Enhancing the hydrolysis process of a two-stage biogas technology for the organic fraction of municipal solid waste

DEFF Research Database (Denmark)

Nasir, Zeeshan; Uellendahl, Hinrich

2015-01-01

The Danish company Solum A/S has developed a two-stage dry anaerobic digestion process labelled AIKAN® for the biological conversion of the organic fraction of municipal solid waste (OFMSW) into biogas and compost. In the AIKAN® process design the methanogenic (2nd) stage is separated from...... the hydrolytic (1st) stage, which enables pump-free feeding of the waste into the 1st stage (processing module), and eliminates the risk for blocking of pumps and pipes by pumping only the percolate from the 1st stage into the 2nd stage (biogas reactor tank). The biogas yield of the AIKAN® two-stage process......, however, has shown to be only about 60% of the theoretical maximum. Previous monitoring of the hydrolytic and methanogenic activity in the two stages of the process revealed that the bottleneck of the whole degradation process is rather found in the hydrolytic first stage while the methanogenic second...

Operation of a two-stage continuous fermentation process producing hydrogen and methane from artificial food wastes

Energy Technology Data Exchange (ETDEWEB)

Nagai, Kohki; Mizuno, Shiho; Umeda, Yoshito; Sakka, Makiko [Toho Gas Co., Ltd. (Japan); Osaka, Noriko [Tokyo Gas Co. Ltd. (Japan); Sakka, Kazuo [Mie Univ. (Japan)

2010-07-01

An anaerobic two-stage continuous fermentation process with combined thermophilic hydrogenogenic and methanogenic stages (two-stage fermentation process) was applied to artificial food wastes on a laboratory scale. In this report, organic loading rate (OLR) conditions for hydrogen fermentation were optimized before operating the two-stage fermentation process. The OLR was set at 11.2, 24.3, 35.2, 45.6, 56.1, and 67.3 g-COD{sub cr} L{sup -1} day{sup -1} with a temperature of 60 C, pH5.5 and 5.0% total solids. As a result, approximately 1.8-2.0 mol-H{sub 2} mol-hexose{sup -1} was obtained at the OLR of 11.2-56.1 g-COD{sub cr} L{sup -1} day{sup -1}. In contrast, it was inferred that the hydrogen yield at the OLR of 67.3 g-COD{sub cr} L{sup -1} day{sup -1} decreased because of an increase in lactate concentration in the culture medium. The performance of the two-stage fermentation process was also evaluated over three months. The hydraulic retention time (HRT) of methane fermentation was able to be shortened 5.0 days (under OLR 12.4 g-COD{sub cr} L{sup -1} day{sup -1} conditions) when the OLR of hydrogen fermentation was 44.0 g-COD{sub cr} L{sup -1} day{sup -1}, and the average gasification efficiency of the two-stage fermentation process was 81% at the time. (orig.)

Preliminary Results of Cleaning Process for Lubricant Contamination

Science.gov (United States)

Eisenmann, D.; Brasche, L.; Lopez, R.

2006-03-01

Fluorescent penetrant inspection (FPI) is widely used for aviation and other components for surface-breaking crack detection. As with all inspection methods, adherence to the process parameters is critical to the successful detection of defects. Prior to FPI, components are cleaned using a variety of cleaning methods which are selected based on the alloy and the soil types which must be removed. It is also important that the cleaning process not adversely affect the FPI process. There are a variety of lubricants and surface coatings used in the aviation industry which must be removed prior to FPI. To assess the effectiveness of typical cleaning processes on removal of these contaminants, a study was initiated at an airline overhaul facility. Initial results of the cleaning study for lubricant contamination in nickel, titanium and aluminum alloys will be presented.

Preliminary Results of Cleaning Process for Lubricant Contamination

International Nuclear Information System (INIS)

Eisenmann, D.; Brasche, L.; Lopez, R.

2006-01-01

Fluorescent penetrant inspection (FPI) is widely used for aviation and other components for surface-breaking crack detection. As with all inspection methods, adherence to the process parameters is critical to the successful detection of defects. Prior to FPI, components are cleaned using a variety of cleaning methods which are selected based on the alloy and the soil types which must be removed. It is also important that the cleaning process not adversely affect the FPI process. There are a variety of lubricants and surface coatings used in the aviation industry which must be removed prior to FPI. To assess the effectiveness of typical cleaning processes on removal of these contaminants, a study was initiated at an airline overhaul facility. Initial results of the cleaning study for lubricant contamination in nickel, titanium and aluminum alloys will be presented

Hydrogen and methane production from household solid waste in the two-stage fermentation process

DEFF Research Database (Denmark)

Lui, D.; Liu, D.; Zeng, Raymond Jianxiong

2006-01-01

A two-stage process combined hydrogen and methane production from household solid waste was demonstrated working successfully. The yield of 43 mL H-2/g volatile solid (VS) added was generated in the first hydrogen production stage and the methane production in the second stage was 500 mL CH4/g VS...... added. This figure was 21% higher than the methane yield from the one-stage process, which was run as control. Sparging of the hydrogen reactor with methane gas resulted in doubling of the hydrogen production. PH was observed as a key factor affecting fermentation pathway in hydrogen production stage....... Furthermore, this study also provided direct evidence in the dynamic fermentation process that, hydrogen production increase was reflected by acetate to butyrate ratio increase in liquid phase. (c) 2006 Elsevier Ltd. All rights reserved....

Two-stage pervaporation process for effective in situ removal acetone-butanol-ethanol from fermentation broth.

Science.gov (United States)

Cai, Di; Hu, Song; Miao, Qi; Chen, Changjing; Chen, Huidong; Zhang, Changwei; Li, Ping; Qin, Peiyong; Tan, Tianwei

2017-01-01

Two-stage pervaporation for ABE recovery from fermentation broth was studied to reduce the energy cost. The permeate after the first stage in situ pervaporation system was further used as the feedstock in the second stage of pervaporation unit using the same PDMS/PVDF membrane. A total 782.5g/L of ABE (304.56g/L of acetone, 451.98g/L of butanol and 25.97g/L of ethanol) was achieved in the second stage permeate, while the overall acetone, butanol and ethanol separation factors were: 70.7-89.73, 70.48-84.74 and 9.05-13.58, respectively. Furthermore, the theoretical evaporation energy requirement for ABE separation in the consolidate fermentation, which containing two-stage pervaporation and the following distillation process, was estimated less than ∼13.2MJ/kg-butanol. The required evaporation energy was only 36.7% of the energy content of butanol. The novel two-stage pervaporation process was effective in increasing ABE production and reducing energy consumption of the solvents separation system. Copyright © 2016 Elsevier Ltd. All rights reserved.

Outsourcing Housekeeping: An insight into two cleaning companies, SOL and N-Clean, in Helsinki, Finland

OpenAIRE

Hussain, Samra

2016-01-01

The purpose of the author was to find to get an insight into the cleaning companies, in Helsin-ki, Finland, which the hotel industry is using as an external supplier for their housekeeping de-partment. The author has looked into the cleaning companies training process for the cleaning staff, employee demographics, quality control and process of handling complaints. The ad-vantages and disadvantages of outsourcing housekeeping in the hotel sector are also investi-gated. The research method...

Coal preparation and coal cleaning in the dry process; Kanshiki sentaku to coal cleaning

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Z; Morikawa, M; Fujii, Y [Okayama University, Okayama (Japan). Faculty of Engineering

1996-09-01

Because the wet process has a problem such as waste water treatment, coal cleaning in the dry process was discussed. When a fluidized bed (using glass beads and calcium carbonate) is utilized instead of the heavy liquid, the fluidized bed will have apparent density as the liquid does, whereas the relative relationship therewith determines whether a substance having been put into the fluidized bed will float or sink. This is utilized for coals. In addition, two powder constituents of A and B may be wanted to be separated using the fluidized extraction process (similar to the liquid-liquid extraction process). In such a case, a fluidized bed in which both constituents are mixed is added with a third constituent C (which will not mix with A, but mix well with B), where the constituents are separated into A and (B + C), and the (B + C) constituent is separated further by using a sieve. If coal has the coal content mixed with ash content and pulverized, it turns into particle groups which have distributions in grain size and density. Groups having higher density may contain more ash, and those having lower density less ash. In addition, the ash content depends also on the grain size. The ash content may be classified by using simultaneously wind classification (for density and grain size) and a sieve (for grain size). This inference may be expanded to consideration of constructing a multi-stage fluidized bed classification tower. 12 figs., 5 tabs.

Clean Energy Finance: Challenges and Opportunities of Early-Stage Energy Investing (Presentation)

Energy Technology Data Exchange (ETDEWEB)

Heap, D.; Pless, J.; Aieta, N.

2013-12-01

Characterized by a changing landscape and new opportunities, today's increasingly complex energy decision space will need innovative financing and investment models to appropriately assess risk and profitability. This report provides an overview of the current state of clean energy finance across the entire spectrum but with a focus on early stage investing, and it includes insights from investors across all investment classes. Further, this report aims to provide a roadmap with the mechanisms, limitations, and considerations involved in making successful investments by identifying risks, challenges, and opportunities in the clean energy sector.

Tracking the first two seconds: three stages of visual information processing?

Science.gov (United States)

Jacob, Jane; Breitmeyer, Bruno G; Treviño, Melissa

2013-12-01

We compared visual priming and comparison tasks to assess information processing of a stimulus during the first 2 s after its onset. In both tasks, a 13-ms prime was followed at varying SOAs by a 40-ms probe. In the priming task, observers identified the probe as rapidly and accurately as possible; in the comparison task, observers determined as rapidly and accurately as possible whether or not the probe and prime were identical. Priming effects attained a maximum at an SOA of 133 ms and then declined monotonically to zero by 700 ms, indicating reliance on relatively brief visuosensory (iconic) memory. In contrast, the comparison effects yielded a multiphasic function, showing a maximum at 0 ms followed by a minimum at 133 ms, followed in turn by a maximum at 240 ms and another minimum at 720 ms, and finally a third maximum at 1,200 ms before declining thereafter. The results indicate three stages of prime processing that we take to correspond to iconic visible persistence, iconic informational persistence, and visual working memory, with the first two used in the priming task and all three in the comparison task. These stages are related to stages presumed to underlie stimulus processing in other tasks, such as those giving rise to the attentional blink.

Hydrogen production from cellulose in a two-stage process combining fermentation and electrohydrogenesis

KAUST Repository

Lalaurette, Elodie; Thammannagowda, Shivegowda; Mohagheghi, Ali; Maness, Pin-Ching; Logan, Bruce E.

2009-01-01

A two-stage dark-fermentation and electrohydrogenesis process was used to convert the recalcitrant lignocellulosic materials into hydrogen gas at high yields and rates. Fermentation using Clostridium thermocellum produced 1.67 mol H2/mol

Efficient methods of nanoimprint stamp cleaning based on imprint self-cleaning effect

Energy Technology Data Exchange (ETDEWEB)

Meng Fantao; Chu Jinkui [Key Laboratory for Micro/Nano Technology and System of Liaoning Province, Dalian University of Technology, 116024 Dalian (China); Luo Gang; Zhou Ye; Carlberg, Patrick; Heidari, Babak [Obducat AB, SE-20125 Malmoe (Sweden); Maximov, Ivan; Montelius, Lars; Xu, H Q [Division of Solid State Physics, Lund University, Box 118, S-22100 Lund (Sweden); Nilsson, Lars, E-mail: ivan.maximov@ftf.lth.se [Department of Food Technology, Engineering and Nutrition, Lund University, Box 117, S-22100 Lund (Sweden)

2011-05-06

Nanoimprint lithography (NIL) is a nonconventional lithographic technique that promises low-cost, high-throughput patterning of structures with sub-10 nm resolution. Contamination of nanoimprint stamps is one of the key obstacles to industrialize the NIL technology. Here, we report two efficient approaches for removal of typical contamination of particles and residual resist from stamps: thermal and ultraviolet (UV) imprinting cleaning-both based on the self-cleaning effect of imprinting process. The contaminated stamps were imprinted onto polymer substrates and after demolding, they were treated with an organic solvent. The images of the stamp before and after the cleaning processes show that the two cleaning approaches can effectively remove contamination from stamps without destroying the stamp structures. The contact angles of the stamp before and after the cleaning processes indicate that the cleaning methods do not significantly degrade the anti-sticking layer. The cleaning processes reported in this work could also be used for substrate cleaning.

Enhanced nitrogen removal from electroplating tail wastewater through two-staged anoxic-oxic (A/O) process.

Science.gov (United States)

Yan, Xinmei; Zhu, Chunyan; Huang, Bin; Yan, Qun; Zhang, Guangsheng

2018-01-01

Consisted of anaerobic (ANA), anoxic-1 (AN1), aerobic-1 (AE1), anoxic-2 (AN2), aerobic-2 (AE2) reactors and sediment tank, the two-staged A/O process was applied for depth treatment of electroplating tail wastewater with high electrical conductivity and large amounts of ammonia nitrogen. It was found that the NH 4 + -N and COD removal efficiencies reached 97.11% and 83.00%, respectively. Besides, the short-term salinity shock of the control, AE1 and AE2 indicated that AE1 and AE2 have better resistance to high salinity when the concentration of NaCl ranged from 1 to 10g/L. Meanwhile, it was found through high-throughput sequencing that bacteria genus Nitrosomonas, Nitrospira and Thauera, which are capable of nitrogen removal, were enriched in the two-staged A/O process. Moreover, both salt-tolerant bacteria and halophili bacteria were also found in the combined process. Therefore, microbial community within the two-staged A/O process could be acclimated to high electrical conductivity, and adapted for electroplating tail wastewater treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chemical cleaning of UK AGR boilers

International Nuclear Information System (INIS)

Rudge, A.; Turner, P.; Ghosh, A.; Clary, W.; Tice, D.

2002-01-01

For the first time in their operational lives, UK advanced gas-cooled reactor once-through boilers have been chemically cleaned. Chemical cleaning was necessary to avoid lost output resulting from boiler pressure drops, which had been increasing for a number of years. Chemical cleaning of these boilers presents a number of unique difficulties. These include lack of access to the boilers, highly sensitised 316H superheater sections that cannot be excluded from the cleaning flow path, relatively thin boiler tube walls and an intolerance to boiler tube failure because of the role of the boilers in nuclear decay heat removal. The difficulties were overcome by implementing the clean in a staged manner, starting with an extensive materials testwork programme to select and then to substantiate the cleaning process. The selected process was based on ammoniated citric acid plus formic acid for the principal acid cleaning stage. Materials testwork was followed by an in-plant trial clean of six boiler tubes, further materials testwork and the clean of a boiler tube in a full-scale test rig. An overview is presented of the work that was carried out to demonstrate that the clean could be carried out safely, effectively and without leading to unacceptable corrosion losses. Full-scale chemical cleaning was implemented by using as much of the existing plant as possible. Careful control and monitoring was employed to ensure that the cleaning was implemented according to the specified design, thus ensuring that a safe and effective clean was carried out. Full-scale cleaning has resulted in significant boiler pressure drop recovery, even though the iron burden was relatively low and cleaning was completed in a short time. (orig.)

Removal Natural Organic Matter (NOM in Peat Water from Wetland Area by Coagulation-Ultrafiltration Hybrid Process with Pretreatment Two-Stage Coagulation

Directory of Open Access Journals (Sweden)

Mahmud Mahmud

2016-06-01

Full Text Available The primary problem encountered in the application of membrane technology was membrane fouling. During this time, hybrid process by coagulation-ultrafiltration in drinking water treatment that has been conducted by some research, using by one-stage coagulation. The goal of this research was to investigate the effect of two-stage coagulation as a pretreatment towards performance of the coagulation-ultrafiltration hybrid process for removal NOM in the peat water. Coagulation process, either with the one-stage or two-stage coagulation was very good in removing charge hydrophilic fraction, i.e. more than 98%. NOM fractions of the peat water, from the most easily removed by the two-stage coagulation and one-stage coagulation process was charged hydrophilic>strongly hydrophobic>weakly hydrophobic>neutral hydrophilic. The two-stage coagulation process could removed UV254 and colors with a little better than the one-stage coagulation at the optimum coagulant dose. Neutral hydrophilic fraction of peat water NOM was the most influential fraction of UF membrane fouling. The two-stage coagulation process better in removing the neutral hidrophilic fraction, while removing of the charged hydrophilic, strongly hydrophobic and weakly hydrophobic similar to the one-stage coagulation. Hybrid process by pretreatment with two-stage coagulation, beside can increased removal efficiency of UV254 and color, also can reduced fouling rate of the ultrafiltration membraneIt must not exceed 250 words, contains a brief summary of the text, covering the whole manuscript without being too elaborate on every section. Avoid any abbreviation, unless it is a common knowledge or has been previously stated.

Removal Natural Organic Matter (NOM in Peat Water from Wetland Area by Coagulation-Ultrafiltration Hybrid Process with Pretreatment Two-Stage Coagulation

Directory of Open Access Journals (Sweden)

Mahmud Mahmud

2013-11-01

Full Text Available The primary problem encountered in the application of membrane technology was membrane fouling. During this time, hybrid process by coagulation-ultrafiltration in drinking water treatment that has been conducted by some research, using by one-stage coagulation. The goal of this research was to investigate the effect of two-stage coagulation as a pretreatment towards performance of the coagulation-ultrafiltration hybrid process for removal NOM in the peat water. Coagulation process, either with the one-stage or two-stage coagulation was very good in removing charge hydrophilic fraction, i.e. more than 98%. NOM fractions of the peat water, from the most easily removed by the two-stage coagulation and one-stage coagulation process was charged hydrophilic>strongly hydrophobic>weakly hydrophobic>neutral hydrophilic. The two-stage coagulation process could removed UV254 and colors with a little better than the one-stage coagulation at the optimum coagulant dose. Neutral hydrophilic fraction of peat water NOM was the most influential fraction of UF membrane fouling. The two-stage coagulation process better in removing the neutral hidrophilic fraction, while removing of the charged hydrophilic, strongly hydrophobic and weakly hydrophobic similar to the one-stage coagulation. Hybrid process by pretreatment with two-stage coagulation, beside can increased removal efficiency of UV254 and color, also can reduced fouling rate of the ultrafiltration membraneIt must not exceed 250 words, contains a brief summary of the text, covering the whole manuscript without being too elaborate on every section. Avoid any abbreviation, unless it is a common knowledge or has been previously stated.

Enhancement of bioenergy production from organic wastes by two-stage anaerobic hydrogen and methane production process

DEFF Research Database (Denmark)

Luo, Gang; Xie, Li; Zhou, Qi

2011-01-01

The present study investigated a two-stage anaerobic hydrogen and methane process for increasing bioenergy production from organic wastes. A two-stage process with hydraulic retention time (HRT) 3d for hydrogen reactor and 12d for methane reactor, obtained 11% higher energy compared to a single......:12 to 1:14, 6.7%, more energy could be obtained. Microbial community analysis indicated that the dominant bacterial species were different in the hydrogen reactors (Thermoanaerobacterium thermosaccharolyticum-like species) and methane reactors (Clostridium thermocellum-like species). The changes...

Two stages of economic development

OpenAIRE

Gong, Gang

2016-01-01

This study suggests that the development process of a less-developed country can be divided into two stages, which demonstrate significantly different properties in areas such as structural endowments, production modes, income distribution, and the forces that drive economic growth. The two stages of economic development have been indicated in the growth theory of macroeconomics and in the various "turning point" theories in development economics, including Lewis's dual economy theory, Kuznet...

Separation of mercury in industrial processes of Polish hard steam coals cleaning

Directory of Open Access Journals (Sweden)

Wierzchowski Krzysztof

2016-01-01

Full Text Available Coal use is regarded as one of main sources of anthropogenic propagation of mercury in the environment. The coal cleaning is listed among methods of the mercury emission reduction. The article concerns the statistical assessment of mercury separation between coal cleaning products. Two industrial processes employed in the Polish coal preparation plants are analysed: coal cleaning in heavy media vessels and coal cleaning in jigs. It was found that the arithmetic mean mercury content in coarse and medium coal size fractions for clean coal from heavy media vessels, amounts 68.9 μg/kg, and most of the results lay below the mean value, while for rejects it amounts 95.5 μg/kg. It means that it is for around 25 μg/kg greater than in the clean coal. The arithmetic mean mercury content in raw coal smalls amounts around 118 mg/kg. The cleaning of smalls in jigs results in clean coal and steam coal blends characterized by mean mercury content 96.8 μg/kg and rejects with mean mercury content 184.5 μg/kg.

Development of an innovative two-stage process, a combination of acidogenic hydrogenesis and methanogenesis

Energy Technology Data Exchange (ETDEWEB)

Han, S.K.; Shin, H.S. [Korea Advanced Inst. of Science and Technology, Daejeon (Korea, Republic of). Dept. of Civil and Enviromental Engineering

2004-07-01

Hydrogen produced from waste by means of fermentative bacteria is an attractive way to produce this fuel as an alternative to fossil fuels. It also helps treat the associated waste. The authors have undertaken to optimize acidogenic hydrogenesis and methanogenesis. Building on this, they then developed a two-stage process that produces both hydrogen and methane. Acidogenic hydrogenesis of food waste was investigated using a leaching bed reactor. The dilution rate was varied in order to maximize efficiency which was as high as 70.8 per cent. Further to this, an upflow anaerobic sludge blanket reactor converted the wastewater from acidogenic hydrogenesis into methane. Chemical oxygen demand (COD) removal rates exceeded 96 per cent up to a COD loading of 12.9 COD/l/d. After this, the authors devised a new two-stage process based on a combination of acidogenic hydrogenesis and methanogenesis. The authors report on results for this process using food waste as feedstock. 5 refs., 5 figs.

Noncontact COS charge analysis for in-line monitoring of wet cleaning processes

Science.gov (United States)

Zhang, Xiafang; Juang, Min; Tai, Sung-Shan; Chen, Kuo-in; Wossen, Ejigu; Horner, Gregory

1998-08-01

Contamination levels in chemical cleaning equipment and wafer cleanliness in general are very critical to semiconductor manufacturers. In this work, a Keithley Instruments non contact electrical tester (Quantox) is used to measure the mobile ion (Qm) contamination in a variety of cleaning processes. Results show that photoresist strip cleaning process has a higher mobile ion concentration than standard pre-diffusion cleaning process. RCA1, RCA2 and HF solutions mapping measured by the Quantox indicates some negative static charges on the surface after cleaning. This negative field appears to assist Qm removal during wet chemical cleaning. The dependence of flatband voltage and other oxide charges on various cleaning processes has also been investigated using the Quantox. The data suggests that a dipole layer has been formed by a surface reaction during chemical cleaning.

Processing method for cleaning water waste from cement kneader

International Nuclear Information System (INIS)

Soda, Kenzo; Fujita, Hisao; Nakajima, Tadashi.

1990-01-01

The present invention concerns a method of processing cleaning water wastes from a cement kneader in a case of processing liquid wastes containing radioactive wastes or deleterious materials such as heavy metals by means of cement solidification. Cleaning waste wastes from the kneader are sent to a cleaning water waste tank, in which gentle stirring is applied near the bottom and sludges are retained so as not to be coagulated. Sludges retained at the bottom of the cleaning water waste tank are sent after elapse of a predetermined time and then kneaded with cements. Thus, since the sludges in the cleaning water are solidified with cement, inhomogenous solidification products consisting only of cleaning sludges with low strength are not formed. The resultant solidification product is homogenous and the compression strength thereof reaches such a level as capable of satisfying marine disposal standards required for the solidification products of radioactive wastes. (I.N.)

Two-step two-stage fission gas release model

International Nuclear Information System (INIS)

Kim, Yong-soo; Lee, Chan-bock

2006-01-01

Based on the recent theoretical model, two-step two-stage model is developed which incorporates two stage diffusion processes, grain lattice and grain boundary diffusion, coupled with the two step burn-up factor in the low and high burn-up regime. FRAPCON-3 code and its in-pile data sets have been used for the benchmarking and validation of this model. Results reveals that its prediction is in better agreement with the experimental measurements than that by any model contained in the FRAPCON-3 code such as ANS 5.4, modified ANS5.4, and Forsberg-Massih model over whole burn-up range up to 70,000 MWd/MTU. (author)

The rearrangement process in a two-stage broadcast switching network

DEFF Research Database (Denmark)

Jacobsen, Søren B.

1988-01-01

The rearrangement process in the two-stage broadcast switching network presented by F.K. Hwang and G.W. Richards (ibid., vol.COM-33, no.10, p.1025-1035, Oct. 1985) is considered. By defining a certain function it is possible to calculate an upper bound on the number of connections to be moved...... during a rearrangement. When each inlet channel appears twice, the maximum number of connections to be moved is found. For a special class of inlet assignment patterns in the case of which each inlet channel appears three times, the maximum number of connections to be moved is also found. In the general...

Two-Step Plasma Process for Cleaning Indium Bonding Bumps

Science.gov (United States)

Greer, Harold F.; Vasquez, Richard P.; Jones, Todd J.; Hoenk, Michael E.; Dickie, Matthew R.; Nikzad, Shouleh

2009-01-01

A two-step plasma process has been developed as a means of removing surface oxide layers from indium bumps used in flip-chip hybridization (bump bonding) of integrated circuits. The two-step plasma process makes it possible to remove surface indium oxide, without incurring the adverse effects of the acid etching process.

Update-processing steam generator cleaning solvent at Palo Verde

International Nuclear Information System (INIS)

Peters, G.

1996-01-01

Framatome Technologies Inc.(FTI) recently completed the steam generator chemical cleanings at the Palo Verde Nuclear Generating Station Units 1, 2 and 3. Over 500,000 gallons of low-level radioactive solvents were generated during these cleanings and were processed on-site. Chemical cleaning solutions containing high concentrations of organic chelating wastes are difficult to reduce in volume using standard technologies. The process that was ultimately used at Palo Verde involved three distinct processing steps: The evaporation step was conducted using FTI's submerged combustion evaporator (SCE) that has also been successfully used at Arkansas Nuclear One - Unit 1, Three Mile Island - Unit 1, and Oconee on similar waste. The polishing step of the distillate used ultrafiltration (UF) and reverse osmosis (RO) technology that was also used extensively by Ontario Hydro to assist in their processing of chemical cleaning solvent. This technology, equipment, and operations personnel were provided by Zenon Environmental, Inc. The concentrate from the evaporator was absorbed with a special open-quotes peat mossclose quotes based media that allowed it to be shipped and buried at the Environcare of Utah facility. This is the first time that this absorption media or burial site has been used for chemical cleaning solvent

Material compatibility and corrosion control of the KWU chemical cleaning process

International Nuclear Information System (INIS)

Odar, S.

1994-01-01

The concentrations of salt impurities within the deposits on the tube sheet and in the tube to tube-support-plate crevices can induce a variety of corrosion mechanisms on steam generator tubes. One of the most effective ways of counteracting corrosion mechanisms and thus of improving steam generator performance is to clean the steam generators and keep them in a clean condition. As shown by field results chemical cleaning is a way of removing hazardous deposits from steam generators. All available chemical cleaning processes use inhibitors to control the corrosion except the KWU chemical cleaning process. In this article the corrosion control technique of KWU Chemical Cleaning Process without using conventional inhibitors will be explained and the state of the field experience with respect to material compatibility will be presented. (author). 4 figs., 1 tab., 8 refs

EPRI/Alberta Research Council Clean Soil Process

International Nuclear Information System (INIS)

Spear, C.E.

1992-12-01

The EPRI/Alberta Research Council Clean Soil Process can remove hydrocarbon contamination from waste material from manufactured gas plants. The process uses coal as an absorbent to remove hydrocarbons. For petroleum contaminated soils, the process can bring residual concentration of petroleum below 0.1 percent and polycyclic aromatic hydrocarbon (PAH) concentration to 1--5 ppM. For coal tar contaminated soils, the process can reduce tar concentrations to about 0.05-0.5 percent and the PAH concentration to about 10--60 ppM. Additional post-treatment may be required for some precleaned soils. The process yields by-product agglomerates suitable for combustion in industrial boilers. Light hydrocarbons such as benzene are vaporized from the soil, condensed and collected in the Process and disposed of off-site. The Clean Soil Process has been tested at pilot-plant scale. A conceptual design for a 200-tons-per-day plant yielded a capital cost estimated at $3.1 million with a per-ton operating cost of $40

A preventive maintenance model with a two-level inspection policy based on a three-stage failure process

International Nuclear Information System (INIS)

Wang, Wenbin; Zhao, Fei; Peng, Rui

2014-01-01

Inspection is always an important preventive maintenance (PM) activity and can have different depths and cover all or part of plant systems. This paper introduces a two-level inspection policy model for a single component plant system based on a three-stage failure process. Such a failure process divides the system′s life into three stages: good, minor defective and severe defective stages. The first level of inspection, the minor inspection, can only identify the minor defective stage with a certain probability, but can always reveal the severe defective stage. The major inspection can however identify both defective stages perfectly. Once the system is found to be in the minor defective stage, a shortened inspection interval is adopted. If however the system is found to be in the severe defective stage, we may delay the maintenance action if the time to the next planned PM window is less than a threshold level, but otherwise, replace immediately. This corresponds to the well adopted maintenance policy in practice such as periodic inspections with planned PMs. A numerical example is presented to demonstrate the proposed model by comparing with other models. - Highlights: • The system′s deterioration goes through a three-stage process, namely, normal, minor defective and severe defective. • Two levels of inspections are proposed, e.g., minor and major inspections. • Once the minor defective stage is found, instead of taking a maintenance action, a shortened inspection interval is recommended. • When the severe defective stage is found, we delay the maintenance according to the threshold to the next PM. • The decision variables are the inspection intervals and the threshold to PM

Two-stage precipitation of neptunium (IV) oxalate

International Nuclear Information System (INIS)

Luerkens, D.W.

1983-07-01

Neptunium (IV) oxalate was precipitated using a two-stage precipitation system. A series of precipitation experiments was used to identify the significant process variables affecting precipitate characteristics. Process variables tested were input concentrations, solubility conditions in the first stage precipitator, precipitation temperatures, and residence time in the first stage precipitator. A procedure has been demonstrated that produces neptunium (IV) oxalate particles that filter well and readily calcine to the oxide

Optimizing a cleaning process for multilayer-dielectric- (MLD) diffraction gratings

Energy Technology Data Exchange (ETDEWEB)

Ashe, B. [Univ. of Rochester, NY (United States); Giacofei, C. [Univ. of Rochester, NY (United States); Myhre, G. [Univ. of Rochester, NY (United States); Schmid, A. W. [Univ. of Rochester, NY (United States)

2007-12-20

An essential component for the OMEGA EP short-pulse petawatt laser system is the grating compressor chamber (GCC). This large (12,375 ft³) vacuum chamber contains critical optics where laser-pulse compression is performed at the output of the system on two 40-cm-sq-aperture, IR (1054-nm) laser beams. Critical to this compression, within the GCC, are four sets of tiled multilayer-dielectric- (MLD) diffraction gratings that provide the capability for producing 2.6-kJ output IR energy per beam at 10 ps. The primary requirements for these large-aperture (43-cm × 47-cm) gratings are diffraction efficiencies greater than 95%, peak-to-valley wavefront quality of less than λ/10 waves, and laser-induced-damage thresholds greater than 2.7 J/cm² at 10-ps measured beam normal. Degradation of the grating laser-damage threshold due to adsorption of contaminants from the manufacturing process must be prevented to maintain system performance. In this paper we discuss an optimized cleaning process to achieve the OMEGA EP requirements. The fabrication of MLD gratings involves processes that utilize a wide variety of both organic materials (photoresist processes) and inorganic materials (metals and metal oxides) that can affect the final cleaning process. Finally, a number of these materials have significant optical absorbance; therefore, incomplete cleaning of these residues may result in the MLD gratings experiencing laser damage.

Field experience with KWU SG chemical cleaning process

International Nuclear Information System (INIS)

Odar, S.

1989-01-01

The ingress of corrosion products into PWR steam generators (SG's) their deposition and the subsequent concentration of salt impurities can induce a variety of mechanisms for corrosion attack on SG tubing. Already, some plants have had to replace their steam generators due to severe corrosion damage and others are seriously considering the same costly action in the near future. One of the most effective ways to counteract corrosion mechanisms and thus to reduce the likelihood of SG replacement becoming necessary is to clean the SG's and to keep them clean. For many years, the industry has been involved in developing different types of cleaning techniques. Among these, chemical cleaning has been shown to be especially effective. In this article, the KWU chemical cleaning process, for which there is considerable application experience, is described. The results of field applications will be presented together with material compatibility data and information on cleaning effectiveness. (author)

Comparative assessment of single-stage and two-stage anaerobic digestion for the treatment of thin stillage.

Science.gov (United States)

Nasr, Noha; Elbeshbishy, Elsayed; Hafez, Hisham; Nakhla, George; El Naggar, M Hesham

2012-05-01

A comparative evaluation of single-stage and two-stage anaerobic digestion processes for biomethane and biohydrogen production using thin stillage was performed to assess the impact of separating the acidogenic and methanogenic stages on anaerobic digestion. Thin stillage, the main by-product from ethanol production, was characterized by high total chemical oxygen demand (TCOD) of 122 g/L and total volatile fatty acids (TVFAs) of 12 g/L. A maximum methane yield of 0.33 L CH(4)/gCOD(added) (STP) was achieved in the two-stage process while a single-stage process achieved a maximum yield of only 0.26 L CH(4)/gCOD(added) (STP). The separation of acidification stage increased the TVFAs to TCOD ratio from 10% in the raw thin stillage to 54% due to the conversion of carbohydrates into hydrogen and VFAs. Comparison of the two processes based on energy outcome revealed that an increase of 18.5% in the total energy yield was achieved using two-stage anaerobic digestion. Copyright © 2012 Elsevier Ltd. All rights reserved.

Chemical-cleaning process evaluation: Westinghouse steam generators. Final report

International Nuclear Information System (INIS)

Cleary, W.F.; Gockley, G.B.

1983-04-01

The Steam Generator Owners Group (SGOG)/Electric Power Research Institute (EPRI) Steam Generator Secondary Side Chemical Cleaning Program, under develpment since 1978, has resulted in a generic process for the removal of accumulated corrosion products and tube deposits in the tube support plate crevices. The SGOG/EPRI Project S150-3 was established to obtain an evaluation of the generic process in regard to its applicability to Westinghouse steam generators. The results of the evaluation form the basis for recommendations for transferring the generic process to a plant specific application and identify chemical cleaning corrosion guidelines for the materials in Westinghouse Steam Generators. The results of the evaluation, recommendations for plant-specific applications and corrosion guidelines for chemical cleaning are presented in this report

Comparisons of single-stage and two-stage approaches to genomic selection.

Science.gov (United States)

Schulz-Streeck, Torben; Ogutu, Joseph O; Piepho, Hans-Peter

2013-01-01

Genomic selection (GS) is a method for predicting breeding values of plants or animals using many molecular markers that is commonly implemented in two stages. In plant breeding the first stage usually involves computation of adjusted means for genotypes which are then used to predict genomic breeding values in the second stage. We compared two classical stage-wise approaches, which either ignore or approximate correlations among the means by a diagonal matrix, and a new method, to a single-stage analysis for GS using ridge regression best linear unbiased prediction (RR-BLUP). The new stage-wise method rotates (orthogonalizes) the adjusted means from the first stage before submitting them to the second stage. This makes the errors approximately independently and identically normally distributed, which is a prerequisite for many procedures that are potentially useful for GS such as machine learning methods (e.g. boosting) and regularized regression methods (e.g. lasso). This is illustrated in this paper using componentwise boosting. The componentwise boosting method minimizes squared error loss using least squares and iteratively and automatically selects markers that are most predictive of genomic breeding values. Results are compared with those of RR-BLUP using fivefold cross-validation. The new stage-wise approach with rotated means was slightly more similar to the single-stage analysis than the classical two-stage approaches based on non-rotated means for two unbalanced datasets. This suggests that rotation is a worthwhile pre-processing step in GS for the two-stage approaches for unbalanced datasets. Moreover, the predictive accuracy of stage-wise RR-BLUP was higher (5.0-6.1%) than that of componentwise boosting.

Occupational radon expositions during cleaning processes of water reservoirs

International Nuclear Information System (INIS)

Hingmann, H.; Ehret, V.; Hegenbart, L.; Krieg, K.

2002-01-01

According to the new German ''Strahlenschutzverordnung'' (Radiation Protection Directive) the annual dose due to the exposition to radon has to be estimated for employees of water works. This includes employees of service companies. While the job of employees of water works usually covers a broad spectrum of different activities, employees of service companies may spend a considerable amount of time of their total working hours cleaning water reservoirs. This investigation is concerned with this type of employees. The radon exposition of one or more cleaning processes were determined by passive dosimeters. The mean radon concentration was calculated for the duration of the cleaning process. In some cases, members of the project team accompanied cleaning processes and performed stationary radon measurements on site. Sometimes, parallel to the passive dosimeters, electronic dosimeters were used to measure personal exposure. The results - and results from additional laboratory reference measurements - are compared. All results until January 2002 are considered. The project still goes on and will end in summer of 2002. Experiences made during this investigation are described in the end of this report. (orig.)

Alternative, Green Processes for the Precision Cleaning of Aerospace Hardware

Science.gov (United States)

Maloney, Phillip R.; Grandelli, Heather Eilenfield; Devor, Robert; Hintze, Paul E.; Loftin, Kathleen B.; Tomlin, Douglas J.

2014-01-01

Precision cleaning is necessary to ensure the proper functioning of aerospace hardware, particularly those systems that come in contact with liquid oxygen or hypergolic fuels. Components that have not been cleaned to the appropriate levels may experience problems ranging from impaired performance to catastrophic failure. Traditionally, this has been achieved using various halogenated solvents. However, as information on the toxicological and/or environmental impacts of each came to light, they were subsequently regulated out of use. The solvent currently used in Kennedy Space Center (KSC) precision cleaning operations is Vertrel MCA. Environmental sampling at KSC indicates that continued use of this or similar solvents may lead to high remediation costs that must be borne by the Program for years to come. In response to this problem, the Green Solvents Project seeks to develop state-of-the-art, green technologies designed to meet KSCs precision cleaning needs.Initially, 23 solvents were identified as potential replacements for the current Vertrel MCA-based process. Highly halogenated solvents were deliberately omitted since historical precedents indicate that as the long-term consequences of these solvents become known, they will eventually be regulated out of practical use, often with significant financial burdens for the user. Three solvent-less cleaning processes (plasma, supercritical carbon dioxide, and carbon dioxide snow) were also chosen since they produce essentially no waste stream. Next, experimental and analytical procedures were developed to compare the relative effectiveness of these solvents and technologies to the current KSC standard of Vertrel MCA. Individually numbered Swagelok fittings were used to represent the hardware in the cleaning process. First, the fittings were cleaned using Vertrel MCA in order to determine their true cleaned mass. Next, the fittings were dipped into stock solutions of five commonly encountered contaminants and were

Single-stage versus two-stage anaerobic fluidized bed bioreactors in treating municipal wastewater: Performance, foulant characteristics, and microbial community.

Science.gov (United States)

Wu, Bing; Li, Yifei; Lim, Weikang; Lee, Shi Lin; Guo, Qiming; Fane, Anthony G; Liu, Yu

2017-03-01

This study examined the receptive performance, membrane foulant characteristics, and microbial community in the single-stage and two-stage anaerobic fluidized membrane bioreactor (AFMBR) treating settled raw municipal wastewater with the aims to explore fouling mechanisms and microbial community structure in both systems. Both AFMBRs exhibited comparable organic removal efficiency and membrane performances. In the single-stage AFMBR, less soluble organic substances were removed through biosorption by GAC and biodegradation than those in the two-stage AFMBR. Compared to the two-stage AFMBR, the formation of cake layer was the main cause of the observed membrane fouling in the single-stage AFMBR at the same employed flux. The accumulation rate of the biopolymers was linearly correlated with the membrane fouling rate. In the chemical-cleaned foulants, humic acid-like substances and silicon were identified as the predominant organic and inorganic fouants respectively. As such, the fluidized GAC particles might not be effective in removing these substances from the membrane surfaces. High-throughout pyrosequencing analysis further revealed that beta-Proteobacteria were predominant members in both AFMBRs, which contributed to the development of biofilms on the fluidized GAC and membrane surfaces. However, it was also noted that the abundance of the identified dominant in the membrane surface-associated biofilm seemed to be related to the permeate flux and reactor configuration. Copyright © 2016 Elsevier Ltd. All rights reserved.

A two-stage biological gas to liquid transfer process to convert carbon dioxide into bioplastic

KAUST Repository

Al Rowaihi, Israa; Kick, Benjamin; Grö tzinger, Stefan W.; Burger, Christian; Karan, Ram; Weuster-Botz, Dirk; Eppinger, Jö rg; Arold, Stefan T.

2018-01-01

The fermentation of carbon dioxide (CO2) with hydrogen (H2) uses available low-cost gases to synthesis acetic acid. Here, we present a two-stage biological process that allows the gas to liquid transfer (Bio-GTL) of CO2 into the biopolymer

A two-stage bio hydrogen process for energy generation from municipal solid wastes

International Nuclear Information System (INIS)

Acevedo-Benitez, J. a.; Poggi-Varaldo, H. M.

2009-01-01

Energy supply and disposal of solid wastes are two big challenges that great cities face at the present time. Several experts have shown that hydrogen is the fuel of the future, due to their high energy content (three times more than that of the gasoline) and its clean combustion. (Author)

Fate of dissolved organic nitrogen in two stage trickling filter process.

Science.gov (United States)

Simsek, Halis; Kasi, Murthy; Wadhawan, Tanush; Bye, Christopher; Blonigen, Mark; Khan, Eakalak

2012-10-15

Dissolved organic nitrogen (DON) represents a significant portion of nitrogen in the final effluent of wastewater treatment plants (WWTPs). Biodegradable portion of DON (BDON) can support algal growth and/or consume dissolved oxygen in the receiving waters. The fate of DON and BDON has not been studied for trickling filter WWTPs. DON and BDON data were collected along the treatment train of a WWTP with a two-stage trickling filter process. DON concentrations in the influent and effluent were 27% and 14% of total dissolved nitrogen (TDN). The plant removed about 62% and 72% of the influent DON and BDON mainly by the trickling filters. The final effluent BDON values averaged 1.8 mg/L. BDON was found to be between 51% and 69% of the DON in raw wastewater and after various treatment units. The fate of DON and BDON through the two-stage trickling filter treatment plant was modeled. The BioWin v3.1 model was successfully applied to simulate ammonia, nitrite, nitrate, TDN, DON and BDON concentrations along the treatment train. The maximum growth rates for ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria, and AOB half saturation constant influenced ammonia and nitrate output results. Hydrolysis and ammonification rates influenced all of the nitrogen species in the model output, including BDON. Copyright © 2012 Elsevier Ltd. All rights reserved.

Production of long chain alkyl esters from carbon dioxide and electricity by a two-stage bacterial process.

Science.gov (United States)

Lehtinen, Tapio; Efimova, Elena; Tremblay, Pier-Luc; Santala, Suvi; Zhang, Tian; Santala, Ville

2017-11-01

Microbial electrosynthesis (MES) is a promising technology for the reduction of carbon dioxide into value-added multicarbon molecules. In order to broaden the product profile of MES processes, we developed a two-stage process for microbial conversion of carbon dioxide and electricity into long chain alkyl esters. In the first stage, the carbon dioxide is reduced to organic compounds, mainly acetate, in a MES process by Sporomusa ovata. In the second stage, the liquid end-products of the MES process are converted to the final product by a second microorganism, Acinetobacter baylyi in an aerobic bioprocess. In this proof-of-principle study, we demonstrate for the first time the bacterial production of long alkyl esters (wax esters) from carbon dioxide and electricity as the sole sources of carbon and energy. The process holds potential for the efficient production of carbon-neutral chemicals or biofuels. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development, testing, and demonstration of an optimal fine coal cleaning circuit

International Nuclear Information System (INIS)

Mishra, M.; Placha, M.; Bethell, P.

1995-01-01

The overall objective of this project is to improve the efficiency of fine coal cleaning. The project will be completed in two phases: bench-scale testing and demonstration of four advanced flotation cells and; in-plant proof-of-concept (POC) pilot plant testing of two flotation cells individually and in two-stage combinations. The goal is to ascertain if a two-stage circuit can result in reduced capital and operating costs while achieving improved separation efficiency. The plant selected for this project, Cyprus Emerald Coal Preparation plant, cleans 1200 tph of raw coal. The plant produces approximately 4 million tonnes of clean coal per year at an average as received energy content of 30.2 MJ/Kg (13,000 Btu/lb)

Development, testing, and demonstration of an optimal fine coal cleaning circuit

Energy Technology Data Exchange (ETDEWEB)

Mishra, M.; Placha, M.; Bethell, P. [and others

1995-11-01

The overall objective of this project is to improve the efficiency of fine coal cleaning. The project will be completed in two phases: bench-scale testing and demonstration of four advanced flotation cells and; in-plant proof-of-concept (POC) pilot plant testing of two flotation cells individually and in two-stage combinations. The goal is to ascertain if a two-stage circuit can result in reduced capital and operating costs while achieving improved separation efficiency. The plant selected for this project, Cyprus Emerald Coal Preparation plant, cleans 1200 tph of raw coal. The plant produces approximately 4 million tonnes of clean coal per year at an average as received energy content of 30.2 MJ/Kg (13,000 Btu/lb).

Accuracy of the One-Stage and Two-Stage Impression Techniques: A Comparative Analysis.

Science.gov (United States)

Jamshidy, Ladan; Mozaffari, Hamid Reza; Faraji, Payam; Sharifi, Roohollah

2016-01-01

Introduction . One of the main steps of impression is the selection and preparation of an appropriate tray. Hence, the present study aimed to analyze and compare the accuracy of one- and two-stage impression techniques. Materials and Methods . A resin laboratory-made model, as the first molar, was prepared by standard method for full crowns with processed preparation finish line of 1 mm depth and convergence angle of 3-4°. Impression was made 20 times with one-stage technique and 20 times with two-stage technique using an appropriate tray. To measure the marginal gap, the distance between the restoration margin and preparation finish line of plaster dies was vertically determined in mid mesial, distal, buccal, and lingual (MDBL) regions by a stereomicroscope using a standard method. Results . The results of independent test showed that the mean value of the marginal gap obtained by one-stage impression technique was higher than that of two-stage impression technique. Further, there was no significant difference between one- and two-stage impression techniques in mid buccal region, but a significant difference was reported between the two impression techniques in MDL regions and in general. Conclusion . The findings of the present study indicated higher accuracy for two-stage impression technique than for the one-stage impression technique.

Combined two-stage xanthate processes for the treatment of copper-containing wastewater

Energy Technology Data Exchange (ETDEWEB)

Chang, Y.K. [Department of Safety Health and Environmental Engineering, Central Taiwan University of Sciences and Technology, Taichung (Taiwan); Leu, M.H. [Department of Environmental Engineering, Kun Shan University of Technology, Yung-Kang City (Taiwan); Chang, J.E.; Lin, T.F.; Chen, T.C. [Department of Environmental Engineering, National Cheng Kung University, Tainan City (Taiwan); Chiang, L.C.; Shih, P.H. [Department of Environmental Engineering and Science, Fooyin University, Kaohsiung County (Taiwan)

2007-02-15

Heavy metal removal is mainly conducted by adjusting the wastewater pH to form metal hydroxide precipitates. However, in recent years, the xanthate process with a high metal removal efficiency, attracted attention due to its use of sorption/desorption of heavy metals from aqueous solutions. In this study, two kinds of agricultural xanthates, insoluble peanut-shell xanthate (IPX) and insoluble starch xanthate (ISX), were used as sorbents to treat the copper-containing wastewater (Cu concentration from 50 to 1,000 mg/L). The experimental results showed that the maximum Cu removal efficiency by IPX was 93.5 % in the case of high Cu concentrations, whereby 81.1 % of copper could rapidly be removed within one minute. Moreover, copper-containing wastewater could also be treated by ISX over a wide range (50 to 1,000 mg/L) to a level that meets the Taiwan EPA's effluent regulations (3 mg/L) within 20 minutes. Whereas IPX had a maximum binding capacity for copper of 185 mg/g IPX, the capacity for ISX was 120 mg/g ISX. IPX is cheaper than ISX, and has the benefits of a rapid reaction and a high copper binding capacity, however, it exhibits a lower copper removal efficiency. A sequential IPX and ISX treatment (i.e., two-stage xanthate processes) could therefore be an excellent alternative. The results obtained using the two-stage xanthate process revealed an effective copper treatment. The effluent (C{sub e}) was below 0.6 mg/L, compared to the influent (C{sub 0}) of 1,001 mg/L at pH = 4 and a dilution rate of 0.6 h{sup -1}. Furthermore, the Cu-ISX complex formed could meet the Taiwan TCLP regulations, and be classified as non-hazardous waste. The xanthatilization of agricultural wastes offers a comprehensive strategy for solving both agricultural waste disposal and metal-containing wastewater treatment problems. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

Innovative technologies on fuel assemblies cleaning for sodium fast reactors: First considerations on cleaning process

International Nuclear Information System (INIS)

Simon, N.; Lorcet, H.; Beauchamp, F.; Guigues, E.; Lovera, P.; Fleche, J. L.; Lacroix, M.; Carra, O.; Dechelette, F.; Prele, G.; Rodriguez, G.

2012-01-01

Within the framework of Sodium Fast Reactor development, innovative fuel assembly cleaning operations are investigated to meet the GEN IV goals of safety and of process development. One of the challenges is to mitigate the Sodium Water Reaction currently used in these processes. The potential applications of aqueous solutions of mineral salts (including the possibility of using redox chemical reactions) to mitigate the Sodium Water Reaction are considered in a first part and a new experimental bench, dedicated to this study, is described. Anhydrous alternative options based on Na/CO 2 interaction are also presented. Then, in a second part, a functional study conducted on the cleaning pit is proposed. Based on experimental feedback, some calculations are carried out to estimate the sodium inventory on the fuel elements, and physical methods like hot inert gas sweeping to reduce this inventory are also presented. Finally, the implementation of these innovative solutions in cleaning pits is studied in regard to the expected performances. (authors)

Innovative technologies on fuel assemblies cleaning for sodium fast reactors: First considerations on cleaning process

Energy Technology Data Exchange (ETDEWEB)

Simon, N.; Lorcet, H.; Beauchamp, F.; Guigues, E. [CEA, DEN, DTN Cadarache, F-13108 Saint-Paul-lez-Durance (France); Lovera, P.; Fleche, J. L. [CEA, DEN, DPC Saclay, F-91191 Gif-sur-Yvette (France); Lacroix, M. [CEA, DEN, DTN Cadarache, F-13108 Saint-Paul-lez-Durance (France); Carra, O. [AREVA / NP, 10 Rue Juliette Recamier, 69003 Lyon (France); Dechelette, F. [CEA, DEN, DTN Cadarache, F-13108 Saint-Paul-lez-Durance (France); Prele, G. [EDF/SEPTEN, 12-14 avenue Dutrievoz, 69628 Villeurbane Cedex (France); Rodriguez, G. [CEA, DEN, DTN Cadarache, F-13108 Saint-Paul-lez-Durance (France)

2012-07-01

Within the framework of Sodium Fast Reactor development, innovative fuel assembly cleaning operations are investigated to meet the GEN IV goals of safety and of process development. One of the challenges is to mitigate the Sodium Water Reaction currently used in these processes. The potential applications of aqueous solutions of mineral salts (including the possibility of using redox chemical reactions) to mitigate the Sodium Water Reaction are considered in a first part and a new experimental bench, dedicated to this study, is described. Anhydrous alternative options based on Na/CO{sub 2} interaction are also presented. Then, in a second part, a functional study conducted on the cleaning pit is proposed. Based on experimental feedback, some calculations are carried out to estimate the sodium inventory on the fuel elements, and physical methods like hot inert gas sweeping to reduce this inventory are also presented. Finally, the implementation of these innovative solutions in cleaning pits is studied in regard to the expected performances. (authors)

Waste processing of chemical cleaning solutions

International Nuclear Information System (INIS)

Peters, G.A.

1991-01-01

This paper reports on chemical cleaning solutions containing high concentrations of organic chelating wastes that are difficult to reduce in volume using existing technology. Current methods for evaporating low-level radiative waste solutions often use high maintenance evaporators that can be costly and inefficient. The heat transfer surfaces of these evaporators are easily fouled, and their maintenance requires a significant labor investment. To address the volume reduction of spent, low-level radioactive, chelating-based chemical cleaning solutions, ECOSAFE Liquid Volume Reduction System (LVRS) has been developed. The LVRS is based on submerged combustion evaporator technology that was modified for treatment of low-level radiative liquid wastes. This system was developed in 1988 and was used to process 180,000 gallons of waste at Oconee Nuclear Station

Bubble size distribution analysis and control in high frequency ultrasonic cleaning processes

International Nuclear Information System (INIS)

Hauptmann, M; Struyf, H; Mertens, P; Heyns, M; Gendt, S De; Brems, S; Glorieux, C

2012-01-01

In the semiconductor industry, the ongoing down-scaling of nanoelectronic elements has lead to an increasing complexity of their fabrication. Hence, the individual fabrication processes become increasingly difficult to handle. To minimize cross-contamination, intermediate surface cleaning and preparation steps are inevitable parts of the semiconductor process chain. Here, one major challenge is the removal of residual nano-particulate contamination resulting from abrasive processes such as polishing and etching. In the past, physical cleaning techniques such as megasonic cleaning have been proposed as suitable solutions. However, the soaring fragility of the smallest structures is constraining the forces of the involved physical removal mechanisms. In the case of 'megasonic' cleaning –cleaning with ultrasound in the MHz-domain – the main cleaning action arises from strongly oscillating microbubbles which emerge from the periodically changing tensile strain in the cleaning liquid during sonication. These bubbles grow, oscillate and collapse due to a complex interplay of rectified diffusion, bubble coalescence, non-linear pulsation and the onset of shape instabilities. Hence, the resulting bubble size distribution does not remain static but alternates continuously. Only microbubbles in this distribution that show a high oscillatory response are responsible for the cleaning action. Therefore, the cleaning process efficiency can be improved by keeping the majority of bubbles around their resonance size. In this paper, we propose a method to control and characterize the bubble size distribution by means of 'pulsed' sonication and measurements of acoustic cavitation spectra, respectively. We show that the so-obtained bubble size distributions can be related to theoretical predictions of the oscillatory responses of and the onset of shape instabilities for the respective bubbles. We also propose a mechanism to explain the enhancement of both acoustic and cleaning

Process for cleaning radioactively contaminated metal surfaces

International Nuclear Information System (INIS)

Mihram, R.G.; Snyder, G.A.

1975-01-01

A process is described for removing radioactive scale from a ferrous metal surface, including the steps of initially preconditioning the surface by contacting it with an oxidizing solution (such as an aqueous solution of an alkali metal permanganate or hydrogen peroxide), then, after removal or decomposition of the oxidizing solution, the metallic surface is contacted with a cleaning solution which is a mixture of a mineral acid and a complexing agent (such as sulfuric acid and oxalic acid), and which preferably contains a corrosion inhibitor. A final step in the process is the treatment of the spent cleaning solution containing radioactive waste materials in solution by adding a reagent selected from the group consisting of calcium hydroxide or potassium permanganate and an alkali metal hydroxide to thereby form easily recovered metallic compounds containing substantially all of the dissolved metals and radioactivity. (auth)

Accuracy of the One-Stage and Two-Stage Impression Techniques: A Comparative Analysis

Directory of Open Access Journals (Sweden)

Ladan Jamshidy

2016-01-01

Full Text Available Introduction. One of the main steps of impression is the selection and preparation of an appropriate tray. Hence, the present study aimed to analyze and compare the accuracy of one- and two-stage impression techniques. Materials and Methods. A resin laboratory-made model, as the first molar, was prepared by standard method for full crowns with processed preparation finish line of 1 mm depth and convergence angle of 3-4°. Impression was made 20 times with one-stage technique and 20 times with two-stage technique using an appropriate tray. To measure the marginal gap, the distance between the restoration margin and preparation finish line of plaster dies was vertically determined in mid mesial, distal, buccal, and lingual (MDBL regions by a stereomicroscope using a standard method. Results. The results of independent test showed that the mean value of the marginal gap obtained by one-stage impression technique was higher than that of two-stage impression technique. Further, there was no significant difference between one- and two-stage impression techniques in mid buccal region, but a significant difference was reported between the two impression techniques in MDL regions and in general. Conclusion. The findings of the present study indicated higher accuracy for two-stage impression technique than for the one-stage impression technique.

Two-stage hepatectomy: who will not jump over the second hurdle?

Science.gov (United States)

Turrini, O; Ewald, J; Viret, F; Sarran, A; Goncalves, A; Delpero, J-R

2012-03-01

Two-stage hepatectomy uses compensatory liver regeneration after a first noncurative hepatectomy to enable a second curative resection in patients with bilobar colorectal liver metastasis (CLM). To determine the predictive factors of failure of two-stage hepatectomy. Between 2000 and 2010, 48 patients with irresectable CLM were eligible for two-stage hepatectomy. The planned strategy was a) cleaning of the left hepatic lobe (first hepatectomy), b) right portal vein embolisation and c) right hepatectomy (second hepatectomy). Six patients had occult CLM (n = 5) or extra-hepatic disease (n = 1), which was discovered during the first hepatectomy. Thus, 42 patients completed the first hepatectomy and underwent portal vein embolisation in order to receive the second hepatectomy. Eight patients did not undergo a second hepatectomy due to disease progression. Upon univariate analysis, two factors were identified that precluded patients from having the second hepatectomy: the combined resection of a primary tumour during the first hepatectomy (p = 0.01) and administration of chemotherapy between the two hepatectomies (p = 0.03). An independent association with impairment to perform the two-stage strategy was demonstrated by multivariate analysis for only the combined resection of the primary colorectal cancer during the first hepatectomy (p = 0.04). Due to the small number of patients and the absence of equivalent conclusions in other studies, we cannot recommend performance of an isolated colorectal resection prior to chemotherapy. However, resection of an asymptomatic primary tumour before chemotherapy should not be considered as an outdated procedure. Copyright © 2011 Elsevier Ltd. All rights reserved.

Clean coal technologies

International Nuclear Information System (INIS)

Aslanyan, G.S.

1993-01-01

According to the World Energy Council (WEC), at the beginning of the next century three main energy sources - coal, nuclear power and oil will have equal share in the world's total energy supply. This forecast is also valid for the USSR which possesses more than 40% of the world's coal resources and continuously increases its coal production (more than 700 million tons of coal are processed annually in the USSR). The stringent environmental regulations, coupled with the tendency to increase the use of coal are the reasons for developing different concepts for clean coal utilization. In this paper, the potential efficiency and environmental performance of different clean coal production cycles are considered, including technologies for coal clean-up at the pre-combustion stage, advanced clean combustion methods and flue gas cleaning systems. Integrated systems, such as combined gas-steam cycle and the pressurized fluidized bed boiler combined cycle, are also discussed. The Soviet National R and D program is studying new methods for coal utilization with high environmental performance. In this context, some basic research activities in the field of clean coal technology in the USSR are considered. Development of an efficient vortex combustor, a pressurized fluidized bed gasifier, advanced gas cleaning methods based on E-beam irradiation and plasma discharge, as well as new catalytic system, are are presented. In addition, implementation of technological innovations for retrofitting and re powering of existing power plants is discussed. (author)

Two-stage liquefaction of a Spanish subbituminous coal

Energy Technology Data Exchange (ETDEWEB)

Martinez, M.T.; Fernandez, I.; Benito, A.M.; Cebolla, V.; Miranda, J.L.; Oelert, H.H. (Instituto de Carboquimica, Zaragoza (Spain))

1993-05-01

A Spanish subbituminous coal has been processed in two-stage liquefaction in a non-integrated process. The first-stage coal liquefaction has been carried out in a continuous pilot plant in Germany at Clausthal Technical University at 400[degree]C, 20 MPa hydrogen pressure and anthracene oil as solvent. The second-stage coal liquefaction has been performed in continuous operation in a hydroprocessing unit at the Instituto de Carboquimica at 450[degree]C and 10 MPa hydrogen pressure, with two commercial catalysts: Harshaw HT-400E (Co-Mo/Al[sub 2]O[sub 3]) and HT-500E (Ni-Mo/Al[sub 2]O[sub 3]). The total conversion for the first-stage coal liquefaction was 75.41 wt% (coal d.a.f.), being 3.79 wt% gases, 2.58 wt% primary condensate and 69.04 wt% heavy liquids. The heteroatoms removal for the second-stage liquefaction was 97-99 wt% of S, 85-87 wt% of N and 93-100 wt% of O. The hydroprocessed liquids have about 70% of compounds with boiling point below 350[degree]C, and meet the sulphur and nitrogen specifications for refinery feedstocks. Liquids from two-stage coal liquefaction have been distilled, and the naphtha, kerosene and diesel fractions obtained have been characterized. 39 refs., 3 figs., 8 tabs.

Comparison of single-stage and temperature-phased two-stage anaerobic digestion of oily food waste

International Nuclear Information System (INIS)

Wu, Li-Jie; Kobayashi, Takuro; Li, Yu-You; Xu, Kai-Qin

2015-01-01

Highlights: • A single-stage and two two-stage anaerobic systems were synchronously operated. • Similar methane production 0.44 L/g VS_a_d_d_e_d from oily food waste was achieved. • The first stage of the two-stage process became inefficient due to serious pH drop. • Recycle favored the hythan production in the two-stage digestion. • The conversion of unsaturated fatty acids was enhanced by recycle introduction. - Abstract: Anaerobic digestion is an effective technology to recover energy from oily food waste. A single-stage system and temperature-phased two-stage systems with and without recycle for anaerobic digestion of oily food waste were constructed to compare the operation performances. The synchronous operation indicated the similar ability to produce methane in the three systems, with a methane yield of 0.44 L/g VS_a_d_d_e_d. The pH drop to less than 4.0 in the first stage of two-stage system without recycle resulted in poor hydrolysis, and methane or hydrogen was not produced in this stage. Alkalinity supplement from the second stage of two-stage system with recycle improved pH in the first stage to 5.4. Consequently, 35.3% of the particulate COD in the influent was reduced in the first stage of two-stage system with recycle according to a COD mass balance, and hydrogen was produced with a percentage of 31.7%, accordingly. Similar solids and organic matter were removed in the single-stage system and two-stage system without recycle. More lipid degradation and the conversion of long-chain fatty acids were achieved in the single-stage system. Recycling was proved to be effective in promoting the conversion of unsaturated long-chain fatty acids into saturated fatty acids in the two-stage system.

Two-stage precipitation of plutonium trifluoride

International Nuclear Information System (INIS)

Luerkens, D.W.

1984-04-01

Plutonium trifluoride was precipitated using a two-stage precipitation system. A series of precipitation experiments identified the significant process variables affecting precipitate characteristics. A mathematical precipitation model was developed which was based on the formation of plutonium fluoride complexes. The precipitation model relates all process variables, in a single equation, to a single parameter that can be used to control particle characteristics

PWR steam generator chemical cleaning. Phase I: solvent and process development. Volume II

International Nuclear Information System (INIS)

Larrick, A.P.; Paasch, R.A.; Hall, T.M.; Schneidmiller, D.

1979-01-01

A program to demonstrate chemical cleaning methods for removing magnetite corrosion products from the annuli between steam generator tubes and the tube support plates in vertical U-tube steam generators is described. These corrosion products have caused steam generator tube ''denting'' and in some cases have caused tube failures and support plate cracking in several PWR generating plants. Laboratory studies were performed to develop a chemical cleaning solvent and application process for demonstration cleaning of the Indian Point Unit 2 steam generators. The chemical cleaning solvent and application process were successfully pilot-tested by cleaning the secondary side of one of the Indian Point Unit 1 steam generators. Although the Indian Point Unit 1 steam generators do not have a tube denting problem, the pilot test provided for testing of the solvent and process using much of the same equipment and facilities that would be used for the Indian Point Unit 2 demonstration cleaning. The chemical solvent selected for the pilot test was an inhibited 3% citric acid-3% ascorbic acid solution. The application process, injection into the steam generator through the boiler blowdown system and agitation by nitrogen sparging, was tested in a nuclear environment and with corrosion products formed during years of steam generator operation at power. The test demonstrated that the magnetite corrosion products in simulated tube-to-tube support plate annuli can be removed by chemical cleaning; that corrosion resulting from the cleaning is not excessive; and that steam generator cleaning can be accomplished with acceptable levels of radiation exposure to personnel

Cleaning the feed-water pipeline internal surfaces

International Nuclear Information System (INIS)

Podkopaev, V.A.

1984-01-01

The procedure of cleaning the feed-water pipeline internal surfaces at the Chernobylsk-4 power unit is described. Cleaning was conducted in five stages. Pipelines were cleaned from mechanical impurities at the first stage. At the second stage the pipelines were washing by water heated up to 80 deg C. At the third stage nitric acid was added to 95-100 deg C water the acid concentration in the circuit = 60 mg/l, purification period = 14 h. At the fourth stage hydrogen peroxide was added to the circuit at 95-100 deg C (the solution concentration was equal to 5-6 mg/l, the solution stayed in the circuit for 1 h 20 min). At the fifth stage sodium nitrite concentrated to 20 mg/l was introduced to the circuit in 75 minutes; this promoted strengthening of the oxide layer in the circuit on the base of nitric acid and hydrogen peroxide. Data on the water acidity in the circuit, water electric conductivity and iron concentration after the fourth stage and on completion of the circuit cleaning are presented. The described method of cleaning enables to save scarce reagents and use cheaper ones

Cleaning the feed-water pipeline internal surfaces

Energy Technology Data Exchange (ETDEWEB)

Podkopaev, V.A.

1984-12-01

The procedure of cleaning the feed-water pipeline internal surfaces at the Chernobylsk-4 power unit is described. Cleaning was conducted in five stages. Pipelines were cleaned from mechanical impurities at the first stage. At the second stage the pipelines were washed by water heated up to 80 deg C. At the third stage nitric acid was added to 95-100 deg C water with the acid concentration in the circuit = 60 mg/l, purification period = 14 h. At the fourth stage hydrogen peroxide was added to the circuit at 95-100 deg C (the solution concentration was equal to 5-6 mg/l, the solution stayed in the circuit for 1 h 20 min). At the fifth stage sodium nitrite concentrated to 20 mg/l was introduced to the circuit in 75 minutes; this promoted strengthening of the oxide layer in the circuit on the base of nitric acid and hydrogen peroxide. Data on the water acidity in the circuit, water electric conductivity and iron concentration after the fourth stage and on completion of the circuit cleaning are presented. The described method of cleaning enables to save scarce reagents and use cheaper ones.

A new cleaning process for the metallic contaminants on a post-CMP wafer's surface

International Nuclear Information System (INIS)

Gao Baohong; Liu Yuling; Wang Chenwei; Wang Shengli; Zhou Qiang; Tan Baimei; Zhu Yadong

2010-01-01

This paper presents a new cleaning process using boron-doped diamond (BDD) film anode electrochemical oxidation for metallic contaminants on polished silicon wafer surfaces. The BDD film anode electrochemical oxidation can efficiently prepare pyrophosphate peroxide, pyrophosphate peroxide can oxidize organic contaminants, and pyrophosphate peroxide is deoxidized into pyrophosphate. Pyrophosphate, a good complexing agent, can form a metal complex, which is a structure consisting of a copper ion, bonded to a surrounding array of two pyrophosphate anions. Three polished wafers were immersed in the 0.01 mol/L CuSO 4 solution for 2 h in order to make comparative experiments. The first one was cleaned by pyrophosphate peroxide, the second by RCA (Radio Corporation of America) cleaning, and the third by deionized (DI) water. The XPS measurement result shows that the metallic contaminants on wafers cleaned by the RCA method and by pyrophosphate peroxide is less than the XPS detection limits of 1 ppm. And the wafer's surface cleaned by pyrophosphate peroxide is more efficient in removing organic carbon residues than RCA cleaning. Therefore, BDD film anode electrochemical oxidation can be used for microelectronics cleaning, and it can effectively remove organic contaminants and metallic contaminants in one step. It also achieves energy saving and environmental protection. (semiconductor technology)

Bench-scale testing of a micronized magnetite, fine-coal cleaning process

Energy Technology Data Exchange (ETDEWEB)

Suardini, P.J. [Custom Coals, International, Pittsburgh, PA (United States)

1995-11-01

Custom Coals, International has installed and is presently testing a 500 lb/hr. micronized-magnetite, fine-coal cleaning circuit at PETC`s Process Research Facility (PRF). The cost-shared project was awarded as part of the Coal Preparation Program`s, High Efficiency Preparation Subprogram. The project includes design, construction, testing, and decommissioning of a fully-integrated, bench-scale circuit, complete with feed coal classification to remove the minus 30 micron slimes, dense medium cycloning of the 300 by 30 micron feed coal using a nominal minus 10 micron size magnetite medium, and medium recovery using drain and rinse screens and various stages and types of magnetic separators. This paper describes the project circuit and goals, including a description of the current project status and the sources of coal and magnetite which are being tested.

Clean Coal Diesel Demonstration Project

Energy Technology Data Exchange (ETDEWEB)

Robert Wilson

2006-10-31

A Clean Coal Diesel project was undertaken to demonstrate a new Clean Coal Technology that offers technical, economic and environmental advantages over conventional power generating methods. This innovative technology (developed to the prototype stage in an earlier DOE project completed in 1992) enables utilization of pre-processed clean coal fuel in large-bore, medium-speed, diesel engines. The diesel engines are conventional modern engines in many respects, except they are specially fitted with hardened parts to be compatible with the traces of abrasive ash in the coal-slurry fuel. Industrial and Municipal power generating applications in the 10 to 100 megawatt size range are the target applications. There are hundreds of such reciprocating engine power-plants operating throughout the world today on natural gas and/or heavy fuel oil.

Meta-analysis of Gaussian individual patient data: Two-stage or not two-stage?

Science.gov (United States)

Morris, Tim P; Fisher, David J; Kenward, Michael G; Carpenter, James R

2018-04-30

Quantitative evidence synthesis through meta-analysis is central to evidence-based medicine. For well-documented reasons, the meta-analysis of individual patient data is held in higher regard than aggregate data. With access to individual patient data, the analysis is not restricted to a "two-stage" approach (combining estimates and standard errors) but can estimate parameters of interest by fitting a single model to all of the data, a so-called "one-stage" analysis. There has been debate about the merits of one- and two-stage analysis. Arguments for one-stage analysis have typically noted that a wider range of models can be fitted and overall estimates may be more precise. The two-stage side has emphasised that the models that can be fitted in two stages are sufficient to answer the relevant questions, with less scope for mistakes because there are fewer modelling choices to be made in the two-stage approach. For Gaussian data, we consider the statistical arguments for flexibility and precision in small-sample settings. Regarding flexibility, several of the models that can be fitted only in one stage may not be of serious interest to most meta-analysis practitioners. Regarding precision, we consider fixed- and random-effects meta-analysis and see that, for a model making certain assumptions, the number of stages used to fit this model is irrelevant; the precision will be approximately equal. Meta-analysts should choose modelling assumptions carefully. Sometimes relevant models can only be fitted in one stage. Otherwise, meta-analysts are free to use whichever procedure is most convenient to fit the identified model. © 2018 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

Financing clean energy market creation. Clean energy ventures, venture capitalists and other investors

Energy Technology Data Exchange (ETDEWEB)

Teppo, T. [Helsinki Univ. of Technology, Espoo (Finland). Development and Management in Industry

2006-07-01

Many factors have emerged for change towards cleaner and more efficient technologies and services: climate change, increasing oil demands, and rising living standards in many parts of the world are putting an ever-increasing strain on the environment. Recently, these drivers have fueled the formation of a clean energy venture capital market where both independent venture capitalists (VCs) and corporate venture capitalists (CVCs) have invested in clean energy start-ups. Financing of clean energy market creation is the focus of this dissertation. The dissertation contributes to several bodies of literature in the area of entrepreneurship, new industry creation, corporate venturing, and venture capital research. The dissertation uses a grounded theory approach. The study is guided by three data collection approaches with an emphasis on the first two. First, interviews with European and North American VC and CVC firms that have invested in the clean energy sector were carried out. Second, a clean energy venture financing survey that consisted of qualitative, essay-format questions and some quantitative questions was carried out. Third, interviews with clean energy stakeholders were carried out in order to gain a better understanding of the emerging sector. The research results consist of three main findings. First, the research results suggest that clean energy ventures face the following three main entrepreneurial challenges: financing, market education, and growth management. A further study of three clean energy industry categories revealed additional challenges that varied according to the industry development stage. Second, the results demonstrate that, from a venture capitalist perspective, clean energy venture risk characteristics can be divided into two groups: generally recognized risk characteristics and cognitive risk characteristics. The identified generally recognized risk characteristics were market demand and adaptation, incompatibility with the VC model

Sensory shelf life estimation of minimally processed lettuce considering two stages of consumers' decision-making process.

Science.gov (United States)

Ares, Gastón; Giménez, Ana; Gámbaro, Adriana

2008-01-01

The aim of the present work was to study the influence of context, particularly the stage of the decision-making process (purchase vs consumption stage), on sensory shelf life of minimally processed lettuce. Leaves of butterhead lettuce were placed in common polypropylene bags and stored at 5, 10 and 15 degrees C. Periodically, a panel of six assessors evaluated the appearance of the samples, and a panel of 40 consumers evaluated their appearance and answered "yes" or "no" to the questions: "Imagine you are in a supermarket, you want to buy a minimally processed lettuce, and you find a package of lettuce with leaves like this, would you normally buy it?" and "Imagine you have this leaf of lettuce stored in your refrigerator, would you normally consume it?". Survival analysis was used to calculate the shelf lives of minimally processed lettuce, considering both decision-making stages. Shelf lives estimated considering rejection to purchase were significantly lower than those estimated considering rejection to consume. Therefore, in order to be conservative and assure the products' quality, shelf life should be estimated considering consumers' rejection to purchase instead of rejection to consume, as traditionally has been done. On the other hand, results from logistic regressions of consumers' rejection percentage as a function of the evaluated appearance attributes suggested that consumers considered them differently while deciding whether to purchase or to consume minimally processed lettuce.

Hot fuel gas dedusting after sorbent-based gas cleaning

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-07-01

Advanced power generation technologies, such as Air Blown Gasification Cycle (ABGC), require gas cleaning at high temperatures in order to meet environmental standards and to achieve high thermal efficiencies. The primary hot gas filtration process, which removes particulates from the cooled raw fuel gas at up to 600{degree}C is the first stage of gas cleaning prior to desulphurization and ammonia removal processes. The dust concentration in the fuel gas downstream of the sorbent processes would be much lower than for the hot gas filtration stage and would have a lower sulphur content and possibly reduced chlorine concentration. The main aim of this project is to define the requirements for a hot gas filter for dedusting fuel gas under these conditions, and to identify a substantially simpler and more cost effective solution using ceramic or metal barrier filters.

7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

Science.gov (United States)

2010-01-01

... quantities; seed for cleaning or processing. (a) In the case of seed in bulk, the information required under... seeds. (b) Seed consigned to a seed cleaning or processing establishment, for cleaning or processing for... pertaining to such seed show that it is “Seed for processing,” or, if the seed is in containers and in...

Steam generators secondary side chemical cleaning at Point Lepreau using the Siemen's high temperature process

International Nuclear Information System (INIS)

Verma, K.; MacNeil, C.; Odar, S.

1996-01-01

The secondary sides of all four steam generators at the Point Lepreau Nuclear Generating Stations were cleaned during the 1995 annual outage run-down using the Siemens high temperature chemical cleaning process. Traditionally all secondary side chemical cleaning exercises in CANDU as well as the other nuclear power stations in North America have been conducted using a process developed in conjunction with the Electric Power Research Institute (EPRI). The Siemens high temperature process was applied for the first time in North America at the Point Lepreau Nuclear Generating Station (PLGS). The paper discusses experiences related to the pre and post award chemical cleaning activities, chemical cleaning application, post cleaning inspection results and waste handling activities. (author)

Energized CO{sub 2} dry ice blast cleaning firmly grounded in the Canadian electrical industry

Energy Technology Data Exchange (ETDEWEB)

Lindsay, K.

1999-02-01

Development and use of energized carbon dioxide dry ice blast technology for cleaning electrical distribution system components by Oakville Hydro and Milton Hydro (both in Ontario) is discussed. The technology was developed by Alpheus Cleaning Technologies of California and Puget Sound Power and Light Company after a two-year study that commenced in 1991, and has been supplied in Canada by Wickens Industrial Ltd., since 1993 for cleaning various industrial and non-energized electrical applications in the automotive, printing , food processing and other manufacturing industries and hydro generating facilities. The unique cleaning dynamics of this technology allow for the removal of contaminants that are much more stubborn than those encountered in pad-mounted switchgear and other electrical apparatus. Dry ice pellets, by expanding to 400 times their solid state on impact, create a flushing action that helps to remove contaminants. No grit or solvents are required and the process is non-toxic. In using the process workers wear fire retardant clothing, 40 kV-Class 4 rubber gloves and full face shields. Dielectric tests are performed routinely to confirm the dielectric integrity of the spray wand components. A two stage inspection/trouble report is completed on every job. Use of this technology eliminates power interruptions to customers, improves system reliability and safety, reduces cleaning time to a minimum, and eliminated the need for reclamation of grit or solvent containment.

7 CFR 361.8 - Cleaning of imported seed and processing of certain Canadian-origin screenings.

Science.gov (United States)

2010-01-01

... 7 Agriculture 5 2010-01-01 2010-01-01 false Cleaning of imported seed and processing of certain... SCREENINGS UNDER THE FEDERAL SEED ACT § 361.8 Cleaning of imported seed and processing of certain Canadian... compliance agreement for the cleaning of imported seed or processing of otherwise prohibited screenings from...

Service water chemical cleaning at River Bend gets results

International Nuclear Information System (INIS)

Brice, T.O.; Glover, W.A.

1994-01-01

The largest known Service Water System (SWS) chemical cleaning ever performed at a nuclear plant was successfully completed at, River Bend Station. Corrosion product buildup was observed during system inspections in the first operating cycle and the first refueling outage in 1987. Under deposit corrosion was followed with microbiologically influenced corrosion (MIC) occurring as a later stage under deposits. The heavy corrosion caused blockage of heat exchanger tubes, fouling of valve seats, and general flow blockage throughout the system. Various options were evaluated for restoring the SWS back to an acceptable long term operating condition. The large scale chemical cleaning performed arrested the corrosion by removing the deposits down to the bare metal surfaces and leaving behind a protective passivation layer. After the cleaning, the open recirculating SWS was converted to a closed system. The implementation of a molybdate/nitrate water treatment program with a copper corrosion inhibitor maintained at a high pH (8.5--10.5) has significantly reduced corrosion rates in the closed system. This should extend the life of the SWS piping for the remaining life of the plant. Several field tests were conducted to qualify the process and demonstrate its ability to achieve acceptable cleaning results prior to being used on a larger scale. In the summer of 1992, temporary and permanent modifications were installed to divide the SWS into two separate cleaning loops for the system wide cleaning. The SWS chemical was successfully performed and completed on schedule during the fourth refueling outage. Post cleaning inspections at various locations throughout the Service Water System showed the process to be very effective at complete deposit removal

Audiovisual integration in speech perception: a multi-stage process

DEFF Research Database (Denmark)

Eskelund, Kasper; Tuomainen, Jyrki; Andersen, Tobias

2011-01-01

investigate whether the integration of auditory and visual speech observed in these two audiovisual integration effects are specific traits of speech perception. We further ask whether audiovisual integration is undertaken in a single processing stage or multiple processing stages....

Alternatives to Organic Solvents in Industrial Cleaning Processes

DEFF Research Database (Denmark)

Jacobsen, Thomas

1998-01-01

To control chemical hazards in work places, substitution of harmful substances with less harmful or non-toxic products is now a method used in many countries and in many companies. It has previously been demonstrated that it is desirable and possible to use non-volatile, low-toxic vegetable...... cleaning agents in offset printing companies instead of volatile, toxic organic solvents. The present study is based on a project with the aim of defining other industrial processes, where organic solvents used for cleaning or degreasing can be replaced by non-volatile, low-toxic products, which are based...... on esters from fatty acids of vegetable origin (vegetable esters - VE).The study indicates that industrial cleaning/degreasing with organic solvents may be substituted with VEs on metal surfaces and on some coated surfaces, in manufacture of paints and inks, use of paints, use of inks (printing), metal...

Manual cleaning of hospital mattresses: an observational study comparing high- and low-resource settings.

Science.gov (United States)

Hopman, J; Hakizimana, B; Meintjes, W A J; Nillessen, M; de Both, E; Voss, A; Mehtar, S

2016-01-01

Hospital-associated infections (HAIs) are more frequently encountered in low- than in high-resource settings. There is a need to identify and implement feasible and sustainable approaches to strengthen HAI prevention in low-resource settings. To evaluate the biological contamination of routinely cleaned mattresses in both high- and low-resource settings. In this two-stage observational study, routine manual bed cleaning was evaluated at two university hospitals using adenosine triphosphate (ATP). Standardized training of cleaning personnel was achieved in both high- and low-resource settings. Qualitative analysis of the cleaning process was performed to identify predictors of cleaning outcome in low-resource settings. Mattresses in low-resource settings were highly contaminated prior to cleaning. Cleaning significantly reduced biological contamination of mattresses in low-resource settings (P cleaning in both the high- and low-resource settings seemed comparable. Cleaning with appropriate type of cleaning materials reduced the contamination of mattresses adequately. Predictors for mattresses that remained contaminated in a low-resource setting included: type of product used, type of ward, training, and the level of contamination prior to cleaning. In low-resource settings mattresses were highly contaminated as noted by ATP levels. Routine manual cleaning by trained staff can be as effective in a low-resource setting as in a high-resource setting. We recommend a multi-modal cleaning strategy that consists of training of domestic services staff, availability of adequate time to clean beds between patients, and application of the correct type of cleaning products. Copyright © 2015 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Low-temperature wafer direct bonding of silicon and quartz glass by a two-step wet chemical surface cleaning

Science.gov (United States)

Wang, Chenxi; Xu, Jikai; Zeng, Xiaorun; Tian, Yanhong; Wang, Chunqing; Suga, Tadatomo

2018-02-01

We demonstrate a facile bonding process for combining silicon and quartz glass wafers by a two-step wet chemical surface cleaning. After a post-annealing at 200 °C, strong bonding interfaces with no defects or microcracks were obtained. On the basis of the detailed surface and bonding interface characterizations, the bonding mechanism was explored and discussed. The amino groups terminated on the cleaned surfaces might contribute to the bonding strength enhancement during the annealing. This cost-effective bonding process has great potentials for silicon- and glass-based heterogeneous integrations without requiring a vacuum system.

2000 Annual report NATO/CCMS Pilot Study, Clean Products and Processes (Phase I)

DEFF Research Database (Denmark)

Wenzel, Henrik; Molin, Christine; Hauschild, Michael Zwicky

2001-01-01

The NATO/Committee on the Challenges of Modern Society third Pilot Study meeting on Clean Products and Processes was held in Copenhagen, Denmark on May 7-12, 2000. This meeting maintained the momentum generated during the of the first two years of the pilot study, focusing on progress made on sev...... homepage....

Substitution of Organic Solvents in Selected Industrial Cleaning Processes

DEFF Research Database (Denmark)

Jacobsen, Thomas; Rasmussen, Pia Brunn

1997-01-01

Volatile organic solvents (VOC)are becoming increasingly unwanted in industrial processes. Substitution of VOC with non-volatile, low-toxic compounds is a possibility to reduce VOC-use. It has been successfully demonstrated, that organic solvents used in cleaning processes in sheet offset printing...

Tests of an environmental and personnel safe cleaning process for BNL accelerator and storage ring components

International Nuclear Information System (INIS)

Foerster, C.L.; Lanni, C.; Lee, R.; Mitchell, G.; Quade, W.

1996-10-01

A large measure of the successful operation of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL) for over a decade can be attributed to the cleaning of its UHV components during and after construction. A new UHV cleaning process, which had to be environmentally and personnel safe, was needed to replace the harsh, unfriendly process which was still in use. Dow Advanced Cleaning Systems was contracted to develop a replacement process without the use of harsh chemicals and which must clean vacuum surfaces as well as the existing process. Acceptance of the replacement process was primarily based on Photon Stimulated Desorption (PSD) measurements of beam tube samples run on NSLS beam line U10B. One meter long beam tube samples were fabricated from aluminum, 304 stainless steel and oxygen free copper. Initially, coupon samples were cleaned and passed preliminary testing for the proposed process. Next, beam tube samples of each material were cleaned, and the PSD measured on beam line U10B using white light with a critical energy of 487 ev. Prior to cleaning, the samples were contaminated with a mixture of cutting oils, lubricants, vacuum oils and vacuum grease. The contaminated samples were then baked. Samples of each material were also cleaned with the existing process after the same preparation. Beam tube samples were exposed to between 10 22 and 10 23 photons per meter for a PSD measurement. Desorption yields for H 2 , CO, CO 2 , CH 4 and H 2 O are reported for both the existing cleaning and for the replacement cleaning process. Preliminary data, residual gas scans, and PSD results are given and discussed. The new process is also compared with new cleaning methods developed in other laboratories

Effectiveness of bone cleaning process using chemical and entomology approaches: time and cost.

Science.gov (United States)

Lai, Poh Soon; Khoo, Lay See; Mohd Hilmi, Saidin; Ahmad Hafizam, Hasmi; Mohd Shah, Mahmood; Nurliza, Abdullah; Nazni, Wasi Ahmad

2015-08-01

Skeletal examination is an important aspect of forensic pathology practice, requiring effective bone cleaning with minimal artefact. This study was conducted to compare between chemical and entomology methods of bone cleaning. Ten subjects between 20 and 40 years old who underwent uncomplicated medico-legal autopsies at the Institute of Forensic Medicine Malaysia were randomly chosen for this descriptive cross sectional study. The sternum bone was divided into 4 parts, each part subjected to a different cleaning method, being two chemical approaches i.e. laundry detergent and a combination of 6% hydrogen peroxide and powder sodium bicarbonate and two entomology approaches using 2nd instar maggots of Chrysomyia rufifacies and Ophyra spinigera. A scoring system for grading the outcome of cleaning was used. The effectiveness of the methods was evaluated based on average weight reduction per day and median number of days to achieve the average score of less than 1.5 within 12 days of the bone cleaning process. Using maggots was the most time-effective and costeffective method, achieving an average weight reduction of 1.4 gm per day, a median of 11.3 days to achieve the desired score and an average cost of MYR 4.10 per case to reach the desired score within 12 days. This conclusion was supported by blind validation by forensic specialists achieving a 77.8% preference for maggots. Emission scanning electron microscopy evaluation also revealed that maggots especially Chrysomyia rufifacies preserved the original condition of the bones better allowing improved elucidation of bone injuries in future real cases.

Mathematical modeling of a continuous alcoholic fermentation process in a two-stage tower reactor cascade with flocculating yeast recycle.

Science.gov (United States)

de Oliveira, Samuel Conceição; de Castro, Heizir Ferreira; Visconti, Alexandre Eliseu Stourdze; Giudici, Reinaldo

2015-03-01

Experiments of continuous alcoholic fermentation of sugarcane juice with flocculating yeast recycle were conducted in a system of two 0.22-L tower bioreactors in series, operated at a range of dilution rates (D 1 = D 2 = 0.27-0.95 h(-1)), constant recycle ratio (α = F R /F = 4.0) and a sugar concentration in the feed stream (S 0) around 150 g/L. The data obtained in these experimental conditions were used to adjust the parameters of a mathematical model previously developed for the single-stage process. This model considers each of the tower bioreactors as a perfectly mixed continuous reactor and the kinetics of cell growth and product formation takes into account the limitation by substrate and the inhibition by ethanol and biomass, as well as the substrate consumption for cellular maintenance. The model predictions agreed satisfactorily with the measurements taken in both stages of the cascade. The major differences with respect to the kinetic parameters previously estimated for a single-stage system were observed for the maximum specific growth rate, for the inhibition constants of cell growth and for the specific rate of substrate consumption for cell maintenance. Mathematical models were validated and used to simulate alternative operating conditions as well as to analyze the performance of the two-stage process against that of the single-stage process.

Development of Statistical Process Control Methodology for an Environmentally Compliant Surface Cleaning Process in a Bonding Laboratory

Science.gov (United States)

Hutchens, Dale E.; Doan, Patrick A.; Boothe, Richard E.

1997-01-01

Bonding labs at both MSFC and the northern Utah production plant prepare bond test specimens which simulate or witness the production of NASA's Reusable Solid Rocket Motor (RSRM). The current process for preparing the bonding surfaces employs 1,1,1-trichloroethane vapor degreasing, which simulates the current RSRM process. Government regulations (e.g., the 1990 Amendments to the Clean Air Act) have mandated a production phase-out of a number of ozone depleting compounds (ODC) including 1,1,1-trichloroethane. In order to comply with these regulations, the RSRM Program is qualifying a spray-in-air (SIA) precision cleaning process using Brulin 1990, an aqueous blend of surfactants. Accordingly, surface preparation prior to bonding process simulation test specimens must reflect the new production cleaning process. The Bonding Lab Statistical Process Control (SPC) program monitors the progress of the lab and its capabilities, as well as certifies the bonding technicians, by periodically preparing D6AC steel tensile adhesion panels with EA-91 3NA epoxy adhesive using a standardized process. SPC methods are then used to ensure the process is statistically in control, thus producing reliable data for bonding studies, and identify any problems which might develop. Since the specimen cleaning process is being changed, new SPC limits must be established. This report summarizes side-by-side testing of D6AC steel tensile adhesion witness panels and tapered double cantilevered beams (TDCBs) using both the current baseline vapor degreasing process and a lab-scale spray-in-air process. A Proceco 26 inches Typhoon dishwasher cleaned both tensile adhesion witness panels and TDCBs in a process which simulates the new production process. The tests were performed six times during 1995, subsequent statistical analysis of the data established new upper control limits (UCL) and lower control limits (LCL). The data also demonstrated that the new process was equivalent to the vapor

Textile Dry Cleaning Using Carbon Dioxide : Process, Apparatus and Mechanical Action

NARCIS (Netherlands)

Sutanto, S.

2014-01-01

Fabrics that are sensitive to water, may wrinkle or shrink when washed in regular washing machines and are usually cleaned by professional dry cleaners. Dry cleaning is a process of removing soils from substrate, in this case textile, using a non-aqueous solvent. The most common solvent in

ANALYSIS ON TECHNOLOGICAL PROCESSES CLEANING OIL PIPELINES

Directory of Open Access Journals (Sweden)

Mariana PǍTRAŞCU

2015-05-01

Full Text Available In this paper the researches are presented concerning the technological processes of oil pipelines.We know several technologies and materials used for cleaning the sludge deposits, iron and manganese oxides, dross, stone, etc.de on the inner walls of drinking water pipes or industries.For the oil industry, methods of removal of waste materials and waste pipes and liquid and gas transport networks are operations known long, tedious and expensive. The main methods and associated problems can be summarized as follows: 1 Blowing with compressed air.2 manual or mechanical brushing, sanding with water or dry.3 Wash with water jet of high pressure, solvent or chemical solution to remove the stone and hard deposits.4 The combined methods of cleaning machines that use water jets, cutters, chains, rotary heads cutters, etc.

Two-Stage Variable Sample-Rate Conversion System

Science.gov (United States)

Tkacenko, Andre

2009-01-01

A two-stage variable sample-rate conversion (SRC) system has been pro posed as part of a digital signal-processing system in a digital com munication radio receiver that utilizes a variety of data rates. The proposed system would be used as an interface between (1) an analog- todigital converter used in the front end of the receiver to sample an intermediatefrequency signal at a fixed input rate and (2) digita lly implemented tracking loops in subsequent stages that operate at v arious sample rates that are generally lower than the input sample r ate. This Two-Stage System would be capable of converting from an input sample rate to a desired lower output sample rate that could be var iable and not necessarily a rational fraction of the input rate.

One-stage and two-stage penile buccal mucosa urethroplasty

Directory of Open Access Journals (Sweden)

G. Barbagli

2016-03-01

Full Text Available The paper provides the reader with the detailed description of current techniques of one-stage and two-stage penile buccal mucosa urethroplasty. The paper provides the reader with the preoperative patient evaluation paying attention to the use of diagnostic tools. The one-stage penile urethroplasty using buccal mucosa graft with the application of glue is preliminary showed and discussed. Two-stage penile urethroplasty is then reported. A detailed description of first-stage urethroplasty according Johanson technique is reported. A second-stage urethroplasty using buccal mucosa graft and glue is presented. Finally postoperative course and follow-up are addressed.

Minimizing the Makespan for a Two-Stage Three-Machine Assembly Flow Shop Problem with the Sum-of-Processing-Time Based Learning Effect

Directory of Open Access Journals (Sweden)

Win-Chin Lin

2018-01-01

Full Text Available Two-stage production process and its applications appear in many production environments. Job processing times are usually assumed to be constant throughout the process. In fact, the learning effect accrued from repetitive work experiences, which leads to the reduction of actual job processing times, indeed exists in many production environments. However, the issue of learning effect is rarely addressed in solving a two-stage assembly scheduling problem. Motivated by this observation, the author studies a two-stage three-machine assembly flow shop problem with a learning effect based on sum of the processing times of already processed jobs to minimize the makespan criterion. Because this problem is proved to be NP-hard, a branch-and-bound method embedded with some developed dominance propositions and a lower bound is employed to search for optimal solutions. A cloud theory-based simulated annealing (CSA algorithm and an iterated greedy (IG algorithm with four different local search methods are used to find near-optimal solutions for small and large number of jobs. The performances of adopted algorithms are subsequently compared through computational experiments and nonparametric statistical analyses, including the Kruskal–Wallis test and a multiple comparison procedure.

Experiments for Multi-Stage Processes

DEFF Research Database (Denmark)

Tyssedal, John; Kulahci, Murat

2015-01-01

Multi-stage processes are very common in both process and manufacturing industries. In this article we present a methodology for designing experiments for multi-stage processes. Typically in these situations the design is expected to involve many factors from different stages. To minimize...... the required number of experimental runs, we suggest using mirror image pairs of experiments at each stage following the first. As the design criterion, we consider their projectivity and mainly focus on projectivity 3 designs. We provide the methodology for generating these designs for processes with any...

[Importance of cleaning and disinfection of critical surfaces in dental health services. Impact of an intervention program].

Science.gov (United States)

Véliz, Elena; Vergara, Teresa; Pearcy, Mercedes; Dabanch, Jeannette

Introduction Dental care has become a challenge for healthcare associated infection prevention programs, since the environment, within other factors, plays an important role in the transmission chain. Materials and Methods An intervention program was designed for the Dental Unit of Hospital Militar de Santiago, between years 2014 and 2015. The program contemplated 3 stages: diagnostic, intervention and evaluation stage. Objective To improve the safety of critical surfaces involved in dental healthcare. Results During the diagnostic stage, the cleaning and disinfection process was found to be deficient. The most contaminated critical surface was the instrument holder unit, then the clean area and lamp handle. The surfaces that significantly reduced their contamination, after the intervention, were the clean area and the instrument carrier unit. Conclusion Training in the processes of cleaning and disinfecting surfaces and dental equipment is one of the cost-effective strategies in preventing healthcare-associated infections (HCAI), with simple and easy-to-apply methods.

Effect of two-stage sintering process on microstructure and mechanical properties of ODS tungsten heavy alloy

Energy Technology Data Exchange (ETDEWEB)

Lee, Kyong H. [Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 373-1 Kusong-dong, Yusong-gu, Taejon 305-701 (Korea, Republic of); Cha, Seung I. [International Center for Young Scientists, National Institute for Materials Science 1-1, Namiki, Tsukuba 305-0044 (Japan); Ryu, Ho J. [DUPIC, Korea Atomic Energy Research Institute, 150 Deokjin-dong, Yusong-gu, Taejon 305-353 (Korea, Republic of); Hong, Soon H. [Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 373-1 Kusong-dong, Yusong-gu, Taejon 305-701 (Korea, Republic of)], E-mail: shhong@kaist.ac.kr

2007-06-15

Oxide dispersion strengthened (ODS) tungsten heavy alloys have been considered as promising candidates for advanced kinetic energy penetrator due to their characteristic fracture mode compared to conventional tungsten heavy alloy. In order to obtain high relative density, the ODS tungsten heavy alloy needs to be sintered at higher temperature for longer time, however, induces growth of tungsten grains. Therefore, it is very difficult to obtain controlled microstructure of ODS tungsten heavy alloy having fine tungsten grains with full densification. In this study, two-stage sintering process, consisted of primary solid-state sintering and followed by secondary liquid phase sintering, was introduced for ODS tungsten heavy alloys. The mechanically alloyed 94W-4.56Ni-1.14Fe-0.3Y{sub 2}O{sub 3} powders are solid-state sintered at 1300-1450 deg. C for 1 h in hydrogen atmosphere, and followed by liquid phase sintering temperature at 1465-1485 deg. C for 0-60 min. The microstructure of ODS tungsten heavy alloys showed high relative density above 97%, with contiguous tungsten grains after primary solid-state sintering. The microstructure of solid-state sintered ODS tungsten heavy alloy was changed into spherical tungsten grains embedded in W-Ni-Fe matrix during secondary liquid phase sintering. The two-stage sintered ODS tungsten heavy alloy from mechanically alloyed powders showed finer microstructure and higher mechanical properties than conventional liquid phase sintered alloy. The mechanical properties of ODS tungsten heavy alloys are dependent on the microstructural parameters such as tungsten grain size, matrix volume fraction and tungsten/tungsten contiguity, which can be controlled through the two-stage sintering process.

Two-stage nonrecursive filter/decimator

International Nuclear Information System (INIS)

Yoder, J.R.; Richard, B.D.

1980-08-01

A two-stage digital filter/decimator has been designed and implemented to reduce the sampling rate associated with the long-term computer storage of certain digital waveforms. This report describes the design selection and implementation process and serves as documentation for the system actually installed. A filter design with finite-impulse response (nonrecursive) was chosen for implementation via direct convolution. A newly-developed system-test statistic validates the system under different computer-operating environments

THE MATHEMATICAL MODEL DEVELOPMENT OF THE ETHYLBENZENE DEHYDROGENATION PROCESS KINETICS IN A TWO-STAGE ADIABATIC CONTINUOUS REACTOR

Directory of Open Access Journals (Sweden)

V. K. Bityukov

2015-01-01

Full Text Available The article is devoted to the mathematical modeling of the kinetics of ethyl benzene dehydrogenation in a two-stage adiabatic reactor with a catalytic bed functioning on continuous technology. The analysis of chemical reactions taking place parallel to the main reaction of styrene formation has been carried out on the basis of which a number of assumptions were made proceeding from which a kinetic scheme describing the mechanism of the chemical reactions during the dehydrogenation process was developed. A mathematical model of the dehydrogenation process, describing the dynamics of chemical reactions taking place in each of the two stages of the reactor block at a constant temperature is developed. The estimation of the rate constants of direct and reverse reactions of each component, formation and exhaustion of the reacted mixture was made. The dynamics of the starting material concentration variations (ethyl benzene batch was obtained as well as styrene formation dynamics and all byproducts of dehydrogenation (benzene, toluene, ethylene, carbon, hydrogen, ect.. The calculated the variations of the component composition of the reaction mixture during its passage through the first and second stages of the reactor showed that the proposed mathematical description adequately reproduces the kinetics of the process under investigation. This demonstrates the advantage of the developed model, as well as loyalty to the values found for the rate constants of reactions, which enable the use of models for calculating the kinetics of ethyl benzene dehydrogenation under nonisothermal mode in order to determine the optimal temperature trajectory of the reactor operation. In the future, it will reduce energy and resource consumption, increase the volume of produced styrene and improve the economic indexes of the process.

Laser surface cleaning

International Nuclear Information System (INIS)

Freiwald, J.G.; Freiwald, D.A.

1994-01-01

The objective of this work is a laboratory demonstration that red-lead primer and two-part epoxy paints can be stripped from concrete and metal surfaces using surface cleaning systems based on pulsed-repetition CO 2 lasers. The three goals are to: (1) demonstrate coatings removal, including surface pore cleaning; (2) demonstrate that there is negligible release of ablated contaminants to the environment; and (3) demonstrate that the process will generate negligible amounts of additional waste compared to competing technologies. Phase 1 involved site visits to RMI and Fernald to assess the cleaning issues for buildings and parts. In addition, Phase 1 included detailed designs of a more powerful system for industrial cleaning rates, including laser, articulating optics, ablated-material capture suction nozzle attached to a horizontal raster scanner for floor cleaning, and filtration system. Some concept development is also being done for using robots, and for parts cleaning. In Phase 2 a transportable 6 kW system will be built and tested, with a horizontal surface scanner for cleaning paint from floors. The laboratory tests will again be instrumented. Some concept development will continue for using robots, and for parts cleaning. This report describes Phase 1 results

Neural mechanisms of human perceptual learning: electrophysiological evidence for a two-stage process.

Science.gov (United States)

Hamamé, Carlos M; Cosmelli, Diego; Henriquez, Rodrigo; Aboitiz, Francisco

2011-04-26

Humans and other animals change the way they perceive the world due to experience. This process has been labeled as perceptual learning, and implies that adult nervous systems can adaptively modify the way in which they process sensory stimulation. However, the mechanisms by which the brain modifies this capacity have not been sufficiently analyzed. We studied the neural mechanisms of human perceptual learning by combining electroencephalographic (EEG) recordings of brain activity and the assessment of psychophysical performance during training in a visual search task. All participants improved their perceptual performance as reflected by an increase in sensitivity (d') and a decrease in reaction time. The EEG signal was acquired throughout the entire experiment revealing amplitude increments, specific and unspecific to the trained stimulus, in event-related potential (ERP) components N2pc and P3 respectively. P3 unspecific modification can be related to context or task-based learning, while N2pc may be reflecting a more specific attentional-related boosting of target detection. Moreover, bell and U-shaped profiles of oscillatory brain activity in gamma (30-60 Hz) and alpha (8-14 Hz) frequency bands may suggest the existence of two phases for learning acquisition, which can be understood as distinctive optimization mechanisms in stimulus processing. We conclude that there are reorganizations in several neural processes that contribute differently to perceptual learning in a visual search task. We propose an integrative model of neural activity reorganization, whereby perceptual learning takes place as a two-stage phenomenon including perceptual, attentional and contextual processes.

Recovery of clean coal fines through a combination of gravity concentrator and flotation processes

Energy Technology Data Exchange (ETDEWEB)

Gupta, A.K.; Banerjee, P.K.; Dutta, A.; Mishra, A. [Tata Steel, Jamshedpur (India). Research & Development

2007-07-01

Flotation feed is a mixture of coarse and ultra-fine fractions. During conditioning of the flotation feed with collector and frother, the finer fraction consumes more reagents as compared to coarser particles. This is mainly due to more specific surface area of the ultra fine than the coarse fraction. This favors the adsorption of reagents toward ultra-finer fractions leads to less complete surface coverage of coarse particles and more entrainment of finer gangue particles. This results in the lower yield of coarse fractions from the flotation circuit and loss in selectivity. Hence, the major challenge is to improve the recovery of the coarser fraction and selectivity of ultra-fine fractions by improving flotation kinetics of all size fractions. This article deals with an approach to overcome the improper reagent adsorption by fine and coarse coal fractions in the flotation circuit through an innovative washing circuit containing gravity operation and flotation processes. Flotation performance between a new washing circuit having stub cyclone and flotation and normal single-stage reagent addition flotation process is compared in terms of selectivity, separation efficiency, rate constant, and size-wise recovery. The washing circuit having stub cyclone and flotation processes improves the fine clean coal yield by 10% and reduces the consumption of reagent compared to the normal single-stage reagent addition flotation process.

Treatment of corn ethanol distillery wastewater using two-stage anaerobic digestion.

Science.gov (United States)

Ráduly, B; Gyenge, L; Szilveszter, Sz; Kedves, A; Crognale, S

In this study the mesophilic two-stage anaerobic digestion (AD) of corn bioethanol distillery wastewater is investigated in laboratory-scale reactors. Two-stage AD technology separates the different sub-processes of the AD in two distinct reactors, enabling the use of optimal conditions for the different microbial consortia involved in the different process phases, and thus allowing for higher applicable organic loading rates (OLRs), shorter hydraulic retention times (HRTs) and better conversion rates of the organic matter, as well as higher methane content of the produced biogas. In our experiments the reactors have been operated in semi-continuous phase-separated mode. A specific methane production of 1,092 mL/(L·d) has been reached at an OLR of 6.5 g TCOD/(L·d) (TCOD: total chemical oxygen demand) and a total HRT of 21 days (5.7 days in the first-stage, and 15.3 days in the second-stage reactor). Nonetheless the methane concentration in the second-stage reactor was very high (78.9%); the two-stage AD outperformed the reference single-stage AD (conducted at the same reactor loading rate and retention time) by only a small margin in terms of volumetric methane production rate. This makes questionable whether the higher methane content of the biogas counterbalances the added complexity of the two-stage digestion.

Tests of an environmental and personnel safe cleaning process for Brookhaven National Laboratory accelerator and storage ring components

International Nuclear Information System (INIS)

Foerster, C.L.; Lanni, C.; Lee, R.; Mitchell, G.; Quade, W.

1997-01-01

A large measure of the successful operation of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL) for over a decade can be attributed to the cleaning of its ultrahigh vacuum (UHV) components during and after construction. A new UHV cleaning process, which has to be environmentally and personnel safe, is needed to replace the harsh, unfriendly process which is still in use. Dow Advanced Cleaning Systems was contracted to develop a replacement process without the use of harsh chemicals and which must clean vacuum surfaces as well as the existing process. Acceptance of the replacement process was primarily based on photon stimulated desorption (PSD) measurements of beam tube samples run on NSLS beam line U10B. One meter long beam tube samples were fabricated from aluminum, 304 stainless steel, and oxygen-free copper. Initially, coupon samples were cleaned and passed preliminary testing for the proposed process. Next, beam tube samples of each material were cleaned, and the PSD measured on beam line U10B using white light with a critical energy of 487 eV. Prior to cleaning, the samples were contaminated with a mixture of cutting oils, lubricants, vacuum oils, and vacuum grease. The contaminated samples were then baked. Samples of each material were also cleaned with the existing process after the same preparation. Beam tube samples were exposed to between 10 22 and 10 23 photons per meter for a PSD measurement. Desorption yields for H 2 , CO, CO 2 , CH 4 , and H 2 O are reported for both the existing cleaning and for the replacement cleaning process. Preliminary data, residual gas scans, and PSD results are given and discussed. The new process is also compared with new cleaning methods developed in other laboratories. After modification, the new UHV cleaning process was accepted by BNL

Determination of a cleaning and decontamination process using solvents

International Nuclear Information System (INIS)

Boutot, P.; Schipfer, P.

1967-03-01

This work has been carried out on samples of the white cotton serge material of which most of the working overalls of the Nuclear Research Centre are made. The aims are: - to determine,from the decontamination and cleaning points of view, the efficiency of various solvents (white-spirit, trichloroethylene, perchlorethylene and tri-chloro-trifluoroethane) and the role of additives likely to improve the treatment; - to control the textile from the wear and shrinkage points of view; - to try to develop a basic cleaning and decontamination process as a function of the possibilities of each solvent considered. (authors) [fr

Optics of two-stage photovoltaic concentrators with dielectric second stages

Science.gov (United States)

Ning, Xiaohui; O'Gallagher, Joseph; Winston, Roland

1987-04-01

Two-stage photovoltaic concentrators with Fresnel lenses as primaries and dielectric totally internally reflecting nonimaging concentrators as secondaries are discussed. The general design principles of such two-stage systems are given. Their optical properties are studied and analyzed in detail using computer ray trace procedures. It is found that the two-stage concentrator offers not only a higher concentration or increased acceptance angle, but also a more uniform flux distribution on the photovoltaic cell than the point focusing Fresnel lens alone. Experimental measurements with a two-stage prototype module are presented and compared to the analytical predictions.

Optics of two-stage photovoltaic concentrators with dielectric second stages.

Science.gov (United States)

Ning, X; O'Gallagher, J; Winston, R

1987-04-01

Two-stage photovoltaic concentrators with Fresnel lenses as primaries and dielectric totally internally reflecting nonimaging concentrators as secondaries are discussed. The general design principles of such two-stage systems are given. Their optical properties are studied and analyzed in detail using computer ray trace procedures. It is found that the two-stage concentrator offers not only a higher concentration or increased acceptance angle, but also a more uniform flux distribution on the photovoltaic cell than the point focusing Fresnel lens alone. Experimental measurements with a two-stage prototype module are presented and compared to the analytical predictions.

Effect of ammoniacal nitrogen on one-stage and two-stage anaerobic digestion of food waste

International Nuclear Information System (INIS)

Ariunbaatar, Javkhlan; Scotto Di Perta, Ester; Panico, Antonio; Frunzo, Luigi; Esposito, Giovanni; Lens, Piet N.L.; Pirozzi, Francesco

2015-01-01

Highlights: • Almost 100% of the biomethane potential of food waste was recovered during AD in a two-stage CSTR. • Recirculation of the liquid fraction of the digestate provided the necessary buffer in the AD reactors. • A higher OLR (0.9 gVS/L·d) led to higher accumulation of TAN, which caused more toxicity. • A two-stage reactor is more sensitive to elevated concentrations of ammonia. • The IC 50 of TAN for the AD of food waste amounts to 3.8 g/L. - Abstract: This research compares the operation of one-stage and two-stage anaerobic continuously stirred tank reactor (CSTR) systems fed semi-continuously with food waste. The main purpose was to investigate the effects of ammoniacal nitrogen on the anaerobic digestion process. The two-stage system gave more reliable operation compared to one-stage due to: (i) a better pH self-adjusting capacity; (ii) a higher resistance to organic loading shocks; and (iii) a higher conversion rate of organic substrate to biomethane. Also a small amount of biohydrogen was detected from the first stage of the two-stage reactor making this system attractive for biohythane production. As the digestate contains ammoniacal nitrogen, re-circulating it provided the necessary alkalinity in the systems, thus preventing an eventual failure by volatile fatty acids (VFA) accumulation. However, re-circulation also resulted in an ammonium accumulation, yielding a lower biomethane production. Based on the batch experimental results the 50% inhibitory concentration of total ammoniacal nitrogen on the methanogenic activities was calculated as 3.8 g/L, corresponding to 146 mg/L free ammonia for the inoculum used for this research. The two-stage system was affected by the inhibition more than the one-stage system, as it requires less alkalinity and the physically separated methanogens are more sensitive to inhibitory factors, such as ammonium and propionic acid

Solar Energy for a Solvent Recovery Stage in a Biodiesel Production Process

Directory of Open Access Journals (Sweden)

José A. León

2016-01-01

Full Text Available Recent research and development of clean energy have become essential due to the global climate change problem, which is caused largely by fossil fuels burning. Therefore, biodiesel, a renewable and ecofriendly biofuel with less environmental impact than diesel, continues expanding worldwide. The process for biodiesel production involves a significant energy demand, specifically in the methanol recovery stage through a flash separator and a distillation column. Traditionally, the energy required for this process is supplied by fossil fuels. It represents an opportunity for the application of renewable energy. Hence, the current study presents a system of thermal energy storage modeled in TRNSYS® and supported by simulations performed in ASPEN PLUS®. The aim of this research was to supply solar energy for a methanol recovery stage in a biodiesel production process. The results highlighted that it is feasible to meet 91% of the energy demand with an array of 9 parabolic trough collectors. The array obtained from the simulation was 3 in series and 3 in parallel, with a total area of 118.8 m2. It represents an energy saving of 70 MWh per year.

Single-stage-to-orbit versus two-stage-two-orbit: A cost perspective

Science.gov (United States)

Hamaker, Joseph W.

1996-03-01

This paper considers the possible life-cycle costs of single-stage-to-orbit (SSTO) and two-stage-to-orbit (TSTO) reusable launch vehicles (RLV's). The analysis parametrically addresses the issue such that the preferred economic choice comes down to the relative complexity of the TSTO compared to the SSTO. The analysis defines the boundary complexity conditions at which the two configurations have equal life-cycle costs, and finally, makes a case for the economic preference of SSTO over TSTO.

Experimental evaluation of desuperheating and oil cooling process through liquid injection in two-staged ammonia refrigeration systems with screw compressors

International Nuclear Information System (INIS)

Zlatanović, Ivan; Rudonja, Nedžad

2012-01-01

This paper examines the problem of achieving desuperheating through liquid injection in two-staged refrigeration systems based on screw compressors. The oil cooling process by refrigerant injection is also included. The basic thermodynamic principles of desuperheating and compressor cooling as well as short comparison with traditional method with a thermosyphon system have also been presented. Finally, the collected data referring to a big refrigeration plant are analyzed in the paper. Specific ammonia system concept applied in this refrigeration plant has demonstrated its advantages and disadvantages. - Highlights: ► An experiment was setup during a frozen food factory refrigeration system reconstruction and adaptation. ► Desuperheating and low-stage compressors oil cooling process were investigated. ► Efficiency of compression process and high-stage compressors functioning were examined. ► Evaporation temperature reduction has great influence on the need for injected liquid refrigerant. ► Several cases in which desuperheating and oil cooling process application are justified were determined.

Modelling of Two-Stage Methane Digestion With Pretreatment of Biomass

Science.gov (United States)

Dychko, A.; Remez, N.; Opolinskyi, I.; Kraychuk, S.; Ostapchuk, N.; Yevtieieva, L.

2018-04-01

Systems of anaerobic digestion should be used for processing of organic waste. Managing the process of anaerobic recycling of organic waste requires reliable predicting of biogas production. Development of mathematical model of process of organic waste digestion allows determining the rate of biogas output at the two-stage process of anaerobic digestion considering the first stage. Verification of Konto's model, based on the studied anaerobic processing of organic waste, is implemented. The dependencies of biogas output and its rate from time are set and may be used to predict the process of anaerobic processing of organic waste.

A two-stage predictive model to simultaneous control of trihalomethanes in water treatment plants and distribution systems: adaptability to treatment processes.

Science.gov (United States)

Domínguez-Tello, Antonio; Arias-Borrego, Ana; García-Barrera, Tamara; Gómez-Ariza, José Luis

2017-10-01

The trihalomethanes (TTHMs) and others disinfection by-products (DBPs) are formed in drinking water by the reaction of chlorine with organic precursors contained in the source water, in two consecutive and linked stages, that starts at the treatment plant and continues in second stage along the distribution system (DS) by reaction of residual chlorine with organic precursors not removed. Following this approach, this study aimed at developing a two-stage empirical model for predicting the formation of TTHMs in the water treatment plant and subsequently their evolution along the water distribution system (WDS). The aim of the two-stage model was to improve the predictive capability for a wide range of scenarios of water treatments and distribution systems. The two-stage model was developed using multiple regression analysis from a database (January 2007 to July 2012) using three different treatment processes (conventional and advanced) in the water supply system of Aljaraque area (southwest of Spain). Then, the new model was validated using a recent database from the same water supply system (January 2011 to May 2015). The validation results indicated no significant difference in the predictive and observed values of TTHM (R 2 0.874, analytical variance distribution systems studied, proving the adaptability of the new model to the boundary conditions. Finally the predictive capability of the new model was compared with 17 other models selected from the literature, showing satisfactory results prediction and excellent adaptability to treatment processes.

A two-stage heating scheme for heat assisted magnetic recording

Science.gov (United States)

Xiong, Shaomin; Kim, Jeongmin; Wang, Yuan; Zhang, Xiang; Bogy, David

2014-05-01

Heat Assisted Magnetic Recording (HAMR) has been proposed to extend the storage areal density beyond 1 Tb/in.2 for the next generation magnetic storage. A near field transducer (NFT) is widely used in HAMR systems to locally heat the magnetic disk during the writing process. However, much of the laser power is absorbed around the NFT, which causes overheating of the NFT and reduces its reliability. In this work, a two-stage heating scheme is proposed to reduce the thermal load by separating the NFT heating process into two individual heating stages from an optical waveguide and a NFT, respectively. As the first stage, the optical waveguide is placed in front of the NFT and delivers part of laser energy directly onto the disk surface to heat it up to a peak temperature somewhat lower than the Curie temperature of the magnetic material. Then, the NFT works as the second heating stage to heat a smaller area inside the waveguide heated area further to reach the Curie point. The energy applied to the NFT in the second heating stage is reduced compared with a typical single stage NFT heating system. With this reduced thermal load to the NFT by the two-stage heating scheme, the lifetime of the NFT can be extended orders longer under the cyclic load condition.

Two-stage Lagrangian modeling of ignition processes in ignition quality tester and constant volume combustion chambers

KAUST Repository

Alfazazi, Adamu

2016-08-10

The ignition characteristics of isooctane and n-heptane in an ignition quality tester (IQT) were simulated using a two-stage Lagrangian (TSL) model, which is a zero-dimensional (0-D) reactor network method. The TSL model was also used to simulate the ignition delay of n-dodecane and n-heptane in a constant volume combustion chamber (CVCC), which is archived in the engine combustion network (ECN) library (http://www.ca.sandia.gov/ecn). A detailed chemical kinetic model for gasoline surrogates from the Lawrence Livermore National Laboratory (LLNL) was utilized for the simulation of n-heptane and isooctane. Additional simulations were performed using an optimized gasoline surrogate mechanism from RWTH Aachen University. Validations of the simulated data were also performed with experimental results from an IQT at KAUST. For simulation of n-dodecane in the CVCC, two n-dodecane kinetic models from the literature were utilized. The primary aim of this study is to test the ability of TSL to replicate ignition timings in the IQT and the CVCC. The agreement between the model and the experiment is acceptable except for isooctane in the IQT and n-heptane and n-dodecane in the CVCC. The ability of the simulations to replicate observable trends in ignition delay times with regard to changes in ambient temperature and pressure allows the model to provide insights into the reactions contributing towards ignition. Thus, the TSL model was further employed to investigate the physical and chemical processes responsible for controlling the overall ignition under various conditions. The effects of exothermicity, ambient pressure, and ambient oxygen concentration on first stage ignition were also studied. Increasing ambient pressure and oxygen concentration was found to shorten the overall ignition delay time, but does not affect the timing of the first stage ignition. Additionally, the temperature at the end of the first stage ignition was found to increase at higher ambient pressure

Two-stage perceptual learning to break visual crowding.

Science.gov (United States)

Zhu, Ziyun; Fan, Zhenzhi; Fang, Fang

2016-01-01

When a target is presented with nearby flankers in the peripheral visual field, it becomes harder to identify, which is referred to as crowding. Crowding sets a fundamental limit of object recognition in peripheral vision, preventing us from fully appreciating cluttered visual scenes. We trained adult human subjects on a crowded orientation discrimination task and investigated whether crowding could be completely eliminated by training. We discovered a two-stage learning process with this training task. In the early stage, when the target and flankers were separated beyond a certain distance, subjects acquired a relatively general ability to break crowding, as evidenced by the fact that the breaking of crowding could transfer to another crowded orientation, even a crowded motion stimulus, although the transfer to the opposite visual hemi-field was weak. In the late stage, like many classical perceptual learning effects, subjects' performance gradually improved and showed specificity to the trained orientation. We also found that, when the target and flankers were spaced too finely, training could only reduce, rather than completely eliminate, the crowding effect. This two-stage learning process illustrates a learning strategy for our brain to deal with the notoriously difficult problem of identifying peripheral objects in clutter. The brain first learned to solve the "easy and general" part of the problem (i.e., improving the processing resolution and segmenting the target and flankers) and then tackle the "difficult and specific" part (i.e., refining the representation of the target).

The Design, Construction and Operation of a 75 kW Two-Stage Gasifier

DEFF Research Database (Denmark)

Henriksen, Ulrik Birk; Ahrenfeldt, Jesper; Jensen, Torben Kvist

2003-01-01

The Two-Stage Gasifier was operated for several weeks (465 hours) and of these 190 hours continuously. The gasifier is operated automatically unattended day and night, and only small adjustments of the feeding rate were necessary once or twice a day. The operation was successful, and the output...... as expected. The engine operated well on the produced gas, and no deposits were observed in the engine afterwards. The bag house filter was an excellent and well operating gas cleaning system. Small amounts of deposits consisting of salts and carbonates were observed in the hot gas heat exchangers. The top...

Development of ultra low dew-point clean air generator; Cho tei roten seijo kuki hassei sochi no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Nishimura, H.; Okamura, N. [Takasago thermal Engineering Co., Ltd., Kanagawa (Japan)

2000-05-10

To reduce the manufacturing cost of semiconductors, some systems have been proposed that use a cheap and high purity Clean Dry Air (CDA). CDA can reduce process step such as wafer cleaning, because CDA flow in stocker prevents the wafer surface from adsorbing of moisture and organic impurities. We have already optimized a two-stage rotary dehumidifier and have conducted a study of methods for cheaply manufacturing air that has a low dew-point of -70 degree C to -50 degree C. We have further developed the method in which a dry dehumidifier is used, and developed an ultra low dew-point air generator. The air generator is a three-stage rotary dehumidifier in which a further stage is added to the two-stage rotary dehumidifier. The main component of the rotors is metal silicate. The air generator can supply dry air with a dew-point of -110 degree C. or less, in which the concentration in all gaseous contaminants is far below 1 ppb. We made a trial calculation of the manufacturing cost, and an average cost of 0.25 yen/m{sup 3} was obtained. (author)

Two-Stage Power Factor Corrected Power Supplies: The Low Component-Stress Approach

DEFF Research Database (Denmark)

Petersen, Lars; Andersen, Michael Andreas E.

2002-01-01

The discussion concerning the use of single-stage contra two-stage PFC solutions has been going on for the last decade and it continues. The purpose of this paper is to direct the focus back on how the power is processed and not so much as to the number of stages or the amount of power processed...

Challenges with modifications of the McClean Lake mill to process midwest ore

International Nuclear Information System (INIS)

Nguyen, T.T.; Backham, L.

2010-01-01

Midwest is a unique uranium deposit with exceptionally high arsenic content. The ore body is located 17 km west of the McClean Lake operation. The McClean Lake mill will be modified to process Midwest ore and handle solid wastes from the Midwest water treatment plant. This paper describes the modifications required of the McClean Lake mill, process challenges associated with treatment of the arsenic, and the possibility of recovering nickel and cobalt as a by-product. It also reviews the complexity in the design of the Midwest water treatment facility which incorporates reverse osmosis technology with conventional physical-chemical water treatment. (author)

Application of rapid read-out cleaning indicators for improved process control in hospital sterile services departments.

Science.gov (United States)

Nugent, P G; Modi, T; McLeod, N; Bock, L J; Smith, C; Poolman, T M; Warburton, R; Meighan, P; Wells, P; Sutton, J M

2013-05-01

Heightened awareness of the importance of cleaning has led to an emphasis on automated systems for the decontamination of re-usable medical devices. The authors have previously described an enzymatic indicator system, based on thermostable adenylate kinases (tAK), for quantitative monitoring of automated cleaning processes within hospital sterile services departments (SSDs). To evaluate tAK indicators for routine process monitoring across a range of SSDs with different cleaning chemistries and different automated washer disinfectors (AWDs). tAK indicator devices and alternative industry test indicators were included in five independent cleaning cycles in each of eight different AWDs. Residual tAK post wash was determined by a coupled luciferase assay using a modified hygiene monitoring system. In all cases, with the exception of a single test, the alternative indicators showed that cleaning had been adequate. They were not able to discriminate between the performance of different processes. In contrast, the tAK indicators were able to resolve differences in the performance of processes across the different SSDs. Where the tAK indicators identified cleaning to the limits of detection of the assay, this demonstrated a log10 enzyme removal factor of >5.69. The results suggest that tAK indicators are suitable for providing improved process control for automated cleaning processes, being able to distinguish between wash performance in different hospital settings and between individual process runs. This technology is believed to be a useful addition to routine AWD performance qualification when used as a daily or weekly test. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Hybrid alkali-hydrodynamic disintegration of waste-activated sludge before two-stage anaerobic digestion process.

Science.gov (United States)

Grübel, Klaudiusz; Suschka, Jan

2015-05-01

The first step of anaerobic digestion, the hydrolysis, is regarded as the rate-limiting step in the degradation of complex organic compounds, such as waste-activated sludge (WAS). The aim of lab-scale experiments was to pre-hydrolyze the sludge by means of low intensive alkaline sludge conditioning before applying hydrodynamic disintegration, as the pre-treatment procedure. Application of both processes as a hybrid disintegration sludge technology resulted in a higher organic matter release (soluble chemical oxygen demand (SCOD)) to the liquid sludge phase compared with the effects of processes conducted separately. The total SCOD after alkalization at 9 pH (pH in the range of 8.96-9.10, SCOD = 600 mg O2/L) and after hydrodynamic (SCOD = 1450 mg O2/L) disintegration equaled to 2050 mg/L. However, due to the synergistic effect, the obtained SCOD value amounted to 2800 mg/L, which constitutes an additional chemical oxygen demand (COD) dissolution of about 35 %. Similarly, the synergistic effect after alkalization at 10 pH was also obtained. The applied hybrid pre-hydrolysis technology resulted in a disintegration degree of 28-35%. The experiments aimed at selection of the most appropriate procedures in terms of optimal sludge digestion results, including high organic matter degradation (removal) and high biogas production. The analyzed soft hybrid technology influenced the effectiveness of mesophilic/thermophilic anaerobic digestion in a positive way and ensured the sludge minimization. The adopted pre-treatment technology (alkalization + hydrodynamic cavitation) resulted in 22-27% higher biogas production and 13-28% higher biogas yield. After two stages of anaerobic digestion (mesophilic conditions (MAD) + thermophilic anaerobic digestion (TAD)), the highest total solids (TS) reduction amounted to 45.6% and was received for the following sample at 7 days MAD + 17 days TAD. About 7% higher TS reduction was noticed compared with the sample after 9

Hydrogen and methane production from condensed molasses fermentation soluble by a two-stage anaerobic process

Energy Technology Data Exchange (ETDEWEB)

Lin, Chiu-Yue; Liang, You-Chyuan; Lay, Chyi-How [Feng Chia Univ., Taichung, Taiwan (China). Dept. of Environmental Engineering and Science; Chen, Chin-Chao [Chungchou Institute of Technology, Taiwan (China). Environmental Resources Lab.; Chang, Feng-Yuan [Feng Chia Univ., Taichung, Taiwan (China). Research Center for Energy and Resources

2010-07-01

The treatment of condensed molasses fermentation soluble (CMS) is a troublesome problem for glutamate manufacturing factory. However, CMS contains high carbohydrate and nutrient contents and is an attractive and commercially potential feedstock for bioenergy production. The aim of this paper is to produce hydrogen and methane by two-stage anaerobic fermentation process. The fermentative hydrogen production from CMS was conducted in a continuously-stirred tank bioreactor (working volume 4 L) which was operated at a hydraulic retention time (HRT) of 8 h, organic loading rate (OLR) of 120 kg COD/m{sup 3}-d, temperature of 35 C, pH 5.5 and sewage sludge as seed. The anaerobic methane production was conducted in an up-flow bioreactor (working volume 11 L) which was operated at a HRT of 24 -60 hrs, OLR of 4.0-10 kg COD/m{sup 3}-d, temperature of 35 C, pH 7.0 with using anaerobic granule sludge from fructose manufacturing factory as the seed and the effluent from hydrogen production process as the substrate. These two reactors have been operated successfully for more than 400 days. The steady-state hydrogen content, hydrogen production rate and hydrogen production yield in the hydrogen fermentation system were 37%, 169 mmol-H{sub 2}/L-d and 93 mmol-H{sub 2}/g carbohydrate{sub removed}, respectively. In the methane fermentation system, the peak methane content and methane production rate were 66.5 and 86.8 mmol-CH{sub 4}/L-d with methane production yield of 189.3 mmol-CH{sub 4}/g COD{sub removed} at an OLR 10 kg/m{sup 3}-d. The energy production rate was used to elucidate the energy efficiency for this two-stage process. The total energy production rate of 133.3 kJ/L/d was obtained with 5.5 kJ/L/d from hydrogen fermentation and 127.8 kJ/L/d from methane fermentation. (orig.)

Effect of ammoniacal nitrogen on one-stage and two-stage anaerobic digestion of food waste

Energy Technology Data Exchange (ETDEWEB)

Ariunbaatar, Javkhlan, E-mail: jaka@unicas.it [Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Via Di Biasio 43, 03043 Cassino, FR (Italy); UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft (Netherlands); Scotto Di Perta, Ester [Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, Via Claudio 21, 80125 Naples (Italy); Panico, Antonio [Telematic University PEGASO, Piazza Trieste e Trento, 48, 80132 Naples (Italy); Frunzo, Luigi [Department of Mathematics and Applications Renato Caccioppoli, University of Naples Federico II, Via Claudio, 21, 80125 Naples (Italy); Esposito, Giovanni [Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Via Di Biasio 43, 03043 Cassino, FR (Italy); Lens, Piet N.L. [UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft (Netherlands); Pirozzi, Francesco [Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, Via Claudio 21, 80125 Naples (Italy)

2015-04-15

Highlights: • Almost 100% of the biomethane potential of food waste was recovered during AD in a two-stage CSTR. • Recirculation of the liquid fraction of the digestate provided the necessary buffer in the AD reactors. • A higher OLR (0.9 gVS/L·d) led to higher accumulation of TAN, which caused more toxicity. • A two-stage reactor is more sensitive to elevated concentrations of ammonia. • The IC{sub 50} of TAN for the AD of food waste amounts to 3.8 g/L. - Abstract: This research compares the operation of one-stage and two-stage anaerobic continuously stirred tank reactor (CSTR) systems fed semi-continuously with food waste. The main purpose was to investigate the effects of ammoniacal nitrogen on the anaerobic digestion process. The two-stage system gave more reliable operation compared to one-stage due to: (i) a better pH self-adjusting capacity; (ii) a higher resistance to organic loading shocks; and (iii) a higher conversion rate of organic substrate to biomethane. Also a small amount of biohydrogen was detected from the first stage of the two-stage reactor making this system attractive for biohythane production. As the digestate contains ammoniacal nitrogen, re-circulating it provided the necessary alkalinity in the systems, thus preventing an eventual failure by volatile fatty acids (VFA) accumulation. However, re-circulation also resulted in an ammonium accumulation, yielding a lower biomethane production. Based on the batch experimental results the 50% inhibitory concentration of total ammoniacal nitrogen on the methanogenic activities was calculated as 3.8 g/L, corresponding to 146 mg/L free ammonia for the inoculum used for this research. The two-stage system was affected by the inhibition more than the one-stage system, as it requires less alkalinity and the physically separated methanogens are more sensitive to inhibitory factors, such as ammonium and propionic acid.

Prioritizing substitution of organic solvents in industrial cleaning processes

DEFF Research Database (Denmark)

Rasmussen, Pia Brunn; Jacobsen, Thomas

1997-01-01

A method for prioritizing the substitution of volatile organic compounds (VOC) used in industrial cleaning processes is developed. The result is a matrix, which, if all information can be obtained, gives a comprehensive description of the effects, exposure and emission of VOC, as well as the pros...

Minimizing makespan in a two-stage flow shop with parallel batch-processing machines and re-entrant jobs

Science.gov (United States)

Huang, J. D.; Liu, J. J.; Chen, Q. X.; Mao, N.

2017-06-01

Against a background of heat-treatment operations in mould manufacturing, a two-stage flow-shop scheduling problem is described for minimizing makespan with parallel batch-processing machines and re-entrant jobs. The weights and release dates of jobs are non-identical, but job processing times are equal. A mixed-integer linear programming model is developed and tested with small-scale scenarios. Given that the problem is NP hard, three heuristic construction methods with polynomial complexity are proposed. The worst case of the new constructive heuristic is analysed in detail. A method for computing lower bounds is proposed to test heuristic performance. Heuristic efficiency is tested with sets of scenarios. Compared with the two improved heuristics, the performance of the new constructive heuristic is superior.

Comparative effectiveness of one-stage versus two-stage basilic vein transposition arteriovenous fistulas.

Science.gov (United States)

Ghaffarian, Amir A; Griffin, Claire L; Kraiss, Larry W; Sarfati, Mark R; Brooke, Benjamin S

2018-02-01

Basilic vein transposition (BVT) fistulas may be performed as either a one-stage or two-stage operation, although there is debate as to which technique is superior. This study was designed to evaluate the comparative clinical efficacy and cost-effectiveness of one-stage vs two-stage BVT. We identified all patients at a single large academic hospital who had undergone creation of either a one-stage or two-stage BVT between January 2007 and January 2015. Data evaluated included patient demographics, comorbidities, medication use, reasons for abandonment, and interventions performed to maintain patency. Costs were derived from the literature, and effectiveness was expressed in quality-adjusted life-years (QALYs). We analyzed primary and secondary functional patency outcomes as well as survival during follow-up between one-stage and two-stage BVT procedures using multivariate Cox proportional hazards models and Kaplan-Meier analysis with log-rank tests. The incremental cost-effectiveness ratio was used to determine cost savings. We identified 131 patients in whom 57 (44%) one-stage BVT and 74 (56%) two-stage BVT fistulas were created among 8 different vascular surgeons during the study period that each performed both procedures. There was no significant difference in the mean age, male gender, white race, diabetes, coronary disease, or medication profile among patients undergoing one- vs two-stage BVT. After fistula transposition, the median follow-up time was 8.3 months (interquartile range, 3-21 months). Primary patency rates of one-stage BVT were 56% at 12-month follow-up, whereas primary patency rates of two-stage BVT were 72% at 12-month follow-up. Patients undergoing two-stage BVT also had significantly higher rates of secondary functional patency at 12 months (57% for one-stage BVT vs 80% for two-stage BVT) and 24 months (44% for one-stage BVT vs 73% for two-stage BVT) of follow-up (P < .001 using log-rank test). However, there was no significant difference

Two stage fluid bed-plasma gasification process for solid waste valorisation: Technical review and preliminary thermodynamic modelling of sulphur emissions

International Nuclear Information System (INIS)

Morrin, Shane; Lettieri, Paola; Chapman, Chris; Mazzei, Luca

2012-01-01

Highlights: ► We investigate sulphur during MSW gasification within a fluid bed-plasma process. ► We review the literature on the feed, sulphur and process principles therein. ► The need for research in this area was identified. ► We perform thermodynamic modelling of the fluid bed stage. ► Initial findings indicate the prominence of solid phase sulphur. - Abstract: Gasification of solid waste for energy has significant potential given an abundant feed supply and strong policy drivers. Nonetheless, significant ambiguities in the knowledge base are apparent. Consequently this study investigates sulphur mechanisms within a novel two stage fluid bed-plasma gasification process. This paper includes a detailed review of gasification and plasma fundamentals in relation to the specific process, along with insight on MSW based feedstock properties and sulphur pollutant therein. As a first step to understanding sulphur partitioning and speciation within the process, thermodynamic modelling of the fluid bed stage has been performed. Preliminary findings, supported by plant experience, indicate the prominence of solid phase sulphur species (as opposed to H 2 S) – Na and K based species in particular. Work is underway to further investigate and validate this.

USING CERAMIC MEMBRANES TO RECYCLE TWO NONIONIC ALKALINE METAL-CLEANING SOLUTIONS

Science.gov (United States)

One ZrO2 ultrafilter (0.05 um pore size) and two a-Al2O3 microfilters (0.2 and 0.8 um) were used to remove one synthetic ester oil and two polyalphaolefin-based and two petroleum hydrocarbon-based oils and greases from two nonionic alkaline cleaning solutions (e.g., Turco 4215-NC...

Design considerations for single-stage and two-stage pneumatic pellet injectors

International Nuclear Information System (INIS)

Gouge, M.J.; Combs, S.K.; Fisher, P.W.; Milora, S.L.

1988-09-01

Performance of single-stage pneumatic pellet injectors is compared with several models for one-dimensional, compressible fluid flow. Agreement is quite good for models that reflect actual breech chamber geometry and incorporate nonideal effects such as gas friction. Several methods of improving the performance of single-stage pneumatic pellet injectors in the near term are outlined. The design and performance of two-stage pneumatic pellet injectors are discussed, and initial data from the two-stage pneumatic pellet injector test facility at Oak Ridge National Laboratory are presented. Finally, a concept for a repeating two-stage pneumatic pellet injector is described. 27 refs., 8 figs., 3 tabs

Hybrid biogas upgrading in a two-stage thermophilic reactor

DEFF Research Database (Denmark)

Corbellini, Viola; Kougias, Panagiotis; Treu, Laura

2018-01-01

The aim of this study is to propose a hybrid biogas upgrading configuration composed of two-stage thermophilic reactors. Hydrogen is directly injected in the first stage reactor. The output gas from the first reactor (in-situ biogas upgrade) is subsequently transferred to a second upflow reactor...... (ex-situ upgrade), in which enriched hydrogenotrophic culture is responsible for the hydrogenation of carbon dioxide to methane. The overall objective of the work was to perform an initial methane enrichment in the in-situ reactor, avoiding deterioration of the process due to elevated pH levels......, and subsequently, to complete the biogas upgrading process in the ex-situ chamber. The methane content in the first stage reactor reached on average 87% and the corresponding value in the second stage was 91%, with a maximum of 95%. A remarkable accumulation of volatile fatty acids was observed in the first...

Development of chemical cleaning formulation for service water system of FBTR

International Nuclear Information System (INIS)

Velmurugan, S.; Narasimhan, S.V.; Das, P.C.; Mathur, P.K.

1995-01-01

Service water system of Fast Breeder Test Reactor (FBTR) was found to be corroded and at few locations, the corrosion product oxides were choking the smaller diameter pipelines. An attempt was made to develop a chemical cleaning formulation to chemically remove the oxides using a surface conditioner and chelating agents. Of the several complexants tested, hydroxyethylethylene diamine tetraacetic acid (HEDTA) was found to be better than other complexants from the point of view of oxide dissolution efficiency, solubility etc. A two stage chemical cleaning process involving conditioning of the oxide layer with 0.1% tannic acid followed by exposure of the conditioned oxide layer with a formulation containing 1% HEDTA + 0.5% Sodium Gluconate +0.2% hexamine was recommended to remove the corrosion product oxide present in the service water system. (author). 4 refs., 2 tabs

Adaptive Urban Stormwater Management Using a Two-stage Stochastic Optimization Model

Science.gov (United States)

Hung, F.; Hobbs, B. F.; McGarity, A. E.

2014-12-01

In many older cities, stormwater results in combined sewer overflows (CSOs) and consequent water quality impairments. Because of the expense of traditional approaches for controlling CSOs, cities are considering the use of green infrastructure (GI) to reduce runoff and pollutants. Examples of GI include tree trenches, rain gardens, green roofs, and rain barrels. However, the cost and effectiveness of GI are uncertain, especially at the watershed scale. We present a two-stage stochastic extension of the Stormwater Investment Strategy Evaluation (StormWISE) model (A. McGarity, JWRPM, 2012, 111-24) to explicitly model and optimize these uncertainties in an adaptive management framework. A two-stage model represents the immediate commitment of resources ("here & now") followed by later investment and adaptation decisions ("wait & see"). A case study is presented for Philadelphia, which intends to extensively deploy GI over the next two decades (PWD, "Green City, Clean Water - Implementation and Adaptive Management Plan," 2011). After first-stage decisions are made, the model updates the stochastic objective and constraints (learning). We model two types of "learning" about GI cost and performance. One assumes that learning occurs over time, is automatic, and does not depend on what has been done in stage one (basic model). The other considers learning resulting from active experimentation and learning-by-doing (advanced model). Both require expert probability elicitations, and learning from research and monitoring is modelled by Bayesian updating (as in S. Jacobi et al., JWRPM, 2013, 534-43). The model allocates limited financial resources to GI investments over time to achieve multiple objectives with a given reliability. Objectives include minimizing construction and O&M costs; achieving nutrient, sediment, and runoff volume targets; and community concerns, such as aesthetics, CO2 emissions, heat islands, and recreational values. CVaR (Conditional Value at Risk) and

Experimental study on an innovative multifunction heat pipe type heat recovery two-stage sorption refrigeration system

International Nuclear Information System (INIS)

Li, T.X.; Wang, R.Z.; Wang, L.W.; Lu, Z.S.

2008-01-01

An innovative multifunction heat pipe type sorption refrigeration system is designed, in which a two-stage sorption thermodynamic cycle based on two heat recovery processes was employed to reduce the driving heat source temperature, and the composite sorbent of CaCl 2 and activated carbon was used to improve the mass and heat transfer performances. For this test unit, the heating, cooling and heat recovery processes between two reactive beds are performed by multifunction heat pipes. The aim of this paper is to investigate the cycled characteristics of two-stage sorption refrigeration system with heat recovery processes. The two sub-cycles of a two-stage cycle have different sorption platforms though the adsorption and desorption temperatures are equivalent. The experimental results showed that the pressure evolutions of two beds are nearly equivalent during the first stage, and desorption pressure during the second stage is large higher than that in the first stage while the desorption temperatures are same during the two operation stages. In comparison with conventional two-stage cycle, the two-stage cycle with heat recovery processes can reduce the heating load for desorber and cooling load for adsorber, the coefficient of performance (COP) has been improved more than 23% when both cycles have the same regeneration temperature of 103 deg. C and the cooling water temperature of 30 deg. C. The advanced two-stage cycle provides an effective method for application of sorption refrigeration technology under the condition of low-grade temperature heat source or utilization of renewable energy

Transport fuels from two-stage coal liquefaction

Energy Technology Data Exchange (ETDEWEB)

Benito, A.; Cebolla, V.; Fernandez, I.; Martinez, M.T.; Miranda, J.L.; Oelert, H.; Prado, J.G. (Instituto de Carboquimica CSIC, Zaragoza (Spain))

1994-03-01

Four Spanish lignites and their vitrinite concentrates were evaluated for coal liquefaction. Correlationships between the content of vitrinite and conversion in direct liquefaction were observed for the lignites but not for the vitrinite concentrates. The most reactive of the four coals was processed in two-stage liquefaction at a higher scale. First-stage coal liquefaction was carried out in a continuous unit at Clausthal University at a temperature of 400[degree]C at 20 MPa hydrogen pressure and with anthracene oil as a solvent. The coal conversion obtained was 75.41% being 3.79% gases, 2.58% primary condensate and 69.04% heavy liquids. A hydroprocessing unit was built at the Instituto de Carboquimica for the second-stage coal liquefaction. Whole and deasphalted liquids from the first-stage liquefaction were processed at 450[degree]C and 10 MPa hydrogen pressure, with two commercial catalysts: Harshaw HT-400E (Co-Mo/Al[sub 2]O[sub 3]) and HT-500E (Ni-Mo/Al[sub 2]O[sub 3]). The effects of liquid hourly space velocity (LHSV), temperature, gas/liquid ratio and catalyst on the heteroatom liquids, and levels of 5 ppm of nitrogen and 52 ppm of sulphur were reached at 450[degree]C, 10 MPa hydrogen pressure, 0.08 kg H[sub 2]/kg feedstock and with Harshaw HT-500E catalyst. The liquids obtained were hydroprocessed again at 420[degree]C, 10 MPa hydrogen pressure and 0.06 kg H[sub 2]/kg feedstock to hydrogenate the aromatic structures. In these conditions, the aromaticity was reduced considerably, and 39% of naphthas and 35% of kerosene fractions were obtained. 18 refs., 4 figs., 4 tabs.

Treatment of waste water from flue gas cleaning; Behandlung von Abwasser der Rauchgasreinigung

Energy Technology Data Exchange (ETDEWEB)

Ogiermann, Klaus; Meyerhoff, Thomas [Berkefeld - VWS Deutschland GmbH, Celle (Germany); Hagen, Klaus [Berkefeld - VWS Deutschland GmbH, Bayreuth (Germany); Basabe, Juan Luis [HPD Process Engineering S.A., Bilbao (Spain); Vendrup, Michael [Krueger A/S, Soeborg (Denmark)

2012-11-01

Strict limits must be adhered to for treating waste water incurred during flue gas desulphurisation (FGD). One and two-stage precipitation processes have proven themselves in FGD waste water treatment. Metals can be removed with the MetClean {sup registered} process. Another option is evaporation. Waste water ZLD systems (Zero Liquid Discharge) recover, via a falling film evaporator with subsequent crystallisation, more than 98 % of the water and produce, aside from the condensate, only solid material that can be disposed of in landfill. A further development, named ZLD CoLD trademark, significantly reduces the investment and operating costs of this solution. (orig.)

Effluent composition prediction of a two-stage anaerobic digestion process: machine learning and stoichiometry techniques.

Science.gov (United States)

Alejo, Luz; Atkinson, John; Guzmán-Fierro, Víctor; Roeckel, Marlene

2018-05-16

Computational self-adapting methods (Support Vector Machines, SVM) are compared with an analytical method in effluent composition prediction of a two-stage anaerobic digestion (AD) process. Experimental data for the AD of poultry manure were used. The analytical method considers the protein as the only source of ammonia production in AD after degradation. Total ammonia nitrogen (TAN), total solids (TS), chemical oxygen demand (COD), and total volatile solids (TVS) were measured in the influent and effluent of the process. The TAN concentration in the effluent was predicted, this being the most inhibiting and polluting compound in AD. Despite the limited data available, the SVM-based model outperformed the analytical method for the TAN prediction, achieving a relative average error of 15.2% against 43% for the analytical method. Moreover, SVM showed higher prediction accuracy in comparison with Artificial Neural Networks. This result reveals the future promise of SVM for prediction in non-linear and dynamic AD processes. Graphical abstract ᅟ.

Two-Stage Series-Resonant Inverter

Science.gov (United States)

Stuart, Thomas A.

1994-01-01

Two-stage inverter includes variable-frequency, voltage-regulating first stage and fixed-frequency second stage. Lightweight circuit provides regulated power and is invulnerable to output short circuits. Does not require large capacitor across ac bus, like parallel resonant designs. Particularly suitable for use in ac-power-distribution system of aircraft.

Precipitation modeling of inclusions at different stages of the steel making process

International Nuclear Information System (INIS)

Carreno, V.; Morales, R.D.; Romeero, A.; Hernandez, M.; Morales, R.D.

1998-01-01

Steel making processes are continuously improved in order to attend the increasing requirements of the cleanness of the liquid metal. At the refining stages, as deoxidation and desulphuration, the formation of inclusions of oxides and sulphides is promoted, which on the other hand, are the most frequent inclusions. In this work a mathematical simulator of the precipitation and chemical composition of non-metallic inclusions at different steps of the steel making process is presented. To this purpose, it is assumed that inclusions formed by reoxidation can be simulated by increasing arbitrarily the oxygen levels consumed by the residual elements (aluminium, calcium, etc) and starting the chemical reaction with less powerful deoxidants (silicium and manganese). Accordingly, different operative conditions can be simulated. Numerical predictions are compared with experimental results of industrial trials, as well as results included in the bibliography. (Author) 7 refs

Temporary stages and motivational variables: Two complementary perspectives in the help-seeking process for mental disorders.

Science.gov (United States)

Del Valle Del Valle, Gema; Carrió, Carmen; Belloch, Amparo

2017-10-09

Help-seeking for mental disorders is a complex process, which includes different temporary stages, and in which the motivational variables play an especially relevant role. However, there is a lack of instruments to evaluate in depth both the temporary and motivational variables involved in the help-seeking process. This study aims to analyse in detail these two sets of variables, using a specific instrument designed for the purpose, to gain a better understanding of the process of treatment seeking. A total of 152 patients seeking treatment in mental health outpatient clinics of the NHS were individually interviewed: 71 had Obsessive-Compulsive Disorder, 21 had Agoraphobia, 18 had Major Depressive Disorder), 20 had Anorexia Nervosa, and 22 had Cocaine Dependence. The patients completed a structured interview assessing the help-seeking process. Disorder severity and quality of life was also assessed. The patients with agoraphobia and with major depression took significantly less time in recognising their mental health symptoms. Similarly, patients with major depression were faster in seeking professional help. Motivational variables were grouped in 3 sets: motivators for seeking treatment, related to the negative impact of symptoms on mood and to loss of control over symptoms; motivators for delaying treatment, related to minimisation of the disorder; and stigma-associated variables. The results support the importance of considering the different motivational variables involved in the several stages of the help-seeking process. The interview designed to that end has shown its usefulness in this endeavour. Copyright © 2017 SEP y SEPB. Publicado por Elsevier España, S.L.U. All rights reserved.

Controlling the cost of clean air - A new clean coal technology

International Nuclear Information System (INIS)

Kindig, J.K.; Godfrey, R.L.

1991-01-01

This article presents the authors' alternative to expensive coal combustion products clean-up by cleaning the coal, removing the sulfur, before combustion. Topics discussed include sulfur in coal and the coal cleaning process, the nature of a new coal cleaning technology, the impact on Clean Air Act compliance, and the economics of the new technology

Automated cleaning of electronic components

International Nuclear Information System (INIS)

Drotning, W.; Meirans, L.; Wapman, W.; Hwang, Y.; Koenig, L.; Petterson, B.

1994-01-01

Environmental and operator safety concerns are leading to the elimination of trichloroethylene and chlorofluorocarbon solvents in cleaning processes that remove rosin flux, organic and inorganic contamination, and particulates from electronic components. Present processes depend heavily on these solvents for manual spray cleaning of small components and subassemblies. Use of alternative solvent systems can lead to longer processing times and reduced quality. Automated spray cleaning can improve the quality of the cleaning process, thus enabling the productive use of environmentally conscious materials, while minimizing personnel exposure to hazardous materials. We describe the development of a prototype robotic system for cleaning electronic components in a spray cleaning workcell. An important feature of the prototype system is the capability to generate the robot paths and motions automatically from the CAD models of the part to be cleaned, and to embed cleaning process knowledge into the automatically programmed operations

Ultrasonic cleaning of electrodes of wire chambers

International Nuclear Information System (INIS)

Krasnov, V.A.; Kurepin, A.B.; Razin, V.I.

1980-01-01

A technological process of cleaning electrodes and working volume surfaces of wire chambers from contaminations by the simultaneous mechanical action of the energy of ultrasonic oscillations and the chemical action of detergents is discussed. A device for cleaning wire electrodes of proportional chambers of 0.3x0.4 m is described. The device uses two ultrasonic generators with a total power of 0.5 kW. As a detergent use is made of a mixture of ethyl alcohol, gasoline and freon. In the process of cleaning production defects can be detected in the wire chambers which makes it possible to timely remove the defects. Measurements of the surface resistance of fiberglass laminate of printed drift chamber electrodes at a voltage of 2 kV showed that after completing the cleaning process the resistance increases 15-20%

Two-stage anaerobic digestion of cheese whey

Energy Technology Data Exchange (ETDEWEB)

Lo, K V; Liao, P H

1986-01-01

A two-stage digestion of cheese whey was studied using two anaerobic rotating biological contact reactors. The second-stage reactor receiving partially treated effluent from the first-stage reactor could be operated at a hydraulic retention time of one day. The results indicated that two-stage digestion is a feasible alternative for treating whey. 6 references.

Computational Modelling of Large Scale Phage Production Using a Two-Stage Batch Process

Directory of Open Access Journals (Sweden)

Konrad Krysiak-Baltyn

2018-04-01

Full Text Available Cost effective and scalable methods for phage production are required to meet an increasing demand for phage, as an alternative to antibiotics. Computational models can assist the optimization of such production processes. A model is developed here that can simulate the dynamics of phage population growth and production in a two-stage, self-cycling process. The model incorporates variable infection parameters as a function of bacterial growth rate and employs ordinary differential equations, allowing application to a setup with multiple reactors. The model provides simple cost estimates as a function of key operational parameters including substrate concentration, feed volume and cycling times. For the phage and bacteria pairing examined, costs and productivity varied by three orders of magnitude, with the lowest cost found to be most sensitive to the influent substrate concentration and low level setting in the first vessel. An example case study of phage production is also presented, showing how parameter values affect the production costs and estimating production times. The approach presented is flexible and can be used to optimize phage production at laboratory or factory scale by minimizing costs or maximizing productivity.

Treatment of process water containing heavy metals with a two-stage electrolysis procedure in a membrane electrolysis cell

Energy Technology Data Exchange (ETDEWEB)

Fischer, R.; Krebs, P. [Technische Universitaet Dresden, Institut fuer Siedlungs- und Industriewasserwirtschaft, Mommsenstrasse 13, 01062 Dresden (Germany); Seidel, H. [UFZ-Umweltforschungszentrum Leipzig-Halle GmbH, Department Bioremediation, Permoserstrasse 15, D-04318 Leipzig (Germany); Morgenstern, P. [UFZ-Umweltforschungszentrum Leipzig-Halle GmbH, Department Analytik, Permoserstrasse 15, D-04318 Leipzig (Germany); Foerster, H.J.; Thiele, W. [Eilenburger Elektrolyse- und Umwelttechnik GmbH, Ziegelstrasse 2, D-04838 Eilenburg (Germany)

2005-04-01

The capability of a two-stage electrochemical treatment for the regeneration of acidic heavy-metal containing process water was examined. The process water came from sediment bioleaching and was characterized by a wide spectrum of dissolved metals, a high sulfate content, and a pH of about 3. In the modular laboratory model cell used, the anode chamber and the cathode chamber were separated by a central chamber fitted with an ion exchanger membrane on either side. The experiments were carried out applying a platinum anode and a graphite cathode at a current density of 0.1 A/cm{sup 2}. The circulation flow of the process water in the batch process amounted to 35 L/h, the electrolysis duration was 5.5 h at maximum and the total electrolysis current was about 1 A. In the first stage, the acidic process water containing metals passed through the cathode chamber. In the second stage, the cathodically pretreated process water was electrolyzed anodically. In the cathode chamber the main load of dissolved Cu, Zn, Cr and Pb was eliminated. The sulfuric acid surplus of 3-4 g/L decreased to about 1 g/L, the pH rose from initially 3.0 to 4-5, but the desired pH of 9-10 was not achieved. Precipitation in the proximity to the cathode evidently takes place at a higher pH than farther away. The dominant process in the anode chamber was the precipitation of amorphous MnO{sub 2} owing to the oxidation of dissolved Mn(II). The further depletion of the remaining heavy metals in the cathodically pretreated process water by subsequent anodic treatment was nearly exhaustive, more than 99 % of Cd, Cr, Cu, Mn, Ni, Pb, and Zn were removed from the leachate. The high depletion of heavy metals might be due to both the sorption on MnO{sub 2} precipitates and/or basic ferrous sulfate formed anodically, and the migration of metal ions through the cation exchanger membrane via the middle chamber into the cathode chamber. In the anode chamber, the sulfuric acid content increased to 6-7 g/L and the

On the robustness of two-stage estimators

KAUST Repository

Zhelonkin, Mikhail

2012-04-01

The aim of this note is to provide a general framework for the analysis of the robustness properties of a broad class of two-stage models. We derive the influence function, the change-of-variance function, and the asymptotic variance of a general two-stage M-estimator, and provide their interpretations. We illustrate our results in the case of the two-stage maximum likelihood estimator and the two-stage least squares estimator. © 2011.

Hydrogen production from cellulose in a two-stage process combining fermentation and electrohydrogenesis

KAUST Repository

Lalaurette, Elodie

2009-08-01

A two-stage dark-fermentation and electrohydrogenesis process was used to convert the recalcitrant lignocellulosic materials into hydrogen gas at high yields and rates. Fermentation using Clostridium thermocellum produced 1.67 mol H2/mol-glucose at a rate of 0.25 L H2/L-d with a corn stover lignocellulose feed, and 1.64 mol H2/mol-glucose and 1.65 L H2/L-d with a cellobiose feed. The lignocelluose and cellobiose fermentation effluent consisted primarily of: acetic, lactic, succinic, and formic acids and ethanol. An additional 800 ± 290 mL H2/g-COD was produced from a synthetic effluent with a wastewater inoculum (fermentation effluent inoculum; FEI) by electrohydrogensis using microbial electrolysis cells (MECs). Hydrogen yields were increased to 980 ± 110 mL H2/g-COD with the synthetic effluent by combining in the inoculum samples from multiple microbial fuel cells (MFCs) each pre-acclimated to a single substrate (single substrate inocula; SSI). Hydrogen yields and production rates with SSI and the actual fermentation effluents were 980 ± 110 mL/g-COD and 1.11 ± 0.13 L/L-d (synthetic); 900 ± 140 mL/g-COD and 0.96 ± 0.16 L/L-d (cellobiose); and 750 ± 180 mL/g-COD and 1.00 ± 0.19 L/L-d (lignocellulose). A maximum hydrogen production rate of 1.11 ± 0.13 L H2/L reactor/d was produced with synthetic effluent. Energy efficiencies based on electricity needed for the MEC using SSI were 270 ± 20% for the synthetic effluent, 230 ± 50% for lignocellulose effluent and 220 ± 30% for the cellobiose effluent. COD removals were ∼90% for the synthetic effluents, and 70-85% based on VFA removal (65% COD removal) with the cellobiose and lignocellulose effluent. The overall hydrogen yield was 9.95 mol-H2/mol-glucose for the cellobiose. These results show that pre-acclimation of MFCs to single substrates improves performance with a complex mixture of substrates, and that high hydrogen yields and gas production rates can be achieved using a two-stage fermentation and MEC

Treatment of natural rubber processing wastewater using a combination system of a two-stage up-flow anaerobic sludge blanket and down-flow hanging sponge system.

Science.gov (United States)

Tanikawa, D; Syutsubo, K; Hatamoto, M; Fukuda, M; Takahashi, M; Choeisai, P K; Yamaguchi, T

2016-01-01

A pilot-scale experiment of natural rubber processing wastewater treatment was conducted using a combination system consisting of a two-stage up-flow anaerobic sludge blanket (UASB) and a down-flow hanging sponge (DHS) reactor for more than 10 months. The system achieved a chemical oxygen demand (COD) removal efficiency of 95.7% ± 1.3% at an organic loading rate of 0.8 kg COD/(m(3).d). Bacterial activity measurement of retained sludge from the UASB showed that sulfate-reducing bacteria (SRB), especially hydrogen-utilizing SRB, possessed high activity compared with methane-producing bacteria (MPB). Conversely, the acetate-utilizing activity of MPB was superior to SRB in the second stage of the reactor. The two-stage UASB-DHS system can reduce power consumption by 95% and excess sludge by 98%. In addition, it is possible to prevent emissions of greenhouse gases (GHG), such as methane, using this system. Furthermore, recovered methane from the two-stage UASB can completely cover the electricity needs for the operation of the two-stage UASB-DHS system, accounting for approximately 15% of the electricity used in the natural rubber manufacturing process.

Sensitivity Analysis in Two-Stage DEA

Directory of Open Access Journals (Sweden)

Athena Forghani

2015-07-01

Full Text Available Data envelopment analysis (DEA is a method for measuring the efficiency of peer decision making units (DMUs which uses a set of inputs to produce a set of outputs. In some cases, DMUs have a two-stage structure, in which the first stage utilizes inputs to produce outputs used as the inputs of the second stage to produce final outputs. One important issue in two-stage DEA is the sensitivity of the results of an analysis to perturbations in the data. The current paper looks into combined model for two-stage DEA and applies the sensitivity analysis to DMUs on the entire frontier. In fact, necessary and sufficient conditions for preserving a DMU's efficiency classiffication are developed when various data changes are applied to all DMUs.

Sensitivity Analysis in Two-Stage DEA

Directory of Open Access Journals (Sweden)

Athena Forghani

2015-12-01

Full Text Available Data envelopment analysis (DEA is a method for measuring the efficiency of peer decision making units (DMUs which uses a set of inputs to produce a set of outputs. In some cases, DMUs have a two-stage structure, in which the first stage utilizes inputs to produce outputs used as the inputs of the second stage to produce final outputs. One important issue in two-stage DEA is the sensitivity of the results of an analysis to perturbations in the data. The current paper looks into combined model for two-stage DEA and applies the sensitivity analysis to DMUs on the entire frontier. In fact, necessary and sufficient conditions for preserving a DMU's efficiency classiffication are developed when various data changes are applied to all DMUs.

Two stage-type railgun accelerator

International Nuclear Information System (INIS)

Ogino, Mutsuo; Azuma, Kingo.

1995-01-01

The present invention provides a two stage-type railgun accelerator capable of spiking a flying body (ice pellet) formed by solidifying a gaseous hydrogen isotope as a fuel to a thermonuclear reactor at a higher speed into a central portion of plasmas. Namely, the two stage-type railgun accelerator accelerates the flying body spiked from a initial stage accelerator to a portion between rails by Lorentz force generated when electric current is supplied to the two rails by way of a plasma armature. In this case, two sets of solenoids are disposed for compressing the plasma armature in the longitudinal direction of the rails. The first and the second sets of solenoid coils are previously supplied with electric current. After passing of the flying body, the armature formed into plasmas by a gas laser disposed at the back of the flying body is compressed in the longitudinal direction of the rails by a magnetic force of the first and the second sets of solenoid coils to increase the plasma density. A current density is also increased simultaneously. Then, the first solenoid coil current is turned OFF to accelerate the flying body in two stages by the compressed plasma armature. (I.S.)

[Cleaning and disinfection in nursing homes. Data on quality of structure, process and outcome in nursing homes in Frankfurt am Main, Germany, 2011].

Science.gov (United States)

Heudorf, U; Gasteyer, S; Samoiski, Y; Voigt, K

2012-08-01

Due to the Infectious Disease Prevention Act, public health services in Germany are obliged to check the infection prevention in hospitals and other medical facilities as well as in nursing homes. In Frankfurt/Main, Germany, standardized control visits have been performed for many years. In 2011 focus was laid on cleaning and disinfection of surfaces. All 41 nursing homes were checked according to a standardized checklist covering quality of structure (i.e. staffing, hygiene concept), quality of process (observation of the cleaning processes in the homes) and quality of output, which was monitored by checking the cleaning of fluorescent marks which had been applied some days before and should have been removed via cleaning in the following days before the final check. In more than two thirds of the homes, cleaning personnel were salaried, in one third external personnel were hired. Of the homes 85% provided service clothing and all of them offered protective clothing. All homes had established hygiene and cleaning concepts, however, in 15% of the homes concepts for the handling of Norovirus and in 30% concepts for the handling of Clostridium difficile were missing. Regarding process quality only half of the processes observed, i.e. cleaning of hand contact surfaces, such as handrails, washing areas and bins, were correct. Only 44% of the cleaning controls were correct with enormous differences between the homes (0-100%). The correlation between quality of process and quality of output was significant. There was good quality of structure in the homes but regarding quality of process and outcome there was great need for improvement. This was especially due to faults in communication and coordination between cleaning personnel and nursing personnel. Quality outcome was neither associated with the number of the places for residents nor with staffing. Thus, not only quality of structure but also quality of process and outcome should be checked by the public health

A two-stage biological gas to liquid transfer process to convert carbon dioxide into bioplastic

KAUST Repository

Al Rowaihi, Israa

2018-03-06

The fermentation of carbon dioxide (CO2) with hydrogen (H2) uses available low-cost gases to synthesis acetic acid. Here, we present a two-stage biological process that allows the gas to liquid transfer (Bio-GTL) of CO2 into the biopolymer polyhydroxybutyrate (PHB). Using the same medium in both stages, first, acetic acid is produced (3.2 g L−1) by Acetobacterium woodii from 5.2 L gas-mixture of CO2:H2 (15:85 v/v) under elevated pressure (≥2.0 bar) to increase H2-solubility in water. Second, acetic acid is converted to PHB (3 g L−1 acetate into 0.5 g L−1 PHB) by Ralstonia eutropha H16. The efficiencies and space-time yields were evaluated, and our data show the conversion of CO2 into PHB with a 33.3% microbial cell content (percentage of the ratio of PHB concentration to cell concentration) after 217 h. Collectively, our results provide a resourceful platform for future optimization and commercialization of a Bio-GTL for PHB production.

Plasma cleaning for waste minimization

Energy Technology Data Exchange (ETDEWEB)

Ward, P.P.

1993-07-01

Although plasma cleaning is a recognized substitute for solvent cleaning in removing organic contaminants, some universal problems in plasma cleaning processes prevent wider use of plasma techniques. Lack of understanding of the fundamental mechanisms of the process, unreliable endpoint detection techniques, and slow process times make plasma cleaning processes less than desirable. Our approach to address these plasma cleaning problems is described. A comparison of plasma cleaning rates of oxygen and oxygen/sulfur hexafluoride gases shows that fluorine-containing plasmas can enhance etch rates by 400% over oxygen alone. A discussion of various endpoint indication techniques is discussed and compared for application suitability. Work toward a plasma cleaning database is discussed. In addition to the global problems of plasma cleaning, an experiment where the specific mixed-waste problem of removal of machine oils from radioactive scrap metal is discussed.

Ecological effectiveness of oil spill countermeasures: how clean is clean?

International Nuclear Information System (INIS)

Baker, J.M.

1999-01-01

This paper with 94 references examines background levels of hydrocarbons and the difficulty of defining clean. Processes and timescales for natural cleaning, and factors affecting natural cleaning timescales are considered. Ecological advantages and disadvantages of clean-up methods are highlighted, and five case histories of oil spills are summarised. The relationships between ecological and socio-economic considerations, and the need for a net environmental benefit analysis which takes into account the advantages and disadvantages of clean-up responses and natural clean-up are discussed. A decision tree for evaluating the requirement for shore clean-up is illustrated. (UK)

Effectiveness of HVAC duct cleaning procedures in improving indoor air quality.

Science.gov (United States)

Ahmad, I; Tansel, B; Mitrani, J D

2001-12-01

Indoor air quality has become one of the most serious environmental concerns as an average person spends about 22 hr indoors on a daily basis. The study reported in this article, was conducted to determine the effectiveness of three commercial HVAC (Heating Ventilation Air Conditioning) duct cleaning processes in reducing the level of airborne particulate matter and viable bioaerosols. The three HVAC sanitation processes were: (1) Contact method (use of conventional vacuum cleaning of interior duct surfaces); (2) Air sweep method (use of compressed air to dislodging dirt and debris); (3) Rotary brush method (insertion of a rotary brush into the ductwork to agitate and dislodge the debris). Effectiveness of these sanitation processes was evaluated in terms of airborne particulate and viable bioaerosol concentrations in residential homes. Eight identical homes were selected in the same neighborhood. Two homes were cleaned using each procedure and two were used as controls. It was found that both particle count readings and bioaerosol concentrations were higher when cleaning was being performed than before or after cleaning, which suggests that dirt, debris and other pollutants may become airborne as a result of disturbances caused by the cleaning processes. Particle count readings at 0.3 micron size were found to have increased due to cigarette smoking. Particle counts at 1.0 micron size were reduced due to HVAC duct cleaning. Post-level bioaerosol concentrations, taken two days after cleaning, were found to be lower than the pre-level concentrations suggesting that the cleaning procedures were effective to some extent. Homes cleaned with the Air Sweep procedure showed the highest degree of reduction in bioaerosol concentration among the three procedures investigated.

NICE3 SO3 Cleaning Process in Semiconductor Manufacturing

International Nuclear Information System (INIS)

Blazek, Steve

1999-01-01

This fact sheet explains how Anon, Inc., has developed a novel method of removing photoresist--a light-sensitive material used to produce semiconductor wafers for computers--from the computer manufacturing process at reduced cost and greater efficiency. The new technology is technically superior to existing semiconductor cleaning methods and results in reduced use of hazardous chemicals

Plasma Cleaning

Science.gov (United States)

Hintze, Paul E.

2016-01-01

NASA's Kennedy Space Center has developed two solvent-free precision cleaning techniques: plasma cleaning and supercritical carbon dioxide (SCCO2), that has equal performance, cost parity, and no environmental liability, as compared to existing solvent cleaning methods.

Device for two-stage cementing of casing

Energy Technology Data Exchange (ETDEWEB)

Kudimov, D A; Goncharevskiy, Ye N; Luneva, L G; Shchelochkov, S N; Shil' nikova, L N; Tereshchenko, V G; Vasiliev, V A; Volkova, V V; Zhdokov, K I

1981-01-01

A device is claimed for two-stage cementing of casing. It consists of a body with lateral plugging vents, upper and lower movable sleeves, a check valve with axial channels that's situated in the lower sleeve, and a displacement limiting device for the lower sleeve. To improve the cementing process of the casing by preventing overflow of cementing fluids from the annular space into the first stage casing, the limiter is equipped with a spring rod that is capable of covering the axial channels of the check valve while it's in an operating mode. In addition, the rod in the upper part is equipped with a reinforced area under the axial channels of the check valve.

Development of a two-stage inspection process for the assessment of deteriorating infrastructure

International Nuclear Information System (INIS)

Sheils, Emma; O'Connor, Alan; Breysse, Denys; Schoefs, Franck; Yotte, Sylvie

2010-01-01

Inspection-based maintenance strategies can provide an efficient tool for the management of ageing infrastructure subjected to deterioration. Many of these methods rely on quantitative data from inspections, rather than qualitative and subjective data. The focus of this paper is on the development of an inspection-based decision scheme, incorporating analysis on the effect of the cost and quality of NDT tools to assess the condition of infrastructure elements/networks during their lifetime. For the first time the two aspects of an inspection are considered, i.e. detection and sizing. Since each stage of an inspection is carried out for a distinct purpose, different parameters are used to represent each procedure and both have been incorporated into a maintenance management model. The separation of these procedures allows the interaction between the two inspection techniques to be studied. The inspection for detection process acts as a screening exercise to determine which defects require further inspection for sizing. A decision tool is developed that allows the owner/manager of the infrastructural element/network to choose the most cost-efficient maintenance management plan based on his/her specific requirements.

Two-stage implant systems.

Science.gov (United States)

Fritz, M E

1999-06-01

Since the advent of osseointegration approximately 20 years ago, there has been a great deal of scientific data developed on two-stage integrated implant systems. Although these implants were originally designed primarily for fixed prostheses in the mandibular arch, they have been used in partially dentate patients, in patients needing overdentures, and in single-tooth restorations. In addition, this implant system has been placed in extraction sites, in bone-grafted areas, and in maxillary sinus elevations. Often, the documentation of these procedures has lagged. In addition, most of the reports use survival criteria to describe results, often providing overly optimistic data. It can be said that the literature describes a true adhesion of the epithelium to the implant similar to adhesion to teeth, that two-stage implants appear to have direct contact somewhere between 50% and 70% of the implant surface, that the microbial flora of the two-stage implant system closely resembles that of the natural tooth, and that the microbiology of periodontitis appears to be closely related to peri-implantitis. In evaluations of the data from implant placement in all of the above-noted situations by means of meta-analysis, it appears that there is a strong case that two-stage dental implants are successful, usually showing a confidence interval of over 90%. It also appears that the mandibular implants are more successful than maxillary implants. Studies also show that overdenture therapy is valid, and that single-tooth implants and implants placed in partially dentate mouths have a success rate that is quite good, although not quite as high as in the fully edentulous dentition. It would also appear that the potential causes of failure in the two-stage dental implant systems are peri-implantitis, placement of implants in poor-quality bone, and improper loading of implants. There are now data addressing modifications of the implant surface to alter the percentage of

Two-stage revision of septic knee prosthesis with articulating knee spacers yields better infection eradication rate than one-stage or two-stage revision with static spacers.

Science.gov (United States)

Romanò, C L; Gala, L; Logoluso, N; Romanò, D; Drago, L

2012-12-01

The best method for treating chronic periprosthetic knee infection remains controversial. Randomized, comparative studies on treatment modalities are lacking. This systematic review of the literature compares the infection eradication rate after two-stage versus one-stage revision and static versus articulating spacers in two-stage procedures. We reviewed full-text papers and those with an abstract in English published from 1966 through 2011 that reported the success rate of infection eradication after one-stage or two-stage revision with two different types of spacers. In all, 6 original articles reporting the results after one-stage knee exchange arthoplasty (n = 204) and 38 papers reporting on two-stage revision (n = 1,421) were reviewed. The average success rate in the eradication of infection was 89.8% after a two-stage revision and 81.9% after a one-stage procedure at a mean follow-up of 44.7 and 40.7 months, respectively. The average infection eradication rate after a two-stage procedure was slightly, although significantly, higher when an articulating spacer rather than a static spacer was used (91.2 versus 87%). The methodological limitations of this study and the heterogeneous material in the studies reviewed notwithstanding, this systematic review shows that, on average, a two-stage procedure is associated with a higher rate of eradication of infection than one-stage revision for septic knee prosthesis and that articulating spacers are associated with a lower recurrence of infection than static spacers at a comparable mean duration of follow-up. IV.

Carbon dioxide cleaning pilot project

International Nuclear Information System (INIS)

Knight, L.; Blackman, T.E.

1994-01-01

In 1989, radioactive-contaminated metal at the Rocky Flats Plant (RFP) was cleaned using a solvent paint stripper (Methylene chloride). One-third of the radioactive material was able to be recycled; two-thirds went to the scrap pile as low-level mixed waste. In addition, waste solvent solutions also required disposal. Not only was this an inefficient process, it was later prohibited by the Resource Conservation and Recovery Act (RCRA), 40 CFR 268. A better way of doing business was needed. In the search for a solution to this situation, it was decided to study the advantages of using a new technology - pelletized carbon dioxide cleaning. A proof of principle demonstration occurred in December 1990 to test whether such a system could clean radioactive-contaminated metal. The proof of principle demonstration was expanded in June 1992 with a pilot project. The purpose of the pilot project was three fold: (1) to clean metal so that it can satisfy free release criteria for residual radioactive contamination at the Rocky Flats Plant (RFP); (2) to compare two different carbon dioxide cleaning systems; and (3) to determine the cost-effectiveness of decontamination process in a production situation and compare the cost of shipping the metal off site for waste disposal. The pilot project was completed in August 1993. The results of the pilot project were: (1) 90% of those items which were decontaminated, successfully met the free release criteria , (2) the Alpheus Model 250 was selected to be used on plantsite and (3) the break even cost of decontaminating the metal vs shipping the contaminated material offsite for disposal was a cleaning rate of 90 pounds per hour, which was easily achieved

Two-stage agglomeration of fine-grained herbal nettle waste

Science.gov (United States)

Obidziński, Sławomir; Joka, Magdalena; Fijoł, Olga

2017-10-01

This paper compares the densification work necessary for the pressure agglomeration of fine-grained dusty nettle waste, with the densification work involved in two-stage agglomeration of the same material. In the first stage, the material was pre-densified through coating with a binder material in the form of a 5% potato starch solution, and then subjected to pressure agglomeration. A number of tests were conducted to determine the effect of the moisture content in the nettle waste (15, 18 and 21%), as well as the process temperature (50, 70, 90°C) on the values of densification work and the density of the obtained pellets. For pre-densified pellets from a mixture of nettle waste and a starch solution, the conducted tests determined the effect of pellet particle size (1, 2, and 3 mm) and the process temperature (50, 70, 90°C) on the same values. On the basis of the tests, we concluded that the introduction of a binder material and the use of two-stage agglomeration in nettle waste densification resulted in increased densification work (as compared to the densification of nettle waste alone) and increased pellet density.

Nanotechnology Role for the Production of Clean Fuel E-85 and Petrochemical Raw Materials

Directory of Open Access Journals (Sweden)

Iskander K. Basily

2012-01-01

Full Text Available There have been a number of substantive technical changes that can be described as revolutionary process and evolutionary process. One of these approaches is the use of nanotechnology in the two-stage pyrolysis of petroleum residues of the heavy distillates separated from the Arabian crude oil. Two-stage catalytic pyrolysis technique proved to be an excellent method for the production of unsaturated hydrocarbons (which easily can be converted to alcohol, by addition of H2O, for the production of E-85, i.e., clean fuel regardless the type of feed stocks used. Basically, the catalysts are arranged into three large groups; amorphous and crystalline alumino-silicates, alkaline or alkaline earth alumino compounds, and different metal oxides on different catalyst carriers such as Zeolites. The high yield of ethylene (30–40% brought by different catalysts at temperatures of 700–750°C appear to justify the intensive research work in this field.

Modal intersection types, two-level languages, and staged synthesis

DEFF Research Database (Denmark)

Henglein, Fritz; Rehof, Jakob

2016-01-01

-linguistic framework for staged program synthesis, where metaprograms are automatically synthesized which, when executed, generate code in a target language. We survey the basic theory of staged synthesis and illustrate by example how a two-level language theory specialized from λ∩ ⎕ can be used to understand......A typed λ-calculus, λ∩ ⎕, is introduced, combining intersection types and modal types. We develop the metatheory of λ∩ ⎕, with particular emphasis on the theory of subtyping and distributivity of the modal and intersection type operators. We describe how a stratification of λ∩ ⎕ leads to a multi...... the process of staged synthesis....

Processes of elimination of activated corrosion products. Chemical decontamination - fuel cleaning

International Nuclear Information System (INIS)

Viala, C.; Brun, C.; Neuhaus, R.; Richier, S.; Bachet, M.

2007-01-01

The abatement of the individual and collective dose of a PWR imposes to control the source term through different processes implemented during the plant exploitation. When the limits of these different optimization processes are reached, the abatement of dose rates requires the implementation of curative processes. The objective is thus to eliminate the contaminated oxides and deposits present on surfaces free of radiation flux, and eventually on surfaces under radiation flux and on the fuel itself. The chemical decontamination of equipments and systems is the main and universal remedy implemented at different levels. On the other hand, the ultrasonic cleaning of fuel assemblies is a promising process. This paper aims at illustrating these different techniques using concrete examples of application in France and abroad (decontamination during steam generator replacement, decontamination of primary pump scroll in hot workshop, decontamination of loop sections, ultrasonic cleaning of fuel). The description of these different operations stresses on their efficiency in terms of dosimetric gain, duration of implementation, generation of wastes, and recontamination following their implementation. (J.S.)

Comparison of high‐intensity sound and mechanical vibration for cleaning porous titanium cylinders fabricated using selective laser melting

Science.gov (United States)

Seiffert, Gary; Sutcliffe, Chris

2015-01-01

Abstract Orthopedic components, such as the acetabular cup in total hip joint replacement, can be fabricated using porous metals, such as titanium, and a number of processes, such as selective laser melting. The issue of how to effectively remove loose powder from the pores (residual powder) of such components has not been addressed in the literature. In this work, we investigated the feasibility of two processes, acoustic cleaning using high‐intensity sound inside acoustic horns and mechanical vibration, to remove residual titanium powder from selective laser melting‐fabricated cylinders. With acoustic cleaning, the amount of residual powder removed was not influenced by either the fundamental frequency of the horn used (75 vs. 230 Hz) or, for a given horn, the number of soundings (between 1 and 20). With mechanical vibration, the amount of residual powder removed was not influenced by the application time (10 vs. 20 s). Acoustic cleaning was found to be more reliable and effective in removal of residual powder than cleaning with mechanical vibration. It is concluded that acoustic cleaning using high‐intensity sound has significant potential for use in the final preparation stages of porous metal orthopedic components. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 117–123, 2017. PMID:26426906

Biotransformation of Domestic Wastewater Treatment Plant Sludge by Two-Stage Integrated Processes -Lsb & Ssb

Directory of Open Access Journals (Sweden)

Md. Zahangir Alam, A. H. Molla and A. Fakhru’l-Razi

2012-10-01

Full Text Available The study of biotransformation of domestic wastewater treatment plant (DWTP sludge was conducted in laboratory-scale by two-stage integrated process i.e. liquid state bioconversion (LSB and solid state bioconversion (SSB processes. The liquid wastewater sludge [4% w/w of total suspended solids (TSS] was treated by mixed filamentous fungi Penicillium corylophilum and Aspergillus niger, isolated, screened and mixed cultured in terms of their higher biodegradation potential to wastewater sludge. The biosolids was increased to about 10% w/w. Conversely, the soluble [i.e. Total dissolve solid (TDS] and insoluble substances (TSS in treated supernatant were decreased effectively in the LSB process. In the developed LSB process, 93.8 g kg-1of biosolids were enriched with fungal biomass protein and nutrients (NPK, and 98.8% of TSS, 98.2% of TDS, 97.3% of turbidity, 80.2% of soluble protein, 98.8% of reducing sugar and 92.7% of chemical oxygen demand (COD in treated sludge supernatant were removed after 8 days of treatment. Specific resistance to filtration (1.39x1012 m/kg was decreased tremendously by the microbial treatment of DWTP sludge after 6 days of fermentation. The treated biosolids in DWTP sludge was considered as pretreated resource materials for composting and converted into compost by SSB process. The SSB process was evaluated for composting by monitoring the microbial growth and its subsequent roles in biodegradation in composting bin (CB. The process was conducted using two mixed fungal cultures, Trichoderma harzianum with Phanerochaete chrysosporium 2094 and (T/P and T. harzianum and Mucor hiemalis (T/M; and two bulking materials, sawdust (SD and rice straw (RS. The most encouraging results of microbial growth and subsequent solid state bioconversion were exhibited in the RS than the SD. Significant decrease of the C/N ratio and germination index (GI were attained as well as the higher value of glucosamine was exhibited in compost; which

How to Address the Data Quality Issues in Regression Models: A Guided Process for Data Cleaning

Directory of Open Access Journals (Sweden)

David Camilo Corrales

2018-04-01

Full Text Available Today, data availability has gone from scarce to superabundant. Technologies like IoT, trends in social media and the capabilities of smart-phones are producing and digitizing lots of data that was previously unavailable. This massive increase of data creates opportunities to gain new business models, but also demands new techniques and methods of data quality in knowledge discovery, especially when the data comes from different sources (e.g., sensors, social networks, cameras, etc.. The data quality process of the data set proposes conclusions about the information they contain. This is increasingly done with the aid of data cleaning approaches. Therefore, guaranteeing a high data quality is considered as the primary goal of the data scientist. In this paper, we propose a process for data cleaning in regression models (DC-RM. The proposed data cleaning process is evaluated through a real datasets coming from the UCI Repository of Machine Learning Databases. With the aim of assessing the data cleaning process, the dataset that is cleaned by DC-RM was used to train the same regression models proposed by the authors of UCI datasets. The results achieved by the trained models with the dataset produced by DC-RM are better than or equal to that presented by the datasets’ authors.

Extending CO2 cryogenic aerosol cleaning for advanced optical and EUV mask cleaning

Science.gov (United States)

Varghese, Ivin; Bowers, Charles W.; Balooch, Mehdi

2011-11-01

Cryogenic CO2 aerosol cleaning being a dry, chemically-inert and residue-free process is used in the production of optical lithography masks. It is an attractive cleaning option for the mask industry to achieve the requirement for removal of all printable soft defects and repair debris down to the 50nm printability specification. In the technique, CO2 clusters are formed by sudden expansion of liquid from high to almost atmospheric pressure through an optimally designed nozzle orifice. They are then directed on to the soft defects or debris for momentum transfer and subsequent damage free removal from the mask substrate. Unlike aggressive acid based wet cleaning, there is no degradation of the mask after processing with CO2, i.e., no critical dimension (CD) change, no transmission/phase losses, or chemical residue that leads to haze formation. Therefore no restriction on number of cleaning cycles is required to be imposed, unlike other cleaning methods. CO2 aerosol cleaning has been implemented for several years as full mask final clean in production environments at several state of the art mask shops. Over the last two years our group reported successful removal of all soft defects without damage to the fragile SRAF features, zero adders (from the cleaning and handling mechanisms) down to a 50nm printability specification. In addition, CO2 aerosol cleaning is being utilized to remove debris from Post-RAVE repair of hard defects in order to achieve the goal of no printable defects. It is expected that CO2 aerosol cleaning can be extended to extreme ultraviolet (EUV) masks. In this paper, we report advances being made in nozzle design qualification for optimum snow properties (size, velocity and flux) using Phase Doppler Anemometry (PDA) technique. In addition the two new areas of focus for CO2 aerosol cleaning i.e. pellicle glue residue removal on optical masks, and ruthenium (Ru) film on EUV masks are presented. Usually, the residue left over after the pellicle

Self Cleaning HEPA Filtration without Interrupting Process Flow

International Nuclear Information System (INIS)

Wylde, M.

2009-01-01

The strategy of protecting the traditional glass fibre HEPA filtration train from it's blinding contamination and the recovery of dust by the means of self cleaning, pre-filtration is a proven means in the reduction of ultimate disposal volumes and has been used within the Fuel Production Industry. However, there is an increasing demand in nuclear applications requiring elevated operating temperatures, fire resistance, moisture resistance and chemical composition that the existing glass fibre HEPA filtration cannot accommodate, which can be remedied by the use of a metallic HEPA filter media. Previous research (Bergman et al 1997, Moore et al 1992) suggests that the then costs to the DOE, based on a five year life cycle, was $29.5 million for the installation, testing, removal and disposal of glass fibre HEPA filtration trains. Within these costs, $300 was the value given to the filter and $4,450 was given to the peripheral activity. Development of a low cost, cleanable, metallic, direct replacement of the traditional filter train will the clear solution. The Bergman et al work has suggested that a 1000 ft 3 /min, cleanable, stainless HEPA could be commercially available for $5,000 each, whereas the industry has determined that the truer cost of such an item in isolation would be closer to $15,000. This results in a conflict within the requirement between 'low cost' and 'stainless HEPA'. By proposing a system that combines metallic HEPA filtration with the ability to self clean without interrupting the process flow, the need for a tradition HEPA filtration train will be eliminated and this dramatically reduces the resources required for cleaning or disposal, thus presenting a route to reducing ultimate costs. The paper will examine the performance characteristics, filtration efficiency, flow verses differential pressure and cleanability of a self cleaning HEPA grade sintered metal filter element, together with data to prove the contention. (authors)

Cleaning conveyor belts in the chicken-cutting area of a poultry processing plant with 45°c water.

Science.gov (United States)

Soares, V M; Pereira, J G; Zanette, C M; Nero, L A; Pinto, J P A N; Barcellos, V C; Bersot, L S

2014-03-01

Conveyor belts are widely used in food handling areas, especially in poultry processing plants. Because they are in direct contact with food and it is a requirement of the Brazilian health authority, conveyor belts are required to be continuously cleaned with hot water under pressure. The use of water in this procedure has been questioned based on the hypothesis that water may further disseminate microorganisms but not effectively reduce the organic material on the surface. Moreover, reducing the use of water in processing may contribute to a reduction in costs and emission of effluents. However, no consistent evidence in support of removing water during conveyor belt cleaning has been reported. Therefore, the objective of the present study was to compare the bacterial counts on conveyor belts that were or were not continuously cleaned with hot water under pressure. Superficial samples from conveyor belts (cleaned or not cleaned) were collected at three different times during operation (T1, after the preoperational cleaning [5 a.m.]; T2, after the first work shift [4 p.m.]; and T3, after the second work shift [1:30 a.m.]) in a poultry meat processing facility, and the samples were subjected to mesophilic and enterobacterial counts. For Enterobacteriaceae, no significant differences were observed between the conveyor belts, independent of the time of sampling or the cleaning process. No significant differences were observed between the counts of mesophilic bacteria at the distinct times of sampling on the conveyor belt that had not been subjected to continuous cleaning with water at 45°C. When comparing similar periods of sampling, no significant differences were observed between the mesophilic counts obtained from the conveyor belts that were or were not subjected to continuous cleaning with water at 45°C. Continuous cleaning with water did not significantly reduce microorganism counts, suggesting the possibility of discarding this procedure in chicken processing.

Benefits of integrating chemical and mechanical cleaning processes for steam generator sludge removal

International Nuclear Information System (INIS)

Varrin, R.D.; Ferriter, A.M.; Oliver, T.W.; Le Surf, J.E.

1992-01-01

This paper discusses the benefits of performing in-bundle tubesheet lancing in conjunction with chemical cleaning of PWR and PHWR steam generators in which a hard sludge pile is known to exist. The primary benefits of in-bundle lancing are to: (1) increase the exposed area of the sludge pile by cutting furrows in the surface thereby enhancing dissolution of sludge, (2) reduce the volume of solvents required since material removed by lancing does not have to be dissolved chemically, (3) improve rinsing and removal of residual solvent between iron and copper dissolution steps, and (4) allow for verification of process effectiveness by providing high quality in-bundle visual inspection. The reduction in solvent volumes can lead to a significant reduction in solvent costs and waste processing. A case study which includes an economic evaluation for a combined chemical and mechanical cleaning shows a potential cost saving of up to US$ 300,000 over use of chemical cleaning alone. 14 refs., 2 tabs., 2 figs

Evaluation of hydrogen and methane production from sugarcane bagasse hemicellulose hydrolysates by two-stage anaerobic digestion process.

Science.gov (United States)

Baêta, Bruno Eduardo Lobo; Lima, Diego Roberto Sousa; Filho, José Gabriel Balena; Adarme, Oscar Fernando Herrera; Gurgel, Leandro Vinícius Alves; Aquino, Sérgio Francisco de

2016-10-01

This study aimed at optimizing the net energy recovery from hydrogen and methane production through anaerobic digestion of the hemicellulose hydrolysate (HH) obtained by desirable conditions (DC) of autohydrolysis pretreatment (AH) of sugarcane bagasse (SB). Anaerobic digestion was carried out in a two-stage (acidogenic-methanogenic) batch system where the acidogenic phase worked as a hydrolysis and biodetoxification step. This allowed the utilization of more severe AH pretreatment conditions, i.e. T=178.6°C and t=55min (DC3) and T=182.9°C and t=40.71min (DC4). Such severe conditions resulted in higher extraction of hemicelluloses from SB (DC1=68.07%, DC2=48.99%, DC3=77.40% and DC4=73.90%), which consequently improved the net energy balance of the proposed process. The estimated energy from the combustion of both biogases (H2 and CH4) accumulated during the two-stage anaerobic digestion of HH generated by DC4 condition was capable of producing a net energy of 3.15MJ·kgSB(-1)dry weight. Copyright © 2016 Elsevier Ltd. All rights reserved.

A two-phase inspection model for a single component system with three-stage degradation

International Nuclear Information System (INIS)

Wang, Huiying; Wang, Wenbin; Peng, Rui

2017-01-01

This paper presents a two-phase inspection schedule and an age-based replacement policy for a single plant item contingent on a three-stage degradation process. The two phase inspection schedule can be observed in practice. The three stages are defined as the normal working stage, low-grade defective stage and critical defective stage. When an inspection detects that an item is in the low-grade defective stage, we may delay the preventive replacement action if the time to the age-based replacement is less than or equal to a threshold level. However, if it is above this threshold level, the item will be replaced immediately. If the item is found in the critical defective stage, it is replaced immediately. A hybrid bee colony algorithm is developed to find the optimal solution for the proposed model which has multiple decision variables. A numerical example is conducted to show the efficiency of this algorithm, and simulations are conducted to verify the correctness of the model. - Highlights: • A two-phase inspection model is studied. • The failure process has three stages. • The delayed replacement is considered.

Staging Collaborative Innovation Processes

DEFF Research Database (Denmark)

Pedersen, Signe; Clausen, Christian

Organisations are currently challenged by demands for increased collaborative innovation internally as well as with external and new entities - e.g. across the value chain. The authors seek to develop new approaches to managing collaborative innovative processes in the context of open innovation ...... the diverse matters of concern into a coherent product or service concept, and 2) in the same process move these diverse holders of the matters of concern into a translated actor network which carry or support the concept.......Organisations are currently challenged by demands for increased collaborative innovation internally as well as with external and new entities - e.g. across the value chain. The authors seek to develop new approaches to managing collaborative innovative processes in the context of open innovation...... and public private innovation partnerships. Based on a case study of a collaborative design process in a large electronics company the paper points to the key importance of staging and navigation of collaborative innovation process. Staging and navigation is presented as a combined activity: 1) to translate...

Lessons learned from a rigorous peer-review process for building the Climate Literacy and Energy Awareness (CLEAN) collection of high-quality digital teaching materials

Science.gov (United States)

Gold, A. U.; Ledley, T. S.; McCaffrey, M. S.; Buhr, S. M.; Manduca, C. A.; Niepold, F.; Fox, S.; Howell, C. D.; Lynds, S. E.

2010-12-01

The topic of climate change permeates all aspects of our society: the news, household debates, scientific conferences, etc. To provide students with accurate information about climate science and energy awareness, educators require scientifically and pedagogically robust teaching materials. To address this need, the NSF-funded Climate Literacy & Energy Awareness Network (CLEAN) Pathway has assembled a new peer-reviewed digital collection as part of the National Science Digital Library (NSDL) featuring teaching materials centered on climate and energy science for grades 6 through 16. The scope and framework of the collection is defined by the Essential Principles of Climate Science (CCSP 2009) and a set of energy awareness principles developed in the project. The collection provides trustworthy teaching materials on these socially relevant topics and prepares students to become responsible decision-makers. While a peer-review process is desirable for curriculum developer as well as collection builder to ensure quality, its implementation is non-trivial. We have designed a rigorous and transparent peer-review process for the CLEAN collection, and our experiences provide general guidelines that can be used to judge the quality of digital teaching materials across disciplines. Our multi-stage review process ensures that only resources with teaching goals relevant to developing climate literacy and energy awareness are considered. Each relevant resource is reviewed by two individuals to assess the i) scientific accuracy, ii) pedagogic effectiveness, and iii) usability/technical quality. A science review by an expert ensures the scientific quality and accuracy. Resources that pass all review steps are forwarded to a review panel of educators and scientists who make a final decision regarding inclusion of the materials in the CLEAN collection. Results from the first panel review show that about 20% (~100) of the resources that were initially considered for inclusion

Two-Stage Centrifugal Fan

Science.gov (United States)

Converse, David

2011-01-01

Fan designs are often constrained by envelope, rotational speed, weight, and power. Aerodynamic performance and motor electrical performance are heavily influenced by rotational speed. The fan used in this work is at a practical limit for rotational speed due to motor performance characteristics, and there is no more space available in the packaging for a larger fan. The pressure rise requirements keep growing. The way to ordinarily accommodate a higher DP is to spin faster or grow the fan rotor diameter. The invention is to put two radially oriented stages on a single disk. Flow enters the first stage from the center; energy is imparted to the flow in the first stage blades, the flow is redirected some amount opposite to the direction of rotation in the fixed stators, and more energy is imparted to the flow in the second- stage blades. Without increasing either rotational speed or disk diameter, it is believed that as much as 50 percent more DP can be achieved with this design than with an ordinary, single-stage centrifugal design. This invention is useful primarily for fans having relatively low flow rates with relatively high pressure rise requirements.

Clean energy utilization technology

International Nuclear Information System (INIS)

Honma, Takuya

1992-01-01

The technical development of clean energy including the utilization of solar energy was begun in 1973 at the time of the oil crisis, and about 20 years elapsed. Also in Japan, the electric power buying system by electric power companies for solar light electric power and wind electric power has been started in 1992, namely their value as a merchandise was recognized. As for these two technologies, the works of making the international standards and JIS were begun. The range of clean energy or natural energy is wide, and its kinds are many. The utilization of solar heat and the electric power generation utilizing waves, tide and geotherm already reached the stage of practical use. Generally in order to practically use new energy, the problem of price must be solved, but the price is largely dependent on the degree of spread. Also the reliability, durability and safety must be ensured, and the easiness of use, effectiveness and trouble-saving maintenance and operation are required. For the purpose, it is important to packaging those skillfully in a system. The cases of intelligent natural energy systems are shown. Solar light and wind electric power generation systems and the technology of transporting clean energy are described. (K.I.)

Evaluation of two recommended disinfection methods for cleaning cloths used in food services of southern Brazil.

Science.gov (United States)

Bartz, Sabrina; Tondo, Eduardo Cesar

2013-01-01

In the State of Rio Grande do Sul (RS), Southern Brazil, a good manufacturing practices regulation was published recommending two disinfection methods for cleaning cloths used in food services. The aim of the present study was to evaluate the efficacy of those methods. Cleaning cloths were sampled without prior notice at food services, on common working days. For the analyses, the cloths were divided in two sub-samples, being one of them microbiologically analyzed. The second sub-sample was further divided in two pieces and submitted to hand washing for two minutes. After that, one piece was boiled in water for 15 min and the other one was soaked in a 200 ppm sodium hypochlorite solution for 15 min. Both pieces of cloth were submitted to microbiological analyses. Cleaning cloths presented total aerobic mean counts of 6.9 ± 6.7 log/cm(2). All cleaning cloths presented coliform contamination, and 40% demonstrated mean counts of 6.2 ± 5.6 log/cm(2). Presumptive S. aureus mean counts of 5.5 ± 4.9 log/cm(2) were found. No statistic correlation was observed among the number of meals served daily in the food services and the microbiological contamination levels. After washing and disinfection, microbiological counts were significantly (p disinfect cleaning cloths used in food services.

Exploring the hole cleaning parameters of horizontal wellbore using two-phase Eulerian CFD approach

Directory of Open Access Journals (Sweden)

Satish K Dewangan

2016-03-01

Full Text Available The present investigation deals with the flow through concentric annulus with the inner cylinder in rotation. This work has got its importance in the petroleum industries in relation to the wellbore drilling. In wellbore drilling, the issue of the hole-cleaning is very serious problem especially in case of the horizontal drilling process. The effect of the various parameters like slurry flow velocity, inner cylinder rotational speed, inlet solid concentration which affect hole cleaning was discussed. Their effect on the pressure drop, wall shear stress, mixture turbulence kinetic energy, and solid-phase velocity and slip velocity were analyzed, which are responsible for solid-phase distribution. Flow was considered to be steady, incompressible and two-phase slurry flow with water as carrier fluid and silica sand as the secondary phase. Eulerian approach was used for modeling the slurry flow. Silica sand was considered of spherical shape with particle size of 180 µm. ANSYS FLUENT software was used for modeling and solution. Plotting was done using Tecplot software and Microsoft Office.

Tritium recovery from tritiated water with a two-stage palladium membrane reactor

International Nuclear Information System (INIS)

Birdsell, S.A.; Willms, R.S.

1997-01-01

A process to recover tritium from tritiated water has been successfully demonstrated at TSTA. The 2-stage palladium membrane reactor (PMR) is capable of recovering tritium from water without generating additional waste. This device can be used to recover tritium from the substantial amount of tritiated water that is expected to be generated in the International Thermonuclear Experimental Reactor both from torus exhaust and auxiliary operations. A large quantity of tritiated waste water exists world wide because the predominant method of cleaning up tritiated streams is to oxidize tritium to tritiated water. The latter can be collected with high efficiency for subsequent disposal. The PMR is a combined catalytic reactor/permeator. Cold (non-tritium) water processing experiments were run in preparation for the tritiated water processing tests. Tritium was recovered from a container of molecular sieve loaded with 2,050 g (2,550 std. L) of water and 4.5 g of tritium. During this experiment, 27% (694 std. L) of the water was processed resulting in recovery of 1.2 g of tritium. The maximum water processing rate for the PMR system used was determined to be 0.5 slpm. This correlates well with the maximum processing rate determined from the smaller PMR system on the cold test bench and has resulted in valuable scale-up and design information

Tritium recovery from tritiated water with a two-stage palladium membrane reactor

Energy Technology Data Exchange (ETDEWEB)

Birdsell, S.A.; Willms, R.S.

1997-04-01

A process to recover tritium from tritiated water has been successfully demonstrated at TSTA. The 2-stage palladium membrane reactor (PMR) is capable of recovering tritium from water without generating additional waste. This device can be used to recover tritium from the substantial amount of tritiated water that is expected to be generated in the International Thermonuclear Experimental Reactor both from torus exhaust and auxiliary operations. A large quantity of tritiated waste water exists world wide because the predominant method of cleaning up tritiated streams is to oxidize tritium to tritiated water. The latter can be collected with high efficiency for subsequent disposal. The PMR is a combined catalytic reactor/permeator. Cold (non-tritium) water processing experiments were run in preparation for the tritiated water processing tests. Tritium was recovered from a container of molecular sieve loaded with 2,050 g (2,550 std. L) of water and 4.5 g of tritium. During this experiment, 27% (694 std. L) of the water was processed resulting in recovery of 1.2 g of tritium. The maximum water processing rate for the PMR system used was determined to be 0.5 slpm. This correlates well with the maximum processing rate determined from the smaller PMR system on the cold test bench and has resulted in valuable scale-up and design information.

Capillary-Force-Assisted Clean-Stamp Transfer of Two-Dimensional Materials.

Science.gov (United States)

Ma, Xuezhi; Liu, Qiushi; Xu, Da; Zhu, Yangzhi; Kim, Sanggon; Cui, Yongtao; Zhong, Lanlan; Liu, Ming

2017-11-08

A simple and clean method of transferring two-dimensional (2D) materials plays a critical role in the fabrication of 2D electronics, particularly the heterostructure devices based on the artificial vertical stacking of various 2D crystals. Currently, clean transfer techniques rely on sacrificial layers or bulky crystal flakes (e.g., hexagonal boron nitride) to pick up the 2D materials. Here, we develop a capillary-force-assisted clean-stamp technique that uses a thin layer of evaporative liquid (e.g., water) as an instant glue to increase the adhesion energy between 2D crystals and polydimethylsiloxane (PDMS) for the pick-up step. After the liquid evaporates, the adhesion energy decreases, and the 2D crystal can be released. The thin liquid layer is condensed to the PDMS surface from its vapor phase, which ensures the low contamination level on the 2D materials and largely remains their chemical and electrical properties. Using this method, we prepared graphene-based transistors with low charge-neutral concentration (3 × 10 10 cm -2 ) and high carrier mobility (up to 48 820 cm 2 V -1 s -1 at room temperature) and heterostructure optoelectronics with high operation speed. Finally, a capillary-force model is developed to explain the experiment.

Characterization of microbial community in the two-stage process for hydrogen and methane production from food waste

Energy Technology Data Exchange (ETDEWEB)

Chu, Chun-Feng [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Ebie, Yoshitaka [National Institute for Environmental Studies, Tsukuba 305-8506 (Japan); Xu, Kai-Qin [National Institute for Environmental Studies, Tsukuba 305-8506 (Japan); State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072 (China); Li, Yu-You [Department of Civil and Environmental Engineering, Tohoku University, Sendai 980-8579 (Japan); Inamori, Yuhei [Faculty of Symbiotic Systems Science, Fukushima University, Fukushima 960-1296 (Japan)

2010-08-15

The structure of a microbial community in the two-stage process for H{sub 2} and CH{sub 4} production from food waste was investigated by a molecular biological approach. The process was a continuous combined thermophilic acidogenic hydrogenesis and mesophilic (RUN1) or thermophilic (RUN2) methanogenesis with recirculation of the digested sludge. A two-phase process suggested in this study effectively separate H{sub 2}-producing bacteria from methanogenic archaea by optimization of design parameters such as pH, hydraulic retention time (HRT) and temperature. Galore microbial diversity was found in the thermophilic acidogenic hydrogenesis, Clostridium sp. strain Z6 and Thermoanaerobacterium thermosaccharolyticum were considered to be the dominant thermophilic H{sub 2}-producing bacteria. The hydrogenotrophic methanogens were inhibited in thermophilic methanogenesis, whereas archaeal rDNAs were higher in the thermophilic methanogenesis than those in mesophilic methanogenesis. The yields of H{sub 2} and CH{sub 4} were in equal range depending on the characteristics of food waste, whereas effluent water quality indicators were different obviously in RUN1 and RUN2. The results indicated that hydrolysis and removal of food waste were higher in RUN2 than RUN1. (author)

Feasibility of a two-stage biological aerated filter for depth processing of electroplating-wastewater.

Science.gov (United States)

Liu, Bo; Yan, Dongdong; Wang, Qi; Li, Song; Yang, Shaogui; Wu, Wenfei

2009-09-01

A "two-stage biological aerated filter" (T-SBAF) consisting of two columns in series was developed to treat electroplating-wastewater. Due to the low BOD/CODcr values of electroplating-wastewater, "twice start-up" was employed to reduce the time for adaptation of microorganisms, a process that takes up of 20 days. Under steady-state conditions, the removal of CODcr and NH(4)(+)-N increased first and then decreased while the hydraulic loadings increased from 0.75 to 1.5 m(3) m(-2) h(-1). The air/water ratio had the same influence on the removal of CODcr and NH(4)(+)-N when increasing from 3:1 to 6:1. When the hydraulic loadings and air/water ratio were 1.20 m(3) m(-2) h(-1) and 4:1, the optimal removal of CODcr, NH(4)(+)-N and total-nitrogen (T-N) were 90.13%, 92.51% and 55.46%, respectively. The effluent steadily reached the wastewater reuse standard. Compared to the traditional BAF, the period before backwashing of the T-SBAF could be extended to 10days, and the recovery time was considerably shortened.

Flue Gas Cleaning With Alternative Processes and Reaction Media

DEFF Research Database (Denmark)

Rasmussen, Søren Birk; Huang, Jun; Riisager, Anders

2007-01-01

Alternative methods to the traditional industrial NOX and SOXflue gas cleaning processes working at lower temperatures and/orleading to useful products are desired. In this work we presentour latest results regarding the use of molten ionic media inelectrocatalytic membrane separation, ionic liquid...... reversibleabsorption and supported ionic liquid deNOX catalysis. Furtherdevelopment of the methods will hopefully make them suitable forinstallation in different positions in the flue gas duct ascompared to the industrial methods available today....

A study on the chemical cleaning process and its qualification test by eddy current testing

Energy Technology Data Exchange (ETDEWEB)

Shin, Ki Seok; Cheon, Keun Young; Nam, Min Woo [KHNP Central Research Institute, Daejeon (Korea, Republic of); Min, Kyoung Mahn [UMI Inc., Daejeon (Korea, Republic of)

2013-12-15

Steam Generator (SG) tube, as a barrier isolating the primary coolant system from the secondary side of nuclear power plants (NPP), must maintain the structural integrity for the public safety and their efficient power generation. So, SG tubes are subject to the periodic examination and the repairs if needed so that any defective tubes are not in service. Recently, corrosion related degradations were detected in the tubes of the domestic OPR-1000 NPP, as a form of axially oriented outer diameter stress corrosion cracking (ODSCC). According to the studies on the factors causing the heat fouling as well as developing corrosion cracking, densely scaled deposits on the secondary side of the SG tubes are mainly known to be problematic causing the adverse impacts against the soundness of the SG tubes. Therefore, the processes of various cleaning methods efficiently to dissolve and remove the deposits have been applied as well as it is imperative to maintain the structural integrity of the tubes after exposing to the cleaning agent. So qualification test (QT) should be carried out to assess the perfection of the chemical cleaning and QT is to apply the processes and to do ECT. In this paper, the chemical cleaning processes to dissolve and remove the scaled deposits are introduced and results of ECT on the artificial crack specimens to determine the effectiveness of those processes are represented.

Effects of Two-stage Controlled pH and Temperature vs. One-step Process for Hemicellulase Biosynthesis and Feruloyl Oligosaccharide Fermentation using Aureobasidium pullulans

Directory of Open Access Journals (Sweden)

Xiaohong Yu

2016-04-01

Full Text Available A two-stage, pH- and temperature-controlled wheat bran fermentation method using Aureobasidium pullulans was investigated for feruloyl oligosaccharides (FOs production and the activities of xylanase, xylosidase, and ferulic acid esterase (FAE. A. pullulans secreted xylanase, xylosidase, and FAE at high levels in the initial pH of 4.0 to 5.0 and a fermentation liquid temperature of 31 °C to 33 °C. FOs production via two-stage fermentation (FOs 2 reached 1123 nmol/L after fermentation for 96 h, by controlling the initial pH at 4.0 and the initial temperature at 33 °C, and then changing the pH to 6.0 and the temperature to 29 °C at the same time at 36 h. This process was 12 h shorter and 219 nmol/L higher than a one-stage fermentation for producing FOs 1. Xylanase, xylosidase, and FAE activities were highly correlated with controlled pH and temperature and FOs biosynthesis rate. Thus, the combination of two-stage controlled pH and temperature could support mass production of FOs.

Comparison of high-intensity sound and mechanical vibration for cleaning porous titanium cylinders fabricated using selective laser melting.

Science.gov (United States)

Seiffert, Gary; Hopkins, Carl; Sutcliffe, Chris

2017-01-01

Orthopedic components, such as the acetabular cup in total hip joint replacement, can be fabricated using porous metals, such as titanium, and a number of processes, such as selective laser melting. The issue of how to effectively remove loose powder from the pores (residual powder) of such components has not been addressed in the literature. In this work, we investigated the feasibility of two processes, acoustic cleaning using high-intensity sound inside acoustic horns and mechanical vibration, to remove residual titanium powder from selective laser melting-fabricated cylinders. With acoustic cleaning, the amount of residual powder removed was not influenced by either the fundamental frequency of the horn used (75 vs. 230 Hz) or, for a given horn, the number of soundings (between 1 and 20). With mechanical vibration, the amount of residual powder removed was not influenced by the application time (10 vs. 20 s). Acoustic cleaning was found to be more reliable and effective in removal of residual powder than cleaning with mechanical vibration. It is concluded that acoustic cleaning using high-intensity sound has significant potential for use in the final preparation stages of porous metal orthopedic components. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 117-123, 2017. © 2015 The Authors Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc.

In-Water Hull Cleaning & Filtration System

Science.gov (United States)

George, Dan

2015-04-01

through a multi stage filtration unit on the surface. Solids greater than 50 micron are separated through a 1st stage separator and deposited into a disposal bin. Filtrate is then pumped through a series of high flow, back-flushable filters that remove particulate material greater than 5 micron. After the 1st and 2nd stage filtration the filtrate is then disinfected by passing through an automated UV reactor where the treated water is then released back into the ocean. This advancement in hull cleaning technology will allow vessels to be cleaned in areas where dry docking is not possible or viable along with being a preventive measure to reduce Biofouling in the environment. The in-water hull cleaning system certainly has earned its place as being an innovative leader in improving efficiencies and reducing environmental impact. https://www.linkedin.com/groups?mostRecent=&gid=6724648&trk=my_groups-tile-flipgrp

Clean Restructuring: Design Elements for Low Carbon Wholesale Markets and Beyond

Energy Technology Data Exchange (ETDEWEB)

None, None

2016-05-01

Countries around the world are in various stages of power system reform and restructuring to more effectively meet development goals and decarbonization commitments. Changes in social dynamics, technology, business models, and environmental goals are increasing pressure for countries to consider improvements to their power systems. This brochure overviews the 21st Century Power Partnerships thought leadership report that explores the clean restructuring pathway in depth, envisions an end state, and articulates three main areas of consideration for decision makers embarking on a clean restructuring process. The report also details case studies from Germany, Denmark, and Mexico.

Assessing efficiency and effectiveness of Malaysian Islamic banks: A two stage DEA analysis

Science.gov (United States)

Kamarudin, Norbaizura; Ismail, Wan Rosmanira; Mohd, Muhammad Azri

2014-06-01

Islamic banks in Malaysia are indispensable players in the financial industry with the growing needs for syariah compliance system. In the banking industry, most recent studies concerned only on operational efficiency. However rarely on the operational effectiveness. Since the production process of banking industry can be described as a two-stage process, two-stage Data Envelopment Analysis (DEA) can be applied to measure the bank performance. This study was designed to measure the overall performance in terms of efficiency and effectiveness of Islamic banks in Malaysia using Two-Stage DEA approach. This paper presents analysis of a DEA model which split the efficiency and effectiveness in order to evaluate the performance of ten selected Islamic Banks in Malaysia for the financial year period ended 2011. The analysis shows average efficient score is more than average effectiveness score thus we can say that Malaysian Islamic banks were more efficient rather than effective. Furthermore, none of the bank exhibit best practice in both stages as we can say that a bank with better efficiency does not always mean having better effectiveness at the same time.

Decentralized enforcement, sequential bargaining, and the clean development mechanism

Energy Technology Data Exchange (ETDEWEB)

Hovi, Jon

2001-07-01

While there is a vast literature both on international bargaining and on how international agreements can be enforced, very little work has been done on how bargaining and enforcement interact. An important exception is Fearon (1998), who models international cooperation as a two-stage process in which the bargaining process is constrained by a need for decentralized enforcement (meaning that the agreement must be enforced by the parties themselves rather than a third party, such as a court). Using the Clean Development Mechanism as an example, the present paper proposes a different model of this kind of interaction. The model follows Fearon's in so far as we both use the infinitely repeated Prisoners' Dilemma to capture the enforcement phase of the game. However, while Fearon depicts the bargaining stage as a War of Attrition, the present model sees that stage as a sequential bargaining game of the Staahl-Rubinstein type. The implications of the present model are compared both to those of the Staahl-Rubinstein model and to those of the Fearon model. A surprising conclusion is that a need for decentralized enforcement tends to make the bargaining outcome more symmetrical than otherwise. Thus, the impact of bargaining power is actually smaller when the resulting agreement must be enforced by the parties themselves than it is if enforcement is taken care of by a third party. (author)

Preferential processing of self-relevant stimuli occurs mainly at the perceptual and conscious stages of information processing.

Science.gov (United States)

Tacikowski, P; Ehrsson, H H

2016-04-01

Self-related stimuli, such as one's own name or face, are processed faster and more accurately than other types of stimuli. However, what remains unknown is at which stage of the information processing hierarchy this preferential processing occurs. Our first aim was to determine whether preferential self-processing involves mainly perceptual stages or also post-perceptual stages. We found that self-related priming was stronger than other-related priming only because of perceptual prime-target congruency. Our second aim was to dissociate the role of conscious and unconscious factors in preferential self-processing. To this end, we compared the "self" and "other" conditions in trials where primes were masked or unmasked. In two separate experiments, we found that self-related priming was stronger than other-related priming but only in the unmasked trials. Together, our results suggest that preferential access to the self-concept occurs mainly at the perceptual and conscious stages of the stimulus processing hierarchy. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Two-stage categorization in brand extension evaluation: electrophysiological time course evidence.

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Qingguo Ma

Full Text Available A brand name can be considered a mental category. Similarity-based categorization theory has been used to explain how consumers judge a new product as a member of a known brand, a process called brand extension evaluation. This study was an event-related potential study conducted in two experiments. The study found a two-stage categorization process reflected by the P2 and N400 components in brand extension evaluation. In experiment 1, a prime-probe paradigm was presented in a pair consisting of a brand name and a product name in three conditions, i.e., in-category extension, similar-category extension, and out-of-category extension. Although the task was unrelated to brand extension evaluation, P2 distinguished out-of-category extensions from similar-category and in-category ones, and N400 distinguished similar-category extensions from in-category ones. In experiment 2, a prime-probe paradigm with a related task was used, in which product names included subcategory and major-category product names. The N400 elicited by subcategory products was more significantly negative than that elicited by major-category products, with no salient difference in P2. We speculated that P2 could reflect the early low-level and similarity-based processing in the first stage, whereas N400 could reflect the late analytic and category-based processing in the second stage.

Evaluation of two recommended disinfection methods for cleaning cloths used in food services of southern Brazil

Directory of Open Access Journals (Sweden)

Sabrina Bartz

2013-09-01

Full Text Available In the State of Rio Grande do Sul (RS, Southern Brazil, a good manufacturing practices regulation was published recommending two disinfection methods for cleaning cloths used in food services. The aim of the present study was to evaluate the efficacy of those methods. Cleaning cloths were sampled without prior notice at food services, on common working days. For the analyses, the cloths were divided in two sub-samples, being one of them microbiologically analyzed. The second sub-sample was further divided in two pieces and submitted to hand washing for two minutes. After that, one piece was boiled in water for 15 min and the other one was soaked in a 200 ppm sodium hypochlorite solution for 15 min. Both pieces of cloth were submitted to microbiological analyses. Cleaning cloths presented total aerobic mean counts of 6.9 ± 6.7 log/cm². All cleaning cloths presented coliform contamination, and 40% demonstrated mean counts of 6.2 ± 5.6 log/cm². Presumptive S. aureus mean counts of 5.5 ± 4.9 log/cm² were found. No statistic correlation was observed among the number of meals served daily in the food services and the microbiological contamination levels. After washing and disinfection, microbiological counts were significantly (p < 0.05 reduced by both methods, achieving an approximately 5 log reduction. The reductions achieved by the sodium hypochlorite soaking method and the boiling method were not significantly different. Thus, it was possible to conclude that both recommended methods were suitable to disinfect cleaning cloths used in food services.

Two-stage collaborative global optimization design model of the CHPG microgrid

Science.gov (United States)

Liao, Qingfen; Xu, Yeyan; Tang, Fei; Peng, Sicheng; Yang, Zheng

2017-06-01

With the continuous developing of technology and reducing of investment costs, renewable energy proportion in the power grid is becoming higher and higher because of the clean and environmental characteristics, which may need more larger-capacity energy storage devices, increasing the cost. A two-stage collaborative global optimization design model of the combined-heat-power-and-gas (abbreviated as CHPG) microgrid is proposed in this paper, to minimize the cost by using virtual storage without extending the existing storage system. P2G technology is used as virtual multi-energy storage in CHPG, which can coordinate the operation of electric energy network and natural gas network at the same time. Demand response is also one kind of good virtual storage, including economic guide for the DGs and heat pumps in demand side and priority scheduling of controllable loads. Two kinds of storage will coordinate to smooth the high-frequency fluctuations and low-frequency fluctuations of renewable energy respectively, and achieve a lower-cost operation scheme simultaneously. Finally, the feasibility and superiority of proposed design model is proved in a simulation of a CHPG microgrid.

Anaerobic digestion of citrus waste using two-stage membrane bioreactor

Science.gov (United States)

Millati, Ria; Lukitawesa; Dwi Permanasari, Ervina; Wulan Sari, Kartika; Nur Cahyanto, Muhammad; Niklasson, Claes; Taherzadeh, Mohammad J.

2018-03-01

Anaerobic digestion is a promising method to treat citrus waste. However, the presence of limonene in citrus waste inhibits anaerobic digestion process. Limonene is an antimicrobial compound and could inhibit methane forming bacteria that takes a longer time to recover than the injured acid forming bacteria. Hence, volatile fatty acids will be accumulated and methane production will be decreased. One way to solve this problem is by conducting anaerobic digestion process into two stages. The first step is aimed for hydrolysis, acidogenesis, and acetogenesis reactions and the second stage is aimed for methanogenesis reaction. The separation of the system would further allow each stage in their optimum conditions making the process more stable. In this research, anaerobic digestion was carried out in batch operations using 120 ml-glass bottle bioreactors in 2 stages. The first stage was performed in free-cells bioreactor, whereas the second stage was performed in both bioreactor of free cells and membrane bioreactor. In the first stage, the reactor was set into ‘anaerobic’ and ‘semi-aerobic’ conditions to examine the effect of oxygen on facultative anaerobic bacteria in acid production. In the second stage, the protection of membrane towards the cells against limonene was tested. For the first stage, the basal medium was prepared with 1.5 g VS of inoculum and 4.5 g VS of citrus waste. The digestion process was carried out at 55°C for four days. For the second stage, the membrane bioreactor was prepared with 3 g of cells that were encased and sealed in a 3×6 cm2 polyvinylidene fluoride membrane. The medium contained 40 ml basal medium and 10 ml liquid from the first stage. The bioreactors were incubated at 55°C for 2 days under anaerobic condition. The results from the first stage showed that the maximum total sugar under ‘anaerobic’ and ‘semi-aerobic’ conditions was 294.3 g/l and 244.7 g/l, respectively. The corresponding values for total volatile

Two-stage, high power X-band amplifier experiment

International Nuclear Information System (INIS)

Kuang, E.; Davis, T.J.; Ivers, J.D.; Kerslick, G.S.; Nation, J.A.; Schaechter, L.

1993-01-01

At output powers in excess of 100 MW the authors have noted the development of sidebands in many TWT structures. To address this problem an experiment using a narrow bandwidth, two-stage TWT is in progress. The TWT amplifier consists of a dielectric (e = 5) slow-wave structure, a 30 dB sever section and a 8.8-9.0 GHz passband periodic, metallic structure. The electron beam used in this experiment is a 950 kV, 1 kA, 50 ns pencil beam propagating along an applied axial field of 9 kG. The dielectric first stage has a maximum gain of 30 dB measured at 8.87 GHz, with output powers of up to 50 MW in the TM 01 mode. In these experiments the dielectric amplifier output power is about 3-5 MW and the output power of the complete two-stage device is ∼160 MW at the input frequency. The sidebands detected in earlier experiments have been eliminated. The authors also report measurements of the energy spread of the electron beam resulting from the amplification process. These experimental results are compared with MAGIC code simulations and analytic work they have carried out on such devices

Second stage gasifier in staged gasification and integrated process

Science.gov (United States)

Liu, Guohai; Vimalchand, Pannalal; Peng, Wan Wang

2015-10-06

A second stage gasification unit in a staged gasification integrated process flow scheme and operating methods are disclosed to gasify a wide range of low reactivity fuels. The inclusion of second stage gasification unit operating at high temperatures closer to ash fusion temperatures in the bed provides sufficient flexibility in unit configurations, operating conditions and methods to achieve an overall carbon conversion of over 95% for low reactivity materials such as bituminous and anthracite coals, petroleum residues and coke. The second stage gasification unit includes a stationary fluidized bed gasifier operating with a sufficiently turbulent bed of predefined inert bed material with lean char carbon content. The second stage gasifier fluidized bed is operated at relatively high temperatures up to 1400.degree. C. Steam and oxidant mixture can be injected to further increase the freeboard region operating temperature in the range of approximately from 50 to 100.degree. C. above the bed temperature.

Containment air cleaning for LMFBRs

International Nuclear Information System (INIS)

Hilliard, R.K.; McCormack, J.D.; Owen, R.K.; Postma, A.K.

1979-01-01

A variety of air cleaning concepts was evaluated for potential use in future sodium-cooled breeder reactors. A 3-stage aqueous scrubber system was selected for large-scale demonstration testing under conditions similar to those postulated for containment venting and purging during reactor melt-through accidents. Two tests were performed in the Containment Systems Test Facility using a quench tank, a jet venturi scrubber and a high efficiency fibrous scrubber in series. The results of two tests with Na/sub 2/O/sub 2/ and NaOH aerosol and NaI vapor are presented showing >99.9% removal of Na/sub 2/O/sub 2/ and NaOH and >99.7% for NaI. 7 refs

Effective conversion of maize straw wastes into bio-hydrogen by two-stage process integrating H2 fermentation and MECs.

Science.gov (United States)

Li, Yan-Hong; Bai, Yan-Xia; Pan, Chun-Mei; Li, Wei-Wei; Zheng, Hui-Qin; Zhang, Jing-Nan; Fan, Yao-Ting; Hou, Hong-Wei

2015-12-01

The enhanced H2 production from maize straw had been achieved through the two-stage process of integrating H2 fermentation and microbial electrolysis cells (MECs) in the present work. Several key parameters affecting hydrolysis of maize straw through subcritical H2O were optimized by orthogonal design for saccharification of maize straw followed by H2 production through H2 fermentation. The maximum reducing sugar (RS) content of maize straw reached 469.7 mg/g-TS under the optimal hydrolysis condition with subcritical H2O combining with dilute HCl of 0.3% at 230 °C. The maximum H2 yield, H2 production rate, and H2 content was 115.1 mL/g-TVS, 2.6 mL/g-TVS/h, and 48.9% by H2 fermentation, respectively. In addition, the effluent from H2 fermentation was used as feedstock of MECs for additional H2 production. The maximum H2 yield of 1060 mL/g-COD appeared at an applied voltage of 0.8 V, and total COD removal reached about 35%. The overall H2 yield from maize straw reached 318.5 mL/g-TVS through two-stage processes. The structural characterization of maize straw was also carefully investigated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) spectra.

Optimization of a novel enzyme treatment process for early-stage processing of sheepskins.

Science.gov (United States)

Lim, Y F; Bronlund, J E; Allsop, T F; Shilton, A N; Edmonds, R L

2010-01-01

An enzyme treatment process for early-stage processing of sheepskins has been previously reported by the Leather and Shoe Research Association of New Zealand (LASRA) as an alternative to current industry operations. The newly developed process had marked benefits over conventional processing in terms of a lowered energy usage (73%), processing time (47%) as well as water use (49%), but had been developed as a "proof of principle''. The objective of this work was to develop the process further to a stage ready for adoption by industry. Mass balancing was used to investigate potential modifications for the process based on the understanding developed from a detailed analysis of preliminary design trials. Results showed that a configuration utilising a 2 stage counter-current system for the washing stages and segregation and recycling of enzyme float prior to dilution in the neutralization stage was a significant improvement. Benefits over conventional processing include a reduction of residual TDS by 50% at the washing stages and 70% savings on water use overall. Benefits over the un-optimized LASRA process are reduction of solids in product after enzyme treatment and neutralization stages by 30%, additional water savings of 21%, as well as 10% savings of enzyme usage.

Two-stage free electron laser research

Science.gov (United States)

Segall, S. B.

1984-10-01

KMS Fusion, Inc. began studying the feasibility of two-stage free electron lasers for the Office of Naval Research in June, 1980. At that time, the two-stage FEL was only a concept that had been proposed by Luis Elias. The range of parameters over which such a laser could be successfully operated, attainable power output, and constraints on laser operation were not known. The primary reason for supporting this research at that time was that it had the potential for producing short-wavelength radiation using a relatively low voltage electron beam. One advantage of a low-voltage two-stage FEL would be that shielding requirements would be greatly reduced compared with single-stage short-wavelength FEL's. If the electron energy were kept below about 10 MeV, X-rays, generated by electrons striking the beam line wall, would not excite neutron resonance in atomic nuclei. These resonances cause the emission of neutrons with subsequent induced radioactivity. Therefore, above about 10 MeV, a meter or more of concrete shielding is required for the system, whereas below 10 MeV, a few millimeters of lead would be adequate.

What makes us think? A three-stage dual-process model of analytic engagement.

Science.gov (United States)

Pennycook, Gordon; Fugelsang, Jonathan A; Koehler, Derek J

2015-08-01

The distinction between intuitive and analytic thinking is common in psychology. However, while often being quite clear on the characteristics of the two processes ('Type 1' processes are fast, autonomous, intuitive, etc. and 'Type 2' processes are slow, deliberative, analytic, etc.), dual-process theorists have been heavily criticized for being unclear on the factors that determine when an individual will think analytically or rely on their intuition. We address this issue by introducing a three-stage model that elucidates the bottom-up factors that cause individuals to engage Type 2 processing. According to the model, multiple Type 1 processes may be cued by a stimulus (Stage 1), leading to the potential for conflict detection (Stage 2). If successful, conflict detection leads to Type 2 processing (Stage 3), which may take the form of rationalization (i.e., the Type 1 output is verified post hoc) or decoupling (i.e., the Type 1 output is falsified). We tested key aspects of the model using a novel base-rate task where stereotypes and base-rate probabilities cued the same (non-conflict problems) or different (conflict problems) responses about group membership. Our results support two key predictions derived from the model: (1) conflict detection and decoupling are dissociable sources of Type 2 processing and (2) conflict detection sometimes fails. We argue that considering the potential stages of reasoning allows us to distinguish early (conflict detection) and late (decoupling) sources of analytic thought. Errors may occur at both stages and, as a consequence, bias arises from both conflict monitoring and decoupling failures. Copyright © 2015 Elsevier Inc. All rights reserved.

[Cleaning and disinfection of surfaces in hospitals: Data on structure, process and result in the Frankfurt/Main Metropolitan Area].

Science.gov (United States)

Hausemann, A; Hofmann, H; Otto, U; Heudorf, Ursel

2015-06-01

In addition to hand hygiene and reprocessing of medical products, cleaning and disinfection of surfaces is also an important issue in the prevention of germ transmission and by implication infections. Therefore, in 2014, the quality of the structure, process and result of surface preparation of all hospitals in Frankfurt am Main, Germany, was monitored. All 17 hospitals transferred information on the quality of structure. Process quality was obtained through direct observation during cleaning and disinfection of rooms and their plumbing units. Result quality was gained using the fluorescent method, i.e. marking surfaces with a fluorescent liquid and testing if this mark has been sufficiently removed by cleaning. Structure quality: in all hospitals the employees were trained regularly. In 12 of them, the foremen had the required qualifications, in 6 hospitals unclarity as to the intersection of the cleaning and care services remained. In 14 hospitals only visible contamination was cleaned on the weekends, whereas complete cleaning was reported to take place in 12 hospitals on Saturdays and in 2 hospitals on Sundays. The contractually stipulated cleaning (observations specified in brackets) averaged 178 m(2)/h (148 m(2)/h) per patient room and 69 m(2)/h (33 m(2)/h) for bathrooms. Process quality: during process monitoring, various hand contact surfaces were prepared insufficiently. Result quality: 63 % of fluorescent markings were appropriately removed. The need for improvement is given especially in the area of the qualification of the foremen and a in a clear definition of the intersection between cleaning and care services, as well as in the regulations for weekends and public holidays.

Continuous production of biohythane from hydrothermal liquefied cornstalk biomass via two-stage high-rate anaerobic reactors.

Science.gov (United States)

Si, Bu-Chun; Li, Jia-Ming; Zhu, Zhang-Bing; Zhang, Yuan-Hui; Lu, Jian-Wen; Shen, Rui-Xia; Zhang, Chong; Xing, Xin-Hui; Liu, Zhidan

2016-01-01

Biohythane production via two-stage fermentation is a promising direction for sustainable energy recovery from lignocellulosic biomass. However, the utilization of lignocellulosic biomass suffers from specific natural recalcitrance. Hydrothermal liquefaction (HTL) is an emerging technology for the liquefaction of biomass, but there are still several challenges for the coupling of HTL and two-stage fermentation. One particular challenge is the limited efficiency of fermentation reactors at a high solid content of the treated feedstock. Another is the conversion of potential inhibitors during fermentation. Here, we report a novel strategy for the continuous production of biohythane from cornstalk through the integration of HTL and two-stage fermentation. Cornstalk was converted to solid and liquid via HTL, and the resulting liquid could be subsequently fed into the two-stage fermentation systems. The systems consisted of two typical high-rate reactors: an upflow anaerobic sludge blanket (UASB) and a packed bed reactor (PBR). The liquid could be efficiently converted into biohythane via the UASB and PBR with a high density of microbes at a high organic loading rate. Biohydrogen production decreased from 2.34 L/L/day in UASB (1.01 L/L/day in PBR) to 0 L/L/day as the organic loading rate (OLR) of the HTL liquid products increased to 16 g/L/day. The methane production rate achieved a value of 2.53 (UASB) and 2.54 L/L/day (PBR), respectively. The energy and carbon recovery of the integrated HTL and biohythane fermentation system reached up to 79.0 and 67.7%, respectively. The fermentation inhibitors, i.e., 5-hydroxymethyl furfural (41.4-41.9% of the initial quantity detected) and furfural (74.7-85.0% of the initial quantity detected), were degraded during hydrogen fermentation. Compared with single-stage fermentation, the methane process during two-stage fermentation had a more efficient methane production rate, acetogenesis, and COD removal. The microbial distribution

Automated cleaning and pre-processing of immunoglobulin gene sequences from high-throughput sequencing

Directory of Open Access Journals (Sweden)

Miri eMichaeli

2012-12-01

Full Text Available High throughput sequencing (HTS yields tens of thousands to millions of sequences that require a large amount of pre-processing work to clean various artifacts. Such cleaning cannot be performed manually. Existing programs are not suitable for immunoglobulin (Ig genes, which are variable and often highly mutated. This paper describes Ig-HTS-Cleaner (Ig High Throughput Sequencing Cleaner, a program containing a simple cleaning procedure that successfully deals with pre-processing of Ig sequences derived from HTS, and Ig-Indel-Identifier (Ig Insertion – Deletion Identifier, a program for identifying legitimate and artifact insertions and/or deletions (indels. Our programs were designed for analyzing Ig gene sequences obtained by 454 sequencing, but they are applicable to all types of sequences and sequencing platforms. Ig-HTS-Cleaner and Ig-Indel-Identifier have been implemented in Java and saved as executable JAR files, supported on Linux and MS Windows. No special requirements are needed in order to run the programs, except for correctly constructing the input files as explained in the text. The programs' performance has been tested and validated on real and simulated data sets.

Chemical cleaning review

International Nuclear Information System (INIS)

Dow, B.L.; Thomas, R.C.

1995-01-01

Three main chemical processes for cleaning steam generators have evolved from the early work of the industry. Of the more than 50 chemical cleanings carried out to date most have been considered a success by the utilities performing them. (author)

Two stage treatment of dairy effluent using immobilized Chlorella pyrenoidosa

Science.gov (United States)

2013-01-01

Background Dairy effluents contains high organic load and unscrupulous discharge of these effluents into aquatic bodies is a matter of serious concern besides deteriorating their water quality. Whilst physico-chemical treatment is the common mode of treatment, immobilized microalgae can be potentially employed to treat high organic content which offer numerous benefits along with waste water treatment. Methods A novel low cost two stage treatment was employed for the complete treatment of dairy effluent. The first stage consists of treating the diary effluent in a photobioreactor (1 L) using immobilized Chlorella pyrenoidosa while the second stage involves a two column sand bed filtration technique. Results Whilst NH4+-N was completely removed, a 98% removal of PO43--P was achieved within 96 h of two stage purification processes. The filtrate was tested for toxicity and no mortality was observed in the zebra fish which was used as a model at the end of 96 h bioassay. Moreover, a significant decrease in biological oxygen demand and chemical oxygen demand was achieved by this novel method. Also the biomass separated was tested as a biofertilizer to the rice seeds and a 30% increase in terms of length of root and shoot was observed after the addition of biomass to the rice plants. Conclusions We conclude that the two stage treatment of dairy effluent is highly effective in removal of BOD and COD besides nutrients like nitrates and phosphates. The treatment also helps in discharging treated waste water safely into the receiving water bodies since it is non toxic for aquatic life. Further, the algal biomass separated after first stage of treatment was highly capable of increasing the growth of rice plants because of nitrogen fixation ability of the green alga and offers a great potential as a biofertilizer. PMID:24355316

Processing method of radioactive cleaning drain

International Nuclear Information System (INIS)

Otsuka, Shigemitsu; Murakami, Tadashi; Kitao, Hideo

1998-01-01

Upon processing of radioactive cleaning drains, contained Co-60 is removed by a selectively adsorbing adsorbent. In addition, after removing suspended materials by a filtering device, Co-60 as predominant nuclides in the drain is selectively adsorbed. The concentration of objective Co-60 is in the order of 0.1 Bq/cc, and non-radioactive metal ions such as Na + ions are present in the order of ppm in addition to Co-60. A granular adsorbent for selectively adsorbing Co-60 is oxine-added activated carbon, and has a grain size of from 20 to 48 mesh. The granular adsorbent is used while being filled in an adsorbing tower. Since a relatively simple device comprising the filtering device and the adsorbing tower in combination is provided, the reduction of the construction cost can be expected. In addition, since no filtering aid is used in the filtering device, the amount of secondary wastes is small. (N.H.)

A stage is a stage is a stage: a direct comparison of two scoring systems.

Science.gov (United States)

Dawson, Theo L

2003-09-01

L. Kohlberg (1969) argued that his moral stages captured a developmental sequence specific to the moral domain. To explore that contention, the author compared stage assignments obtained with the Standard Issue Scoring System (A. Colby & L. Kohlberg, 1987a, 1987b) and those obtained with a generalized content-independent stage-scoring system called the Hierarchical Complexity Scoring System (T. L. Dawson, 2002a), on 637 moral judgment interviews (participants' ages ranged from 5 to 86 years). The correlation between stage scores produced with the 2 systems was .88. Although standard issue scoring and hierarchical complexity scoring often awarded different scores up to Kohlberg's Moral Stage 2/3, from his Moral Stage 3 onward, scores awarded with the two systems predominantly agreed. The author explores the implications for developmental research.

Investigation of the timesaver process for de-burring and cleaning the plate for the Atlas Tilecalorimeter

International Nuclear Information System (INIS)

Guarino, V.; Kocenko, L.; Wood, K.

1997-01-01

The Timesaver belt grinding machine has been selected by the Atlas collaboration for deburring the master and spacer plates after die stamping and laser cutting, respectively. However, the question has been raised as to whether or not the plates are sufficiently clean after going through the Timesaver machine to immediately be glued into a submodule assembly. This would greatly enhance the production of submodules because the task of cleaning individual master and spacer plates is labor intensive and time consuming as well as raises environmental issues with the detergent that is used. In order to investigate the possibility of using the Timesaver process to clean the plates as well as debur them, several plates were run through the machine and their cleanliness inspected before and after. In addition, several glue samples were subjected to the same process, glued, and then pulled apart in an attempt to gauge the cleanliness of the plates. From this series of tests it can be concluded that the wet Timesaver machine can adequately prepare the surface of the master and spacer plates as well as clean the plates for gluing. The machine was able to adequately remove all of the oil and grime from the test plates. Also, from the single test on the dry machine it appears that significant cleaning will be required to adequately clean the plates before gluing in order to remove the remaining grit

Experimental and numerical studies on two-stage combustion of biomass

Energy Technology Data Exchange (ETDEWEB)

Houshfar, Eshan

2012-07-01

In this thesis, two-stage combustion of biomass was experimentally/numerically investigated in a multifuel reactor. The following emissions issues have been the main focus of the work: 1- NOx and N2O 2- Unburnt species (CO and CxHy) 3- Corrosion related emissions.The study had a focus on two-stage combustion in order to reduce pollutant emissions (primarily NOx emissions). It is well known that pollutant emissions are very dependent on the process conditions such as temperature, reactant concentrations and residence times. On the other hand, emissions are also dependent on the fuel properties (moisture content, volatiles, alkali content, etc.). A detailed study of the important parameters with suitable biomass fuels in order to optimize the various process conditions was performed. Different experimental studies were carried out on biomass fuels in order to study the effect of fuel properties and combustion parameters on pollutant emissions. Process conditions typical for biomass combustion processes were studied. Advanced experimental equipment was used in these studies. The experiments showed the effects of staged air combustion, compared to non-staged combustion, on the emission levels clearly. A NOx reduction of up to 85% was reached with staged air combustion using demolition wood as fuel. An optimum primary excess air ratio of 0.8-0.95 was found as a minimizing parameter for the NOx emissions for staged air combustion. Air staging had, however, a negative effect on N2O emissions. Even though the trends showed a very small reduction in the NOx level as temperature increased for non-staged combustion, the effect of temperature was not significant for NOx and CxHy, neither in staged air combustion or non-staged combustion, while it had a great influence on the N2O and CO emissions, with decreasing levels with increasing temperature. Furthermore, flue gas recirculation (FGR) was used in combination with staged combustion to obtain an enhanced NOx reduction. The

A study of the process of two staged anaerobic fermentation as a possible method for purifying sewage

Energy Technology Data Exchange (ETDEWEB)

Inoue, Y; Kouama, K; Matsuo, T

1983-01-01

Great attention has recently been given to the study of the processes of anaerobic fermentation, which may become alternatives to the existing methods for purifying waste waters which use aerobic microorganisms. A series of experimentswere conducted with the use of an artificially prepared liquid (fermented milk and starch) which imitates the waste to be purified, in order to explain the capabilities of the process of two staged anaerobic fermentation (DAS) as a method for purifying waste waters. The industrial system of the process includes: a fermentation vat for acetic fermentation with recirculation of the sediment, a primary settler, a fermentation tank for methane fermentation and a secondary settler. The process was conducted at a loading speed (based on Carbon) from 0.15 to 0.4 kilograms per cubic meter per day at a temperature of 38C. The degree of conversion of the fermented organic substances into volatile organic acids was not a function of the loading speed and was 54 to 57 percent in the acetic fermentation tank, where 95 to 97 percent of the organic material was broken down with the production of methane and carbon dioxide.

A Novel Process for Joining Ti Alloy and Al Alloy using Two-Stage Sintering Powder Metallurgy

Science.gov (United States)

Long, Luping; Liu, Wensheng; Ma, Yunzhu; Wu, Lei; Liu, Chao

2018-04-01

The major challenges for conventional diffusion bonding of joining Ti alloy and Al alloy are the undesirable interfacial reaction, low matrixes and joint strength. To avoid the problem in diffusion bonding, a novel two-stage sintering powder metallurgy process is developed. In the present work, the interface characterization and joint performance of the bonds obtained by powder metallurgy bonding are investigated and are compared with the diffusion bonded Ti/Al joints obtained with the same and the optimized process parameters. The results show that no intermetallic compound is visible in the Ti/Al joint obtained by powder metallurgy bonding, while a new layer formed at the joint diffusion bonded with the same parameters. The maximum tensile strength of joint obtained by diffusion bonding is 58 MPa, while a higher tensile strength reaching 111 MPa for a bond made by powder metallurgy bonding. Brittle fractures occur at all the bonds. It is shown that the powder metallurgy bonding of Ti/Al is better than diffusion bonding. The results of this study should benefit the bonding quality.

Acrylic vessel cleaning tests

International Nuclear Information System (INIS)

Earle, D.; Hahn, R.L.; Boger, J.; Bonvin, E.

1997-01-01

The acrylic vessel as constructed is dirty. The dirt includes blue tape, Al tape, grease pencil, gemak, the glue or residue form these tapes, finger prints and dust of an unknown composition but probably mostly acrylic dust. This dirt has to be removed and once removed, the vessel has to be kept clean or at least to be easily cleanable at some future stage when access becomes much more difficult. The authors report on the results of a series of tests designed: (a) to prepare typical dirty samples of acrylic; (b) to remove dirt stuck to the acrylic surface; and (c) to measure the optical quality and Th concentration after cleaning. Specifications of the vessel call for very low levels of Th which could come from tape residues, the grease pencil, or other sources of dirt. This report does not address the concerns of how to keep the vessel clean after an initial cleaning and during the removal of the scaffolding. Alconox is recommended as the cleaner of choice. This acrylic vessel will be used in the Sudbury Neutrino Observatory

Optimization of the process of steel strip perforation and nickel platting for the purpose of elimination of trichloroethylene from the cleaning process of perforated steel strip

Directory of Open Access Journals (Sweden)

Petrović Aleksandra B.

2009-01-01

Full Text Available In the production of pocket type electrodes for Ni-Cd batteries perforation of proper steel strips and then nickel platting of perforated steel strips were made. In the nickel platting process, the organic solvent, trichloroethylene, has previously been used for cleaning. Due to the carcinogenic nature of trichloroethylene and the many operations previously required during cleaning, it was considered to do cleaning of perforated steel strips without use of the mentioned organic solvent. In the purpose of elimination of trichloroethylene from the cleaning process of perforated steel strips, the tests of perforation of steel strips with use of oils of different viscosity were made. It was shown that there was no dysfunction during the work of the perforation plants, meaning there was no additional heating of the strips, deterring of the steel filings, nor excessive wearing of the perforation apparatus. The perforation percent was the same irrelevant of the viscosity of the used oil. Before being perforated using the oils with different viscosity, the nickel platting steel strips were cleaned in different degreasers (based on NaOH as well as on KOH. It was shown that efficient cleaning without the use of trichloroethylene is possible with the use of oil with smaller viscosity in the perforated steel strips process and the degreaser based on KOH in the cleaning process, before nickel platting. It also appeared that the alkali degreaser based on KOH was more efficient, bath corrections were made less often and the working period of the baths was longer, which all in summary means less quantity of chemicals needed for degreasing of perforated steel strips.

Comparison of Oone-Stage Free Gracilis Muscle Flap With Two-Stage Method in Chronic Facial Palsy

Directory of Open Access Journals (Sweden)

J Ghaffari

2007-08-01

Full Text Available Background:Rehabilitation of facial paralysis is one of the greatest challenges faced by reconstructive surgeons today. The traditional method for treatment of patients with facial palsy is the two-stage free gracilis flap which has a long latency period of between the two stages of surgery.Methods: In this paper, we prospectively compared the results of the one-stage gracilis flap method with the two -stage technique.Results:Out of 41 patients with facial palsy refered to Hazrat-e-Fatemeh Hospital 31 were selected from whom 22 underwent two- stage and 9 one-stage method treatment. The two groups were identical according to age,sex,intensity of illness, duration, and chronicity of illness. Mean duration of follow up was 37 months. There was no significant relation between the two groups regarding the symmetry of face in repose, smiling, whistling and nasolabial folds. Frequency of complications was equal in both groups. The postoperative surgeons and patients' satisfaction were equal in both groups. There was no significant difference between the mean excursion of muscle flap in one-stage (9.8 mm and two-stage groups (8.9 mm. The ratio of contraction of the affected side compared to the normal side was similar in both groups. The mean time of the initial contraction of the muscle flap in the one-stage group (5.5 months had a significant difference (P=0.001 with the two-stage one (6.5 months.The study revealed a highly significant difference (P=0.0001 between the mean waiting period from the first operation to the beginning of muscle contraction in one-stage(5.5 monthsand two-stage groups(17.1 months.Conclusion:It seems that the results and complication of the two methods are the same,but the one-stage method requires less time for facial reanimation,and is costeffective because it saves time and decreases hospitalization costs.

Remedial actions of nuclear safety shot sites: Double Tracks and Clean Slates

International Nuclear Information System (INIS)

Sanchez, M.; Shotton, M.; Lyons, C.

1998-03-01

Remedial actions of plutonium (Pu)-contaminated soils are in the preliminary stages of development at the Nevada Test Site (NTS). Interim clean-up actions were completed at the Double Tracks and Clean Slate 1 safety shot sites in 1996 and 1997, respectively. Soil at both sites, with a total transuranic activity greater than 20 picoCuries per gram (pCi/g), was excavated and shipped to the NTS for disposal. Characterization and assessment efforts were initiated at the Double Tracks site in 1995, and the clean-up of this site as an interim action was completed in 1996. Clean-up of this site consisted of taking site-specific data and applying rationale for dose and risk calculations in selecting parameter values for the interim corrective action level. The remediation process included excavating and stockpiling the contaminated soil and loading the soil into supersacks with approximately 1,513 cubic meters (53,500 cubic feet) being shipped to the NTS for disposal. In 1997, remediation began on the Clean Slate 1 site on which characterization had already been completed using a very similar approach; however, the site incorporated lessons learned, cost efficiencies, and significant improvements to the process. This paper focuses on those factors and the progress that has been made in cleaning up the sites. The application of a technically reasonable remediation method, as well as the cost factors that supported transport and disposal of the low-level waste in bulk are discussed

New stage of clean coal technology in Japan; Clean coal technology no aratana tenkai ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Kawaguchi, Y [Agency of Natural Resources and Energy, Tokyo (Japan)

1996-09-01

The paper described the positioning and new development of clean coal technology. Coal is an important resource which supplies approximately 30% of the energy consumed in all the world. In the Asian/Pacific region, especially, a share of coal in energy is high, around 60% of the world, and it is indispensable to continue using coal which is abundantly reserved. Japan continues using coal as an important energy among petroleum substituting energies taking consideration of the global environment, and is making efforts for development and promotion of clean coal technology aiming at further reduction of environmental loads. Moreover, in the Asian region where petroleum depends greatly upon outside the region, it is extremely important for stabilization of Japan`s energy supply that coal producing countries in the region promote development/utilization of their coal resources. For this, it is a requirement for Japan to further a coal policy having an outlook of securing stable coal supply/demand in the Asian region. 6 figs., 2 tabs.

Two-Stage Load Shedding for Secondary Control in Hierarchical Operation of Islanded Microgrids

DEFF Research Database (Denmark)

Zhou, Quan; Li, Zhiyi; Wu, Qiuwei

2018-01-01

A two-stage load shedding scheme is presented to cope with the severe power deficit caused by microgrid islanding. Coordinated with the fast response of inverter-based distributed energy resources (DERs), load shedding at each stage and the resulting power flow redistribution are estimated....... The first stage of load shedding will cease rapid frequency decline in which the measured frequency deviation is employed to guide the load shedding level and process. Once a new steady-state is reached, the second stage is activated, which performs load shedding according to the priorities of loads...

Attainability and minimum energy of single-stage membrane and membrane/distillation hybrid processes

KAUST Repository

Alshehri, Ali

2014-12-01

As an energy-efficient separation method, membrane technology has attracted more and more attentions in many challenging separation processes. The attainability and the energy consumption of a membrane process are the two basic fundamental questions that need to be answered. This report aims to use process simulations to find: (1) at what conditions a single-stage membrane process can meet the separation task that is defined by product purity and recovery ratio and (2) what are the most important parameters that determine the energy consumption. To perform a certain separation task, it was found that both membrane selectivity and pressure ratio exhibit a minimum value that is defined only by product purity and recovery ratio. The membrane/distillation hybrid system was used to study the energy consumption. A shortcut method was developed to calculate the minimum practical separation energy (MPSE) of the membrane process and the distillation process. It was found that the MPSE of the hybrid system is only determined by the membrane selectivity and the applied transmembrane pressure ratio in three stages. At the first stage when selectivity is low, the membrane process is not competitive to the distillation process. Adding a membrane unit to a distillation tower will not help in reducing energy. At the second medium selectivity stage, the membrane/distillation hybrid system can help reduce the energy consumption, and the higher the membrane selectivity, the lower is the energy. The energy conservation is further improved as pressure ratio increases. At the third stage when both selectivity and pressure ratio are high, the hybrid system will change to a single-stage membrane unit and this change will cause significant reduction in energy consumption. The energy at this stage keeps decreasing with selectivity at slow rate, but slightly increases with pressure ratio. Overall, the higher the membrane selectivity, the more the energy is saved. Therefore, the two

Rapid formation of phase-clean 110 K (Bi-2223) powders derived via freeze-drying process

Science.gov (United States)

Balachandran, U.

1996-06-04

A process for the preparation of amorphous precursor powders for Pb-doped Bi{sub 2}Sr{sub 2} Ca{sub 2}Cu{sub 3}O{sub x} (2223) includes a freeze-drying process incorporating a splat-freezing step. The process generally includes splat freezing a nitrate solution of Bi, Pb, Sr, Ca, and Cu to form flakes of the solution without any phase separation; grinding the frozen flakes to form a powder; freeze-drying the frozen powder; heating the dried powder to form a dry green precursor powders; denitrating the green-powders; heating the denitrated powders to form phase-clean Bi-2223 powders. The grain boundaries of the 2223 grains appear to be clean, leading to good intergrain contact between 2223 grains. 11 figs.

Dry Phosphorus silicate glass etching and surface conditioning and cleaning for multi-crystalline silicon solar cell processing

International Nuclear Information System (INIS)

Kagilik, Ahmed S.

2014-01-01

As an alternative to the wet chemical etching method, dry chemical etching processes for Phosphorus silicate glass [PSG} layer removal using Trifluormethane/Sulfur Hexafluoride (CHF 3 / SF 6 ) gas mixture in commercial silicon-nitride plasma enhanced chemical vapour deposition (SiN-PECVD) system is applied. The dependence of the solar cell performance on the etching temperature is investigated and optimized. It is found that the SiN-PECVD system temperature variation has a significant impact on the whole solar cell characteristics. A dry plasma cleaning treatment of the Si wafer surface after the PSG removal step is also investigated and developed. The cleaning step is used to remove the polymer film which is formed during the PSG etching using both oxygen and hydrogen gases. By applying an additional cleaning step, the polymer film deposited on the silicon wafer surface after PSG etching is eliminated. The effect of different plasma cleaning conditions on solar cell performance is investigated. After optimization of the plasma operating conditions, the performance of the solar cell is improved and the overall gain in efficiency of 0.6% absolute is yielded compared to a cell without any further cleaning step. On the other hand, the best solar cell characteristics can reach values close to that achieved by the conventional wet chemical etching processes demonstrating the effectiveness of the additional O 2 /H 2 post cleaning treatment.(author)

Performance study of a heat pump driven and hollow fiber membrane-based two-stage liquid desiccant air dehumidification system

International Nuclear Information System (INIS)

Zhang, Ning; Yin, Shao-You; Zhang, Li-Zhi

2016-01-01

Graphical abstract: A heat pump driven, hollow fiber membrane-based two-stage liquid desiccant air dehumidification system. - Highlights: • A two-stage hollow fiber membrane based air dehumidification is proposed. • It is heat pump driven liquid desiccant system. • Performance is improved 20% upon single stage system. • The optimal first to second stage dehumidification area ratio is 1.4. - Abstract: A novel compression heat pump driven and hollow fiber membrane-based two-stage liquid desiccant air dehumidification system is presented. The liquid desiccant droplets are prevented from crossing over into the process air by the semi-permeable membranes. The isoenthalpic processes are changed to quasi-isothermal processes by the two-stage dehumidification processes. The system is set up and a model is proposed for simulation. Heat and mass capacities in the system, including the membrane modules, the condenser, the evaporator and the heat exchangers are modeled in detail. The model is also validated experimentally. Compared with a single-stage dehumidification system, the two-stage system has a lower solution concentration exiting from the dehumidifier and a lower condensing temperature. Thus, a better thermodynamic system performance is realized and the COP can be increased by about 20% under the typical hot and humid conditions in Southern China. The allocations of heat and mass transfer areas in the system are also investigated. It is found that the optimal regeneration to dehumidification area ratio is 1.33. The optimal first to second stage dehumidification area ratio is 1.4; and the optimal first to second stage regeneration area ratio is 1.286.

Stuart oil shale project stage two: executive summary: draft environmental impact statement

International Nuclear Information System (INIS)

1999-09-01

The project is an oil shale open pit mine and processing operation that is currently being commissioned 15 km north of Gladstone, Queensland, Australia, and is owned as a joint venture by Southern Pacific Petroleum N.L., Central Pacific Minerals N.L, and Suncor Energy Inc., a leading Canadian company that is an integrated energy company. The results of a comprehensive investigation are included of the potential environmental impacts of the project, and which are described in the Draft Environmental Impact Statement (EIS). In stage two, there is included the existing mine expansion as well as the construction of an additional process plant based around a larger commercial scale ATP oil shale processing plant. The new stage two operation will be developed next to and integral with services and infrastructure provided for stage one. Described are: the assessment process, regulatory framework and the project area, the needs for an alternative to the project, the proposal itself, the existing natural, social and economic impacts, and the environmental impacts as well as plans for their mitigation. In appendices there are included a draft environmental management overview strategy and an environmental management plan. The elements covered in the report by section are: background, need for the project, the proponent, legislation and approvals, project description, environmental issues and impact management

One-stage versus two-stage exchange arthroplasty for infected total knee arthroplasty: a systematic review.

Science.gov (United States)

Nagra, Navraj S; Hamilton, Thomas W; Ganatra, Sameer; Murray, David W; Pandit, Hemant

2016-10-01

Infection complicating total knee arthroplasty (TKA) has serious implications. Traditionally the debate on whether one- or two-stage exchange arthroplasty is the optimum management of infected TKA has favoured two-stage procedures; however, a paradigm shift in opinion is emerging. This study aimed to establish whether current evidence supports one-stage revision for managing infected TKA based on reinfection rates and functional outcomes post-surgery. MEDLINE/PubMed and CENTRAL databases were reviewed for studies that compared one- and two-stage exchange arthroplasty TKA in more than ten patients with a minimum 2-year follow-up. From an initial sample of 796, five cohort studies with a total of 231 patients (46 single-stage/185 two-stage; median patient age 66 years, range 61-71 years) met inclusion criteria. Overall, there were no significant differences in risk of reinfection following one- or two-stage exchange arthroplasty (OR -0.06, 95 % confidence interval -0.13, 0.01). Subgroup analysis revealed that in studies published since 2000, one-stage procedures have a significantly lower reinfection rate. One study investigated functional outcomes and reported that one-stage surgery was associated with superior functional outcomes. Scarcity of data, inconsistent study designs, surgical technique and antibiotic regime disparities limit recommendations that can be made. Recent studies suggest one-stage exchange arthroplasty may provide superior outcomes, including lower reinfection rates and superior function, in select patients. Clinically, for some patients, one-stage exchange arthroplasty may represent optimum treatment; however, patient selection criteria and key components of surgical and post-operative anti-microbial management remain to be defined. III.

Operating Characteristics of a Continuous Two-Stage Bubbling Fluidized-Bed Process

International Nuclear Information System (INIS)

Youn, Pil-Sang; Choi, Jeong-Hoo

2014-01-01

Flow characteristics and the operating range of gas velocity was investigated for a two-stage bubbling fluidized-bed (0.1 m-i.d., 1.2 m-high) that had continuous solids feed and discharge. Solids were fed in to the upper fluidized-bed and overflowed into the bed section of the lower fluidized-bed through a standpipe (0.025 m-i.d.). The standpipe was simply a dense solids bed with no mechanical or non-mechanical valves. The solids overflowed the lower bed for discharge. The fluidizing gas was fed to the lower fluidized-bed and the exit gas was also used to fluidize the upper bed. Air was used as fluidizing gas and mixture of coarse (<1000 μm in diameter and 3090 kg/m 3 in apparent density) and fine (<100 μm in diameter and 4400 kg/m 3 in apparent density) particles were used as bed materials. The proportion of fine particles was employed as the experimental variable. The gas velocity of the lower fluidized-bed was defined as collapse velocity in the condition that the standpipe was emptied by upflow gas bypassing from the lower fluidized-bed. It could be used as the maximum operating velocity of the present process. The collapse velocity decreased after an initial increase as the proportion of fine particles increased. The maximum took place at the proportion of fine particles 30%. The trend of the collapse velocity was similar with that of standpipe pressure drop. The collapse velocity was expressed as a function of bulk density of particles and voidage of static bed. It increased with an increase of bulk density, however, decreased with an increase of voidage of static bed

Deep cleaning of a metallurgical zinc leaching residue and recovery of valuable metals

Science.gov (United States)

Xing, Peng; Ma, Bao-zhong; Zeng, Peng; Wang, Cheng-yan; Wang, Ling; Zhang, Yong-lu; Chen, Yong-qiang; Wang, Shuo; Wang, Qiu-yin

2017-11-01

Huge quantities of zinc leaching residues (ZLRs) generated from zinc production are dumped continuously around the world and pose a potential environmental threat because of their considerable amounts of entrained heavy metals (mainly lead). Most ZLRs have not been properly treated and the valuable metals in them have not yet been effectively recovered. Herein, the deep cleaning of a ZLR and recovery of valuable metals via a hydrometallurgical route were investigated. The cleaning process consists of two essential stages: acid leaching followed by calcium chloride leaching. The optimum conditions for extracting zinc, copper, and indium by acid leaching were a sulfuric acid concentration of 200 g·L-1, a liquid/solid ratio of 4:1 (mL/g), a leaching time of 2 h, and a temperature of 90°C. For lead and silver extractions, the optimum conditions were a calcium chloride concentration of 400 g·L-1, a pH value of 1.0, a leaching time of 1 h, and a temperature of 30°C. After calcium chloride leaching, silver and lead were extracted out and the lead was finally recovered as electrolytic lead by electrowinning. The anglesite phase, which poses the greatest potential environmental hazard, was removed from the ZLR after deep cleaning, thus reducing the cost of environmental management of ZLRs. The treatment of chlorine and spent electrolyte generated in the process was discussed.

EBR-II experience with sodium cleaning and radioactivity decontamination

International Nuclear Information System (INIS)

Ruther, W.E.; Smith, C.R.F.

1978-01-01

The EBR-II is now in Its 13th year of operation. During that period more than 2400 subassemblies have been cleaned of sodium without a serious incident of any kind by a two-step process developed at Argonne. Sodium cleaning and decontamination of other reactor components has been performed only on the relatively few occasions in which a repair or replacement has been required. A summary of the EBR-II experience will be presented. A new facility will be described for the improved cleaning and maintenance of sodium-wetted primary components

EBR-II experience with sodium cleaning and radioactivity decontamination

Energy Technology Data Exchange (ETDEWEB)

Ruther, W E; Smith, C R.F. [Argonne National Laboratory, Argonne (United States)

1978-08-01

The EBR-II is now in Its 13th year of operation. During that period more than 2400 subassemblies have been cleaned of sodium without a serious incident of any kind by a two-step process developed at Argonne. Sodium cleaning and decontamination of other reactor components has been performed only on the relatively few occasions in which a repair or replacement has been required. A summary of the EBR-II experience will be presented. A new facility will be described for the improved cleaning and maintenance of sodium-wetted primary components.

Staging of gastric adenocarcinoma using two-phase spiral CT: correlation with pathologic staging

International Nuclear Information System (INIS)

Seo, Tae Seok; Lee, Dong Ho; Ko, Young Tae; Lim, Joo Won

1998-01-01

To correlate the preoperative staging of gastric adenocarcinoma using two-phase spiral CT with pathologic staging. One hundred and eighty patients with gastric cancers confirmed during surgery underwent two-phase spiral CT, and were evaluated retrospectively. CT scans were obtained in the prone position after ingestion of water. Scans were performed 35 and 80 seconds after the start of infusion of 120mL of non-ionic contrast material with the speed of 3mL/sec. Five mm collimation, 7mm/sec table feed and 5mm reconstruction interval were used. T-and N-stage were determined using spiral CT images, without knowledge of the pathologic results. Pathologic staging was later compared with CT staging. Pathologic T-stage was T1 in 70 cases(38.9%), T2 in 33(18.3%), T3 in 73(40.6%), and T4 in 4(2.2%). Type-I or IIa elevated lesions accouted for 10 of 70 T1 cases(14.3%) and flat or depressed lesions(type IIb, IIc, or III) for 60(85.7%). Pathologic N-stage was NO in 85 cases(47.2%), N1 in 42(23.3%), N2 in 31(17.2%), and N3 in 22(12,2%). The detection rate of early gastric cancer using two-phase spiral CT was 100.0%(10 of 10 cases) among elevated lesions and 78.3%(47 of 60 cases) among flat or depressed lesions. With regard to T-stage, there was good correlation between CT image and pathology in 86 of 180 cases(47.8%). Overstaging occurred in 23.3%(42 of 180 cases) and understaging in 28.9%(52 of 180 cases). With regard to N-stage, good correlation between CT image and pathology was noted in 94 of 180 cases(52.2%). The rate of understaging(31.7%, 57 of 180 cases) was higher than that of overstaging(16.1%, 29 of 180 cases)(p<0.001). The detection rate of early gastric cancer using two-phase spiral CT was 81.4%, and there was no significant difference in detectability between elevated and depressed lesions. Two-phase spiral CT for determing the T-and N-stage of gastric cancer was not effective;it was accurate in abont 50% of cases understaging tended to occur.=20

Production of poly(hydroxybutyrate-hydroxyvalerate) from waste organics by the two-stage process: focus on the intermediate volatile fatty acids.

Science.gov (United States)

Shen, Liang; Hu, Hongyou; Ji, Hongfang; Cai, Jiyuan; He, Ning; Li, Qingbiao; Wang, Yuanpeng

2014-08-01

The two-stage process, coupling volatile fatty acids (VFAs) fermentation and poly(hydroxybutyrate-hydroxyvalerate) (P(HB/HV)) biosynthesis, was investigated for five waste organic materials. The overall conversion efficiencies were glycerol>starch>molasses>waste sludge>protein, meanwhile the maximum P(HB/HV) (1.674 g/L) was obtained from waste starch. Altering the waste type brought more effects on VFAs composition other than the yield in the first stage, which in turn greatly changed the yield in the second stage. Further study showed that even-number carbon VFAs (or odd-number ones) had a good positive linear relationship with P(HB/HV) content of HB (or HV). Additionally, VFA producing microbiota was analyzed by pyrosequencing methods for five wastes, which indicated that specific species (e.g., Lactobacillus for protein; Ethanoligenens for starch; Ruminococcus and Limnobacter for glycerol) were dominant in the community for VFAs production. Potential competition among acidogenic bacteria specially involved to produce some VFA was proposed as well. Copyright © 2014 Elsevier Ltd. All rights reserved.

Private Exploration Primitives for Data Cleaning

OpenAIRE

Ge, Chang; Ilyas, Ihab F.; He, Xi; Machanavajjhala, Ashwin

2017-01-01

Data cleaning, or the process of detecting and repairing inaccurate or corrupt records in the data, is inherently human-driven. State of the art systems assume cleaning experts can access the data (or a sample of it) to tune the cleaning process. However, in many cases, privacy constraints disallow unfettered access to the data. To address this challenge, we observe and provide empirical evidence that data cleaning can be achieved without access to the sensitive data, but with access to a (no...

Frequency analysis of a two-stage planetary gearbox using two different methodologies

Science.gov (United States)

Feki, Nabih; Karray, Maha; Khabou, Mohamed Tawfik; Chaari, Fakher; Haddar, Mohamed

2017-12-01

This paper is focused on the characterization of the frequency content of vibration signals issued from a two-stage planetary gearbox. To achieve this goal, two different methodologies are adopted: the lumped-parameter modeling approach and the phenomenological modeling approach. The two methodologies aim to describe the complex vibrations generated by a two-stage planetary gearbox. The phenomenological model describes directly the vibrations as measured by a sensor fixed outside the fixed ring gear with respect to an inertial reference frame, while results from a lumped-parameter model are referenced with respect to a rotating frame and then transferred into an inertial reference frame. Two different case studies of the two-stage planetary gear are adopted to describe the vibration and the corresponding spectra using both models. Each case presents a specific geometry and a specific spectral structure.

Is dry cleaning all wet?

International Nuclear Information System (INIS)

Ryan, M.

1993-01-01

Chemical solvents from dry cleaning, particularly perchloroethylene (perc), have contributed to groundwater contamination, significant levels of air pollution in and around cleaners, and chemical accumulation in food. Questions are being raised about the process of cleaning clothes with chemical, and other less toxic cleaning methods are being explored. The EPA has focused attention on the 50 year old Friedburg method of cleaning, Ecoclean, which uses no dangerous chemicals and achieves comparable results. Unfortunately, the cleaning industry is resistant to change, so cutting back on amount of clothes that need dry cleaning and making sure labels aren't exaggerating when they say dry clean only, is frequently the only consumer option now

WINDOW-CLEANING

CERN Multimedia

Environmental Section / ST-TFM

2001-01-01

The two-month window-cleaning session on the Meyrin, Prévessin and LEP sites will soon begin. The cleaning contractors will work from Monday to Saturday, every week from 4.00 a.m. to 8.00 p.m. The work will be organised so as to disturb users as little as possible. In any event, a work notice will be left in each office 24 hours beforehand. To prevent any damage to documents or items which could occur despite the precautions taken, please clear completely the window-sills and the area immediately around them. If, however, for valid reasons, the work cannot be done on the scheduled day, please inform the Environmental Section by telephoning: 73753 / 74233 / 72242 If you are going to be absent during this two-month period, we should be grateful if you would clear the above mentioned areas before your departure. REMINDER To allow more thorough cleaning of the entrance doors to buildings and also facilitate the weekly work of the cleaning contractors, we ask you to make use of the notice boards at the...

Canyon solvent cleaning

International Nuclear Information System (INIS)

Reif, D.J.

1986-01-01

The HM Process at the Savannah River Plant (SRP) uses 7.5% tributylphosphate in n-paraffin as an extraction solvent. During use, the solvent is altered due to hydrolysis and radiolysis, forming materials that influence product losses, produce decontamination, and separation efficiencies. Laboratory studies to improve online solvent cleaning have shown the carbonate washing, although removing residual solvent activity does not remove binding ligands that hold fission products in the solvent. Treatment of solvent by an alumina adsorption process removes binding ligands and significantly improves recycle solvent performance. Both laboratory work defining a full-scale alumina adsorption process and the use of the process to clean HM Process first cycle solvent are presented

Surface properties and self-cleaning ability of the fluorinated acrylate coatings modified with dodecafluoroheptyl methacrylate through two adding ways

International Nuclear Information System (INIS)

Yang, Xin; Zhu, Liqun; Zhang, Yang; Chen, Yichi; Bao, Baiqing; Xu, Jinlong; Zhou, Weiwei

2014-01-01

Highlights: • A self-cleaning test is used to evaluate the self-cleaning ability of coatings. • Adding way of fluorine monomer has an influence on the self-cleaning ability. • The fluorine content of coating surface increases by changing modification method. • High contact angles and low sliding angles are advantageous for self-cleaning. • The self-cleaning ability of coatings is analyzed after scrubbing. - Abstract: The fluorine-modified acrylate resin was synthesized by solution radical polymerization using dodecafluoroheptyl methacrylate (DFMA) and other acrylate monomers. The same weight of DFMA was added into the reaction through two different ways: (1) adding DFMA as bottom monomer (AFBM); (2) adding DFMA drop by drop (AFDD). The different coatings were prepared by blending the fluorine-modified acrylate resin with the curing agent. Compared with AFDD coating, the AFBM coating exhibited better self-cleaning ability which was confirmed by the self-cleaning test through measuring the specular gloss of coatings before contamination and after water droplets flushing. The fluorine content at the surface of AFBM coating increased from 15.1 at.% to 23.1 at.%, while the water contact angles increased by 8° and the sliding angles decreased obviously. Furthermore, the contact angles and self-cleaning ability of the coatings prepared with DFMA through two adding ways both decreased after scrubbing by wet cotton because of the decrease of the surface fluorine atom content. It could be concluded that high contact angles and low sliding angles were advantageous for coatings to obtain excellent self-cleaning ability

Surface properties and self-cleaning ability of the fluorinated acrylate coatings modified with dodecafluoroheptyl methacrylate through two adding ways

Energy Technology Data Exchange (ETDEWEB)

Yang, Xin [Key Laboratory of Aerospace Advanced Materials and Performance (Ministry of Education), School of Material Science and Engineering, Beihang University, Beijing 100191 (China); Zhu, Liqun, E-mail: zhulq@buaa.edu.cn [Key Laboratory of Aerospace Advanced Materials and Performance (Ministry of Education), School of Material Science and Engineering, Beihang University, Beijing 100191 (China); Zhang, Yang [Key Laboratory of Aerospace Advanced Materials and Performance (Ministry of Education), School of Material Science and Engineering, Beihang University, Beijing 100191 (China); Chen, Yichi [Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry and Environment, Beihang University, Beijing 100191 (China); Bao, Baiqing; Xu, Jinlong; Zhou, Weiwei [Jiangsu Baihe Coatings Co., Ltd, Changzhou 213136 (China)

2014-03-01

Highlights: • A self-cleaning test is used to evaluate the self-cleaning ability of coatings. • Adding way of fluorine monomer has an influence on the self-cleaning ability. • The fluorine content of coating surface increases by changing modification method. • High contact angles and low sliding angles are advantageous for self-cleaning. • The self-cleaning ability of coatings is analyzed after scrubbing. - Abstract: The fluorine-modified acrylate resin was synthesized by solution radical polymerization using dodecafluoroheptyl methacrylate (DFMA) and other acrylate monomers. The same weight of DFMA was added into the reaction through two different ways: (1) adding DFMA as bottom monomer (AFBM); (2) adding DFMA drop by drop (AFDD). The different coatings were prepared by blending the fluorine-modified acrylate resin with the curing agent. Compared with AFDD coating, the AFBM coating exhibited better self-cleaning ability which was confirmed by the self-cleaning test through measuring the specular gloss of coatings before contamination and after water droplets flushing. The fluorine content at the surface of AFBM coating increased from 15.1 at.% to 23.1 at.%, while the water contact angles increased by 8° and the sliding angles decreased obviously. Furthermore, the contact angles and self-cleaning ability of the coatings prepared with DFMA through two adding ways both decreased after scrubbing by wet cotton because of the decrease of the surface fluorine atom content. It could be concluded that high contact angles and low sliding angles were advantageous for coatings to obtain excellent self-cleaning ability.

Experimental studies of two-stage centrifugal dust concentrator

Science.gov (United States)

Vechkanova, M. V.; Fadin, Yu M.; Ovsyannikov, Yu G.

2018-03-01

The article presents data of experimental results of two-stage centrifugal dust concentrator, describes its design, and shows the development of a method of engineering calculation and laboratory investigations. For the experiments, the authors used quartz, ceramic dust and slag. Experimental dispersion analysis of dust particles was obtained by sedimentation method. To build a mathematical model of the process, dust collection was built using central composite rotatable design of the four factorial experiment. A sequence of experiments was conducted in accordance with the table of random numbers. Conclusion were made.

Efficient methods of piping cleaning

Directory of Open Access Journals (Sweden)

Orlov Vladimir Aleksandrovich

2014-01-01

Full Text Available The article contains the analysis of the efficient methods of piping cleaning of water supply and sanitation systems. Special attention is paid to the ice cleaning method, in course of which biological foil and various mineral and organic deposits are removed due to the ice crust buildup on the inner surface of water supply and drainage pipes. These impurities are responsible for the deterioration of the organoleptic properties of the transported drinking water or narrowing cross-section of drainage pipes. The co-authors emphasize that the use of ice compared to other methods of pipe cleaning has a number of advantages due to the relative simplicity and cheapness of the process, economical efficiency and lack of environmental risk. The equipment for performing ice cleaning is presented, its technological options, terms of cleansing operations, as well as the volumes of disposed pollution per unit length of the water supply and drainage pipelines. It is noted that ice cleaning requires careful planning in the process of cooking ice and in the process of its supply in the pipe. There are specific requirements to its quality. In particular, when you clean drinking water system the ice applied should be hygienically clean and meet sanitary requirements.In pilot projects, in particular, quantitative and qualitative analysis of sediments adsorbed by ice is conducted, as well as temperature and the duration of the process. The degree of pollution of the pipeline was estimated by the volume of the remote sediment on 1 km of pipeline. Cleaning pipelines using ice can be considered one of the methods of trenchless technologies, being a significant alternative to traditional methods of cleaning the pipes. The method can be applied in urban pipeline systems of drinking water supply for the diameters of 100—600 mm, and also to diversion collectors. In the world today 450 km of pipelines are subject to ice cleaning method.Ice cleaning method is simple

Two stage heterotrophy/photoinduction culture of Scenedesmus incrassatulus: potential for lutein production.

Science.gov (United States)

Flórez-Miranda, Liliana; Cañizares-Villanueva, Rosa Olivia; Melchy-Antonio, Orlando; Martínez-Jerónimo, Fernando; Flores-Ortíz, Cesar Mateo

2017-11-20

A biomass production process including two stages, heterotrophy/photoinduction (TSHP), was developed to improve biomass and lutein production by the green microalgae Scenedesmus incrassatulus. To determine the effects of different nitrogen sources (yeast extract and urea) and temperature in the heterotrophic stage, experiments using shake flask cultures with glucose as the carbon source were carried out. The highest biomass productivity and specific pigment concentrations were reached using urea+vitamins (U+V) at 30°C. The first stage of the TSHP process was done in a 6L bioreactor, and the inductions in a 3L airlift photobioreactor. At the end of the heterotrophic stage, S. incrassatulus achieved the maximal biomass concentration, increasing from 7.22gL -1 to 17.98gL -1 with an increase in initial glucose concentration from 10.6gL -1 to 30.3gL -1 . However, the higher initial glucose concentration resulted in a lower specific growth rate (μ) and lower cell yield (Y x/s ), possibly due to substrate inhibition. After 24h of photoinduction, lutein content in S. incrassatulus biomass was 7 times higher than that obtained at the end of heterotrophic cultivation, and the lutein productivity was 1.6 times higher compared with autotrophic culture of this microalga. Hence, the two-stage heterotrophy/photoinduction culture is an effective strategy for high cell density and lutein production in S. incrassatulus. Copyright © 2017. Published by Elsevier B.V.

Quantitative Evaluation of Contamination on Dental Zirconia Ceramic by Silicone Disclosing Agents after Different Cleaning Procedures

Directory of Open Access Journals (Sweden)

Sebastian Wille

2015-05-01

Full Text Available The aim of this study was to evaluate the effectiveness of cleaning procedures for air-abraded zirconia after contamination with two silicone disclosing agents. Air-abraded zirconia ceramic specimens (IPS e.max ZirCAD were contaminated with either GC Fit Checker white or GC Fit Checker II. Untreated zirconia specimens were used as control. Afterwards the surfaces were cleaned either with waterspray or ultrasonically in 99% isopropanol or using a newly developed cleaning paste (Ivoclean. After cleaning X-ray photoelectron spectroscopy (XPS was performed and the relative peak intensities of Zr, C and Si were used for a qualitative comparison of the residuals. There was no significant difference between the two different silicone disclosing agents. An additional cleaning step with isopropanol led to a significantly lower amount of residuals on the surface, but an additional cleaning process with Ivoclean did not reduce the amount of carbon residuals in comparison to the isopropanol cleaning. Just the silicone amount on the surface was reduced. None of the investigated cleaning processes removed all residuals from the contaminated surface. Standard cleaning processes do not remove all residuals of the silicone disclosing agent from the surface. This may lead to a failure of the resin-ceramic bonding.

Cleaning Process Versus Laser-Damage Threshold of Coated Optical Components

International Nuclear Information System (INIS)

Rigatti, A.L.

2005-01-01

The cleaning of optical surfaces is important in the manufacture of high-laser-damage-threshold coatings, which are a key component on peak-power laser systems such as OMEGA located at the Laboratory for Laser Energetics (LLE). Since cleaning adds time, labor, and ultimately cost to the final coated component, this experiment was designed to determine the impact of different cleaning protocols on the measured laser-damage performance

Dynamic change of surface microbiota with different environmental cleaning methods between two wards in a hospital.

Science.gov (United States)

Chen, Chang-Hua; Tu, Chi-Chao; Kuo, Han-Yueh; Zeng, Rong-Fong; Yu, Cheng-Sheng; Lu, Henry Horng-Shing; Liou, Ming-Li

2017-01-01

Terminal disinfection and daily cleaning have been performed in hospitals in Taiwan for many years to reduce the risks of healthcare-associated infections. However, the effectiveness of these cleaning approaches and dynamic changes of surface microbiota upon cleaning remain unclear. Here, we report the surface changes of bacterial communities with terminal disinfection and daily cleaning in a medical intensive care unit (MICU) and only terminal disinfection in a respiratory care center (RCC) using 16s ribosomal RNA (rRNA) metagenomics. A total of 36 samples, including 9 samples per sampling time, from each ward were analysed. The clinical isolates were recorded during the sampling time. A large amount of microbial diversity was detected, and human skin microbiota (HSM) was predominant in both wards. In addition, the colonization rate of the HSM in the MICU was higher than that in the RCC, especially for Moraxellaceae. A higher alpha-diversity (p = 0.005519) and a lower UniFrac distance was shown in the RCC due to the lack of daily cleaning. Moreover, a significantly higher abundance among Acinetobacter sp., Streptococcus sp. and Pseudomonas sp. was shown in the RCC compared to the MICU using the paired t test. We concluded that cleaning changes might contribute to the difference in diversity between two wards.

Histological evaluation of the cleaning effectiveness of two reciprocating single-file systems in severely curved root canals: Reciproc versus WaveOne.

Science.gov (United States)

Carvalho, Maira de Souza; Junior, Emílio Carlos Sponchiado; Bitencourt Garrido, Angela Delfina; Roberti Garcia, Lucas da Fonseca; Franco Marques, André Augusto

2015-01-01

The aim of this study was to evaluate the cleaning effectiveness achieved with two reciprocating single-file systems in severely curved root canals: Reciproc and WaveOne. Twenty-five mesial roots of mandibular molars were randomly separated into two groups, according to the instrumentation system used. The negative control group consisted of five specimens that were not instrumented. The mesial canals (buccal and lingual) in Reciproc Group were instrumented with file R25 and the WaveOne group with the Primary file. The samples were submitted to histological processing and analyzed under a digital microscope. The WaveOne group presented a larger amount of debris than the Reciproc Group, however, without statistically significant difference (P > 0.05). A larger amount of debris in the control group was observed, with statistically significant difference to Reciproc and WaveOne groups (P file instrumentation systems presented similar effectiveness for root canal cleaning.

Morphological analysis of three wound-cleaning processes on potentially contamined wounds in rats

Directory of Open Access Journals (Sweden)

d'Acampora Armando José

2006-01-01

Full Text Available PURPOSE: To evaluate the inflammatory response of potentially infected wounds treated with isotonic saline solution, chlorhexidine and PVP-I, seven days after surgery. METHODS: Thirty-two male rats were used, divided into 4 groups. All animals had their surgical wounds infected with a standard bacterial inoculum. Control group (A: animals had their surgical wounds sutured without any kind of cleaning. Saline solution group (B: animals had their wounds cleaned with saline solution. Chlorhexidine group (C: animals had their wounds cleaned with chlorhexidine. PVP-I group (D: animals had their wounds cleaned with PVP-I. Seven days after surgery, all the animals had their skin submitted to microscopic and macroscopic evaluation. RESULTS: Edema was found on all histological slices analyzed, as well as vascular proliferation and congestion. Groups A and D showed presence of mild neutrophilic infiltrate, and moderate lymphocytic and macrophage infiltrate. Group B showed severe neutrophilic, macrophage, and lymphocytic infiltrate. Group C showed moderate neutrophilic, macrophage, and lymphocytic infiltrate. CONCLUSION: Group D was the group which showed inflammatory infiltrate most similar to the group that was not submitted to treatment.

Two-Stage Fuzzy Portfolio Selection Problem with Transaction Costs

Directory of Open Access Journals (Sweden)

Yanju Chen

2015-01-01

Full Text Available This paper studies a two-period portfolio selection problem. The problem is formulated as a two-stage fuzzy portfolio selection model with transaction costs, in which the future returns of risky security are characterized by possibility distributions. The objective of the proposed model is to achieve the maximum utility in terms of the expected value and variance of the final wealth. Given the first-stage decision vector and a realization of fuzzy return, the optimal value expression of the second-stage programming problem is derived. As a result, the proposed two-stage model is equivalent to a single-stage model, and the analytical optimal solution of the two-stage model is obtained, which helps us to discuss the properties of the optimal solution. Finally, some numerical experiments are performed to demonstrate the new modeling idea and the effectiveness. The computational results provided by the proposed model show that the more risk-averse investor will invest more wealth in the risk-free security. They also show that the optimal invested amount in risky security increases as the risk-free return decreases and the optimal utility increases as the risk-free return increases, whereas the optimal utility increases as the transaction costs decrease. In most instances the utilities provided by the proposed two-stage model are larger than those provided by the single-stage model.

Wide-bandwidth bilateral control using two-stage actuator system

International Nuclear Information System (INIS)

Kokuryu, Saori; Izutsu, Masaki; Kamamichi, Norihiro; Ishikawa, Jun

2015-01-01

This paper proposes a two-stage actuator system that consists of a coarse actuator driven by a ball screw with an AC motor (the first stage) and a fine actuator driven by a voice coil motor (the second stage). The proposed two-stage actuator system is applied to make a wide-bandwidth bilateral control system without needing expensive high-performance actuators. In the proposed system, the first stage has a wide moving range with a narrow control bandwidth, and the second stage has a narrow moving range with a wide control bandwidth. By consolidating these two inexpensive actuators with different control bandwidths in a complementary manner, a wide bandwidth bilateral control system can be constructed based on a mechanical impedance control. To show the validity of the proposed method, a prototype of the two-stage actuator system has been developed and basic performance was evaluated by experiment. The experimental results showed that a light mechanical impedance with a mass of 10 g and a damping coefficient of 2.5 N/(m/s) that is an important factor to establish good transparency in bilateral control has been successfully achieved and also showed that a better force and position responses between a master and slave is achieved by using the proposed two-stage actuator system compared with a narrow bandwidth case using a single ball screw system. (author)

Runway Operations Planning: A Two-Stage Solution Methodology

Science.gov (United States)

Anagnostakis, Ioannis; Clarke, John-Paul

2003-01-01

The airport runway is a scarce resource that must be shared by different runway operations (arrivals, departures and runway crossings). Given the possible sequences of runway events, careful Runway Operations Planning (ROP) is required if runway utilization is to be maximized. Thus, Runway Operations Planning (ROP) is a critical component of airport operations planning in general and surface operations planning in particular. From the perspective of departures, ROP solutions are aircraft departure schedules developed by optimally allocating runway time for departures given the time required for arrivals and crossings. In addition to the obvious objective of maximizing throughput, other objectives, such as guaranteeing fairness and minimizing environmental impact, may be incorporated into the ROP solution subject to constraints introduced by Air Traffic Control (ATC) procedures. Generating optimal runway operations plans was approached in with a 'one-stage' optimization routine that considered all the desired objectives and constraints, and the characteristics of each aircraft (weight class, destination, Air Traffic Control (ATC) constraints) at the same time. Since, however, at any given point in time, there is less uncertainty in the predicted demand for departure resources in terms of weight class than in terms of specific aircraft, the ROP problem can be parsed into two stages. In the context of the Departure Planner (OP) research project, this paper introduces Runway Operations Planning (ROP) as part of the wider Surface Operations Optimization (SOO) and describes a proposed 'two stage' heuristic algorithm for solving the Runway Operations Planning (ROP) problem. Focus is specifically given on including runway crossings in the planning process of runway operations. In the first stage, sequences of departure class slots and runwy crossings slots are generated and ranked based on departure runway throughput under stochastic conditions. In the second stage, the

Ensuring clean air: Developing a clean air strategy for British Columbia

International Nuclear Information System (INIS)

1992-04-01

In 1992, a clean air strategy will be developed to incorporate views of British Columbians on ways to meet goals related to air quality. A discussion paper is presented to provide information to those interested in participation in developing this strategy. The paper gives information on air quality issues important to the province, including local air quality, urban smog, ozone layer depletion, and global climate change. The views and concerns expressed by stakeholders who attended the Clean Air Conference in 1991 are summarized. The process used to develop the clean air strategy is outlined and some outcomes to be anticipated from the strategy are suggested, including policies and priorities for action to ensure clean air. Air pollutants of concern are total reduced sulfur, mainly from pulp mills and gas processing plants; smoke from wood burning; sulfur dioxide from pulp mills and gas plants; hydrogen fluoride from aluminum smelting; ground-level ozone in urban areas; and acid rain. Elements of a clean air strategy include a smoke management policy, management strategies for greenhouse gases and ozone smog, ozone layer protection measures, regional air quality management plans, and long-term planning efforts in energy use, transportation modes, community design, and land use. 12 refs., 14 figs., 2 tabs

Two-stage dental implants inserted in a one-stage procedure : a prospective comparative clinical study

NARCIS (Netherlands)

Heijdenrijk, Kees

2002-01-01

The results of this study indicate that dental implants designed for a submerged implantation procedure can be used in a single-stage procedure and may be as predictable as one-stage implants. Although one-stage implant systems and two-stage.

A Novel Two-Stage Dynamic Spectrum Sharing Scheme in Cognitive Radio Networks

Institute of Scientific and Technical Information of China (English)

Guodong Zhang; Wei Heng; Tian Liang; Chao Meng; Jinming Hu

2016-01-01

In order to enhance the efficiency of spectrum utilization and reduce communication overhead in spectrum sharing process,we propose a two-stage dynamic spectrum sharing scheme in which cooperative and noncooperative modes are analyzed in both stages.In particular,the existence and the uniqueness of Nash Equilibrium (NE) strategies for noncooperative mode are proved.In addition,a distributed iterative algorithm is proposed to obtain the optimal solutions of the scheme.Simulation studies are carried out to show the performance comparison between two modes as well as the system revenue improvement of the proposed scheme compared with a conventional scheme without a virtual price control factor.

Experimental and kinetics studies of aromatic hydrogenation in a two-stage hydrotreating process using NiMo/Al{sub 2}O{sub 3} and NiW/Al{sub 2}O{sub 3} catalysts

Energy Technology Data Exchange (ETDEWEB)

Owusu-Boakye, A.; Dalai, A.K.; Ferdous, D. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Chemical Engineering, Catalysis and Chemical Reaction Engineering Laboratories; Adjaye, J. [Syncrude Canada Ltd., Edmonton, AB (Canada)

2006-10-15

The degree of hydrogenation of aromatics in light gas oil (LGO) feed from Athabasca bitumen was examined using a two-stage process. Experiments were conducted in a trickle-bed reactor using 2 catalysts, namely nickel molybdenum alumina (NiMo/Al{sub 2}O{sub 3}) in stage one and nickel tungsten alumina (NiW/Al{sub 2}O{sub 3}) in the second stage. NiMo/Al{sub 2}O{sub 3} was used in the first stage in order to remove nitrogen and sulphur containing heteroatoms. NiW/Al{sub 2}O{sub 3} was used in the second stage for saturation of the aromatic rings in the hydrocarbon species. The catalysts were used under a range of temperature and pressure condition. Temperature and liquid hourly space velocity ranged from 350 to 390 degrees C and 1.0 to 1.5 per hour, respectively. Pressure was kept constant at 11.0 MPa for all experiments. Reaction time results from the two-stage process were compared with those from a single-stage where hydrotreating was performed over NiMo/AL{sub 2}O{sub 3}. Product samples from different feedstocks were analyzed with respect to sulfur, nitrogen and aromatic content. Gasoline selectivity and kinetic parameters for hydrodesulphurization (HDS) or hydrodenitrogenation (HDN) reactions for the feed materials were also compared. The effect of hydrogen sulphide (H{sub 2}S) inhibition on aromatics hydrogenation (HDA) was also kinetically modelled using the Langmuir-Hinshelwood approach. Kinetic analysis of the single-stage hydrotreating process showed that HDA and HDS activities were slowed by the presence of hydrogen sulphide that is produced as a by-product of the HDS process. However, with inter-stage removal of hydrogen sulphide in the two-stage process, significant improvement of the HDA and HDS activities were noted. It was concluded that the experimental data was successfully predicted by the Langmuir-Hinshelwood kinetic models. 27 refs., 4 tabs., 8 figs.

Influence of capacity- and time-constrained intermediate storage in two-stage food production systems

DEFF Research Database (Denmark)

Akkerman, Renzo; van Donk, Dirk Pieter; Gaalman, Gerard

2007-01-01

In food processing, two-stage production systems with a batch processor in the first stage and packaging lines in the second stage are common and mostly separated by capacity- and time-constrained intermediate storage. This combination of constraints is common in practice, but the literature hardly...... of systems like this. Contrary to the common sense in operations management, the LPT rule is able to maximize the total production volume per day. Furthermore, we show that adding one tank has considerable effects. Finally, we conclude that the optimal setup frequency for batches in the first stage...... pays any attention to this. In this paper, we show how various capacity and time constraints influence the performance of a specific two-stage system. We study the effects of several basic scheduling and sequencing rules in the presence of these constraints in order to learn the characteristics...

AN ELECTROLYTIC CIP-CLEANING PROCESS FOR REMOVING IMPURITIES FROM THE INNER SURFACE OF A METALLIC CONTAINER

DEFF Research Database (Denmark)

2008-01-01

The invention relates to a novel electrolytic process for removing impurities from the inner surface of a metallic container. The process is particularly useful for cleaning process reactors used for culturing microorganisms, and storage tanks used for storing metabolites formed in the process...... reactor, as well as containers for dairy products....

Identifying optimal cleaning cycles for heat exchangers subject to fouling and ageing

International Nuclear Information System (INIS)

Pogiatzis, Thomas; Ishiyama, Edward M.; Paterson, William R.; Vassiliadis, Vassilios S.; Wilson, D. Ian

2012-01-01

Fouling of heat exchangers causes reduced heat transfer and other penalties. Regular cleaning represents one widely used fouling mitigation strategy, where the schedule of cleaning actions can be optimised to minimise the cost of fouling. This paper investigates, for the first time, the situation where there are two cleaning methods available so that the mode of cleaning has to be selected as well as the cleaning interval. Ageing is assumed to convert the initial deposit, labelled 'gel', into a harder and more conductive form, labelled 'coke', which cannot be removed by one of the cleaning methods. The second method can remove both the gel layer and the coke layer, but costs more and requires the unit to be off-line longer for cleaning. Experimental data demonstrating the effects of ageing are presented. The industrial application is the comparison of cleaning-in-place methods with off-line mechanical cleaning. A process model is constructed for an isolated counter-current heat exchanger subject to fouling, where ageing is described by a simple two-layer model. Solutions generated by an NLP-based approach prove to be superior to a simpler heuristic. A series of case studies demonstrate that combinations of chemical and mechanical cleaning can be superior to mechanical cleaning alone for certain combinations of parameters.

Optimising the refrigeration cycle with a two-stage centrifugal compressor and a flash intercooler

Energy Technology Data Exchange (ETDEWEB)

Roeyttae, Pekka; Turunen-Saaresti, Teemu; Honkatukia, Juha [Lappeenranta University of Technology, Laboratory of Energy and Environmental Technology, PO Box 20, 53851 Lappeenranta (Finland)

2009-09-15

The optimisation of a refrigeration process with a two-stage centrifugal compressor and flash intercooler is presented in this paper. The two-stage centrifugal compressor stages are on the same shaft and the electric motor is cooled with the refrigerant. The performance of the centrifugal compressor is evaluated based on semi-empirical specific-speed curves and the effect of the Reynolds number, surface roughness and tip clearance have also been taken into account. The thermodynamic and transport properties of the working fluids are modelled with a real-gas model. The condensing and evaporation temperatures, the temperature after the flash intercooler, and cooling power have been chosen as fixed values in the process. The aim is to gain a maximum coefficient of performance (COP). The method of optimisation, the operation of the compressor and flash intercooler, and the method for estimating the electric motor cooling are also discussed in the article. (author)

Mass-transfer in extraction and reextraction as a single-stage process

International Nuclear Information System (INIS)

Rodriguez del Cerro, M.; Trilleros, J.A.; Otero de la Gandara, J.L.

1987-01-01

The rate of mass transfer between water and naftenic acid and threebutilphosphate in kerosen are studied in the two possibilities to or from water. The two insoluble phases are brought in to intimate contact with dispersed phase droplets, in a single-stage process. The evolution of the equilibrium distribution of solute is taken in consideration. (author)

Evidence of two-stage melting of Wigner solids

Science.gov (United States)

Knighton, Talbot; Wu, Zhe; Huang, Jian; Serafin, Alessandro; Xia, J. S.; Pfeiffer, L. N.; West, K. W.

2018-02-01

Ultralow carrier concentrations of two-dimensional holes down to p =1 ×109cm-2 are realized. Remarkable insulating states are found below a critical density of pc=4 ×109cm-2 or rs≈40 . Sensitive dc V-I measurement as a function of temperature and electric field reveals a two-stage phase transition supporting the melting of a Wigner solid as a two-stage first-order transition.

Comparison of two-stage thermophilic (68 degrees C/55 degrees C) anaerobic digestion with one-stage thermophilic (55 degrees C) digestion of cattle manure

DEFF Research Database (Denmark)

Nielsen, H.B.; Mladenovska, Zuzana; Westermann, Peter

2004-01-01

A two-stage 68degreesC/55degreesC anaerobic degradation process for treatment of cattle manure was studied. In batch experiments, an increase of the specific methane yield, ranging from 24% to 56%, was obtained when cattle manure and its fractions (fibers and liquid) were pretreated at 68degrees......, was compared with a conventional single-stage reactor running at 55degreesC with 15-days HRT. When an organic loading of 3 g volatile solids (VS) per liter per day was applied, the two-stage setup had a 6% to 8% higher specific methane yield and a 9% more effective VS-removal than the conventional single......-stage reactor. The 68degreesC reactor generated 7% to 9% of the total amount of methane of the two-stage system and maintained a volatile fatty acids (VFA) concentration of 4.0 to 4.4 g acetate per liter. Population size and activity of aceticlastic methanogens, syntrophic bacteria, and hydrolytic...

Microbial water quality in clean water tanks following inspection and cleaning

DEFF Research Database (Denmark)

Christensen, Sarah Christine Boesgaard; Esbjørn, Anne; Mollerup, Finn

Increased bacterial counts are often registered in drinking water leaving clean water tanks after the tanks have been emptied, inspected and cleaned by flushing. To investigate the reason for the increased bacterial concentrations and consequently limit it, samples from two clean water tanks befo...... start-up of the tanks, which may indicate that a substantial part of the bacteria in the drinking water leaving the tanks originated from the sand filter. This was supported by 16S DNA analyses....

Determination of properties of clean coal technology post-process residue

Directory of Open Access Journals (Sweden)

Agnieszka Klupa

2016-01-01

Full Text Available This article presents the possibilities of using modern measuring devices to determine the properties of process residues (Polish acronym: UPP. UPP was taken from the combustion process from a power plant in Silesia. Determining the properties of UPP is the basis for making decisions about its practical application, for example, as a raw material to obtain useful products such as: pozzolan, cenosphere or zeolite, for which there is demand. The development of advanced technology and science has given rise to modern and precise research tools that contribute to the development of appropriate methods to assess the properties of post-process residue. For this study the following were used: scanning electron microscope with EDS microanalysis and an analyzer for particle size-, shape- and number- analysis. The study conducted confirms the effectiveness of SEM analysis to determine the properties of post-process residue from Clean Coal Technologies (CCT. The results obtained are an introduction to further research on the determination of properties of CCT post-process residue. Research to determine the properties of CCT post-process residue only began relatively recently.

One-stage and two-stage penile buccal mucosa urethroplasty

African Journals Online (AJOL)

G. Barbagli

2015-12-02

Dec 2, 2015 ... there also seems to be a trend of decreasing urethritis and an increase of instrumentation and catheter related strictures in these countries as well [4–6]. The repair of penile urethral strictures may require one- or two- stage urethroplasty [7–10]. Certainly, sexual function can be placed at risk by any surgery ...

Surface cleaning in thin film technology

International Nuclear Information System (INIS)

Mattox, D.M.

1978-01-01

A ''clean surface'' is one that contains no significant amounts of undesirable material. This paper discusses the types and origin of various contaminants. Since cleaning is often equated with adhesion, the mechanisms of adhesion to oxide, metal, and organic surfaces are reviewed and cleaning processes for these surfaces are outlined. Techniques for monitoring surface cleaning are presented, and the importance of storage of clean surfaces is discussed. An extensive bibliography is given. 4 figs., 89 references

Pickering Unit 1 chemical cleaning

International Nuclear Information System (INIS)

Smee, J.L.; Fiola, R.J.; Brennenstuhl, K.R.; Zerkee, D.D.; Daniel, C.M.

1995-01-01

The secondary sides of all 12 boilers at Pickering Unit 1 were chemically cleaned in 1994 by the team of Ontario Hydro, B and W International (Cambridge, Ontario) and B and W Nuclear Technologies (Lynchburg, Virginia). A multi-step EPRI/SGOG process was employed in a similar manner to previous clearings at Units 5 and 6 in 1992 and 1993, respectively. A major innovation with the Unit 1 cleaning was the incorporation of a crevice cleaning step, the first time this had been done on Ontario Hydro plants. In addition, six boilers were cleaned in parallel compared to three at a time in previous Pickering cleanings. This significantly reduced cleaning time. A total of 6,770 kg of sludge was removed through direct chemical dissolution. It consisted of 66% iron/nickel oxides and 28% copper metal. A total of 1,600,000 L (420,000 US gallons) of liquid waste was produced. It was processed through the spent solvent treatment facility located at the Bruce Nuclear Power Development site. Visual inspection performed after the cleaning indicated that the crevices between the boiler tubes and the tube support structure were completely clear of deposit and the general condition of the tubing and lattice bars appeared to be in 'as new' condition. (author)

Two-stage Lagrangian modeling of ignition processes in ignition quality tester and constant volume combustion chambers

KAUST Repository

Alfazazi, Adamu; Kuti, Olawole Abiola; Naser, Nimal; Chung, Suk-Ho; Sarathy, Mani

2016-01-01

The ignition characteristics of isooctane and n-heptane in an ignition quality tester (IQT) were simulated using a two-stage Lagrangian (TSL) model, which is a zero-dimensional (0-D) reactor network method. The TSL model was also used to simulate

Evaluation of Various Cleaning Methods to Remove Bacillus Spores from Spacecraft Hardware Materials

Science.gov (United States)

Venkateswaran, Kasthuri; Chung, Shirley; Allton, Judith; Kern, Roger

2004-09-01

A detailed study was made of the biological cleaning effectiveness, defined in terms of the ability to remove bacterial spores, of a number of methods used to clean hardware surfaces. Aluminum (Al 6061) and titanium (Ti 6Al-4V) were chosen for the study as they were deemed the two materials most likely to be used in spacecraft extraterrestrial sampler construction. Metal coupons (1 cm × 2.5 cm) were precleaned and inoculated with 5.8 × 103 cultivable Bacillus subtilis spores, which are commonly found on spacecraft surfaces and in the assembly environments. The inoculated coupons were subsequently cleaned using: (1) 70% isopropyl alcohol wipe; (2) water wipe; (3) multiple-solvent flight-hardware cleaning procedures used at the Jet Propulsion Laboratory (JPL); (4) Johnson Space Center-developed ultrapure water rinse; and (5) a commercial, semi-aqueous, multiple-solvent (SAMS) cleaning process. The biological cleaning effectiveness was measured by agar plate assay, sterility test (growing in liquid media), and epifluorescent microscopy. None of the cleaning protocols tested completely removed viable spores from the surface of the aluminum. In contrast, titanium was capable of being cleaned to sterility by two methods, the JPL standard and the commercial SAMS cleaning process. Further investigation showed that the passivation step employed in the JPL standard method is an effective surface sterilant on both metals but not compatible with aluminum. It is recommended that titanium (Ti 6Al-4V) be considered superior to aluminum (Al 6061) for use in spacecraft sampling hardware, both for its potential to be cleaned to sterilization and for its ability to withstand the most effective cleaning protocols.

Three Stages and Two Systems of Visual Processing

Science.gov (United States)

1989-01-01

as squaring do not, in and of themselves, imply second- order processing . For example, the Adelson and Bergen’s (1985) detector of directional motion...rectification, halfwave rectification is a second- order processing scheme. Figure 8. Stimuli for analyzing second- order processing . (a) An x,y,t representation of

High-yield production of vanillin from ferulic acid by a coenzyme-independent decarboxylase/oxygenase two-stage process.

Science.gov (United States)

Furuya, Toshiki; Miura, Misa; Kuroiwa, Mari; Kino, Kuniki

2015-05-25

Vanillin is one of the world's most important flavor and fragrance compounds in foods and cosmetics. Recently, we demonstrated that vanillin could be produced from ferulic acid via 4-vinylguaiacol in a coenzyme-independent manner using the decarboxylase Fdc and the oxygenase Cso2. In this study, we investigated a new two-pot bioprocess for vanillin production using the whole-cell catalyst of Escherichia coli expressing Fdc in the first stage and that of E. coli expressing Cso2 in the second stage. We first optimized the second-step Cso2 reaction from 4-vinylguaiacol to vanillin, a rate-determining step for the production of vanillin. Addition of FeCl2 to the cultivation medium enhanced the activity of the resulting E. coli cells expressing Cso2, an iron protein belonging to the carotenoid cleavage oxygenase family. Furthermore, a butyl acetate-water biphasic system was effective in improving the production of vanillin. Under the optimized conditions, we attempted to produce vanillin from ferulic acid by a two-pot bioprocess on a flask scale. In the first stage, E. coli cells expressing Fdc rapidly decarboxylated ferulic acid and completely converted 75 mM of this substrate to 4-vinylguaiacol within 2 h at pH 9.0. After the first-stage reaction, cells were removed from the reaction mixture by centrifugation, and the pH of the resulting supernatant was adjusted to 10.5, the optimal pH for Cso2. This solution was subjected to the second-stage reaction. In the second stage, E. coli cells expressing Cso2 efficiently oxidized 4-vinylguaiacol to vanillin. The concentration of vanillin reached 52 mM (7.8 g L(-1)) in 24 h, which is the highest level attained to date for the biotechnological production of vanillin using recombinant cells. Copyright © 2015 Elsevier B.V. All rights reserved.

Wastewater treatment and biodiesel production by Scenedesmus obliquus in a two-stage cultivation process.

Science.gov (United States)

Álvarez-Díaz, P D; Ruiz, J; Arbib, Z; Barragán, J; Garrido-Pérez, M C; Perales, J A

2015-04-01

The microalga Scenedesmus obliquus was cultured in two cultivation stages: (1) in batch with real wastewater; (2) maintaining the stationary phase with different conditions of CO2, light and salinity according to a factorial design in order to improve the lipid content. The presence of the three factors increased lipid content from 35.8% to 49% at the end of the second stage; CO2 presence presented the highest direct effect increasing lipid content followed by light presence and salt presence. The ω-3 fatty acids content increased with CO2 and light presence acting in isolation, nevertheless, when both factors acted together the interaction effect was negative. The ω-3 eicosapentaenoic acid content of the oil from S. obliquus slightly exceeded the 1% maximum to be used as biodiesel source (EU normative). Therefore, it is suggested the blend with other oils or the selective extraction of the ω-3 fatty acids from S. obliquus oil. Copyright © 2015 Elsevier Ltd. All rights reserved.

Divergent methylation pattern in adult stage between two forms of Tetranychus urticae (Acari: Tetranychidae).

Science.gov (United States)

Yang, Si-Xia; Guo, Chao; Zhao, Xiu-Ting; Sun, Jing-Tao; Hong, Xiao-Yue

2017-02-19

The two-spotted spider mite, Tetranychus urticae Koch has two forms: green form and red form. Understanding the molecular basis of how these two forms established without divergent genetic background is an intriguing area. As a well-known epigenetic process, DNA methylation has particularly important roles in gene regulation and developmental variation across diverse organisms that do not alter genetic background. Here, to investigate whether DNA methylation could be associated with different phenotypic consequences in the two forms of T. urticae, we surveyed the genome-wide cytosine methylation status and expression level of DNA methyltransferase 3 (Tudnmt3) throughout their entire life cycle. Methylation-sensitive amplification polymorphism (MSAP) analyses of 585 loci revealed variable methylation patterns in the different developmental stages. In particular, principal coordinates analysis (PCoA) indicates a significant epigenetic differentiation between female adults of the two forms. The gene expression of Tudnmt3 was detected in all examined developmental stages, which was significantly different in the adult stage of the two forms. Together, our results reveal the epigenetic distance between the two forms of T. urticae, suggesting that DNA methylation might be implicated in different developmental demands, and contribute to different phenotypes in the adult stage of these two forms. © 2017 Institute of Zoology, Chinese Academy of Sciences.

Navigation of autonomous vehicles for oil spill cleaning in dynamic and uncertain environments

Science.gov (United States)

Jin, Xin; Ray, Asok

2014-04-01

In the context of oil spill cleaning by autonomous vehicles in dynamic and uncertain environments, this paper presents a multi-resolution algorithm that seamlessly integrates the concepts of local navigation and global navigation based on the sensory information; the objective here is to enable adaptive decision making and online replanning of vehicle paths. The proposed algorithm provides a complete coverage of the search area for clean-up of the oil spills and does not suffer from the problem of having local minima, which is commonly encountered in potential-field-based methods. The efficacy of the algorithm is tested on a high-fidelity player/stage simulator for oil spill cleaning in a harbour, where the underlying oil weathering process is modelled as 2D random-walk particle tracking. A preliminary version of this paper was presented by X. Jin and A. Ray as 'Coverage Control of Autonomous Vehicles for Oil Spill Cleaning in Dynamic and Uncertain Environments', Proceedings of the American Control Conference, Washington, DC, June 2013, pp. 2600-2605.

Offgas system particulate cleaning test and evaluation for the process experimental pilot plant

International Nuclear Information System (INIS)

Ayers, A.L. Jr.; Gale, L.G.; Stermer, D.L.

1990-01-01

The process experimental pilot plant (PREPP) incinerates mixed solid waste. The exhaust gas is processed through a wet offgas cleaning system. Rapid loading of the exhaust filters has been a problem and an important contributing factor is the use of quench solution containing a relatively high concentration of dissolved solids. The dissolved solids are released as a submicron particulate when the quench solution evaporates. A series of tests were performed to better identify the nature of the problem and explore solutions to the problem involving modifications to the quench process

Offgas system particulate cleaning test and evaluation for the Process Experimental Pilot Plant

International Nuclear Information System (INIS)

Ayers, A.L. Jr.; Gale, L.G.; Stermer, D.L.

1990-01-01

The Process Experimental Pilot Plant (PREPP) incinerates mixed solid waste. The exhaust gas is processed through a wet offgas cleaning system. Rapid loading of the exhaust filters has been a problem and an important contributing factor is the use of a quench solution containing a relatively high concentration of dissolved solids. The dissolved solids are released as a submicron particulate when the quench solution evaporates. A series of tests were performed to better identify the nature of the problem and explore solutions to the problem involving modifications to the quench process. 2 refs., 7 figs

Information processing theory in the early design stages

DEFF Research Database (Denmark)

Cash, Philip; Kreye, Melanie

2014-01-01

suggestions for improvements and support. One theory that may be particularly applicable to the early design stages is Information Processing Theory (IPT) as it is linked to the design process with regard to the key concepts considered. IPT states that designers search for information if they perceive......, the new knowledge is shared between the design team to reduce ambiguity with regards to its meaning and to build a shared understanding – reducing perceived uncertainty. Thus, we propose that Information-Processing Theory is suitable to describe designer activity in the early design stages...... uncertainty with regard to the knowledge necessary to solve a design challenge. They then process this information and compare if the new knowledge they have gained covers the previous knowledge gap. In engineering design, uncertainty plays a key role, particularly in the early design stages which has been...

Fossil fuels. Commercializing clean coal technologies

International Nuclear Information System (INIS)

Fultz, Keith O.; Sprague, John W.; Kirk, Roy J.; Clark, Marcus R. Jr.; Greene, Richard M.; Buncher, Carole S.; Kleigleng, Robert G.; Imbrogno, Frank W.

1989-03-01

Coal, an abundant domestic energy source, provides 25 percent of the nation's energy needs, but its use contributes to various types of pollution, including acid rain. The Department of Energy (DOE) has a Clean Coal Technology (CCT) program whose goal is to expand the use of coal in an environmentally safe manner by contributing to the cost of projects demonstrating the commercial applications of emerging clean coal technologies. Concerned about the implementation of the CCT program, the Chairman, Subcommittee on Energy and Power, House Committee on Energy and Commerce, requested GAO to report on (1) DOE's process of negotiating cooperative agreements with project sponsors, (2) changes DOE has made to the program, (3) the status of funded projects, and (4) the interrelationship between acid rain control proposals and the potential commercialization of clean coal technologies. Under the CCT program, DOE funds up to 50 percent of the cost of financing projects that demonstrate commercial applications of emerging clean coal technologies. DOE has conducted two solicitations for demonstration project proposals and is planning a third solicitation by May 1989. The Congress has appropriated $400 million for the first solicitation, or round one of the program, $575 million for round two, and $575 million for round three, for a total of $1.55 billion. For the round-one solicitation, DOE received 51 proposals from project sponsors. As of December 31, 1988, DOE had funded nine projects and was in the process of negotiating cooperative financial assistance agreements with sponsors of four projects. In September 1988, DOE selected 16 round-two projects from 55 proposals submitted and began the process of negotiating cooperative agreements with the project sponsors. The Congress has debated the need to reduce acid rain-causing emissions associated with fossil fuel combustion. The 100th Congress considered but did not enact about 20 acid rain control bills. On February 9, 1989

Air-cleaning devices for vented filtered LMFBR containment

International Nuclear Information System (INIS)

Muhlestein, L.D.; Hilliard, R.K.

1982-07-01

An effort lasting several years is summarized which evaluated, developed and tested air cleaning devices for potential use in breeder reactor containment venting applications. State-of-technology evaluations were completed for both a hypothetical head release accident and a primary vessel melt-through accident. Commercially available systems or components were tested which included HEPA filters, sand and gravel beds, and aqueous scrubbers. Large-scale demonstration tests were completed and results are presented for two- and three-stage conventional aqueous scrubber systems; and for a newly developed passive, submerged gravel scrubber

Stage-dependent hierarchy of criteria in multiobjective multistage decision processes

Directory of Open Access Journals (Sweden)

Tadeusz Trzaskalik

2017-01-01

Full Text Available This paper will consider a multiobjective, multistage discrete dynamic process with a changeable, state-dependent hierarchy of stage criteria determined by the decision maker. The goal of this paper is to answer the question of how to control a multistage process while taking into account both the tendency to achieve multiobjective optimization of the entire process and the time-varying hierarchy of stage criteria. We consider in detail possible situations, where the hierarchy of stage criteria changes over time in individual stages and is stage dependent. We present an interactive proposal to solving the problem, where the decision maker actively participates in finding the final realization of the process. The algorithm proposed is illustrated using a numerical example.

Hot gas cleaning, a targeted project

Energy Technology Data Exchange (ETDEWEB)

Romey, I. [University of Essen, Essen (Germany)

1998-11-01

Advanced hot gas cleaning systems will play a key role in future integrated combined cycle technologies. IGCC demonstration plants in operation or under construction are at present equipped with conventional wet gas scrubbing and cleaning systems. Feasibility studies for those IGCC plants have shown that the total efficiency of the processes can be improved using hot gas cleaning systems. However, this technology has not been developed and tested at a technical scale. Six well-known European industrial companies and research centres jointly worked together since January 1996 on a Targeted Project `Hot Gas Cleaning` to investigate and develop new hot gas cleaning systems for advanced clean coal power generation processes. In addition project work on chemical analysis and modelling was carried out in universities in England and Germany. The latest main findings were presented at the workshop. The main project aims are summarised as follows: to increase efficiency of advanced power generation processes; to obtain a reduction of alkalis and environmental emissions e.g. SO{sub 2}, NO{sub x}, CO{sub 2} and dust; and to develop the design basis for future industrial plants based on long-term operation of laboratory, pilot and demo-plants. To cover a range of possible process routes for future hot gas cleaning systems the following research programme is under investigation: removal of trace elements by different commercial and self developed sorbents; gas separation by membranes; separation of gas turbine relevant pollutants by hot filter dust and; H{sub 2}S removal and gas dedusting at high temperatures. 13 figs.

A preventive maintenance policy based on dependent two-stage deterioration and external shocks

International Nuclear Information System (INIS)

Yang, Li; Ma, Xiaobing; Peng, Rui; Zhai, Qingqing; Zhao, Yu

2017-01-01

This paper proposes a preventive maintenance policy for a single-unit system whose failure has two competing and dependent causes, i.e., internal deterioration and sudden shocks. The internal failure process is divided into two stages, i.e. normal and defective. Shocks arrive according to a non-homogeneous Poisson process (NHPP), leading to the failure of the system immediately. The occurrence rate of a shock is affected by the state of the system. Both an age-based replacement and finite number of periodic inspections are schemed simultaneously to deal with the competing failures. The objective of this study is to determine the optimal preventive replacement interval, inspection interval and number of inspections such that the expected cost per unit time is minimized. A case study on oil pipeline maintenance is presented to illustrate the maintenance policy. - Highlights: • A maintenance model based on two-stage deterioration and sudden shocks is developed. • The impact of internal system state on external shock process is studied. • A new preventive maintenance strategy combining age-based replacements and periodic inspections is proposed. • Postponed replacement of a defective system is provided by restricting the number of inspections.

Evaluation of boiler chemical cleaning techniques

International Nuclear Information System (INIS)

1993-04-01

The EPRI/SGOG process, which has been selected by Ontario Hydro for use at the Bruce A station, is described. This process consists of alternating iron removal and copper removal steps, the two metals which comprise the bulk of the deposit in the Bruce A SGs. The iron removal solvent consists of ethylenediameinetetraacetic acid (EDTA), hydrazine, ammonium hydroxide and a proprietary corrosion inhibitor CCI-801. The copper removal solvent consists of EDTA, ethylene diamine and hydrogen peroxide. Ontario Hydro proposes to clean a bank of four SGs in parallel employing a total of six copper removal steps and four iron removal steps. Cleaning all eight SGs in a single Bruce A unit will generate 2,200 m 3 of liquid waste which will be treated by a wet air oxidation process. The iron and copper sludges will be buried in a landfill site while the liquid waste will be further treated by the Bruce sewage treatment plant. Some ammonia vapour will be generated through the wet air oxidation process and will be vented through a stack on top of the high bay of the spent solvent treatment plant. With the exception of the proprietary corrosion inhibitor, all chemicals that will be employed in the cleaning and waste treatment operations are standard industrial chemicals which are well characterized. No extraordinary hazards are anticipated with their use as long as adequate safety precautions are taken

[Assessment of decontamination processes: cleaning, disinfection and sterilization in dental practice in Poland in the years 2011-2012].

Science.gov (United States)

Röhm-Rodowald, Ewa; Jakimiak, Bozenna; Chojecka, Agnieszka; Zmuda-Baranowska, Magdalena; Kanclerski, Krzysztof

2012-01-01

Effective decontamination of instruments is a key element of infection control and the provision of high quality in dental care. The aim of the study was to evaluate the efficiency of decontamination procedures including cleaning, disinfection and sterilization of re-usable instruments in dental practices in Poland. The efficiency of disinfection and sterilization processes have been evaluated on the results of the questionnaires. The following information were taken into account: setting where disinfection and sterilization had been performed, preparation of dental equipment for sterilization (disinfection, washing and cleaning, packaging), the types of autoclaves and used types of sterilization cycles, routine monitoring and documentation of sterilization processes, treatment of handpieces and the frequency of surface decontamination. Data were collected from 43 dental practices (35 dental offices and 8 clinics). Disinfection and cleaning processes were performed manually in 63% of dental offices and ultrasonic baths were used in 53% of settings. Washer disinfectors were used in 23% of dental practices: in every researched clinic and in a few dental offices. All sterilization processes were performed in steam autoclaves, mainly in small steam sterilizers (81%). Dental handpieces were sterilized in 72% of practices, but only 33% of them performed sterilization in recommended cycle B. Sterilization processes were monitored with chemical indicators in 33% of practices. Biological monitoring of the processes was carried out at different intervals. Incorrect documentation of instruments and surfaces decontamination was recorded in several settings. There is still a need for improvement of decontamination processes in dental practice in Poland. Areas for improvement include: replacement of manual cleaning and disinfection processes with automatic processes, sterilization of dental handpieces after each patient, monitoring of a sterilization process with chemical and

Industrial rag cleaning process for the environmentally safe removal of petroleum-based solvents

International Nuclear Information System (INIS)

Fierro, J.V.

1993-01-01

A process for the cleaning of industrial rags contaminated with environmentally unsafe petroleum-based solvent is described, comprising the step of: (a) placing a load of the industrial rags in a mechanically driven rotary drum; (b) revolving the drum at a high speed sufficient to physically extract liquid petroleum-based solvent contaminate from the industrial rags; (c) routing the extracted petroleum-based solvent contaminate from the rotary drum to a waste solvent collection line for environmentally safe disposal; (d) revolving the rotary drum to cause a tumbling of the industrial rags while maintaining the temperature within the drum at below the flash point of the petroleum-based solvent; (e) intermittently forcing cold air and hot air through the rotary drum to vaporize solvent from the industrial rags; (f) routing the vaporized petroleum-based solvent contaminant from the rotary drum to a condenser wherein the petroleum-based solvent contaminate is condensed and thereafter further routing said condensed solvent to a waste collection line for environmentally safe disposal; and (g) cleaning the industrial rags in the presence of a dry cleaning solvent to remove residual petroleum-based solvents and soil

Generated forces and heat during the critical stages of friction stir welding and processing

Energy Technology Data Exchange (ETDEWEB)

Hussein, Sadiq Aziz; Tahir, Abd Salam Md; Izamshah, R. [University Teknikal Malaysia Melaka, Malacca (Malaysia)

2015-10-15

The solid-state behavior of friction stir welding process results in violent mechanical forces that should be mitigated, if not eliminated. Plunging and dwell time are the two critical stages of this welding process in terms of the generated forces and the related heat. In this study, several combinations of pre-decided penetration speeds, rotational speeds, tool designs, and dwell time periods were used to investigate these two critical stages. Moreover, a coupled-field thermal-structural finite element model was developed to validate the experimental results and the induced stresses. The experimental results revealed the relatively large changes in force and temperature during the first two stages compared with those during the translational tool movement stage. An important procedure to mitigate the undesired forces was then suggested. The model prediction of temperature values and their distribution were in good agreement with the experimental prediction. Therefore, the thermal history of this non-uniform heat distribution was used to estimate the induced thermal stresses. Despite the 37% increase in these stresses when 40 s dwell time was used instead of 5 s, these stresses showed no effect on the axial force values because of the soft material incidence and stir effects.

Generated forces and heat during the critical stages of friction stir welding and processing

International Nuclear Information System (INIS)

Hussein, Sadiq Aziz; Tahir, Abd Salam Md; Izamshah, R.

2015-01-01

The solid-state behavior of friction stir welding process results in violent mechanical forces that should be mitigated, if not eliminated. Plunging and dwell time are the two critical stages of this welding process in terms of the generated forces and the related heat. In this study, several combinations of pre-decided penetration speeds, rotational speeds, tool designs, and dwell time periods were used to investigate these two critical stages. Moreover, a coupled-field thermal-structural finite element model was developed to validate the experimental results and the induced stresses. The experimental results revealed the relatively large changes in force and temperature during the first two stages compared with those during the translational tool movement stage. An important procedure to mitigate the undesired forces was then suggested. The model prediction of temperature values and their distribution were in good agreement with the experimental prediction. Therefore, the thermal history of this non-uniform heat distribution was used to estimate the induced thermal stresses. Despite the 37% increase in these stresses when 40 s dwell time was used instead of 5 s, these stresses showed no effect on the axial force values because of the soft material incidence and stir effects

Heat exchanger cleaning

International Nuclear Information System (INIS)

Gatewood, J.R.

1980-01-01

A survey covers the various types of heat-exchange equipment that is cleaned routinely in fossil-fired generating plants, the hydrocarbon-processing industry, pulp and paper mills, and other industries; the various types, sources, and adverse effects of deposits in heat-exchange equipment; some details of the actual procedures for high-pressure water jetting and chemical cleaning of some specific pieces of equipment, including nuclear steam generators. (DN)

Validation of cleaning method for various parts fabricated at a Beryllium facility

Energy Technology Data Exchange (ETDEWEB)

Davis, Cynthia M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2015-12-15

This study evaluated and documented a cleaning process that is used to clean parts that are fabricated at a beryllium facility at Los Alamos National Laboratory. The purpose of evaluating this cleaning process was to validate and approve it for future use to assure beryllium surface levels are below the Department of Energy’s release limits without the need to sample all parts leaving the facility. Inhaling or coming in contact with beryllium can cause an immune response that can result in an individual becoming sensitized to beryllium, which can then lead to a disease of the lungs called chronic beryllium disease, and possibly lung cancer. Thirty aluminum and thirty stainless steel parts were fabricated on a lathe in the beryllium facility, as well as thirty-two beryllium parts, for the purpose of testing a parts cleaning method that involved the use of ultrasonic cleaners. A cleaning method was created, documented, validated, and approved, to reduce beryllium contamination.

The temporal evolution process from fluorescence bleaching to clean Raman spectra of single solid particles optically trapped in air

Science.gov (United States)

Gong, Zhiyong; Pan, Yong-Le; Videen, Gorden; Wang, Chuji

2017-12-01

We observe the entire temporal evolution process of fluorescence and Raman spectra of single solid particles optically trapped in air. The spectra initially contain strong fluorescence with weak Raman peaks, then the fluorescence was bleached within seconds, and finally only the clean Raman peaks remain. We construct an optical trap using two counter-propagating hollow beams, which is able to stably trap both absorbing and non-absorbing particles in air, for observing such temporal processes. This technique offers a new method to study dynamic changes in the fluorescence and Raman spectra from a single optically trapped particle in air.

A two-stage ceramic tile grout sealing process using a high power diode laser—Grout development and materials characteristics

Science.gov (United States)

Lawrence, J.; Li, L.; Spencer, J. T.

1998-04-01

Work has been conducted using a 60 Wcw high power diode laser (HPDL) in order to determine the feasibility and characteristics of sealing the void between adjoining ceramic tiles with a specially developed grout material having an impermeable enamel surface glaze. A two-stage process has been developed using a new grout material which consists of two distinct components: an amalgamated compound substrate and a glazed enamel surface; the amalgamated compound seal providing a tough, heat resistant bulk substrate, whilst the enamel provides an impervious surface. HPDL processing has resulted in crack free seals produced in normal atmospheric conditions. The basic process phenomena are investigated and the laser effects in terms of seal morphology, composition and microstructure are presented. Also, the resultant heat affects are analysed and described, as well as the effects of the shield gases, O 2 and Ar, during laser processing. Tiles were successfully sealed with power densities as low as 500 W/cm 2 and at rates up to 600 mm/min. Contact angle measurements revealed that due to the wettability characteristics of the amalgamated oxide compound grout (AOCG), laser surface treatment was necessary in order to alter the surface from a polycrystalline to a semi-amorphous structure, thus allowing the enamel to adhere. Bonding of the enamel to the AOCG and the ceramic tiles was identified as being principally due to van der Waals forces, and on a very small scale, some of the base AOCG material dissolving into the glaze.

Decontamination of polypropylene fabrics by dry cleaning

International Nuclear Information System (INIS)

Severa, J.; Knajfl, J.

1983-01-01

Polypropylene fabrics can efficiently be decontaminated by dry cleaning in benzine or perchloroethylene, this also in case the fabric was greased in addition to radioactive contamination. For heavily soiled fabric, it is advantageous to first dry clean it and then wash it. The positive effect was confirmed of intensifiers on the cleaning process, especially of benzine soap. In practice, its concentration should be selected within 1 and 10 g.dm - 3 . Decontamination by dry cleaning and subsequent washing is advantageous in that that the resulting activity of waste water from the laundry is low. Radioactive wastes from the dry cleaning process have a low weight and can be handled as solid waste. (M.D.)

Unintentionality of affective attention across visual processing stages

Directory of Open Access Journals (Sweden)

Andero eUusberg

2013-12-01

Full Text Available Affective attention involves bottom-up perceptual selection that prioritizes motivationally significant stimuli. To clarify the extent to which this process is automatic, we investigated the dependence of affective attention on the intention to process emotional meaning. Affective attention was manipulated by presenting IAPS images with variable arousal and intentionality by requiring participants to make affective and non-affective evaluations. Polytomous rather than binary decisions were required from the participants in order to elicit relatively deep emotional processing. The temporal dynamics of prioritized processing were assessed using Early Posterior Negativity (EPN, 175-300 ms as well as P3-like (P3, 300 – 500 ms and Slow Wave (SW, 500 – 1500 ms portions of the Late Positive Potential. All analysed components were differentially sensitive to stimulus categories suggesting that they indeed reflect distinct stages of motivational significance encoding. The intention to perceive emotional meaning had no effect on EPN, an additive effect on P3, and an interactive effect on SW. We concluded that affective attention went from completely unintentional during the EPN to partially unintentional during P3 and SW where top-down signals, respectively, complemented and modulated bottom-up differences in stimulus prioritization. The findings were interpreted in light of two-stage models of visual perception by associating the EPN with large-capacity initial relevance detection and the P3 as well as SW with capacity-limited consolidation and elaboration of affective stimuli.

A Tale of Two Climate Policies: Political Economy of British Columbia's Carbon Tax and Clean Electricity Standard

OpenAIRE

Ekaterina Rhodes; Mark Jaccard

2013-01-01

In 2007-08, British Columbia implemented two significant climate policies: the first broadly based carbon tax and the first almost 100-percent "clean" electricity standard in North America. We describe the key design characteristics of these policies and analyse them against the criteria of greenhouse gas (GHG) emissions reductions, economic efficiency, administrative feasibility, and public acceptance. We find that the clean electricity standard is estimated to reduce four to six times more ...

Dynamic analysis of the CRBRP clean-up system (three stage aqueous scrubber)

International Nuclear Information System (INIS)

Kyi, R.; Bijlani, C.; Fazekas, P.; Dajani, A.

1981-01-01

The CRBRP containment clean-up system design required the determination of the thermal-hydraulic performance of the system during its projected operating cycle. The reduced scale component tests at HEDL provided valuable information about the generic performance of the components; however, due to the limitations of the test facility the exact simulation of the actual CRBRP conditions was not feasible. A computer program was developed to permit dynamic system analysis of the full size air cleaning system. The dynamic system analysis considered the mass and energy balances across each component. In addition to the major filtration system components, the system modeling included the supporting fluid system components such as pumps, tanks and heat exchangers. Variable gas flow, temperature, chemical concentrations, and other system parameters were also modeled. Fission product heat, chemical reaction heat and heat of solution were considered. The analysis results provided sodium hydroxide solution concentrations and temperatures, gas temperatures and other variables at the various components within the air cleaning system for each calculated time interval. The accuracy of the computer modeling was verified by comparing the calculated results with HEDL test data. The comparison indicated a better than +-10% agreement with the test data. The analysis results provided the basis for the selection of the system components

Exhaust gas clean up process

Science.gov (United States)

Walker, R.J.

1988-06-16

A method of cleaning an exhaust gas containing particulates, SO/sub 2/ and NO/sub x/ is described. The method involves prescrubbing with water to remove HCl and most of the particulates, scrubbing with an aqueous absorbent containing a metal chelate and dissolved sulfite salt to remove NO/sub x/ and SO/sub 2/, and regenerating the absorbent solution by controlled heating, electrodialysis and carbonate salt addition. The NO/sub x/ is removed as N/sub 2/ gas or nitrogen sulfonate ions and the oxides of sulfur are removed as a valuable sulfate salt. 4 figs.

Application of physical separation techniques in uranium resources processing

International Nuclear Information System (INIS)

Padmanabhan, N.P.H.; Sreenivas, T.

2008-01-01

The planned economic growth of our country and energy security considerations call for increasing the overall electricity generating capabilities with substantial increase in the zero-carbon and clean nuclear power component. Although India is endowed with vast resources of thorium, its utilization can commence only after the successful completion of the first two stages of nuclear power programme, which use natural uranium in the first stage and natural uranium plus plutonium in the second stage. For the successful operation of first stage, exploration and exploitation activities for uranium should be vigorously followed. This paper reviews the current status of physical beneficiation in processing of uranium ores and discusses its applicability to recover uranium from low grade and below-cut-off grade ores in Indian context. (author)

A Dual-Stage Two-Phase Model of Selective Attention

Science.gov (United States)

Hubner, Ronald; Steinhauser, Marco; Lehle, Carola

2010-01-01

The dual-stage two-phase (DSTP) model is introduced as a formal and general model of selective attention that includes both an early and a late stage of stimulus selection. Whereas at the early stage information is selected by perceptual filters whose selectivity is relatively limited, at the late stage stimuli are selected more efficiently on a…

Stages in the research process.

Science.gov (United States)

Gelling, Leslie

2015-03-04

Research should be conducted in a systematic manner, allowing the researcher to progress from a general idea or clinical problem to scientifically rigorous research findings that enable new developments to improve clinical practice. Using a research process helps guide this process. This article is the first in a 26-part series on nursing research. It examines the process that is common to all research, and provides insights into ten different stages of this process: developing the research question, searching and evaluating the literature, selecting the research approach, selecting research methods, gaining access to the research site and data, pilot study, sampling and recruitment, data collection, data analysis, and dissemination of results and implementation of findings.

Fluorescent Penetrant INSPECTION—CLEANING Study Update

Science.gov (United States)

Eisenmann, D.; Brasche, L.

2009-03-01

Fluorescent penetrant inspection (FPI) is widely used in the aviation industry and other industries for surface-breaking crack detection. As with all inspection methods, adherence to the process parameters is critical to the successful detection of defects. There is variety of lubricants and surface coatings used in the aviation industry which must be removed prior to FPI. Before the FPI process begins, components are cleaned using a variety of cleaning methods which are selected based on the alloy and the soil types which must be removed. It is also important that the cleaning process not adversely affect the FPI process. From the first three phases of this project it has been found that a hot water rinse can aid in the detection process when using this nondestructive method.

FY1995 development of a clean CVD process by evaluation and control of gas phase nucleation phenomena; 1995 nendo kisokaku seisei gensho no hyoka to seigyo ni yoru clean CVD process no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

The purpose of this study is to develop a high-rate and clean chemical vapor deposition (CVD) process as a breakthrough technique to overcome the problems that particles generated in the gas phase during CVD process for preparation of functional thin films cause reduced product yield and deterioration of the films. In the CVD process proposed here, reactant gas and generated particles are electrically charged to control the motion of them with an electric field. In this study, gas-phase nucleation phenomena are evaluated both theoretically and experimentally. A high-rate, ionized CVD method is first developed, in which reactant gas and generated particles are charged with negative ions generated from a radioisotope source and the UV/photoelectron method, and the motion of the charged gas and particles is controlled with an electric field. Charging and transport processes of fine particles are then investigated experimentally and theoretically to develop a clean CVD method in which generated particles are removed with the electric forces. As a result, quantitative evaluation of the charging and transport process was made possible. We also developed devices for measuring the size distribution and concentration of fine particles in low pressure gas such as those found in plasma CVD processes. In addition, numerical simulation and experiments in this study for a TEOS/O{sub 3} CVD process to prepare thin films could determine reaction rates which have not been known so far and give information on selecting good operation conditions for the process. (NEDO)

[Comparison research on two-stage sequencing batch MBR and one-stage MBR].

Science.gov (United States)

Yuan, Xin-Yan; Shen, Heng-Gen; Sun, Lei; Wang, Lin; Li, Shi-Feng

2011-01-01

Aiming at resolving problems in MBR operation, like low nitrogen and phosphorous removal efficiency, severe membrane fouling and etc, comparison research on two-stage sequencing batch MBR (TSBMBR) and one-stage aerobic MBR has been done in this paper. The results indicated that TSBMBR owned advantages of SBR in removing nitrogen and phosphorous, which could make up the deficiency of traditional one-stage aerobic MBR in nitrogen and phosphorous removal. During steady operation period, effluent average NH4(+) -N, TN and TP concentration is 2.83, 12.20, 0.42 mg/L, which could reach domestic scenic environment use. From membrane fouling control point of view, TSBMBR has lower SMP in supernatant, specific trans-membrane flux deduction rate, membrane fouling resistant than one-stage aerobic MBR. The sedimentation and gel layer resistant of TSBMBR was only 6.5% and 33.12% of one-stage aerobic MBR. Besides high efficiency in removing nitrogen and phosphorous, TSBMBR could effectively reduce sedimentation and gel layer pollution on membrane surface. Comparing with one-stage MBR, TSBMBR could operate with higher trans-membrane flux, lower membrane fouling rate and better pollutants removal effects.

A novel flow sensor based on resonant sensing with two-stage microleverage mechanism

Science.gov (United States)

Yang, B.; Guo, X.; Wang, Q. H.; Lu, C. F.; Hu, D.

2018-04-01

The design, simulation, fabrication, and experiments of a novel flow sensor based on resonant sensing with a two-stage microleverage mechanism are presented in this paper. Different from the conventional detection methods for flow sensors, two differential resonators are adopted to implement air flow rate transformation through two-stage leverage magnification. The proposed flow sensor has a high sensitivity since the adopted two-stage microleverage mechanism possesses a higher amplification factor than a single-stage microleverage mechanism. The modal distribution and geometric dimension of the two-stage leverage mechanism and hair are analyzed and optimized by Ansys simulation. A digital closed-loop driving technique with a phase frequency detector-based coordinate rotation digital computer algorithm is implemented for the detection and locking of resonance frequency. The sensor fabricated by the standard deep dry silicon on a glass process has a device dimension of 5100 μm (length) × 5100 μm (width) × 100 μm (height) with a hair diameter of 1000 μm. The preliminary experimental results demonstrate that the maximal mechanical sensitivity of the flow sensor is approximately 7.41 Hz/(m/s)2 at a resonant frequency of 22 kHz for the hair height of 9 mm and increases by 2.42 times as hair height extends from 3 mm to 9 mm. Simultaneously, a detection-limit of 3.23 mm/s air flow amplitude at 60 Hz is confirmed. The proposed flow sensor has great application prospects in the micro-autonomous system and technology, self-stabilizing micro-air vehicles, and environmental monitoring.

Energy demand in Portuguese manufacturing: a two-stage model

International Nuclear Information System (INIS)

Borges, A.M.; Pereira, A.M.

1992-01-01

We use a two-stage model of factor demand to estimate the parameters determining energy demand in Portuguese manufacturing. In the first stage, a capital-labor-energy-materials framework is used to analyze the substitutability between energy as a whole and other factors of production. In the second stage, total energy demand is decomposed into oil, coal and electricity demands. The two stages are fully integrated since the energy composite used in the first stage and its price are obtained from the second stage energy sub-model. The estimates obtained indicate that energy demand in manufacturing responds significantly to price changes. In addition, estimation results suggest that there are important substitution possibilities among energy forms and between energy and other factors of production. The role of price changes in energy-demand forecasting, as well as in energy policy in general, is clearly established. (author)

Laser cleaning of sulfide scale on compressor impeller blade

International Nuclear Information System (INIS)

Tang, Q.H.; Zhou, D.; Wang, Y.L.; Liu, G.F.

2015-01-01

Highlights: • The effects of sulfide layers and fluence values on the mechanism of laser cleaning were experimentally established. • The specimen surface with sulfide scale becomes slightly smoother than that before laser cleaning. • The mechanism of laser cleaning the sulfide scale of stainless steel is spallation without oxidization. • It would avoid chemical waste and dust pollution using a fiber laser instead of using nitric acids or sandblasting. - Abstract: Sulfide scale on the surface of a compressor impeller blade can considerably reduce the impeller performance and its service life. To prepare for subsequent remanufacturing, such as plasma spraying, it needs to be removed completely. In the corrosion process on an FV(520)B stainless steel, sulfide scale is divided into two layers because of different outward diffusion rates of Cr, Ni and Fe. In this paper, the cleaning threshold values of the upper and inner layers and the damage threshold value of the substrate were investigated using a pulsed fiber laser. To obtain experimental evidence, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and 3D surface profilometry were employed to investigate the two kinds of sulfide layers on specimens before, during, and after laser cleaning.

Application of two-stage biofilter system for the removal of odorous compounds.

Science.gov (United States)

Jeong, Gwi-Taek; Park, Don-Hee; Lee, Gwang-Yeon; Cha, Jin-Myeong

2006-01-01

Biofiltration is a biological process which is considered to be one of the more successful examples of biotechnological applications to environmental engineering, and is most commonly used in the removal of odoriferous compounds. In this study, we have attempted to assess the efficiency with which both single and complex odoriferous compounds could be removed, using one- or two-stage biofiltration systems. The tested single odor gases, limonene, alpha-pinene, and iso-butyl alcohol, were separately evaluated in the biofilters. Both limonene and alpha-pinene were removed by 90% or more EC (elimination capacity), 364 g/m3/h and 321 g/m3/h, respectively, at an input concentration of 50 ppm and a retention time of 30 s. The iso-butyl alcohol was maintained with an effective removal yield of more than 90% (EC 375 g/m3/h) at an input concentration of 100 ppm. The complex gas removal scheme was applied with a 200 ppm inlet concentration of ethanol, 70 ppm of acetaldehyde, and 70 ppm of toluene with residence time of 45 s in a one- or two-stage biofiltration system. The removal yield of toluene was determined to be lower than that of the other gases in the one-stage biofilter. Otherwise, the complex gases were sufficiently eliminated by the two-stage biofiltration system.

The influence of magnetic field strength in ionization stage on ion transport between two stages of a double stage Hall thruster

International Nuclear Information System (INIS)

Yu Daren; Song Maojiang; Li Hong; Liu Hui; Han Ke

2012-01-01

It is futile for a double stage Hall thruster to design a special ionization stage if the ionized ions cannot enter the acceleration stage. Based on this viewpoint, the ion transport under different magnetic field strengths in the ionization stage is investigated, and the physical mechanisms affecting the ion transport are analyzed in this paper. With a combined experimental and particle-in-cell simulation study, it is found that the ion transport between two stages is chiefly affected by the potential well, the potential barrier, and the potential drop at the bottom of potential well. With the increase of magnetic field strength in the ionization stage, there is larger plasma density caused by larger potential well. Furthermore, the potential barrier near the intermediate electrode declines first and then rises up while the potential drop at the bottom of potential well rises up first and then declines as the magnetic field strength increases in the ionization stage. Consequently, both the ion current entering the acceleration stage and the total ion current ejected from the thruster rise up first and then decline as the magnetic field strength increases in the ionization stage. Therefore, there is an optimal magnetic field strength in the ionization stage to guide the ion transport between two stages.

Si-compatible cleaning process for graphene using low-density inductively coupled plasma.

Science.gov (United States)

Lim, Yeong-Dae; Lee, Dae-Yeong; Shen, Tian-Zi; Ra, Chang-Ho; Choi, Jae-Young; Yoo, Won Jong

2012-05-22

We report a novel cleaning technique for few-layer graphene (FLG) by using inductively coupled plasma (ICP) of Ar with an extremely low plasma density of 3.5 × 10(8) cm(-3). It is known that conventional capacitively coupled plasma (CCP) treatments destroy the planar symmetry of FLG, giving rise to the generation of defects. However, ICP treatment with extremely low plasma density is able to remove polymer resist residues from FLG within 3 min at a room temperature of 300 K while retaining the carbon sp(2)-bonding of FLG. It is found that the carrier mobility and charge neutrality point of FLG are restored to their pristine defect-free state after the ICP treatment. Considering the application of graphene to silicon-based electronic devices, such a cleaning method can replace thermal vacuum annealing, electrical current annealing, and wet-chemical treatment due to its advantages of being a low-temperature, large-area, high-throughput, and Si-compatible process.

CHEMICAL AND ENERGETIC CONTENT OF CORN BEFORE AND AFTER PRE-CLEANING

Directory of Open Access Journals (Sweden)

Sandra Iara Furtado Costa Rodrigues

2015-04-01

Full Text Available The poultry industry normally has little control over the raw material that arrives at the processing plant. This experiment aimed to evaluate chemical and energetic quality of corn obtained in a feed mill before and after pre-cleaning. Twenty samples of 30 kg of corn each were taken from trucks delivering corn to the mill. The trucks were then unloaded and the material passed through a pre-cleaning process when another sample was taken. Samples were graded and physical properties evaluated: density (g/L, grain percentages of foreign material, impurities, fragments, broken, soft, insect damaged, fire-burnt, fermented, damaged, cracked and fine particles, as well as chemical composition analysis: Apparent metabolizable energy for poultry (AME, ether extract (EE, crude fiber (CF, starch (STA, water activity (WA, crude protein (CP, digestible and total lysine, methionine, cystine, threonine, tryptophan, valine, isoleucine, leucine, phenylalanine, histidine and arginine. The experiment was a randomized design with two treatments (before and after pre-cleaning and twenty replications. Data was analyzed using SAS ® and treatment differences obtained using F test. Correlations and principal components were calculated. There was a decrease in density after the pre-cleaning process, which was probably due to the removal of earth and stones rather than grain and its fractions. Significant increases were found for insect damage, fermented and damaged grain while fire-burn was significantly reduced after the pre-cleaning process. Starch increased after pre-cleaning which is a result of contaminants that normally are poor in this carbohydrate, but fiber levels increased too. Apparent metabolizable energy, aminoacids, digestible (P<0.05 and total (P<0.05 histidine, total lysine and methionine (P<0.1 levels were reduced after pre-cleaning. Density was higher when there were fewer impurities such as straw, husk or small grains. Broken corn was positively

Water cleaning by pulsed corona discharges

NARCIS (Netherlands)

Grabowski, L.R.; Veldhuizen, van E.M.; Rutgers, W.R.

2004-01-01

Direct electrical energization methods for water cleaning are under investigation in the framework of the ytriD-project1. The emphasis of the first stage of the project is optimization of the reactor configuration regarding the energy efficiency. A comparison is made between a batch reactor and an

Systematic development of a two-stage fed-batch process for lipid accumulation in Rhodotorula glutinis.

Science.gov (United States)

Lorenz, Eric; Runge, Dennis; Marbà-Ardébol, Anna-Maria; Schmacht, Maximilian; Stahl, Ulf; Senz, Martin

2017-03-20

The application of oleaginous yeast cells as feed supplement, for instance in aqua culture, can be a meaningful alternative for fish meal and oil additives. Therefore, a two-stage fed-batch process split into growth and lipogenesis phase was systematically developed to enrich the oleaginous yeast Rhodotorula glutinis Rh-00301 with high amounts of lipids at industrial relevant biomasses. Thereby, the different carbon sources glucose, sucrose and glycerol were investigated concerning their abilities to serve as a suited raw material for growth and/or lipid accumulation. With the background of economic efficiency C/N ratios of 40, 50 and 70 were investigated as well. It became apparent that glycerol is an improper carbon source most likely because of the passive diffusion of this compound caused by absence of active transporters. The opposite was observed for sucrose, which is the main carbon source in molasses. Finally, an industrially applicable process was successfully established that ensures biomasses of 106±2gL -1 combined with an attractive lipid content of 63±6% and a high lipid-substrate yield (Y L/S ) of 0.18±0.02gg -1 in a short period of time (84h). Furthermore, during these studies a non-negligible formation of the by-product glycerol was detected. This characteristic of R. glutinis is discussed related to other oleaginous yeasts, where glycerol formation is absent. Nevertheless, due to modifications in the feeding procedure, the formation of glycerol could have been reduced but not avoided. Copyright © 2017 Elsevier B.V. All rights reserved.

Washing away your sins in the brain: physical cleaning and priming of cleaning recruit different brain networks after moral threat.

Science.gov (United States)

Tang, Honghong; Lu, Xiaping; Su, Rui; Liang, Zilu; Mai, Xiaoqin; Liu, Chao

2017-07-01

The association between moral purity and physical cleanliness has been widely discussed recently. Studies found that moral threat initiates the need of physical cleanliness, but actual physical cleaning and priming of cleaning have inconsistent effects on subsequent attitudes and behaviors. Here, we used resting-state functional magnetic resonance imaging to explore the underlying neural mechanism of actual physical cleaning and priming of cleaning. After recalling moral transgression with strong feelings of guilt and shame, participants either actually cleaned their faces with a wipe or were primed with cleanliness through viewing its pictures. Results showed that actual physical cleaning reduced the spontaneous brain activities in the right insula and MPFC, regions that involved in embodied moral emotion processing, while priming of cleaning decreased activities in the right superior frontal gyrus and middle frontal gyrus, regions that participated in executive control processing. Additionally, actual physical cleaning also changed functional connectivity between insula/MPFC and emotion related regions, whereas priming of cleaning modified connectivity within both moral and sensorimotor areas. These findings revealed that actual physical cleaning and priming of cleaning led to changes in different brain regions and networks, providing neural evidence for the inconsistent effects of cleanliness on subsequent attitudes and behaviors. © The Author (2017). Published by Oxford University Press.

Influence of two-stage annealing treatment on critical current of bronze-processed multifilamentary Nb/sub 3/Sn superconducting materials

International Nuclear Information System (INIS)

Ochiai, S.; Osamura, K.; Ryoji, M.

1987-01-01

The influence of changes of volume fraction of Nb/sub 3/Sn, grain size and upper critical magnetic field due to two-stage annealing treatment (low temperature annealing to form fine grains + high temperature annealing to raise upper critical magnetic field) on overall critical current and critical current density were studied at magnetic field of 3-15 T. When annealing temperature was low (773-923 K) and the volume fraction of Nb/sub 3/Sn was low in first stage annealing, second stage annealing could raise the overall critical current over the range of the applied magnetic field due to increase in upper critical magnetic field H/sub c2/ and volume fraction of Nb/sub 3/Sn accompanying with reduction in Sn concentration in the bronze matrix, which played a role to reduce residual strain in Nb/sub 3/Sn, leading to high H/sub c2/ although the loss in pinning force arose from the coarsening of the grains. When the annealing temperature was high (973 K) and the Nb/sub 3/Sn was formed until the Sn was consumed in the first stage, second stage annealing could not raise the critical current due to increase in grain size and no effective increase in H/sub c2/. The critical current density at low magnetic fields below several Teslas was reduced by the second stage annealing due to increase in grain size but that at high fields was raised due to increase in high H/sub c2/. The reverse two-stage annealing treatment (high temperature annealing in the first stage+low temperature annealing in the second stage) reduced the H/sub c2/ slightly with increasing second stage annealing temperature and time. The critical current density at low magnetic fields was determined mainly by the grain size and that at high fields was determined by the combination of the upper critical field and grain size

Study for process and equipment design of wet gelation stages in vibropacking process

International Nuclear Information System (INIS)

Tanimoto, Ryoji; Kikuchi, Toshiaki; Tanaka, Hirokazu; Amino, Masaki; Yanai, Minoru

2004-02-01

Process and layout design of external wet gelation stages in vibropacking process was examined for the feasibility study of commercialized FBR cycle system. In this study, following process stages for the oxide core fuel production line were covered, that is, solidification, washing, drying, calcination, reduction, sintering stages including interim storage of sintering particles and reagent recovery stage. The main results obtained by this study are as follows: (1) Based on the process examination results conducted previously, process-flow, mass-balance and number of production line/equipment were clarified. The process is covered from the receive tank of feed solution to the interim storage equipment. Reagent recovery process-flow, mass-balance were also clarified. And preliminary design of the main equipment was reexamined. (2) Normal operation procedure and the procedure after process failure were summarized along with a remote automated operation procedure. Operation sequence of each production line was mapped out by using a time-chart. (3) Design outline of reagent recovery equipments, installed to recover waste liquid from the wet gelation stages in the view of environmental impact were examined. Effective techniques such as collection of solvent, residue waste treatment method were examined its applicability and selected. Schematic block diagram was presented. (4) Analytical items and analyzing apparatus were extracted taking into account of quality control and process management. Analytical sample taking position and frequency of sampling were also examined. (5) A schematic layout drawing of main manufacturing process and reagent recovery process was presented taking into account of material handling. (6) A feature of the operating rate at each process stage was examined by analyzing failure rate reliability of each component. applying the reliability-centred method. (RCM), the operating rate was evaluated and annual maintenance period was estimated using

Clean utilization of coal

International Nuclear Information System (INIS)

Yueruem, Y.

1992-01-01

This volume contains 23 lectures presented at the Advanced Study Institute on 'Chemistry and Chemical Engineering of Catalytic Solid Fuel Conversion for the Production of Clean Synthetic Fuels', which was held at Akcay, Edremit, Turkey, between 21 July and August 3, 1991. Three main subjects: structure and reactivity of coal; cleaning of coal and its products, and factors affecting the environmental balance of energy usage and solutions for the future, were discussed in the Institute and these are presented under six groups in the book: Part 1. Structure and reactivity of coal; Part 2. Factors affecting environmental balance; Part 3. Pre-usage cleaning operations and processes; Part 4. Upgrading of coal liquids and gases; Part 5. Oxygen enriched processes; and Part 6. Probable future solution for energy and pollution problems. Separate abstracts have been prepared for all the lectures

Single-stage Acetabular Revision During Two-stage THA Revision for Infection is Effective in Selected Patients.

Science.gov (United States)

Fink, Bernd; Schlumberger, Michael; Oremek, Damian

2017-08-01

The treatment of periprosthetic infections of hip arthroplasties typically involves use of either a single- or two-stage (with implantation of a temporary spacer) revision surgery. In patients with severe acetabular bone deficiencies, either already present or after component removal, spacers cannot be safely implanted. In such hips where it is impossible to use spacers and yet a two-stage revision of the prosthetic stem is recommended, we have combined a two-stage revision of the stem with a single revision of the cup. To our knowledge, this approach has not been reported before. (1) What proportion of patients treated with single-stage acetabular reconstruction as part of a two-stage revision for an infected THA remain free from infection at 2 or more years? (2) What are the Harris hip scores after the first stage and at 2 years or more after the definitive reimplantation? Between June 2009 and June 2014, we treated all patients undergoing surgical treatment for an infected THA using a single-stage acetabular revision as part of a two-stage THA exchange if the acetabular defect classification was Paprosky Types 2B, 2C, 3A, 3B, or pelvic discontinuity and a two-stage procedure was preferred for the femur. The procedure included removal of all components, joint débridement, definitive acetabular reconstruction (with a cage to bridge the defect, and a cemented socket), and a temporary cemented femoral component at the first stage; the second stage consisted of repeat joint and femoral débridement and exchange of the femoral component to a cementless device. During the period noted, 35 patients met those definitions and were treated with this approach. No patients were lost to followup before 2 years; mean followup was 42 months (range, 24-84 months). The clinical evaluation was performed with the Harris hip scores and resolution of infection was assessed by the absence of clinical signs of infection and a C-reactive protein level less than 10 mg/L. All

Hydrogen and methane production from desugared molasses using a two‐stage thermophilic anaerobic process

DEFF Research Database (Denmark)

Kongjan, Prawit; O-Thong, Sompong; Angelidaki, Irini

2013-01-01

Hydrogen and methane production from desugared molasses by a two‐stage thermophilic anaerobic process was investigated in a series of two up‐flow anaerobic sludge blanket (UASB) reactors. The first reactor that was dominated with hydrogen‐producing bacteria of Thermoanaerobacterium thermosaccharo......Hydrogen and methane production from desugared molasses by a two‐stage thermophilic anaerobic process was investigated in a series of two up‐flow anaerobic sludge blanket (UASB) reactors. The first reactor that was dominated with hydrogen‐producing bacteria of Thermoanaerobacterium...... molasses. Furthermore, the mixed gas with a volumetric content of 16.5% H2, 38.7% CO2, and 44.8% CH4, containing approximately 15% energy by hydrogen is viable to be bio‐hythane....

Enhanced coproduction of hydrogen and methane from cornstalks by a three-stage anaerobic fermentation process integrated with alkaline hydrolysis.

Science.gov (United States)

Cheng, Xi-Yu; Liu, Chun-Zhao

2012-01-01

A three-stage anaerobic fermentation process including H(2) fermentation I, H(2) fermentation II, methane fermentation was developed for the coproduction of hydrogen and methane from cornstalks. Hydrogen production from cornstalks using direct microbial conversion by Clostridium thermocellum 7072 was markedly enhanced in the two-stage thermophilic hydrogen fermentation process integrated with alkaline treatment. The highest total hydrogen yield from cornstalks in the two-stage fermentation process reached 74.4 mL/g-cornstalk. The hydrogen fermentation effluents and alkaline hydrolyzate were further used for methane fermentation by anaerobic granular sludge, and the total methane yield reached 205.8 mL/g-cornstalk. The total energy recovery in the three-stage anaerobic fermentation process integrated with alkaline hydrolysis reached 70.0%. Copyright © 2011 Elsevier Ltd. All rights reserved.

Two-stage continuous process of methyl ester from high free fatty acid mixed crude palm oil using static mixer coupled with high-intensity of ultrasound

International Nuclear Information System (INIS)

Somnuk, Krit; Smithmaitrie, Pruittikorn; Prateepchaikul, Gumpon

2013-01-01

Highlights: • Mixed crude palm oil was used in the two-step continuous process. • Two-step continuous process was performed using static mixer coupled with ultrasound. • The maximum obtained yield was 92.5 vol.% after the purification process. • The residence time less than 20 s was achieved in ultrasonic reactors. - Abstract: The two-stage continuous process of methyl ester from high free fatty acid (FFA) mixed crude palm oil (MCPO) was performed by using static mixer coupled with high-intensity of ultrasound. The 2 × 1000 W ultrasonic homogenizers were operated at 18 kHz frequency in the 2 × 100 mL continuous reactors. For the first-step, acid-catalyzed esterification was employed with 18 vol.% of methanol, 2.7 vol.% of sulfuric acid, 60 °C of temperature, and 20 L h −1 of MCPO flow rate, for reducing the acid value from 28 mg KOH g −1 to less than 2 mg KOH g −1 . For the second-step, base-catalyzed transesterification was carried out under 18 vol.% of methanol, 8 g KOH L −1 of oil, and 20 L h −1 of esterified oil flow rate at 30 °C. The high yields of esterified oil and crude biodiesel were attained within the residence time of less than 20 s in the ultrasonic reactors. The yields of each stage process were: 103.3 vol.% of esterified oil, 105.4 vol.% of crude biodiesel, and 92.5 vol.% of biodiesel when compared with 100 vol.% MCPO. The quality of the biodiesel meets the specification of biodiesel standard in Thailand

Manufacturing of NAA laboratory clean room

International Nuclear Information System (INIS)

Suwoto; Hasibuan, Djaruddin

2001-01-01

The ''NAA laboratory clean room'' has been built in the Reactor Serba Guna G.A. Siwabessy building. The erection of ''AAN laboratory clean room'' doing by started of preparation of the ''manufacturing procedure'' refer to ''Design and manufacturing neutron activation analysis clean room laboratory''. Manufacturing process and erection doing refer to procedures makes. By providing of the ''AAN laboratory clean room'' can be cocluded that the research activity and the user sevises in P2TRR well meet to be done

Technical support for the Ohio Clean Coal Technology Program. Volume 2, Baseline of knowledge concerning process modification opportunities, research needs, by-product market potential, and regulatory requirements: Final report

Energy Technology Data Exchange (ETDEWEB)

Olfenbuttel, R.; Clark, S.; Helper, E.; Hinchee, R.; Kuntz, C.; Means, J.; Oxley, J.; Paisley, M.; Rogers, C.; Sheppard, W.; Smolak, L. [Battelle, Columbus, OH (United States)

1989-08-28

This report was prepared for the Ohio Coal Development Office (OCDO) under Grant Agreement No. CDO/R-88-LR1 and comprises two volumes. Volume 1 presents data on the chemical, physical, and leaching characteristics of by-products from a wide variety of clean coal combustion processes. Volume 2 consists of a discussion of (a) process modification waste minimization opportunities and stabilization considerations; (b) research and development needs and issues relating to clean coal combustion technologies and by-products; (c) the market potential for reusing or recycling by-product materials; and (d) regulatory considerations relating to by-product disposal or reuse.

Control strategy research of two stage topology for pulsed power supply

International Nuclear Information System (INIS)

Shi Chunfeng; Wang Rongkun; Huang Yuzhen; Chen Youxin; Yan Hongbin; Gao Daqing

2013-01-01

A kind of pulsed power supply of HIRFL-CSR was introduced, the ripple and the current error of the topological structure of the power in the operation process were analyzed, and two stage topology of pulsed power supply was given. The control strategy was simulated and the experiment was done in digital power platform. The results show that the main circuit structure and control method are feasible. (authors)

Researches in increase of efficiency of electrokinetic process of ground cleaning from radionuclides

International Nuclear Information System (INIS)

Prozorov, L.B.; Shcheglov, M.Y.; Nikolaevsky, V.B.; Tkachenko, A.V.

2003-01-01

Potentially perspective method of decontamination of ground is electrokinetic method, which basic advantage consists in an opportunity of its application for clearing ground with low filtering by ability directly on a place of local contaminated (in situ). Thus moving the large volumes of the contaminated ground is excluded. Base of this method is the processes of electromigration and electro-osmotic, proceeding in a contaminated ground lay at imposing an electrical field of a constant current. Electrokinetic method of cleaning of ground from radionuclides provides their transfer in water-soluble, mobile form, carry as positive or negative ions under influence of an electrical field into electrode chambers with their subsequent recycling.Electrokinetic method in practice can be realized as follows: in the contaminated ground establish special electrode devices, fill their electrolyte and connect to a source of a constant current. Formed in the anode device as a result of electrochemical decomposition of water the ions of hydrogen under action of an electrical field move to the cathode, thus cooperate with a ground and superside cations of radioactive elements. Desorbed cations of contaminate act in catholyte, which periodically or continuously is exposed to clearing, for example, on sorption column. Last years the experts MosNPO Radon carry out complex researches directed on development of electrokinetic technology of cleaning ground from radionuclides and heavy metals. To the present time laboratory and bench tests of electrokinetic method are carried out. The basic attention at study of process of cleaning was given to objects contaminated Cs-137, most difficult recovery an element, which is strongly fixed by clay minerals and can enter into crystal structure. (authors)

Influence of Cu(NO32 initiation additive in two-stage mode conditions of coal pyrolytic decomposition

Directory of Open Access Journals (Sweden)

Larionov Kirill

2017-01-01

Full Text Available Two-stage process (pyrolysis and oxidation of brown coal sample with Cu(NO32 additive pyrolytic decomposition was studied. Additive was introduced by using capillary wetness impregnation method with 5% mass concentration. Sample reactivity was studied by thermogravimetric analysis with staged gaseous medium supply (argon and air at heating rate 10 °C/min and intermediate isothermal soaking. The initiative additive introduction was found to significantly reduce volatile release temperature and accelerate thermal decomposition of sample. Mass-spectral analysis results reveal that significant difference in process characteristics is connected to volatile matter release stage which is initiated by nitrous oxide produced during copper nitrate decomposition.

Two-stage soil infiltration treatment system for treating ammonium wastewaters of low COD/TN ratios.

Science.gov (United States)

Lei, Zhongfang; Wu, Ting; Zhang, Yi; Liu, Xiang; Wan, Chunli; Lee, Duu-Jong; Tay, Joo-Hwa

2013-01-01

Soil infiltration treatment (SIT) is ineffective to treat ammonium wastewaters of total nitrogen (TN) > 100 mg l(-1). This study applied a novel two-stage SIT process for effective TN removal from wastewaters of TN>100 mg l(-1) and of chemical oxygen demand (COD)/TN ratio of 3.2-8.6. The wastewater was first fed into the soil column (stage 1) at hydraulic loading rate (HLR) of 0.06 m(3) m(-2) d(-1) for COD removal and total phosphorus (TP) immobilization. Then the effluent from stage 1 was fed individually into four soil columns (stage 2) at 0.02 m(3) m(-2) d(-1) of HLR with different proportions of raw wastewater as additional carbon source. Over the one-year field test, balanced nitrification and denitrification in the two-stage SIT revealed excellent TN removal (>90%) from the tested wastewaters. Copyright © 2012 Elsevier Ltd. All rights reserved.

Steam generator chemical cleaning demonstration test No. 1 in a pot boiler

International Nuclear Information System (INIS)

Key, G.L.; Helyer, M.H.

1981-04-01

The effectiveness of the Electric Power Research Institute (EPRI Mark I) chemical cleaning solvent process was tested utilizing a 12 tube pot boiler that had previously been fouled and dented under 30 days of high chloride fault chemistry operation. Specifically, the intent of this chemical cleaning test was to: (1) dissolve sludge from the tubesheet, (2) remove non-protective magnetite from dented tube/support crevice regions, and (3) quantify the extent of corrosion of steam generator material during the test. Two laboratory cleaning demonstrations of 191 and 142 hours were performed

High-speed double-disc TMP [thermomechanical pulp] from northern and southern softwoods: One or two refining stages

Energy Technology Data Exchange (ETDEWEB)

Sabourin, M.J. (Andritz Sprout-Bauer, Inc., Springfield, OH (United States)); Cort, J.B.; Musselman, R.L. (Andritz Sprout-Bauer, Inc., Muncy, PA (United States))

1994-01-01

Pilot-plant studies were carried out to evaluate one- and two-stage high-speed refining processes for production of thermomechanical pulp (TMP) at minimal energy consumption. Both northern (black spruce/balsam fir) and southern (lobolly pine) wood species were tested. Preliminary results indicate both one- and two-stage high-speed refining are suitable for the production of TMP from spruce and fir. Single-stage, high-speed refining of spruce/fir resulted in over 25% energy savings compared to conventional TMP production. The resulting TMP had improved optical and shive content properties, with slightly reduced pulp strength and long fiber content. Two stages of refining were necessary to optimize pulp quality from the lobolly pine furnish. A 15% energy reduction was obtained when comparing high-speed and conventional TMP pulping of lobolly pine at similar operating conditions. The high-speed pine TMP had comparable bonding strength, shive content, and lower tear than conventional two-stage lobolly pine TMP. 14 refs., 11 figs., 6 tabs.

State and Local Clean Energy Policy Primer: Getting from Here to Clean Electricity with Policy (Fact Sheet)

Energy Technology Data Exchange (ETDEWEB)

2011-04-01

This fact sheet proposes a framework for how states and localities can build policy portfolios by first setting the stage for clean energy in the market with low cost policies, and then growing the market with successive policies until the need for financial incentives can be reduced and eventually eliminated.

Clean coal use in China: Challenges and policy implications

International Nuclear Information System (INIS)

Tang, Xu; Snowden, Simon; McLellan, Benjamin C.; Höök, Mikael

2015-01-01

Energy consumption in China is currently dominated by coal, a major source of air pollution and carbon emissions. The utilization of clean coal technologies is a likely strategic choice for China at present, however, although there have been many successes in clean coal technologies worldwide, they are not widely used in China. This paper examines the challenges that China faces in the implementation of such clean coal technologies, where the analysis shows that those drivers that have a negative bearing on the utilization of clean coal in China are mainly non-technical factors such as the low legal liability of atmospheric pollution related to coal use, and the lack of laws and mandatory regulations for clean coal use in China. Policies for the development of clean coal technologies are in their early stages in China, and the lack of laws and detailed implementation requirements for clean coal require resolution in order to accelerate China's clean coal developments. Currently, environmental pollution has gained widespread attention from the wider Chinese populace and taking advantage of this opportunity provides a space in which to regain the initiative to raise people’s awareness of clean coal products, and improve enterprises’ enthusiasm for clean coal. - Highlights: • Clean coal is not widely used in China due to many management issues. • Legal liability of pollution related with coal utilization is too low in China. • China is lack of laws and mandatory regulations for clean coal utilization. • It is difficult to accelerate clean coal utilization by incentive subsidies alone.

Cleaning of aluminum after machining with coolants

International Nuclear Information System (INIS)

Roop, B.

1992-01-01

An x-ray photoemission spectroscopic study was undertaken to compare the cleaning of the Advanced Photon Source (APS) aluminum extrusion storage ring vacuum chambers after machining with and without water soluble coolants. While there was significant contamination left by the coolants, the cleaning process was capable of removing the residue. The variation of the surface and near surface composition of samples machined either dry or with coolants was negligible after cleaning. The use of such coolants in the machining process is therefore recommended

Final Report on Two-Stage Fast Spectrum Fuel Cycle Options

International Nuclear Information System (INIS)

Yang, Won Sik; Lin, C. S.; Hader, J. S.; Park, T. K.; Deng, P.; Yang, G.; Jung, Y. S.; Kim, T. K.; Stauff, N. E.

2016-01-01

This report presents the performance characteristics of two ''two-stage'' fast spectrum fuel cycle options proposed to enhance uranium resource utilization and to reduce nuclear waste generation. One is a two-stage fast spectrum fuel cycle option of continuous recycle of plutonium (Pu) in a fast reactor (FR) and subsequent burning of minor actinides (MAs) in an accelerator-driven system (ADS). The first stage is a sodium-cooled FR fuel cycle starting with low-enriched uranium (LEU) fuel; at the equilibrium cycle, the FR is operated using the recovered Pu and natural uranium without supporting LEU. Pu and uranium (U) are co-extracted from the discharged fuel and recycled in the first stage, and the recovered MAs are sent to the second stage. The second stage is a sodium-cooled ADS in which MAs are burned in an inert matrix fuel form. The discharged fuel of ADS is reprocessed, and all the recovered heavy metals (HMs) are recycled into the ADS. The other is a two-stage FR/ADS fuel cycle option with MA targets loaded in the FR. The recovered MAs are not directly sent to ADS, but partially incinerated in the FR in order to reduce the amount of MAs to be sent to the ADS. This is a heterogeneous recycling option of transuranic (TRU) elements

Achieving Accurate Automatic Sleep Staging on Manually Pre-processed EEG Data Through Synchronization Feature Extraction and Graph Metrics.

Science.gov (United States)

Chriskos, Panteleimon; Frantzidis, Christos A; Gkivogkli, Polyxeni T; Bamidis, Panagiotis D; Kourtidou-Papadeli, Chrysoula

2018-01-01

Sleep staging, the process of assigning labels to epochs of sleep, depending on the stage of sleep they belong, is an arduous, time consuming and error prone process as the initial recordings are quite often polluted by noise from different sources. To properly analyze such data and extract clinical knowledge, noise components must be removed or alleviated. In this paper a pre-processing and subsequent sleep staging pipeline for the sleep analysis of electroencephalographic signals is described. Two novel methods of functional connectivity estimation (Synchronization Likelihood/SL and Relative Wavelet Entropy/RWE) are comparatively investigated for automatic sleep staging through manually pre-processed electroencephalographic recordings. A multi-step process that renders signals suitable for further analysis is initially described. Then, two methods that rely on extracting synchronization features from electroencephalographic recordings to achieve computerized sleep staging are proposed, based on bivariate features which provide a functional overview of the brain network, contrary to most proposed methods that rely on extracting univariate time and frequency features. Annotation of sleep epochs is achieved through the presented feature extraction methods by training classifiers, which are in turn able to accurately classify new epochs. Analysis of data from sleep experiments on a randomized, controlled bed-rest study, which was organized by the European Space Agency and was conducted in the "ENVIHAB" facility of the Institute of Aerospace Medicine at the German Aerospace Center (DLR) in Cologne, Germany attains high accuracy rates, over 90% based on ground truth that resulted from manual sleep staging by two experienced sleep experts. Therefore, it can be concluded that the above feature extraction methods are suitable for semi-automatic sleep staging.

Two-stage electrolysis to enrich tritium in environmental water

International Nuclear Information System (INIS)

Shima, Nagayoshi; Muranaka, Takeshi

2007-01-01

We present a two-stage electrolyzing procedure to enrich tritium in environmental waters. Tritium is first enriched rapidly through a commercially-available electrolyser with a large 50A current, and then through a newly-designed electrolyser that avoids the memory effect, with a 6A current. Tritium recovery factor obtained by such a two-stage electrolysis was greater than that obtained when using the commercially-available device solely. Water samples collected in 2006 in lakes and along the Pacific coast of Aomori prefecture, Japan, were electrolyzed using the two-stage method. Tritium concentrations in these samples ranged from 0.2 to 0.9 Bq/L and were half or less, that in samples collected at the same sites in 1992. (author)

HOSPITAL SITE SELECTION USING TWO-STAGE FUZZY MULTI-CRITERIA DECISION MAKING PROCESS

Directory of Open Access Journals (Sweden)

Ali Soltani

2011-06-01

Full Text Available Site selection for sitting of urban activities/facilities is one of the crucial policy-related decisions taken by urban planners and policy makers. The process of site selection is inherently complicated. A careless site imposes exorbitant costs on city budget and damages the environment inevitably. Nowadays, multi-attributes decision making approaches are suggested to use to improve precision of decision making and reduce surplus side effects. Two well-known techniques, analytical hierarchal process and analytical network process are among multi-criteria decision making systems which can easily be consistent with both quantitative and qualitative criteria. These are also developed to be fuzzy analytical hierarchal process and fuzzy analytical network process systems which are capable of accommodating inherent uncertainty and vagueness in multi-criteria decision-making. This paper reports the process and results of a hospital site selection within the Region 5 of Shiraz metropolitan area, Iran using integrated fuzzy analytical network process systems with Geographic Information System (GIS. The weights of the alternatives were calculated using fuzzy analytical network process. Then a sensitivity analysis was conducted to measure the elasticity of a decision in regards to different criteria. This study contributes to planning practice by suggesting a more comprehensive decision making tool for site selection.

HOSPITAL SITE SELECTION USING TWO-STAGE FUZZY MULTI-CRITERIA DECISION MAKING PROCESS

Directory of Open Access Journals (Sweden)

Ali Soltani

2011-01-01

Full Text Available Site selection for sitting of urban activities/facilities is one of the crucial policy-related decisions taken by urban planners and policy makers. The process of site selection is inherently complicated. A careless site imposes exorbitant costs on city budget and damages the environment inevitably. Nowadays, multi-attributes decision making approaches are suggested to use to improve precision of decision making and reduce surplus side effects. Two well-known techniques, analytical hierarchal process and analytical network process are among multi-criteria decision making systems which can easily be consistent with both quantitative and qualitative criteria. These are also developed to be fuzzy analytical hierarchal process and fuzzy analytical network process systems which are capable of accommodating inherent uncertainty and vagueness in multi-criteria decision-making. This paper reports the process and results of a hospital site selection within the Region 5 of Shiraz metropolitan area, Iran using integrated fuzzy analytical network process systems with Geographic Information System (GIS. The weights of the alternatives were calculated using fuzzy analytical network process. Then a sensitivity analysis was conducted to measure the elasticity of a decision in regards to different criteria. This study contributes to planning practice by suggesting a more comprehensive decision making tool for site selection.

Thermodynamics analysis of a modified dual-evaporator CO2 transcritical refrigeration cycle with two-stage ejector

International Nuclear Information System (INIS)

Bai, Tao; Yan, Gang; Yu, Jianlin

2015-01-01

In this paper, a modified dual-evaporator CO 2 transcritical refrigeration cycle with two-stage ejector (MDRC) is proposed. In MDRC, the two-stage ejector are employed to recover the expansion work from cycle throttling processes and enhance the system performance and obtain dual-temperature refrigeration simultaneously. The effects of some key parameters on the thermodynamic performance of the modified cycle are theoretically investigated based on energetic and exergetic analyses. The simulation results for the modified cycle show that two-stage ejector exhibits more effective system performance improvement than the single ejector in CO 2 dual-temperature refrigeration cycle, and the improvements of the maximum system COP (coefficient of performance) and system exergy efficiency could reach 37.61% and 31.9% over those of the conventional dual-evaporator cycle under the given operating conditions. The exergetic analysis for each component at optimum discharge pressure indicates that the gas cooler, compressor, two-stage ejector and expansion valves contribute main portion to the total system exergy destruction, and the exergy destruction caused by the two-stage ejector could amount to 16.91% of the exergy input. The performance characteristics of the proposed cycle show its promise in dual-evaporator refrigeration system. - Highlights: • Two-stage ejector is used in dual-evaporator CO 2 transcritical refrigeration cycle. • Energetic and exergetic methods are carried out to analyze the system performance. • The modified cycle could obtain dual-temperature refrigeration simultaneously. • Two-stage ejector could effectively improve system COP and exergy efficiency

Rudimentary Cleaning Compared to Level 300A

Science.gov (United States)

Arpin, Christina Y. Pina; Stoltzfus, Joel

2012-01-01

A study was done to characterize the cleanliness level achievable when using a rudimentary cleaning process, and results were compared to JPR 5322.1G Level 300A. While it is not ideal to clean in a shop environment, some situations (e.g., field combat operations) require oxygen system hardware to be maintained and cleaned to prevent a fire hazard, even though it cannot be sent back to a precision cleaning facility. This study measured the effectiveness of basic shop cleaning. Initially, three items representing parts of an oxygen system were contaminated: a metal plate, valve body, and metal oxygen bottle. The contaminants chosen were those most likely to be introduced to the system during normal use: oil, lubricant, metal shavings/powder, sand, fingerprints, tape, lip balm, and hand lotion. The cleaning process used hot water, soap, various brushes, gaseous nitrogen, water nozzle, plastic trays, scouring pads, and a controlled shop environment. Test subjects were classified into three groups: technical professionals having an appreciation for oxygen hazards; professional precision cleaners; and a group with no previous professional knowledge of oxygen or precision cleaning. Three test subjects were in each group, and each was provided with standard cleaning equipment, a cleaning procedure, and one of each of the three test items to clean. The results indicated that the achievable cleanliness level was independent of the technical knowledge or proficiency of the personnel cleaning the items. Results also showed that achieving a Level 300 particle count was more difficult than achieving a Level A nonvolatile residue amount.

Habitat Fragmentation Drives Plant Community Assembly Processes across Life Stages

Science.gov (United States)

Hu, Guang; Feeley, Kenneth J.; Yu, Mingjian

2016-01-01

Habitat fragmentation is one of the principal causes of biodiversity loss and hence understanding its impacts on community assembly and disassembly is an important topic in ecology. We studied the relationships between fragmentation and community assembly processes in the land-bridge island system of Thousand Island Lake in East China. We focused on the changes in species diversity and phylogenetic diversity that occurred between life stages of woody plants growing on these islands. The observed diversities were compared with the expected diversities from random null models to characterize assembly processes. Regression tree analysis was used to illustrate the relationships between island attributes and community assembly processes. We found that different assembly processes predominate in the seedlings-to-saplings life-stage transition (SS) vs. the saplings-to-trees transition (ST). Island area was the main attribute driving the assembly process in SS. In ST, island isolation was more important. Within a fragmented landscape, the factors driving community assembly processes were found to differ between life stage transitions. Environmental filtering had a strong effect on the seedlings-to-saplings life-stage transition. Habitat isolation and dispersal limitation influenced all plant life stages, but had a weaker effect on communities than area. These findings add to our understanding of the processes driving community assembly and species coexistence in the context of pervasive and widespread habitat loss and fragmentation. PMID:27427960

A two-stage planning and control model toward Economically Adapted Power Distribution Systems using analytical hierarchy processes and fuzzy optimization

Energy Technology Data Exchange (ETDEWEB)

Schweickardt, Gustavo [Instituto de Economia Energetica, Fundacion Bariloche, Centro Atomico Bariloche - Pabellon 7, Av. Bustillo km 9500, 8400 Bariloche (Argentina); Miranda, Vladimiro [INESC Porto, Instituto de Engenharia de Sistemas e Computadores do Porto and FEUP, Faculdade de Engenharia da Universidade do Porto, R. Dr. Roberto Frias, 378, 4200-465 Porto (Portugal)

2009-07-15

This work presents a model to evaluate the Distribution System Dynamic De-adaptation respecting its planning for a given period of Tariff Control. The starting point for modeling is brought about by the results from a multi-criteria method based on Fuzzy Dynamic Programming and on Analytic Hierarchy Processes applied in a mid/short-term horizon (stage 1). Then, the decision-making activities using the Hierarchy Analytical Processes will allow defining, for a Control of System De-adaptation (stage 2), a Vector to evaluate the System Dynamic Adaptation. It is directly associated to an eventual series of inbalances that take place during its evolution. (author)

On A Two-Stage Supply Chain Model In The Manufacturing Industry ...

African Journals Online (AJOL)

We model a two-stage supply chain where the upstream stage (stage 2) always meet demand from the downstream stage (stage 1).Demand is stochastic hence shortages will occasionally occur at stage 2. Stage 2 must fill these shortages by expediting using overtime production and/or backordering. We derive optimal ...

Clean Technology Evaluation & Workforce Development Program

Energy Technology Data Exchange (ETDEWEB)

Patricia Glaza

2012-12-01

The overall objective of the Clean Technology Evaluation portion of the award was to design a process to speed up the identification of new clean energy technologies and match organizations to testing and early adoption partners. The project was successful in identifying new technologies targeted to utilities and utility technology integrators, in developing a process to review and rank the new technologies, and in facilitating new partnerships for technology testing and adoption. The purpose of the Workforce Development portion of the award was to create an education outreach program for middle & high-school students focused on clean technology science and engineering. While originally targeting San Diego, California and Cambridge, Massachusetts, the scope of the program was expanded to include a major clean technology speaking series and expo as part of the USA Science & Engineering Festival on the National Mall in Washington, D.C.

Optimization of a two stage process for biodiesel production from shea butter using response surface methodology

Directory of Open Access Journals (Sweden)

E.O. Ajala

2017-12-01

Full Text Available The challenges of biodiesel production from high free fatty acid (FFA shea butter (SB necessitated this study. The reduction of %FFA of SB by esterification and its subsequent utilization by transesterification for biodiesel production in a two stage process for optimization studies was investigated using response surface methodology based on a central composite design (CCD. Four operating conditions were investigated to reduce the %FFA of SB and increase the %yield of shea biodiesel (SBD. The operating conditions were temperature (40–60°C, agitation speed (200–1400 rpm, methanol (MeOH: oil mole ratio: 2:1–6:1 (w/w for esterification and 4:1–8:1 (w/w for transesterification and catalyst loading: 1–2% (H2SO4, (v/v for esterification and KOH, (w/w for transesterification. The significance of the parameters obtained in linear and non-linear form from the models were determined using analysis of variance (ANOVA. The optimal operating conditions that gave minimum FFA of 0.26% were 52.19°C, 200 rpm, 2:1 (w/w and 1.5% (v/v, while those that gave maximum yield of 92.16% SBD were 40°C, 800 rpm, 7:1 (w/w and 1% (w/w. The p-value of <0.0001 for each of the stages showed that the models were significant with R2 of 0.96 each. These results indicate the reproducibility of the models and showed that the RSM is suitable to optimize the esterification and transesterification of SB for SBD production. Therefore, RSM is a useful tool that can be employed in industrial scale production of SBD from high FFA SB.

Correlating Cleaning Thoroughness with Effectiveness and Briefly Intervening to Affect Cleaning Outcomes: How Clean Is Cleaned?

Directory of Open Access Journals (Sweden)

Robert Clifford

Full Text Available The most efficient approach to monitoring and improving cleaning outcomes remains unresolved. We sought to extend the findings of a previous study by determining whether cleaning thoroughness (dye removal correlates with cleaning efficacy (absence of molecular or cultivable biomaterial and whether one brief educational intervention improves cleaning outcomes.Before-after trial.Newly built community hospital.90 minute training refresher with surface-specific performance results.Dye removal, measured by fluorescence, and biomaterial removal and acquisition, measured with culture and culture-independent PCR-based assays, were clandestinely assessed for eight consecutive months. At this midpoint, results were presented to the cleaning staff (intervention and assessments continued for another eight consecutive months.1273 surfaces were sampled before and after terminal room cleaning. In the short-term, dye removal increased from 40.3% to 50.0% (not significant. For the entire study period, dye removal also improved but not significantly. After the intervention, the number of rooms testing positive for specific pathogenic species by culturing decreased from 55.6% to 36.6% (not significant, and those testing positive by PCR fell from 80.6% to 53.7% (P = 0.016. For nonspecific biomaterial on surfaces: a removal of cultivable Gram-negatives (GN trended toward improvement (P = 0.056; b removal of any cultivable growth was unchanged but acquisition (detection of biomaterial on post-cleaned surfaces that were contaminant-free before cleaning worsened (P = 0.017; c removal of PCR-based detection of bacterial DNA improved (P = 0.046, but acquisition worsened (P = 0.003; d cleaning thoroughness and efficacy were not correlated.At this facility, a minor intervention or minimally more aggressive cleaning may reduce pathogen-specific contamination, but not without unintended consequences.

A Facile in Situ and UV Printing Process for Bioinspired Self-Cleaning Surfaces

Directory of Open Access Journals (Sweden)

Marina A. González Lazo

2016-08-01

Full Text Available A facile in situ and UV printing process was demonstrated to create self-cleaning synthetic replica of natural petals and leaves. The process relied on the spontaneous migration of a fluorinated acrylate surfactant (PFUA within a low-shrinkage acrylated hyperbranched polymer (HBP and its chemical immobilization at the polymer-air interface. Dilute concentrations of 1 wt. % PFUA saturated the polymer-air interface within 30 min, leading to a ten-fold increase of fluorine concentration at the surface compared with the initial bulk concentration and a water contact angle (WCA of 108°. A 200 ms flash of UV light was used to chemically crosslink the PFUA at the HBP surface prior to UV printing with a polydimethylsiloxane (PDMS negative template of red and yellow rose petals and lotus leaves. This flash immobilization hindered the reverse migration of PFUA within the bulk HBP upon contacting the PDMS template, and enabled to produce texturized surfaces with WCA well above 108°. The synthetic red rose petal was hydrophobic (WCA of 125° and exhibited the adhesive petal effect. It was not superhydrophobic due to insufficient concentration of fluorine at its surface, a result of the very large increase of the surface of the printed texture. The synthetic yellow rose petal was quasi-superhydrophobic (WCA of 143°, roll-off angle of 10° and its self-cleaning ability was not good also due to lack of fluorine. The synthetic lotus leaf did not accurately replicate the intricate nanotubular crystal structures of the plant. In spite of this, the fluorine concentration at the surface was high enough and the leaf was superhydrophobic (WCA of 151°, roll-off angle below 5° and also featured self-cleaning properties.

Hydrodynamic design of an underwater hull cleaning robot and its evaluation

Directory of Open Access Journals (Sweden)

Man Hyung Lee

2012-12-01

Full Text Available An underwater hull cleaning robot can be a desirable choice for the cleaning of large ships. It can make the cleaning process safe and economical. This paper presents a hydrodynamic design of an underwater cleaning robot and its evaluation for an underwater ship hull cleaning robot. The hydrodynamic design process of the robot body is described in detail. Optimal body design process with compromises among conflicting design requirements is given. Experimental results on the hydrodynamic performance of the robot are given.

Rapid Two-stage Versus One-stage Surgical Repair of Interrupted Aortic Arch with Ventricular Septal Defect in Neonates

Directory of Open Access Journals (Sweden)

Meng-Lin Lee

2008-11-01

Conclusion: The outcome of rapid two-stage repair is comparable to that of one-stage repair. Rapid two-stage repair has the advantages of significantly shorter cardiopulmonary bypass duration and AXC time, and avoids deep hypothermic circulatory arrest. LVOTO remains an unresolved issue, and postoperative aortic arch restenosis can be dilated effectively by percutaneous balloon angioplasty.

Emerging forward osmosis (FO) technologies and challenges ahead for clean water and clean energy applications

KAUST Repository

Chung, Tai-Shung; Li, Xue; Ong, Rui Chin; Ge, Qingchun; Wang, Honglei; Han, Gang

2012-01-01

The purpose of this short review is to share our understanding and perspectives with the chemical, environmental, water and osmotic power communities on FO processes in order to conduct meaningful R & D and develop effective and sustainable FO technologies for clean water and clean energy. © 2012 Elsevier Ltd. All rights reserved.

Emerging forward osmosis (FO) technologies and challenges ahead for clean water and clean energy applications

KAUST Repository

Chung, Tai-Shung

2012-08-01

The purpose of this short review is to share our understanding and perspectives with the chemical, environmental, water and osmotic power communities on FO processes in order to conduct meaningful R & D and develop effective and sustainable FO technologies for clean water and clean energy. © 2012 Elsevier Ltd. All rights reserved.

Teaching basic life support with an automated external defibrillator using the two-stage or the four-stage teaching technique.

Science.gov (United States)

Bjørnshave, Katrine; Krogh, Lise Q; Hansen, Svend B; Nebsbjerg, Mette A; Thim, Troels; Løfgren, Bo

2018-02-01

Laypersons often hesitate to perform basic life support (BLS) and use an automated external defibrillator (AED) because of self-perceived lack of knowledge and skills. Training may reduce the barrier to intervene. Reduced training time and costs may allow training of more laypersons. The aim of this study was to compare BLS/AED skills' acquisition and self-evaluated BLS/AED skills after instructor-led training with a two-stage versus a four-stage teaching technique. Laypersons were randomized to either two-stage or four-stage teaching technique courses. Immediately after training, the participants were tested in a simulated cardiac arrest scenario to assess their BLS/AED skills. Skills were assessed using the European Resuscitation Council BLS/AED assessment form. The primary endpoint was passing the test (17 of 17 skills adequately performed). A prespecified noninferiority margin of 20% was used. The two-stage teaching technique (n=72, pass rate 57%) was noninferior to the four-stage technique (n=70, pass rate 59%), with a difference in pass rates of -2%; 95% confidence interval: -18 to 15%. Neither were there significant differences between the two-stage and four-stage groups in the chest compression rate (114±12 vs. 115±14/min), chest compression depth (47±9 vs. 48±9 mm) and number of sufficient rescue breaths between compression cycles (1.7±0.5 vs. 1.6±0.7). In both groups, all participants believed that their training had improved their skills. Teaching laypersons BLS/AED using the two-stage teaching technique was noninferior to the four-stage teaching technique, although the pass rate was -2% (95% confidence interval: -18 to 15%) lower with the two-stage teaching technique.

Clean Cast Steel Technology - Machinability and Technology Transfer

Energy Technology Data Exchange (ETDEWEB)

C. E. Bates; J. A. Griffin

2000-05-01

There were two main tasks in the Clean Cast Steel Technology - Machinability and Technology Transfer Project. These were (1) determine the processing facts that control the machinability of cast steel and (2) determine the ability of ladle stirring to homogenize ladle temperature, reduce the tap and pouring temperatures, and reduce casting scrap.

Self Cleaning High Efficiency Particulate Air (HEPA) Filtration without Interrupting Process Flow - 59347

International Nuclear Information System (INIS)

Chadwick, Chris

2012-01-01

The strategy of protecting the traditional glass fibre HEPA filtration train from it's blinding contamination and the recovery of dust by the means of self cleaning, pre-filtration is a proven means in the reduction of ultimate disposal volumes and has been used within the Fuel Production Industry. However, there is an increasing demand in nuclear applications requiring elevated operating temperatures, fire resistance, moisture resistance and chemical composition that the existing glass fibre HEPA filtration cannot accommodate, which can be remedied by the use of a metallic HEPA filter media. Previous research suggests that the then costs to the Department of Energy (DOE), based on a five year life cycle, was $29.5 million for the installation, testing, removal and disposal of glass fibre HEPA filtration trains. Within these costs, $300 was the value given to the filter and $4, 450 was given to the peripheral activity. Development of a low cost, cleanable, metallic, direct replacement of the traditional filter train will the clear solution. The Bergman et al work has suggested that a 1000 ft 3 /min, cleanable, stainless HEPA could be commercially available for $5, 000 each, whereas the industry has determined that the truer cost of such an item in isolation would be closer to $15, 000. This results in a conflict within the requirement between 'low cost' and 'stainless HEPA'. By proposing a system that combines metallic HEPA filtration with the ability to self clean without interrupting the process flow, the need for a tradition HEPA filtration train will be eliminated and this dramatically reduces the resources required for cleaning or disposal, thus presenting a route to reducing ultimate costs. The paper will examine the performance characteristics, filtration efficiency, flow verses differential pressure and cleanability of a self cleaning HEPA grade sintered metal filter element, together with data to prove the contention. (authors)

Staged fluidized-bed coal combustor for boiler retrofit

International Nuclear Information System (INIS)

Rehmat, A.; Dorfman, L.; Shibayama, G.; Waibel, R.

1991-01-01

The Advanced Staged Fluidized-Bed Coal Combustion System (ASC) is a novel clean coal technology for either coal-fired repowering of existing boilers or for incremental power generation using combined-cycle gas turbines. This new technology combines staged combustion for gaseous emission control, in-situ sulfur capture, and an ash agglomeration/vitrification process for the agglomeration/vitrification of ash and spent sorbent, thus rendering solid waste environmentally benign. The market for ASC is expected to be for clean coal-fired repowering of generating units up to 250 MW, especially for units where space is limited. The expected tightening of the environmental requirements on leachable solids residue by-products could considerably increase the marketability for ASC. ASC consists of modular low-pressure vessels in which coal is partially combusted and gasified using stacked fluidized-bed processes to produce low-to-medium-Btu, high-temperature gas. This relatively clean fuel gas is used to repower/refuel existing pulverized-coal, natural gas, or oil-fired boilers using bottom firing and reburning techniques. The benefits of ASC coal-fired repowering include the ability to repower boilers without obtaining additional space while meeting the more stringent environmental requirements of the future. Low NO x , SO x , and particulate levels are expected while a nonleachable solid residue with trace metal encapsulation is produced. ASC also minimizes boiler modification and life-extension expenditures. Repowered efficiencies can be restored to the initial operating plant efficiency, and the existing boiler capacity can be increased by 10%. Preliminary cost estimates indicate that ASC will have up to a $250/kW capital cost advantage over existing coal-fired repowering options. 4 figs., 4 tabs

A Two-Stage Queue Model to Optimize Layout of Urban Drainage System considering Extreme Rainstorms

OpenAIRE

He, Xinhua; Hu, Wenfa

2017-01-01

Extreme rainstorm is a main factor to cause urban floods when urban drainage system cannot discharge stormwater successfully. This paper investigates distribution feature of rainstorms and draining process of urban drainage systems and uses a two-stage single-counter queue method M/M/1→M/D/1 to model urban drainage system. The model emphasizes randomness of extreme rainstorms, fuzziness of draining process, and construction and operation cost of drainage system. Its two objectives are total c...

Fire protection for clean rooms

International Nuclear Information System (INIS)

Kirson, D.

1990-01-01

The fire protection engineer often must decide what size fire can be tolerated before automatic fire suppression systems actuate. Is it a wastepaper basket fire, a bushel basket fire...? In the case of state-of-the-art clean rooms, the answer clearly is not even an incipient fire. Minor fires in clean rooms can cause major losses. This paper discusses what a clean room is and gives a brief overview of the unique fire protection challenges encountered. The two major causes of fire related to clean rooms in the semiconductor industry are flammable/pyrophoric gas fires in plastic ducts and polypropylene wet bench fires. This paper concentrates on plastic ductwork in clean rooms, sprinkler protection in ductwork, and protection for wet benches

Late Financial Distress Process Stages and Financial Ratios

DEFF Research Database (Denmark)

Sormunen, Nina; Laitinen, Teija

2012-01-01

stage affects the classification ability of single financial ratios and financial distress prediction models in short-term financial distress prediction. The study shows that the auditor's GC task could be supported by paying attention to the financial distress process stage. The implications...... of these findings for auditors and every stakeholder of business firms are considered....

Final Report on Two-Stage Fast Spectrum Fuel Cycle Options

Energy Technology Data Exchange (ETDEWEB)

Yang, Won Sik [Purdue Univ., West Lafayette, IN (United States); Lin, C. S. [Purdue Univ., West Lafayette, IN (United States); Hader, J. S. [Purdue Univ., West Lafayette, IN (United States); Park, T. K. [Purdue Univ., West Lafayette, IN (United States); Deng, P. [Purdue Univ., West Lafayette, IN (United States); Yang, G. [Purdue Univ., West Lafayette, IN (United States); Jung, Y. S. [Purdue Univ., West Lafayette, IN (United States); Kim, T. K. [Argonne National Lab. (ANL), Argonne, IL (United States); Stauff, N. E. [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-01-30

This report presents the performance characteristics of two “two-stage” fast spectrum fuel cycle options proposed to enhance uranium resource utilization and to reduce nuclear waste generation. One is a two-stage fast spectrum fuel cycle option of continuous recycle of plutonium (Pu) in a fast reactor (FR) and subsequent burning of minor actinides (MAs) in an accelerator-driven system (ADS). The first stage is a sodium-cooled FR fuel cycle starting with low-enriched uranium (LEU) fuel; at the equilibrium cycle, the FR is operated using the recovered Pu and natural uranium without supporting LEU. Pu and uranium (U) are co-extracted from the discharged fuel and recycled in the first stage, and the recovered MAs are sent to the second stage. The second stage is a sodium-cooled ADS in which MAs are burned in an inert matrix fuel form. The discharged fuel of ADS is reprocessed, and all the recovered heavy metals (HMs) are recycled into the ADS. The other is a two-stage FR/ADS fuel cycle option with MA targets loaded in the FR. The recovered MAs are not directly sent to ADS, but partially incinerated in the FR in order to reduce the amount of MAs to be sent to the ADS. This is a heterogeneous recycling option of transuranic (TRU) elements

Engineering development of advanced physical fine coal cleaning for premium fuel applications

International Nuclear Information System (INIS)

1997-01-01

Bechtel, together with Amax Research and Development Center (Amax R ampersand D), has prepared this study which provides conceptual cost estimates for the production of premium quality coal-water slurry fuel (CWF) in a commercial plant. Two scenarios are presented, one using column flotation technology and the other the selective agglomeration to clean the coal to the required quality specifications. This study forms part of US Department of Energy program Engineering Development of Advanced Physical Fine Coal Cleaning for Premium Fuel Applications, (Contract No. DE-AC22- 92PC92208), under Task 11, Project Final Report. The primary objective of the Department of Energy program is to develop the design base for prototype commercial advanced fine coal cleaning facilities capable of producing ultra-clean coals suitable for conversion to stable and highly loaded CWF. The fuels should contain less than 2 lb ash/MBtu (860 grams ash/GJ) of HHV and preferably less than 1 lb ash/MBtu (430 grams ash/GJ). The advanced fine coal cleaning technologies to be employed are advanced column froth flotation and selective agglomeration. It is further stipulated that operating conditions during the advanced cleaning process should recover not less than 80 percent of the carbon content (heating value) in the run-of-mine source coal. These goals for ultra-clean coal quality are to be met under the constraint that annualized coal production costs does not exceed $2.5 /MBtu ($ 2.37/GJ), including the mine mouth cost of the raw coal. A further objective of the program is to determine the distribution of a selected suite of eleven toxic trace elements between product CWF and the refuse stream of the cleaning processes. Laboratory, bench-scale and Process Development Unit (PDU) tests to evaluate advanced column flotation and selective agglomeration were completed earlier under this program with selected coal samples. A PDU with a capacity of 2 st/h was designed by Bechtel and installed at

Clean fuel technologies and clean and reliable energy: a summary

International Nuclear Information System (INIS)

Bulatov, Igor; Klemes, Jiri Jaromir

2011-01-01

There are two major areas covered by this current Special Issue: Cleaner Fuel Technologies and Waste Processing. In addition, the Special Issue, also includes some recent developments in various fields of energy efficiency research. The first group of contributions considers in detail, hydrogen production from biomass and hydrogen production by the sorption-enhanced steam methane reforming process (SE-SMR). Biomass-related technologies are also discussed for a design of an integrated biorefinery, production of clean diesel fuel by co-hydrogenation of vegetable oil with gas oil and utilization of microwave and ultrasound pretreatments in the production of bioethanol from corn. Waste Processing aspects are considered in the second group of papers. This section includes integrated waste-to-energy plants, utilisation of municipal solid waste in the cement industry and urban supply and disposal systems. The third topic is intentionally made rather loose: it includes different research topics on various aspects of energy efficiency, e.g. resource-saving network design, new research on divided wall columns, vehicle logistics as process-network synthesis for energy consumption and CO 2 reduction.

Preliminary technical data summary defense waste processing facility stage 2

International Nuclear Information System (INIS)

1980-12-01

This Preliminary Technical Data Summary presents the technical basis for design of Stage 2 of the Staged Defense Waste Processing Facility (DWPF). Process changes incorporated in the staged DWPF relative to the Alternative DWPF described in PTDS No. 3 (DPSTD-77-13-3) are the result of ongoing research and development and are aimed at reducing initial capital investment and developing a process to efficiently immobilize the radionuclides in Savannah River Plant (SRP) high-level liquid waste. The radionuclides in SRP waste are present in sludge that has settled to the bottom of waste storage tanks and in crystallized salt and salt solution (supernate). Stage 1 of the DWPF receives washed, aluminum dissolved sludge from the waste tank farms and immobilizes it in a borosilicate glass matrix. The supernate is retained in the waste tank farms until completion of Stage 2 of the DWPF at which time it is filtered and decontaminated by ion exchange in the Stage 2 facility. The decontaminated supernate is concentrated by evaporation and mixed with cement for burial. The radioactivity removed from the supernate is fixed in borosilicate glass along with the sludge. This document gives flowsheets, material and curie balances, material and curie balance bases, and other technical data for design of Stage 2 of the DWPF. Stage 1 technical data are presented in DPSTD-80-38

Runway Operations Planning: A Two-Stage Heuristic Algorithm

Science.gov (United States)

Anagnostakis, Ioannis; Clarke, John-Paul

2003-01-01

The airport runway is a scarce resource that must be shared by different runway operations (arrivals, departures and runway crossings). Given the possible sequences of runway events, careful Runway Operations Planning (ROP) is required if runway utilization is to be maximized. From the perspective of departures, ROP solutions are aircraft departure schedules developed by optimally allocating runway time for departures given the time required for arrivals and crossings. In addition to the obvious objective of maximizing throughput, other objectives, such as guaranteeing fairness and minimizing environmental impact, can also be incorporated into the ROP solution subject to constraints introduced by Air Traffic Control (ATC) procedures. This paper introduces a two stage heuristic algorithm for solving the Runway Operations Planning (ROP) problem. In the first stage, sequences of departure class slots and runway crossings slots are generated and ranked based on departure runway throughput under stochastic conditions. In the second stage, the departure class slots are populated with specific flights from the pool of available aircraft, by solving an integer program with a Branch & Bound algorithm implementation. Preliminary results from this implementation of the two-stage algorithm on real-world traffic data are presented.

Energy production from agricultural residues: High methane yields in pilot-scale two-stage anaerobic digestion

International Nuclear Information System (INIS)

Parawira, W.; Read, J.S.; Mattiasson, B.; Bjoernsson, L.

2008-01-01

There is a large, unutilised energy potential in agricultural waste fractions. In this pilot-scale study, the efficiency of a simple two-stage anaerobic digestion process was investigated for stabilisation and biomethanation of solid potato waste and sugar beet leaves, both separately and in co-digestion. A good phase separation between hydrolysis/acidification and methanogenesis was achieved, as indicated by the high carbon dioxide production, high volatile fatty acid concentration and low pH in the acidogenic reactors. Digestion of the individual substrates gave gross energy yields of 2.1-3.4 kWh/kg VS in the form of methane. Co-digestion, however, gave up to 60% higher methane yield, indicating that co-digestion resulted in improved methane production due to the positive synergism established in the digestion liquor. The integrity of the methane filters (MFs) was maintained throughout the period of operation, producing biogas with 60-78% methane content. A stable effluent pH showed that the methanogenic reactors had good ability to withstand the variations in load and volatile fatty acid concentrations that occurred in the two-stage process. The results of this pilot-scale study show that the two-stage anaerobic digestion system is suitable for effective conversion of semi-solid agricultural residues as potato waste and sugar beet leaves

Cleaning and Processing RSS measurements for Location Fingerprinting

DEFF Research Database (Denmark)

Kjærgaard, Mikkel Baun

2007-01-01

Handling variations in sampled Received Signal Strength (RSS) is neassary for achieving robust location fingerprinting (LF). Current research has only proposed limited system-specific models for how to handle the cleaning of RSS variations. However, this paper propose a novel model for both...

Nanometer-scale lithography on microscopically clean graphene

International Nuclear Information System (INIS)

Van Dorp, W F; De Hosson, J Th M; Zhang, X; Feringa, B L; Wagner, J B; Hansen, T W

2011-01-01

Focused-electron-beam-induced deposition, or FEBID, enables the fabrication of patterns with sub-10 nm resolution. The initial stages of metal deposition by FEBID are still not fundamentally well understood. For these investigations, graphene, a one-atom-thick sheet of carbon atoms in a hexagonal lattice, is ideal as the substrate for FEBID writing. In this paper, we have used exfoliated few-layer graphene as a support to study the early growth phase of focused-electron-beam-induced deposition and to write patterns with dimensions between 0.6 and 5 nm. The results obtained here are compared to the deposition behavior on amorphous materials. Prior to the deposition experiment, the few-layer graphene was cleaned. Typically, it is observed in electron microscope images that areas of microscopically clean graphene are surrounded by areas with amorphous material. We present a method to remove the amorphous material in order to obtain large areas of microscopically clean graphene flakes. After cleaning, W(CO) 6 was used as the precursor to study the early growth phase of FEBID deposits. It was observed that preferential adsorption of the precursor molecules on step edges and adsorbates plays a key role in the deposition on cleaned few-layer graphene.

Two stage, low temperature, catalyzed fluidized bed incineration with in situ neutralization for radioactive mixed wastes

International Nuclear Information System (INIS)

Wade, J.F.; Williams, P.M.

1995-01-01

A two stage, low temperature, catalyzed fluidized bed incineration process is proving successful at incinerating hazardous wastes containing nuclear material. The process operates at 550 degrees C and 650 degrees C in its two stages. Acid gas neutralization takes place in situ using sodium carbonate as a sorbent in the first stage bed. The feed material to the incinerator is hazardous waste-as defined by the Resource Conservation and Recovery Act-mixed with radioactive materials. The radioactive materials are plutonium, uranium, and americium that are byproducts of nuclear weapons production. Despite its low temperature operation, this system successfully destroyed poly-chlorinated biphenyls at a 99.99992% destruction and removal efficiency. Radionuclides and volatile heavy metals leave the fluidized beds and enter the air pollution control system in minimal amounts. Recently collected modeling and experimental data show the process minimizes dioxin and furan production. The report also discusses air pollution, ash solidification, and other data collected from pilot- and demonstration-scale testing. The testing took place at Rocky Flats Environmental Technology Site, a US Department of Energy facility, in the 1970s, 1980s, and 1990s

Two-stage residual inclusion estimation: addressing endogeneity in health econometric modeling.

Science.gov (United States)

Terza, Joseph V; Basu, Anirban; Rathouz, Paul J

2008-05-01

The paper focuses on two estimation methods that have been widely used to address endogeneity in empirical research in health economics and health services research-two-stage predictor substitution (2SPS) and two-stage residual inclusion (2SRI). 2SPS is the rote extension (to nonlinear models) of the popular linear two-stage least squares estimator. The 2SRI estimator is similar except that in the second-stage regression, the endogenous variables are not replaced by first-stage predictors. Instead, first-stage residuals are included as additional regressors. In a generic parametric framework, we show that 2SRI is consistent and 2SPS is not. Results from a simulation study and an illustrative example also recommend against 2SPS and favor 2SRI. Our findings are important given that there are many prominent examples of the application of inconsistent 2SPS in the recent literature. This study can be used as a guide by future researchers in health economics who are confronted with endogeneity in their empirical work.

Clean-room robot implementation

International Nuclear Information System (INIS)

Comeau, J.L.

1982-01-01

A robot has been incorporated in a clean room operation in which vacuum tube parts are cleaned just prior to final assembly with a 60 lb/in 2 blast of argon gas. The robot is programmed to pick up the parts, manipulate/rotate them as necessary in the jet pattern and deposit them in a tray precleaned by the robot. A carefully studied implementation plan was followed in the procurement, installation, modification and programming of the robot facility. An unusual configuration of one tube part required a unique gripper design. A study indicated that the tube parts processed by the robot are 12% cleaner than those manually cleaned by an experienced operator

Incidence and properties of Staphylococcus aureus associated with turkeys during processing and further-processing operations.

Science.gov (United States)

Adams, B W; Mead, G C

1983-12-01

The incidence of Staphylococcus aureus on turkeys sampled at various stages of processing and further-processing was determined on four occasions at each of three different processing plants. For freshly-slaughtered birds, counts from neck skin varied from plant to plant over the range less than 10(2) to greater than 10(5)/g but in all cases the corresponding counts obtained from carcasses sampled after chilling rarely exceeded 10(3)/g and the same was true for samples of mechanically recovered meat (MRM), the final raw product examined. Despite the limited susceptibility of isolates from the different factories to typing by means of either standard human or poultry bacteriophages (55-94% untypable), evidence was obtained with the aid of biotyping for the presence of both human and animal-derived strains. However, some biotypes isolated from MRM were not detected at earlier stages of processing. At one processing plant, an "indigenous' type of S. aureus was clearly demonstrated. It occurred in high numbers in the defeathering machines (up to 10(5)/swab), was found on carcasses at all subsequent stages of processing over the survey period and was shown to survive routine cleaning and disinfection procedures. Isolates of this type produced unusually large amounts of extracellular "slime' in artificial culture. Two of the three processing plants yielded isolates which were enterotoxigenic. Of 55 strains from Plant 1, 60% produced enterotoxin C and all were of the "indigenous' type. In the case of Plant 2, only two type D- and one type F-producing strain were found.

Maximally efficient two-stage screening: Determining intellectual disability in Taiwanese military conscripts.

Science.gov (United States)

Chien, Chia-Chang; Huang, Shu-Fen; Lung, For-Wey

2009-01-27

The purpose of this study was to apply a two-stage screening method for the large-scale intelligence screening of military conscripts. We collected 99 conscripted soldiers whose educational levels were senior high school level or lower to be the participants. Every participant was required to take the Wisconsin Card Sorting Test (WCST) and the Wechsler Adult Intelligence Scale-Revised (WAIS-R) assessments. Logistic regression analysis showed the conceptual level responses (CLR) index of the WCST was the most significant index for determining intellectual disability (ID; FIQ ≤ 84). We used the receiver operating characteristic curve to determine the optimum cut-off point of CLR. The optimum one cut-off point of CLR was 66; the two cut-off points were 49 and 66. Comparing the two-stage window screening with the two-stage positive screening, the area under the curve and the positive predictive value increased. Moreover, the cost of the two-stage window screening decreased by 59%. The two-stage window screening is more accurate and economical than the two-stage positive screening. Our results provide an example for the use of two-stage screening and the possibility of the WCST to replace WAIS-R in large-scale screenings for ID in the future.

Frequency of hepatitis E virus, rotavirus and porcine enteric calicivirus at various stages of pork carcass processing in two pork processing plants.

Science.gov (United States)

Jones, Tineke H; Muehlhauser, Victoria

2017-10-16

Hepatitis E virus (HEV), rotavirus (RV), and porcine enteric calicivirus (PEC) infections are common in swine and raises concerns about the potential for zoonotic transmission through undercooked meat products. Enteric viruses can potentially contaminate carcasses during meat processing operations. There is a lack of information on the prevalence and control of enteric viruses in the pork processing chain. This study compared the incidence and levels of contamination of hog carcasses with HEV, RV and PEC at different stages of the dressing process. A total of 1000 swabs were collected from 2 pork processing plants on 10 separate occasions over the span of a year. The samples were obtained from random sites on hog carcasses at 4 dressing stages (plant A: bleeding, dehairing, pasteurization, and evisceration; plant B: bleeding, skinning, evisceration, and washing) and from meat cuts. Numbers of genome copies (gc) of HEV, RV and PEC were determined by RT-qPCR. RV and PEC were detected in 100%, and 18% of samples, respectively, after bleeding for plant A and in 98%, and 36% of samples, respectively, after bleeding for plant B. After evisceration, RV and PEC were detected in 21% and 3% of samples, respectively, for plant A and in 1%, and 0% of samples, respectively for plant B. RV and PEC were detected on 1%, and 5% of pork cuts, respectively, for plant A and on 0%, and 0% of pork cuts, respectively, for plant B. HEV was not detected in any pork carcass or retail pork samples from plants A or B. The frequency of PEC and RV on pork is progressively reduced along the pork processing chain but the viruses were not completely eliminated. The findings suggest that consumers could be at risk when consuming undercooked meat contaminated with pathogenic enteric viruses. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Tooth cleaning frequency in relation to socio-demographic variables and personal hygiene measures among school children of Udaipur district, India.

Science.gov (United States)

Kumar, S; Panwar, J; Vyas, A; Sharma, J; Goutham, B; Duraiswamy, P; Kulkarni, S

2011-02-01

The aim of the study was to determine if frequency of tooth cleaning varies with social group, family size, bedtime and other personal hygiene habits among school children. Target population comprised schoolchildren aged 8-16 years of Udaipur district attending public schools. A two stage cluster random sampling procedure was executed to collect the representative sample, consequently final sample size accounted to 852 children. Data were collected by means of structured questionnaires which consisted of questions related to oral hygiene habits including a few general hygiene habits, bed time, family size, family income and dental visiting habits. The results show that 30.5% of the total sample cleaned their teeth twice or more daily and there was no significant difference between the genders for tooth cleaning frequency. Logistic regression analysis revealed that older children and those having less than two siblings were more likely to clean their teeth twice a day than the younger ones and children with more than two siblings. Furthermore, frequency of tooth cleaning was significantly lower among children of parents with low level of education and less annual income as compared with those of high education and more annual income. In addition, tooth cleaning habits were more regular in children using tooth paste and regularly visiting to the dentist. This study observed that tooth cleaning is not an isolated behaviour, but is a part of multifarious pattern of various social and behavioural factors. © 2009 The Authors. Journal compilation © 2009 Blackwell Munksgaard.

Behind the scenes of GS: keeping CERN clean

CERN Document Server

Antonella Del Rosso

2014-01-01

More than 350,000 square metres to be maintained, two different cleaning companies due to CERN’s sites being in two different countries, underground installations where cleanliness is a question of safety… the CERN team in charge of supervising cleaning services overcomes all these challenges to ensure that our workplace remains clean and pleasant every day.   Ensuring the cleanliness of sites containing a huge variety of buildings is an enormous challenge for the two experts in the GS Department in charge of cleaning services. Alain Bertrand has been at CERN for 29 years and knows all there is to know about the Organization’s buildings and what they are used for, the condition of their toilet facilities and, of course, the location of the border between France and Switzerland which, in terms of cleaning services, denotes the transition point between the two companies used. David Chameaux has been doing the same job as Alain for two years, working with him to ensu...

The Two-Word Stage: Motivated by Linguistic or Cognitive Constraints?

Science.gov (United States)

Berk, Stephanie; Lillo-Martin, Diane

2012-01-01

Child development researchers often discuss a "two-word" stage during language acquisition. However, there is still debate over whether the existence of this stage reflects primarily cognitive or linguistic constraints. Analyses of longitudinal data from two Deaf children, Mei and Cal, not exposed to an accessible first language (American Sign…

Performance and microbial community analysis of two-stage process with extreme thermophilic hydrogen and thermophilic methane production from hydrolysate in UASB reactors

DEFF Research Database (Denmark)

Kongjan, Prawit; O-Thong, Sompong; Angelidaki, Irini

2011-01-01

The two-stage process for extreme thermophilic hydrogen and thermophilic methane production from wheat straw hydrolysate was investigated in up-flow anaerobic sludge bed (UASB) reactors. Specific hydrogen and methane yields of 89ml-H2/g-VS (190ml-H2/g-sugars) and 307ml-CH4/g-VS, respectively were...... energy of 13.4kJ/g-VS. Dominant hydrogen-producing bacteria in the H2-UASB reactor were Thermoanaerobacter wiegelii, Caldanaerobacter subteraneus, and Caloramator fervidus. Meanwhile, the CH4-UASB reactor was dominated with methanogens of Methanosarcina mazei and Methanothermobacter defluvii. The results...

Chromium (Ⅵ) removal from aqueous solutions through powdered activated carbon countercurrent two-stage adsorption.

Science.gov (United States)

Wang, Wenqiang

2018-01-01

To exploit the adsorption capacity of commercial powdered activated carbon (PAC) and to improve the efficiency of Cr(VI) removal from aqueous solutions, the adsorption of Cr(VI) by commercial PAC and the countercurrent two-stage adsorption (CTA) process was investigated. Different adsorption kinetics models and isotherms were compared, and the pseudo-second-order model and the Langmuir and Freundlich models fit the experimental data well. The Cr(VI) removal efficiency was >80% and was improved by 37% through the CTA process compared with the conventional single-stage adsorption process when the initial Cr(VI) concentration was 50 mg/L with a PAC dose of 1.250 g/L and a pH of 3. A calculation method for calculating the effluent Cr(VI) concentration and the PAC dose was developed for the CTA process, and the validity of the method was confirmed by a deviation of <5%. Copyright © 2017. Published by Elsevier Ltd.

The construction of a process line for high efficiency silicon solar cells under clean-room conditions

International Nuclear Information System (INIS)

Aberle, A.; Faller, C.; Grille, T.; Glunz, S.; Kamerewerd, F.J.; Kopp, J.; Knobloch, J.; Klussmann, S.; Lauby, E.; Noel, A.; Paul, O.; Schaeffer, E.; Schubert, U.; Seitz, S.; Sterk, S.; Voss, B.; Warta, W.; Wettling, W.

1992-08-01

The aim of this research project was to plan, construct and test a clean-room technology laboratory for the manufacturing of silicon solar cells with 20% efficiency (1.5AM). In addition to the establishment of the laboratory, there existed the case of establishing the material and technological fundamentals of high-efficiency solar cells, testing and optimizing all stages of production as well as constructing test stands for accompanying characterisation work. The following final report describes the construction of the laboratory and characterisation systems, the material elements of high-efficiency solar cells as well as the most important results of solar cell production and optimisation. (orig./BWI) [de

Efficacy of single-stage and two-stage Fowler–Stephens laparoscopic orchidopexy in the treatment of intraabdominal high testis

Directory of Open Access Journals (Sweden)

Chang-Yuan Wang

2017-11-01

Conclusion: In the case of testis with good collateral circulation, single-stage F-S laparoscopic orchidopexy had the same safety and efficacy as the two-stage F-S procedure. Surgical options should be based on comprehensive consideration of intraoperative testicular location, testicular ischemia test, and collateral circumstances surrounding the testes. Under the appropriate conditions, we propose single-stage F-S laparoscopic orchidopexy be preferred. It may be appropriate to avoid unnecessary application of the two-stage procedure that has a higher cost and causes more pain for patients.

A two stage data envelopment analysis model with undesirable output

Science.gov (United States)

Shariff Adli Aminuddin, Adam; Izzati Jaini, Nur; Mat Kasim, Maznah; Nawawi, Mohd Kamal Mohd

2017-09-01

The dependent relationship among the decision making units (DMU) is usually assumed to be non-existent in the development of Data Envelopment Analysis (DEA) model. The dependency can be represented by the multi-stage DEA model, where the outputs from the precedent stage will be the inputs for the latter stage. The multi-stage DEA model evaluate both the efficiency score for each stages and the overall efficiency of the whole process. The existing multi stage DEA models do not focus on the integration with the undesirable output, in which the higher input will generate lower output unlike the normal desirable output. This research attempts to address the inclusion of such undesirable output and investigate the theoretical implication and potential application towards the development of multi-stage DEA model.

Steam Generator Chemical Cleaning Application: Korean Experience in PWR NPP

International Nuclear Information System (INIS)

Hwang, In-Ho; Varrin-Jr, Robert-D.; Little, Michael-J.; Oh, Yeon-Ok; Choo, Seong-Jib; Park, Jin-Hyeok

2012-09-01

Korea Hydro and Nuclear Power (KHNP) performed an EPRI/SGOG chemical cleaning of the secondary side of the steam generators at Ulchin Unit 3 (UCN3) in March 2011 and at Ulchin Unit 4 (UCN4) in September 2011. The steam generator chemical cleaning (SGCC) was performed with venting at the top-of-tube sheet (TTS) and at tube support plates (TSPs) 4, 5, 6, 7, 8, 9, and 10. A primary objective of this SGCC was to address outer diameter stress corrosion cracking (ODSCC), which has been observed at the TTS and TSPs in the UCN3 SGs. The EPRI/SGOG process has been shown to effectively reduce prevailing ODSCC rates at the TTS and TSPs, particularly when applied with periodic venting in this application. This was the first full-length SGCC campaign with venting performed in Korea. Ulchin Unit 3 commenced commercial operation in August 1998 and Ulchin Unit 4 commenced commercial operation in December 1999. UCN3 and UCN4 are a two-loop pressurized water reactor (PWR) of the Korea Standard Nuclear Plant (KSNP) design. The SGs contain high-temperature mill annealed (HTMA) Alloy 600 tubing and are similar in design to the Combustion Engineering CE-80. The KSNP SGs have been susceptible to outer diameter stress corrosion cracking (ODSCC), which is consistent with operating experience for other SGs containing Alloy 600HTMA tubing material. The UCN3/4 SGs have recently begun to experience ODSCC. Hankook Jungsoo Industries Co., Ltd (HaJI) was selected as the cleaning vendor by KHNP. To date, HaJI has completed five Advanced Scale Conditioning Agent (ASCA) cleaning applications and two EPRI/SGOG Steam Generator Chemical Cleaning (SGCC) campaigns for KHNP. The goal of total deposit removal of the applications were successfully achieved and the amounts are 3,579 kg at UCN3 and 3,786 kg at UCN4 which values were estimated before each cleaning by analysing ECT signal and liquid samples from the SGs. The deposits from the SGs were primarily composed of magnetite. There were no chemical

Risk in cleaning: chemical and physical exposure.

Science.gov (United States)

Wolkoff, P; Schneider, T; Kildesø, J; Degerth, R; Jaroszewski, M; Schunk, H

1998-04-23

Cleaning is a large enterprise involving a large fraction of the workforce worldwide. A broad spectrum of cleaning agents has been developed to facilitate dust and dirt removal, for disinfection and surface maintenance. The cleaning agents are used in large quantities throughout the world. Although a complex pattern of exposure to cleaning agents and resulting health problems, such as allergies and asthma, are reported among cleaners, only a few surveys of this type of product have been performed. This paper gives a broad introduction to cleaning agents and the impact of cleaning on cleaners, occupants of indoor environments, and the quality of cleaning. Cleaning agents are usually grouped into different product categories according to their technical functions and the purpose of their use (e.g. disinfectants and surface care products). The paper also indicates the adverse health and comfort effects associated with the use of these agents in connection with the cleaning process. The paper identifies disinfectants as the most hazardous group of cleaning agents. Cleaning agents contain evaporative and non-evaporative substances. The major toxicologically significant constituents of the former are volatile organic compounds (VOCs), defined as substances with boiling points in the range of 0 degree C to about 400 degrees C. Although laboratory emission testing has shown many VOCs with quite different time-concentration profiles, few field studies have been carried out measuring the exposure of cleaners. However, both field studies and emission testing indicate that the use of cleaning agents results in a temporal increase in the overall VOC level. This increase may occur during the cleaning process and thus it can enhance the probability of increased short-term exposure of the cleaners. However, the increased levels can also be present after the cleaning and result in an overall increased VOC level that can possibly affect the indoor air quality (IAQ) perceived by

Pyrolysis of Pinus pinaster in a two-stage gasifier: Influence of processing parameters and thermal cracking of tar

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