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1.
Materials (Basel) ; 15(15)2022 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-35955250

RESUMO

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.

2.
Materials (Basel) ; 15(4)2022 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-35208038

RESUMO

The potential to use waste glass, including cathode ray tube (CRT) glass, for making new products or as an admixture to existing ones is being intensively investigated. This kind of research intensified particularly in the period after CRT TV sets and computer monitors were replaced in the market by the advanced technology of thin film transistor (TFT) and liquid crystal display (LCD) screens. Cathode ray tube glass represents a considerable part of electronic waste (e-waste). E-waste globally increases at a far higher rate than other solid waste materials. There is a possibility to recycle cathode ray tube glass and use it in the construction industry. This paper shows the test results of physical and mechanical properties of blocks and paving flags. The reference specimen was made with quartz sand, while the other product employed a combination of quartz sand and ground panel cathode ray tube glass. The glass was ground to the fraction 0.25/1.00 mm, which corresponds to quartz sand fineness. The following tests were performed: shape and dimensions, resistance to freeze/thaw and de-icing salts, water absorption, splitting tensile strength and tensile strength by bending. Special attention was paid to the tests of Böhme wear resistance, slip resistance of the top surface of CRT products using a pendulum, radioactivity and leaching. The texture of the experimental concrete products was observed by SEM (scanning electron microscopy) and analyzed. The results obtained by experimental testing unequivocally show that CRT glass can successfully be used for making concrete blocks and paving flags.

3.
Materials (Basel) ; 14(16)2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34442942

RESUMO

This paper presents the testing of the durability of concrete where a part of cement was replaced with ground panel cathode ray tube glass (CRT) finer than 63 µm. The percentage of cement replaced with glass is 5%, 10%, 15%, 20%, and 35%, by mass. The highest percent share of mineral admixtures in CEM II (Portland-composiste cement) cement was chosen as the top limit of replacement of cement with glass. In terms of the concrete durability, the following tests are performed: freeze-thaw resistance, freeze-thaw resistance with de-icing salts-scaling, resistance to wear according to the Böhme test, sulfate attack resistance, and resistance to penetration of water under pressure. A compressive strength test is performed, and shrinkage of concrete is monitored. In order to determine the microstructure of concrete, SEM (Scanning Electron Microscopy) and EDS (Energy Dispersive X-ray Spectroscopy) analyses were performed. The obtained research results indicate that the replacement of a part of cement with finely ground CRT glass up to 15% by mass has a positive effect on the compressive strength of concrete in terms of its increase without compromising the durability of concrete. The results obtained by experimental testing unequivocally show that concrete mixtures made with partial replacement (up to 15%) of cement with finely ground CRT glass have the same freeze-thaw resistance, resistance to freeze/thaw with de-icing salt, resistance to wear by abrasion, and resistance to sulfate attack as the reference concrete. In terms of environmental protection, the use of CRT glass as a component for making concrete is also very significant.

4.
Materials (Basel) ; 14(6)2021 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-33809892

RESUMO

This paper presents a novel approach for the recovery of lead from waste cathode-ray tube (CRT) glass by applying a combined chemical-electrochemical process which allows the simultaneous recovery of Pb from waste CRT glass and electrochemical regeneration of the leaching agent. The optimal operating conditions were identified based on the influence of leaching agent concentration, recirculation flow rate and current density on the main technical performance indicators. The experimental results demonstrate that the process is the most efficient at 0.6 M acetic acid concentration, flow rate of 45 mL/min and current density of 4 mA/cm2. The mass balance data corresponding to the recycling of 10 kg/h waste CRT glass in the identified optimal operating conditions was used for the environmental assessment of the process. The General Effect Indices (GEIs), obtained through the Biwer Heinzle method for the input and output streams of the process, indicate that the developed recovery process not only achieve a complete recovery of lead but it is eco-friendly as well.

5.
Doc Ophthalmol ; 143(2): 185-192, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33847872

RESUMO

PURPOSE: Owing to several factors, peak latencies of pattern-reversal visual evoked potentials (p-VEP) are delayed when viewing liquid crystal display (LCD) monitors compared to those evoked when viewing cathode ray tube (CRT) monitors. However, few studies have examined whether biological factors affect latency in LCD. This study aimed to investigate whether biological factors caused latency changes in LCD among young subjects. METHODS: Twenty-eight subjects (56 eyes) aged 21-29 years (mean ± SD, 22.7 ± 1.7) participated in this study. We recorded output from each eye twice for both CRT and LCD monitors under the same conditions for monocular p-VEP. The peak latencies of three components (N75, P100, and N145) were compared between these two monitors. RESULTS: All peak latencies recorded with LCD were delayed compared to those recorded with CRT: N75, 9.7 ± 2.5 ms; P100, 10.1 ± 3.0 ms; and N145, 8.4 ± 6.2 ms (all p < 0.001). The degree of latency delay varied depending on the components. Moreover, all peak latencies of CRT appeared earlier than standard values of N75, P100, and N145. CONCLUSIONS: These findings suggest that the following aspects should be considered when assessing biological factors that may affect latency: components might influence latency changes; a young age could be related to an early appearance of peak latencies; inter-individual differences might cause latency change. These biological factors should be considered as possible causes for the varying latencies in an LCD monitor. Further studies should include healthy adults with a wider age range to assess the effects of age on latency.


Assuntos
Tubo de Raio Catódico , Cristais Líquidos , Adulto , Fatores Biológicos , Eletrorretinografia , Potenciais Evocados Visuais , Humanos
6.
Artigo em Inglês | MEDLINE | ID: mdl-32809044

RESUMO

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.


Assuntos
Columbidae/fisiologia , Neurônios/fisiologia , Estimulação Luminosa/métodos , Colículos Superiores/fisiologia , Visão Ocular/fisiologia , Córtex Visual/fisiologia , Percepção Visual/fisiologia , Animais
7.
Resour Conserv Recycl ; 157: 104772, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32494109

RESUMO

Currently, in the European Union (EU), e-waste chain performance is assessed by technical indicators that aim to ensure system compliance with collection and recovery targets set by the WEEE Directive. This study proposes indicators to improve WEEE flow monitoring beyond the current overall weight-based approach, including complementary flows and treatment performance. A case study focused on the screen category in France is presented. In 2017, the collection rate of cathode-ray tube screens (CRT) was 68%, while for flat panel display (FPD) generated only 14% was collected. CRT screens have less precious and critical materials than FDP. Thus, elements like cobalt and gold highly concentrated in FPD, have a collection rate two to four times lower than elements such as copper (37%) which represents a high proportion in CRTs. Recycling is the main treatment in France. Nevertheless, the recycling rate per element varies significantly due to the low collection, and also the lack of technology and/or secondary raw materials market. The elements with higher recycling rates are base metals such as copper (28%), followed by precious metals like silver (23%), and gold (13%). Except for palladium, the recycling rate of the critical raw materials targeted in the study ranged from 6% (cobalt) to 0% (e.g. neodymium and indium). The results stress the need for indicators to support the development of WEEE chain from waste management to secondary (critical) raw materials suppliers.

8.
Materials (Basel) ; 13(3)2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-32041268

RESUMO

In the last 15 years, new types of display technologies have increasingly replaced cathode ray tube (CRT) screens, which has led to an increase in landfill of old discarded CRT televisions, which present a great environmental challenge throughout the world due to their high lead content. In addition, environmental awareness has led to greater use of recycled aggregates to reduce the exploitation of existing reserves. This document aims to study the feasibility of incorporating CRT glass waste with recycled aggregate (RA) in combinations for use in civil engineering, more specifically in road bases and sub-bases. For the mechanical and environmental assessment of all of the samples and materials, the following procedures have been performed: the compliance batch test of UNE-EN 12457-4:2004 for RA, CRT, and mixtures; the Percolation Test according CEN/TS 14405 for the mixtures, CRT, and RA; Modified Proctor and load capacity (the California Bearing Ratio, or CBR) in all mixtures without cement addition, and finally, compressive strength of the material treated with cement at different ages of curing. The analysis of the mechanical and environmental properties through different techniques of lixiviation was positive, showing the ability to use CRT for certain dosage percentages mixed with recycled aggregates.

9.
Waste Manag Res ; 37(11): 1170-1177, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31645225

RESUMO

Cathode ray tube televisions (TVs) contributes significantly to the rapidly increasing waste stream of cathode ray tubes in the e-waste. This study mainly focused on the material flow of waste cathode ray tube TVs in China. Currently, waste cathode ray tubes constitute a major part of the total generation of e-waste in China. The study aimed to emphasise the flow of materials in the generated waste cathode ray tube TVs by using stock-based material flow analysis model. The modelling was conducted to investigate the disposable number of obsolete devices, in-use stock, and end-of-life of cathode ray tube TVs. SubSTance flow ANalysis (STAN) software was used to perform the material flow analysis modelling and graphical model of the waste cathode ray tube TVs. The results show that in a period of 10 years, overall about 3241.37 kt of cathode ray tube TVs were net produced in China, containing 183.6 kt of glass, 1718.2 kt of plastic, 243 kt of steel/iron, 153.5 kt of lead, 76.6 kt of copper, 7.8 kt of aluminium, and 1.6 kt of antimony. The results revealed that almost 125 kt of end-of-life cathode ray tube TVs containing about 68 kt of glass, 40 kt of plastic, 9 kt of steel/iron, 6 kt of lead, 3 kt of copper, 0.3 kt of aluminium, and 0.07 kt of antimony were dumped in the period of 10 years. Therefore, the management of waste cathode ray tube TVs required better infrastructure for recycling and better regulation to achieve better results in the high recovery of valuable resources.


Assuntos
Tubo de Raio Catódico , Resíduo Eletrônico , China , Vidro , Reciclagem , Televisão
10.
Resour Conserv Recycl ; 135: 323-334, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30078953

RESUMO

Circular economy strategies encourage, among others, concrete actions to extend the product lifetime. Product's repair and reuse, and component harvesting for reuse, all require the facilitated access to product components. Consequently, a reduction of the disassembly time and the related costs will increase the economic feasibility of product lifetime extension and therefore increase the viability of a circular economy in industrialised regions. Furthermore, disassembly has the potential to significantly increase the recycling yield and purity for precious metals, critical metals and plastics. For this reason, the European Commission and several ecolabels have considered to include design for disassembly requirements in legislation or voluntary environmental instruments. However, up to date, there is no standardised method to evaluate the ease of disassembly in an unambiguous manner with a good trade-off between the efforts required to apply the method and the accuracy of the determined disassembly time. The article proposes a robust method "eDiM" (ease of Disassembly Metric), to calculate the disassembly time based on the Maynard operation sequence technique (MOST). A straightforward calculation sheet is employed in eDiM to calculate the disassembly time given the sequence of actions and basic product information. This makes the results fully verifiable in an unambiguous manner, which makes eDiM suited to be used in policy measures in contrast to the results of prior developed methods One of the innovative aspects of eDiM is the categorization of disassembly tasks in six categories, which provides better insights on which disassembly tasks are the most time consuming and how the product design could be improved. The proposed method is illustrated by means of a case study of an LCD monitor. The presented case study demonstrates how the proposed method can be used in a policy context and how the calculated disassembly times per category can provide insights to manufacturers to improve the disassemblability of their products. The results also demonstrate how the proposed method can produce realistic results with only limited detail of input data.

11.
Waste Manag ; 76: 679-686, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29643009

RESUMO

A novel and effective system was developed for recycling cathode ray tube (CRT) funnel glass wastes. Initially, the combination of nanoscale Fe0 with ball milling promoted lead transfer that was strongly encapsulated in the glass inner structure to the surface of funnel glass and/or adhere to iron substance due to the collapse of SiO bonds. This condition enhanced the dissolution of lead in the acid solution. A high lead extraction rate of 97.8% from funnel glass was achieved through nitric acid leaching by optimizing the operational parameters (Fe0/funnel glass mass ratio, 0.5:1; ball milling time; 72 h). Subsequently, lead sulfate, iron hydroxides, and sodium nitrate were gradually recovered from the acid leachate by using three simple operations, namely, sulfation, alkali neutralization, and salt evaporation. Meanwhile, the leaching results of short-term toxicity characteristic leaching (TCLP) and long-term multiple extraction procedures (MEP) clearly demonstrated that the residual high silica products (after acid leaching) had no impact on the environment and could be used to synthesize high value-added zeolites as raw materials. With the addition of Al sources, the complete conversion of high silica residues into high crystalline zeolites with high cation exchange capacity value was realized by applying an alkaline fusion method during the hydrothermal treatment. Furthermore, lead, NO-3, and SO2-4 concentrations of the resulting drainage were considerably lower than the relevant standard for surface water quality. Therefore, the proposed recycling system provided an eco-friendly and feasible technique for complete reutilization of obsolete CRT funnel glass.


Assuntos
Tubo de Raio Catódico , Nanoestruturas , Reciclagem , Vidro , Ácido Nítrico , Dióxido de Silício
12.
Waste Manag ; 76: 671-678, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29650298

RESUMO

This study quantitatively determined the extraction of lead from CRT funnel glass and examined the mechanisms of thermally reducing lead in the products of sintering Pb-glass with carbon in the pre-heated furnace. The experimentally derived results indicate that a 90.3 wt% lead extraction efficiency can be achieved with 20 wt% of C addition at 950 °C for 3 min under air. The formation of viscous semi-liquid glass blocked the oxygen supply between the interaction of C and Pb-glass, and was highly effective for the extraction of metallic Pb. A maximum of 87.3% lead recover was obtained with a C to Na2CO3 ratio of 1/3 at 1200 °C. The decrease of C/Na2CO3 ratio enhanced the metallic lead recovery by increasing the glass viscosity for effective sedimentation of metallic lead in the bottom. However, with the further increase of temperature and treatment time, re-vitrification of lead back to silicate-glass matrix was detected in both Pb-glass/C and Pb-glass/C/Na2CO3 systems. The findings indicated that with proper controls, using C as an inexpensive reagent can effectively reduce treatment time and energy, which is crucial to a waste-to-resource technology for economically recovering lead from the waste CRT glass.


Assuntos
Tubo de Raio Catódico , Resíduo Eletrônico , Chumbo/química , Carbono , Vidro
13.
J Neurosci Methods ; 295: 45-50, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29197616

RESUMO

BACKGROUND: Visual neuroscience experiments and Brain-Computer Interface (BCI) control often require strict timings in a millisecond scale. As most experiments are performed using a personal computer (PC), the latencies that are introduced by the setup should be taken into account and be corrected. As a standard computer monitor uses a rastering to update each line of the image sequentially, this causes a monitor raster latency which depends on the position, on the monitor and the refresh rate. NEW METHOD: We technically measured the raster latencies of different monitors and present the effects on visual evoked potentials (VEPs) and event-related potentials (ERPs). Additionally we present a method for correcting the monitor raster latency and analyzed the performance difference of a code-modulated VEP BCI speller by correcting the latency. COMPARISON WITH EXISTING METHODS: There are currently no other methods validating the effects of monitor raster latency on VEPs and ERPs. RESULTS: The timings of VEPs and ERPs are directly affected by the raster latency. Furthermore, correcting the raster latency resulted in a significant reduction of the target prediction error from 7.98% to 4.61% and also in a more reliable classification of targets by significantly increasing the distance between the most probable and the second most probable target by 18.23%. CONCLUSIONS: The monitor raster latency affects the timings of VEPs and ERPs, and correcting resulted in a significant error reduction of 42.23%. It is recommend to correct the raster latency for an increased BCI performance and methodical correctness.


Assuntos
Interfaces Cérebro-Computador , Gráficos por Computador/instrumentação , Computadores , Potenciais Evocados , Estimulação Luminosa/instrumentação , Encéfalo/fisiologia , Eletroencefalografia/métodos , Humanos , Transtornos dos Movimentos/fisiopatologia , Tempo de Reação , Processamento de Sinais Assistido por Computador , Máquina de Vetores de Suporte , Fatores de Tempo , Percepção Visual/fisiologia
14.
Waste Manag Res ; 35(9): 958-966, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28681661

RESUMO

This article investigates the effect of a low-impact chemical treatment based on a nitrilotriacetic acid chelating agent on the reactivity of funnel glass derived from discarded cathode ray tubes. Treated and untreated glass has been recycled either as a supplementary cementing material or as a fine aggregate in cementitious mortars. The effect of the treatment on the chemical and morphological properties of cullets, as well as on the solubility in an alkaline environment has been evaluated. Data so far collected underline a change in glass cullets characteristics that consequently affects their behaviour in cementitious mortars, reducing the pozzolanic activity as supplementary cementing material, but strongly decreasing the tendency towards alkali silica reactions when added as a fine aggregate. The leaching behaviour of lead on treated and untreated glass and on derived composites has been determined to verify the sustainability of the prepared materials.


Assuntos
Vidro , Reciclagem , Tubo de Raio Catódico , Chumbo , Dióxido de Silício , Solubilidade
15.
J Hazard Mater ; 324(Pt B): 673-680, 2017 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-27876241

RESUMO

The disposal of waste cathode ray-tubes (CRTs) from old televisions and discarded computer monitors has become a major environmental concern worldwide. In this work, an open-loop recycling method was developed to synthesize zeolites using CRT funnel glass as the raw material. The effects of hydrothermal temperatures and pressure, n(SiO2/Al2O3) molar ratios and hydrothermal time on the resulting products were investigated. The results indicated that hydrothermal temperatures and pressure played critical roles in zeolite synthesis. Amorphous phases were detected at lower temperatures (80-100°C) and pressure (0.47-1.01bar) with n(SiO2/Al2O3)=2.0. At the temperature of 110°C (pressure 1.43bar), NaA formed with a mixture of NaP1 and Faujasite. With further increase in the temperature and pressure, the unstable NaA and Faujasite disappeared, and Hydroxysodalite developed. The influence of n(SiO2/Al2O3) ratios on resulting products revealed a single phase of NaA was formed at the ratio of 1.5 and a mixture of NaA and Faujasite at the ratio of 2.0. Prolonging hydrothermal time, however, could promote zeolite crystallization, and NaA gradually developed with an increase in the time from 2 to 6h at n(SiO2/Al2O3)=1.5. By comparison, crystallization phases were observed only when the time was longer than 8h at n(SiO2/Al2O3)=2.0.

16.
Environ Technol ; 38(13-14): 1696-1701, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27673726

RESUMO

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.


Assuntos
Arsênio/análise , Tubo de Raio Catódico , Resíduo Eletrônico/análise , Metais Pesados/análise , Televisão
17.
Ann Rehabil Med ; 40(2): 334-40, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27152285

RESUMO

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 self-administered 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 PR-VEPs. 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.

18.
Waste Manag ; 57: 198-206, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27211314

RESUMO

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 30wt%, 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/SiO2 ratio, temperature, treatment time at 0.9, 0.8, 1200°C, 60min, respectively. The main crystalline phases of the residues were calcium silicate slag, and an amorphous glass phase appears at a glass addition more than 30wt%. 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.


Assuntos
Tubo de Raio Catódico , Resíduo Eletrônico , Chumbo/isolamento & purificação , Metalurgia/métodos , Reciclagem/métodos , Cálcio/química , Carbono/química , Microscopia Eletrônica de Varredura , Silicatos/química , Temperatura , Termodinâmica , Fatores de Tempo , Difração de Raios X
19.
J Hazard Mater ; 316: 43-51, 2016 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-27209518

RESUMO

In the reduction-melting process, lead can be recovered from cathode ray tube funnel glass (PbO=25wt%); however, resulting glass residues still contain approximately 1-2wt% 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 10g Na2CO3 was added to 20g 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.

20.
J Neurosurg Pediatr ; 17(1): 3-12, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26416669

RESUMO

Injuries to children caused by falling televisions have become more frequent during the last decade. These injuries can be severe and even fatal and are likely to become even more common in the future as TVs increase in size and become more affordable. To formulate guidelines for the prevention of these injuries, the authors systematically reviewed the literature on injuries related to toppling televisions. The authors searched MEDLINE, PubMed, Embase, Scopus, CINAHL (Cumulative Index to Nursing and Allied Health Literature), Cochrane Library, and Google Scholar according to the Cochrane guidelines for all studies involving children 0-18 years of age who were injured by toppled TVs. Factors contributing to injury were categorized using Haddon's Matrix, and the public health approach was used as a framework for developing strategies to prevent these injuries. The vast majority (84%) of the injuries occurred in homes and more than three-fourths were unwitnessed by adult caregivers. The TVs were most commonly large and elevated off the ground. Dressers and other furniture not designed to support TVs were commonly involved in the TV-toppling incident. The case fatality rate varies widely, but almost all deaths reported (96%) were due to brain injuries. Toddlers between the ages of 1 and 3 years most frequently suffer injuries to the head and neck, and they are most likely to suffer severe injuries. Many of these injuries require brain imaging and neurosurgical intervention. Prevention of these injuries will require changes in TV design and legislation as well as increases in public education and awareness. Television-toppling injuries can be easily prevented; however, the rates of injury do not reflect a sufficient level of awareness, nor do they reflect an acceptable effort from an injury prevention perspective.


Assuntos
Acidentes Domésticos/prevenção & controle , Traumatismos Craniocerebrais/prevenção & controle , Televisão , Adolescente , Criança , Pré-Escolar , Traumatismos Craniocerebrais/etiologia , Humanos , Lactente
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