nitrogen application for lcd displays factory
Since its initial communalization in the 1990s, active matrix thin-film-transistor (TFT) displays have become an essential and indispensable part of modern living. They are much more than just televisions and smartphones; they are the primary communication and information portals for our day-to- day life: watches (wearables), appliances, advertising, signage, automobiles and more.
However, there are technology drivers and manufacturing challenges that differentiate the two. For semiconductor device manufacturing, there are technology limitations in making the device increasingly smaller. For display manufacturing, the challenge is primarily maintaining the uniformity of glass as consumers drive the demand for larger and thinner displays.
While semiconductor wafer size has maxed because of the challenges of making smaller features uniformly across the surface of the wafer, the size of the display mother glass has grown from 0.1m x 0.1m with 1.1mm thickness to 3m x 3m with 0.5mm thickness over the past 20 years due to consumer demands for larger, lighter, and more cost-effective devices.
As the display mother glass area gets bigger and bigger,so does the equipment used in the display manufacturing process and the volume of gases required. In addition, the consumer’s desire for a better viewing experience such as more vivid color, higher resolution, and lower power consumption has also driven display manufacturers to develop and commercialize active matrix organic light emitting displays (AMOLED).
In general, there are two types of displays in the market today: active matrix liquid crystal display (AMLCD) and AMOLED. In its simplicity, the fundamental components required to make up the display are the same for AMLCD and AMOLED. There are four layers of a display device (FIGURE 1): a light source, switches that are the thin-film-transistor and where the gases are mainly used, a shutter to control the color selection, and the RGB (red, green, blue) color filter.
The thin-film-transistors used for display are 2D transitional transistors, which are similar to bulk CMOS before FinFET. For the active matrix display, there is one transistor for each pixel to drive the individual RGB within the pixel. As the resolution of the display grows, the transistor size also reduces, but not to the sub-micron scale of semiconductor devices. For the 325 PPI density, the transistor size is approximately 0.0001 mm2 and for the 4K TV with 80 PPI density, the transistor size is approximately 0.001 mm2.
Technology trends TFT-LCD (thin-film-transistor liquid-crystal display) is the baseline technology. MO / White OLED (organic light emitting diode) is used for larger screens. LTPS / AMOLED is used for small / medium screens. The challenges for OLED are the effect of < 1 micron particles on yield, much higher cost compared to a-Si due to increased mask steps, and moisture impact to yield for the OLED step.
Mobility limitation (FIGURE 2) is one of the key reasons for the shift to MO and LTPS to enable better viewing experience from higher resolution, etc.
The challenge to MO is the oxidation after IGZO metalization / moisture prevention after OLED step, which decreases yield. A large volume of N2O (nitrous oxide) is required for manufacturing, which means a shift in the traditional supply mode might need to be considered.
Although AMLCD displays are still dominant in the market today, AMOLED displays are growing quickly. Currently about 25% of smartphones are made with AMOLED displays and this is expected to grow to ~40% by 2021. OLED televisions are also growing rapidly, enjoying double digit growth rate year over year. Based on IHS data, the revenue for display panels with AMOLED technol- ogies is expected to have a CAGR of 18.9% in the next five years while the AMLCD display revenue will have a -2.8% CAGR for the same period with the total display panel revenue CAGR of 2.5%. With the rapid growth of AMOLED display panels, the panel makers have accel- erated their investment in the equipment to produce AMOLED panels.
There are three types of thin-film-transistor devices for display: amorphous silicon (a-Si), low temperature polysilicon (LTPS), and metal oxide (MO), also known as transparent amorphous oxide semiconductor (TAOS). AMLCD panels typically use a-Si for lower-resolution displays and TVs while high-resolution displays use LTPS transistors, but this use is mainly limited to small and medium displays due to its higher costs and scalability limitations. AMOLED panels use LTPS and MO transistors where MO devices are typically used for TV and large displays (FIGURE 3).
This shift in technology also requires a change in the gases used in production of AMOLED panels as compared with the AMLCD panels. As shown in FIGURE 4, display manufacturing today uses a wide variety of gases.
These gases can be categorized into two types: Electronic Specialty gases (ESGs) and Electronic Bulk gases (EBGs) (FIGURE 5). Electronic Specialty gases such as silane, nitrogen trifluoride, fluorine (on-site generation), sulfur hexafluoride, ammonia, and phosphine mixtures make up 52% of the gases used in the manufacture of the displays while the Electronic Bulk gases–nitrogen, hydrogen, helium, oxygen, carbon dioxide, and argon – make up the remaining 48% of the gases used in the display manufacturing.
The key ga susage driver in the manufacturing of displays is PECVD (plasma-enhanced chemical vapor deposition), which accounts for 75% of the ESG spending, while dry etch is driving helium usage. LTPS and MO transistor production is driving nitrous oxide usage. The ESG usage for MO transistor production differs from what is shown in FIGURE 4: nitrous oxide makes up 63% of gas spend, nitrogen trifluoride 26%, silane 7%, and sulfur hexafluoride and ammonia together around 4%. Laser gases are used not only for lithography, but also for excimer laser annealing application in LTPS.
Silane: SiH4 is one of the most critical molecules in display manufacturing. It is used in conjunction with ammonia (NH3) to create the silicon nitride layer for a-Si transistor, with nitrogen (N2) to form the pre excimer laser anneal a-Si for the LTPS transistor, or with nitrous oxide (N2O) to form the silicon oxide layer of MO transistor.
Nitrogen trifluoride: NF3 is the single largest electronic material from spend and volume standpoint for a-Si and LTPS display production while being surpassed by N2O for MO production. NF3 is used for cleaning the PECVD chambers. This gas requires scalability to get the cost advantage necessary for the highly competitive market.
Nitrous oxide: Used in both LTPS and MO display production, N2O has surpassed NF3 to become the largest electronic material from spend and volume standpoint for MO production. N2O is a regional and localized product due to its low cost, making long supply chains with high logistic costs unfeasible. Averaging approximately 2 kg per 5.5 m2 of mother glass area, it requires around 240 tons per month for a typical 120K per month capacity generation 8.5 MO display production. The largest N2O compressed gas trailer can only deliver six tons of N2O each time and thus it becomes both costly and risky
Nitrogen: For a typical large display fab, N2 demand can be as high as 50,000 Nm3/hour, so an on-site generator, such as the Linde SPECTRA-N® 50,000, is a cost-effective solution that has the added benefit of an 8% reduction in CO2 (carbon dioxide) footprint over conventional nitrogen plants.
Helium: H2 is used for cooling the glass during and after processing. Manufacturers are looking at ways to decrease the usage of helium because of cost and availability issues due it being a non-renewable gas.
N2 On-site generators: Nitrogen is the largest consumed gas at the fab, and is required to be available before the first tools are brought to the fab. Like major semiconductor fabs, large display fabs require very large amounts of nitrogen, which can only be economically supplied by on-site plants.
Individual packages: Specialty gases are supplied in individual packages. For higher volume materials like silane and nitrogen trifluoride, these can be supplied in large ISO packages holding up to 10 tons. Materials with smaller requirements are packaged in standard gas cylinders.
In-fab distribution: Gas supply does not end with the delivery or production of the material of the fab. Rather, the materials are further regulated with additional filtration, purification, and on-line analysis before delivery to individual production tools.
The consumer demand for displays that offer increas- ingly vivid color, higher resolution, and lower power consumption will challenge display makers to step up the technologies they employ and to develop newer displays such as flexible and transparent displays. The transistors to support these new displays will either be LTPS and / or MO, which means the gases currently being used in these processes will continue to grow. Considering the current a-Si display production, the gas consumption per area of the glass will increase by 25% for LTPS and ~ 50% for MO productions.
To facilitate these increasing demands, display manufacturers must partner with gas suppliers to identify which can meet their technology needs, globally source electronic materials to provide customers with stable and cost- effective gas solutions, develop local sources of electronic materials, improve productivity, reduce carbon footprint, and increase energy efficiency through on-site gas plants. This is particularly true for the burgeoning China display manufacturing market, which will benefit from investing in on-site bulk gas plants and collaboration with global materials suppliers with local production facilities for high-purity gas and chemical manufacturing.
the need for additional fertilization. Just like GreenSeekerTM, SPAD is suitable for use in all weather conditions, but unlike GreenSeekerTM, SPAD can be used on larger trees, shrubs, and vines.
Nitrogen trifluoride (NF3) is an inorganic, colorless, non-flammable, toxic gas with a slightly musty odor. It is primarily used to remove silicon and silicon-compounds during the manufacturing of semiconductor devices such as LCD displays, some thin-film solar cells, and other microelectronics. Unlike the fluorinated carbons, Nitrogen Trifluoride is easy to decompose due to relatively low bond energy in N—F bond, and therefore can be a fluorine source.
NF3 has the ability to act as a stable fluorinating agent and has a wide application scope in high-energy laser at dry etching in semiconductor production as a filling gas in lamps to prolong their durability and increase brightness, as well as a detergent gas in CVD apparatus. For all these reasons, nitrogen trifluoride is increasingly used in the electronics industry, primarily for the etching of microcircuits, and for manufacturing of liquid crystal flat panel displays and thin film PV cells.
Once NF3 is released into the atmosphere, it circulates from the surface to the stratosphere hundreds of times before it is destroyed by solar ultraviolet radiation. It is nearly chemically inert in the atmosphere, and the average lifetime of an NF3 molecule in the atmosphere is about 550 years.
The market for LCD displays is undergoing rapid growth centered on notebook computers, cellular phones and LCD televisions. LCD televisions, in particular, are becoming larger and less expensive thanks to technological innovations and the ramping up of mass production. With the appearance of 8K TV sets etc, the consumer appetite for LCD televisions is growing, so demand is expected to continue to expand going forward. CoorsTek provides a variety of materials that are essential to the LCD display manufacturing process and help raise production efficiency.
CoorsTek has developed and supplies a variety of fine ceramic products that are needed to manufacture semiconductors, including quartz glass, carbon products, and silicon carbide products. The purification, processing and evaluation technologies we have developed out of this are highly competitive when applied to the manufacturing process for LCD displays as well, which is quite similar.
We provide a diverse array of materials for the manufacturing processes to help rationalize and streamline LCD production. Products that have earned a strong reputation with our customers include synthetic quartz photomask substrates, a strategic product that improves the exposure precision of micro-circuitry, vacuum breaking filters and silicon carbide materials sintered under atmospheric pressure.
As LCD displays have become larger in recent years, the glass substrates that make up the displays have been growing in stride. Around 2000, the 730 x 920 mm size, called the fourth generation, was mainstream. By 2005, mass production had been initiated for the seventh generation (1,870 x 2,200 mm) and, in 2006, mass production began on 2,160 x 2,400 mm displays, the eighth generation, as the move to larger sizes has accelerated.
In conjunction with this evolution, greater precision and proprietary expertise has come to be required for materials production as well. We already have a system in place to accommodate growth in the size of photomask substrates thanks to our synthetic quartz purification and polishing technologies and unique know-how in the area of mass production, so are ready to meet the rising demand to come.
These current control filters for vacuum breaking*1 use the pressure buffering effects possessed by porous ceramics. They render unnecessary the slow vents*2 that used to be required for vacuum breaking and are effective in reducing particles and preventing particle outbreaks. This product is used not only in the deposition step, but also in the exposure and etching steps.
This ceramic material is next in hardness to diamonds while also being lightweight. It is highly regarded as a material for ultra-flat, lightweight platforms that do not bend or warp, making possible accurate exposure.
This product is used as a roller to convey TFT array substrates. Using highly pure silica glass serves to prevent metallic contamination and damage from particles. For this reason, it is also used for conveyance in the manufacture of sheet glass for flat panel displays (FPD).
Quartz chambers are used as batch furnaces inside heat treatment systems for thin film transistor (TFT) array substrates, which are main type of LCD display using the active matrix method. Compared to metal, quartz is capable of restricting the occurrence of particles to an absolute minimum and it helps prevent metallic contamination.
The amount of pollutants produced during manufacturing processes of TFT-LCD (thin-film transistor liquid crystal display) substantially increases due to an increasing production of the opto-electronic industry in Taiwan. The total amount of wastewater from TFT-LCD manufacturing plants is expected to exceed 200,000 CMD in the near future. Typically, organic solvents used in TFT-LCD manufacturing processes account for more than 33% of the total TFT-LCD wastewater. The main components of these organic solvents are composed of the stripper (dimethyl sulphoxide (DMSO) and monoethanolamine (MEA)), developer (tetra-methyl ammonium hydroxide (TMAH)) and chelating agents. These compounds are recognized as non-or slow-biodegradable organic compounds and little information is available regarding their biological treatability. In this study, the performance of an A/O SBR (anoxic/oxic sequencing batch reactor) treating synthetic TFT-LCD wastewater was evaluated. The long-term experimental results indicated that the A/O SBR was able to achieve stable and satisfactory removal performance for DMSO, MEA and TMAH at influent concentrations of 430, 800, and 190 mg/L, respectively. The removal efficiencies for all three compounds examined were more than 99%. In addition, batch tests were conducted to study the degradation kinetics of DMSO, MEA, and TMAH under aerobic, anoxic, and anaerobic conditions, respectively. The organic substrate of batch tests conducted included 400 mg/L of DMSO, 250 mg/L of MEA, and 120 mg/L of TMAH. For DMSO, specific DMSO degradation rates under aerobic and anoxic conditions were both lower than 4 mg DMSO/g VSS-hr. Under anaerobic conditions, the specific DMSO degradation rate was estimated to be 14 mg DMSO/g VSS-hr, which was much higher than those obtained under aerobic and anoxic conditions. The optimum specific MEA and TMAH degradation rates were obtained under aerobic conditions with values of 26.5 mg MEA/g VSS-hr and 17.3 mg TMAH/g VSS
The amount of pollutants produced during manufacturing processes of thin-film transistor liquid crystal display (TFT-LCD) substantially increases due to an increasing production of the opto-electronic industry in Taiwan. This study presents the treatment performance of one aerobic and one anoxic/oxic (A/O) sequencing batch reactors (SBRs) treating synthetic TFT-LCD wastewater containing dimethyl sulfoxide (DMSO), monoethanolamine (MEA), and tetra-methyl ammonium hydroxide (TMAH). The long-term monitoring results for the aerobic and A/O SBRs demonstrate that stable biodegradation of DMSO, MEA, and TMAH can be achieved without any considerably adverse impacts. The ammonium released during MEA and TMAH degradation can also be completely oxidized to nitrate through nitrification in both SBRs. Batch studies on biodegradation rates for DMSO, MEA, and TMAH under anaerobic, anoxic, and aerobic conditions indicate that effective MEA degradation can be easily achieved under all three conditions examined, while efficient DMSO and TMAH degradation can be attained only under anaerobic and aerobic conditions, respectively. The potential odor problem caused by the formation of malodorous dimethyl sulfide from DMSO degradation under anaerobic conditions, however, requires insightful consideration in treating DMSO-containing wastewater. Copyright (c) 2010 Elsevier Ltd. All rights reserved.
Fluorinated greenhouse gases (F-GHGs) are among the most potent and persistent greenhouse gases contributing to global climate change. Learn about the manufacturing processes which release F-GHGs, and how LCD suppliers are working to reduce emissions.
This research is mainly to explore the treatment capacity for TFT-LCD industrial wastewater recycling by the processes combined with membrane bioreactor (MBR), reverse osmosis (RO) and ozone(O3). The organic wastewater from the TFT-LCD industry was selected as the target. MBR, RO and ozone plants were established for evaluation. An MBR plant consisted of a 2-stage anoxic/aerobic bioreactor and an immersed UF membrane unit was employed. The effluent of MBR was conducted into the RO system then into the ozone system. The RO system consisted of a spiral membrane in the vessel. One bubble column, 75 cm high and diameter 5 cm, were used as the ozonation reactor. On the bottom of ozonation reactor is a porous diffuser for releasing gas, with an aperture of 100 microm (0.1 cm). Over the whole experimental period, the MBR process achieved a satisfactory organic removal. The COD could be removed with an average of over 98.5%. For the TOC item, the average removal efficiency was 97.4%. The stable effluent quality and satisfactory removal performance were ensured by the efficient interception performance of an immersed UF membrane device incorporated with the biological reactor. Moreover, the MBR effluent did not contain any suspended solids and the SDI value was under 3. After the treatment of RO, excellent water quality was found. The water quality of permeate was under 5 mg/I, 2 mg/l and 50 micros/cm for COD, TOC and conductivity respectively. The treated water can be recycled and reused for the cooling tower make-up water or other purposes. After the treatment of ozone, the treated water quality was under 5 mg/l and 0.852 mg/l for COD and TOC respectively. The test results of MBR, MBR/RO and MBR/RO/ozone processes were compared as possible appropriate treatment technologies applied in TFT-LCD industrial wastewater reuse and recycling.
In TFT-LCD industry, water plays a variety of roles as a cleaning agent and reaction solvent. As good quality water is increasingly a scarce resource and wastewater treatment costs rises, the once-through use of industrial water is becoming uneconomical and environmentally unacceptable. Instead, recycling of TFT-LCD industrial wastewater is become more attractive from both an economic and environmental perspective. This research is mainly to explore the capacity of TFT-LCD industrial wastewater recycling by the process combined with membrane bioreactor and reverse osmosis processes. Over the whole experimental period, the MBR process achieved a satisfactory organic removal. The COD could be removed with an average of over 97.3%. For TOC and BOD5 items, the average removal efficiencies were 97.8 and 99.4% respectively. The stable effluent quality and satisfactory removal performance were ensured by the efficient interception performance of the UF membrane device incorporated with biological reactor. Moreover, the MBR effluent did not contain any suspended solids and the SDI value was under 3. After treatment of RO, excellent water quality of permeate were under 5 mg/l, 2.5 mg/l and 150 micros/cm for COD, TOC and conductivity respectively. The treated water can be recycled for the cooling tower make-up water or other purposes.
This study evaluated TMAH biodegradation under methanogenic conditions. Under methanogenic conditions, a sludge from a full-scale UASB treating TFT-LCD wastewater was able to degrade 2,000 mg/L of TMAH within 10 h and attained a specific degradation rate of 19.2 mgTMAH/gVSS-h. Furthermore, several chemicals including some surfactants, DMSO, and sulfate were examined for their potential inhibitory effects on TMAH biodegradation under methanogenic conditions. The results indicated that surfactant S1 (up to 2%) and DMSO (up to 1,000 mg/L) presented negligible inhibitory effects on TMAH degradation, while surfactant S2 (0.2-1%) might inhibit methanogenic reaction without any TMAH degradation for 3-5 h. At sulfate concentrations higher than 300 mg/L, a complete inhibition of methanogenic reaction and TMAH biodegradation was observed. Results from cloning and sequencing of archaeal 16S rRNA gene fragments showed that Methanosarcina barkeri and Methanosarcina mazei were the dominant methanogens in the UASB treating TMAH-containing TFT-LCD wastewater.
The objectives of this study are: (1) to determine the effect of pH, initial concentration of Fe(2+) and H(2)O(2) dosage on the removal efficiency of MEA by fluidized-bed Fenton process and Fenton process, (2) to determine the optimal conditions for the degradation of ethanolamine from TFT-LCD wastewater by fluidized-bed Fenton process. In the design of experiment, the Box-Behnken design was used to optimize the operating conditions. A removal efficiency of 98.9% for 5mM MEA was achieved after 2h under optimal conditions of pH3, [Fe(2+)]=5mM and [H(2)O(2)]=60mM. Copyright © 2011 Elsevier Ltd. All rights reserved.
This study evaluated biological treatment of TMAH in a full-scale methanogenic up-flow anaerobic sludge blanket (UASB) followed by an aerobic bioreactor. In general, the UASB was able to perform a satisfactory TMAH degradation efficiency, but the effluent COD of the aerobic bioreactor seemed to increase with an increased TMAH in the influent wastewater. The batch test results confirmed that the UASB sludge under methanogenic conditions would be favored over the aerobic ones for TMAH treatment due to its superb ability of handling high strength of TMAH-containing wastewaters. Based on batch experiments, inhibitory chemicals present in TFT-LCD wastewater like surfactants and sulfate should be avoided to secure a stable methanogenic TMAH degradation. Finally, molecular monitoring of Methanomethylovorans hollandica and Methanosarcina mazei in the full-scale plant, the dominant methanogens in the UASB responsible for TMAH degradation, may be beneficial for a stable TMAH treatment performance. Copyright © 2012 Elsevier Ltd. All rights reserved.
International Display Consortium (IDC) is the joining together of display companies to combined their buying power and obtained favorable terms with a major LCD manufacturer. Consolidating the buying power and grouping the demand enables the rugged display industry of avionics, ground vehicles, and ship based display manufacturers to have unencumbered access to high performance AMLCDs while greatly reducing risk and lowering cost. With an unrestricted supply of AMLCD displays, the consortium members have total control of their risk, cost, deliveries and added value partners. Every display manufacturer desires a very close relationship with a display vender. With IDC each consortium member achieves a close relationship. Consortium members enjoy cost effective access to high performance, industry standard sized LCD panels, and modified commercial displays with 100 degree C clearing points and portrait configurations. Consortium members also enjoy proposal support, technical support and long-term support.
Defect detection has been considered an efficient way to increase the yield rate of panels in thin film transistor liquid crystal display (TFT-LCD) manufacturing. In this study we focus on the array process since it is the first and key process in TFT-LCD manufacturing. Various defects occur in the array process, and some of them could cause great damage to the LCD panels. Thus, how to design a method that can robustly detect defects from the images captured from the surface of LCD panels has become crucial. Previously, support vector data description (SVDD) has been successfully applied to LCD defect detection. However, its generalization performance is limited. In this paper, we propose a novel one-class machine learning method, called quasiconformal kernel SVDD (QK-SVDD) to address this issue. The QK-SVDD can significantly improve generalization performance of the traditional SVDD by introducing the quasiconformal transformation into a predefined kernel. Experimental results, carried out on real LCD images provided by an LCD manufacturer in Taiwan, indicate that the proposed QK-SVDD not only obtains a high defect detection rate of 96%, but also greatly improves generalization performance of SVDD. The improvement has shown to be over 30%. In addition, results also show that the QK-SVDD defect detector is able to accomplish the task of defect detection on an LCD image within 60 ms. PMID:22016625
Defect detection has been considered an efficient way to increase the yield rate of panels in thin film transistor liquid crystal display (TFT-LCD) manufacturing. In this study we focus on the array process since it is the first and key process in TFT-LCD manufacturing. Various defects occur in the array process, and some of them could cause great damage to the LCD panels. Thus, how to design a method that can robustly detect defects from the images captured from the surface of LCD panels has become crucial. Previously, support vector data description (SVDD) has been successfully applied to LCD defect detection. However, its generalization performance is limited. In this paper, we propose a novel one-class machine learning method, called quasiconformal kernel SVDD (QK-SVDD) to address this issue. The QK-SVDD can significantly improve generalization performance of the traditional SVDD by introducing the quasiconformal transformation into a predefined kernel. Experimental results, carried out on real LCD images provided by an LCD manufacturer in Taiwan, indicate that the proposed QK-SVDD not only obtains a high defect detection rate of 96%, but also greatly improves generalization performance of SVDD. The improvement has shown to be over 30%. In addition, results also show that the QK-SVDD defect detector is able to accomplish the task of defect detection on an LCD image within 60 ms.
Green supply chain has become an important topic these days due to pollution, global warming, extreme climatic events, etc. A green product is manufactured with the goal of reducing the damage to the environment and limiting the use of energy and other resources at any stage of its life, including raw materials, manufacture, use, and disposal. Carbon footprint is a good measure of the impact that a product has on the environment, especially in climate change, in the entire lifetime of the product. Carbon footprint is directly linked to CO2 emission; thus, the reduction of CO2 emission must be considered in the product life cycle. Although more and more researchers are working on the green supply chain management in the past few years, few have incorporated CO2 emission or carbon footprint into the green supply chain system. Therefore, this research aims to propose an integrated model for facilitating the new product development (NPD) for green and low-carbon products. In this research, a systematic model based on quality function deployment (QFD) is constructed for developing green and low-carbon products in a TFT-LCD manufacturer. Literature review and interviews with experts are done first to collect the factors for developing and manufacturing green and low-carbon products. Fuzzy Delphi method (FDM) is applied next to extract the important factors, and fuzzy interpretive structural modeling (FISM) is used subsequently to understand the relationships among factors. A house of quality (HOQ) for product planning is built last. The results shall provide important information for a TFT-LCD firm in designing a new product.
This study investigated the linkage between performance of two full-scale membrane bioreactor (MBR) systems treating thin-film transistor liquid crystal display (TFT-LCD) wastewater and the population dynamics of dimethylsulfoxide (DMSO)/dimethylsulfide (DMS) degrading bacteria. High DMSO degradation efficiencies were achieved in both MBRs, while the levels of nitrification inhibition due to DMS production from DMSO degradation were different in the two MBRs. The results of real-time PCR targeting on DMSO/DMS degrading populations, including Hyphomicrobium and Thiobacillus spp., indicated that a higher DMSO oxidation efficiency occurred at a higher Hyphomicrobium spp. abundance in the systems, suggesting that Hyphomicrobium spp. may be more important for complete DMSO oxidation to sulfate compared with Thiobacillus spp. Furthermore, Thiobacillus spp. was more abundant during poor nitrification, while Hyphomicrobium spp. was more abundant during good nitrification. It is suggested that microbial population of DMSO/DMS degrading bacteria is closely linking to both DMSO/DMS degradation efficiency and nitrification performance. Copyright © 2013 Elsevier Ltd. All rights reserved.
... 42 Public Health 3 2010-10-01 2010-10-01 false LCD review. 426.425 Section 426.425 Public Health... PROGRAM REVIEW OF NATIONAL COVERAGE DETERMINATIONS AND LOCAL COVERAGE DETERMINATIONS Review of an LCD § 426.425 LCD review. (a) Opportunity for the aggrieved party, after his or her review of the LCD record...
This study investigated nitrification performance and nitrifying community in one full-scale membrane bioreactor (MBR) treating TFT-LCD wastewater. For the A/O MBR system treating monoethanolamine (MEA) and dimethyl sulfoxide (DMSO), no nitrification was observed, due presumably to high organic loading, high colloidal COD, low DO, and low hydraulic retention time (HRT) conditions. By including additional A/O or O/A tanks, the A/O/A/O MBR and the O/A/O MBR were able to perform successful nitrification. The real-time PCR results for quantification of nitrifying populations showed a high correlation to nitrification performance, and can be a good indicator of stable nitrification. Terminal restriction fragment length polymorphism (T-RFLP) results of functional gene, amoA, suggest that Nitrosomonas oligotropha-like AOB seemed to be important to a good nitrification in the MBR system. In the MBR system, Nitrobacter- and Nitrospira-like NOB were both abundant, but the low nitrite environment is likely to promote the growth of Nitrospira-like NOB. Copyright © 2012 Elsevier Ltd. All rights reserved.
The drive for larger size, higher spatial resolution, and wider aperture LCD has shown to increase the electrical crosstalk between electrodes in the driver circuit. This crosstalk leads to additivity errors in color LCD. In this paper, the crosstalk effect was analyzed with micrographs captured from an imaging colorimeter. The experimental result reveals the subpixel nature of color crosstalk. A spatial-based subpixel crosstalk correction algorithm was developed to improve the color performance of LCD. Compared to a 3D lookup table approach, the new algorithm is easier to implement and more accurate in performance.
Field sequential color (FSC) liquid crystal displays (LCD) using a high speed LCD mode and an R, G, B LED backlight, offers a significant potential for lower power consumption, higher resolution, higher brightness and lower cost compared to the conventional R, G, B color filter based LCD, and thus is of interest to various military and avionic display applications. While the DLP projection TVs, and Camcorder LCD view finder type displays using the FSC technology have been introduced in the consumer market, large area direct view LCD displays based on the FSC technology have not reached the commercial market yet. Further, large area FSC LCDs can present unique operational issues in avionic and military environments particularly for operation in a broad temperature range and with respect to its susceptibility for the color breakup image artifact. In this paper we will review the current status of the FSC LCD technology and then discuss the results of our efforts on the FSC LCD technology evaluation for the avionic applications.
This paper discusses an industrial wastewater treatment project performed by Kleinfelder Mexico for an electronics manufacturer located in Guadalajara, Mexico. The industrial wastewater had a moderately high concentration of biochemical oxygen demand (BOD), total suspended solids (TSS), and grease and oil. Metals concentration was low, with only zinc exceeding regulatory standards. The use of aquatic macrophytes (namely Eichhornia crassipes) was considered along with conventional wastewater treatment options. An aquatic macrophyte wastewater treatment system was found to have numerous advantages over a conventional extended aeration package plant. These advantages include less required capital, an appreciation of investment, and lower operations andmore » maintenance costs.« less
In the field of Waste LCD disassembling and recycling, there are existing two major problems: 1) disassembling waste LCD mainly depends on manually mechanical crushing; 2) the resource level is not high. In order to deal with the above problems, in this paper, we develop an efficient, safe and automated waste LCD disassembling assembly line technology. This technology can disassembly and classify mainstream LCD into four components, which are liquid crystal display panels, housings and metal shield, PCB assembly. It can also disassembly many kinds of waste LCD. Compared with the traditional cooperation of manual labor and electric tools method, our proposed technology can significantly improve disassembling efficiency and demonstrate good prospects and promotional value.
... 42 Public Health 3 2013-10-01 2013-10-01 false LCD record furnished to aggrieved party. 426.418... COVERAGE DETERMINATIONS Review of an LCD § 426.418 LCD record furnished to aggrieved party. (a) Elements of a contractor"s LCD record furnished to the aggrieved party. Except as provided in paragraph (b) of...
... 42 Public Health 3 2014-10-01 2014-10-01 false LCD record furnished to aggrieved party. 426.418... COVERAGE DETERMINATIONS Review of an LCD § 426.418 LCD record furnished to aggrieved party. (a) Elements of a contractor"s LCD record furnished to the aggrieved party. Except as provided in paragraph (b) of...
... 42 Public Health 3 2012-10-01 2012-10-01 false LCD record furnished to aggrieved party. 426.418... COVERAGE DETERMINATIONS Review of an LCD § 426.418 LCD record furnished to aggrieved party. (a) Elements of a contractor"s LCD record furnished to the aggrieved party. Except as provided in paragraph (b) of...
... 42 Public Health 3 2010-10-01 2010-10-01 false CMS" role in the LCD review. 426.415 Section 426... Review of an LCD § 426.415 CMS" role in the LCD review. CMS may provide to the ALJ, and all parties to the LCD review, information identifying the person who represents the contractor or CMS, if necessary...
For the first time, an avionic grade MVA AM LCD with wide viewing angle has been developed for use in either landscape or portrait mode. The development of a high resolution Multi-domain Vertical Alignment (MVA) Active Matrix Liquid Crystal Display (AM LCD) is described. Challenges met in this development include achieving the required performance with high luminance and sunlight readability while meeting stringent optical (image quality) and environmental performance requirements of avionics displays. In this paper the optical and environmental performance of this high resolution 14.1" MVA-AM-LCD are discussed and some performance comparisons to conventional AM-LCDs are documented. This AM LCD has found multiple Business Aviation and Military display applications and cockpit pictures are presented.
Stereoscopic display technologies have been developed as one of advanced displays, and many TV industrials have been trying commercialization of 3D TV. We have been developing 3D TV based on LCD with LED BLU (backlight unit) since Samsung launched the world"s first 3D TV based on PDP. However, the data scanning of panel and LC"s response characteristics of LCD TV cause interference among frames (that is crosstalk), and this makes 3D video quality worse. We propose the method to reduce crosstalk by LCD driving and backlight control of FHD 3D LCD TV.
Soluble sodium silicates (waterglass) are liquids containing dissolved glass which have some water like properties. They are widely used in industry as sealants, binders, deflocculants, emulsifiers and buffers. Their most common applications in Egypt are in the pulp and paper industry (where they improve the brightness and efficiency of peroxide bleaching) and the detergent industry, in which they improve the action of the detergent and lower the viscosity of liquid soaps. The survey results showed that the production was carried out batch-wise, in an autoclave (dissolver). Sodium silicate in the state of crushed glass was charged in an autoclave (dissolver) with sodium hydroxide and water. The product is filtered through a press. The left over sludge (mud and silicates impurities) is emptied into the local sewer system. Also, sludge (silica gel) was discharged from the neutralization process of the generated alkaline wastewater and consequently clogging the sewerage system. So this study was carried out to modify the current wastewater management system which eliminates sludge formation, the discharge of higher pH wastewater to the sewer system, and to assess its environmental and economic benefits. To assess the characteristics of wastewater to be reused, physico-chemical parameters of 12 samples were tested using standard methods. The survey results showed that a total capacity of the selected enterprise was 540 tons of liquid sodium silicates monthly. The total amount of wastewater being discharged was 335 m3/month. Reusing of wastewater as feed autoclave water reduced water consumption of 32.1% and reduced wastewater discharge/month that constitutes 89.6% as well as saving in final product of 6 ton/month. It was concluded that reusing of wastewater generated from liquid sodium silicate manufacturing process resulted in cheaper and environmental-friendly product.
A new drive circuit for the liquid crystal display (LCD) of the InFocus TVT-6000 video projector is currently under development at the U.S. Army Missile Command. The new circuit will allow individual pixel control of the LCD and increase the frame rate by a factor of two while yielding a major reduction in space and power requirements. This paper will discuss results of the effort to date.
In this paper, the impact of display on quality assessment is addressed. Subjective quality assessment experiments have been performed on both LCD and CRT displays. Two sets of still images and two sets of moving pictures have been assessed using either an ACR or a SAMVIQ protocol. Altogether, eight experiments have been led. Results are presented and discussed, some differences are pointed out. Concerning moving pictures, these differences seem to be mainly due to LCD moving artefacts such as motion blur. LCD motion blur has been measured objectively and with psycho-physics experiments. A motion-blur metric based on the temporal characteristics of LCD can be defined. A prediction model have been then designed which predict the differences of perceived quality between CRT and LCD. This motion-blur-based model enables the estimation of perceived quality on LCD with respect to the perceived quality on CRT. Technical solutions to LCD motion blur can thus be evaluated on natural contents by this mean.
... Section 426.418 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN... development of the LCD, including, but not limited to, the following: (1) The LCD being challenged. (2) Any... the draft LCD). (4) An index of documents considered that are excluded under paragraph (b) of this...
... Section 426.418 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN... development of the LCD, including, but not limited to, the following: (1) The LCD being challenged. (2) Any... the draft LCD). (4) An index of documents considered that are excluded under paragraph (b) of this...
The electrocoagulation (EC) process was used to pretreat wastewater from the manufacture of wet-spun acrylic fibers, and the effects of varying the operating parameters, including the electrode area/wastewater volume (A/V) ratio, current density, interelectrode distance and pH, on the EC treatment process were investigated. About 44% of the total organic carbon was removed using the optimal conditions in a 100 min procedure. The optimal conditions were a current density of 35.7 mA cm(-2), an A/V ratio of 0.28 cm(-1), a pH of 5, and an interelectrode distance of 0.8 cm. The biodegradability of the contaminants in the treated water was improved by the EC treatment (using the optimal conditions), increasing the five-day biological oxygen demand/chemical oxygen demand ratio to 0.35, which could improve the effectiveness of subsequent biological treatments. The improvement in the biodegradability of the contaminants in the wastewater was attributed to the removal and degradation of aromatic organic compounds, straight-chain paraffins, and other organic compounds, which we identified using gas chromatography-mass spectrometry and Fourier transform infrared spectroscopy. The EC process was proven to be an effective alternative pretreatment for wastewater from the manufacture of wet-spun acrylic fibers, prior to biological treatments. Copyright © 2014 Elsevier B.V. All rights reserved.
Several photo-activated processes have been investigated for oxidation of a cork manufacturing wastewater. A comparative activity study is made between different homogeneous (H2O2/UV-Vis and H2O2/Fe2+/UV-Vis) and heterogeneous (TiO2/UV-Vis and TiO2/H2O2/UV-Vis) systems, with degradation performances being evaluated in terms of total organic carbon (TOC) removal. Results obtained in a batch photo-reactor show that photo-catalysis with TiO2 is not suitable for this kind of wastewater while the H2O2/UV-Vis oxidation process, for which the effect of some operating conditions was investigated, allows to remove 39% of TOC after 4 h of operation (for C(H2O2)=0.59 M, pH=10 and T=35 degrees C). The combined photo-activated process, i.e., using both TiO2 and H2O2, yields an overall TOC decrease of 46% (for C(TiO2)=1.0 gl(-1)). The photo-Fenton process proved to be the most efficient, proceeds at a much higher oxidation rate and allows to achieve 66% mineralization in just 10 min of reaction time (for C(H2O2)=0.31 M, T=30 degrees C, Fe2+:H2O2=0.12 (mol) and pH=3.2).
The aim of this work was to assess the effectiveness of a biological trickling filter for the treatment of wastewaters produced by a company manufacturing organic dyes and varnishes. The combined wastewater effluent was fed to a pilot-scale trickling filter in two feeding modes, continuously and as a sequencing batch reactor (SBR). The biodegradability of the diluted wastewaters that were subjected to physicochemical treatment, using Ca(OH)(2) and FeSO(4), was initially studied using a continuously operated trickling filter. The system efficiency ranged up to 60-70% for a hydraulic loading of 1.1 m(3)/m(2)day and up to 80-85% for a hydraulic loading 0.6 m(3)/m(2)day. A stable chemical oxygen demand (COD) removal efficiency of 60-70% was achieved even in the case of undiluted wastewater at a hydraulic loading of 1.1 m(3)/m(2)day. The effectiveness of biological treatment of a mixture of the company"s main wastewater streams was also examined. The microorganisms developed in the trickling filter were able to efficiently remove COD levels up to 36,000 mg/L, under aerobic conditions at pH values between 5.5 and 8.0. Depending on the operating conditions of the system, about 30-60% of the total COD removal was attributed to air stripping caused by the air supply at the bottom of the filter, whereas the rest of the COD was clearly removed through biological action. The proposed biological treatment process based on a trickling filter, which was operated either continuously or even better in an SBR mode, appears as a promising pretreatment step for coping with dye manufacturing wastewaters in terms of removing a significant portion of the organic content.
The feasibility of the dissolved air flotation (DAF) process in treating chemical mechanical polishing (CMP) wastewater was evaluated in this study. Wastewater from a local semiconductor manufacturer was sampled and characterised. Nano-sized silica (77.6 nm) with turbidity of 130 +/- 3 NTU was found in the slightly alkaline wastewater with traces of other pollutants. Experimental results indicated removal efficiency of particles, measured as suspended particle or turbidity, increased with increasing concentration of cationic collector cetyltrimethyl ammonium bromide (CTAB). When CTAB concentration was 30 mg/L, pH of 6.5 +/- 0.1 and recycle ratio of 30%, very effective removal of particles (> 98%) was observed in saturation pressure range of 4 to 6 kg/cm2, and the reaction proceeded faster under higher pressure. Similarly, the reaction was faster under the higher recycle ratio, while final removal efficiency improved slightly as the recycle ratio increased from 20 to 40%. An insignificant effect of pH on treatment efficiency was found as pH varied from 4.5 to 8.5. The presence of activator, Al3+ and Fe3+, enhanced the system performance. It is proposed that CTAB adsorbs on silica particles in polishing wastewater through electrostatic interaction and makes particles more hydrophobic. The increase in hydrophobicity results in more effective bubble-particle collisions. In addition, flocculation of silica particles through bridging effect of collector was found; it is believed that flocculation of particles also contributed to flotation. Better attachment between gas bubble and solid, higher buoyancy and higher air to solid ratio all lead to effective flotation.
UV lamp systems have been used for cleaning of display panels of TFT LCD or Plasma Display Panel (PDP). However, the needs for high efficient cleaning and low cost made high voltage plasma cleaning techniques to be developed and to be improved. Dielectric-barrier discharges (DBDs), also referred to as barrier discharges or silent discharges have for a long time been exclusively related to ozone generation. In this paper, a 6kW high voltage plasma power supply system was developed for LCD cleaning. The -phase input voltage is rectified and then inverter system is used to make a high frequency pulse train, which is rectified after passing through a high-power transformer. Finally, bi-directional high voltage pulse switching circuits are used to generate the high voltage plasma. Some experimental results showed the usefulness of atmospheric plasma for LCD panel cleaning.
The ozonation performance of wastewater treatment plant secondary effluent of oxytetracycline (OTC) manufacturing wastewater was investigated in terms of ozone dosage and initial pH levels when OTC contributed to a negligible fraction in the chemical oxygen demand (COD) ingredients of the medium-organic-strength wastewater with low biodegradability. A particular emphasis was placed on ammonia, OTC, and residual antibacterial activity (RAA) (evaluated using the objective pathogenic bacterium Staphylococcus aureus). It appears that an ozone dosage of 657 mg L⁻¹ (120 min of reaction) was enough to achieve an OTC abatement of 96%, and COD and biochemical oxygen demand removals of 29% and 33%, respectively, at initial levels of 10.4, 1360, and 300 mg L⁻¹ , respectively. There is a clear correlation between complete OTC depletion and complete RAA disappearance with an increase of ozone dosage. The presence of plentiful non-antibiotic refractory substances influenced the determination of the optimum ozone dosage for biodegradability enhancement and OTC/RAA reduction as well as the ozonation transformation of NH(3). The initial pH adjustment from the original level (pH 9) to pH 11 significantly reduced COD removal while RAA and NH(3) levels were not significantly influenced. Copyright © 2010 Elsevier Ltd. All rights reserved.
This study investigated the opinions of teachers about using interactive whiteboards with an LCD panel that was installed in classrooms within the FATIH educational project. The study was conducted at six high schools in which installation of interactive whiteboards with an LCD panel in classrooms was completed and teachers who received training…
The paper presents an objective lower bound for the discrimination of patterns and fine detail in images on a monochrome LCD. In applications such as medical imaging and military avionics the information of interest is often at the highest frequencies in the image. Since LCDs are sampled data systems, their output modulation is dependent on the phase between the input signal and the sampling points. This phase dependence becomes particularly significant at high spatial frequencies. In order to use an LCD for applications such as those mentioned above it is essential to have a lower (worst case) bound on the performance of the display. We address this problem by providing a mathematical model for the worst case output modulation of an LCD in response to a sine wave input. This function can be interpreted as a worst case modulation transfer function (MTF). The intersection of the worst case MTF with the contrast threshold function (CTF) of the human visual system defines the highest spatial frequency that will always be detectable. In addition to providing the worst case limiting resolution, this MTF is combined with the CTF to produce objective worst case image quality values using the modulation transfer function area (MTFA) metric.
This paper describes and discusses an investigation into the treatment of paint manufacturing wastewater (water-based acrylic texture) by coagulation (aluminum sulfate) coupled to electrochemical methods (BDD electrode). Two proposals are put forward, based on the results. The first proposal considers the feasibility of reusing wastewater treated by the methods separately and in combination, while the second examines the possibility of its disposal into water bodies. To this end, parameters such as toxicity, turbidity, color, organic load, dissolved aluminum, alkalinity, hardness and odor are evaluated. In addition, the proposal for water reuse is strengthened by the quality of the water-based paints produced using the wastewater treated by the two methods (combined and separate), which was evaluated based on the typical parameters for the quality control of these products. Under optimized conditions, the use of the chemical coagulation (12 mL/L of Al2(SO4)3 dosage) treatment, alone, proved the feasibility of reusing the treated wastewater in the paint manufacturing process. However, the use of the electrochemical method (i = 10 mA/cm(2) and t = 90 min) was required to render the treated wastewater suitable for discharge into water bodies. Copyright © 2016 Elsevier Ltd. All rights reserved.
Describes liquid crystal display (LCD) projectors and discusses their use in educational settings. Highlights include rear screen projection; LCD projectors currently available and the number of pixel elements in each; and examples of instructional applications, including portable setups, and use with videocassette recorders (VCRs), computers, and…
... 40 Protection of Environment 10 2014-07-01 2014-07-01 false Process wastewater provisions-wastewater tanks. 63.133 Section 63.133 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater...
... 40 Protection of Environment 10 2012-07-01 2012-07-01 false Process wastewater provisions-wastewater tanks. 63.133 Section 63.133 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater...
... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Process wastewater provisions-wastewater tanks. 63.133 Section 63.133 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater...
... 40 Protection of Environment 10 2013-07-01 2013-07-01 false Process wastewater provisions-wastewater tanks. 63.133 Section 63.133 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater...
The year 2010 may be recorded as a first year of successful commercial 3D products. Among them, the 3D LCD TVs are expected to be the major one regarding the sales volume. In this paper, the principle of current stereoscopic 3D LCD TV techniques and the required flat panel display (FPD) technologies for the realization of them are reviewed. [Figure not available: see fulltext.
Marketing studies by EPIC show significant revenue opportunities by 2012 for UHB-LEDs in the automotive, LCD backlighting, and architectural lighting sectors. The goal of this workshop on manufacturing issues is to consider five key issues for UHB-LED manufacturing and to propose solutions that will pave the way to full exploitation of the opportunities.
In the automatic disassembly line of waste LCD displays, LCD displays are disassembled into plastic shells, metal shields, circuit boards, and LCD panels. Two industrial robots are used to cut metal shields and remove circuit boards in this automatic disassembly line. The functions of these two industrial robots, and the solutions to the critical issues of model selection, the interfaces with PLCs and the workflows were described in detail in this paper.
UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADPO113 31 TITLE: Are the Color Gamuts of CRT and LCD Triangular? An...ADP011297 thru ADP011332 UNCLASSIFIED Are the Color Gamuts of CRT and LCD Triangular? An Experimental Study Guan-wei Leea and Chao-hua Wenb aDepartment of...Tube) display. This study describes the difference of color gamuts in different luminance level and the accuracy of color between CRT and LCD. In the
We have combined a CMOS color camera with special software to compose a multi-functional image-quality analysis instrument. It functions as a colorimeter as well as measuring modulation transfer functions (MTF) and noise power spectra (NPS). It is presently being expanded to examine fixed-pattern noise and temporal noise. The CMOS camera has 9 μm square pixels and a pixel matrix of 2268 x 1512 x 3. The camera uses a sensor that has co-located pixels for all three primary colors. We have imaged sections of both a color and a monochrome LCD monitor onto the camera sensor with LCD-pixel-size to camera-pixel-size ratios of both 12:1 and 17.6:1. When used as an imaging colorimeter, each camera pixel is calibrated to provide CIE color coordinates and tristimulus values. This capability permits the camera to simultaneously determine chromaticity in different locations on the LCD display. After the color calibration with a CS-200 colorimeter the color coordinates of the display"s primaries determined from the camera"s luminance response are very close to those found from the CS-200. Only the color coordinates of the display"s white point were in error. For calculating the MTF a vertical or horizontal line is displayed on the monitor. The captured image is color-matrix preprocessed, Fourier transformed then post-processed. For NPS, a uniform image is displayed on the monitor. Again, the image is pre-processed, transformed and processed. Our measurements show that the horizontal MTF"s of both displays have a larger negative slope than that of the vertical MTF"s. This behavior indicates that the horizontal MTF"s are poorer than the vertical MTF"s. However the modulations at the Nyquist frequency seem lower for the color LCD than for the monochrome LCD. The spatial noise of the color display in both directions is larger than that of the monochrome display. Attempts were also made to analyze the total noise in terms of spatial and temporal noise by applying subtractions of
Application of urea manufacturing wastewater to teak (Tectona grandis) trees, a fast growing tropical timber plants, is an environmentally-friendly and cost-effective alternative for treatment of nitrogen-rich wastewater. However, the plant growth is strongly limited by lack of phosphorus (P) and potassium (K) elements when the plants are irrigated with wastewater containing high concentration of nitrogen (N). A greenhouse experiment was conducted to optimize the efficiency of teak-based remediation systems in terms of nutrient balance. Twelve test solutions consisted of 4 levels of P (95, 190, 570, 1140 mgL -1 ) and 3 levels of K (95, 190, 570 mgL -1 ) with a constant level of N (190 mgL -1 ) were applied to teak seedlings every four days during the study period. Evapotranspiration rate, nutrient removal percentage, leaf surface area, dry weight and nutrient contents of experimental plants were determined and compared with those grown in control solution containing only N (N:P:K = 1:0:0). Teak seedlings grown in units with 1:0.5:1 N:P:K ratio were highly effective at nutrient removal upto 47%, 48% and 49% for N, P and K, respectively. Removal efficiency of teak plants grown in other experimental units decreased with increasing P and K concentrations in test solutions. The lowest nutrient removal and plant growth were recorded in units with 1:6:0.5 N:P:K ratio which received the highest ratio of P to K. The findings indicated that teak seedlings functioned effectively as phytoremediation plants for N-rich wastewater treatment when they were being supplied with proper concentrations of P and K. Copyright © 2017. Published by Elsevier Ltd.
In this study, metal hydroxides generated during electrocoagulation (EC) were used to remove the chemical oxygen demand (COD) of oxide chemical mechanical polishing (oxide-CMP) wastewater from a semiconductor manufacturing plant by EC. Adsorption studies were conducted in a batch system for various current densities and temperatures. The COD concentration in the oxide-CMP wastewater was effectively removed and decreased by more than 90%, resulting in a final wastewater COD concentration that was below the Taiwan discharge standard (100 mg L(-1)). Since the processed wastewater quality exceeded the direct discharge standard, the effluent could be considered for reuse. The adsorption kinetic studies showed that the EC process was best described using the pseudo-second-order kinetic model at the various current densities and temperatures. The experimental data were also tested against different adsorption isotherm models to describe the EC process. The Freundlich adsorption isotherm model predictions matched satisfactorily with the experimental observations. Thermodynamic parameters, including the Gibbs free energy, enthalpy, and entropy, indicated that the COD adsorption of oxide-CMP wastewater on metal hydroxides was feasible, spontaneous and endothermic in the temperature range of 288-318 K. Copyright 2010 Elsevier B.V. All rights reserved.
During the processes of TFT-LCD manufacturing, steps like visual inspection of panel surface defects still heavily rely on manual operations. As the manual inspection time of TFT-LCD manufacturing could range from 4 hours to 1 day, the reliability of time forecasting is thus important for production planning, scheduling and customer response. This study would like to propose a practical and easy-to-implement prediction model through the approach of Bayesian networks for time estimation of manual operated procedures in TFT-LCD manufacturing. Given the lack of prior knowledge about manual operation time, algorithms of necessary path condition and expectation-maximization are used for structural learning and estimation of conditional probability distributions respectively. This study also applied Bayesian inference to evaluate the relationships between explanatory variables and manual operation time. With the empirical applications of this proposed forecasting model, approach of Bayesian networks demonstrates its practicability and prediction accountability.
Cyclo Olefin Polymer (COP), which was developed by Zeon Corporation, is well known and used as an optical plastic in optical markets, having unique properties such as high light transmission, low water absorption, low birefringence etc. Optes Inc, who is ZEON CORPORATION"s affiliate optical parts manufacturer, has succeeded in the development of high performance optical base films. These are used for retardation and polarizing films in LCD"s (Liquid Crystal Displays), made from Cyclo Olefin Polymer with own film extrusion technologies. The Optical base film developed by Optes Inc has superior properties compared with those of existing products such as polycarbonate (PC), polyethylene terephthalate (PET) and Triacetate Cellulose (TAC) base in terms of low birefringence, high optical isotropy and high dimensional stability under high humidity and temperature conditions.
Color gamut as a significant performance index for display system describes the color reproduction ability IN real scenes. Liquid crystal display (LCD) is the most popular technology in flat panel display. However, conventional cold cathode fluorescent lamp (CCFL) backlight of LCD can not behave high color gamut compared with cathode ray tube (CRT). The common used method of color gamut measuring for LCD system is introduced at the beginning. According to the inner structure and display principle