CRT TV Research Articles

A novel MILP model and an improved genetic algorithm for disassembly line balancing and sequence planning with partial destructive mode

Collaborative optimization of disassembly line balancing and disassembly sequence planning can effectively reduce ineffective operation time. Considering the uncertainty of the connection relationship between parts of end-of-life products, a partial destructive disassembly mode based on the disassembly feasibility is introduced. In this study, a mixed integer linear programming (MILP) model of disassembly line balancing and sequence planning (DLBSP) is constructed. The aim is to minimize the number of stations, smoothness index, and energy consumption, and maximize the disassembly profit simultaneously. To obtain high-quality disassembly schemes, a multi-objective improved genetic algorithm is proposed. An encoding and decoding strategy based on problem characteristics is designed to improve the quality of the initial solutions. The feasibility of crossover and mutation operations is ensured by introducing precedence constraints, and a single-point insertion neighborhood strategy is designed to improve the local search ability of the algorithm. Then, the effectiveness of the proposed model and algorithm is verified in a small-scale case, and the performance of the proposed algorithm is better than that of nine meta-heuristics through 22 test cases. Next, the proposed model and algorithm are applied to a real CRT TV disassembly case. It is shown that the new disassembly scheme can reduce two stations, improve smoothness by 99.83%, increase profits by 89.75%, and reduce energy consumption by 24.66% compared to the original scheme. Finally, a DLBSP optimization system is developed, which can reduce the application difficulty of the proposed model and algorithm.

English

Reliable data on e-waste generation is important for environmentally sound management systems. This study models e-waste generation from existing data on electrical electronics imports, consumption and e-waste generation from Nigerian households. Structured questionnaires were used to obtain information on Electrical Electronic Equipment (EEE) use, reuse, and disposal from households in Nigeria households. Data from placed on the market (POM) were obtained from United Nations University (UNU) for five EEE types (TV, DVD player, refrigerator, desktop and laptop) in Nigeria between 1995 and 2019 using the apparent consumption method. A forecast up to 2020 and backcasts to 1980 were made based on these data. The lifetime profile for these five EEEs was modeled using the Weibull distribution function characterized by a time-varying shape parameter and a scale parameter. The POM data from 1980 to 2020 and the lifetime of the selected EEE from households were analyzed and fit into the Weibull lifetime distribution functions. The differences between reuse and non-reuse options show that around 54 million units of DVD players; 106 million units of CRT TV; 22 million units of the refrigerator; 11 million units of laptops and 24 million units of desktop computers would have been delayed from transiting into e-waste stream between 1981 and 2020 through reuse options.   Key words: Electronic waste, electrical electronic equipment, lifetime distribution, re-use repair, recycling, Nigeria.

Debromination process of Br-containing PS of E-wastes and reuse with virgin PS

High Br-containing polystyrene (PS) plastics are generated in large quantities during the dismantling of waste CRT TVs. Debromination and reuse of Br-containing PS plastics is a critical technical challenge. Here, we demonstrate a method for combining alkaline hydrothermal debromination and co-blending granulation to achieve the regeneration of high Br-containing PS plastics. The results show the bromine concentration in PS was reduced from 49,300 mg/kg to 7420 mg/kg and from 169,000 mg/kg to 9340 mg/kg, with a removal efficiency of 84.95% at least. Then, we co-blended the debromination PS products (1 part) with qualified normal PS plastics (9 parts) for granulation. Compared to the qualified normal PS, the physical properties of the co-blended plastics remained stable in terms of the melt index, tensile strength, flexural strength andflexural modulus, which made it have good application prospects. Meanwhile, the Br concentration of co-blended PS plastics were further reduced to less than 1000 mg/kg. In summary, we provide a promising outlook of alkaline hydrothermal and co-blending (1 +9) granulation as an efficient approach for Br-containing PS plastics upgrading recycling. Novelty statementThis study provides a novel method for combining alkaline hydrothermal treatment and co-blending modification granulation process to achieve the upgrading recycling of Br-containing waste plastics. The results show the Br concentration in PS was reduced from 169,013 ppm to 9344 ppm, with a removal efficiency of 94.47%. The debromination PS products (1 part) were blended with qualified normal PS plastics (9 parts) for granulation. Compared to the qualified normal PS, the physical properties of the co-blended plastics remained basically stable, which made it have good application prospects. Also, the reuse of waste plastic can make contribution for the carbon reduction.

Sistem Monitoring Konsumsi Listrik Rumah Tangga dan Perbaikan Faktor Daya dengan Modul GSM Berbasis Mikrokontroller ATmega32

Power factor default is 0.85. if the power factor is less then 085, it will cause a loss to the user. In addition, the low value of the power factor will cause the maximum power capacity not to be used. Therefore designed a monitoring tool and improvement of power factors in household electricity consumption via SMS. This tool is constructed using a combination of current sensor, voltage sensor to determine the work of monitoring system for the use of current, voltage, power, and the value of power factor in household electricity consumption. In addition, bank capacitors are used to repair on increase the value of power factors and the GSM SIM 800L module is used to sending SMS from the system to the user so that the use of household electricity consumption can be monitored ini real time. Testing is done at home using household loads, namely blender, mixers, CRT TV, refrigerator and washing machines. The test results obtained are the percentage increase in the value of the average power factor of 27.12 % and after an improvement in the power factor using a capacitor bank can save costs by about 22 % and able to monitor by SMS so this shows that this tool is able to monitor and improve the power factor efficiently

Polybrominated diphenyl ethers in plastic waste of electrical and electronic equipment: a case study in Belarus.

Plastic waste of electrical and electronic equipment (WEEE) can contain polybrominated diphenyl ethers (PBDEs) that have been used as fire retardants for a long time. PBDEs were listed in the Stockholm Convention as persistent organic pollutants, so PBDE-containing plastic waste should be separated and disposed of in an ecologically sound manner. In the article, the results of bromine and PBDE content in plastic samples of WEEE collected in Belarus are presented. The screening method for bromine identification and HRGC/HRMS for PBDE identification were applied. It is shown that bromine is present in 43% of the 111 studied samples. Most often, Br-containing plastic was found in CRT monitor, CRT TVs and LCD monitor (about 50%), printers (35%), and LCD TVs (25%). PBDEs were revealed in 12 Br-containing samples, representing TVs, monitors, and printers. The sum of ∑10PBDEs varied from 6.6 to 21,000μg/kg. BDE-209 dominated in 9 samples (75% of cases); BDE-183, in two; and BDE-47 and BDE-99, in one sample. Based on the low content of PBDEs in the plastic, year of equipment production, and year of restriction of PBDEs applied in the countries-manufacturers, it was concluded that the presence of PBDEs in plastic is a consequence of contaminated waste recycling. Despite the relatively low concentrations of PBDEs (below the limit values established by the Stockholm and Basel conventions for POP wastes), further research is necessary with an extension of the list of analyzed types of equipment and identification of other brominated flame retardants.

Characterization of brominated flame retardants from e-waste components in China

Many studies show that high levels of many toxic metals and persistent and bio-accumulative chemicals have been found in electronic waste (e-waste) dismantling sites and their surrounding environmental media. Both flame-retardant plastic housing materials and printed circuit boards (PCBs) could be the major contributors. However, relatively little work has focused on the use or content of toxic substances and their changing in scrap housing materials and PCBs from home appliances. This study evaluated the existence of brominated flame retardants (BFRs, including polybrominated diphenyl ethers (PBDEs) and Tetrabromobisphenol-A (TBBPA)) in housing plastics and PCBs from home appliances collected from various e-waste recyclers in China. These were then analyzed for the potential migration of BFRs from the e-waste components into their recycled products. The results show that both PBDEs and TBBPA were found with high level in most of e-waste samples, indicating that the widespread use of BFRs in home appliances are entering into the end-of-life stage. For the plastics samples, CRT TVs and LCD monitors should be given priority for the control of BFRs. Regarding PBDEs, the dominant congeners of BDE-209 in the plastics samples contributed 90.72–93.54% to the total concentrations of PBDEs, yet there are large variations for PCBs samples: BDE-28, -47, -99, and -153 were also important congeners compositions, except for BDE-209. Compared with previous studies, the BFRs concentrations in current Chinese e-waste are trending to decline. This study also found that BFRs in housing plastics and PCBs will be transferred into the recycled products with other purpose use, and the new products could have highly enriched capacities for BFRs. The obtained results could be helpful to manage e-waste and their components properly in order to minimize associated environmental and health risks of BFRs, particularly for their further reuse.

Modelling in-use stocks and spatial distributions of household electronic devices and their contained metals based on household survey data

Waste electrical and electronic equipment (WEEE) contains a significant amount of critical and precious metals. Recovery of these metal resources is important for both environmental and economic reasons. However, the potential for metal recovery from the distributed resource of used electronic devices in households has not been well understood. This paper explores such potential through modelling in-use stocks and spatial distributions of metal resources in household electronic devices based on household survey data, using Australia as a case study. We focused on ten categories of electronic devices: smart mobile phones, plain mobile phones, tablets, laptops, desktops, flat screen TVs, CRT TVs, monitors, hand held music players and game devices. Regression models were built using demographic variables as predictors to estimate the amount of electronic devices currently in use in households, and the bottom-up approach was employed to estimate the stocks of forty three metals contained in the devices. A set of maps were produced to show the estimated distribution of the resource of in-use household electronic devices and specific metals of interest contained in these devices. We find that some metals such as Platinum-group elements have more stocks in Australian household devices than the potential stocks in Australian mineral deposits. There is some intrinsic resource value contained in Australian household electronic goods, and interest in recovery of these particular metals might come sooner than for others.

Product screening for sources of halogenated flame retardants in Canadian house and office dust

Human exposure to halogenated flame retardants (HFRs) such as polybrominated diphenyl ethers (PBDEs) and their replacements, can be related to exposure to indoor dust and direct contact with HFR-containing products. This study aimed to identify electronic products that contributed to HFRs measured in indoor dust and to develop a screening method for identifying HFRs in hard polymer products. Concentrations of 10 PBDEs and 12 halogenated replacements in dust and surface wipe samples of hard polymer casings of electronic products plus Br in the surfaces of those casing measured using X-ray fluorescence (XRF) were analyzed from 35 homes and 10 offices in Toronto (ON, Canada). HFR concentrations in dust and product wipes were positively correlated. Thus, we hypothesize that electronic products with the highest HFR concentrations contribute the most to concentrations in dust, regardless of the volatility of the HFR. Abundant HFRs in dust and product wipes were PBDEs (BDE-47, 99, 100, 153, 154, 183, 209), TDCPP, DBDPE, EH-TBB and BEHTBP. Older CRT TVs had the highest concentration of BDE-209 of all products tested. This was followed by higher concentrations of HFRs in PCs, Audio/Video (A/V) devices, small household appliances (HHAs) and flat screen TVs. The removal of HFRs from polymer surfaces using wipes supports concerns that HFRs could be transferred from these surfaces to hands as a result of direct contact with HFR-containing products. Surface wipe testing shows promise for screening additive HFRs. In comparison, the Br-content obtained using a handheld XRF analyzer did not correspond to concentrations obtained from surface wipe testing.

Out with the old, out with the new – The effect of transitions in TVs and monitors technology on consumption and WEEE generation in Sweden 1996–2014

The recycling of Waste Electrical and Electronic Equipment (WEEE) is important due to its content of valuable and hazardous compounds. This study investigates the case of the recent technology change within television sets (TVs) and monitors, its impact on the generation of WEEE, and the implications for the recycling industry. In particular, material flow analysis for the time series of 1996–2014 for TVs and monitors by type of technology (CRT, Plasma and LCD) in physical units is combined with empirical data on product lifespans. The number of consumed TVs and monitors has grown exponentially. As a result, despite a 3-fold reduction in the weight of the products, the weight of the corresponding WEEE is also growing exponentially. Out with the old, out with the new – a peak in WEEE from both CRT and flat-screen displays is expected during 2014–2020, due to the simultaneous obsolesce of the last wave of CRT products and the short-lived flat-screen products that substituted the CRTs. The lifespans of LCD and LED TVs were found to be three times shorter than of the CRT TVs, with many TVs discarded while still functional. This is the consequence of two events – replacement of the CRT TVs in combination with lifestyle purchases of TVs, i.e. the premature replacement of flat-screen displays with new sets with extra-large screens and/or new features. The throughput of TVs and monitors consumed has been estimated annually from 2014 until 2040, by quantity and type of device, as well as by component and material type. The annual economic value of the corresponding secondary materials, by material type, has also been estimated. The point in time when the final disposal of CRT products is likely to take place has been identified and should be noted by the recycling industry. Among the important contributions of this study to the accounting and predicting of amounts and types of WEEE are the lifespan distributions, size and weight distributions, and material composition for TVs and monitors of different technology. Directions for method application in other countries are given.

The use of air separation in recycling CRT TV sets

The aim of this paper is to examine the possibility of use of air separation in recycling CRT TV sets and determine the effect of operating variables of separators. Eight CRT TV sets were collected and after manual disassembly, parts of CRT TV sets were sorted into four fractions taking into account their properties. The subject of this research was the fraction consisting of yokes of a cathode tube, cables, connectors and wires. Testing samples were obtained by manual disassembly, shredding and sieving, after which the separation on the model of a cross-flow gravity air separator with horizontal flow was carried out. Four grain sizes, 4/2mm, 2/1mm, 1/0.5mm and −0.5mm, were tested on the separator. Testing was carried out according to the central composite design for three factors: splitter height, air velocity and feed position. The evaluation of results was carried out by the analysis of two parameters: concentrate grade and recovery. The obtained values of the concentrate grade varied from 45.9% for the smallest grain size of −0.5mm to 89.4% for the grain size of 1/0.5mm while recovery was very high, mostly over 99%. The highest increase of metal content in the concentrate of 21.1% was recorded for the smallest grain size of −0.5%. The Analysis of Variance showed that the splitter height and feed position have the strongest effect on the concentrate grade.

Application of a Cost–benefit Analysis Model to the Use of Flame Retardants

For the past 30 to 40 years, regulation of the environment has been governed by Environmental Protection Agencies worldwide. During this time we have learned that regulations have significant costs, not just benefits, and that analysis of the cost and benefit of proposed rules is an indispensable component of responsible regulation. Despite present-day recognition of the importance of cost benefit analysis prior to enacting regulations, this is still a controversial issue, especially in light of moral issues such as establishing the value of a statistical life and whether net benefit is always necessary before invoking regulation. In this paper, real and perceived risks associated with exposure to flame retardants and to fires are discussed and a monetary value placed on the costs and benefits associated with these chemicals. The model developed has been called the Fire-CBA model and is applied to a case study comparing CRT TV sets where one model contains flame retardant in the outer enclosure and the other does not. In all, a total of 9 scenarios were tested for the TV set application of the Fire-CBA model. In all cases, the benefits of a high level of fire performance in a TV set far outweigh the costs associated with obtaining that high level of fire safety. The net benefit is a function of the choices made in the various scenarios but ranges from US$49 to 1073 million per year. The various scenarios were chosen to illustrate the significance of the parameters included in the study, as the specific value chosen for each parameter can vary depending on the assumptions made in the model.

Recovery of Y and Eu from Waste Phosphors of CRT TVs and the Preparation of Yttrium Europium Oxide

Yttrium (Y) and Europium (Eu) were recovered from waste phosphors of TV screens via several processes, including roasting waste phosphors with ammonia chloride, dissolving yttrium chloride and europium chloride with water from roasted waste phosphors, purification with sodium sulfide, precipitating in the presence oxalic acid and calcining at high temperature. The optimal conditions for roasting was investigated, and it was found that when 1 g sample reacts with 8 g ammonia chloride, the recovery rate of Y and Eu can be 92.12% and 90.38% after 30min reaction at 90°C, respectively. Moreover, the optimal pH value for recovering Y and Eu was also investigated. It was found that at pH=1, the stoichiometric ratio of B/A (A: S2-, B: Zn2+, etc) is 1:1, the stoichiometric ratio of B/A (A: Y3+, B: C2O42-, etc) is 2:1, the content of Y and Eu can be reached 98.10% and 96.30%, respectively. And yttrium europium oxide was finally synthesized, which produce the red light when the excitation wavelength was 242 nm.

Tripartite dynamic competition and equilibrium analysis on global television market

This study intends to investigate the tripartite competition among CRT, LCD and PDP TV by means of the quarterly shipments of 30- to 45-in. TV. The Lotka–Volterra competition diffusion model has been adopted to conduct the empirical analysis with the Lyapunov function to carry out equilibrium and stability. The results indicate that adopting this model can lead to good performance. The price dropping of LCD TV is greater than that of CRT and PDP TV. The severe dropping in the price of LCD TV leads to its higher growth rates. With respect to the equilibrium and stability analysis, PDP and LCD TV will coexist in the TV market and reach a stable equilibrium, while CRT TV will disappear from the 30- to 45 in. TV market.

RoHS regulated Substances in Mixed Plastics from Waste Electrical and Electronic Equipment

The disposal and recovery of plastics from waste electrical and electronic equipment (WEEE) are of considerable importance, both from an environmental and an economic perspective. This paper presents the results of a study investigating current concentrations of hazardous substances in mixed plastics from WEEE and their implications for an environmentally sound recovery. The study included 53 sampling campaigns for mixed plastics from WEEE. The samples were analyzed with regard to heavy metals (cadmium, chromium, mercury, and lead) and flame retardants (PentaBDE, OctaBDE, DecaBDE, DecaBB) regulated in the RoHS Directive. Besides these substances, other brominated flame retardants known to occur in electronics (HBCD, TBBPA) as well as the total bromine and phosphorus contents were considered. Results show that no mixed plastics fraction from WEEE is completely free from substances regulated in the RoHS Directive. The lowest number and average concentrations were found in flat screen monitors. The highest concentrations were found in mixed plastics from CRT monitors and TVs. Mixed plastics fractions with high average concentrations of heavy metals originate from the treatment of small household appliances (cadmium), ICT equipment (lead), and consumer equipment (lead). Mixed plastics fractions with high average concentrations of brominated flame retardants mainly originate from the treatment of small household appliances for high temperature applications (DecaBDE), CRT monitors (OctaBDE and DecaBDE) and consumer equipment (DecaBDE), in particular CRT TVs (DecaBDE). To avoid a dissipation of hazardous substances into plastics and the environment, it is recommended that mixed plastics from WEEE are subject to a strict quality management.

A preliminary categorization of end-of-life electrical and electronic equipment as secondary metal resources

End-of-life electrical and electronic equipment (EEE) has recently received attention as a secondary source of metals. This study examined characteristics of end-of-life EEE as secondary metal resources to consider efficient collection and metal recovery systems according to the specific metals and types of EEE. We constructed an analogy between natural resource development and metal recovery from end-of-life EEE and found that metal content and total annual amount of metal contained in each type of end-of-life EEE should be considered in secondary resource development, as well as the collectability of the end-of-life products. We then categorized 21 EEE types into five groups and discussed their potential as secondary metal resources. Refrigerators, washing machines, air conditioners, and CRT TVs were evaluated as the most important sources of common metals, and personal computers, mobile phones, and video games were evaluated as the most important sources of precious metals. Several types of small digital equipment were also identified as important sources of precious metals; however, mid-size information and communication technology (ICT) equipment (e.g., printers and fax machines) and audio/video equipment were shown to be more important as a source of a variety of less common metals. The physical collectability of each type of EEE was roughly characterized by unit size and number of end-of-life products generated annually. Current collection systems in Japan were examined and potentially appropriate collection methods were suggested for equipment types that currently have no specific collection systems in Japan, particularly for video games, notebook computers, and mid-size ICT and audio/video equipment.

The interaction of the market competition between LCD TV and PDP TV

The size of CRT TV has always been limited by their bulk. However, the introduction of flat plane display TV has led to much larger screens, new rounds of technological innovation, largescale investment and an increasing share of the consumer market. Moreover, this development has spurred competition for market share between LCD TV and PDP TV. This study intends to investigate the dynamic competitive relationship between PDP TV and LCD TV by means of the quarterly shipment of TV. The Lotka–Volterra competition diffusion model has been adopted to conduct the empirical analysis, with the Lyapunov function used to carry out equilibrium and stability analysis. The result illustrates that there is good fitting performance in adopting this model. In the competitive relationship we can regard the LCD TV as a prey and the PDP TV as the predator. Nevertheless, the possibility of dropping the price of LCD TV is an advantage, which can be noted in the higher growth rate compared to PDP TV. With respect to the equilibrium and stability analysis, 30- to 39-in. and 40- to 49-in. PDP TV will not disappear from the market, but will instead reach stable equilibrium with LCD TV.

A technology replacement model with variable market potential — An empirical study of CRT and LCD TV

The rapidly changing economic environment and increasingly fierce competition indicate that companies must innovate in both their products and marketing strategies if they are to continue to flourish. Specifically, the ability to accurately predict the demand for products is crucial when firms decide to allocate their resources, especially in the fast moving high technology industries, where there is very high investment in R&D and production facilities. This study establishes a forecast model for technology replacement based on the diffusion model with population growth used for the variable market potential. The proposed model is then applied to investigate the CRT and LCD TV market. The results suggest that the new model is more accurate than the constant market potential model in fitting and forecasting performance. Consumers who purchase a TV for the first time are likely more attracted to LCD TV rather than CRT TV. As for those individuals who already own a CRT TV, the attraction is not strong enough to encourage them to replace their current CRT TV with a new LCD TV. Moreover, it is noted that the falling price of LCD TV is an essential factor in encouraging purchases.

Preparation of foamed glasses from CRT TV glass by means of hydrothermal hot-pressing technique

The feasibility to prepare foamed glass specimens by using waste TV monitor (panel) glass as starting material under hydrothermal hot-pressing (HHP) conditions, followed by a conventional heating of the compact, was investigated. Hydrothermally hot pressed glass compacts were preliminarily prepared at a constant temperature of 200 °C, with a loading pressure of 20 MPa and two different water contents (5 and 10 wt%), for reaction intervals between 0.5 and 2 h, employing a glass particle size <38 μm. After the powder densification stage, firing of the compacted disk glass was conducted over a temperature range of 650–850 °C for 1 h. Microstructural observations conducted by SEM showed the formation of a new glass phase which incorporates water, this phase was formed during the glass densification stage at 200 °C for 2 h, with a water content of 10 wt%. The lowest apparent density achieved on these glass compacts heated at 700 °C for 1 h was 0.36 g/cm 3. This value is similar to that of other foamed glasses that have close cell network and low thermal conductivity (0.0021 W/cm/°C).

다양한 디스플레이 기기의 주관적 화질 상관도 비교

최근 국제전기통신연합은 몇몇 객관적 화질평가 모델을 국제 표준으로 채택하였다. 채택된 화질평가 모델은 방송용 CRT 모니터를 통해 출력되는 디지털 비디오의 품질을 측정하는데 적합하도록 개발되었다. 본 논문에서는 객관적 품질평가 모델이 방송용 CRT 뿐만 아니라 일반적인 CRT, PDP, LCD 등의 디스플레이 기기에 적용이 가능한지 검토하기 위하여 주관적 실험을 시행하였다. 다양한 디스플레이 기기를 대상으로 주관적 품질평가를 시행한 결과 각각의 디스플레이 기기 사이에 비교적 높은 상관관계가 존재하였다. 이는 표준으로 채택된 화질평가 모델이 주어진 주관적 평가 조건하에서 각각의 디스플레이 기기에 적용될 수 있다는 것을 보여준다. Recently, International Telecommunication Union approved several methods for objective video quality measurements to be included in international standards. These methods are mainly developed to measure quality of digital video on professional CRT monitors. In this paper, we performed subjective tests in order to examine the applicability of the standard quality assessment methods for different display monitors such as common CRT, PDP, and LCD TV monitors as well as professional CRT monitors. Subjective testing on different display monitors shows that there exist relatively high correlations between the various display monitors, which indicates the standard quality assessment methods can be used on the display monitors under the given conditions of subjective duality assessment.

26.2: Comparison of Motion Blur Measurement in LCD

AbstractCompared to traditional CRT TV, LC TV has the shortcoming of motion blur. There are two causes for LCD motion blur: (1) LCD slow temporal response and (2) LCD backlight is always‐on (Hold effect). Motion blur can be characterized with the motion picture response time metric (MPRT). MPRT of a display can be measured spatially using a commercial MPRT instrument, but it is very expensive and difficult to use. In our previous papers, we modeled LCD motion blur through it temporal point spread function (temporal PSF) of an LCD device so that the LCD temporal PSF can uniquely determine the motion blur. The MPRT can thus be measured from the temporal measurement, which is much easier than the spatial tracking camera approach. In this paper, we compared the measured motion blur using both the spatial tracking camera approach and the temporal response approach at various backlight flashing widths. The temporal method can potentially replace expensive MPRT instrument.