uniformity are taken into account, the Eizo FG2421 is the most suitable alternative to CRTs. The specialized ViewPixx performed best among all the tested LCDs, followed closely by the Display++; both are good replacements for a CRT, provided their spatial imperfections are considered.

A novel and effective process for extracting lead from the hazardous waste Cathode Ray Tubes (CRT) funnel glass is presented. The technological breakthrough of this process is introducing the discarded CRT funnel glass to traditional lead smelting. In this study, the influences of amount of carbon addition, calcium-silicate ratio, temperature, holding time and funnel glass addition on lead extraction efficiency were investigated to determine the optimal operational parameters. With a glass addition of less than 30 wt%, a high extraction yield of 97.5% of lead from the mixture of funnel glass and lead slag was successfully obtained by controlling the C/PbO molar ratio, CaO/SiO 2 ratio, temperature, treatment time at 0.9, 0.8, 1200 °C, 60 min, respectively. The main crystalline phases of the residues were calcium silicate slag, and an amorphous glass phase appears at a glass addition more than 30 wt%. Thermodynamic calculation shows that the proportion of liquid phase in the slag first increased and then decreased, when the addition of glass is increased, while the viscosity of the slag exhibited a continuous decrease. Thus, based on all the results, it is concluded that the process proposed in this paper is an effective and promising approach for reutilization of obsolete CRT funnel glass. [ABSTRACT FROM AUTHOR]

In the reduction-melting process, lead can be recovered from cathode ray tube funnel glass (PbO = 25 wt%); however, resulting glass residues still contain approximately 1–2 wt% of unrecovered lead. For environmental protection in the residue disposal or recycling, it is important to evaluate the quantities of water-soluble species among the unrecovered lead. This study examined water-soluble lead species generated in the reduction-melting process of the funnel glass and factors determining their generation. In the reduction-melting, metallic lead was generated by reducing lead oxides in the glass, and a part of the metallic lead remained in the glass residue. Such unrecovered metallic lead can dissolve in water depending on its pH level and was regarded as water-soluble lead. When 10 g Na 2 CO 3 was added to 20 g funnel glass during reduction-melting, the resulting glass contained high concentrations of sodium. In a water leaching of the glass, the obtained leachate was alkalized by the sodium-rich glass (pH = 12.7–13.0). The unrecovered metallic lead in the glass was extracted in the alkalized leachate. The quantity of the unrecovered metallic lead (water-soluble lead) in the glass decreased when the melting time, melting temperature, and carbon dosage were controlled during reduction-melting. [ABSTRACT FROM AUTHOR]

The Einsteinian revolution, which began around 1905, was one of the most remarkable in the history of physics. It replaced Newtonian mechanics, which had been accepted as completely correct for nearly 200 years, by the special and general theories of relativity. It also eliminated the aether, which had dominated physics throughout the nineteenth century. This paper poses the question of why this momentous scientific revolution began. The suggested answer is in terms of the remarkable series of discoveries and inventions which occurred in the preceding decade (1895-1904) and which were the result of technological developments in instrumentation. The paper gives a survey of these inventions and discoveries, which include X-rays, radioactivity (radium and alpha, beta and gamma rays), the electron, wireless transmissions across the Atlantic and the patenting of the first thermionic valve. An attempt is then made to show that it was these developments, which gave rise to special relativity. [ABSTRACT FROM AUTHOR]

Objective: To present a new stimulation method based on the use of a head-mounted display (HMD) during pattern reversal visual evoked potential (PR-VEP) testing and to compare variables of HMD to those of conventional cathode ray tube (CRT). Methods: Twenty-three normal subjects without visual problems were recruited. PR-VEPs were generated using CRT or HMD stimuli. VEP outcome measures included latencies (N75, P100, and N145) and peak-to-peak amplitudes (N75-P100 and P100-N145). Subjective discomfort associated with HMD was determined using a selfadministered questionnaire. Results: PR-VEPs generated by HMD stimuli showed typical triphasic waveforms, the components of which were found to be correlated with those obtained using conventional CRT stimuli. Self-administered discomfort questionnaires revealed that HMD was more comfortable in some aspects. It allowed subjects to concentrate better than CRT. Conclusion: The described HMD stimulation can be used as an alternative to the standard CRT stimulation for PRVEPs. PR-VEP testing using HMD has potential applications in clinical practice and visual system research because HMD can be used on a wider range of subjects compared to CRT. [ABSTRACT FROM AUTHOR]