Science.gov

Sample records for acid cleaning process

  1. Novel acid-free cleaning process for mask blanks

    NASA Astrophysics Data System (ADS)

    Koster, Harald; Branz, Karsten; Dietze, Uwe; Dress, Peter; Hess, Guenter

    2005-06-01

    Knowledge of particle removal during the mask cleaning was transferred to the blank cleaning and vice versa. The experiments are focusing on a variety of blank substrates (glass substrates, chrome on glass blanks and phase shift mask blanks substrates). The principal equipment concept and the process optimization strategies for cleaning of those different kinds of blank substrates are presented. With a fixed process flow, including UV-treatment, Fulljet and MegaSonic treatment, Rinse and Dry, process parameters are varied to define the optimum process conditions. Criteria for an optimum process are particle removal efficiency in general and optical integrity for phase shift mask blanks in particular. The particle removal efficiency for all investigated blank types is within a range of 96-100%. Especially for Ta/SiO2 phase shift mask blanks we demonstrate that during the cleaning process the optical properties only change by 0.07° phase loss and 0.01% transmission loss per cleaning cycle, respectively.

  2. Isotopic compositions of s-process elements in acid-cleaned mainstream presolar silicon carbide

    NASA Astrophysics Data System (ADS)

    Liu, Nan

    Pristine meteorites contain ancient stellar relicts that survived destructions in the early solar system. Isotopic studies of these presolar grains have proven to be a unique method to understand various known and unknown nucleosynthetic processes occurred in their parent stars. Previous studies of isotopic compositions of heavy elements in mainstream SiC grains from low-mass asymptotic giant branch (AGB) stars reported contamination from solar system materials with normal isotopic compositions on grain surfaces and prevented the authors from obtaining the pure nucleosynthetic isotopic signature from stars. In addition, in these previous studies uncertainties in the major neutron source 13C within the 13C-pocket were underestimated because only the 13C mass fraction was considered as a parameter with the 13C-pocket mass and the 13C profile fixed in model calculations. The oversimplified treatment of the 13C-pocket mainly resulted from the fact that it was unclear if there exists any tracer to distinguish different effects of the 13C concentration, the 13C-pocket mass, and the 13C profile within the 13C-pocket. To address these issues, we acid-cleaned all the presolar SiC grains used in this study after their separation from the bulk Murchison meteorite. In addition, we chose to measure strontium and barium isotopic compositions in these acid-cleaned SiC grains, because both elements sit at the first and second s-process peaks along the s-process path, and are sensitive to varying parameters for the s-process in model calculations. By comparing our new acid-cleaned grain data with single grain data from previous studies for barium isotopes, we conclude that the acid-cleaning procedure is quite effective in removing surface barium contamination. For the first time, we find that model predictions for 138Ba/ 136Ba are sensitive to all three variables of the 13C-pocket adopted in AGB model calculations. In order to match the low 138Ba/ 136Ba values in a minor group of

  3. DEVELOPING AN OPTIMIZED PROCESS STRATEGY FOR ACID CLEANING OF THE SAVANNAH RIVERSITE HLW TANKS

    SciTech Connect

    Ketusky, E

    2006-12-04

    At the Savannah River Site (SRS), there remains approximately 35 million gallons of High Level Waste (HLW) that was mostly created from Purex and SRS H-Area Modified (HM) nuclear fuel cycles. The waste is contained in approximately forty-nine tanks fabricated from commercially available carbon steel. In order to minimize general corrosion, the waste is maintained as very-alkaline solution. The very-alkaline chemistry has caused hydrated metal oxides to precipitate and form a sludge heel. Over the years, the sludge waste has aged, with some forming a hardened crust. To aid in the removal of the sludge heels from select tanks for closure the use of oxalic acid to dissolve the sludge is being investigated. Developing an optimized process strategy based on laboratory analyses would be prohibitively costly. This research, therefore, demonstrates that a chemical equilibrium based software program can be used to develop an optimized process strategy for oxalic acid cleaning of the HLW tanks based on estimating resultant chemistries, minimizing resultant oxalates sent to the evaporator, and minimizing resultant solids sent to the Defense Waste Processing Facility (DWPF).

  4. Building Successful Cleaning Processes.

    ERIC Educational Resources Information Center

    Walker, John P.

    2002-01-01

    Discusses how to build a successful cleaning process in order to most effectively maintain school facilities, explaining that the cleaning processes used plays a critical role in productivity. Focuses on: developing a standardized system; making sure that employees have the right tools for the work they perform; training employees; tracking and…

  5. Cleaning Processes across NASA Centers

    NASA Technical Reports Server (NTRS)

    Hammond, John M.

    2010-01-01

    All significant surfaces of the hardware must be pre-cleaned to remove dirt, grit, scale, corrosion, grease, oil and other foreign matter prior to any final precision cleaning process. Metallic parts shall be surface treated (cleaned, passivated, pickled and/or coated) as necessary to prevent latent corrosion and contamination.

  6. Precipitation of iron, sodium, and potassium impurities from synthetic solutions modeling spent acid streams from a chemical coal cleaning process

    SciTech Connect

    Norton, G.A.; Richardson, R.G.; Markuszewski, R. ); Levine, A.D. . Dept. of Civil Engineering)

    1990-01-01

    This paper presents experiments on treating model spent acid streams from a chemical coal cleaning process by double salt precipitation which indicated that simple heating of solutions containing Fe{sub 2}(SO{sub 4}){sub 3}, Na{sub 2}SO{sub 4}, and K{sub 2}SO{sub 4} caused jarosite (KFe{sub 3}(SO{sub 4}){sub 2}(OH){sub 6}) to form preferentially to natrojarosite (NaFe{sub 3}(SO{sub 4}){sub 2}(OH){sub 6}), and precipitate yields were higher than when Na{sub 2}SO{sub 4} was the only alkali sulfate present. Virtually all of the K, about 90% of the Fe, and about 30% of the SO{sub 4}{sup 2 {minus}} could be precipitated at 95{degrees}C, while little or no Na was removed. However, simply heating Fe{sub 2}(SO{sub 4}){sub 3}/Na{sub 2}SO{sub 4} solution up to 95{degrees}C for {lt}12 hours did not produce adequate precipitate yields. When Na was the only alkali metal present, the Fe concentration in the solution had to be increased to avoid formation of undesirable iron compounds.

  7. PLUTONIUM CLEANING PROCESS

    DOEpatents

    Kolodney, M.

    1959-12-01

    A method is described for rapidly removing iron, nickel, and zinc coatings from plutonium objects while simultaneously rendering the plutonium object passive. The method consists of immersing the coated plutonium object in an aqueous acid solution containing a substantial concentration of nitrate ions, such as fuming nitric acid.

  8. Precipitation of jarosite-type double salts from spent acid solutions from a chemical coal cleaning process

    SciTech Connect

    Norton, G.

    1990-09-21

    The precipitation of jarosite compounds to remove Na, K, Fe, and SO{sub 4}{sup 2{minus}} impurities from spent acid solutions from a chemical coal cleaning process was studied. Simple heating of model solutions containing Fe{sub 2}(SO{sub 4}){sub 3}, Na{sub 2}SO{sub 4}, and K{sub 2}SO{sub 4} caused jarosite (KFe{sub 3}(SO{sub 4}){sub 2}(OH){sub 6}) to form preferentially to natrojarosite (NaFe{sub 3}(SO{sub 4}){sub 2}(OH){sub 6}). Virtually all of the K, about 90% of the Fe, and about 30% of the SO{sub 4}{sup 2{minus}} could be precipitated from those solutions at 95{degree}C, while little or no Na was removed. However, simple heating of model solutions containing only Fe{sub 2}(SO{sub 4}){sub 3} and Na{sub 2}SO{sub 4} up to 95{degree}C for {le}12 hours produced low yields of jarosite compounds, and the Fe concentration in the solution had to be increased to avoid the formation of undesirable Fe compounds. Precipitate yields could be increased dramatically in model solutions of Na{sub 2}SO{sub 4}/Fe{sub 2}(SO{sub 4}){sub 3} containing excess Fe by using either CaCO{sub 3}, Ca(OH){sub 2}, or ZnO to neutralize H{sub 2}SO{sub 4} released during hydrolysis of the Fe{sub 2}(SO{sub 4}){sub 3} and during the precipitation reactions. Results obtained from the studies with model solutions were applied to spent acids produced during laboratory countercurrent washing of coal which had been leached with a molten NaOH/KOH mixture. Results indicated that jarosite compounds can be precipitated effectively from spent acid solutions by heating for 6 hours at 80{degree}C while maintaining a pH of about 1.5 using CaCO{sub 3}.

  9. Coal cleaning process

    SciTech Connect

    Kindig, J.K.

    1994-01-11

    Fine particle coal is beneficiated in specially designed dense medium cyclones to improve particle acceleration and enhance separation efficiency. Raw coal feed is first sized to remove fine coal particles. The coarse fraction is then separated into clean coal, middlings, and refuse. Middlings are comminuted for beneficiation with the fine fraction. The fine fraction is deslimed in a countercurrent cyclone circuit and then separated as multiple fractions of different size specifications in dense medium cyclones. The dense medium contains ultra-fine magnetite particles of a narrow size distribution which aid separation and improves magnetite recovery. Magnetite is recovered from each separated fraction independently, with non-magnetic effluent water from one fraction diluting feed to a smaller-size fraction, and improving both overall coal and magnetite recovery. Magnetite recovery is in specially designed recovery units, based on particle size, with final separation in a rougher-cleaner-scavenger circuit of magnetic drum separators incorporating a high strength rare earth magnet. 12 figs.

  10. Comparison of cleaning processes with respect to cleaning efficiency

    NASA Astrophysics Data System (ADS)

    Nesladek, Pavel; Osborne, Steve; Rode, Thomas

    2011-03-01

    Photomask technology has attained feature sizes of about 50nm and below. Whereas the main feature size is still above 70-80nm at 20nm technology node recently reported e.g. by Toppan Printing Company as developed, assist features for this node are in the range of 50-60nm. One of the critical aspects of this technology development is the cleaning process. Processes are supposed to clean off contamination and particles down to a defect size of about 40nm and at the same time prevent damage to assist features in the same size range. Due to obvious trade offs between cleaning power and Feature Damage Probability (FPD), this task becomes tricky. Improvement of cleaning processes by raising the power of megasonic (MS) cleaning, or adjusting the speed and size of droplets for spray cleaning occurs at the expense of increased feature damage. Prolongation of physical cleaning steps does not necessarily leads to improvement of the cleaning as shown previously. Susceptibility to feature damage occurs predicatively according to dimension and orientation. This allows us to extrapolate a Feature Damage Limit (FDL) which approximates the smallest feature size for which a process has an acceptable probability of success. In a practical sense, the most advantageous approach seems to be to adjust the cleaning power to the maximum allowed by the FDP and then optimize to the lowest process time necessary to reach expected cleaning efficiency. Since there are several alternative physical cleaning principles, we have to pick the best one for a given application. At this point we have to raise the question of how to compare the cleaning efficiency of processes. The goal of this work is to provide a method for evaluation and comparison of cleaning efficiency between physical cleaning processes and demonstrate the method on an example. We will focus on comparing two physical cleaning processes 1MHz megasonic and binary spray process.

  11. Clean salt process final report

    SciTech Connect

    Herting, D.L.

    1996-09-30

    A process has been demonstrated in the laboratory for separating clean, virtually non-radioactive sodium nitrate from Hanford tank waste using fractional crystallization. The name of the process is the Clean Salt Process. Flowsheet modeling has shown that the process is capable of reducing the volume of vitrified low activity waste (LAW) by 80 to 90 %. Construction of the Clean Salt processing plant would cost less than $1 10 million, and would eliminate the need for building a $2.2 billion large scale vitrification plant planned for Privatization Phase 11. Disposal costs for the vitrified LAW would also be reduced by an estimated $240 million. This report provides a summary of five years of laboratory and engineering development activities, beginning in fiscal year 1992. Topics covered include laboratory testing of a variety of processing options; proof-of-principle demonstrations with actual waste samples from Hanford tanks 241-U-110 (U-110), 241-SY-101 (101-SY), and 241-AN-102 (102-AN); descriptions of the primary solubility phase diagrams that govem the process; a review of environmental regulations governing disposition of the reclaimed salt and an assessment of the potential beneficial uses of the reclaimed salt; preliminary plant design and construction cost estimates. A detailed description is given for the large scale laboratory demonstration of the process using waste from tank 241-AW-101 (101-AW), a candidate waste for 0044vitrification during Phase I Privatization.

  12. Ultrasonic cleaning of depleted uranium material as an alternative to nitric acid cleaning

    SciTech Connect

    Frye, L.E.; Senviel, C.B.

    1991-05-28

    Nitric acid is used to clean depleted uranium in the form of cast billets, and cast and wrought parts in the processing cycle and is the largest contributor of waste to the West End Treatment Facility (WETF). An estimated 27,000 gallons of liquid and 75 to 95% of all uranium received was sent to the WETF for processing from this facility in our baseline year. Because wrought parts account for the largest throughput at the nitric acid facility, an alternative cleaning method for these parts was examined first. Test results on the first part type from the wrought family showed ultrasonic cleaning to be an effective cleaning method. Since the geometry for this part presented the most difficulty in terms of ultrasonic cleaning, the entire wrought family is expected to be moved from the nitric acid facility to the ultrasonic cleaning facility. As a result, there will be an 83% reduction part throughput at the nitric acid facility which corresponds to a significant decrease in wastes sent to the WETF and a reduction in the generation and associated costs of waste overall. This change also eliminated two building moves involving two RAD areas resulting in a part movement reduction of approximately 25% which is a significant cost savings.

  13. COMPARISON OF OXALIC ACID CLEANING RESULTS AT SRS AND HANFORD AND THE IMPACT ON ENHANCED CHEMICAL CLEANING DEPLOYMENT

    SciTech Connect

    Spires, R.; Ketusky, E.

    2010-01-05

    Waste tanks must be rendered clean enough to satisfy very rigorous tank closure requirements. During bulk waste removal, most of the radioactive sludge and salt waste is removed from the waste tank. The waste residue on the tank walls and interior components and the waste heel at the bottom of the tank must be removed prior to tank closure to render the tank clean enough to meet the regulatory requirement for tank closure. Oxalic acid has been used within the DOE complex to clean residual materials from carbon steel tanks with varying degrees of success. Oxalic acid cleaning will be implemented at both the Savannah River Site and Hanford to clean tanks and serves as the core cleaning technology in the process known as Enhanced Chemical Cleaning. Enhanced Chemical Cleaning also employs a process that decomposes the spent oxalic acid solutions. The oxalic acid cleaning campaigns that have been performed at the two sites dating back to the 1980's are compared. The differences in the waste characteristics, oxalic acid concentrations, flushing, available infrastructure and execution of the campaigns are discussed along with the impact on the effectiveness of the process. The lessons learned from these campaigns that are being incorporated into the project for Enhanced Chemical Cleaning are also explored.

  14. ENHANCED CHEMICAL CLEANING: A NEW PROCESS FOR CHEMICALLY CLEANING SAVANNAH RIVER WASTE TANKS

    SciTech Connect

    Ketusky, E; Neil Davis, N; Renee Spires, R

    2008-01-17

    The Savannah River Site (SRS) has 49 high level waste (HLW) tanks that must be emptied, cleaned, and closed as required by the Federal Facilities Agreement. The current method of chemical cleaning uses several hundred thousand gallons per tank of 8 weight percent (wt%) oxalic acid to partially dissolve and suspend residual waste and corrosion products such that the waste can be pumped out of the tank. This adds a significant quantity of sodium oxalate to the tanks and, if multiple tanks are cleaned, renders the waste incompatible with the downstream processing. Tank space is also insufficient to store this stream given the large number of tanks to be cleaned. Therefore, a search for a new cleaning process was initiated utilizing the TRIZ literature search approach, and Chemical Oxidation Reduction Decontamination--Ultraviolet (CORD-UV), a mature technology currently used for decontamination and cleaning of commercial nuclear reactor primary cooling water loops, was identified. CORD-UV utilizes oxalic acid for sludge dissolution, but then decomposes the oxalic acid to carbon dioxide and water by UV treatment outside the system being treated. This allows reprecipitation and subsequent deposition of the sludge into a selected container without adding significant volume to that container, and without adding any new chemicals that would impact downstream treatment processes. Bench top and demonstration loop measurements on SRS tank sludge stimulant demonstrated the feasibility of applying CORD-UV for enhanced chemical cleaning of SRS HLW tanks.

  15. Cleaning process for contaminated superalloy powders

    NASA Technical Reports Server (NTRS)

    Anglin, A. E.

    1978-01-01

    A cleaning process for removing interstitial contaminants from superalloy powders after wet grinding is described. Typical analyses of oxygen, carbon, nitrogen, and hydrogen in ball-milled WAZ-20 superalloy samples after hydrogen plus vacuum cleaning are presented. The hydrogen cleaning step involves heating retorts containing superalloy powder twice under flowing hydrogen with a 24-hour hold at each temperature. The vacuum step involves heating cold-pressed billets two hours at an elevated temperature at a pressure of 10 microPa. It is suggested that the hydrogen plus vacuum cleaning procedure can be applied to superalloys contaminated by other substances in other industrial processes.

  16. Cleaning process for EUV optical substrates

    SciTech Connect

    Weber, F.J.; Spiller, E.A.

    1999-09-28

    A cleaning process is disclosed for surfaces with very demanding cleanliness requirements, such as extreme-ultraviolet (EUV) optical substrates. Proper cleaning of optical substrates prior to applying reflective coatings thereon is very critical in the fabrication of the reflective optics used in EUV lithographic systems, for example. The cleaning process involves ultrasonic cleaning in acetone, methanol, and a pH neutral soap, such as FL-70, followed by rinsing in de-ionized water and drying with dry filtered nitrogen in conjunction with a spin-rinse.

  17. Cleaning process for EUV optical substrates

    DOEpatents

    Weber, Frank J.; Spiller, Eberhard A.

    1999-01-01

    A cleaning process for surfaces with very demanding cleanliness requirements, such as extreme-ultraviolet (EUV) optical substrates. Proper cleaning of optical substrates prior to applying reflective coatings thereon is very critical in the fabrication of the reflective optics used in EUV lithographic systems, for example. The cleaning process involves ultrasonic cleaning in acetone, methanol, and a pH neutral soap, such as FL-70, followed by rinsing in de-ionized water and drying with dry filtered nitrogen in conjunction with a spin-rinse.

  18. ASRM process development in aqueous cleaning

    NASA Technical Reports Server (NTRS)

    Swisher, Bill

    1992-01-01

    Viewgraphs are included on process development in aqueous cleaning which is taking place at the Aerojet Advanced Solid Rocket Motor (ASRM) Division under a NASA Marshall Space and Flight Center contract for design, development, test, and evaluation of the ASRM including new production facilities. The ASRM will utilize aqueous cleaning in several manufacturing process steps to clean case segments, nozzle metal components, and igniter closures. ASRM manufacturing process development is underway, including agent selection, agent characterization, subscale process optimization, bonding verification, and scale-up validation. Process parameters are currently being tested for optimization utilizing a Taguci Matrix, including agent concentration, cleaning solution temperature, agitation and immersion time, rinse water amount and temperature, and use/non-use of drying air. Based on results of process development testing to date, several observations are offered: aqueous cleaning appears effective for steels and SermeTel-coated metals in ASRM processing; aqueous cleaning agents may stain and/or attack bare aluminum metals to various extents; aqueous cleaning appears unsuitable for thermal sprayed aluminum-coated steel; aqueous cleaning appears to adequately remove a wide range of contaminants from flat metal surfaces, but supplementary assistance may be needed to remove clumps of tenacious contaminants embedded in holes, etc.; and hot rinse water appears to be beneficial to aid in drying of bare steel and retarding oxidation rate.

  19. ASRM process development in aqueous cleaning

    NASA Astrophysics Data System (ADS)

    Swisher, Bill

    1992-12-01

    Viewgraphs are included on process development in aqueous cleaning which is taking place at the Aerojet Advanced Solid Rocket Motor (ASRM) Division under a NASA Marshall Space and Flight Center contract for design, development, test, and evaluation of the ASRM including new production facilities. The ASRM will utilize aqueous cleaning in several manufacturing process steps to clean case segments, nozzle metal components, and igniter closures. ASRM manufacturing process development is underway, including agent selection, agent characterization, subscale process optimization, bonding verification, and scale-up validation. Process parameters are currently being tested for optimization utilizing a Taguci Matrix, including agent concentration, cleaning solution temperature, agitation and immersion time, rinse water amount and temperature, and use/non-use of drying air. Based on results of process development testing to date, several observations are offered: aqueous cleaning appears effective for steels and SermeTel-coated metals in ASRM processing; aqueous cleaning agents may stain and/or attack bare aluminum metals to various extents; aqueous cleaning appears unsuitable for thermal sprayed aluminum-coated steel; aqueous cleaning appears to adequately remove a wide range of contaminants from flat metal surfaces, but supplementary assistance may be needed to remove clumps of tenacious contaminants embedded in holes, etc.; and hot rinse water appears to be beneficial to aid in drying of bare steel and retarding oxidation rate.

  20. ENVIRONMENTAL ASSESSMENT OF COAL CLEANING PROCESSES

    EPA Science Inventory

    The report summarizes a 3-year evaluation of coal cleaning processes. It discusses: physical coal cleaning (PCC) technology; the potential role of PCC in producing coals for compliance with SO2 emission regulations; pollution controls for PCC plants; assessment criteria and test ...

  1. Exhaust gas clean up process

    SciTech Connect

    Walker, R.J.

    1989-04-11

    A method of cleaning an exhaust gas containing particulates, SO/sub 2/ and NO/sub x/ includes 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/ or nitrogen-sulfonate ions and the oxides of sulfur are removed as a valuable sulfate salt.

  2. Exhaust gas clean up process

    DOEpatents

    Walker, Richard J.

    1989-01-01

    A method of cleaning an exhaust gas containing particulates, SO.sub.2 and NO.sub.x includes 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 or nitrogen-sulfonate ions and the oxides of sulfur are removed as a vaulable sulfate salt.

  3. Exhaust gas clean up process

    DOEpatents

    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.

  4. Enhanced Chemical Cleaning: A New Process for Chemically Cleaning Savannah River Waste Tanks

    SciTech Connect

    Ketusky, Edward; Spires, Renee; Davis, Neil

    2009-02-11

    At the Savannah River Site (SRS) there are 49 High Level Waste (HLW) tanks that eventually must be emptied, cleaned, and closed. The current method of chemically cleaning SRS HLW tanks, commonly referred to as Bulk Oxalic Acid Cleaning (BOAC), requires about a half million liters (130,000 gallons) of 8 weight percent (wt%) oxalic acid to clean a single tank. During the cleaning, the oxalic acid acts as the solvent to digest sludge solids and insoluble salt solids, such that they can be suspended and pumped out of the tank. Because of the volume and concentration of acid used, a significant quantity of oxalate is added to the HLW process. This added oxalate significantly impacts downstream processing. In addition to the oxalate, the volume of liquid added competes for the limited available tank space. A search, therefore, was initiated for a new cleaning process. Using TRIZ (Teoriya Resheniya Izobretatelskikh Zadatch or roughly translated as the Theory of Inventive Problem Solving), Chemical Oxidation Reduction Decontamination with Ultraviolet Light (CORD-UV{reg_sign}), a mature technology used in the commercial nuclear power industry was identified as an alternate technology. Similar to BOAC, CORD-UV{reg_sign} also uses oxalic acid as the solvent to dissolve the metal (hydr)oxide solids. CORD-UV{reg_sign} is different, however, since it uses photo-oxidation (via peroxide/UV or ozone/UV to form hydroxyl radicals) to decompose the spent oxalate into carbon dioxide and water. Since the oxalate is decomposed and off-gassed, CORD-UV{reg_sign} would not have the negative downstream oxalate process impacts of BOAC. With the oxalate destruction occurring physically outside the HLW tank, re-precipitation and transfer of the solids, as well as regeneration of the cleaning solution can be performed without adding additional solids, or a significant volume of liquid to the process. With a draft of the pre-conceptual Enhanced Chemical Cleaning (ECC) flowsheet, taking full

  5. Freezing cleans food processing wastewater

    SciTech Connect

    Not Available

    1998-01-01

    Snowfluent is a technology which atomizes wastewater effluent and sprays it into the air as ice crystals at cold temperatures. It has been found effective in treating municipal sewage and food processing wastes. This bulletin reviews pilot- and production-scale studies conducted at an Alberta malt producer to test whether the Snowfluent process has further applications for the treatment of food processing wastes. The study was designed to determine the percentage of nutrients removed by the technology, the point at which contaminants are reduced, the effect of the process on the shallow water table, and the health risk to operators involved.

  6. Freezing cleans food processing wastewater

    SciTech Connect

    1998-12-31

    Snowfluent is a technology which atomizes wastewater effluent and sprays it into the air as ice crystals at cold temperatures. It has been found effective in treating municipal sewage and food processing wastes. This bulletin reviews pilot- and production-scale studies conducted at an Alberta malt producer to test whether the Snowfluent process has further applications for the treatment of food processing wastes. The study was designed to determine the percentage of nutrients removed by the technology, the point at which contaminants are reduced, the effect of the process on the shallow water table, and the health risk to operators involved.

  7. Tank 12H Acidic Chemical Cleaning Sample Analysis And Material Balance

    SciTech Connect

    Martino, C. J.; Reboul, S. H.; Wiersma, B. J.; Coleman, C. J.

    2013-11-08

    A process of Bulk Oxalic Acid (BOA) chemical cleaning was performed for Tank 12H during June and July of 2013 to remove all or a portion of the approximately 4400 gallon sludge heel. Three strikes of oxalic acid (nominally 4 wt% or 2 wt%) were used at 55°C and tank volumes of 96- to 140-thousand gallons. This report details the sample analysis of a scrape sample taken prior to BOA cleaning and dip samples taken during BOA cleaning. It also documents a rudimentary material balance for the Tank 12H cleaning results.

  8. Influence of cleaning process on the laser-induced damage threshold of substrates

    SciTech Connect

    Shen Zhengxiang; Ding Tao; Ye Xiaowen; Wang Xiaodong; Ma Bin; Cheng Xinbin; Liu Huasong; Ji Yiqin; Wang Zhanshan

    2011-03-20

    The cleaning process of optical substrates plays an important role during the manufacture of high-power laser coatings. Two kinds of substrates, fused silica and BK7 glass, and two cleaning processes, called process 1 and process 2 having different surfactant solutions and different ultrasonic cleaning parameters, are adopted to compare the influence of the ultrasonic cleaning technique on the substrates. The evaluation standards of the cleaning results include contaminant-removal efficiency, weak absorption, and laser-induced damage threshold of the substrates. For both fused silica and BK7, process 2 is more efficient than process 1. Because acid and alkaline solutions can increase the roughness of BK7, process 2 is unsuitable for BK7 glass cleaning. The parameters of the cleaning protocol should be changed depending on the material of the optical components and the type of contamination.

  9. Integrated coal cleaning, liquefaction, and gasification process

    DOEpatents

    Chervenak, Michael C.

    1980-01-01

    Coal is finely ground and cleaned so as to preferentially remove denser ash-containing particles along with some coal. The resulting cleaned coal portion having reduced ash content is then fed to a coal hydrogenation system for the production of desirable hydrocarbon gases and liquid products. The remaining ash-enriched coal portion is gasified to produce a synthesis gas, the ash is removed from the gasifier usually as slag, and the synthesis gas is shift converted with steam and purified to produce the high purity hydrogen needed in the coal hydrogenation system. This overall process increases the utilization of as-mined coal, reduces the problems associated with ash in the liquefaction-hydrogenation system, and permits a desirable simplification of a liquids-solids separation step otherwise required in the coal hydrogenation system.

  10. Evaluation Of Sludge Heel Dissolution Efficiency With Oxalic Acid Cleaning At Savannah River Site

    SciTech Connect

    Sudduth, Christie; Vitali, Jason; Keefer, Mark

    2014-01-08

    The chemical cleaning process baseline strategy at the Savannah River Site was revised to improve efficiency during future execution of the process based on lessons learned during previous bulk oxalic acid cleaning activities and to account for operational constraints imposed by safety basis requirements. These improvements were also intended to transcend the difficulties that arise from waste removal in higher rheological yield stress sludge tanks. Tank 12 implemented this improved strategy and the bulk oxalic acid cleaning efforts concluded in July 2013. The Tank 12 radiological removal results were similar to previous bulk oxalic acid cleaning campaigns despite the fact that Tank 12 contained higher rheological yield stress sludge that would make removal more difficult than the sludge treated in previous cleaning campaigns. No appreciable oxalate precipitation occurred during the cleaning process in Tank 12 compared to previous campaigns, which aided in the net volume reduction of 75-80%. Overall, the controls established for Tank 12 provide a template for an improved cleaning process.

  11. Is peracetic acid suitable for the cleaning step of reprocessing flexible endoscopes?

    PubMed Central

    Kampf, Günter; Fliss, Patricia M; Martiny, Heike

    2014-01-01

    The bioburden (blood, protein, pathogens and biofilm) on flexible endoscopes after use is often high and its removal is essential to allow effective disinfection, especially in the case of peracetic acid-based disinfectants, which are easily inactivated by organic material. Cleaning processes using conventional cleaners remove a variable but often sufficient amount of the bioburden. Some formulations based on peracetic acid are recommended by manufacturers for the cleaning step. We performed a systematic literature search and reviewed the available evidence to clarify the suitability of peracetic acid-based formulations for cleaning flexible endoscopes. A total of 243 studies were evaluated. No studies have yet demonstrated that peracetic acid-based cleaners are as effective as conventional cleaners. Some peracetic acid-based formulations have demonstrated some biofilm-cleaning effects and no biofilm-fixation potential, while others have a limited cleaning effect and a clear biofilm-fixation potential. All published data demonstrated a limited blood cleaning effect and a substantial blood and nerve tissue fixation potential of peracetic acid. No evidence-based guidelines on reprocessing flexible endoscopes currently recommend using cleaners containing peracetic acid, but some guidelines clearly recommend not using them because of their fixation potential. Evidence from some outbreaks, especially those involving highly multidrug-resistant gram-negative pathogens, indicated that disinfection using peracetic acid may be insufficient if the preceding cleaning step is not performed adequately. Based on this review we conclude that peracetic acid-based formulations should not be used for cleaning flexible endoscopes. PMID:25228941

  12. Is peracetic acid suitable for the cleaning step of reprocessing flexible endoscopes?

    PubMed

    Kampf, Günter; Fliss, Patricia M; Martiny, Heike

    2014-09-16

    The bioburden (blood, protein, pathogens and biofilm) on flexible endoscopes after use is often high and its removal is essential to allow effective disinfection, especially in the case of peracetic acid-based disinfectants, which are easily inactivated by organic material. Cleaning processes using conventional cleaners remove a variable but often sufficient amount of the bioburden. Some formulations based on peracetic acid are recommended by manufacturers for the cleaning step. We performed a systematic literature search and reviewed the available evidence to clarify the suitability of peracetic acid-based formulations for cleaning flexible endoscopes. A total of 243 studies were evaluated. No studies have yet demonstrated that peracetic acid-based cleaners are as effective as conventional cleaners. Some peracetic acid-based formulations have demonstrated some biofilm-cleaning effects and no biofilm-fixation potential, while others have a limited cleaning effect and a clear biofilm-fixation potential. All published data demonstrated a limited blood cleaning effect and a substantial blood and nerve tissue fixation potential of peracetic acid. No evidence-based guidelines on reprocessing flexible endoscopes currently recommend using cleaners containing peracetic acid, but some guidelines clearly recommend not using them because of their fixation potential. Evidence from some outbreaks, especially those involving highly multidrug-resistant gram-negative pathogens, indicated that disinfection using peracetic acid may be insufficient if the preceding cleaning step is not performed adequately. Based on this review we conclude that peracetic acid-based formulations should not be used for cleaning flexible endoscopes. PMID:25228941

  13. Aqueous cleaning and verification processes for precision cleaning of small parts

    NASA Technical Reports Server (NTRS)

    Allen, Gale J.; Fishell, Kenneth A.

    1995-01-01

    The NASA Kennedy Space Center (KSC) Materials Science Laboratory (MSL) has developed a totally aqueous process for precision cleaning and verification of small components. In 1990 the Precision Cleaning Facility at KSC used approximately 228,000 kg (500,000 lbs) of chlorofluorocarbon (CFC) 113 in the cleaning operations. It is estimated that current CFC 113 usage has been reduced by 75 percent and it is projected that a 90 percent reduction will be achieved by the end of calendar year 1994. The cleaning process developed utilizes aqueous degreasers, aqueous surfactants, and ultrasonics in the cleaning operation and an aqueous surfactant, ultrasonics, and Total Organic Carbon Analyzer (TOCA) in the nonvolatile residue (NVR) and particulate analysis for verification of cleanliness. The cleaning and verification process is presented in its entirety, with comparison to the CFC 113 cleaning and verification process, including economic and labor costs/savings.

  14. Post cleaning of chemical mechanical polishing process

    NASA Astrophysics Data System (ADS)

    Liu, Chi-Wen; Dai, Bau-Tong; Yeh, Ching-Fa

    1996-02-01

    We describe a study on the effect of the electrostatic nature in silica particles on the post CMP cleaning behavior. A fall-off for the zeta potential of silica particles is observed as the pH of dip solutions is increased. In this study, we also observed that particle counts on the SiO 2 and the Si 3N 4 dielectric films had a similar dependence on the pH. Furthermore, we confirmed that surface hardness of the wafer is an important factor for particles physically embedded in different dielectric materials during and after the CMP process. The nanoscale surface hardness of dielectric films was measured by the nanoindentation technique. Experimental results showed that particles had difficulty attaching to a harder surface of the dielectric film.

  15. Effect of two cleaning processes for bone allografts on gentamicin impregnation and in vitro antibiotic release.

    PubMed

    Coraça-Huber, D C; Hausdorfer, J; Fille, M; Steidl, M; Nogler, M

    2013-06-01

    Bone allografts are a useful and sometimes indispensable tool for the surgeon to repair bone defects. Microbial contamination is a major reason for discarding allografts from bone banks. To improve the number of safe allografts, we suggest chemical cleaning of the grafts followed by antibiotic impregnation. Comparison of two chemical cleaning processes for bone allografts aiming for antibiotic impregnation and consequently delivery rates in vitro. Bone chips of 5-10 mm were prepared from human femoral heads. Two cleaning methods (cleaning A and cleaning B) based on solutions containing hydrogen peroxide, paracetic acid, ethanol and biological detergent were carried out and compared. After the cleaning processes, the bone chips were impregnated with gentamicin. Bacillus subtilis bioassay was used to determine the gentamicin release after intervals of 1-7 days. Differences were compared with non-parametric Mann-Whitney U tests. The zones of inhibition obtained from the bone grafts cleaned with both cleaning processes were similar between the groups. The concentration of the released antibiotic was decreasing gradually over time, following a similar pattern for both groups. The cleaning procedure A as well as the cleaning procedure B for bone allografts allowed the impregnation with gentamicin powder in the same concentrations in both groups. The delivery of gentamicin was similar for both groups. Both cleaning procedures were easy to be carried out, making them suitable for routine use at the bone banks. PMID:22581168

  16. Development of the LICADO coal cleaning process

    SciTech Connect

    Not Available

    1990-07-31

    Development of the liquid carbon dioxide process for the cleaning of coal was performed in batch, variable volume (semi-continuous), and continuous tests. Continuous operation at feed rates up to 4.5 kg/hr (10-lb/hr) was achieved with the Continuous System. Coals tested included Upper Freeport, Pittsburgh, Illinois No. 6, and Middle Kittanning seams. Results showed that the ash and pyrite rejections agreed closely with washability data for each coal at the particle size tested (-200 mesh). A 0.91 metric ton (1-ton) per hour Proof-of-Concept Plant was conceptually designed. A 181 metric ton (200 ton) per hour and a 45 metric ton (50 ton) per hour plant were sized sufficiently to estimate costs for economic analyses. The processing costs for the 181 metric ton (200 ton) per hour and 45 metric ton (50 ton) per hour were estimated to be $18.96 per metric ton ($17.20 per ton) and $11.47 per metric ton ($10.40 per ton), respectively for these size plants. The costs for the 45 metric ton per hour plant are lower because it is assumed to be a fines recovery plant which does not require a grinding circuit of complex waste handling system.

  17. Cleaning Process Development for Metallic Additively Manufactured Parts

    NASA Technical Reports Server (NTRS)

    Tramel, Terri L.; Welker, Roger; Lowery, Niki; Mitchell, Mark

    2014-01-01

    Additive Manufacturing of metallic components for aerospace applications offers many advantages over traditional manufacturing techniques. As a new technology, many aspects of its widespread utilization remain open to investigation. Among these are the cleaning processes that can be used for post finishing of parts and measurements to verify effectiveness of the cleaning processes. Many cleaning and drying processes and measurement methods that have been used for parts manufactured using conventional techniques are candidates that may be considered for cleaning and verification of additively manufactured parts. Among these are vapor degreasing, ultrasonic immersion and spray cleaning, followed by hot air drying, vacuum baking and solvent displacement drying. Differences in porosity, density, and surface finish of additively manufactured versus conventionally manufactured parts may introduce new considerations in the selection of cleaning and drying processes or the method used to verify their effectiveness. This presentation will review the relative strengths and weaknesses of different candidate cleaning and drying processes as they may apply to additively manufactured metal parts for aerospace applications. An ultrasonic cleaning technique for exploring the cleanability of parts will be presented along with an example using additively manufactured Inconel 718 test specimens to illustrate its use. The data analysis shows that this ultrasonic cleaning approach results in a well-behaved ultrasonic cleaning/extraction behavior. That is, it does not show signs of accelerated cavitation erosion of the base material, which was later confirmed by neutron imaging. In addition, the analysis indicated that complete cleaning would be achieved by ultrasonic immersion cleaning at approximately 5 minutes, which was verified by subsequent cleaning of additional parts.

  18. Development of the chemical and electrochemical coal cleaning (CECC) process

    SciTech Connect

    Yoon, Roe-Hoan; Basilio, C.I.

    1992-05-01

    The Chemical and Electrochemical Coal Cleaning (CECC) process developed at Virginia Polytechnic Institute and State University was studied further in this project. This process offers a new method of physically cleaning both low- and high-rank coals without requiring fine grinding. The CECC process is based on liberating mineral matter from coal by osmotic pressure. The majority of the work was conducted on Middle Wyodak, Pittsburgh No. 8 and Elkhorn No. 3 coals. The coal samples were characterized for a variety of physical and chemical properties. Parametric studies were then conducted to identify the important operating parameters and to establish the optimum conditions. In addition, fundamental mechanisms of the process were studied, including mineral matter liberation, kinetics of mineral matter and pyrite dissolution, ferric ion regeneration schemes and alternative methods of separating the cleaned coal from the liberated mineral matter. The information gathered from the parametric and fundamental studies was used in the design, construction and testing of a bench-scale continuous CECC unit. Using this unit, the ash content of a Middle Wyodak coal was reduced from 6.96 to 1.61% at a 2 lbs/hr throughput. With an Elkhorn No. 3 sample, the ash content was reduced from 9.43 to 1.8%, while the sulfur content was reduced from 1.57 to 0.9%. The mass balance and liberation studies showed that liberation played a more dominant role than the chemical dissolution in removing mineral matter and inorganic sulfur from the different bituminous coals tested. However, the opposite was found to be the case for the Wyodak coal since this coal contained a significant amount of acid-soluble minerals.

  19. Mechanisms of actions of sodium hypochlorite in cleaning and disinfection processes.

    PubMed

    Fukuzaki, Satoshi

    2006-12-01

    Sodium hypochlorite (NaOCl) is the most widely used disinfectant in the food industry despite the increasing availability of other disinfectants. Sodium hypochlorite fulfills many requirements as the ideal disinfectant and furthermore it has an excellent cleaning action. The effectiveness of sodium hypochlorite in the cleaning and disinfection processes depends on the concentration of available chlorine and the pH of the solution. Hypochlorous acid (HOCl) is a weak acid and dissociates to the hypochlorite ion (-OCl) and proton (H+) depending on the solution pH. It is generally believed that HOCl is the active species in the germicidal action, whereas the concentration of -OCl is a key factor determining the cleaning efficiency. This implies that the optimal pH region of the germicidal activity of sodium hypochlorite differs from that of its cleaning activity. This paper describes the theory and practice of the cleaning and disinfecting operations based on the use of sodium hypochlorite solution. PMID:17190269

  20. EUV mask surface cleaning effects on lithography process performance

    SciTech Connect

    George, Simi; Baclea-an, Lorie Mae; Naulleau, Patrick; Chen, Robert J.; Liang, Ted

    2010-06-18

    The reflective, multilayer based, mask architectures for extreme ultraviolet (EUV) lithography are highly susceptible to surface oxidation and contamination. As a result, EUV masks are expected to undergo cleaning processes in order to maintain the lifetimes necessary for high volume manufacturing. For this study, the impact of repetitive cleaning of EUV masks on imaging performance was evaluated. Two, high quality industry standard, EUV masks are used for this study with one of the masks undergoing repeated cleaning and the other one kept as a reference. Lithographic performance, in terms of process window analysis and line edge roughness, was monitored after every two cleans and compared to the reference mask performance. After 8x clean, minimal degradation is observed. The cleaning cycles will be continued until significant loss imaging fidelity is found.

  1. Preliminary Results of Cleaning Process for Lubricant Contamination

    NASA Astrophysics Data System (ADS)

    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.

  2. RESULTS OF THE 2H EVAPORATOR ACID CLEANING AND IN-POT NEUTRALIZATION

    SciTech Connect

    Wilmarth, B; Phillip Norris, P; Terry Allen, T

    2007-05-29

    The estimated 200 gallons of sodium aluminosilicate scale (NAS) present in the 242-16H Evaporator pot prior to chemical cleaning was subjected to four batches of 1.5 M (9 wt%) nitric acid. Each batch was neutralized with 19 M (50 wt %) sodium hydroxide (caustic) before transfer to Tank 38. The chemical cleaning process began on November 20, 2006, and was terminated on December 10, 2006. An inspection of the pot's interior was performed and based on data gathered during that inspection; the current volume of scale in the pot is conservatively estimated to be 36.3 gallons, which is well below the 200 gallon limit specified in the Technical Safety Requirements. In addition, the performance during all aspects of cleaning agreed well with the flowsheet developed at the bench and pilot scale. There were some lessons learned during the cleaning outage and are detailed in appendices of this report.

  3. Development of cleaning process for immersion lithography

    NASA Astrophysics Data System (ADS)

    Chang, Ching Yu; Yu, D. C.; Lin, John C.; Lin, Burn J.

    2006-03-01

    In immersion lithography, DI water fills the space between the resist surface and the last lens element. However water is also a good solvent for most of the leaching compounds from resists. The leaching materials from the resist and the original impurities in the water from pipelines pose a significant risk on bottom lens deterioration, wafer surface particles, and facility contamination. If the bottom lens surface deteriorates, it can cause flare and reduce transparency. Particles on the wafer surface can degrade image formation. In addition to contaminating the facility, the impurity inside the water can cause stains or defects after the water is evaporated from the wafer surface. In order to reduce the impact of such contamination, we have evaluated many chemicals for removing organic contamination as well as particles. We have collected and characterized immersion-induced particles from cleaning studies on bare silicon wafers. We have also used oxide wafers to simulate the lens damage caused by the cleaning chemicals. In case, a mega sonic power is not suitable for scanners last lens element in production FABs, the emulsion concept has also been adopted to remove the lens organic contaminants. We have studied many chemical and mechanical methods for tool cleaning, and identified those that possess good organic solubility and particle removal efficiency. These cleaning methods will be used in periodic maintenance procedures to ensure freedom from defects in immersion lithography.

  4. ENVIRONMENTAL ASSESSMENT OF COAL CLEANING PROCESSES: TECHNOLOGY OVERVIEW

    EPA Science Inventory

    The report gives a background against which requirements for further developments of coal cleaning technology and control techniques for the associated pollutants can be established, as part of a review of U.S. coal cleaning process technologies and related technologies for envir...

  5. ENVIRONMENTAL ASSESSMENT OF COAL CLEANING PROCESSES; MASTER TEST PLAN

    EPA Science Inventory

    The report gives a master test plan, presenting the objectives and general structure of a field testing program designed for an environmental source assessment of coal cleaning processes. The report, to be used to prepare test plans for individual coal cleaning sites, reflects th...

  6. ENVIRONMENTAL ASSESSMENT OF COAL CLEANING PROCESSES. SECOND ANNUAL REPORT

    EPA Science Inventory

    The report describes the second year's work for EPA by Battelle's Columbus Laboratories on an environmental assessment of coal cleaning processes. Program activities included systems studies, data acquisition, and general program support. (1) Systems studies have been directed at...

  7. PROJECT LISTING - CLEAN PROCESSES BRANCH (SUSTAINABLE TECHNOLOGY DIVISION, NRMRL)

    EPA Science Inventory

    This list of projects for the Clean Processes Branch (CPB)of NRMRL's Sustainable Technology Division covers CPB projects in the areas of metal finishing and electronics pollution prevention; green engineering for chemical synthesis; solvent and coatings alternatives; separations ...

  8. A Hybrid Gas Cleaning Process for Production of Ultraclean Syngas

    SciTech Connect

    Merkel, T.C.; Turk, B.S.; Gupta, R.P.; Cicero, D.C.; Jain, S.C.

    2002-09-20

    The overall objective of this project is to develop technologies for cleaning/conditioning IGCC generated syngas to meet contaminant tolerance limits for fuel cell and chemical production applications. The specific goals are to develop processes for (1) removal of reduced sulfur species to sub-ppm levels using a hybrid process consisting of a polymer membrane and a regenerable ZnO-coated monolith or a mixed metal oxide sorbent; (2) removal of hydrogen chloride vapors to sub-ppm levels using an inexpensive, high-surface-area material; and (3) removal of NH3 with acidic adsorbents followed by conversion of this NH3 into nitrogen and water. Existing gasification technologies can effectively and efficiently convert a wide variety of carbonaceous feedstocks (coal, petcoke, resids, biomass, etc.) into syngas, which predominantly contains carbon monoxide and hydrogen. Unfortunately, the impurities present in these carbonaceous feedstocks are converted to gaseous contaminants such as H2S, COS, HCl, NH3, alkali macromolecules and heavy metal compounds (such as Hg) during the gasification process. Removal of these contaminants using conventional processes is thermally inefficient and capital intensive. This research and development effort is focused on investigation of modular processes for removal of sulfur, chlorine, nitrogen and mercury compounds from syngas at elevated temperature and pressures at significantly lower costs than conventional technologies.

  9. NITRIC ACID PICKLING PROCESS

    DOEpatents

    Boller, E.R.; Eubank, L.D.

    1958-08-19

    An improved process is described for the treatment of metallic uranium surfaces preparatory to being given hot dip coatings. The process consists in first pickling the uraniunn surInce with aqueous 50% to 70% nitric acid, at 60 to 70 deg C, for about 5 minutes, rinsing the acid solution from the uranium article, promptly drying and then passing it through a molten alkali-metal halide flux consisting of 42% LiCl, 53% KCla and 5% NaCl into a molten metal bath consisting of 85 parts by weight of zinc and 15 parts by weight of aluminum

  10. Analysis of chemical coal cleaning processes. Final report

    SciTech Connect

    Not Available

    1980-06-01

    Six chemical coal cleaning processes were examined. Conceptual designs and costs were prepared for these processes and coal preparation facilities, including physical cleaning and size reduction. Transportation of fine coal in agglomerated and unagglomerated forms was also discussed. Chemical cleaning processes were: Pittsburgh Energy Technology Center, Ledgemont, Ames Laboratory, Jet Propulsion Laboratory (two versions), and Guth Process (KVB). Three of the chemical cleaning processes are similar in concept: PETC, Ledgemont, and Ames. Each of these is based on the reaction of sulfur with pressurized oxygen, with the controlling factor being the partial pressure of oxygen in the reactor. All of the processes appear technically feasible. Economic feasibility is less certain. The recovery of process chemicals is vital to the JPL and Guth processes. All of the processes consume significant amounts of energy in the form of electric power and coal. Energy recovery and increased efficiency are potential areas for study in future more detailed designs. The Guth process (formally designed KVB) appears to be the simplest of the systems evaluated. All of the processes require future engineering to better determine methods for scaling laboratory designs/results to commercial-scale operations. A major area for future engineering is to resolve problems related to handling, feeding, and flow control of the fine and often hot coal.

  11. Biosilica structures obtained from Nitzschia, Ditylum, Skeletonema, and Coscinodiscus diatom by a filtration-aided acid cleaning method.

    PubMed

    Wang, Yu; Zhang, Deyuan; Cai, Jun; Pan, Junfeng; Chen, Mingli; Li, Aobo; Jiang, Yonggang

    2012-09-01

    A filtration-aided acid cleaning method was used to collect biosilica structures from a diatom culture medium, natural seawater, or water bloom. Cell extraction, acid cleaning, and acid removal were all performed on a polytetrafluoroethylene (PTFE) filter cloth, significantly improving the treatment capacity and efficiency of the traditional acid wash method. Five typical diatoms were cultivated in the laboratory for acid cleaning. Different growth speeds were introduced, and different process parameters for acid cleaning were utilized. After the acid cleaning, biosilica structures were collected from the frustules of diatoms using different methods. Girdle bands and valves of Coscinodiscus sp. were separated by floating of the valves. Central spines of Ditylum brightwellii and valves of Skeletonema costatum were separately collected by settling or filtration. Rod-like frustules, such as those of Bacillaris paradoxa, are not suitable for large quantities of acid wash. The silica structures were observed and tested using an AFM-calibrated glass needle to determine their elasticity. Elasticity tests showed that ringent girdle bands are more flexible than complete ones (Coscinodiscus sp.) and that both long-chain clusters of Nitzschia palea and central spines of D. brightwellii have certain elasticities. The required pressure for deforming or breaking the biosilica structures of diatoms was also determined. PMID:22552901

  12. Update-processing steam generator cleaning solvent at Palo Verde

    SciTech Connect

    Peters, G.

    1996-10-01

    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 moss{close_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.

  13. Effect of processing rate on seed cotton cleaning equipment performance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The processing rate per unit width of seed cotton cleaning equipment– cylinder cleaners and stick machines– recommended by manufacturers is 4.8-8.2 bales hr-1 m-1 (1.5-2.5 bales hr-1 ft-1). Survey data has indicated that many gins exceed this processing rate. Previous research with picker-harvested ...

  14. Alternative, Green Processes for the Precision Cleaning of Aerospace Hardware

    NASA Technical Reports Server (NTRS)

    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

  15. TREATMENT TANK CORROSION STUDIES FOR THE ENHANCED CHEMICAL CLEANING PROCESS

    SciTech Connect

    Wiersma, B.

    2011-08-24

    Radioactive waste is stored in high level waste tanks on the Savannah River Site (SRS). Savannah River Remediation (SRR) is aggressively seeking to close the non-compliant Type I and II waste tanks. The removal of sludge (i.e., metal oxide) heels from the tank is the final stage in the waste removal process. The Enhanced Chemical Cleaning (ECC) process is being developed and investigated by SRR to aid in Savannah River Site (SRS) High-Level Waste (HLW) as an option for sludge heel removal. Corrosion rate data for carbon steel exposed to the ECC treatment tank environment was obtained to evaluate the degree of corrosion that occurs. These tests were also designed to determine the effect of various environmental variables such as temperature, agitation and sludge slurry type on the corrosion behavior of carbon steel. Coupon tests were performed to estimate the corrosion rate during the ECC process, as well as determine any susceptibility to localized corrosion. Electrochemical studies were performed to develop a better understanding of the corrosion mechanism. The tests were performed in 1 wt.% and 2.5 wt.% oxalic acid with HM and PUREX sludge simulants. The following results and conclusions were made based on this testing: (1) In 1 wt.% oxalic acid with a sludge simulant, carbon steel corroded at a rate of less than 25 mpy within the temperature and agitation levels of the test. No susceptibility to localized corrosion was observed. (2) In 2.5 wt.% oxalic acid with a sludge simulant, the carbon steel corrosion rates ranged between 15 and 88 mpy. The most severe corrosion was observed at 75 C in the HM/2.5 wt.% oxalic acid simulant. Pitting and general corrosion increased with the agitation level at this condition. No pitting and lower general corrosion rates were observed with the PUREX/2.5 wt.% oxalic acid simulant. The electrochemical and coupon tests both indicated that carbon steel is more susceptible to localized corrosion in the HM/oxalic acid environment than

  16. Contamination detection NDE for cleaning process inspection

    NASA Technical Reports Server (NTRS)

    Marinelli, W. J.; Dicristina, V.; Sonnenfroh, D.; Blair, D.

    1995-01-01

    In the joining of multilayer materials, and in welding, the cleanliness of the joining surface may play a large role in the quality of the resulting bond. No non-intrusive techniques are currently available for the rapid measurement of contamination on large or irregularly shaped structures prior to the joining process. An innovative technique for the measurement of contaminant levels in these structures using laser based imaging is presented. The approach uses an ultraviolet excimer laser to illuminate large and/or irregular surface areas. The UV light induces fluorescence and is scattered from the contaminants. The illuminated area is viewed by an image-intensified CCD (charge coupled device) camera interfaced to a PC-based computer. The camera measures the fluorescence and/or scattering from the contaminants for comparison with established standards. Single shot measurements of contamination levels are possible. Hence, the technique may be used for on-line NDE testing during manufacturing processes.

  17. Photomask cleaning process improvement to minimize ArF haze

    NASA Astrophysics Data System (ADS)

    Graham, Michael; McDonald, Andrew

    2008-04-01

    Growth of "haze" defects on photomasks exposed in ArF lithography is recognized as a serious problem. Haze defects that have grown to detectable sizes can be analysed in situ by techniques such as EDX or Raman, but to analyze at the photomask manufacturing stage requires extraction of residues by solution in DI water. The effect of extraction conditions, including surface area and material, water volume, time, and temperature, has been studied. A standard method to compare residual ion levels is proposed. Various methods for reducing residual ion levels from the photomask cleaning process have been published. These include SPM reduction, oxygen plasma, SC1 dilution, Megasonic agitation, hot rinse, UV exposure, thermal bake, ozone water, ozone gas, and hydrogenated water. Critical parameters for the cleaning process, besides residual ion levels and contamination removal efficiency, include CD shift, AR/chrome damage, scatter bar damage, and on phase shift masks, the change in phase and transmission. An optimized process combining conventional and novel techniques is described. Data is presented to show the importance of controlling all resist strip and clean processes, not just the final clean. It has achieved sulphate levels of 0.2ng/cm2 (well below the critical level for haze growth), as well as improved results for the other critical parameters. This process has been demonstrated to allow ArF exposure of large numbers of wafers without the appearance of haze defects.

  18. Reducing the emission of ozone depleting chemicals through use of a self-cleaning soldering process

    SciTech Connect

    Lichtenberg, L.; Martin, G.; Van Buren, P.; Iman, R.; Paffett, M.T.

    1991-12-31

    Motorola has jointed with Sandia and Los Alamos National Laboratories to perform work under a Cooperative Research and Development Agreement (CRADA) to reduce the use of CFC`s and other ozone depleting printing wiring board (PWB) cleaning solvents. This study evaluated the use of a new soldering process that uses dilute adipic acid in lieu of rosin flux. The process consumes the adipic acid in lieu of rosin flux. The process consumes the adipic acid during the soldering process and precludes the need for subsequent cleaning with ozone depleting solvents. This paper presents results from a series of designed experiments that evaluated PWB cleanliness as a function of various levels of machine control parameters. The study included a comprehensive hardware reliability evaluation, which included environmental conditioning, cleanliness testing, surface chemical analysis, surface insulation resistance testing, along with electrical, mechanical and long term storage testing. The results of this study that the new process produces quality, reliable hardware over a wide range of processing parameters. Adoption of this process, which eliminates the need for supplemental cleaning, will have a positive impact on many environmental problems, including depletion of the ozone layer.

  19. Reducing the emission of ozone depleting chemicals through use of a self-cleaning soldering process

    SciTech Connect

    Lichtenberg, L.; Martin, G.; Van Buren, P. . Government Electronics Group); Iman, R. ); Paffett, M.T. )

    1991-01-01

    Motorola has jointed with Sandia and Los Alamos National Laboratories to perform work under a Cooperative Research and Development Agreement (CRADA) to reduce the use of CFC's and other ozone depleting printing wiring board (PWB) cleaning solvents. This study evaluated the use of a new soldering process that uses dilute adipic acid in lieu of rosin flux. The process consumes the adipic acid in lieu of rosin flux. The process consumes the adipic acid during the soldering process and precludes the need for subsequent cleaning with ozone depleting solvents. This paper presents results from a series of designed experiments that evaluated PWB cleanliness as a function of various levels of machine control parameters. The study included a comprehensive hardware reliability evaluation, which included environmental conditioning, cleanliness testing, surface chemical analysis, surface insulation resistance testing, along with electrical, mechanical and long term storage testing. The results of this study that the new process produces quality, reliable hardware over a wide range of processing parameters. Adoption of this process, which eliminates the need for supplemental cleaning, will have a positive impact on many environmental problems, including depletion of the ozone layer.

  20. NICE3 SO3 Cleaning Process in Semiconductor Manufacturing

    SciTech Connect

    Blazek, S.

    1999-01-29

    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.

  1. NATO/CCMS PILOT STUDY - CLEAN PRODUCTS AND PROCESSES

    EPA Science Inventory

    The proposed objective of the NATO/CCMS Pilot on clean products and processes is to facilitate further gains in pollution prevention, waste minimization, and design for the environment. It is anticipated that the free exchange of knowledge, experience, data, and models will fost...

  2. NATO/CCMS PILOT STUDY ON CLEAN PRODUCTS & PROCESSES

    EPA Science Inventory

    Led by the United States, represented by the U.S. Environmental Protection Agency's (EPA's) National Risk Management Research Laboratory, the Pilot Study on Clean Products and Processes was instituted to create an international forum where current trends, developments, and expert...

  3. Characterization of the cleaning process on a transferred graphene

    SciTech Connect

    Huang, Li-Wei; Chang, Cheng-Kai; Chien, Fan-Ching; Chen, Kuei-Hsien; Chen, Peilin; Chen, Fu-Rong; Chang, Chia-Seng

    2014-09-01

    Intrinsic graphene possesses many outstanding physical and chemical properties, but their full explorations are often hindered by the effects of substrate and/or contamination. The authors employ the ultrahigh vacuum transmission electron microscopy equipped with a residual gas analyzer to in-situ characterize an effective decontamination process on a suspended graphene. Raman spectroscopic spectra further verify the cleanness of the resultant graphene membrane. The authors also present two contrasting growth morphologies of copper nanoparticles obtained on both clean and unclean graphene surfaces and show that the intrinsic growth dynamics can only manifest on the surface without contaminations.

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

    SciTech Connect

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

    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)

  5. Northwestern University Facility for Clean Catalytic Process Research

    SciTech Connect

    Marks, Tobin Jay

    2013-05-08

    Northwestern University with DOE support created a Facility for Clean Catalytic Process Research. This facility is designed to further strengthen our already strong catalysis research capabilities and thus to address these National challenges. Thus, state-of-the art instrumentation and experimentation facility was commissioned to add far greater breadth, depth, and throughput to our ability to invent, test, and understand catalysts and catalytic processes, hence to improve them via knowledge-based design and evaluation approaches.

  6. The politics of markets: The acid rain control policy in the 1990 Clean Air Act amendments

    SciTech Connect

    Kete, N.

    1993-01-01

    This thesis is a review and critique of the development of the acid rain control policy codified as Title IV of the Clean Air Act. The amendments include provisions to address acid rain-air pollution that has been transformed and transported over long distances. Title IV also embodies the first large scale adoption of market principles and economic incentives in the cause of environmental protection. The acid rain control amendments are being hailed as a break with past environmental protection practice and are being offered as a model for further regulatory reform. The thesis looks at the roots of the acid rain policy and considers the set of legal, social, and economic relations embedded in the policy which define the nature of its legal controls over pollution and its inverse, environmental quality. It explores whether the creation of the emissions allowance trading system changes the social relationships that prevailed under the pre-amended Clean Air Act. It responds to and rebuts the concerns of some critics that the policy represents an alienation of the public's right to clean air. A review of the acid rain policymaking process provides a recent and concrete example of the two central concerns inherent in public policy: the making of decisions that establish institutional arrangements, or structures, that both constrain and liberate individual action at the operational level; and the search for the boundary between autonomous behavior and collective decision making. The policy responds to regulatory reform recommendations concerned with improving the effectiveness, accountability, and cost-effectiveness of environmental protection. As a model for future policymaking, the policy goes beyond and encompasses more than the welfare economics ideal of static economic efficiency and the [open quotes]free market environmentalism[close quotes] emphasis on private property and common law.

  7. Enhancing the performance of multilayer-dielectric diffraction gratings through cleaning process modifications and defect mitigation

    NASA Astrophysics Data System (ADS)

    Liddell, Heather P. H.

    2014-05-01

    The laser-damage resistance of multilayer-dielectric (MLD) pulse compressor gratings currently limits the energy performance of the petawatt-class OMEGA EP laser system at University of Rochester's Laboratory for Laser Energetics. The cleanliness of these components is of paramount importance; contaminants can act as absorbers during laser irradiation, initiating intense local heating and catastrophic laser-induced damage. Unfortunately, some of the most effective cleaning methods for MLD gratings - usually involving high temperatures and strong acids or bases - can themselves induce chemical degradation and thermal stresses, leading to coating delamination and defects. This work explores ways to improve the laser-damage resistance of MLD gratings through modifications to the final cleaning phase of the manufacturing process. Processes of defect formation are investigated through a combination of chemical cleaning experiments, microscopy, and modeling. We use a fracture-mechanics approach to formulate a mechanism for the initiation of micrometer-scale delamination defects that are commonly observed after chemical cleaning. The stress responses of MLD coatings to elevated-temperature chemical cleaning are estimated using a thermomechanical model, enabling us to study the effects of substrate thickness, solution temperature, and heating rates on coating stresses (and thus the risk of stress-induced failure). Finally, a low-temperature chemical cleaning approach is developed to improve laser-damage resistance while avoiding defect formation and mitigating coating stresses. We find that grating coupons cleaned using the optimized method consistently meet OMEGA EP requirements on diffraction efficiency and 1054-nm laser-damage resistance at 10 ps.

  8. Correlated Strontium and Barium Isotopic Compositions of Acid-cleaned Single Mainstream Silicon Carbides from Murchison

    NASA Astrophysics Data System (ADS)

    Liu, Nan; Savina, Michael R.; Gallino, Roberto; Davis, Andrew M.; Bisterzo, Sara; Gyngard, Frank; Käppeler, Franz; Cristallo, Sergio; Dauphas, Nicolas; Pellin, Michael J.; Dillmann, Iris

    2015-04-01

    We present strontium, barium, carbon, and silicon isotopic compositions of 61 acid-cleaned presolar SiC grains from Murchison. Comparison with previous data shows that acid washing is highly effective in removing both strontium and barium contamination. For the first time, by using correlated 88Sr/86Sr and 138Ba/136Ba ratios in mainstream SiC grains, we are able to resolve the effect of 13C concentration from that of 13C-pocket mass on s-process nucleosynthesis, which points toward the existence of large 13C pockets with low 13C concentrations in asymptotic giant branch stars. The presence of such large 13C pockets with a variety of relatively low 13C concentrations seems to require multiple mixing processes in parent asymptotic giant branch stars of mainstream SiC grains.

  9. Advanced hot gas cleaning system for coal gasification processes

    NASA Astrophysics Data System (ADS)

    Newby, R. A.; Bannister, R. L.

    1994-04-01

    The United States electric industry is entering a period where growth and the aging of existing plants will mandate a decision on whether to repower, add capacity, or do both. The power generation cycle of choice, today, is the combined cycle that utilizes the Brayton and Rankine cycles. The combustion turbine in a combined cycle can be used in a repowering mode or in a greenfield plant installation. Today's fuel of choice for new combined cycle power generation is natural gas. However, due to a 300-year supply of coal within the United States, the fuel of the future will include coal. Westinghouse has supported the development of coal-fueled gas turbine technology over the past thirty years. Working with the U.S. Department of Energy and other organizations, Westinghouse is actively pursuing the development and commercialization of several coal-fueled processes. To protect the combustion turbine and environment from emissions generated during coal conversion (gasification/combustion) a gas cleanup system must be used. This paper reports on the status of fuel gas cleaning technology and describes the Westinghouse approach to developing an advanced hot gas cleaning system that contains component systems that remove particulate, sulfur, and alkali vapors. The basic process uses ceramic barrier filters for multiple cleaning functions.

  10. Studies on the production of ultra-clean coal by alkali-acid leaching of low-grade coals

    SciTech Connect

    Nabeel, A.; Khan, T.A.; Sharma, D.K.

    2009-07-01

    The use of low-grade coal in thermal power stations is leading to environmental pollution due to the generation of large amounts of fly ash, bottom ash, and CO{sub 2} besides other pollutants. It is therefore important to clean the coal before using it in thermal power stations, steel plants, or cement industries etc. Physical beneficiation of coal results in only limited cleaning of coal. The increasing environmental pollution problems from the use of coal have led to the development of clean coal technologies. In fact, the clean use of coal requires the cleaning of coal to ultra low ash contents, keeping environmental norms and problems in view and the ever-growing need to increase the efficiency of coal-based power generation. Therefore this requires the adaptation of chemical cleaning techniques for cleaning the coal to obtain ultra clean coal having ultra low ash contents. Presently the reaction conditions for chemical demineralization of low-grade coal using 20% aq NaOH treatment followed by 10% H{sub 2}SO{sub 4} leaching under reflux conditions have been optimized. In order to reduce the concentration of alkali and acid used in this process of chemical demineralization of low-grade coals, stepwise, i.e., three step process of chemical demineralization of coal using 1% or 5% aq NaOH treatment followed by 1% or 5% H{sub 2}SO{sub 4} leaching has been developed, which has shown good results in demineralization of low-grade coals. In order to conserve energy, the alkali-acid leaching of coal was also carried out at room temperature, which gave good results.

  11. CORROSION TESTING OF CARBON STEEL IN OXALIC ACID CHEMICAL CLEANING SOLUTIONS

    SciTech Connect

    Wiersma, B.; Mickalonis, J.; Subramanian, K.; Ketusky, E.

    2011-10-14

    Radioactive liquid waste has been stored in underground carbon steel tanks for nearly 60 years at the Savannah River Site. The site is currently in the process of removing the waste from these tanks in order to place it into vitrified, stable state for longer term storage. The last stage in the removal sequence is a chemical cleaning step that breaks up and dissolves metal oxide solids that cannot be easily pumped out of the tank. Oxalic acid has been selected for this purpose because it is an effective chelating agent for the solids and is not as corrosive as other acids. Electrochemical and immersion studies were conducted to investigate the corrosion behavior of carbon steel in simulated chemical cleaning environments. The effects of temperature, agitation, and the presence of sludge solids in the oxalic acid on the corrosion rate and the likelihood of hydrogen evolution were determined. The testing showed that the corrosion rates decreased significantly in the presence of the sludge solids. Corrosion rates increased with agitation, however, the changes were less noticeable.

  12. IN-SITU MONITORING OF CORROSION DURING A LABORATORY SIMULATION OF OXALIC ACID CHEMICAL CLEANING

    SciTech Connect

    Wiersma, B; John Mickalonis, J; Michael Poirier, M; John Pareizs, J; David Herman, D; David Beam, D; Samuel Fink, S; Fernando Fondeur, F

    2007-10-08

    The Savannah River Site (SRS) will disperse or dissolve precipitated metal oxides as part of radioactive waste tank closure operations. Previously SRS used oxalic acid to accomplish this task. To better understand the conditions of oxalic acid cleaning of the carbon steel waste tanks, laboratory simulations of the process were conducted to determine the corrosion rate of carbon steel and the generation of gases such as hydrogen and carbon dioxide. Open circuit potential measurements, linear polarization measurements, and coupon immersion tests were performed in-situ to determine the corrosion behavior of carbon steel during the demonstration. Vapor samples were analyzed continuously to determine the constituents of the phase. The combined results from these measurements indicated that in aerated environments, such as the tank, that the corrosion rates are manageable for short contact times and will facilitate prediction and control of the hydrogen generation rate during operations.

  13. Two-Step Plasma Process for Cleaning Indium Bonding Bumps

    NASA Technical Reports Server (NTRS)

    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.

  14. Copper post-CMP cleaning process on a dry-in/dry-out tool

    NASA Astrophysics Data System (ADS)

    Basak, Sanjay; Grief, Malcolm; Gupta, Anand; Murella, Krishna; VanDevender, Barrie

    1998-09-01

    Metal Chemical Mechanical Planarization (CMP) and post CMP cleaning have continued to increase in importance in semiconductor manufacturing. The introduction of copper metallization into semiconductor manufacturing processes has created a need for integrating CMP and cleaning tools, as well as a demand for the development of novel cleaning solutions. One system designed for integrated CMP processing and cleaning, commonly referred to as dry-in/dry-out CMP, is the SpeedFam Auriga C. The Auriga C integrates a widely used polishing tool together with a proven cleaning technique. The key to the operation of the Auriga C cleaning process is the effective operation of the PVA brush cleaners, water track transport, final jet rinse and high-speed spinner dryer. The effective operation of the cleaning mechanism for copper post- CMP cleaning requires the use of new chemical solutions. Typical solutions used for post process cleaning of more mature CMP processes are either ineffective for cleaning or chemically incompatible with the copper process. This paper discusses the cleaning mechanism used in an integrated dry- in/dry-out tool and demonstrates an effective and novel cleaning solution for use with this type of post-CMP cleaning process.

  15. Optimization of clean fractionation processing as a pre-treatment technology for prairie cordgrass.

    PubMed

    Brudecki, Grzegorz; Cybulska, Iwona; Rosentrater, Kurt; Julson, James

    2012-03-01

    The main objective of this study was to fractionate prairie cordgrass (PCG) obtaining the highest cellulose digestibility. Following clean fractionation (CF) processing, the PCG lignocellulosic biomass was fractionated into three main building blocks: cellulose, hemicellulose and lignin. Effects of processing factors such as time, temperature, catalyst concentration and organic solvent mixture composition were evaluated. Organic solvent-aqueous mixture contained methyl isobutyl ketone (MIBK), ethanol and water in different proportions. Sulfuric acid was used as a catalyst. In order to evaluate the degree of pre-treatment, enzymatic saccharification was employed on the cellulose fraction obtained from the CF process. Response surface methodology was used for process optimization and statistical analysis. Optimal conditions (39 min, 154°C, 0.69% catalyst and 9% MIBK) resulted in 84% glucose yield and 87% acid insoluble lignin (AIL). PMID:22244901

  16. ENVIRONMENTAL ASSESSMENT OF COAL CLEANING PROCESSES: HOMER CITY POWER COMPLEX TESTING

    EPA Science Inventory

    The report describes a preliminary, preoperational environmental survey conducted at a newly constructed advanced physical coal cleaning plant near Homer City, PA. The work is part of a comprehensive environmental assessment of physical and chemical coal cleaning processes perfor...

  17. Determination of fusaric acid in maize using molecularly imprinted SPE clean-up

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new liquid chromatography method to detect fusaric acid in maize is reported based on molecularly imprinted polymer solid phase extraction clean-up (MISPE) using mimic-templated molecularly-imprinted polymers. Picolinic acid was used as a toxin analog for imprinting polymers during a thermolytic s...

  18. Nucleic acid isolation process

    SciTech Connect

    Longmire, J.L.; Lewis, A.K.; Hildebrand, C.E.

    1990-05-01

    This patent describes a process for preparing DNA from cellular materials for use in genetic studies of eukaryotic systems, a process for isolating DNA fragments from proteolytic digestion products and detergent products in a solution with the DNA fragments produced in stripping undesired cellular constituents from the DNA. It comprises the step of dialyzing a solution containing the DNA fragments, detergent products, and proteolytic digestion products against a solution containing PEG for a time effective to yield DNA sufficiently pure of the genetic studies.

  19. Process for cleaning the inner walls of a reactor

    SciTech Connect

    Perrot, M.; Jaccaud, M.

    1985-05-21

    A physico-chemical cleaning process for the inner walls of a reactor which serves to maintain these walls in a state close to their main initial characteristics necessitated by a fluorination reaction, said characteristics being degraded by the deposition of a parasitic phase during the reaction, said initial characteristics being maintained by the use of a protective agent belonging to the group constituted by at least one of the reagents, a product resulting from the reaction, a product foreign to the reaction, but compatible with the substances of the main reaction or by the reaction of a third substance with at least one of the reaction substances or a mixture thereof, forming a renewable protective film on the said walls. The protective agent can be deposited by condensation on the walls before, during or after the main reaction, and then vaporized. The protective agent can be in liquid form, and trickling along the walls.

  20. Implications of the Clean Air Act acid rain title on industrial boilers

    SciTech Connect

    Maibodi, M. )

    1991-11-01

    This paper discusses the impacts of the 1990 Clean Air Act Amendments related to acid rain controls, as they apply to industrial boilers. Emphasis is placed on explaining the Title IV provisions of the Amendments that permit nonutility sources to participate in the SO{sub 2} allowance system. The allowance system, as it pertains to industrial boiler operators, is described, and the opportunities for operators to trade and/or sell SO{sub 2} emission credits is discussed. The paper also reviews flue gas desulfurization system technologies available for industrial boiler operators who may choose to participate in the system. Furnace sorbent injection, advanced silicate process, lime spray drying, dry sorbent injection, and limestone scrubbing are described, including statements of their SO{sub 2} removing capability, commercial status, and costs. Capital costs, levelized costs and cost-effectiveness are presented for these technologies.

  1. Nucleic acid isolation process

    DOEpatents

    Longmire, Jonathan L.; Lewis, Annette K.; Hildebrand, Carl E.

    1990-01-01

    A method is provided for isolating DNA from eukaryotic cell and flow sorted chromosomes. When DNA is removed from chromosome and cell structure, detergent and proteolytic digestion products remain with the DNA. These products can be removed with organic extraction, but the process steps associated with organic extraction reduce the size of DNA fragments available for experimental use. The present process removes the waste products by dialyzing a solution containing the DNA against a solution containing polyethylene glycol (PEG). The waste products dialyze into the PEG leaving isolated DNA. The remaining DNA has been prepared with fragments containing more than 160 kb. The isolated DNA has been used in conventional protocols without affect on the protocol.

  2. SAVANNAH RIVER SITE TANK CLEANING: CORROSION RATE FOR ONE VERSUS EIGHT PERCENT OXALIC ACID SOLUTION

    SciTech Connect

    Ketusky, E.; Subramanian, K.

    2011-01-20

    Until recently, the use of oxalic acid for chemically cleaning the Savannah River Site (SRS) radioactive waste tanks focused on using concentrated 4 and 8-wt% solutions. Recent testing and research on applicable dissolution mechanisms have concluded that under appropriate conditions, dilute solutions of oxalic acid (i.e., 1-wt%) may be more effective. Based on the need to maximize cleaning effectiveness, coupled with the need to minimize downstream impacts, SRS is now developing plans for using a 1-wt% oxalic acid solution. A technology gap associated with using a 1-wt% oxalic acid solution was a dearth of suitable corrosion data. Assuming oxalic acid's passivation of carbon steel was proportional to the free oxalate concentration, the general corrosion rate (CR) from a 1-wt% solution may not be bound by those from 8-wt%. Therefore, after developing the test strategy and plan, the corrosion testing was performed. Starting with the envisioned process specific baseline solvent, a 1-wt% oxalic acid solution, with sludge (limited to Purex type sludge-simulant for this initial effort) at 75 C and agitated, the corrosion rate (CR) was determined from the measured weight loss of the exposed coupon. Environmental variations tested were: (a) Inclusion of sludge in the test vessel or assuming a pure oxalic acid solution; (b) acid solution temperature maintained at 75 or 45 C; and (c) agitation of the acid solution or stagnant. Application of select electrochemical testing (EC) explored the impact of each variation on the passivation mechanisms and confirmed the CR. The 1-wt% results were then compared to those from the 8-wt%. The immersion coupons showed that the maximum time averaged CR for a 1-wt% solution with sludge was less than 25-mils/yr for all conditions. For an agitated 8-wt% solution with sludge, the maximum time averaged CR was about 30-mils/yr at 50 C, and 86-mils/yr at 75 C. Both the 1-wt% and the 8-wt% testing demonstrated that if the sludge was removed from

  3. Experimental investigation of fabrication process-, transportation-, storage, and handling-induced contamination of 157-nm reticles and vacuum UV cleaning

    NASA Astrophysics Data System (ADS)

    Okoroanyanwu, Uzodinma; Stepanenko, Nickolay; Vereecke, Guy; Eliat, Astrid; Kocsis, Michael K.; Kang, Young-Seog; Jonckheere, Rik M.; Conard, Thierry; Ronse, Kurt G.

    2004-05-01

    Mask fabrication process, transportation, storage, and handling contribute to contamination of 157nm reticles and modified fused silica substrates, resulting in transmission loss. A stable VUV cleaning procedure for contaminated binary, alternating, and attenuated phase shift reticles has been developed. This cleaning procedure was verified by lithographic imaging on the 157nm ASML MS-VII exposure scanner. A point-to-point steady state dose transmission uniformity range across a batch of 25 wafers (the exposure conditions of which were equivalent to that of a 300 mm wafer, 26mm×33mm fields, 50mJ/cm2) that were exposed with a modified fused silica substrate, was found to be <0.24% for a reticle that was cleaned prior to exposure using this VUV cleaning process. In-situ laser cleaning of contaminated mask substrates during exposure in the MS-VII resulted in 1% change in transmission at doses of up to 20 J/cm2, above which transmission remains stable (<0.24% variation). The cleaning procedure involves exposing the contaminated reticle in the UVO Reticle Cleaning Station for 30 minutes, using a cleaning gas mixture of N2/O2=99%/1%. Transmission loss due to contamination within the clean room is limited to 1 - 2 % and is reversible upon VUV cleaning. Flare levels of 3% were measured on contaminated reticle relative to a clean state of the same reticle. VUV cleaning is not only good for improving and maintaining stable mask transmission, but it is also good for preventing reticle contamination-induced flare. Contamination rate and contaminant type appear to be dependent on the storage environment of mask substrates and reticles. Typical contaminants included molecular acids (halogens, sulfur, sulfates), molecular bases (ammonia, amines), molecular condensables (hydrocarbons, alcohols, ketones, fatty acids, siloxanes, phthalate), molecular dopant (boron) and molecular metals (Ca, Mg, Al, Cu). Contamination of mask substrates appears to be through a competitive adsorption

  4. Diethylaminoethyl-cellulose clean-up of a large volume naphthenic acid extract.

    PubMed

    Frank, Richard A; Kavanagh, Richard; Burnison, B Kent; Headley, John V; Peru, Kerry M; Der Kraak, Glen Van; Solomon, Keith R

    2006-08-01

    The Athabasca oil sands of Alberta, Canada contain an estimated 174 billion barrels of bitumen. During oil sands refining processes, an extraction tailings mixture is produced that has been reported as toxic to aquatic organisms and is therefore collected in settling ponds on site. Investigation into the toxicity of these tailings pond waters has identified naphthenic acids (NAs) and their sodium salts as the major toxic components, and a multi-year study has been initiated to identify the principal toxic components within NA mixtures. Future toxicity studies require a large volume of a NA mixture, however, a well-defined bulk extraction technique is not available. This study investigated the use of a weak anion exchanger, diethylaminoethyl-cellulose (DEAE-cellulose), to remove humic-like material present after collecting the organic acid fraction of oil sands tailings pond water. The NA extraction and clean-up procedure proved to be a fast and efficient method to process large volumes of tailings pond water, providing an extraction efficiency of 41.2%. The resulting concentrated NA solution had a composition that differed somewhat from oil sands fresh tailings, with a reduction in the abundance of lower molecular weight NAs being the most significant difference. This reduction was mainly due to the initial acidification of tailings pond water. The DEAE-cellulose treatment had only a minor effect on the NA concentration, no noticeable effect on the NA fingerprint, and no significant effect on the mixture toxicity towards Vibrio fischeri. PMID:16469358

  5. Oxalic acid adsorption states on the clean Cu(110) surface

    NASA Astrophysics Data System (ADS)

    Fortuna, Sara

    2016-11-01

    Carboxylic acids are known to assume a variety of configurations on metallic surfaces. In particular oxalic acid on the Cu(110) surface has been proposed to assume a number of upright configurations. Here we explore with DFT calculations the possible structures that oxalic acid can form on copper 110 at different protonation states, with particular attention at the possibility of forming structures composed of vertically standing molecules. In its fully protonated form it is capable of anchoring itself on the surface thanks to one of its hydrogen-free oxygens. We show the monodeprotonated upright molecule with two oxygens anchoring it on the surface to be the lowest energy conformation of a single oxalic molecules on the Cu(110) surface. We further show that it is possible for this configuration to form dense hexagonally arranged patterns in the unlikely scenario in which adatoms are not involved.

  6. Crude oil tank-cleaning process recovers oil, reduces hazardous wastes

    SciTech Connect

    Davis, G.B. ); Goss, M.L. ); Schoemann, P.; Tyler, S.S. )

    1993-12-13

    An improved crude oil tank-cleaning process can reduce hazardous waste generated from tank bottoms and allow the recovery of valuable hydrocarbons. The process uses chemicals, heat, water, and applications technology. Crude oil tank bottoms are typically high in hydrocarbons -- a valuable raw material if recovered and recycled back to the refining process. Nalco's patented program essentially separates sludge into its components: water, nonhazardous solids, and recovered hydrocarbons. The paper describes industry trends, sludge removal, mechanical cleaning, chemical cleaning, environment and safety, case history of a New Jersey refinery, testing, program design, the cleaning process, hydrocarbon recovery, and return on investment.

  7. Evaluation of no-clean solder process designed to eliminate the use of ozone-depleting chemicals

    SciTech Connect

    Paffett, M.T.; Farr, J.D.; Rogers, Y.C.; Hutchinson, W.B.

    1993-10-01

    This paper summarizes the LANL contributions to a joint Motorola/SNLA/LANL cooperative research and development agreement study on the reliability of an alternative solder process that is intended to reduce or eliminate the use of ozone-depleting chemicals in the manufacture of printed wire boards (PWBs). This process is termed self-cleaning because of the nature of the thermal chemistry associated with the adipic and formic acid components used in place of traditional solder rosin fluxes. Traditional rosin fluxes used in military electronic hardware applications are cleaned (by requirement) using chlorofluorohydrocarbons. The LANL contribution centers around analytical determination of PWB cleanliness after soldering using the self-cleaning method. Results of these analytical determinations involving primarily surface analysis of boards following temperature, temperature and humidity, and long-term storage testing are described with representative data. It is concluded that the self-cleaning process leaves behind levels of solid residue that are visually and analytically observable using most of these surface analysis techniques. The materials compatibility of electronic components soldered using the self-cleaning soldering process is more fully described in the project report issued by SNLA that encompasses the complete project with statistical lifetime and accelerated aging studies. Analytical surface specificity and suggestions for further work are also given.

  8. Development of a replacement for trichloroethylene in the two-stage cleaning process

    SciTech Connect

    Harding, W.B.

    1992-12-01

    A solvent was sought to replace trichloroethylene in the two-stage cleaning process that is used in the Allied-Signal Inc., Kansas City Division (KCD) Miniature Electro-Mechanical Assembly Department. The process is an ultrasonic cleaning process in which product is first cleaned in trichloroethylene and then in isopropyl alcohol. After a general review of the properties of available solvents, isopropyl alcohol, d-limonene, and a synthetic mineral spirits, were chosen to be evaluated as trichloroethylene replacements. Stainless steel test panels were cleaned and then soiled with several different organic materials. Certain of the panels were cleaned by the two-stage process. The others were cleaned by the two-stage process using one or another of the solvents under evaluation in the place of the trichloroethylene. The cleanliness of the panels was determined by Auger and photoelectron spectroscopy. The panels cleaned with any of the three solvents under evaluation were found to be as clean as those cleaned by the standard two-stage process. Because of simplicity and minimization of inventory, it is recommended that the two-stage process be changed to use isopropyl alcohol in both stages.

  9. Towards a better hydraulic cleaning strategy for ultrafiltration membrane fouling by humic acid: Effect of backwash water composition.

    PubMed

    Chang, Haiqing; Liang, Heng; Qu, Fangshu; Ma, Jun; Ren, Nanqi; Li, Guibai

    2016-05-01

    As a routine measurement to alleviate membrane fouling, hydraulic cleaning is of great significance for the steady operation of ultrafiltration (UF) systems in water treatment processes. In this work, a comparative study was performed to investigate the effects of the composition of backwash water on the hydraulic cleaning performance of UF membranes fouled by humic acid (HA). Various types of backwash water, including UF permeate, Milli-Q water, NaCl solution, CaCl2 solution and HA solution, were compared in terms of hydraulically irreversible fouling index, total surface tension and residual HA. The results indicated that Milli-Q water backwash was superior to UF permeate backwash in cleaning HA-fouled membranes, and the backwash water containing Na(+) or HA outperformed Milli-Q water in alleviating HA fouling. On the contrary, the presence of Ca(2+) in backwash water significantly decreased the backwash efficiency. Moreover, Ca(2+) played an important role in foulant removal, and the residual HA content closely related to the residual Ca(2+) content. Mechanism analysis suggested that the backwash process may involve fouling layer swelling, ion exchange, electric double layer release and competitive complexation. Ion exchange and competitive complexation played significant roles in the efficient hydraulic cleaning associated with Na(+) and HA, respectively. PMID:27155423

  10. Development and testing of a low toxicity acid corrosion inhibitor for industrial cleaning applications

    SciTech Connect

    Frenier, W.W.

    1997-02-01

    A low toxicity corrosion inhibitor used in hydrochloric acid cleaning formulations has been developed. This formulation does not contain formaldehyde. It contains cinnamaldehyde, quaternary nitrogen salts, and a nonionic surfactant, none of which are currently known or suspected to be carcinogens. In laboratory tests, corrosion protection values were equivalent to those provided by current commercial acid inhibitors. Field tests using the low toxicity inhibitor were conducted.

  11. Development of the chemical and electrochemical coal cleaning (CECC) process. Final report

    SciTech Connect

    Yoon, Roe-Hoan; Basilio, C.I.

    1992-05-01

    The Chemical and Electrochemical Coal Cleaning (CECC) process developed at Virginia Polytechnic Institute and State University was studied further in this project. This process offers a new method of physically cleaning both low- and high-rank coals without requiring fine grinding. The CECC process is based on liberating mineral matter from coal by osmotic pressure. The majority of the work was conducted on Middle Wyodak, Pittsburgh No. 8 and Elkhorn No. 3 coals. The coal samples were characterized for a variety of physical and chemical properties. Parametric studies were then conducted to identify the important operating parameters and to establish the optimum conditions. In addition, fundamental mechanisms of the process were studied, including mineral matter liberation, kinetics of mineral matter and pyrite dissolution, ferric ion regeneration schemes and alternative methods of separating the cleaned coal from the liberated mineral matter. The information gathered from the parametric and fundamental studies was used in the design, construction and testing of a bench-scale continuous CECC unit. Using this unit, the ash content of a Middle Wyodak coal was reduced from 6.96 to 1.61% at a 2 lbs/hr throughput. With an Elkhorn No. 3 sample, the ash content was reduced from 9.43 to 1.8%, while the sulfur content was reduced from 1.57 to 0.9%. The mass balance and liberation studies showed that liberation played a more dominant role than the chemical dissolution in removing mineral matter and inorganic sulfur from the different bituminous coals tested. However, the opposite was found to be the case for the Wyodak coal since this coal contained a significant amount of acid-soluble minerals.

  12. Established techniques for cleaning depleted-uranium derby in lieu of nitric acid pickling. Contractor report (Final)

    SciTech Connect

    Letham-Brown, C.E.; Vanderkooi, D.

    1987-05-01

    The work described in this report details a method for the surface cleaning of depleted uranium derby by means of high-pressure water in lieu of nitric acid. The benefits realized are a more thorough cleaning, no loss of metal by pickling, elimination of hazardous handling, and disposal of spent-acid solutions.

  13. Process for forming sulfuric acid

    DOEpatents

    Lu, Wen-Tong P.

    1981-01-01

    An improved electrode is disclosed for the anode in a sulfur cycle hydrogen generation process where sulfur dioxie is oxidized to form sulfuric acid at the anode. The active compound in the electrode is palladium, palladium oxide, an alloy of palladium, or a mixture thereof. The active compound may be deposited on a porous, stable, conductive substrate.

  14. DEPOSITION TANK CORROSION TESTING FOR ENHANCED CHEMICAL CLEANING POST OXALIC ACID DESTRUCTION

    SciTech Connect

    Mickalonis, J.

    2011-08-29

    An Enhanced Chemical Cleaning (ECC) process is being developed to aid in the high level waste tank closure at the Savannah River Site. The ECC process uses an advanced oxidation process (AOP) to destroy the oxalic acid that is used to remove residual sludge from a waste tank prior to closure. The AOP process treats the dissolved sludge with ozone to decompose the oxalic acid through reactions with hydroxyl radicals. The effluent from this oxalic acid decomposition is to be sent to a Type III waste tank and may be corrosive to these tanks. As part of the hazardous simulant testing that was conducted at the ECC vendor location, corrosion testing was conducted to determine the general corrosion rate for the deposition tank and to assess the susceptibility to localized corrosion, especially pitting. Both of these factors impact the calculation of hydrogen gas generation and the structural integrity of the tanks, which are considered safety class functions. The testing consisted of immersion and electrochemical testing of A537 carbon steel, the material of construction of Type III tanks, and 304L stainless steel, the material of construction for transfer piping. Tests were conducted in solutions removed from the destruction loop of the prototype ECC set up. Hazardous simulants, which were manufactured at SRNL, were used as representative sludges for F-area and H-area waste tanks. Oxalic acid concentrations of 1 and 2.5% were used to dissolve the sludge as a feed to the ECC process. Test solutions included the uninhibited effluent, as well as the effluent treated for corrosion control. The corrosion control options included mixing with an inhibited supernate and the addition of hydroxide. Evaporation of the uninhibited effluent was also tested since it may have a positive impact on reducing corrosion. All corrosion testing was conducted at 50 C. The uninhibited effluent was found to increase the corrosion rate by an order of magnitude from less than 1 mil per year (mpy

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

    SciTech Connect

    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{sup 22} and 10{sup 23} photons per meter for a PSD measurement. Desorption yields for H{sub 2}, CO, CO{sub 2}, CH{sub 4} and H{sub 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.

  16. Development of a cleaning process for uranium chips machined with a glycol-water-borax coolant

    SciTech Connect

    Taylor, P.A.

    1984-12-01

    A chip-cleaning process has been developed to remove the new glycol-water-borax coolant from oralloy chips. The process involves storing the freshly cut chips in Freon-TDF until they are cleaned, washing with water, and displacing the water with Freon-TDF. The wash water can be reused many times and still yield clean chips and then be added to the coolant to make up for evaporative losses. The Freon-TDF will be cycled by evaporation. The cleaning facility is currently being designed and should be operational by April 1985.

  17. Type 304L stainless steel surface microstructure: Performance in hydride storage and acid cleaning

    SciTech Connect

    Clark, E.A.

    1994-07-01

    The performance of stainless steel as the container in hydride storage bed systems has been evaluated, primarily using scanning electron microscopy. No adverse reaction between Type 304L stainless steel and either LaNi{sub 5{minus}x},Al{sub x}, or palladium supported on Kieselguhr granules (silica) during exposure in hydrogen was found in examination of retired prototype storage bed containers and special compatibility test samples. Intergranular surface ditching, observed on many of the stainless steel surfaces examined, was shown to result from air annealing and acid cleaning of stainless steel during normal fabrication. The ditched air annealed and acid cleaned stainless steel samples were more resistant to subsequent acid attack than vacuum annealed or polished samples without ditches.

  18. Process of cleaning oil spills and the like

    SciTech Connect

    Breisford, J.A.

    1993-06-01

    A process of cleaning spills of toxic or hazardous materials such as oil, antifreeze, gasoline, and the like from bodies of water, garage floors, roadways and the like, comprising spraying unbonded shredded fiberglass blowing wool composition particles onto the spill, absorbing the spill into the shredded fiberglass blowing wool composition particles, and removing the soaked shredded fiberglass blowing wool composition particles and the spill absorbed therein. An absorbent composition for absorbing spills of toxic or hazardous materials such as oil, antifreeze, gasoline, and like, comprising shredded fiberglass blowing wool particles, and means for absorbing the spill and for stiffening the co-position so that the composition fights against being compressed so that less of the absorbed spill escapes from the composition when it is being removed from the spill, said means including cork particles dispersed in with the fiberglass blowing wool particles. An absorbent sock for absorbing or containing a spill of toxic or hazardous materials such as oil, antifreeze, gasoline, and the like, comprising a hollow tube, said tube being permeable to the toxic or hazardous materials and being made of nylon or polypropylene, and unbonded, shredded fiberglass blowing wool composition particles enclosed in the tube. Apparatus for controlling an oil slick on the surface of water, comprising a craft for traversing the slick, a supply of fiberglass blowing wool composition particles stored on the craft in position for being dispersed, shredding means on the craft for shredding the fiberglass blowing wool particles to form unbonded, shredded fiberglass blowing wool particles, and dispensing means on the craft for dispensing the unbonded, shredded fiberglass blowing wool particles onto the slick.

  19. Retrospective Clinical Trial of Fusidic Acid versus Petrolatum in the Postprocedure Care of Clean Dermatologic Procedures

    PubMed Central

    Lee, Dong Hun; Kim, Dong Young; Yoon, So Young; Park, Hyun Sun; Yoon, Hyun-Sun

    2015-01-01

    Background Clean dermatologic procedures create wounds with a low risk of infection (usually up to 5%). Whether the use of topical antibiotics is advocated, with regard to its efficacy and safety issues such as antibiotic resistance and sensitizing potential, is controversial. Fusidic acid, a topical antibiotic against gram-positive bacteria, is a rare sensitizer and commonly used in postprocedure care in Korea. Objective This is a retrospective study aimed at comparing the efficacy and safety between fusidic acid and petrolatum for the postprocedure care of clean dermatologic procedures. Methods Patients were treated with either fusidic acid or petrolatum ointment, applied on the wound created during clean dermatologic procedures such as biopsy of the punch, incisional, excisional, and shave types. The efficacy, adverse events, and subjective level of satisfaction were retrieved from medical records. Results A total of 414 patients with a total of 429 wounds were enrolled. The overall rate of adverse events was 0.9%, and the rates of adverse events in the fusidic acid group and the petrolatum group were 1.4% and 0.5%, respectively (p=0.370). There was no wound discharge, pain, tenderness, swelling, induration, or dehiscence in both groups. The patients' self-assessment of the wound was not significantly different between the two treatment groups. Conclusion Our findings support the hypothesis that the routine prophylactic use of topical antibiotics is not indicated for clean dermatologic procedures. We recommend the use of petrolatum in the postoperative care of clean dermatologic procedures because of its equivalent efficacy and superior safety profiles. PMID:25673926

  20. The microbial ecology of processing equipment in different fish industries-analysis of the microflora during processing and following cleaning and disinfection.

    PubMed

    Bagge-Ravn, Dorthe; Ng, Yin; Hjelm, Mette; Christiansen, Jesper N; Johansen, Charlotte; Gram, Lone

    2003-11-01

    The microflora adhering to the processing equipment during production and after cleaning and disinfecting procedures was identified in four different processing plants. A total of 1009 microorganisms was isolated from various-agar plates and identified. A stepwise procedure using simple phenotypic tests was used to identify the isolates and proved a fast way to group a large collection of microorganisms. Pseudomonas, Neisseriaceae, Enterobactericeae, Coryneform, Acinetobacter and lactic acid bacteria dominated the microflora of cold-smoked salmon plants, whereas the microflora in a plant processing semi-preserved herring consisted of Pseudomonas, Alcaligenes and Enterobactericeae. Psychrobacter, Staphylococcus and yeasts were found in a caviar processing plant. Overall, many microorganisms that are often isolated from fish were also isolated from the fish processing plants. However, some selection depending on processing parameters occurred, since halo- and osmo-tolerant organisms dominated in the caviar processing. After cleaning and disinfection, yeasts, Pseudomonas, Neisseriaceae and Alcaligenes remained in smokehouses, yeasts and Pseudomonas in the herring plant and Pseudomonas, Staphylococcus and yeasts in the caviar plant. The dominant adhering organisms after cleaning and disinfection were pseudomonads and yeasts independently of the microflora during processing. Knowledge of the adhering microflora is essential in the Good Hygienic Practises programme of food processing plants, as the development and design of improved cleaning and disinfecting procedures should target the microorganisms persisting and potentially contaminating the product. PMID:14527796

  1. Precision Cleaning and Verification Processes Used at Marshall Space Flight Center for Critical Hardware Applications

    NASA Technical Reports Server (NTRS)

    Caruso, Salvadore V.

    1999-01-01

    Marshall Space Flight Center (MSFC) of the National Aeronautics and Space Administration (NASA) performs many research and development programs that require hardware and assemblies to be cleaned to levels that are compatible with fuels and oxidizers (liquid oxygen, solid propellants, etc.). Also, the Center is responsible for developing large telescope satellites which requires a variety of optical systems to be cleaned. A precision cleaning shop is operated with-in MSFC by the Fabrication Services Division of the Materials & Processes Division. Verification of cleanliness is performed for all precision cleaned articles in the Analytical Chemistry Branch. Since the Montreal Protocol was instituted, MSFC had to find substitutes for many materials that has been in use for many years, including cleaning agents and organic solvents. As MSFC is a research Center, there is a great variety of hardware that is processed in the Precision Cleaning Shop. This entails the use of many different chemicals and solvents, depending on the nature and configuration of the hardware and softgoods being cleaned. A review of the manufacturing cleaning and verification processes, cleaning materials and solvents used at MSFC and changes that resulted from the Montreal Protocol will be presented.

  2. Precision Cleaning and Verification Processes Used at Marshall Space Flight Center for Critical Hardware Applications

    NASA Technical Reports Server (NTRS)

    Caruso, Salvadore V.; Cox, Jack A.; McGee, Kathleen A.

    1998-01-01

    Marshall Space Flight Center (MSFC) of the National Aeronautics and Space Administration performs many research and development programs that require hardware and assemblies to be cleaned to levels that are compatible with fuels and oxidizers (liquid oxygen, solid propellants, etc.). Also, MSFC is responsible for developing large telescope satellites which require a variety of optical systems to be cleaned. A precision cleaning shop is operated within MSFC by the Fabrication Services Division of the Materials & Processes Laboratory. Verification of cleanliness is performed for all precision cleaned articles in the Environmental and Analytical Chemistry Branch. Since the Montreal Protocol was instituted, MSFC had to find substitutes for many materials that have been in use for many years, including cleaning agents and organic solvents. As MSFC is a research center, there is a great variety of hardware that is processed in the Precision Cleaning Shop. This entails the use of many different chemicals and solvents, depending on the nature and configuration of the hardware and softgoods being cleaned. A review of the manufacturing cleaning and verification processes, cleaning materials and solvents used at MSFC and changes that resulted from the Montreal Protocol will be presented.

  3. NATO CCMS PILOT STUDY: CLEAN PRODUCTS AND PROCESSES - PHASE I: AN ASSESSMENT

    EPA Science Inventory

    Clean Products and Processes - promote cooperation for improving the common pollution landscape by stimulating cross-national dialogues and collaboration. Share knowledge on the methods, tools, and technologies for making cleaner products and processes possible.

  4. WATER AS A REACTION MEDIUM FOR CLEAN CHEMICAL PROCESSES.

    EPA Science Inventory

    Green chemistry is a rapid developing new field that provides us a pro-active avenue for the sustainable development of future science and technologies. When designed properly, clean chemical technology can be developed in water as a reaction media. The technologies generated f...

  5. The importance of cleaning for the overall results of processing endoscopes.

    PubMed

    Martiny, H; Floss, H; Zühlsdorf, B

    2004-04-01

    Reprocessing comprises three steps: cleaning, disinfection and-if required-sterilisation. While the extents of disinfection and of sterilisation are quantitatively defined, there are only imprecise (qualitative) definitions of cleaning. There are two main reasons for accurate cleaning. First organic and inorganic materials that remain on inner and outer surfaces will interfere with the efficacy of the disinfectants. In case of endoscopes this will lead to channel blockages; they remain undisinfected. Second the bioburden found on endoscopes after use can be very high. Data available demonstrate that a bacterial burden of up to 10(9)cfu/endoscope channel can be expected. Therefore it is necessary to perform a thorough cleaning. Studies using endoscopes showed a reduction in microbial counts by a factor of approximately 10(4) by cleaning (manual and mechanical). Therefore in 2001 the German Society of Hospital Hygiene (DGKH) specified its requirements and recommendations for determining cleaning efficacy separately from those for disinfection. Cleaning and disinfecting can be done manually or mechanically, but it seems impossible to validate manual processes. However our studies in two different washer-disinfectors (WD) showed differences in cleaning efficacy. The tested cleaning processes showed different efficacies. Not all cleaning processes showed better results than water alone with regard to visible cleanliness and to a microbiological reduction E. faecium. Our results show that the evaluation of cleanliness exclusively by visible inspection is not sufficient, particular for the lumens of endoscopes. The results also show that a cleaning process may be very effective also in reducing micro-organisms present. PMID:15110118

  6. 7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Seed in bulk or large quantities; seed for cleaning or... (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling in General § 201.33 Seed in bulk or large quantities; seed for cleaning or processing. (a) In the case of seed in bulk, the information required...

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

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Seed in bulk or large quantities; seed for cleaning or... (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling in General § 201.33 Seed in bulk or large quantities; seed for cleaning or processing. (a) In the case of seed in bulk, the information required...

  8. 7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Seed in bulk or large quantities; seed for cleaning or... (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling in General § 201.33 Seed in bulk or large quantities; seed for cleaning or processing. (a) In the case of seed in bulk, the information required...

  9. 7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Seed in bulk or large quantities; seed for cleaning or... (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling in General § 201.33 Seed in bulk or large quantities; seed for cleaning or processing. (a) In the case of seed in bulk, the information required...

  10. 7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Seed in bulk or large quantities; seed for cleaning or... (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling in General § 201.33 Seed in bulk or large quantities; seed for cleaning or processing. (a) In the case of seed in bulk, the information required...

  11. Evaluation of a no-clean soldering process designed to eliminate the use of ozone depleting chemicals

    SciTech Connect

    Iman, R.L.; Armendariz, M.E.; Anderson, D.J. |; Lichtenberg, L.; Van Buren, P.; Paffett, M.T.

    1992-11-01

    The destruction of the Earth`s protective ozone layer is one of today`s largest environmental concerns. Solvent emissions released during the cleaning of printed wiring boards (PWBs) have been identified as a primary contributor to ozone destruction. No-clean soldering (sometimes referred to as self-cleaning) processes represent an ideal solution since they eliminate the need for cleaning after soldering. Elimination of solvent cleaning operations significantly reduces the emissions of ozone depleting chemicals (ODCs), reduces energy consumption, and reduces product costs. Several no-clean soldering processes have been developed over the past few years. The program`s purpose was to evaluate the no-clean soldering process and to determine if hardware produced by the process is acceptable for military applications. That is, determine if the no-clean process produces hardware that is as reliable as that soldered with the existing rosin-based flux solvent cleaning process.

  12. Clean-air legislation will buoy U. S. gas processing

    SciTech Connect

    Haun, R.R.; Ellington, E.E.; Otto, K.W. )

    1991-07-22

    This paper reports on the effects of recent U.S. clean-air legislation on NGL demand and pricing. Demand for all NGL products will be firm throughout the 1990s. Increased requirements for butane as methyl tertiary butyl ether (MTBE) feedstock will strengthen butane prices. Higher base-load requirements for propane in new NGL-based olefin plants will also have a positive impact on propane prices.

  13. Development of CFC-Free Cleaning Processes at the NASA White Sands Test Facility

    NASA Technical Reports Server (NTRS)

    Beeson, Harold; Kirsch, Mike; Hornung, Steven; Biesinger, Paul

    1995-01-01

    The NASA White Sands Test Facility (WSTF) is developing cleaning and verification processes to replace currently used chlorofluorocarbon-113- (CFC-113-) based processes. The processes being evaluated include both aqueous- and solvent-based techniques. The presentation will include the findings of investigations of aqueous cleaning and verification processes that are based on a draft of a proposed NASA Kennedy Space Center (KSC) cleaning procedure. Verification testing with known contaminants, such as hydraulic fluid and commonly used oils, established correlations between nonvolatile residue and CFC-113. Recoveries ranged from 35 to 60 percent of theoretical. WSTF is also investigating enhancements to aqueous sampling for organics and particulates. Although aqueous alternatives have been identified for several processes, a need still exists for nonaqueous solvent cleaning, such as the cleaning and cleanliness verification of gauges used for oxygen service. The cleaning effectiveness of tetrachloroethylene (PCE), trichloroethylene (TCE), ethanol, hydrochlorofluorocarbon-225 (HCFC-225), tert-butylmethylether, and n-Hexane was evaluated using aerospace gauges and precision instruments and then compared to the cleaning effectiveness of CFC-113. Solvents considered for use in oxygen systems were also tested for oxygen compatibility using high-pressure oxygen autoignition and liquid oxygen mechanical impact testing.

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    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 activity

  15. Tunable droplet momentum and cavitation process for damage-free cleaning of challenging particles

    NASA Astrophysics Data System (ADS)

    Gouk, Roman; Papanu, James; Li, Fred; Jeon, Jason; Liu, Tong; Yalamanchili, Rao

    2008-10-01

    Particle removal without damage has been demonstrated for <60nm photomask sub-resolution assist features with droplet momentum cleaning technology that employs NanoDropletTM mixed-fluid jet nozzle. Although 99%+ particle removal efficiency can be achieved for standard Si3N4 particles with broad size distribution, there are some cleaning challenges with small (<100nm) and large contact area (>500nm) particles. It was found that tunable uniform cavitation can provide the additional physical assist force needed to improve cleaning efficiency of these challenging particles while meeting the damage-fee cleaning requirement. An integrated cleaning process was developed that combines both droplet momentum and damage-free cavitation technology. Cleaning tests were performed with different types of challenging particles. The results showed 5-8% particle removal efficiency improvement as compared to momentum based only cleaning. All masks were processed using the TetraTM mask cleaning tool configured with NanoDropletTM mixed fluid jet technology and full face megasonics.

  16. New geothermal heat extraction process to deliver clean power generation

    ScienceCinema

    Pete McGrail

    2012-12-31

    A new method for capturing significantly more heat from low-temperature geothermal resources holds promise for generating virtually pollution-free electrical energy. Scientists at the Department of Energys Pacific Northwest National Laboratory will determine if their innovative approach can safely and economically extract and convert heat from vast untapped geothermal resources. The goal is to enable power generation from low-temperature geothermal resources at an economical cost. In addition to being a clean energy source without any greenhouse gas emissions, geothermal is also a steady and dependable source of power.

  17. Development of a replacement for trichloroethylene in the two-stage cleaning process

    NASA Astrophysics Data System (ADS)

    Harding, W. B.

    1992-12-01

    Isopropyl alcohol, d-limonene, and a synthetic mineral spirits were compared for effectiveness as replacements for trichloroethylene in an ultrasonic cleaning process. All were found to be suitable. Isopropyl alcohol is recommended as the replacement.

  18. Study of discharge cleaning process in JIPP T-2 Torus by residual gas analyzer

    NASA Astrophysics Data System (ADS)

    Noda, N.; Hirokura, S.; Taniguchi, Y.; Tanahashi, S.

    1982-12-01

    During discharge cleaning, decay time of water vapor pressure changes when the pressure reaches a certain level. A long decay time observed in the later phase can be interpreted as a result of a slow deoxidization rate of chromium oxide, which may dominate the cleaning process in this phase. Optimization of plasma density for the cleaning is discussed comparing the experimental results on density dependence of water vapor pressure with a result based on a zero dimensional calculation for particle balance. One of the essential points for effective cleaning is the raising of the electron density of the plasma high enough that the dissociation loss rate of H2O is as large as the sticking loss rate. A density as high as 10 to the 11th power/cu cm is required for a clean surface condition where sticking probability is presumed to be around 0.5.

  19. Sulfur cement production using by products of the perchloroethylene coal cleaning process and the FC4-1 cleaned soil

    SciTech Connect

    Bassam Masri, K.L.; Fullerton, S.L.

    1995-12-31

    An introductory set of experiments to show the feasibility of making sulfur cement were carried out at the University of Akron according to Parrett and Currett`s patent which requires the use of sulfur, a filler, a plasticizer, and a vulcanization accelerator. Small blocks of cement were made using byproducts of the perchloroethylene coal cleaning process. Extracted elemental and organic sulfur, ash and mineral matters from the float sink portion of the PCE process, and FC4-1 cleaned soil were used as substitutes for sulfur and filler needed for the production of sulfur cement. Leaching tests in different solutions and under different conditions were conducted on the sulfur blocks. Other tests such as strength, durability, resistance to high or low temperatures will be conducted in the future. Sulfur cement can be used as a sealing agent at a joint, roofing purposes, forming ornamental figures, and coating of exposed surfaces of iron or steel. When mixed with an aggregate, sulfur concrete is formed. This concrete can be used for structural members, curbings, guthers, slabs, and can be precast or cast at the job site. An advantage of sulfur cement over Portland cement is that it reaches its design strength in two to three hours after processing and it can be remelted and recast.

  20. Fine coal cleaning via the micro-mag process

    DOEpatents

    Klima, Mark S.; Maronde, Carl P.; Killmeyer, Richard P.

    1991-01-01

    A method of cleaning particulate coal which is fed with a dense medium slurry as an inlet feed to a cyclone separator. The coal particle size distribution is in the range of from about 37 microns to about 600 microns. The dense medium comprises water and ferromagnetic particles that have a relative density in the range of from about 4.0 to about 7.0. The ferromagnetic particles of the dense medium have particle sizes of less than about 15 microns and at least a majority of the particle sizes are less than about 5 microns. In the cyclone, the particulate coal and dense-medium slurry is separated into a low gravity product stream and a high gravity produce stream wherein the differential in relative density between the two streams is not greater than about 0.2. The low gravity and high gravity streams are treated to recover the ferromagnetic particles therefrom.

  1. Optimizing EUV mask blank cleaning processes using the Lasertec M7360

    NASA Astrophysics Data System (ADS)

    Shimomura, Takeya; Kadaksham, Arun John; House, Matt; Ma, Andy; Goodwin, Frank

    2012-03-01

    EUV lithography is considered the most promising lithography solution for the 16 nm node and beyond. As EUV light is strongly absorbed by all known materials, reflective optics are used instead of conventional transmittance optics applied to ArF and KrF lithography. The EUV mask must also need be reflective. It typically consists of a Ta-based absorber layer, Ru capping layer, Si/Mo multilayer on a low thermal expansion material (LTEM) substrate with a backside Cr-based metal coating. Because of the strong absorbance of the EUV light, a pellicle is not practical. Therefore, EUV masks must be cleaned more frequently to maintain the necessary cleanliness. This poses numerous unique challenges in cleaning processes. For example, the EUV mask integrity, including critical dimension (CD), EUV reflectivity, and absorber thickness must be kept intact during multiple cleanings throughout the mask's lifetime. Requirements of defect size for the cleaning, furthermore, are becoming tighter as semiconductor circuit design rules get smaller. According to the International Technology Roadmap For Semiconductors (ITRS), the smallest defect size that must be removed is 23 nm for the 18 nm NAND Flash node in 2013. In addition to defects on the frontside, defects on a backside also need to be minimized since they might lead overlay error due to local distortions of EUV masks on an electrostatic chuck. This paper focuses on evaluations of cleaning performances using the Lasertec M1350 and M7360 blank inspection system, which has a 71 nm and 43 nm sensitivity. The 43nm is the current best sensitivity while keeping a >90% defect capture rate. First, the cleaning performance using the standard process has been investigated. We found a mitigation of adders was a key challenge for the EUV mask cleaning. The primary source of the adders was also identified as pits. Secondly, the megasonic cleaning process has been optimized to mitigate the adders. We could successfully reduce the adders by

  2. Characterization of an oxygen plasma process for cleaning packaged semiconductor devices. Final report

    SciTech Connect

    Adams, B.E.

    1996-11-01

    The purpose of this research was to experimentally determine the operating {open_quotes}window{close_quotes} for an oxygen plasma cleaning process to be used on microelectronics components just prior to wire bonding. The process was being developed to replace one that used vapor degreasing with trichlorotrifluoroethane, an ozone-depleting substance. A Box-Behnken experimental design was used to generate data from which the oxygen plasma cleaning process could be characterized. Auger electron spectrophotometry was used to measure the contamination thickness on the dice after cleaning. An empirical equation correlating the contamination thickness on the die surface with the operating parameters of the plasma system was developed from the collected Auger data, and optimum settings for cleaning semiconductor devices were determined. Devices were also tested for undesirable changes in electrical parameters resulting from cleaning in the plasma system. An increase in leakage current occurred for bipolar transistors and diodes after exposure to the oxygen plasma. Although an increase in leakage current occurred, each device`s parameter remained well below the acceptable specification limit. Based upon the experimental results, the optimum settings for the plasma cleaning process were determined to be 200 watts of power applied for five minutes in an enclosure maintained at 0.7 torr. At these settings, all measurable contamination was removed without compromising the reliability of the devices.

  3. Fast formation of superhydrophobic octadecylphosphonic acid (ODPA) coating for self-cleaning and oil/water separation.

    PubMed

    Dai, Chunai; Liu, Na; Cao, Yingze; Chen, Yuning; Lu, Fei; Feng, Lin

    2014-10-28

    A simple and fast method to prepare robust superhydrophobic octadecylphosphonic acid (ODPA) coating on oxidized copper mesh for self-cleaning and oil/water separation is reported here. The substrate of the copper mesh was first oxidized by simple immersion in an aqueous solution of 1.0 M NaOH and 0.05 M K2S2O8 at room temperature for 30 min, which was then covered with micro- and nanoscale Cu(OH)2 on the surface. Subsequently, the oxidized copper mesh was immersed in 2 × 10(-4) M octadecylphosphonic acid/tetrahydrofuran (ODPA/THF) solution, an ODPA coating formed on the oxidised copper mesh. The ODPA coating formation process takes place rapidly, almost in 1 second, which makes the as-prepared mesh exhibit superhydrophobicity with the water contact angle of approximately 158.9° and superoleophilicity with the oil contact angle of 0°. Moreover, the as-prepared mesh has self-cleaning effect and can be repeatedly used to efficiently separate a series of oil/water mixtures like gasoline/water and diesel/water. Interestingly, straightforward oxidation of a copper substrate produces a "water-removing" type oil/water separation mesh with underwater superoleophobicity, whereas ODPA coating on the oxidized copper mesh produces an "oil-removing" type oil/water separation mesh with superhydrophobicity and superoleophilicity. This interesting conversion results from a small amount of ODPA and takes place very rapidly. PMID:25177922

  4. Carboxylic acid sorption regeneration process

    DOEpatents

    King, C. Judson; Poole, Loree J.

    1995-01-01

    Carboxylic acids are sorbed from aqueous feedstocks into an organic liquid phase or onto a solid adsorbent. The acids are freed from the sorbent phase by treating it with aqueous alkylamine thus forming an alkylammonium carboxylate which is dewatered and decomposed to the desired carboxylic acid and the alkylamine.

  5. Carboxylic acid sorption regeneration process

    DOEpatents

    King, C.J.; Poole, L.J.

    1995-05-02

    Carboxylic acids are sorbed from aqueous feedstocks into an organic liquid phase or onto a solid adsorbent. The acids are freed from the sorbent phase by treating it with aqueous alkylamine thus forming an alkylammonium carboxylate which is dewatered and decomposed to the desired carboxylic acid and the alkylamine. 10 figs.

  6. ECR plasma cleaning: an in-situ processing technique for RF cavities

    SciTech Connect

    Wu, G.; Moeller, W-D.; Antoine, C.; Jiang, H.; Pechenezhskiy, I.; Cooley, L.; Khabiboulline, T.; Terechkine, Y.; Edwards, H.; Koeth, T.; Romanenko, A.; /Cornell U., Phys. Dept. /Jefferson Lab

    2008-01-01

    A condition for Electron Cyclotron Resonance (ECR) can be established inside a fully assembled RF cavity without the need for removing high-power couplers. As such, plasma generated by this process can be used as a final cleaning step, or as an alternative cleaning step in place of other techniques. Tests showed filtered dry air plasma can successfully remove sulfur particles on niobium surface while the surface oxygen content remains intact.

  7. The study and practice of clean coal pressure filter and dewatering process

    SciTech Connect

    Xie, G.; Wu, L.; Ou, Z.

    1999-07-01

    This paper introduces the current status of dewatering of the flotation clean coal and the problems in China. The industrial application of the dewatering process and the newly developed clean coal pressure filter is represented. And the results indicated that this filter press possesses such advantages as fast speed in filter lower moisture in filter cake, convenience in operation, obvious saving on energy, etc. It will have a broad applications.

  8. The cleaning and disinfecting of hemodialysis equipment using electrolyzed strong acid aqueous solution.

    PubMed

    Tanaka, N; Fujisawa, T; Daimon, T; Fujiwara, K; Yamamoto, M; Abe, T

    1999-04-01

    In general, sodium hypochlorite, formalin, and Dialox (Teijin Gambro Medical, Ltd., Tokyo, Japan [main ingredients: H2O2, CH3CHOOOH, CH3COOH, H2O]) are used to clean and disinfect hemodialysis pipelines. In this study, the suitability of electrolyzed strong acid aqueous solution (ESAAS), which has attracted considerable interest in Japan because of its strong disinfecting properties, was examined. The crossover method was used to investigate the effectiveness of ESAAS in disinfecting the dialysis pipelines in comparison to that of sodium hypochlorite (200 ppm) used alternately with 1% acetic acid. The number of bacteria and the concentration of endotoxin (Et) were measured over an approximately 3 year period, starting in September 1994. Until then, 200 ppm sodium hypochlorite had been used alternately with 1% acetic acid, and the contamination of the pipeline had been marked. However, after switching to the ESAAS disinfection method, the dialysis pipelines very rapidly became cleaner. Therefore, the decision to develop an automated ESAAS cleaning system for long-term use was made. During the development period, the original disinfectants (200 ppm sodium hypochlorite used alternately with 1% acetic acid) were used as a stopgap. After confirmation of its performance and safety, the automated ESAAS cleaning system was introduced. To find out whether the decrease in bacteria secondarily caused a decrease in the Et concentration or whether the ESAAS directly inactivated the Et, an in vitro experiment was carried out. Highly concentrated Et, which had been left in the reverse osmosis (RO) drainage pipeline, was used as a sample to investigate the effects of ESAAS on Et at various concentrations and temperatures and on the recovery test. The results showed that ESAAS directly inactivated Et. This paper reports the results of the crossover test. The results of parallel tests carried out over an approximately 4 year period have already been reported. No significant problems

  9. Development of the Ultra-Clean Dry Cleanup Process for Coal-Based Syngases

    SciTech Connect

    Newby, R.A.; Slimane, R.B.; Lau, F.S.; Jain, S.C.

    2002-09-20

    The Siemens Westinghouse Power Corporation (SWPC) has proposed a novel scheme for polishing sulfur species, halides, and particulate from syngas to meet stringent cleaning requirements, the ''Ultra-Clean syngas polishing process.'' The overall development objective for this syngas polishing process is to economically achieve the most stringent cleanup requirements for sulfur species, halide species and particulate expected for chemical and fuel synthesis applications (total sulfur species < 60 ppbv, halides < 10 ppbv, and particulate < 0.1 ppmw). A Base Program was conducted to produce ground-work, laboratory test data and process evaluations for a conceptual feasibility assessment of this novel syngas cleaning process. Laboratory testing focused on the identification of suitable sulfur and halide sorbents and operating temperatures for the process. This small-scale laboratory testing was also performed to provide evidence of the capability of the process to reach its stringent syngas cleaning goals. Process evaluations were performed in the Base Program to identify process alternatives, to devise process flow schemes, and to estimate process material & energy balances, process performance, and process costs. While the work has focused on sulfur, halide, and particulate control, considerations of ammonia, and mercury control have also been included.

  10. Influence of microbubble in physical cleaning of MF membrane process for wastewater reuse.

    PubMed

    Lee, Eui-Jong; Kim, Young-Hoon; Kim, Hyung-Soo; Jang, Am

    2015-06-01

    Currently, there is a growing emphasis on wastewater reclamation and reuse all over the world due to restricted water resources. Among a variety of wastewater reuse technologies, the use of microfiltration membranes (MF) is one of the popular processes because it has the ability to successfully eliminate particulates and colloidal matters. However, successful fouling control is not easy because effluents from the activated sludge process still contain small particulates and colloidal matters such as extracellular polymeric substance (EPS) and soluble microbial products (SMP). On the other hand, microbubbles have advantageous properties compared to common bubbles, but there hasn't been reporting of the use of microbubbles in physical cleaning instead of aeration. Encouraging results were obtained herein through the application of microbubbles for physical cleaning. In evaluation of the cleaning efficiency, the efficiency of microbubbles was observed to be twice as high as that of aeration, except during the course of the initial 30 min. Total organic carbon (TOC) concentration of the membrane tank after treatment with microbubbles was more than twice as high as that after aeration for physical cleaning. The membrane cleaned with microbubbles also had the smoothest surface, with a roughness of 42.5 nm. In addition, microbubbles were found to effectively remove EPS and make the structure of the gel layer loose. In particular, the microbubbles had the ability to remove proteins through the effect of pyrolytic decomposition. Therefore, in FT-IR spectra of the membrane surfaces taken before and after physical cleaning, while each treatment showed similar peak positions, the peak values of the membrane treated with microbubbles were the lowest. Through various analyses, it was confirmed that microbubbles can remove foulants on the gel layer in spite of their very low shear force. This means that microbubble cleaning has full potential for use as a physical cleaning

  11. MSO spent salt clean-up recovery process

    SciTech Connect

    Adamson, M G; Brummond, W A; Hipple, D L; Hsu, P C; Summers, L J; Von Holtz, E H; Wang, F T

    1997-02-01

    An effective process has been developed to separate metals, mineral residues, and radionuclides from spent salt, a secondary waste generated by Molten Salt Oxidation (MSO). This process includes salt dissolution, pH adjustment, chemical reduction and/or sulfiding, filtration, ion exchange, and drying. The process uses dithionite to reduce soluble chromate and/or sulfiding agent to suppress solubilities of metal compounds in water. This process is capable of reducing the secondary waste to less than 5% of its original weight. It is a low temperature, aqueous process and has been demonstrated in the laboratory [1].

  12. Study of Sn removal processes for in-situ collector cleaning

    NASA Astrophysics Data System (ADS)

    Elg, Daniel T.; Panici, Gianluca A.; Srivastava, Shailendra N.; Ruzic, D. N.

    2016-03-01

    An in-situ hydrogen plasma cleaning technique to clean Sn off of EUV collector optics is studied in detail. The cleaning process uses hydrogen radicals (formed in the hydrogen plasma) to interact with Sn-coated surfaces, forming SnH4 and being pumped away. This technique has been used to clean a 300mm-diameter stainless steel dummy collector optic, and EUV reflectivity of multilayer mirror samples was restored after cleaning Sn from them, validating the potential of this technology. This method has the potential to significantly reduce downtime and increase source availability. However, net Sn removal is limited by decomposition of the SnH4 molecule upon impact with the collector and the resulting redeposition of Sn. This is true in all cleaning systems that make use of hydrogen radicals. Thus, to guide the design of effective cleaning systems, the transport of Sn in the chamber, and the fundamental processes affecting it, must be understood. Accordingly, an investigation into these processes Sn removal is being performed. These processes include the advection of gas through the chamber, the creation of hydrogen radicals, the etching of Sn by radicals, and the surface decomposition of SnH4. In this paper, experiments to determine the radical density are presented, along with a theoretical plasma chemistry model that explains the processes behind radical creation and validates the radical density measurements. Additionally, experiments are shown that provide an insight into the etching of Sn by hydrogen radicals, yielding calculations of etching probability as well as showing that Sn etching is very sensitive to oxygen contamination and surface morphology.

  13. The mechanical stability of allografts after a cleaning process: comparison of two preparation modes.

    PubMed

    Putzer, David; Huber, Debora Coraca; Wurm, Alexander; Schmoelz, Werner; Nogler, Michael

    2014-08-01

    In revision hip arthroplasty, bone loss can be compensated by impacting allograft material. Cleaning processes reduce the risk of bacterial and viral contamination. Cleaned allograft material was compared to native untreated allografts by using a uniaxial compression test. 30 measurements were performed for each group before and after compaction. Grain size distribution and weight loss were determined. A reduction in the amount of large bone fragments and a higher compaction rate were observed in the cleaned bone grafts. The cleaned bone chips presented with a better mechanical resistance to a compression force and a reduced flowability. The benefit of a cleaner and a mechanical stable graft material comes with the drawback that higher initial amounts of graft material are needed. PMID:24793889

  14. Effect of Dissolved Oxygen on Cu Corrosion in Single Wafer Cleaning Process

    NASA Astrophysics Data System (ADS)

    Imai, Masayoshi; Yamashita, Yukinari; Futatsuki, Takashi; Shiohara, Morio; Kondo, Seiichi; Saito, Shuichi

    2009-04-01

    We investigated Cu corrosion at the via bottom of multi-layered Cu interconnects that occurred after post-etching wet cleaning and caused via open failures. We found that oxygen was dissolved into de-ionized water (DIW) on the wafer edge from the air atmosphere during the rinse step after chemical cleaning and that Cu was oxidized due to the high oxidation-reduction potential (ORP) of the rinse DIW. To prevent Cu interconnects from being corroded, control of the dissolved oxygen and the ORP of the rinse DIW by decreasing the oxygen concentration of the atmosphere in the cleaning machine as well as by using H2 water is required. This will become indispensable in the cleaning process of the next generation Cu interconnects.

  15. REINVESTIGATING THE PROCESS IMPACTS FROM OXALIC ACIDHIGH LEVEL WASTE TANK CLEANING

    SciTech Connect

    Ketusky, E

    2008-01-22

    The impacts and acceptability of using oxalic acid to clean the Savannah River Site, High Level Waste Tanks 1-8, were re-investigated using a two-phased approach. For the first phase, using a representative Tank 1-8 sludge, the chemical equilibrium based software, OLI ESP{copyright} and Savannah River Site laboratory test results were used to develop a chemically speciated material balance and a general oxalate mass balance. Using 8 wt% oxalic acid with a 100% molar excess, for every 1 kg of sludge solid that was dissolved, about 3.4 kg of resultant solids would form for eventual vitrification, while about 0.6 kg of soluble oxalate would precipitate in the evaporator system, and form a salt heel. Using available analyses, a list of potential safety and process impacts were developed, screened, and evaluated for acceptability. The results showed that the use of oxalic acid had two distinct types of impacts, those which were safety based and required potential upgrades or additional studies. Assuming such were performed and adequate, no further actions were required. The second type of impacts were also acceptable, but were long-term, and as such, would need to be managed. These impacts were directly caused by the solubility characteristics of oxalate in a concentrated sodium solution and, occurred after pH restoration. Since oxalate destruction methods are commonly available, their use should be considered. Using an oxalate destruction method could enable the benefits of oxalic to applied, while eliminating the long-term impacts that must be managed, and hence should be considered.

  16. Biofilms of Enterococcus faecalis and Enterococcus faecium isolated from the processing of ricotta and the control of these pathogens through cleaning and sanitization procedures.

    PubMed

    da Silva Fernandes, Meg; Kabuki, Dirce Yorika; Kuaye, Arnaldo Yoshiteru

    2015-05-01

    The biofilm formation of Enterococcus faecalis and Enterococcus faecium isolated from the processing of ricotta on stainless steel coupons was evaluated, and the effect of cleaning and sanitization procedures in the control of these biofilms was determined. The formation of biofilms was observed while varying the incubation temperature (7, 25 and 39°C) and time (0, 1, 2, 4, 6 and 8 days). At 7°C, the counts of E. faecalis and E. faecium were below 2 log10 CFU/cm(2). For the temperatures of 25 and 39°C, after 1 day, the counts of E. faecalis and E. faecium were 5.75 and 6.07 log10 CFU/cm(2), respectively, which is characteristic of biofilm formation. The tested sanitation procedures a) acid-anionic tensioactive cleaning, b) anionic tensioactive cleaning+sanitizer and c) acid-anionic tensioactive cleaning+sanitizer were effective in removing the biofilms, reducing the counts to levels below 0.4 log10 CFU/cm(2). The sanitizer biguanide was the least effective, and peracetic acid was the most effective. These studies revealed the ability of enterococci to form biofilms and the importance of the cleaning step and the type of sanitizer used in sanitation processes for the effective removal of biofilms. PMID:25702883

  17. Cleaning process for corrugated aluminum electrical transmission line enclosure

    DOEpatents

    Bowman, Gary K.

    1984-07-24

    A process for preparing the interior of a corrugated pipe or sheath comprises the steps of placing a predetermined amount of a tumbling abrasive material into the sheath, and then rotating the sheath.

  18. IMPACT OF NOX SELECTIVE CATALYTIC REDUCTION PROCESSES ON FLUE GAS CLEANING SYSTEMS

    EPA Science Inventory

    The report gives results of a study of the impact of the ammonia leaving a nitrogen oxide (NOx) selective catalytic reduction (SCR) process on downstream flue gas cleaning processes. (NOx emissions from electric utility boilers may be reduced 80-90% by the application of pollutio...

  19. Evaluation of seed cotton cleaning equipment performance at various processing rates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The processing rate per unit width of seed cotton cleaning equipment– cylinder cleaners and stick machines– recommended by manufacturers is 4.9-8.2 bales hr-1 m-1 (1.5-2.5 bales hr-1 ft-1). Survey data has indicated that many gins exceed this processing rate. Little research has been conducted wit...

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

    NASA Technical Reports Server (NTRS)

    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

  1. ToF-SIMS Investigation of the Effectiveness of Acid-Cleaning procedures for Genesis Solar Wind Collectors

    NASA Technical Reports Server (NTRS)

    Goreva, Y. S.; Humanyun, M.; Burnett, D. S.; Jurewicz, A. J.; Gonzalez, C. P.

    2014-01-01

    ToF-SIMS images of Genesis sample surfaces contain an incredible amount of important information, but they also show that the crash-derived surface contamination has many components, presenting a challenge to cleaning. Within the variability, we have shown that there are some samples which appear to be clean to begin with, e.g. 60471, and some are more contaminated. Samples 60493 and 60500 are a part of a focused study of the effectiveness of aqua regia and/or sulfuric acid cleaning of small flight Si implanted with Li-6 using ToF-SIMS.

  2. The TEES process cleans waste and produces energy

    NASA Astrophysics Data System (ADS)

    Elliott, D. C.; Silva, L. J.

    1995-02-01

    A gasification system is under development that can be used with most types of wet organic wastes. The system operates at 350 C and 205 atm using a liquid water phase as the processing medium. Since a pressurized system is used, the wet waste can be fed as a solution or slurry to the reactor without drying. Through the development of catalysts, a useful processing system has been produced. The system has utility both for direct conversion of high-moisture biomass to fuel gas or as a wastewater cleanup system for wet organic wastes including unconverted biomass from bioconversion processes. By the use of this system more than 99% conversions of organic waste to medium-Btu fuel gas can be achieved.

  3. Processes For Cleaning a Cathode Tube and Assemblies In A Hollow Cathode Assembly

    NASA Technical Reports Server (NTRS)

    Patterson, Michael J. (Inventor); Verhey, Timothy R. R. (Inventor); Soulas, George C. (Inventor)

    2001-01-01

    The present invention is a process for cleaning a cathode tube and other subassemblies in a hollow cathode assembly. In the disclosed process, hand covering elastomer gloves are used for handling all cathode assembly parts. The cathode tube and other subassemblies are cleaned with a lint-free cloth damped with acetone, then wiped with alcohol, immersed in ethyl alcohol or acetone, and ultrasonic agitation is applied, heating to 60 C. for ethyl alcohol or 56 C. for acetone. The cathode tube and other subassemblies are dried by blowing with nitrogen gas.

  4. Investigation of the impact of cleaning on the adhesive bond and the process implications

    SciTech Connect

    EMERSON,JOHN A.; GUESS,TOMMY R.; ADKINS,CAROL L. JONES; CURRO,JOHN G.; REEDY JR.,EARL DAVID; LOPEZ,EDWIN P.; LEMKE,PAUL A.

    2000-05-01

    While surface cleaning is the most common process step in DOE manufacturing operations, the link between a successful adhesive bond and the surface clean performed before adhesion is not well understood. An innovative approach that combines computer modeling expertise, fracture mechanics understanding, and cleaning experience to address how to achieve a good adhesive bond is discussed here to develop a capability that would result in reduced cleaning development time and testing, improved bonds, improved manufacturability, and even an understanding that leads to improved aging. A simulation modeling technique, polymer reference interaction site model applied near wall (Wall PRISM), provided the capability to include contaminants on the surface. Calculations determined an approximately 8% reduction in the work of adhesion for 1% by weight of ethanol contamination on the structure of a silicone adhesive near a surface. The demonstration of repeatable coatings and quantitative analysis of the surface for deposition of controlled amounts of contamination (hexadecane and mineral oil) was based on three deposition methods. The effect of the cleaning process used on interfacial toughness was determined. The measured interfacial toughness of samples with a Brulin cleaned sandblasted aluminum surface was found to be {approximately} 15% greater than that with a TCE cleaned aluminum surface. The sensitivity of measured fracture toughness to various test conditions determined that both interfacial toughness and interface corner toughness depended strongly on surface roughness. The work of adhesion value for silicone/silicone interface was determined by a contact mechanics technique known as the JKR method. Correlation with fracture data has allowed a better understanding between interfacial fracture parameters and surface energy.

  5. Controlling template erosion with advanced cleaning methods

    NASA Astrophysics Data System (ADS)

    Singh, SherJang; Yu, Zhaoning; Wähler, Tobias; Kurataka, Nobuo; Gauzner, Gene; Wang, Hongying; Yang, Henry; Hsu, Yautzong; Lee, Kim; Kuo, David; Dress, Peter

    2012-03-01

    We studied the erosion and feature stability of fused silica patterns under different template cleaning conditions. The conventional SPM cleaning is compared with an advanced non-acid process. Spectroscopic ellipsometry optical critical dimension (SE-OCD) measurements were used to characterize the changes in pattern profile with good sensitivity. This study confirmed the erosion of the silica patterns in the traditional acid-based SPM cleaning mixture (H2SO4+H2O2) at a rate of ~0.1nm per cleaning cycle. The advanced non-acid clean process however only showed CD shift of ~0.01nm per clean. Contamination removal & pattern integrity of sensitive 20nm features under MegaSonic assisted cleaning is also demonstrated.

  6. Potential effects of clean coal technologies on acid precipitation, greenhouse gases, and solid waste disposal

    SciTech Connect

    Blasing, T.J.; Miller, R.L.; McCold, L.N.

    1993-11-01

    The US Department of Energy`s (DOE`s) Clean Coal Technology Demonstration Program (CCTDP) was initially funded by Congress to demonstrate more efficient, economically feasible, and environmentally acceptable coal technologies. Although the environmental focus at first was on sulfur dioxide (SO{sub 2}) and nitrogen oxides (NO{sub x}) because their relationship to acid precipitation, the CCTDP may also lead to reductions in carbon dioxide (CO{sub 2}) emissions and in the volume of solid waste produced, compared with conventional technologies. The environmental effects of clean coal technologies (CCTs) depend upon which (if any) specific technologies eventually achieve high acceptance in the marketplace. In general, the repowering technologies and a small group of retrofit technologies show the most promise for reducing C0{sub 2} emissions and solid waste. These technologies also compare favorably with other CCTs in terms of SO{sub 2} and NO{sub x} reductions. The upper bound for CO{sup 2} reductions in the year 2010 is only enough to reduce global ``greenhouse`` warming potential by about 1%. However, CO{sub 2} emissions come from such variety of sources around the globe that no single technological innovation or national policy change could realistically be expected to reduce these emissions by more than a few percent. Particular CCTs can lead to either increases or decreases in the amount of solid waste produced. However, even if decreases are not achieved, much of the solid waste from clean coal technologies would be dry and therefore easier to dispose of than scrubber sludge.

  7. Clean burning process which converts pollutants into value added product

    SciTech Connect

    Zhu Xuefang

    1999-07-01

    By adding a multiple composite admixture in coal-fired boilers, the new technology turns ash and the sulfur in coal into cement clinker materials, deepens and stabilizes combustion process, decreases mechanical and chemical instabilities during combustion, and eliminates the production of NO{sub x}. While generating heat and power, the technology produces cement clinkers, and gets rid of the soot type of air pollution caused by cement kilns, thus effects a radical cure for the two pollution sources in coal-fired power plants and cement kilns. The new technology makes use of coal ashes as renewable resources, saves energy resources and the land needed to discard the ashes. Therefore, it benefits for ecological balance and economics.

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

    SciTech Connect

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

    1997-05-01

    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{sup 22} and 10{sup 23} photons per meter for a PSD measurement. Desorption yields for H{sub 2}, CO, CO{sub 2}, CH{sub 4}, and H{sub 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.

  9. NATO CCMS PILOT STUDY ON CLEAN PRODUCTS AND PROCESSES -(PHASE I) - 2002 ANNUAL REPORT

    EPA Science Inventory

    The annual report summarizes the activities of the NATO CCMS Pilot Study on clean products and processes for 2002, including the proceedings of the 2002 annual meeting held in Vilnius, Lithuania. The report presents a wealth of information on cleaner production activities in ove...

  10. NATO/CCMS PILOT STUDY - CLEAN PRODUCTS AND PROCESSES (PHASE I) 2000 ANNUAL REPORT, NUMBER 242

    EPA Science Inventory

    This annual report presents the proceedings of the Third Annual NATO/CCMS pilot study meeting in Copenhagen, Denmark. Guest speakers focused on efforts in the area of research of clean products and processes, life cycle analysis, computer tools and pollution prevention.

  11. NATO/CCMS PILOT STUDY CLEAN PRODUCTS AND PROCESSES (PHASE II) 2003 ANNUAL REPORT

    EPA Science Inventory

    The 6th annual meeting of the NATO CCMS Pilot Study, Clean Products and Processes, was held in Cetraro, Italy, from May 11 to 15, 2003. This was also the first meeting of its Phase II study. 24 country representatives attended this meeting. This meeting was very ably run by th...

  12. DEMONSTRATION OF A LIQUID CARBON DIOXIDE PROCESS FOR CLEANING METAL PARTS

    EPA Science Inventory

    The report gives results of a demonstration of liquid carbon dioxide (LCO2) as an alternative to chlorinated solvents for cleaning metal parts. It describes the LCO2 process, the parts tested, the contaminants removed, and results from preliminary laboratory testing and on-site d...

  13. Acidic deposition and soil processes

    SciTech Connect

    Newton, R.M.; April, R.H.

    1985-08-01

    The results of the Integrated Lake-Watershed Acidification Study (ILWAS) show that the sensitivity of a watershed to surface water acidification is determined by the flow paths of water through the terrestrial system. If the water infiltrates through the soils into the groundwater system, acid neutralization occurs through weathering reactions involving minerals in the soils and till. Runoff and shallow interflow result in acid surface waters. Flow paths are determined in the ILWAS watersheds by the thickness of the glacial till. Complete neutralization can occur even in areas underlain by sensitive bedrock if the flow path through the mineral horizons is long enough. This appears to hold even in areas outside of the Adirondacks. 11 references, 5 figures.

  14. Selection of a Non-ODC Solvent for Rubber Processing Equipment Cleaning

    NASA Technical Reports Server (NTRS)

    Morgan, R. E.; Thornton, T. N.; Semmel, L.; Selvidge, S. A.

    2003-01-01

    NASA/MSFC has recently acquired new equipment for the manufacture and processing of rubber and rubber containing items that are used in the Redesigned Solid Rocket Motor (RSRM) system. Work with a previous generation of rubber equipment at MSFC in the 1970's had involved the use of Oxygen Deficient Center (ODC's) such as 1,1,1-Trichloroethane or VOC's such as Toluene as the solvents of choice in cleaning the equipment. Neither of these options is practical today. This paper addresses the selection and screening of candidate cleaning solvents that are not only effective, but also meet the new environmental standards.

  15. Selection of a Non-ODC Solvent for Rubber Processing Equipment Cleaning

    NASA Technical Reports Server (NTRS)

    Morgan, R. E.; Thornton, T. N.; Semmel, L.; Selvidge, S. A.; Cash, Steve (Technical Monitor)

    2002-01-01

    NASA/MSFC has recently acquired new equipment for the manufacture and processing of rubber and rubber containing items that are used in the RSRM (Reusable Solid Rocket Motor) system. Work with a previous generation of rubber equipment at MSFC (Marshall Space Flight Center) in the 1970's had involved the use of ODC's such as 1,1,1-Trichloroethane or VOC's such as Toluene as the solvents of choice in cleaning the equipment. Neither of these options is practical today. This paper addresses the selection and screening of candidate cleaning solvents that are not only effective, but also meet the new environmental standards.

  16. ACTUAL-WASTE TESTS OF ENHANCED CHEMICAL CLEANING FOR RETRIEVAL OF SRS HLW SLUDGE TANK HEELS AND DECOMPOSITION OF OXALIC ACID

    SciTech Connect

    Martino, C.; King, W.; Ketusky, E.

    2012-01-12

    Savannah River National Laboratory conducted a series of tests on the Enhanced Chemical Cleaning (ECC) process using actual Savannah River Site waste material from Tanks 5F and 12H. Testing involved sludge dissolution with 2 wt% oxalic acid, the decomposition of the oxalates by ozonolysis (with and without the aid of ultraviolet light), the evaporation of water from the product, and tracking the concentrations of key components throughout the process. During ECC actual waste testing, the process was successful in decomposing oxalate to below the target levels without causing substantial physical or chemical changes in the product sludge.

  17. Process for producing and recovering elemental sulfur from acid gas

    SciTech Connect

    Reed, R. L.

    1985-03-26

    A system and process produce high actual levels of sulfur recovery from acid gas. The system includes two conventional Claus reactors and two cold bed adsorption (CBA) reactors. Four condensers are provided, one disposed before each of the catalytic reactors, and one disposed after the CBA reactor. The system includes a gas clean-up treatment zone for hydrogenation, drying and oxidation of gas to provide stoichiometric ratio of H/sub 2/S and SO/sub 2/. The gas is passed through the clean-up treatment zone prior to being fed to the first of the CBA reactors. The system is designed to operate either in a recovery mode or in a regeneration mode. In the recovery mode, the reactors are in series and the CBA reactors are operated below dew point of sulfur. In regeneration mode, effluent from the clean-up treatment zone is heated in a heat exchanger using effluent from the first catalytic reactor as the heat source. The resulting regeneration gas is fed to one of the two CBA reactors to vaporize sulfur and regenerate the catalyst. The vaporized sulfur is recovered in the condenser. The effluent from the condenser is passed to the other CBA reactor which is operated in the recovery mode during regeneration.

  18. EXPLORING ENGINEERING CONTROL THROUGH PROCESS MANIPULATION OF RADIOACTIVE LIQUID WASTE TANK CHEMICAL CLEANING

    SciTech Connect

    Brown, A.

    2014-04-27

    One method of remediating legacy liquid radioactive waste produced during the cold war, is aggressive in-tank chemical cleaning. Chemical cleaning has successfully reduced the curie content of residual waste heels in large underground storage tanks; however this process generates significant chemical hazards. Mercury is often the bounding hazard due to its extensive use in the separations process that produced the waste. This paper explores how variations in controllable process factors, tank level and temperature, may be manipulated to reduce the hazard potential related to mercury vapor generation. When compared using a multivariate regression analysis, findings indicated that there was a significant relationship between both tank level (p value of 1.65x10{sup -23}) and temperature (p value of 6.39x10{sup -6}) to the mercury vapor concentration in the tank ventilation system. Tank temperature showed the most promise as a controllable parameter for future tank cleaning endeavors. Despite statistically significant relationships, there may not be confidence in the ability to control accident scenarios to below mercury’s IDLH or PAC-III levels for future cleaning initiatives.

  19. Effect of Process Parameters on Particle Removal Efficiency in Poly(vinyl alcohol) Brush Scrubber Cleaning

    NASA Astrophysics Data System (ADS)

    An, Joonho; Lee, Hyunseop; Kim, Hyoungjae; Jeong, Haedo

    2012-02-01

    Wafer cleaning is one of the most critical processes in the semiconductor device manufacturing. Poly(vinyl alcohol) (PVA) brush scrubber cleaning is much attractive when compared with traditional wet-batch cleaning which causes the cross-contamination among the wafers in a bath and environmental issues with huge amount of chemical and deionized water (DIW) usages. The mechanical forces generated from PVA brush contact can remove the particles on a wafer surface under low concentration of chemical solution without cross-contamination. In this research, we monitored the change of the dynamic forces including normal and friction force generated by PVA brush contacts during cleaning process, and also investigated the effects of scrubbing conditions of PVA brush overlap and velocity, and the surface tension (low- or high-hydrophilic) of the wafer on the particle removal efficiency. The results show that the driving mechanism to remove the particle on a wafer surface can be changed by the PVA brush overlap and velocity condition such as the hydrodynamic drag force in the brush soft contact condition and friction force in the brush hard contact condition. The particle removal efficiency is higher under the low-hydrophilic surface having a low surface tension compared to high-hydrophilic surface.

  20. Evaluation, modelling and optimization of the cleaning process of contaminated plastic food refillables.

    PubMed

    Devlieghere, F; De Meulenaer, B; Sekitoleko, P; Estrella Garcia, A A; Huyghebaert, A

    1997-01-01

    In this study several types of bottle materials (glass, PET (polyethylene terephthalate), PC (polycarbonate), HDPE (high density polyethylene), PP (polypropylene) and PVC (polyvinyl chloride)) were evaluated in order to be used as food refillables, comparing the residual chemical contamination after classical caustic washing. Bottles were contaminated with model chemicals (chloroxylenol and d-limonene) and caustic washed with varied process parameters using a simulated laboratory-scale washing procedure. After washing, the chemical-contaminated bottles were filled with water and stored for 28 days at 37 degrees C. The concentrations of the model chemicals in the water after storage were taken as a measure of chemical contamination. The influence of the cleaning parameters (temperature, caustic and commercial additive concentration) was studied using response surface methodology. Washing temperature showed a significant influence on the removal of absorbed chemicals from surfaces compared with the effect of the caustic and especially the additive concentration. Optimization of caustic cleaning for the cleaning process in question led to better cleaning effectiveness, although none of the different washing conditions were able to remove all absorbed chemicals out of the polymeric resins. Commercially available plastic refillables (PET and PC) showed the best chemical rinsability. Glass bottles, however, had in every case the best rinsing characteristics. PMID:9373531

  1. 7 CFR 361.8 - Cleaning of imported seed and processing of certain Canadian-origin screenings.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 5 2013-01-01 2013-01-01 false Cleaning of imported seed and processing of certain... (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE IMPORTATION OF SEED AND SCREENINGS UNDER THE FEDERAL SEED ACT § 361.8 Cleaning of imported seed and processing of certain...

  2. Analysis of fusaric acid in maize using molecularly imprinted solid phase extraction (MISPE) clean-up and ion-pair LC with diode array UV detection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusaric acid is a phytotoxin and mycotoxin occasionally found in maize contaminated with Fusarium fungi. A selective sample clean-up procedure was developed to detect fusaric acid in maize using molecularly imprinted solid phase extraction (MISPE) clean-up coupled with ion-pair liquid chromatography...

  3. Optimizing a Cleaning Process for Multilayer-Dielectric- (MLD) Diffraction Grating

    SciTech Connect

    Ashe, B.; Giacofei, C.; Myhre, G.; Schmid, A.W.

    2008-01-30

    A critical component for the OMEGA EP short-pulse petawatt laser system is the grating compressor chamber. This large 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 grating compressor chamber, are four sets of tiled multilayer-dielectric-diffraction gratings that provide the capability for producing 2.6-kJ output IR energy per beam at 10 ps. 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 multilayer-dielectric 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. A number of these materials have significant optical absorbance; therefore, incomplete cleaning of these residues may result in the multilayer-dielectric gratings experiencing laser damage.

  4. The Cleaning of Aluminum Frame Assembly Units

    SciTech Connect

    Shen, T H

    2001-05-16

    The Brulin immersion and the precision cleaning experiments have shown that neither the Brulin solution nor the precision cleaning in AstroPak causes the smut formation on aluminum surfaces. The acid-bath cleaning in GTC is the primary source of the smut formation. The current GTC acid formulation etches the aluminum matrix quite aggressively, but does not appear to appreciably attack the Si particles. Therefore, this acid-bath cleaning will leave the cast-aluminum part surfaces with many protruded Si particles, which could potentially cause smut problems in the cleaning process down-stream. To ensure the removal of all loose Si particles from the cast-aluminum parts, it is necessary to physically hand-wipe and vigorously wash the acid-bath cleaned surfaces. Furthermore, the casting porosity in alloy A356 could be another source in causing high swipe readings in the FAU parts.

  5. Ohio Clean Fuels, Inc. , prototype commercial coal/oil co-processing plant project

    SciTech Connect

    Not Available

    1989-11-01

    This report discusses the economics of coal as a source of domestic petroleum products and clean power production. The following topics are discussed: Economic incentives for the use of coal; applications of coal/oil coprocessing including (a) integration with a refinery; (b) cost reduction technique for alternate new supplies of oil; (c) power production meeting acid rain controls and comparative economics of copro powered facilities vs conventional power plant technology; costs of non-conventional supplies of crude and costs of coprocessing compared with offshore conventional oil. 10 refs., 1 fig., 20 tabs.

  6. Temporal pulse cleaning by a self-diffraction process for ultrashort laser pulses

    NASA Astrophysics Data System (ADS)

    Xie, Na; Zhou, Kainan; Sun, Li; Wang, Xiaodong; Guo, Yi; Li, Qing; Su, Jingqin

    2014-11-01

    Applying the self-diffraction process to clean ultrashort laser pulses temporally is a recently developed effective way to temporal contrast enhancement. In this paper, we attempt to clean ultrashort laser pulses temporally by the self-diffraction process. Experiments were carried out to study the temporal contrast improvement in the front-end system of an ultraintense and ultrashort laser facility, i.e. the super intense laser for experiment on the extremes (SILEX-I). The results show that the maximum conversion efficiency of the first-order self-diffraction (SD1) pulse is 11%. The temporal contrast of the SD1 signal is improved by two orders of magnitude, i.e. to 103, for a 2.4-ns prepulse with initial contrast of ~10. For a 5.5 -ns prepulse with initial contrast of 2×103, the temporal contrast of the SD1 signal is improved by more than three orders of magnitude.

  7. Cleaning and sanitation of Salmonella-contaminated peanut butter processing equipment.

    PubMed

    Grasso, Elizabeth M; Grove, Stephen F; Halik, Lindsay A; Arritt, Fletcher; Keller, Susanne E

    2015-04-01

    Microbial contamination of peanut butter by Salmonella poses a significant health risk as Salmonella may remain viable throughout the product shelf life. Effective cleaning and sanitation of processing lines are essential for preventing cross-contamination. The objective of this study was to evaluate the efficacy of a cleaning and sanitation procedure involving hot oil and 60% isopropanol, ± quaternary ammonium compounds, to decontaminate pilot-scale processing equipment harboring Salmonella. Peanut butter inoculated with a cocktail of four Salmonella serovars (∼ 7 log CFU/g) was used to contaminate the equipment (∼ 75 L). The system was then emptied of peanut butter and treated with hot oil (90 °C) for 2 h followed by sanitizer for 1 h. Microbial analysis of food-contact surfaces (7 locations), peanut butter, and oil were conducted. Oil contained ∼ 3.2 log CFU/mL on both trypticase soy agar with yeast extract (TSAYE) and xylose lysine deoxycholate (XLD), indicating hot oil alone was not sufficient to inactivate Salmonella. Environmental sampling found 0.25-1.12 log CFU/cm(2) remaining on processing equipment. After the isopropanol sanitation (± quaternary ammonium compounds), no Salmonella was detected in environmental samples on XLD (<0.16 log CFU/cm(2)). These data suggest that a two-step hot oil clean and isopropanol sanitization treatment may eliminate pathogenic Salmonella from contaminated equipment. PMID:25475272

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

    PubMed

    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. PMID:26277669

  9. Extensive separations (CLEAN) processing strategy compared to TRUEX strategy and sludge wash ion exchange

    SciTech Connect

    Knutson, B.J.; Jansen, G.; Zimmerman, B.D.; Seeman, S.E.; Lauerhass, L.; Hoza, M.

    1994-08-01

    Numerous pretreatment flowsheets have been proposed for processing the radioactive wastes in Hanford`s 177 underground storage tanks. The CLEAN Option is examined along with two other flowsheet alternatives to quantify the trade-off of greater capital equipment and operating costs for aggressive separations with the reduced waste disposal costs and decreased environmental/health risks. The effect on the volume of HLW glass product and radiotoxicity of the LLW glass or grout product is predicted with current assumptions about waste characteristics and separations processes using a mass balance model. The prediction is made on three principal processing options: washing of tank wastes with removal of cesium and technetium from the supernatant, with washed solids routed directly to the glass (referred to as the Sludge Wash C processing strategy); the previous steps plus dissolution of the solids and removal of transuranic (TRU) elements, uranium, and strontium using solvent extraction processes (referred to as the Transuranic Extraction Option C (TRUEX-C) processing strategy); and an aggressive yet feasible processing strategy for separating the waste components to meet several main goals or objectives (referred to as the CLEAN Option processing strategy), such as the LLW is required to meet the US Nuclear Regulatory Commission Class A limits; concentrations of technetium, iodine, and uranium are reduced as low as reasonably achievable; and HLW will be contained within 1,000 borosilicate glass canisters that meet current Hanford Waste Vitrification Plant glass specifications.

  10. NATO/CCMS PILOT STUDY CLEAN PRODUCTS AND PROCESSES (PHASE 1) 1998 ANNUAL REPORT (EPA/600/R-98/065)

    EPA Science Inventory

    This annual report presents the proceedings of the first annual NATO/CCMS pilot study meeting in Cincinnati in March 1998. Guest speakers focused on efforts in the research arena of clean products, clean processes, life cycle analysis, ecolabeling, and pollution prevention tools.

  11. Motor fuel alkylation process utilizing low acid

    SciTech Connect

    Kocal, J.A.; Imai, T.

    1987-01-06

    A process is described for the alkylation of an isoparaffin with an olefin acting agent comprising contacting the isoparaffin with the olefin acting agent at alkylation conditions in the presence of a catalyst. The catalyst consists essentially of an anhydrous, nonalcoholic mixture of from about 5 to 15 wt. % methyl tert-butyl ether and from 85 to 95 wt. % hydrofluoric acid. The volumetric ratio of hydrofluoric acid to isoparaffin and olefin acting agent is less than 0.75.

  12. Application of non-invasive optical monitoring methodologies to follow and record painting cleaning processes

    NASA Astrophysics Data System (ADS)

    Fontana, R.; Dal Fovo, A.; Striova, J.; Pezzati, L.; Pampaloni, E.; Raffaelli, M.; Barucci, M.

    2015-11-01

    The cleaning of painted artworks, i.e. the critical operation whereby materials are selectively removed from a painted surface by partial thinning or complete elimination of varnish, is one of the most debated conservation operations, being an irreversible process, which may result in chromatic and morphological variations in the painted surface. Due to ageing, the upper layer is subject to darkening and yellowing because of blanching and fading from ultraviolet exposure, dust deposition, and overpainted layers due, for instance, to restoration interventions. This degradation can either alter the original appearance of painting polychromy or cause mechanical failure of the finishes. To address these adverse conditions, a process of examination and analysis is critical to the definition and interpretation of the varnish layer. When investigating the ageing process of old paintings, it is of great importance to obtain insight into the painting technique as practiced in the past, and the first step in gaining this knowledge is, to a large extent, based on the study of the varnish film. An effective control of the process and objective evaluation of its outcome requires therefore instrumental/analytical support. The present study illustrates the successful application of non-invasive optical techniques—such as colorimetry, multispectral reflectography, laser scanning micro-profilometry, and optical coherence tomography—to the monitoring of an Italian fourteenth-century painting cleaning process. Results presented here confirm that optical techniques play a pivotal role in artwork diagnostics, especially with regard to conservation operations, while also indicating their validity when applied to the monitoring of the cleaning process.

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

    PubMed

    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

  14. ELECTROCHEMICAL STUDIES ON THE CORROSION OF CARBON STEEL IN OXALIC ACID CLEANING SOLUTIONS

    SciTech Connect

    Wiersma, B; John Mickalonis, J

    2007-10-08

    The Savannah River Site (SRS) will disperse or dissolve precipitated metal oxides as part of radioactive waste tank closure operations. Previously SRS has utilized oxalic acid to accomplish this task. Since the waste tanks are constructed of carbon steel, a significant amount of corrosion may occur. Although the total amount of corrosion may be insignificant for a short contact time, a significant amount of hydrogen may be generated due to the corrosion reaction. Linear polarization resistance and anodic/cathodic polarization tests were performed to investigate the corrosion behavior during the process. The effect of process variables such as temperature, agitation, aeration, sample orientation, light as well as surface finish on the corrosion behavior were evaluated. The results of the tests provided insight into the corrosion mechanism for the iron-oxalic acid system.

  15. Thermal acidization and recovery process for recovering viscous petroleum

    DOEpatents

    Poston, Robert S.

    1984-01-01

    A thermal acidization and recovery process for increasing production of heavy viscous petroleum crude oil and synthetic fuels from subterranean hydrocarbon formations containing clay particles creating adverse permeability effects is described. The method comprises injecting a thermal vapor stream through a well bore penetrating such formations to clean the formation face of hydrocarbonaceous materials which restrict the flow of fluids into the petroleum-bearing formation. Vaporized hydrogen chloride is then injected simultaneously to react with calcium and magnesium salts in the formation surrounding the bore hole to form water soluble chloride salts. Vaporized hydrogen fluoride is then injected simultaneously with its thermal vapor to dissolve water-sensitive clay particles thus increasing permeability. Thereafter, the thermal vapors are injected until the formation is sufficiently heated to permit increased recovery rates of the petroleum.

  16. Effect of a new regeneration process by adsorption-coagulation and flocculation on the physicochemical properties and the detergent efficiency of regenerated cleaning solutions.

    PubMed

    Blel, Walid; Dif, Mehdi; Sire, Olivier

    2015-05-15

    Reprocessing soiled cleaning-in-place (CIP) solutions has large economic and environmental costs, and it would be cheaper and greener to recycle them. In food industries, recycling of CIP solutions requires a suitable green process engineered to take into account the extreme physicochemical conditions of cleaning while not altering the process efficiency. To this end, an innovative treatment process combining adsorption-coagulation with flocculation was tested on multiple recycling of acid and basic cleaning solutions. In-depth analysis of time-course evolutions was carried out in the physicochemical properties (concentration, surface tension, viscosity, COD, total nitrogen) of these solutions over the course of successive regenerations. Cleaning and disinfection efficiencies were assessed based on both microbiological analyses and organic matter detachment and solubilization from fouled stainless steel surfaces. Microbiological analyses using a resistant bacterial strain (Bacillus subtilis spores) highlighted that solutions regenerated up to 20 times maintained the same bactericidal efficiency as de novo NaOH solutions. The cleanability of stainless steel surfaces showed that regenerated solutions allow better surface wettability, which goes to explain the improved detachment and solubilization found on different types of organic and inorganic fouling. PMID:25770957

  17. Recycled fatty acid crude petroleum recovery process

    SciTech Connect

    Herter, G. L.; Herter, C.

    1984-11-06

    A method of recovering crude oil for subsequent processing. The method contemplates the step of exposing the source of crude oil such as a subterranean petroleum reservoir or a vessel or container of tar sands, kerogen or the like to aliphatic or carboxylic acid, preferably oleic acid, to produce a solvated crude oil mixture of reduced viscosity. This mixture is saponifyed by reacting it with a nucleophilic base, preferably a hydroxide of potassium or sodium, under pressure whereby to separate the solvated mixture into petroleum crude and an acid soap which migrates to an aqueous phase. The petroleum crude is separated from the aqueous soap through conventional techniques. Afterwards, a desaponification step contemplates recovery of the aliphatic or carboxylic acid for subsequent recycling in the previously mentioned exposing step. Reuse is facilitated by desaponifying aqueous soap within a high pressure containment vessel reacted with an acid suitable for donating a hydrated proton to the aqueous phase of the soap. This reconstituted acid is recycled for injection into the inputting step. Preferably carbonic acid is generated for the desaponifying step by injecting high pressure carbon dioxide within the containment vessel. By-products of the chemical reaction are separated and/or filtered as necessary to effectuate necessary purification sub-steps.

  18. Fouling of a spiral-wound reverse osmosis membrane processing swine wastewater: effect of cleaning procedure on fouling resistance.

    PubMed

    Camilleri-Rumbau, M S; Masse, L; Dubreuil, J; Mondor, M; Christensen, K V; Norddahl, B

    2016-01-01

    Swine manure is a valuable source of nitrogen, phosphorus and potassium. After solid-liquid separation, the resulting swine wastewater can be concentrated by reverse osmosis (RO) to produce a nitrogen-potassium rich fertilizer. However, swine wastewater has a high fouling potential and an efficient cleaning strategy is required. In this study, a semi-commercial farm scale RO spiral-wound membrane unit was fouled while processing larger volumes of swine wastewater during realistic cyclic operations over a 9-week period. Membrane cleaning was performed daily. Three different cleaning solutions, containing SDS, SDS+EDTA and NaOH were compared. About 99% of the fouling resistance could be removed by rinsing the membrane with water. Flux recoveries (FRs) above 98% were achieved for all the three cleaning solutions after cleaning. No significant differences in FR were found between the cleaning solutions. The NaOH solution thus is a good economical option for cleaning RO spiral-wound membranes fouled with swine wastewater. Soaking the membrane for 3 days in permeate water at the end of each week further improved the FR. Furthermore, a fouling resistance model for predicting the fouling rate, permeate flux decay and cleaning cycle periods based on processing time and swine wastewater conductivity was developed. PMID:26698296

  19. Instrumentation With Ultrasonic Scalers Facilitates Cleaning of the Sandblasted and Acid-Etched Titanium Implants.

    PubMed

    Park, Jun-Beom; Lee, Sung-Hoon; Kim, NamRyang; Park, Seojin; Jin, Seong-Ho; Choi, Bong-Kyu; Kim, Kack-Kyun; Ko, Youngkyung

    2015-08-01

    Mechanical instrumentation is widely used to debride dental implants, but this may alter the surface properties of titanium, which in turn may influence bacterial adhesion and make it more difficult to remove the biofilm. This in vitro study was performed (1) to assess the amount of biofilm formation on a sand-blasted and acid-etched titanium fixture treated with ultrasonic scalers with metal, plastic, and carbon tips and (2) to evaluate how this treatment of titanium surfaces affects implant cleaning by brushing with dentifrice. The titanium fixtures were treated with various ultrasonic scaler tips, and surface roughness parameters were measured by confocal microscopy. Biofilm was formed on the treated fixtures by using pooled saliva from 10 subjects, and the quantity of the adherent bacteria was compared with crystal violet assay. The fixture surfaces with biofilm were brushed for total of 30 seconds with a toothbrush with dentifrice. The bacteria remaining on the brushed fixture surfaces were quantified by scanning electron microscopy. Surface changes were evident, and the changes of the surfaces were more discernible when metal tips were used. A statistically significant decrease in roughness value (arithmetic mean height of the surface) was seen in the 2 metal-tip groups and the single plastic-tip group. After brushing with dentifrice, the treated surfaces in all the treatment groups showed significantly fewer bacteria compared with the untreated surfaces in the control group, and the parts of the surfaces left untreated in the test groups. Within the limits of this study, treatment of titanium fixture surfaces with ultrasonic metal, plastic, or carbon tips significantly enhanced the bacterial removal efficacy of brushing. Thorough instrumentation that smooths the whole exposed surface may facilitate maintenance of the implants. PMID:24552131

  20. Gas-Liquid Supersonic Cleaning and Cleaning Verification Spray System

    NASA Technical Reports Server (NTRS)

    Parrish, Lewis M.

    2009-01-01

    NASA Kennedy Space Center (KSC) recently entered into a nonexclusive license agreement with Applied Cryogenic Solutions (ACS), Inc. (Galveston, TX) to commercialize its Gas-Liquid Supersonic Cleaning and Cleaning Verification Spray System technology. This technology, developed by KSC, is a critical component of processes being developed and commercialized by ACS to replace current mechanical and chemical cleaning and descaling methods used by numerous industries. Pilot trials on heat exchanger tubing components have shown that the ACS technology provides for: Superior cleaning in a much shorter period of time. Lower energy and labor requirements for cleaning and de-scaling uper.ninih. Significant reductions in waste volumes by not using water, acidic or basic solutions, organic solvents, or nonvolatile solid abrasives as components in the cleaning process. Improved energy efficiency in post-cleaning heat exchanger operations. The ACS process consists of a spray head containing supersonic converging/diverging nozzles, a source of liquid gas; a novel, proprietary pumping system that permits pumping liquid nitrogen, liquid air, or supercritical carbon dioxide to pressures in the range of 20,000 to 60,000 psi; and various hoses, fittings, valves, and gauges. The size and number of nozzles can be varied so the system can be built in configurations ranging from small hand-held spray heads to large multinozzle cleaners. The system also can be used to verify if a part has been adequately cleaned.

  1. Process for the preparation of lactic acid and glyceric acid

    DOEpatents

    Jackson, James E [Haslett, MI; Miller, Dennis J [Okemos, MI; Marincean, Simona [Dewitt, MI

    2008-12-02

    Hexose and pentose monosaccharides are degraded to lactic acid and glyceric acid in an aqueous solution in the presence of an excess of a strongly anionic exchange resin, such as AMBERLITE IRN78 and AMBERLITE IRA400. The glyceric acid and lactic acid can be separated from the aqueous solution. Lactic acid and glyceric acid are staple articles of commerce.

  2. PROCESS FOR PRODUCING ALKYL ORTHOPHOSPHORIC ACID EXTRACTANTS

    DOEpatents

    Grinstead, R.R.

    1962-01-23

    A process is given for producing superior alkyl orthophosphoric acid extractants for use in solvent extraction methods to recover and purify various metals such as uranium and vanadium. The process comprises slurrying P/sub 2/O/ sub 5/ in a solvent diluent such as kerosene, benzene, isopropyl ether, and the like. An alipbatic alcohol having from nine to seventeen carbon atoms, and w- hcrein ihc OH group is situated inward of the terminal carbon atoms, is added to the slurry while the reaction temperature is mainiained below 60 deg C. The alcohol is added in the mole ratio of about 2 to l, alcohol to P/sub 2/O/sub 5/. A pyrophosphate reaotion product is formed in the slurry-alcohol mixture. Subsequently, the pyrophosphate reaction product is hydrolyzed with dilute mineral acid to produce the desired alkyl orthophosphoric aeid extractant. The extraetant may then be separated and utilized in metal-recovery, solvent- extraction processes. (AEC)

  3. Sulfur-free cleaning strategy for advanced mask manufacturing

    NASA Astrophysics Data System (ADS)

    Kindt, Louis; Watts, Andrew; Burnham, Jay; Aaskov, William

    2006-10-01

    Existing cleaning technology using sulfuric acid based chemistry has served the mask industry quite well over the years. However, the existence of residue on mask surfaces is becoming more and more of a problem at the high energy wavelengths used in lithography tool for wafer manufacturing. This is evident by the emergence of sub-pellicle defect growth and backside hazing issues. A large source of residual contamination on the surface of masks is from the mask manufacturing process, particularly the cleaning portion involving sulfuric acid. Cleaning strategies can be developed that eliminate the use of sulfuric acid in the cleaning process for advanced photomasks and alternative processes can be used for cleaning masks at various stages of the manufacturing process. Implementation of these new technologies into manufacturing will be discussed as will the resulting improvements, advantages, and disadvantages over pre-existing mask cleaning processes.

  4. IMPROVED PROCESSES TO REMOVE NAPHTHENIC ACIDS

    SciTech Connect

    Aihua Zhang; Qisheng Ma; William A. Goddard; Yongchun Tang

    2004-04-28

    In the first year of this project, we have established our experimental and theoretical methodologies for studies of the catalytic decarboxylation process. We have developed both glass and stainless steel micro batch type reactors for the fast screening of various catalysts with reaction substrates of model carboxylic acid compounds and crude oil samples. We also developed novel product analysis methods such as GC analyses for organic acids and gaseous products; and TAN measurements for crude oil. Our research revealed the effectiveness of several solid catalysts such as NA-Cat-1 and NA-Cat-2 for the catalytic decarboxylation of model compounds; and NA-Cat-5{approx}NA-Cat-9 for the acid removal from crude oil. Our theoretical calculations propose a three-step concerted oxidative decarboxylation mechanism for the NA-Cat-1 catalyst.

  5. Improved Processes to Remove Naphthenic Acids

    SciTech Connect

    Aihua Zhang; Qisheng Ma; Kangshi Wang; Yongchun Tang; William A. Goddard

    2005-12-09

    In the past three years, we followed the work plan as we suggested in the proposal and made every efforts to fulfill the project objectives. Based on our large amount of creative and productive work, including both of experimental and theoretic aspects, we received important technical breakthrough on naphthenic acid removal process and obtained deep insight on catalytic decarboxylation chemistry. In detail, we established an integrated methodology to serve for all of the experimental and theoretical work. Our experimental investigation results in discovery of four type effective catalysts to the reaction of decarboxylation of model carboxylic acid compounds. The adsorption experiment revealed the effectiveness of several solid materials to naphthenic acid adsorption and acidity reduction of crude oil, which can be either natural minerals or synthesized materials. The test with crude oil also received promising results, which can be potentially developed into a practical process for oil industry. The theoretical work predicted several possible catalytic decarboxylation mechanisms that would govern the decarboxylation pathways depending on the type of catalysts being used. The calculation for reaction activation energy was in good agreement with our experimental measurements.

  6. Fabrication of free standing anodic titanium oxide membranes with clean surface using recycling process.

    PubMed

    Meng, Xianhui; Lee, Tae-Young; Chen, Huiyu; Shin, Dong-Wook; Kwon, Kee-Won; Kwon, Sang Jik; Yoo, Ji-Beom

    2010-07-01

    Large area of self-organized, free standing anodic titanium oxide (ATO) nanotube membranes with clean surfaces were facilely prepared to desired lengths via electrochemical anodization of highly pure Ti sheets in an ethylene glycol electrolyte, with a small amount of NH4F and H2O at 50 V, followed by self-detachment of the ATO membrane from the Ti substrate using recycling processes. In the first anodization step, the nanowire oxide layer existed over the well-arranged ATO nanotube. After sufficiently rinsing with water, the whole ATO layer was removed from the Ti sheet by high pressure N2 gas, and a well-patterned dimple layer with a thickness of about 30 nm existed on the Ti substrate. By using these naturally formed nano-scale pits as templates, in the second and third anodization process, highly ordered, vertically aligned, and free standing ATO membranes with the anodic aluminum oxide (AAO)-like clean surface were obtained. The inter-pore distance and diameter was 154 +/- 2 nm and 91+/- 2 nm, the tube arrays lengths for 25 and 46 hours were 44 and 70 microm, respectively. The present study demonstrates a simple approach to producing high quality, length controllable, large area TiO2 membrane. PMID:21128409

  7. Ultrasonically treated liquid interfaces for progress in cleaning and separation processes.

    PubMed

    Radziuk, Darya; Möhwald, Helmuth

    2016-01-01

    Ultrasound and acoustic cavitation enable ergonomic and eco-friendly treatment of complex liquids with outstanding performance in cleaning, separation and recycling of resources. A key element of ultrasonic-based technology is the high speed of mixing by streams, flows and jets (or shock waves), which is accompanied by sonochemical reactions. Mass transfer across the phase boundary with a great variety of catalytic processes is substantially enhanced through acoustic emulsification. Encapsulation, separation and recovery of liquids are fast with high production yield if applied by ultrasound. Here we discuss the state of knowledge of these processes by ultrasound and acoustic cavitation from a perspective of a physico-chemical model in order to predict and control the outcome. We focus on the physical interpretation and quantification of ultrasonic parameters and properties of liquids to understand the chemistry of liquid/liquid interfaces in acoustic fields. The roles of thermodynamic enthalpy and entropy (incl. Laplace and osmotic pressure) in the context of sonochemical reactions (separation, catalysis, degradation, cross-linking, ion exchange and phase transfer) are outlined. The synergy of ultrasound and electric fields or continuous flow chemistry for cleaning and separation via emulsification is highlighted by specific strategies involving polymers and ultrasonic membranes. PMID:26435267

  8. A New Process for Acrylic Acid Synthesis by Fermentative Process

    NASA Astrophysics Data System (ADS)

    Lunelli, B. H.; Duarte, E. R.; de Toledo, E. C. Vasco; Wolf Maciel, M. R.; Maciel Filho, R.

    With the synthesis of chemical products through biotechnological processes, it is possible to discover and to explore innumerable routes that can be used to obtain products of high addes value. Each route may have particular advantages in obtaining a desired product, compared with others, especially in terms of yield, productivity, easiness to separate the product, economy, and environmental impact. The purpose of this work is the development of a deterministic model for the biochemical synthesis of acrylic acid in order to explore an alternative process. The model is built-up with the tubular reactor equations together with the kinetic representation based on the structured model. The proposed process makes possible to obtain acrylic acid continuously from the sugar cane fermentation.

  9. Clean coal technology and acid rain compliance: An examination of alternative incentive proposals

    SciTech Connect

    McDermott, K.A.; South, D.W.

    1991-12-31

    The Clean Air Act Amendments (CAAA) of 1990 rely primarily on the use of market incentives to stimulate least-cost compliance choices by electric utilities. Because of the potential risks associated with selecting Clean Coal Technologies (CCTs) and the public-good nature of technology commercialization, electric utilities may be reluctant to adopt CCTs as part of their compliance strategies. This paper examines the nature of the risks and perceived impediments to adopting CCTs as a compliance option. It also discusses the incentives that regulatory policy makers could adopt to mitigate these barriers to CCT adoption. (VC)

  10. Clean coal technology and acid rain compliance: An examination of alternative incentive proposals

    SciTech Connect

    McDermott, K.A. ); South, D.W. )

    1991-01-01

    The Clean Air Act Amendments (CAAA) of 1990 rely primarily on the use of market incentives to stimulate least-cost compliance choices by electric utilities. Because of the potential risks associated with selecting Clean Coal Technologies (CCTs) and the public-good nature of technology commercialization, electric utilities may be reluctant to adopt CCTs as part of their compliance strategies. This paper examines the nature of the risks and perceived impediments to adopting CCTs as a compliance option. It also discusses the incentives that regulatory policy makers could adopt to mitigate these barriers to CCT adoption. (VC)

  11. Solar production of industrial process steam at the Home Cleaning and Laundry Co. Final technical report

    SciTech Connect

    Not Available

    1984-06-01

    This report presents the results of the operation and performance evaluation period at the Home Laundry Solar Industrial Process Heat Project at Pasadena, California. The installation comprises 6496 ft/sup 2/ (603.5 m/sup 2/) of linear parabolic trough concentrating collectors supplying solar thermal energy for use in laundry and dry cleaning processes. The design phase began in September 1977, and an acceptance test was conducted during the week of April 12, 1982. The plant has been in operation since May 1982, with the 12-month Phase III (operational) period starting in October 1982. The objective of the operational evaluation experiment was to maximize energy delivery to the industrial participant while characterizing system performance. Data were acquired for monthly documentation of system performance, maintenance requirements, and operating costs.

  12. Separate olefin processing in sulfuric acid alkylation

    SciTech Connect

    Imhoff, S.A.; Graves, D.C.

    1995-09-01

    This paper will discuss the effects of alkylating propylene, butylenes and amylenes together and suggest alternative processing schemes which will minimize the negative synergies, improve octane and/or minimize acid consumption. The first option will show the impact of segregating the propylene and amylenes. In the second option, the benefit of alkylating the individual olefins at their optimal acid strengths will be presented. Additionally, each olefin`s optimal reaction conditions will be examined. Unfortunately, many refiners may not have the existing flexibility to take advantage of separate olefin processing. First, the majority of the propylene, butylenes and amylenes must be separate upon entry to the alkylation unit. If the olefins cannot be segregated upstream, separate olefin processing will not be as beneficial. If this is the case, then the benefits of separate olefin processing will have to be weighed versus the capital and energy costs required to separate them. In addition, small units may not have sufficient numbers of Contactors and settlers to achieve adequate segregation. Later in this paper, the modifications required in the alkylation unit for separate olefin processing will be discussed.

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

    NASA Astrophysics Data System (ADS)

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

    2010-10-01

    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 CuSO4 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.

  14. Investigation of the Timesaver process for de-burring and cleaning the plate for the Atlas Tilecalorimeter

    SciTech Connect

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

    1997-11-25

    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.

  15. Active biopolymers in green non-conventional media: a sustainable tool for developing clean chemical processes.

    PubMed

    Lozano, Pedro; Bernal, Juana M; Nieto, Susana; Gomez, Celia; Garcia-Verdugo, Eduardo; Luis, Santiago V

    2015-12-21

    The greenness of chemical processes turns around two main axes: the selectivity of catalytic transformations, and the separation of pure products. The transfer of the exquisite catalytic efficiency shown by enzymes in nature to chemical processes is an important challenge. By using appropriate reaction systems, the combination of biopolymers with supercritical carbon dioxide (scCO2) and ionic liquids (ILs) resulted in synergetic and outstanding platforms for developing (multi)catalytic green chemical processes, even under flow conditions. The stabilization of biocatalysts, together with the design of straightforward approaches for separation of pure products including the full recovery and reuse of enzymes/ILs systems, are essential elements for developing clean chemical processes. By understanding structure-function relationships of biopolymers in ILs, as well as for ILs themselves (e.g. sponge-like ionic liquids, SLILs; supported ionic liquids-like phases, SILLPs, etc.), several integral green chemical processes of (bio)catalytic transformation and pure product separation are pointed out (e.g. the biocatalytic production of biodiesel in SLILs, etc.). Other developments based on DNA/ILs systems, as pathfinder studies for further technological applications in the near future, are also considered. PMID:26497761

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

    SciTech Connect

    Suardini, P.J.

    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.

  17. Monte Carlo simulations of the clean and disordered contact process in three dimensions.

    PubMed

    Vojta, Thomas

    2012-11-01

    The absorbing-state transition in the three-dimensional contact process with and without quenched randomness is investigated by means of Monte Carlo simulations. In the clean case, a reweighting technique is combined with a careful extrapolation of the data to infinite time to determine with high accuracy the critical behavior in the three-dimensional directed percolation universality class. In the presence of quenched spatial disorder, our data demonstrate that the absorbing-state transition is governed by an unconventional infinite-randomness critical point featuring activated dynamical scaling. The critical behavior of this transition does not depend on the disorder strength, i.e., it is universal. Close to the disordered critical point, the dynamics is characterized by the nonuniversal power laws typical of a Griffiths phase. We compare our findings to the results of other numerical methods, and we relate them to a general classification of phase transitions in disordered systems based on the rare region dimensionality. PMID:23214768

  18. Characterization of flue gas cleaning residues from European solid waste incinerators: assessment of various Ca-based sorbent processes.

    PubMed

    Bodénan, F; Deniard, Ph

    2003-05-01

    For the first time, a set of samples of European flue gas cleaning residues, mainly from the incineration of municipal solid waste (MSW), has undergone a mineralogical study. The residues are the result of the neutralization of acid flue gases by lime, the predominant method adopted in Europe, using dry and semi-dry washing processes. The study protocol combines physico-chemical analytical techniques (XRD, FTIR, DSC/TGA) and global chemical analysis enabling identification of the chemical composition of the main constituents, particularly chlorinated Ca-based phases, as well as establishment of modal distributions of the represented phases, both crystalline and amorphous. The samples are slightly hydrated and values vary for trapped Cl, S and even CO(2). The main crystalline phases are NaCl, KCl, CaSO(4), CaCO(3), Ca(OH)(2) and calcium hydroxychloride CaOHCl. CaOHCl is the main chlorine phase, regardless of the treatment process, filtration mode, and specific surface of the Ca-based sorbent. This phase develops during neutralization of HCl by excess lime present according to the reaction Ca(OH)(2)+HCl-->CaOHCl+H(2)O, to the detriment of a complete yield involving the two lime OH groups with formation of CaCl(2).2H(2)O. In addition, it seems that gas temperatures above 150 degrees C increase competition between lime-based neutralization of HCl, SO(2) acid flue gases and CO(2) trapping, thus reducing washing efficiency. PMID:12597999

  19. TREATMENT TANK OFF-GAS TESTING FOR THE ENHANCED CHEMICAL CLEANING PROCESS

    SciTech Connect

    Wiersma, B.

    2011-08-29

    The purpose of this activity was to provide a bounding estimate of the volume of hydrogen gas generated during Enhanced Chemical Cleaning (ECC) of residual sludge remaining in a Type I or Type II treatment tank as well as to provide results independent of the sludge volume in the waste tank to be cleaned. Previous testing to support Chemical Cleaning was based on a 20:1 oxalic acid to sludge ratio. Hydrogen gas evolution is the primary safety concern. Sealed vessel coupon tests were performed to estimate the hydrogen generation rate due to corrosion of carbon steel by 2.5 wt.% oxalic acid. These tests determined the maximum instantaneous hydrogen generation rate, the rate at which the generation rate decays, and the total hydrogen generated. These values were quantified based on a small scale methodology similar to the one described in WSRC-STI-2007-00209, Rev. 0. The measured rates support identified Safety Class functions. The tests were performed with ASTM A285 Grade C carbon steel coupons. Bounding conditions were determined for the solution environment. The oxalic acid concentration was 2.5 wt.% and the test temperature was 75 C. The test solution was agitated and contained no sludge simulant. Duplicate tests were performed and showed excellent reproducibility for the hydrogen generation rate and total hydrogen generated. The results showed that the hydrogen generation rate was initially high, but decayed rapidly within a couple of days. A statistical model was developed to predict the instantaneous hydrogen generation rate as a function of exposure time by combining both sets of data. An upper bound on the maximum hydrogen generation rate was determined from the upper 95% confidence limit. The upper bound confidence limit for the hydrogen generation rate is represented by the following equation. ln (G{sub v}) = -8.22-0.0584 t + 0.0002 t{sup 2}. This equation should be utilized to estimate the instantaneous hydrogen generation rate per unit surface area, G

  20. Acid deposition in Maryland. Summary of research and monitoring results compiled through 1991 and a discussion of the 1990 Clean Air Act Amendments. Report for 1991-1992

    SciTech Connect

    Price, R.; Mountain, D.

    1992-10-01

    This is the sixth annual report submitted under Maryland legislative requirements. The report focuses on more than a decade of acid deposition research conducted in Maryland. In addition, the report discusses Title IV - Acid Deposition Control of the 1990 Clean Air Act Amendments (CAAA) and its potential impacts on Maryland.

  1. Cleaning Process Versus Laser-Damage Threshold of Coated Optical Components

    SciTech Connect

    Rigatti, A.L.

    2005-03-31

    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.

  2. Use of formulations based on choline chloride-malonic acid deep eutectic solvent for back end of line cleaning in integrated circuit fabrication

    NASA Astrophysics Data System (ADS)

    Taubert, Jenny

    Interconnection layers fabricated during back end of line processing in semiconductor manufacturing involve dry etching of a low-k material and deposition of copper and metal barriers to create copper/dielectric stacks. After plasma etching steps used to form the trenches and vias in the dielectric, post etch residues (PER) that consist of organic polymer, metal oxides and fluorides, form on top of copper and low-k dielectric sidewalls. Currently, most semiconductor companies use semi aqueous fluoride (SAF) based formulations containing organic solvent(s) for PER removal. Unfortunately, these formulations adversely impact the environmental health and safety (EHS) requirements of the semiconductor industry. Environmentally friendly "green" formulations, free of organic solvents, are preferred as alternatives to remove PER. In this work, a novel low temperature molten salt system, referred as deep eutectic solvent (DES) has been explored as a back end of line cleaning (BEOL) formulation. Specifically, the DES system comprised of two benign chemicals, malonic acid (MA) and choline chloride (CC), is a liquid at room temperature. In certain cases, the formulation was modified by the addition of glacial acetic acid (HAc). Using these formulations, selective removal of three types of PER generated by timed CF4/O2 etching of DUV PR films on Cu was achieved. Type I PER was mostly organic in character (fluorocarbon polymer type) and had a measured thickness of 160 nm. Type II PER was much thinner (25 nm) and consisted of a mixture of organic and inorganic compounds (copper fluorides). Further etching generated 17 nm thick Type III PER composed of copper fluorides and oxides. Experiments were also conducted on patterned structures. Cleaning was performed by immersing samples in a temperature controlled (30 or 40° C) double jacketed vessel for a time between 1 and 5 minutes. Effectiveness of cleaning was characterized using SEM, XPS and single frequency impedance measurements

  3. Polyaniline-Coated Carbon Nanotube Ultrafiltration Membranes: Enhanced Anodic Stability for In Situ Cleaning and Electro-Oxidation Processes.

    PubMed

    Duan, Wenyan; Ronen, Avner; Walker, Sharon; Jassby, David

    2016-08-31

    Electrically conducting membranes (ECMs) have been reported to be efficient in fouling prevention and destruction of aqueous chemical compounds. In the current study, highly conductive and anodically stable composite polyaniline-carbon nanotube (PANI-CNT) ultrafiltration (UF) ECMs were fabricated through a process of electropolymerization of aniline on a CNT substrate under acidic conditions. The resulting PANI-CNT UF ECMs were characterized by scanning electron microscopy, atomic force microscopy, a four-point conductivity probe, cyclic voltammetry, and contact angle goniometry. The utilization of the PANI-CNT material led to significant advantages, including: (1) increased electrical conductivity by nearly an order of magnitude; (2) increased surface hydrophilicity while not impacting membrane selectivity or permeability; and (3) greatly improved stability under anodic conditions. The membrane's anodic stability was evaluated in a pH-controlled aqueous environment under a wide range of anodic potentials using a three-electrode cell. Results indicate a significantly reduced degradation rate in comparison to a CNT-poly(vinyl alcohol) ECM under high anodic potentials. Fouling experiments conducted with bovine serum albumin demonstrated the capacity of the PANI-CNT ECMs for in situ oxidative cleaning, with membrane flux restored to its initial value under an applied potential of 3 V. Additionally, a model organic compound (methylene blue) was electrochemically transformed at high efficiency (90%) in a single pass through the anodically charged ECM. PMID:27525344

  4. Evaluation of post-ashed photoresist cleaning using oxidizing chemistries

    SciTech Connect

    Resnick, P.J.; Matlock, C.A.

    1997-08-01

    The use of sulfuric acid based chemistries for the removal of photoresist ashing residue was investigated. Samples were prepared by ion-implanting patterned, UV-hardened photoresist. The efficacy of post-ash cleaning was determined by measuring organic, metallic, and particulate surface concentrations. Sulfuric-nitric mixtures and sulfuric-hydrogen peroxide mixtures were highly effective for the removal of metallic contaminants. Neither chemistry was very effective for particulate and organic residue. Highly effective overall cleaning was observed when a sulfuric acid based clean was followed with an RCA-type process sequence. Redundant cleans provided no additional benefits. Post-ash cleaning may be simplified by either reducing the number of sulfuric acid based cleans, or for certain post-ash applications, by replacing them with RCA-type processes.

  5. Polyphosphate-containing fluid fertilizers based on wet-process acid and wet-process acid-sulfuric acid mixtures

    SciTech Connect

    Mann, H.C.

    1984-01-01

    In the late 1960s and early 1970s, the Tennessee Valley Authority (TVA) developed and patented a pipe-reactor process that used low-conversion superphosphoric acid to produce a 10-34-0 grade liquid fertilizer that contained about 60 to 70% of the total P/sub 2/O/sub 5/ as polyphosphate. The process was accepted rapidly by the fluid-fertilizer industry and there are now about 125 commercial plants in operation throughout the United States using this technology. In the latter part of 1970, studies were begun to develop a process to use less expensive merchant-grade acid in a pipe reactor. The process that resulted was designed so that it could be retrofitted into the existing 10-34-0 process with some equipment changes. The product was a 9-32-0 grade suspension fertilizer containing about 20% of the total P/sub 2/O/sub 5/ as polyphosphate. In 1981, TVA began operation in a demonstration-scale unit with a design capacity of 20 tons of 9-32-0 suspension per hour. In addition to using the relatively inexpensive anhydrous ammonia and merchant-grade wet-process acid as raw materials, the process was designed to be energy efficient in that all of the heat required to vaporize the ammonia and preheat the merchant-grade acid was obtained from the process.

  6. Cathodic ARC surface cleaning prior to brazing

    SciTech Connect

    Dave, V. R.; Hollis, K. J.; Castro, R. G.; Smith, F. M.; Javernick, D. A.

    2002-01-01

    Surface cleanliness is one the critical process variables in vacuum furnace brazing operations. For a large number of metallic components, cleaning is usually accomplished either by water-based alkali cleaning, but may also involve acid etching or solvent cleaning / rinsing. Nickel plating may also be necessary to ensure proper wetting. All of these cleaning or plating technologies have associated waste disposal issues, and this article explores an alternative cleaning process that generates minimal waste. Cathodic arc, or reserve polarity, is well known for welding of materials with tenacious oxide layers such as aluminum alloys. In this work the reverse polarity effect is used to clean austenitic stainless steel substrates prior to brazing with Ag-28%Cu. This cleaning process is compared to acid pickling and is shown to produce similar wetting behavior as measured by dynamic contact angle experiments. Additionally, dynamic contact angle measurements with water drops are conducted to show that cathodic arc cleaning can remove organic contaminants as well. The process does have its limitations however, and alloys with high titanium and aluminum content such as nickel-based superalloys may still require plating to ensure adequate wetting.

  7. Chemical dynamics of acidity and heavy metals in a mine water-polluted soil during decontamination using clean water.

    PubMed

    Chen, A; Lin, C; Lu, W; Ma, Y; Bai, Y; Chen, H; Li, J

    2010-03-15

    A column leaching experiment was conducted to investigate the chemical dynamics of the percolating water and washed soil during decontamination of an acidic mine water-polluted soil. The results show that leaching of the contaminated soil with clean water rapidly reduced soluble acidity and ion concentrations in the soils. However, only <20% of the total actual acidity in the soil column was eliminated after 30 leaching cycles. It is likely that the stored acidity continues to be released to the percolating water over a long period of time. During the column leaching, dissolved Cu and Pb were rapidly leached out, followed by mobilization of colloidal Cu and Pb from the exchangeable and the oxide-bound fractions as a result of reduced ionic strength in the soil solution. The soluble Fe contained in the soil was rare, probably because the soil pH was not sufficiently low; marked mobility of colloidal Fe took place after the ionic strength of the percolating water was weakened and the mobilized Fe was mainly derived from iron oxides. In contrast with Cu, Pb and Fe, the concentration of leachate Zn and Mn showed a continuously decreasing trend during the entire period of the experiment. PMID:19913356

  8. Gelled acidic well treating composition and process

    SciTech Connect

    Swanson, B.L.

    1981-01-13

    Gelled acidic compositions suitable for either matrix-acidizing or fracture-acidizing of subterranean formations comprising water , a water-dispersible polymer selected from cellulose ethers and polymers of acrylamides, an acid, an aldehyde, and a phenolic compound capable of causing gelation of an aqueous dispersion of the polymer, acid, aldehyde, and phenolic compound are provided. In another embodiment, guar gum, polyvinylpyrrolidone and biopolysaccharides can also be used as the polymeric component in said compositions.

  9. Adsorption and thermal chemistry of formic acid on clean and oxygen-predosed Cu(110) single-crystal surfaces revisited

    NASA Astrophysics Data System (ADS)

    Yao, Yunxi; Zaera, Francisco

    2016-04-01

    The thermal chemistry of formic acid on clean and oxygen-predosed Cu(110) single-crystal surfaces was studied under ultrahigh-vacuum (UHV) conditions by temperature programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS). Key results reported in the past were confirmed, including the partial switchover from H2 to H2O desorption upon oxygen addition on the surface and the development of a second decomposition regime at 420 K, in addition to the one observed at 460 K on the clean substrate. In addition, new observations were added, including the previously missed desorption of H2 at 420 K and the existence of a normal kinetic isotope effect in both TPD peaks. Peak fitting of the XPS data afforded the identification of an asymmetric geometry for the formate intermediate, which was established to form by 200 K, and the presence of coadsorbed molecular formic acid up to the temperatures of decomposition, probably in a second layer and held by hydrogen bonding. Quantitative analysis of the TPD data indicated a one-to-one correspondence between the increase in oxygen coverage beyond θO = 0.5 ML and a decrease in formic acid uptake that mainly manifests itself in a decrease in the decomposition seen in the 460 K TPD peak. All these observations were interpreted in terms of a simple decomposition mechanism involving hydrogen abstraction from adsorbed formate species, possibly aided by coadsorbed oxygen, and a change in reaction activation energy as a function of the structure of the oxygen overlayer, which reverts from a O-c(6 × 2) structure at high oxygen coverages to the O-(2 × 1) order seen at θO = 0.5 ML.

  10. Model development for naphthenic acids ozonation process.

    PubMed

    Al Jibouri, Ali Kamel H; Wu, Jiangning

    2015-02-01

    Naphthenic acids (NAs) are toxic constituents of oil sands process-affected water (OSPW) which is generated during the extraction of bitumen from oil sands. NAs consist mainly of carboxylic acids which are generally biorefractory. For the treatment of OSPW, ozonation is a very beneficial method. It can significantly reduce the concentration of NAs and it can also convert NAs from biorefractory to biodegradable. In this study, a factorial design (2(4)) was used for the ozonation of OSPW to study the influences of the operating parameters (ozone concentration, oxygen/ozone flow rate, pH, and mixing) on the removal of a model NAs in a semi-batch reactor. It was found that ozone concentration had the most significant effect on the NAs concentration compared to other parameters. An empirical model was developed to correlate the concentration of NAs with ozone concentration, oxygen/ozone flow rate, and pH. In addition, a theoretical analysis was conducted to gain the insight into the relationship between the removal of NAs and the operating parameters. PMID:25189805

  11. Development of the LICADO coal cleaning process. Final report, October 1, 1987--April 2, 1990

    SciTech Connect

    Not Available

    1990-07-31

    Development of the liquid carbon dioxide process for the cleaning of coal was performed in batch, variable volume (semi-continuous), and continuous tests. Continuous operation at feed rates up to 4.5 kg/hr (10-lb/hr) was achieved with the Continuous System. Coals tested included Upper Freeport, Pittsburgh, Illinois No. 6, and Middle Kittanning seams. Results showed that the ash and pyrite rejections agreed closely with washability data for each coal at the particle size tested (-200 mesh). A 0.91 metric ton (1-ton) per hour Proof-of-Concept Plant was conceptually designed. A 181 metric ton (200 ton) per hour and a 45 metric ton (50 ton) per hour plant were sized sufficiently to estimate costs for economic analyses. The processing costs for the 181 metric ton (200 ton) per hour and 45 metric ton (50 ton) per hour were estimated to be $18.96 per metric ton ($17.20 per ton) and $11.47 per metric ton ($10.40 per ton), respectively for these size plants. The costs for the 45 metric ton per hour plant are lower because it is assumed to be a fines recovery plant which does not require a grinding circuit of complex waste handling system.

  12. State-of-the-Art Evaluation of Ultra-Clean ULSI Processes^*

    NASA Astrophysics Data System (ADS)

    Fischer-Colbrie, Alice M.

    1996-03-01

    Ultra-clean Si wafer surfaces are critical to the fabrication of ULSI-quality gate oxides. At present, the best methods for removing surface metal impurities exceeds our ability to measure them using traditional methods. New methods are being actively developed to fill this gap. One approach has been to extend the capability of a technique widely used throughout the semiconductor industry, total reflection x-ray fluorescence (TXRF), by using synchrotron radiation. To date, synchrotron radiation total reflection x-ray fluorescence (SR TXRF) has a state-of-the-art transition metal sensitivity of ~ 3 × 10^8/cm^2 (<10 fg) as determined from Fe, Ni, and Zn dip-contaminated standards. This sensitivity is over an order of magnitude better than for an in-house x-ray source. These results have been obtained through the specific development of beam-line optics, detectors and wafer handling protocols. At this time, SR TXRF has been used by Sematech member companies to measure the cleanliness of full wafers (up to 150mm) at various steps in the integrated circuit fabrication process. In addition, SR TXRF results from clean wafers have been compared to conventional TXRF results from wafers which have been prepared by chemically concentrating the impurities. These data show that the higher sensitivity made possible by the synchrotron radiation source is in a useful regime. With the completion of on-going hardware improvements and improved availability of beamtime, this method could be integrated into ULSI process development. ^*Work done in collaboration with: S.S. Laderman, Hewlett-Packard Labs; S. Brennan, A. Waldhauer, N. Takaura, P. Pianetta, Stanford Synchrotron Radiation Laboratory; A. Shimazaki, K. Miyazaki, Toshiba Corp.; I. Cornelissen, M. Meuris, IMEC; D.C. Wherry, S. Barkan, Kevex, Inc; E. Adem, AMD; D. Werho, Motorola, Inc.; M. Zaitz, IBM; J. Rose, DEC; L. Files, Texas Instruments; K. Gupta, Intel; Synchrotron radiation experiments were performed at the Stanford

  13. Final Report of NATO/SPS Pilot Study on Clean Products and Processes (Phase I and II)

    EPA Science Inventory

    Early in 1998 the NATO Committee for Challenges to Modern Society (SPS) (Science for Peace and Security) approved the Pilot Study on Clean Products and Processes for an initial period of five years. The pilot was to provide a forum for member country representatives to discuss t...

  14. Aircraft Materials, Processes, Cleaning and Corrosion Control (Course Outline), Aviation Mechanics 1 (Power and Frame): 9073.01.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    This document presents an outline for a 135-hour course designed to familiarize the beginning student with the basic concepts common to aircraft materials and processes, together with the requirements of proper cleaning and corrosion control as outlined by the Federal Aviation Agency. The aviation airframe and powerplant maintenance technician is…

  15. Impact of different cleaning processes on the laser damage threshold of antireflection coatings for Z-Backlighter optics at Sandia National Laboratories

    SciTech Connect

    Field, Ella; Bellum, John; Kletecka, Damon

    2014-11-06

    We have examined how different cleaning processes affect the laser-induced damage threshold of antireflection coatings for large dimension, Z-Backlighter laser optics at Sandia National Laboratories. Laser damage thresholds were measured after the coatings were created, and again 4 months later to determine which cleaning processes were most effective. There is a nearly twofold increase in laser-induced damage threshold between the antireflection coatings that were cleaned and those that were not cleaned. Aging of the coatings after 4 months resulted in even higher laser-induced damage thresholds. Also, the laser-induced damage threshold results revealed that every antireflection coating had a high defect density, despite the cleaning process used, which indicates that improvements to either the cleaning or deposition processes should provide even higher laser-induced damage thresholds.

  16. Impact of different cleaning processes on the laser damage threshold of antireflection coatings for Z-Backlighter optics at Sandia National Laboratories

    DOE PAGESBeta

    Field, Ella; Bellum, John; Kletecka, Damon

    2014-11-06

    We have examined how different cleaning processes affect the laser-induced damage threshold of antireflection coatings for large dimension, Z-Backlighter laser optics at Sandia National Laboratories. Laser damage thresholds were measured after the coatings were created, and again 4 months later to determine which cleaning processes were most effective. There is a nearly twofold increase in laser-induced damage threshold between the antireflection coatings that were cleaned and those that were not cleaned. Aging of the coatings after 4 months resulted in even higher laser-induced damage thresholds. Also, the laser-induced damage threshold results revealed that every antireflection coating had a high defectmore » density, despite the cleaning process used, which indicates that improvements to either the cleaning or deposition processes should provide even higher laser-induced damage thresholds.« less

  17. Well-ordered polymer nano-fibers with self-cleaning property by disturbing crystallization process

    PubMed Central

    2014-01-01

    Bionic self-cleaning surfaces with well-ordered polymer nano-fibers are firstly fabricated by disturbing crystallization during one-step coating-curing process. Orderly thin (100 nm) and long (5–10 μm) polymer nano-fibers with a certain direction are fabricated by external macroscopic force (Fblow) interference introduced by H2 gas flow, leading to superior superhydrophobicity with a water contact angle (WCA) of 170° and a water sliding angle (WSA) of 0-1°. In contrast, nano-wires and nano-bridges (1–8 μm in length/10-80 nm in width) are generated by “spinning/stretching” under internal microscopic force (FT) interference due to significant temperature difference in the non-uniform cooling medium. The findings provide a novel theoretical basis for controllable polymer “bionic lotus” surface and will further promote practical application in many engineering fields such as drag-reduction and anti-icing. PMID:25114644

  18. Well-ordered polymer nano-fibers with self-cleaning property by disturbing crystallization process.

    PubMed

    Yang, Qin; Luo, Zhuangzhu; Tan, Sheng; Luo, Yimin; Wang, Yunjiao; Zhang, Zhaozhu; Liu, Weimin

    2014-01-01

    Bionic self-cleaning surfaces with well-ordered polymer nano-fibers are firstly fabricated by disturbing crystallization during one-step coating-curing process. Orderly thin (100 nm) and long (5-10 μm) polymer nano-fibers with a certain direction are fabricated by external macroscopic force (F blow) interference introduced by H2 gas flow, leading to superior superhydrophobicity with a water contact angle (WCA) of 170° and a water sliding angle (WSA) of 0-1°. In contrast, nano-wires and nano-bridges (1-8 μm in length/10-80 nm in width) are generated by "spinning/stretching" under internal microscopic force (F T) interference due to significant temperature difference in the non-uniform cooling medium. The findings provide a novel theoretical basis for controllable polymer "bionic lotus" surface and will further promote practical application in many engineering fields such as drag-reduction and anti-icing. PMID:25114644

  19. Well-ordered polymer nano-fibers with self-cleaning property by disturbing crystallization process

    NASA Astrophysics Data System (ADS)

    Yang, Qin; Luo, Zhuangzhu; Tan, Sheng; Luo, Yimin; Wang, Yunjiao; Zhang, Zhaozhu; Liu, Weimin

    2014-07-01

    Bionic self-cleaning surfaces with well-ordered polymer nano-fibers are firstly fabricated by disturbing crystallization during one-step coating-curing process. Orderly thin (100 nm) and long (5-10 μm) polymer nano-fibers with a certain direction are fabricated by external macroscopic force ( F blow) interference introduced by H2 gas flow, leading to superior superhydrophobicity with a water contact angle (WCA) of 170° and a water sliding angle (WSA) of 0-1°. In contrast, nano-wires and nano-bridges (1-8 μm in length/10-80 nm in width) are generated by "spinning/stretching" under internal microscopic force ( F T) interference due to significant temperature difference in the non-uniform cooling medium. The findings provide a novel theoretical basis for controllable polymer "bionic lotus" surface and will further promote practical application in many engineering fields such as drag-reduction and anti-icing.

  20. Brooktrout Lake case study: biotic recovery from acid deposition 20 years after the 1990 Clean Air Act Amendments.

    PubMed

    Sutherland, James W; Acker, Frank W; Bloomfield, Jay A; Boylen, Charles W; Charles, Donald F; Daniels, Robert A; Eichler, Lawrence W; Farrell, Jeremy L; Feranec, Robert S; Hare, Matthew P; Kanfoush, Sharon L; Preall, Richard J; Quinn, Scott O; Rowell, H Chandler; Schoch, William F; Shaw, William H; Siegfried, Clifford A; Sullivan, Timothy J; Winkler, David A; Nierzwicki-Bauer, Sandra A

    2015-03-01

    The Adirondack Mountain region is an extensive geographic area (26,305 km(2)) in upstate New York where acid deposition has negatively affected water resources for decades and caused the extirpation of local fish populations. The water quality decline and loss of an established brook trout (Salvelinus fontinalis [Mitchill]) population in Brooktrout Lake were reconstructed from historical information dating back to the late 1880s. Water quality and biotic recovery were documented in Brooktrout Lake in response to reductions of S deposition during the 1980s, 1990s, and 2000s and provided a unique scientific opportunity to re-introduce fish in 2005 and examine their critical role in the recovery of food webs affected by acid deposition. Using C and N isotope analysis of fish collagen and state hatchery feed as well as Bayesian assignment tests of microsatellite genotypes, we document in situ brook trout reproduction, which is the initial phase in the restoration of a preacidification food web structure in Brooktrout Lake. Combined with sulfur dioxide emissions reductions promulgated by the 1990 Clean Air Act Amendments, our results suggest that other acid-affected Adirondack waters could benefit from careful fish re-introduction protocols to initiate the ecosystem reconstruction of important components of food web dimensionality and functionality. PMID:25621941

  1. The adsorption of acetic acid on clean and oxygen-covered Au/Pd(100) alloy surfaces

    NASA Astrophysics Data System (ADS)

    Li, Zhenjun; Tysoe, Wilfred T.

    2012-12-01

    The adsorption of acetic acid is studied on clean and oxygen-covered Au/Pd(100) alloys as a function of gold content by temperature-programmed desorption and reflection-absorption infrared spectroscopy. Au/Pd(100) forms ordered alloys such that, for gold coverages above ~ 0.5 monolayers, only isolated palladium atoms surrounded by gold nearest neighbors are present. Predominantly molecular acetic acid forms on Au/Pd(100) alloy surfaces for gold coverages greater than ~ 0.56 ML, and desorbs with an activation energy of ~ 59 kJ/mol. Heating this surface also forms some η1-acetate species which decompose to form CO and hydrogen. On alloy surfaces with palladium-palladium bridge sites, η1-acetate species initially form, but rapidly convert into η2-species. They thermally decompose to form CO and hydrogen, with a small portion rehydrogenating to form acetic acid between 280 and 321 K depending on gold coverage. The presence of oxygen on both Pd(100) and Au/Pd(100) alloys facilitates acetate dehydrogenation so that only η2-acetate species form on these surfaces. The presence of oxygen also serves to stabilize the acetate species.

  2. Process for the extraction of strontium from acidic solutions

    DOEpatents

    Horwitz, E. Philip; Dietz, Mark L.

    1994-01-01

    The invention is a process for selectively extracting strontium values from aqueous nitric acid waste solutions containing these and other fission product values. The extractant solution is a macrocyclic polyether in an aliphatic hydrocarbon diluent containing a phase modifier. The process will selectively extract strontium values from nitric acid solutions which are up to 6 molar in nitric acid.

  3. Process for the extraction of strontium from acidic solutions

    DOEpatents

    Horwitz, E.P.; Dietz, M.L.

    1993-01-01

    The invention is a process for selectively extracting strontium values from aqueous nitric acid waste solutions containing these and other fission product values. The extractant solution is a macrocyclic polyether in an aliphatic hydrocarbon diluent containing a phase modifier. The process will selectively extract strontium values from nitric acid solutions which are up to 6 molar in nitric acid.

  4. Process for the extraction of strontium from acidic solutions

    DOEpatents

    Horwitz, E.P.; Dietz, M.L.

    1994-09-06

    The invention is a process for selectively extracting strontium values from aqueous nitric acid waste solutions containing these and other fission product values. The extractant solution is a macrocyclic polyether in an aliphatic hydrocarbon diluent containing a phase modifier. The process will selectively extract strontium values from nitric acid solutions which are up to 6 molar in nitric acid. 4 figs.

  5. Fluidized-Bed Cleaning of Silicon Particles

    NASA Technical Reports Server (NTRS)

    Rohatgi, Naresh K.; Hsu, George C.

    1987-01-01

    Fluidized-bed chemical cleaning process developed to remove metallic impurities from small silicon particles. Particles (250 micrometer in size) utilized as seed material in silane pyrolysis process for production of 1-mm-size silicon. Product silicon (1 mm in size) used as raw material for fabrication of solar cells and other semiconductor devices. Principal cleaning step is wash in mixture of hydrochloric and nitric acids, leaching out metals and carrying them away as soluble chlorides. Particles fluidized by cleaning solution to assure good mixing and uniform wetting.

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

    DOEpatents

    Balachandran, Uthamalingam

    1996-01-01

    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.

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

    DOEpatents

    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.

  8. Purification process for succinic acid produced by fermentation

    SciTech Connect

    Glassner, D.A.; Elankovan, P.; Beacom, D.R.

    1995-12-31

    Succinic acid is a versatile four-carbon dicarboxylic acid. It can be used commercially as an intermediate chemical for the manufacture of 1,4-butanediol, maleic anhydride, and many other chemicals. Succinic acid can be produced by the fermentation of carbohydrates. A complete process for the production and purification of succinic acid from carbohydrates has been developed. The process includes fermentation, desalting electrodialysis, water-splitting electrodialysis, and crystallization to produce a pure crystalline succinic acid. This article will present experimental work performed in the development of this process.

  9. Electric Utility Phase I Acid Rain Compliance Strategies for the Clean Air Act Amendments of 1990

    EIA Publications

    1994-01-01

    The Acid Rain Program is divided into two time periods; Phase I, from 1995 through 1999, and Phase II, starting in 2000. Phase I mostly affects power plants that are the largest sources of SO2 and NOx . Phase II affects virtually all electric power producers, including utilities and nonutilities. This report is a study of the effects of compliance with Phase I regulations on the costs and operations of electric utilities, but does not address any Phase II impacts.

  10. H.R. 474: A Bill to repeal provisions of the Clean Air Act dealing with acid rain. Introduced in the House of Representatives, One Hundred Fourth Congress, First session

    SciTech Connect

    1995-12-31

    The text of this proposed legislation reads as follows: `Section 1. Repeal of Clean Air Act provisions relating to Acid Rain. Title IV of the Clean Air Act (42 U.S.C. 7401 and following), relating to acid deposition control, is hereby repealed.`

  11. Digital processing of SEM images for the assessment of evaluation indexes of cleaning interventions on Pentelic marble surfaces

    SciTech Connect

    Moropoulou, A. Delegou, E.T.; Vlahakis, V.; Karaviti, E.

    2007-11-15

    In this work, digital processing of scanning-electron-microscopy images utilized to assess cleaning interventions applied on the Pentelic marble surfaces of the National Archaeological Museum and National Library in Athens, Greece. Beside mineralogical and chemical characterization that took place by scanning-electron-microscopy with Energy Dispersive X-ray Spectroscopy, the image-analysis program EDGE was applied for estimating three evaluation indexes of the marble micro-structure. The EDGE program was developed by the U.S. Geological Survey for the evaluation of cleaning interventions applied on Philadelphia City Hall. This computer program analyzes scanning-electron-microscopy images of stone specimens cut in cross-section for measuring the fractal dimension of the exposed surfaces, the stone near-surface fracture density, the shape factor (a surface roughness factor) and the friability index which represents the physico-chemical and physico-mechanical stability of the stone surface. The results indicated that the evaluation of the marble surface micro-structure before and after cleaning is achieved by the suggested indexes, while the performance of cleaning interventions on the marble surfaces can be assessed.

  12. ZETA Potential Induced Particle Generation in SC2 Cleaning

    NASA Astrophysics Data System (ADS)

    Mun, Seong Yeol; Yoon, Ki Chae; An, Byeong Woo

    2002-12-01

    After etch and photo resist (PR) strip, particle and byproduct removal treatment is inevitable. SC1/SC2 cleaning process is one of the useful wet cleaning processes to remove them. In most cases, the equipment is batch type (25 or 50 wafers dip into bath) in which particles lifted from edge or backside of wafer move into chip easily by the stream of chemical. Especially in the process of film like Si3N4 with high dielectric constant, the particle issue is more serious. Following SC1 cleaning (main chemical is NH4OH), SC2 cleaning (main chemical is HCl) causes particles to be attached to wafer. The lifted particles in SC1 cleaning are attached to wafer strongly by ZETA potential, which is enhanced when the PH of chemical is lower than 4 (PH of SC2 chemical is about 1.3). SC2 cleaning after SC1 cleaning is not desirable process sequence. But, SC2 chemical is useful for removing metal contamination generated in etch equipment during the etch process. Skipping SC2 cleaning is desirable in the process which metal contamination has no impact on. But, if you want to use SC2 cleaning or other acid chemical (PH below 4) for a guarantee of quality of device, it should be processed before SC1 cleaning.

  13. Computational study of a self-cleaning process on superhydrophobic surface

    NASA Astrophysics Data System (ADS)

    Farokhirad, Samaneh

    All substances around us are bounded by interfaces. In general, interface between different phases of materials are categorized as fluid-fluid, solid-fluid, and solid-solid. Fluid-fluid interfaces exhibit a distinct behavior by adapting their shape in response to external stimulus. For example, a liquid droplet on a substrate can undergo different wetting morphologies depending on topography and chemical composition of the surface. Fundamentally, interfacial phenomena arise at the limit between two immiscible phases, namely interface. The interface dynamic governs, to a great extent, physical processes such as impact and spreading of two immiscible media, and stabilization of foams and emulsions from break-up and coalescence. One of the recent challenging problems in the interface-driven fluid dynamics is the self-propulsion mechanism of droplets by means of different types of external forces such as electrical potential, or thermal Marangoni effect. Rapid removal of self-propelled droplet from the surface is an essential factor in terms of expense and efficiency for many applications including self-cleaning and enhanced heat and mass transfer to save energy and natural resources. A recent study on superhydrophobic nature of micro- and nanostructures of cicada wings offers a unique way for the self-propulsion process with no external force, namely coalescence-induced self-propelled jumping of droplet which can act effectively at any orientation. The biological importance of this new mechanism is associated with protecting such surfaces from long term exposure to colloidal particles such as microbial colloids and virus particles. Different interfacial phenomena can occur after out-of-plane jumping of droplet. If the departed droplet is landed back by gravity, it may impact and spread on the surface or coalesce with another droplet and again self-peopled itself to jump away from the surface. The complete removal of the propelled droplet to a sufficient distance

  14. Bonding effectiveness of self-adhesive and conventional-type adhesive resin cements to CAD/CAM resin blocks. Part 2: Effect of ultrasonic and acid cleaning.

    PubMed

    Kawaguchi, Asuka; Matsumoto, Mariko; Higashi, Mami; Miura, Jiro; Minamino, Takuya; Kabetani, Tomoshige; Takeshige, Fumio; Mine, Atsushi; Yatani, Hirofumi

    2016-01-01

    The present study assessed the effect of ultrasonic and acid cleaning on resin cement bonding to CAD/CAM resin blocks. One of two resin cements, PANAVIA V5 (PV5) or PANAVIA SA CEMENT HANDMIX (PSA), were bonded to one of 24 CAD/CAM blocks (KATANA AVENCIA BLOCK). Each cement group was divided into four subgroups: no cleaning (Ctl), ultrasonic cleaning (Uc), acid cleaning (Ac) and Uc+Ac. Micro-tensile bond strengths (µTBSs) were measured immediately and 1, 3, and 6 months after water storage. Block surfaces after each treatment were analyzed by scanning electron microscopy. Analysis of variance revealed a statistically significant effect for the parameters 'surface treatment' (p<0.001, F=40), 'resin cement' (p<0.001, F=696) and 'water aging' (p<0.001, F=71). The PV5 group exhibited higher µTBS values than the PSA group. Although cleaning after sandblasting was effective in removing residual alumina particles, it did not affect the long-term bonding durability with non-contaminated CAD/CAM resin blocks. PMID:26830822

  15. ANTHROPOGENIC EMISSIONS INVOLVED IN ACIDIC DEPOSITION PROCESSES

    EPA Science Inventory

    The paper describes the methodology that was used to develop the 1985 National Acid Precipitation Assessment Program (NAPAP) Emissions Inventory, including quality control procedures. and summarizes the inventory contents. evelopment of the 1985 inventory required detailed invest...

  16. Use of dilute hydrofluoric acid and deep eutectic solvent systems for back end of line cleaning in integrated circuit fabrication

    NASA Astrophysics Data System (ADS)

    Padmanabhan Ramalekshmi Thanu, Dinesh

    Fabrication of current generation integrated circuits involves the creation of multilevel copper/low-k dielectric structures during the back end of line processing. This is done by plasma etching of low-k dielectric layers to form vias and trenches, and this process typically leaves behind polymer-like post etch residues (PER) containing copper oxides, copper fluorides and fluoro carbons, on underlying copper and sidewalls of low-k dielectrics. Effective removal of PER is crucial for achieving good adhesion and low contact resistance in the interconnect structure, and this is accomplished using wet cleaning and rinsing steps. Currently, the removal of PER is carried out using semi-aqueous fluoride based formulations. To reduce the environmental burden and meet the semiconductor industry's environmental health and safety requirements, there is a desire to completely eliminate solvents in the cleaning formulations and explore the use of organic solvent-free formulations. The main objective of this work is to investigate the selective removal of PER over copper and low-k (Coral and Black DiamondRTM) dielectrics using all-aqueous dilute HF (DHF) solutions and choline chloride (CC) -- urea (U) based deep eutectic solvent (DES) system. Initial investigations were performed on plasma oxidized copper films. Copper oxide and copper fluoride based PER films representative of etch products were prepared by ashing g-line and deep UV photoresist films coated on copper in CF4/O2 plasma. PER removal process was characterized using scanning electron microscopy and X-ray photoelectron spectroscopy and verified using electrochemical impedance spectroscopy measurements. A PER removal rate of ~60 A/min was obtained using a 0.2 vol% HF (pH 2.8). Deaeration of DHF solutions improved the selectivity of PER over Cu mainly due to reduced Cu removal rate. A PER/Cu selectivity of ~20:1 was observed in a 0.05 vol% deaerated HF (pH 3). DES systems containing 2:1 U/CC removed PER at a rate of

  17. Waste Tank Heel Chemical Cleaning Summary

    SciTech Connect

    Barnes, M.J.

    2003-12-02

    At the Savannah River Site in Aiken, South Carolina, there are approximately 40 million gallons of legacy High Level Waste stored in large capacity sub-surface tanks. Twelve of these tanks are single-containment, non-conforming tanks with leaks. These tanks were built in the 1950s. Some of these tanks contain sludge heels and are being considered for near-term removal efforts and vitrification. Currently, only mechanical methods (i.e., pumps) are used to remove the sludge waste with varying degrees of success. To provide for additional levels of removal, chemically-aided techniques are being considered. The objective of the was to collect and evaluate information available on chemical-based methods for removing residual solids from the Site's waste tanks. As part of this study, the team was requested to develop recommendations for chemical treatments to remove residual heels (primarily sludge). Ideally, one agent alone would be efficient at dissolving all residual tank heels and yet satisfy all safety and process concerns. No such chemical cleaning agent was found. The cleaning agents identified from the literature, included oxalic acid, a mixture of oxalic acid and citric acid, a combination of oxalic acid with hydrogen peroxide, nitric acid, formic acid, and organics. A criteria matrix for evaluating the various cleaning agents was developed. The results of the evaluation conclusively support oxalic acid as the cleaning agent of choice for the immediate future. Oxalic acid scored nearly double the next closest cleaning agent. Nitric acid, formic acid, and oxalic acid with hydrogen peroxide were all closely grouped for the next best choice. The mixture of oxalic acid and citric acid rated poorly. Organics rated even more poorly due to large uncertainties in performance and downstream impacts.

  18. The Cleaning of OAB Universal Covers - An Origin of Smut in Aluminum Alloys

    SciTech Connect

    Shen, T

    2002-05-14

    The smut that appeared on the universal covers after the OAB cleaning process consists of sub-micron size aluminum particles originating from the machining of these parts prior to cleaning. The rigorous gross and precision cleanings with Brulin in the OAB cleaning process could not completely wash these fine particles away from the surfaces. However, applying a phosphoric acid etch before the cleaning helped to remove these fine aluminum particles. Experimental results again showed that an acid etching before cleaning is essential in preventing the occurrence of smut in aluminum alloy after gross/precision cleaning. A mechanism, based on the electrostatic {zeta}-potential, is proposed to explain the occurrence of smut that is often encountered during the cleaning of aluminum alloys.

  19. ENVIRONMENTAL AND ECONOMIC COMPARISON OF ADVANCED PROCESSES FOR CONVERSION OF COAL AND BIOMASS INTO CLEAN ENERGY

    EPA Science Inventory

    Biomass and coal conversion into clean energy is compared on an economic and environmental basis in three regional scenarios: (1) electric power from direct combustion of wood versus conventional coal combustion in the South Central U.S., (2) synthetic pipeline gas from anaerobic...

  20. DEVELOPMENT OF A NEW GRAVITY SEDIMENTATION PROCESS FOR DEWATERING FLUE GAS CLEANING WASTES

    EPA Science Inventory

    The report gives results of a project to develop and test a novel system for dewatering flue gas cleaning (FGC) wastes at the pilot plant level. In this new system, the clarification and thickening functions are conducted in separate, but interconnected, pieces of equipment. The ...

  1. Impact of different cleaning processes on the laser damage threshold of antireflection coatings for Z-Backlighter optics at Sandia National Laboratories

    NASA Astrophysics Data System (ADS)

    Field, Ella; Bellum, John; Kletecka, Damon

    2014-12-01

    We have examined how three different cleaning processes affect the laser-induced damage threshold (LIDT) of antireflection coatings for large dimension, Z-Backlighter laser optics at Sandia National Laboratories. Laser damage thresholds were measured after the coatings were created, and again 4 months later to determine which cleaning processes were most effective. Coatings that received cleaning exhibited the highest LIDTs compared to coatings that were not cleaned. In some cases, there is nearly a twofold increase in the LIDT between the cleaned and uncleaned coatings (19.4 J/cm2 compared to 39.1 J/cm2). Higher LIDTs were realized after 4 months of aging. The most effective cleaning process involved washing the coated surface with mild detergent, and then soaking the optic in a mixture of ethyl alcohol and deionized water. Also, the laser damage results indicate that the presence of nonpropagating (NP) damage sites dominates the LIDTs of almost every optic, despite the cleaning process used. NP damage sites can be attributed to defects such as nodules in the coating or surface contamination, which suggests that pursuing further improvements to the deposition or cleaning processes are worthwhile to achieve even higher LIDTs.

  2. Advanced Acid Gas Separation Technology for Clean Power and Syngas Applications

    SciTech Connect

    Amy, Fabrice; Hufton, Jeffrey; Bhadra, Shubhra; Weist, Edward; Lau, Garret; Jonas, Gordon

    2015-06-30

    Air Products has developed an acid gas removal technology based on adsorption (Sour PSA) that favorably compares with incumbent AGR technologies. During this DOE-sponsored study, Air Products has been able to increase the Sour PSA technology readiness level by successfully operating a two-bed test system on coal-derived sour syngas at the NCCC, validating the lifetime and performance of the adsorbent material. Both proprietary simulation and data obtained during the testing at NCCC were used to further refine the estimate of the performance of the Sour PSA technology when expanded to a commercial scale. In-house experiments on sweet syngas combined with simulation work allowed Air Products to develop new PSA cycles that allowed for further reduction in capital expenditure. Finally our techno economic analysis of the use the Sour PSA technology for both IGCC and coal-to-methanol applications suggests significant improvement of the unit cost of electricity and methanol compared to incumbent AGR technologies.

  3. Steam gasification of acid-hydrolysis biomass CAHR for clean syngas production.

    PubMed

    Chen, Guanyi; Yao, Jingang; Yang, Huijun; Yan, Beibei; Chen, Hong

    2015-03-01

    Main characteristics of gaseous product from steam gasification of acid-hydrolysis biomass CAHR have been investigated experimentally. The comparison in terms of evolution of syngas flow rate, syngas quality and apparent thermal efficiency was made between steam gasification and pyrolysis in the lab-scale apparatus. The aim of this study was to determine the effects of temperature and steam to CAHR ratio on gas quality, syngas yield and energy conversion. The results showed that syngas and energy yield were better with gasification compared to pyrolysis under identical thermal conditions. Both high gasification temperature and introduction of proper steam led to higher gas quality, higher syngas yield and higher energy conversion efficiency. However, excessive steam reduced hydrogen yield and energy conversion efficiency. The optimal value of S/B was found to be 3.3. The maximum value of energy ratio was 0.855 at 800°C with the optimal S/B value. PMID:25553562

  4. Process for the recovery of strontium from acid solutions

    DOEpatents

    Horwitz, E. Philip; Dietz, Mark L.

    1992-01-01

    The invention is a process for selectively extracting strontium and technetium values from aqueous nitric acid waste solutions containing these and other fission product values. The extractant is a macrocyclic polyether in a diluent which is insoluble in water, but which will itself dissolve a small amount of water. The process will extract strontium and technetium values from nitric acid solutions which are up to 6 molar in nitric acid.

  5. Process for the recovery of strontium from acid solutions

    DOEpatents

    Horwitz, E.P.; Dietz, M.L.

    1992-03-31

    The invention is a process for selectively extracting strontium and technetium values from aqueous nitric acid waste solutions containing these and other fission product values. The extractant is a macrocyclic polyether in a diluent which is insoluble in water, but which will itself dissolve a small amount of water. The process will extract strontium and technetium values from nitric acid solutions which are up to 6 molar in nitric acid. 5 figs.

  6. Process for the recovery of strontium from acid solutions

    SciTech Connect

    Horwitz, E.P.; Dietz, M.L.

    1990-12-31

    The invention is a process for selectively extracting strontium and technetium values from aqueous nitric acid waste solutions containing these and other fission product values. The extractant is a macrocyclic polyether in a diluent which is insoluble in water, but which will itself dissolve a small amount of water. The process will extract strontium and technetium values from nitric acid solutions which are up to 6 molar in nitric acid.

  7. Processes to remove acid forming gases from exhaust gases

    DOEpatents

    Chang, S.G.

    1994-09-20

    The present invention relates to a process for reducing the concentration of NO in a gas, which process comprises: (A) contacting a gas sample containing NO with a gaseous oxidizing agent to oxidize the NO to NO[sub 2]; (B) contacting the gas sample of step (A) comprising NO[sub 2] with an aqueous reagent of bisulfite/sulfite and a compound selected from urea, sulfamic acid, hydrazinium ion, hydrazoic acid, nitroaniline, sulfanilamide, sulfanilic acid, mercaptopropanoic acid, mercaptosuccinic acid, cysteine or combinations thereof at between about 0 and 100 C at a pH of between about 1 and 7 for between about 0.01 and 60 sec; and (C) optionally contacting the reaction product of step (A) with conventional chemical reagents to reduce the concentrations of the organic products of the reaction in step (B) to environmentally acceptable levels. Urea or sulfamic acid are preferred, especially sulfamic acid, and step (C) is not necessary or performed. 16 figs.

  8. Clean surface processing of rubrene single crystal immersed in ionic liquid by using frequency modulation atomic force microscopy

    SciTech Connect

    Yokota, Yasuyuki; Hara, Hisaya; Morino, Yusuke; Bando, Ken-ichi; Imanishi, Akihito; Fukui, Ken-ichi; Uemura, Takafumi; Takeya, Jun

    2014-06-30

    Surface processing of a rubrene single crystal immersed in ionic liquids is valuable for further development of low voltage transistors operated by an electric double layer. We performed a precise and clean surface processing based on the tip-induced dissolution of rubrene molecules at the ionic liquid/rubrene single crystal interfaces by using frequency modulation atomic force microscopy. Molecular resolution imaging revealed that the tip-induced dissolution proceeded via metastable low density states derived from the anisotropic intermolecular interactions within the crystal structure.

  9. Knack for reticle cleaning

    NASA Astrophysics Data System (ADS)

    Takahashi, Masumi; Handa, Hitoshi; Shirai, Hisatsugu

    2000-07-01

    Cleaning is one of the most important processes in mask making, because it decides final quality. In cleaning process, it is necessary for reticle cleanliness to not only remove particles from reticle but also prevent adsorption and re-deposition onto reticle. There is the knack for reticle cleaning, and we introduce three keys in this paper. The first key is the rinse after chemical treatment. By the rinse sequence modification, the cleaner was refined and the particle removal ability was improved. The second key is quality control to grasp the situation of cleaner. By the daily check, cleaner's abnormal condition is found at an early stage, quick action is taken, and then stable cleaning quality is kept every day. And the third key is proper choice of cleaners. We have adopted pre-cleaning process and selected the adequate cleaner for each cleaning level and improved cleaning yield and quality.

  10. Actual-Waste Tests of Enhanced Chemical Cleaning for Retrieval of SRS HLW Sludge Tank Heels and Decomposition of Oxalic Acid - 12256

    SciTech Connect

    Martino, Christopher J.; King, William D.; Ketusky, Edward T.

    2012-07-01

    Savannah River National Laboratory conducted a series of tests on the Enhanced Chemical Cleaning (ECC) process using actual Savannah River Site waste material from Tanks 5F and 12H. Testing involved sludge dissolution with 2 wt% oxalic acid, the decomposition of the oxalates by ozonolysis (with and without the aid of ultraviolet light), the evaporation of water from the product, and tracking the concentrations of key components throughout the process. During ECC actual waste testing, the process was successful in decomposing oxalate to below the target levels without causing substantial physical or chemical changes in the product sludge. During ECC actual waste testing, the introduction of ozone was successful in decomposing oxalate to below the target levels. This testing did not identify physical or chemical changes in the ECC product sludge that would impact downstream processing. The results from these tests confirm observations made by AREVA NP during larger scale testing with waste simulants. This testing, however, had a decreased utilization of ozone, requiring approximately 5 moles of ozone per mole of oxalate decomposed. Decomposition of oxalates in sludge dissolved in 2 wt% OA to levels near 100 ppm oxalate using ECC process conditions required 8 to 12.5 hours without the aid of UV light and 4.5 to 8 hours with the aid of UV light. The pH and ORP were tracked during decomposition testing. Sludge components were tracked during OA decomposition, showing that most components have the highest soluble levels in the initial dissolved sludge and early decomposition samples and exhibit lower soluble levels as OA decomposition progresses. The Deposition Tank storage conditions that included pH adjustment to approximately 1 M free hydroxide tended to bring the soluble concentrations in the ECC product to nearly the same level for each test regardless of storage time, storage temperature, and contact with other tank sludge material. (authors)

  11. IMPROVED PROCESSES TO REMOVE NAPHTHENIC ACIDS

    SciTech Connect

    Aihua Zhang; Qisheng Ma; Kangshi Wang, William A. Goddard, Yongchun Tang

    2005-05-05

    In the second year of this project, we continued our effort to develop low temperature decarboxylation catalysts and investigate the behavior of these catalysts at different reaction conditions. We conducted a large number of dynamic measurements with crude oil and model compounds to obtain the information at different reaction stages, which was scheduled as the Task2 in our work plan. We developed a novel adsorption method to remove naphthenic acid from crude oil using naturally occurring materials such as clays. Our results show promise as an industrial application. The theoretical modeling proposed several possible reaction pathways and predicted the reactivity depending on the catalysts employed. From all of these studies, we obtained more comprehensive understanding about catalytic decarboxylation and oil upgrading based on the naphthenic acid removal concept.

  12. The research on conformal acid etching process of glass ceramic

    NASA Astrophysics Data System (ADS)

    Wang, Kepeng; Guo, Peiji

    2014-08-01

    A series of experiments have been done to explore the effect of different conditions on the hydrofluoric acid etching. The hydrofluoric acid was used to etch the glass ceramic called "ZERODUR", which is invented by SCHOTT in Germany. The glass ceramic was processed into cylindrical samples. The hydrofluoric acid etching was done in a plastic beaker. The concentration of hydrofluoric acid and the etching time were changed to measure the changes of geometric tolerance and I observed the surface using a microscope in order to find an appropriate condition of hydrofluoric acid etching.

  13. Micro-shear bond strength and surface micromorphology of a feldspathic ceramic treated with different cleaning methods after hydrofluoric acid etching

    PubMed Central

    STEINHAUSER, Henrique Caballero; TURSSI, Cecília Pedroso; FRANÇA, Fabiana Mantovani Gomes; do AMARAL, Flávia Lucisano Botelho; BASTING, Roberta Tarkany

    2014-01-01

    Objective The aim of this study was to evaluate the effect of feldspathic ceramic surface cleaning on micro-shear bond strength and ceramic surface morphology. Material and Methods Forty discs of feldspathic ceramic were prepared and etched with 10% hydrofluoric acid for 2 minutes. The discs were randomly distributed into five groups (n=8): C: no treatment, S: water spray + air drying for 1 minute, US: immersion in ultrasonic bath for 5 minutes, F: etching with 37% phosphoric acid for 1 minute, followed by 1-minute rinse, F+US: etching with 37% phosphoric acid for 1 minute, 1-minute rinse and ultrasonic bath for 5 minutes. Composite cylinders were bonded to the discs following application of silane and hydrophobic adhesive for micro-shear bond strength testing in a universal testing machine at 0.5 mm/min crosshead speed until failure. Stereomicroscopy was used to classify failure type. Surface micromorphology of each treatment type was evaluated by scanning electron microscopy at 500 and 2,500 times magnification. Results One-way ANOVA test showed no significant difference between treatments (p=0.3197) and the most common failure types were cohesive resin cohesion followed by adhesive failure. Micro-shear bond strength of the feldspathic ceramic substrate to the adhesive system was not influenced by the different surface cleaning techniques. Absence of or less residue was observed after etching with hydrofluoric acid for the groups US and F+US. Conclusions Combining ceramic cleaning techniques with hydrofluoric acid etching did not affect ceramic bond strength, whereas, when cleaning was associated with ultrasound, less residue was observed. PMID:24676577

  14. Plasma Cleaning

    NASA Technical Reports Server (NTRS)

    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.

  15. The role of the U.S. Clean Coal Technology Program in implementing the objectives of the joint Canada-U.S. acid rain mitigation initiative

    SciTech Connect

    Baldwin, A.L.; Smith, D.N.; Mann, A.W.; McIlvried, H.G.; Russell, D.L. Sr.

    1997-12-31

    The Clean Coal Technology (CCT) Program was initiated by the US Department of Energy (DOE) in part as a response to the 1986 Joint Report of the US and Canadian Special Envoys on Acid Rain, with a particular focus on coal-burning electric power plants. The fist three solicitations of the CCT Program were aimed primarily at mitigating the potential impacts of acid rain. Subsequently, the Clean Air Act Amendments of 1990 established emission reduction targets for SO{sub 2} and No{sub x}, which influenced the goals of the last two CCT Program. This paper provides an overview of the CCT Program and reports the significant results, with emphasis on emissions reduction as well as their impact on ozone formation.

  16. Manufacturing Assessment of an XeF{sub 2} In-Situ Clean Process for Mitigation of Species Cross Contamination

    SciTech Connect

    Dunn, James P.; Rolland, James L.; Lundquist, Paul; Bishop, Steve

    2008-11-03

    The residue buildup in an ion source can be energetically transported down the ion implanter beamline delivering unwanted dopants to the target area. Of particular concern are contaminants within one AMU of the target species such as {sup 50}PF{sup +} in a {sup 49}BF{sub 2}{sup +} beam causing counter-doping dose errors. Significant beam currents attributable to memory effect have been observed more than an hour after the species gas has been changed. This paper shows how Atmel Corporation, Colorado Springs, Colorado evaluated a new XeF{sub 2} in-situ clean process as an effective means of reducing the risk of species cross contamination.

  17. Cygnus: Electrochemical cleaning

    SciTech Connect

    Simon, G.G.; Sokcic-Kostic, M.; Vujic, J.; Solly, F.; Johnson, D.; Philipp, D.

    2000-07-01

    Electrochemical cleaning, commonly referred to as electropolishing, can be used to remove surface contamination by dissolving the underlying metal matrix. This is accomplished in the Cygnus process by passing an electric current through a dilute, acidic electrolyte. In the operation, the surface is polished, thereby removing contamination and irregularities to prevent recontamination. Mechanical decontamination processes, by comparison, leave the surface layer distorted, highly stressed, and contaminated with process media. Techniques employing grinding and particle impingement rework the surface of malleable metals such as stainless steel, folding the contamination into pockets where material is released for uncontrolled use. Solway, Ltd., developed the method to be more effective with respect to waste reduction and cost-effectiveness. Together with NUKEM Nuklear, the method was improved for a decontamination procedure in nuclear technology. One of the applications was the decontamination work at KRN Grundremmingen in Germany. The intensive work has shown that the method is suitable for decontamination services in both defense and commercial areas.

  18. Modeling the continuous lactic acid production process from wheat flour.

    PubMed

    Gonzalez, Karen; Tebbani, Sihem; Lopes, Filipa; Thorigné, Aurore; Givry, Sébastien; Dumur, Didier; Pareau, Dominique

    2016-01-01

    A kinetic model of the simultaneous saccharification, protein hydrolysis, and fermentation (SSPHF) process for lactic acid production from wheat flour has been developed. The model describes the bacterial growth, substrate consumption, lactic acid production, and maltose hydrolysis. The model was fitted and validated with data from SSPHF experiments obtained under different dilution rates. The results of the model are in good agreement with the experimental data. Steady state concentrations of biomass, lactic acid, glucose, and maltose as function of the dilution rate were predicted by the model. This steady state analysis is further useful to determine the operating conditions that maximize lactic acid productivity. PMID:26399412

  19. Process for producing peracids from aliphatic hydroxy carboxylic acids

    DOEpatents

    Chum, H.L.; Palasz, P.D.; Ratcliff, M.A.

    1984-12-20

    A process is described for producing peracids from lactic acid-containing solutions derived from biomass processing systems. It consists of adjusting the pH of the solution to about 8 to 9 and removing alkaline residue fractions therefrom to form a solution comprised substantially of lower aliphatic hydroxy acids. The solution is oxidized to produce volatile lower aliphatic aldehydes. The aldehydes are removed as they are generated and converted to peracids.

  20. Process for producing peracids from aliphatic hydroxy carboxylic acids

    DOEpatents

    Chum, Helena L.; Ratcliff, Matthew A.; Palasz, Peter D.

    1986-01-01

    A process for producing peracids from lactic acid-containing solutions derived from biomass processing systems comprising: adjusting the pH of the solution to about 8-9 and removing alkaline residue fractions therefrom to form a solution comprised substantially of lower aliphatic hydroxy acids; oxidizing the solution to produce volatile lower aliphatic aldehydes; removing said aldehydes as they are generated; and converting said aldehydes to peracids.

  1. Steam generators secondary side chemical cleaning at Point Lepreau using the Siemens high temperature process

    SciTech Connect

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

    1997-02-01

    This paper describes the chemical cleaning of the four steam generators at the Point Lepreau facility, which was accomplished as a part of a normal service outage. The steam generators had been in service for twelve years. Sludge samples showed the main elements were Fe, P and Na, with minor amounts of Ca, Mg, Mn, Cr, Zn, Cl, Cu, Ni, Ti, Si, and Pb, 90% in the form of Magnetite, substantial phosphate, and trace amounts of silicates. The steam generators were experiencing partial blockage of broached holes in the TSPs, and corrosion on tube ODs in the form of pitting and wastage. In addition heat transfer was clearly deteriorating. More than 1000 kg of magnetite and 124 kg of salts were removed from the four steam generators.

  2. Black silicon with self-cleaning surface prepared by wetting processes

    PubMed Central

    2013-01-01

    This paper reports on a simple method to prepare a hydrophobic surface on black silicon, which is fabricated by metal-assisted wet etching. To increase the reaction rate, the reaction device was placed in a heat collection-constant temperature type magnetic stirrer and set at room temperature. It was demonstrated that the micro- and nanoscale spikes on the black silicon made the surface become hydrophobic. As the reaction rate increases, the surface hydrophobicity becomes more outstanding and presents self-cleaning until the very end. The reflectance of the black silicon is drastically suppressed over a broad spectral range due to the unique geometry, which is effective for the enhancement of absorption. PMID:23941184

  3. Improve the laser damage resistance of fused silica by wet surface cleaning and optimized HF etch process

    NASA Astrophysics Data System (ADS)

    Jiang, Xiaolong; Liu, Ying; Rao, Huanle; Fu, Shaojun

    2013-07-01

    Fabrication-induced metal contaminations and subsurface damage are generally identified as the laser damage initiators that are responsible for the laser induced damage in fused silica. In this paper, the removal of those two initiators are realized by two methods: wet chemical surface cleaning and optimized HF-based etch process. Two kinds of chemical leaching are used to removing the Ce and other metal impurities respectively. In order prevent the redeposition of the reactive byproducts during HF etch process, we optimized the traditional HF etch process in two ways: absence of NH4F in etch solution and presence of megasonic and ultrasonic agitation during and after etch respectively. And laser damage tests show that these two treatments greatly improve the laser damage resistance of fused silica.

  4. Recent advances in lactic acid production by microbial fermentation processes.

    PubMed

    Abdel-Rahman, Mohamed Ali; Tashiro, Yukihiro; Sonomoto, Kenji

    2013-11-01

    Fermentative production of optically pure lactic acid has roused interest among researchers in recent years due to its high potential for applications in a wide range of fields. More specifically, the sharp increase in manufacturing of biodegradable polylactic acid (PLA) materials, green alternatives to petroleum-derived plastics, has significantly increased the global interest in lactic acid production. However, higher production costs have hindered the large-scale application of PLA because of the high price of lactic acid. Therefore, reduction of lactic acid production cost through utilization of inexpensive substrates and improvement of lactic acid production and productivity has become an important goal. Various methods have been employed for enhanced lactic acid production, including several bioprocess techniques facilitated by wild-type and/or engineered microbes. In this review, we will discuss lactic acid producers with relation to their fermentation characteristics and metabolism. Inexpensive fermentative substrates, such as dairy products, food and agro-industrial wastes, glycerol, and algal biomass alternatives to costly pure sugars and food crops are introduced. The operational modes and fermentation methods that have been recently reported to improve lactic acid production in terms of concentrations, yields, and productivities are summarized and compared. High cell density fermentation through immobilization and cell-recycling techniques are also addressed. Finally, advances in recovery processes and concluding remarks on the future outlook of lactic acid production are presented. PMID:23624242

  5. Process for obtaining silicon from fluosilicic acid

    DOEpatents

    Sanjurjo, Angel

    1984-04-10

    Process for producing low cost, high purity solar grade Si wherein a reduction reaction, preferably the reduction of SiF.sub.4, by an alkali metal (Na preferred) is carried out by jetting a spray of reactants into a reaction chamber at a rate and temperature which causes the reaction to take place far enough away from the entry region to avoid plugging of reactants at the entry region and wherein separation in the melt is carried out continuously from the reaction and the Si can be cast directly from the melt.

  6. Rare regions and Griffiths singularities at a clean critical point: the five-dimensional disordered contact process.

    PubMed

    Vojta, Thomas; Igo, John; Hoyos, José A

    2014-07-01

    We investigate the nonequilibrium phase transition of the disordered contact process in five space dimensions by means of optimal fluctuation theory and Monte Carlo simulations. We find that the critical behavior is of mean-field type, i.e., identical to that of the clean five-dimensional contact process. It is accompanied by off-critical power-law Griffiths singularities whose dynamical exponent z' saturates at a finite value as the transition is approached. These findings resolve the apparent contradiction between the Harris criterion, which implies that weak disorder is renormalization-group irrelevant, and the rare-region classification, which predicts unconventional behavior. We confirm and illustrate our theory by large-scale Monte Carlo simulations of systems with up to 70(5) sites. We also relate our results to a recently established general relation between the Harris criterion and Griffiths singularities [Phys. Rev. Lett. 112, 075702 (2014)], and we discuss implications for other phase transitions. PMID:25122283

  7. Radiation Chemistry of Acetohydroxamic Acid in the UREX Process

    SciTech Connect

    Karraker, D.G.

    2002-07-31

    The UREX process is being developed to process irradiated power reactor elements by dissolution in nitric acid and solvent extraction by a variation of the PUREX process.1 Rather than recovering both U and Pu, as in Purex, only U will be recovered by solvent extraction, hence the name ''UREX.'' A complexing agent, acetohydroxamic acid (AHA), will be added to the scrub stream to prevent the extraction of Pu(IV) and Np(VI). AHA (CH3C=ONHOH) is decomposed to gaseous products in waste evaporation, so no solid waste is generated by its addition. AHA is hydrolyzed in acid solution to acetic acid and hydroxylamine at a rate dependent on the acid concentration.2-4 The fuel to be processed is ca 40 years cooled, 30,000-50,000 MWD/MT material; although only a few fission products remain, the Pu isotopes and 241Am generate a radiation field estimated to be 2.6E+02R during processing. (see Appendix for calculation.) This study was conducted to determine the effect of this level of radiation on the stability of AHA during processing.

  8. Products of the radical initiated oxidation of model solid and liquid organic acid particles in simulated "clean" and "polluted" environments.

    NASA Astrophysics Data System (ADS)

    Renbaum, L. H.; Smith, G. D.

    2009-05-01

    Using a flow tube reactor coupled to a chemical ionization mass spectrometer, the Cl-initiated oxidation of solid and supercooled liquid organic acid particles were investigated at 293 K. In creating aerosols of species which are able to be supercooled or solid at room temperature, it is possible to distinguish the effect of phase on particle reactivity and product formation. In a clean atmosphere, where there are negligible concentrations of NOx, the primary fate of peroxy radicals (formed from H-abstraction by Cl and OH radicals in the presence of O2) are their reactions to form ketone and alcohol products. These products are then able to undergo further oxidation to form multiply oxidized products. The formation of low-molecular weight volatile species may also be important in the oxidative aging of organic aerosols, however neither the mechanism of their formation nor their formation yields are well understood. We have shown that, for equivalent Cl exposures, more multiply-oxidized species as well as more low-molecular-weight species were created from the oxidation of solid particles than from liquid particles. The findings from these studies suggest that slower diffusion of the oxidation products in solid particles confines them to the surface where they continue to react with Cl radicals producing more-highly- functionalized products which may decompose more readily. By introducing nitric oxide to the flow tube reaction system, we show that in a polluted atmosphere, where NOx is present in significant concentrations, organic nitrate formation may become important on the surface of solid particles but not liquid particles as the RO2 are confined to the surface of solid particles (causing a enhanced localized concentration of RO2) where they may then react with ambient nitric oxide through the reaction RO2 + NO → RO2NO* → RONO2. These experiments of these model systems indicate that particle phase could be important in determining how organic aerosols

  9. Tetrachloroethene recovery and hazard reduction of spent powders from dry cleaning process.

    PubMed

    Petrucci, Elisabetta; Scarsella, Marco; De Filippis, Paolo; Di Palma, Luca

    2015-04-01

    Dry cleaning facilities using perchloroethylene produce a solid waste consisting of spent filtering powders with a high content of residual perchloroethylene, together with dyes and non-volatile residues. Untreated spent powders, classified as hazardous waste, cannot be disposed in landfill and incineration represents the only viable alternative. In this study, together with a full characterisation of the waste, the removal and recovery of the residual perchloroethylene by means of different heat treatments was investigated. In particular, tests of distillation and stripping with air and steam were carried out, evaluating the effectiveness of the treatments by quantifying the residual perchloroethylene in the samples treated. The results obtained show that the spent filtering powders contained about 25% wt. of perchloroethylene and that the maximum perchloroethylene recovery was obtained by steam stripping; approximately 98% after only 50 minutes. However, this treatment accounted for the production of a liquid mixture containing perchloroethylene and of a solid waste that required a further washing with boiling water to decrease the residual organic content below the eligibility criteria for landfill disposal. PMID:25690329

  10. Application of ultrasonic techniques to chemical coal cleaning processes. Final report, April 15, 1980-August 15, 1981. [Ultrasonic augmentation

    SciTech Connect

    Tarpley, W.B. Jr.; Twesme, E.N.; Howard, P.L.; Moulder, G.R.

    1981-08-01

    Ultrasonic activation was applied to several coal cleaning processes, including chlorinolysis, oxydesulfurization, and sodium hypochlorite leaching, in small-scale batch treatment processing of Illinois No. 6, Lower Kittanning, and Western Kentucky No. 11 coals. In all cases, ultrasonic energy application demonstrated effects that would translate in production to processing efficiencies and/or capital equipment savings. Specifically, in the chlorinolysis reaction, pyritic sulfur was removed 23 times faster with ultrasonics than without it. (Organic sulfur could not be removed from the coal examined with or without ultrasonics in the chlorinolysis process). In sodium hypochlorite leaching, the total sulfur extraction rate was 3 times faster with ultrasonics. Two separate benefits were seen with oxydesulfurization: ultrasonics doubled the reaction rate and at slightly accelerated rates allowed a pressure reduction from 960 to 500 psi, which would be a significant cost efficiency in production. With these results, it was recommended that ultrasonic processing be investigated with a process involving interactions similarly amenable to ultrasonic enhancement, i.e., molten salt leaching, which is reported to have the potential not only for more extensive sulfur extraction than the other experimental processes, but for ash removal as well.

  11. Cryogenic process for fractionally removing acidic gases from gas mixtures

    SciTech Connect

    Gazzi, L.; Cotone, G.; Ginnasi, A.; Rescalli, C.; Soldati, G.; Vetere, A.

    1985-07-16

    A process is described for stripping acidic gases, mainly hydrogen sulphide and carbon dioxide, from natural gas or synthesis gas, especially when the percentages of such acidic gases are high and the conventional processes become economically objectionable. The process is based on the use of a number of selective solvents, generally belonging to the class of esters, ethers, mixed ester-ethers and lactones, in combination with sequential absorbing cycles which start from the stripping of hydrogen sulphide, and comprise the regeneration of the solvents used by several expansion cycles: H2S and CO2 are recovered and the regenerated solvents recycled.

  12. How Clean is the Processing Environment and Can We Fix It?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research from our laboratories has shown that shell egg processing facilities should enhance processing plant sanitation practices. A survey of shell egg processing facilities located in the southeastern US found no differences in aerobic bacteria and Enterobacteriaceae levels on plant surfaces bef...

  13. ENVIRONMENTAL TECHNOLOGY INITIATIVE: CHEMICAL-FREE CLEANING OF SEMICONDUCTORS BY THE RADIANCE PROCESS

    EPA Science Inventory

    The Radiance Process is a patented dry process for removing contaminants from surfaces. It uses light, usually from a pulsed laser and a gas inert to the surface, to entrain released contaminants. The focus of this effort is to assess the applicability of the Radiance Process t...

  14. Online process control of acidic texturisation baths with ion chromatography.

    PubMed

    Zimmer, Martin; Oltersdorf, Antje; Rentsch, Jochen

    2009-12-15

    Etching of silicon with mixtures of hydrofluoric acid and nitric acid is a widely used process in silicon solar cell fabrication. One precondition for an optimized usage of the acidic etching baths is the exact knowledge of the chemical bath composition. In this paper, we investigated a fast and online-capable method for the total analysis of all bath constituents by ion chromatography. The chromatographical system consists of a low-volume injection valve, which injects the concentrated samples directly into the KOH-based eluent. After separation and detection of nitrate and fluoride, a post-column derivatization with sodium molybdate is applied to detect the hexafluorosilicic acid, which enriches in the texturisation bath during the etching process. The results of the presented approach are discussed and compared with already published chromatographical and titration methods found in literature. PMID:19836511

  15. Diaromatic sulphur-containing 'naphthenic' acids in process waters.

    PubMed

    West, Charles E; Scarlett, Alan G; Tonkin, Andrew; O'Carroll-Fitzpatrick, Devon; Pureveen, Jos; Tegelaar, Erik; Gieleciak, Rafal; Hager, Darcy; Petersen, Karina; Tollefsen, Knut-Erik; Rowland, Steven J

    2014-03-15

    Polar organic compounds found in industrial process waters, particularly those originating from biodegraded petroleum residues, include 'naphthenic acids' (NA). Some NA have been shown to have acute toxicity to fish and also to produce sub-lethal effects. Whilst some of these toxic effects are produced by identifiable carboxylic acids, acids such as sulphur-containing acids, which have been detected, but not yet identified, may produce others. Therefore, in the present study, the sulphur-containing acids in oil sands process water were studied. A fraction (ca 12% by weight of the total NA containing ca 1.5% weight sulphur) was obtained by elution of methylated NA through an argentation solid phase extraction column with diethyl ether. This was examined by multidimensional comprehensive gas chromatography-mass spectrometry (GCxGC-MS) in both nominal and high resolution mass accuracy modes and by GCxGC-sulphur chemiluminescence detection (GCxGC-SCD). Interpretation of the mass spectra and retention behaviour of methyl esters of several synthesised sulphur acids and the unknowns allowed delimitation of the structures, but not complete identification. Diaromatic sulphur-containing alkanoic acids were suggested. Computer modelling of the toxicities of some of the possible acids suggested they would have similar toxicities to one another and to dehydroabietic acid. However, the sulphur-rich fraction was not toxic or estrogenic to trout hepatocytes, suggesting the concentrations of sulphur acids in this sample were too low to produce any such effects in vitro. Further samples should probably be examined for these compounds. PMID:24252453

  16. Uranium recovery from wet-process phosphoric acid with octylphenyl acid phosphate. Progress report

    SciTech Connect

    Arnold, W.D.; McKamey, D.R.; Baes, C.F.

    1980-01-01

    Studies were continued of a process for recovering uranium from wet-process phosphoric acid with octylphenyl acid phosphate (OPAP), a mixture of mono- and dioctylphenyl phosphoric acids. The mixture contained at least nine impurities, the principal one being octyl phenol, and also material that readily hydrolyzed to octyl phenol and orthophosphoric acid. The combination of mono- and dioctylphenyl phosphoric acids was the principal uranium extractant, but some of the impurities also extracted uranium. Hydrolysis of the extractant had little effect on uranium extraction, as did the presence of moderate concentrations of octyl phenol and trioctylphenyl phosphate. Diluent choice among refined kerosenes, naphthenic mixtures, and paraffinic hydrocarbons also had little effect on uranium extraction, but extraction was much lower when an aromatic diluent was used. Purified OPAP fractions were sparingly soluble in aliphatic hydrocarbon diluents. The solubility was increased by the presence of impurities such as octyl phenol, and by the addition of water or an acidic solution to the extractant-diluent mixture. In continuous stability tests, extractant loss by distribution to the aqueous phase was much less to wet-process phosphoric acid than to reagent grade acid. Uranium recovery from wet-process acid decreased steadily because of the combined effects of extractant poisoning and precipitation of the extractant as a complex with ferric iron. Unaccountable losses of organic phase volume occurred in the continuous tests. While attempts to recover the lost organic phase were unsuccessful, the test results indicate it was not lost by entrainment or dissolution in the phosphoric acid solutions. 21 figures, 8 tables.

  17. Processes to remove acid forming gases from exhaust gases

    DOEpatents

    Chang, Shih-Ger

    1994-01-01

    The present invention relates to a process for reducing the concentration of NO in a gas, which process comprises: (A) contacting a gas sample containing NO with a gaseous oxidizing agent to oxidize the NO to NO.sub.2 ; (B) contacting the gas sample of step (A) comprising NO.sub.2 with an aqueous reagent of bisulfite/sulfite and a compound selected from urea, sulfamic acid, hydrazinium ion, hydrazoic acid, nitroaniline, sulfanilamide, sulfanilic acid, mercaptopropanoic acid, mercaptosuccinic acid, cysteine or combinations thereof at between about 0.degree. and 100.degree. C. at a pH of between about 1 and 7 for between about 0.01 and 60 sec; and (C) optionally contacting the reaction product of step (A) with conventional chemical reagents to reduce the concentrations of the organic products of the reaction in step (B) to environ-mentally acceptable levels. Urea or sulfamic acid are preferred, especially sulfamic acid, and step (C) is not necessary or performed.

  18. Automated cleaning of electronic components

    SciTech Connect

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

    1994-07-01

    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.

  19. Process for clean-burning fuel from low-rank coal

    DOEpatents

    Merriam, Norman W.; Sethi, Vijay; Brecher, Lee E.

    1994-01-01

    A process for upgrading and stabilizing low-rank coal involving the sequential processing of the coal through three fluidized beds; first a dryer, then a pyrolyzer, and finally a cooler. The fluidizing gas for the cooler is the exit gas from the pyrolyzer with the addition of water for cooling. Overhead gas from pyrolyzing is likely burned to furnish the energy for the process. The product coal exits with a tar-like pitch sealant to enhance its safety during storage.

  20. Itaconic acid--a biotechnological process in change.

    PubMed

    Klement, Tobias; Büchs, Jochen

    2013-05-01

    In the last years, itaconic acid has gained increasing interest as future bio-based platform chemical. To replace petrol-based compounds such as methacrylic acid in industry, the economic efficiency of the current biotechnological production processes with the fungus Aspergillus terreus has to be improved. The recent progress in understanding the biosynthesis, the regulation and the cellular transport of itaconic acid has facilitated the optimisation of existing processes as well as the construction of new microbial platforms. However, there is still need for further optimisation to increase the space-time yield, to achieve higher final concentrations and to use a broader range of low cost sustainable raw materials. Genetic engineering and process development need to apply intelligent screening platforms to obtain as much information as possible in small scale. PMID:23298766

  1. Clean process to destroy arsenic-containing organic compounds with recovery of arsenic

    DOEpatents

    Upadhye, R.S.; Wang, F.T.

    1996-08-13

    A reduction method is provided for the treatment of arsenic-containing organic compounds with simultaneous recovery of pure arsenic. Arsenic-containing organic compounds include pesticides, herbicides, and chemical warfare agents such as Lewisite. The arsenic-containing compound is decomposed using a reducing agent. Arsine gas may be formed directly by using a hydrogen-rich reducing agent, or a metal arsenide may be formed using a pure metal reducing agent. In the latter case, the arsenide is reacted with an acid to form arsine gas. In either case, the arsine gas is then reduced to elemental arsenic. 1 fig.

  2. Clean process to destroy arsenic-containing organic compounds with recovery of arsenic

    DOEpatents

    Upadhye, Ravindra S.; Wang, Francis T.

    1996-01-01

    A reduction method is provided for the treatment of arsenic-containing organic compounds with simultaneous recovery of pure arsenic. Arsenic-containing organic compounds include pesticides, herbicides, and chemical warfare agents such as Lewisite. The arsenic-containing compound is decomposed using a reducing agent. Arsine gas may be formed directly by using a hydrogen-rich reducing agent, or a metal arsenide may be formed using a pure metal reducing agent. In the latter case, the arsenide is reacted with an acid to form arsine gas. In either case, the arsine gas is then reduced to elemental arsenic.

  3. Municipal Wastewater Processes. Instructor Guide. Working for Clean Water: An Information Program for Advisory Groups.

    ERIC Educational Resources Information Center

    Stoltzfus, Lorna

    Described is a one-hour overview of the unit processes which comprise a municipal wastewater treatment system. Topics covered in this instructor's guide include types of pollutants encountered, treatment methods, and procedures by which wastewater treatment processes are selected. A slide-tape program is available to supplement this component of…

  4. Investigation into environmentally friendly alternative cleaning processes for hybrid microcircuits to replace vapor degreasing with 1,1,1-trichloroethane. Final report

    SciTech Connect

    Adams, B.E.

    1997-02-01

    Two cleaning processes, one aqueous and one nonaqueous, were investigated as potential replacements for the vapor degreasing process using 1,1,1 trichloroethane (TCA) for hybrid microcircuit assemblies. The aqueous process was based upon saponification chemistry. A 10% solution of either Kester 5768 or Armakleen 2001, heated to 140 F, was sprayed on the hybrid at 450 psig and a flow rate of 5 gpm through a specially designed nozzle which created microdroplets. The nonaqueous process was based upon dissolution chemistry and used d-limonene as the solvent in an immersion and spray process. The d-limonene solvent was followed by an isopropyl alcohol spray rinse to remove the excess d-limonene. The aqueous microdroplet process was found to be successful only for solder reflow profiles that did not exceed 210 C. Furthermore, removal of component marking was a problem and the spray pressure had to be reduced to 130 psig to eliminate damage to capacitor end caps. The d-limonene cleaning was found to be successful for solder reflow temperature up to 250 C when using a four-step cleaning process. The four steps included refluxing the hybrid at 80 C, followed by soaking the hybrid in d-limonene which is heated to 80 C, followed by spray cleaning at 80 psig with room temperature d-limonene, followed by spray cleaning at 80 psig with room temperature IPA was developed to remove residual flux from the hybrid microcircuits. This process was the most robust and most closely matched the cleaning ability of TCA.

  5. A new multiple-stage electrocoagulation process on anaerobic digestion effluent to simultaneously reclaim water and clean up biogas.

    PubMed

    Liu, Zhiguo; Stromberg, David; Liu, Xuming; Liao, Wei; Liu, Yan

    2015-03-21

    A new multiple-stage treatment process was developed via integrating electrocoagulation with biogas pumping to simultaneously reclaim anaerobic digestion effluent and clean up biogas. The 1st stage of electrocoagulation treatment under the preferred reaction condition led to removal efficiencies of 30%, 81%, 37% and >99.9% for total solids, chemical oxygen demand, total nitrogen and total phosphorus, respectively. Raw biogas was then used as a reactant and pumped into the effluent to simultaneously neutralize pH of the effluent and remove H2S in the biogas. The 2nd stage of electrocoagulation treatment on the neutralized effluent showed that under the selected reaction condition, additional 60% and 10% of turbidity and chemical oxygen demand were further removed. The study concluded a dual-purpose approach for the first time to synergistically combine biogas purification and water reclamation for anaerobic digestion system, which well addresses the downstream challenges of anaerobic digestion technology. PMID:25540943

  6. Processes for converting lignocellulosics to reduced acid pyrolysis oil

    SciTech Connect

    Kocal, Joseph Anthony; Brandvold, Timothy A

    2015-01-06

    Processes for producing reduced acid lignocellulosic-derived pyrolysis oil are provided. In a process, lignocellulosic material is fed to a heating zone. A basic solid catalyst is delivered to the heating zone. The lignocellulosic material is pyrolyzed in the presence of the basic solid catalyst in the heating zone to create pyrolysis gases. The oxygen in the pyrolysis gases is catalytically converted to separable species in the heating zone. The pyrolysis gases are removed from the heating zone and are liquefied to form the reduced acid lignocellulosic-derived pyrolysis oil.

  7. Applications of parametric processes to high-quality multicolour ultrashort pulses, pulse cleaning and CEP stable sub-3fs pulse

    NASA Astrophysics Data System (ADS)

    Kobayashi, Takayoshi; Liu, Jun; Okamura, Kotaro

    2012-04-01

    Our recent experimental results of three methods related to and useful for the generation of attosecond pulses are summarized. The pulses obtained by all of them have high qualities in terms of phase, temporal, spectral and spatial properties which are based on the physical principles associated with the parametric processes. First, carrier-envelope phase (CEP) stable sub-5 fs and sub-3 fs pulses by non-collinear optical parametric amplification (NOPA) in the near-infrared and visible spectral range will be described. The mechanism of the passive CEP stabilization is described. Passively stabilized idler and its second harmonic (SH) pulses from NOPAs are compressed to sub-5fs and sub-3fs, respectively. Compression of the idler output from a NOPA and its SH is attained with a specially designed characterization method during the compression. Second, generation of multicolour pulses by the cascaded four-wave mixing process in bulk media is discussed. As short as 15-fs multicoloured femtosecond pulses are obtained with two ˜40 fs pulses incident to a fused-silica glass plate by this method. These broadband multicolour sidebands are expected to provide single-cycle or sub-fs pulses after the Fourier synthesis. Third, a new technique based on self-diffraction in the Kerr medium is used to clean and shorten the femtosecond laser pulse. The cleaned pulse with high temporal contrast is expected to be used as a seed for a background-free petawatt laser system and then used as the laser source for high-energy attosecond pulse generation in a solid target. The mechanisms of CEP stabilization, pulse spectral smoothening and pulse contrast enhancement are comparatively discussed.

  8. Process for clean-burning fuel from low-rank coal

    DOEpatents

    Merriam, N.W.; Sethi, V.; Brecher, L.E.

    1994-06-21

    A process is described for upgrading and stabilizing low-rank coal involving the sequential processing of the coal through three fluidized beds; first a dryer, then a pyrolyzer, and finally a cooler. The fluidizing gas for the cooler is the exit gas from the pyrolyzer with the addition of water for cooling. Overhead gas from pyrolyzing is likely burned to furnish the energy for the process. The product coal exits with a tar-like pitch sealant to enhance its safety during storage. 1 fig.

  9. Minimizing sulfur contamination and rinse water volume required following a sulfuric acid/hydrogen peroxide clean by performing a chemically basic rinse

    SciTech Connect

    Clews, P.J.; Nelson, G.C.; Resnick, P.J.; Matlock, C.A.; Adkins, C.L.J.

    1997-08-01

    Sulfuric acid hydrogen peroxide mixtures (SPM) are commonly used in the semiconductor industry to remove organic contaminants from wafer surfaces. This viscous solution is very difficult to rinse off wafer surfaces. Various rinsing conditions were tested and the resulting residual contamination on the wafer surface was measured. The addition of small amounts of a chemical base such as ammonium hydroxide to the rinse water has been found to be effective in reducing the surface concentration of sulfur and also mitigates the particle growth that occurs on SPM cleaned wafers. The volume of room temperature water required to rinse these wafers is also significantly reduced.

  10. DEMONSTRATION OF ALTERNATIVE CLEANING SYSTEMS

    EPA Science Inventory

    This report focuses on substitute for solvent degreasing processes that eliminate the use of 33/50 chlorinated organic chemicals. The Center for Clean Products and Clean Technologies performed the technical, environmental, and economic evaluation of the solvent degreasing substit...

  11. NATO COMMITTEE ON THE CHALLENGES TO MODERN SOCIETY PILOT STUDY: CLEAN PRODUCTS AND PROCESSES

    EPA Science Inventory

    Promote cooperation for improving the common pollution landscape by stimulating cross-national dialogues and collaboration. Share knowledge on the methods, tools, and technologies for making cleaner products and processes possible.

  12. Emissions involved in acidic deposition processes: Methodology and results

    SciTech Connect

    Placet, M.

    1990-01-01

    Data on the emissions involved in atmospheric acid-base chemistry are crucial to the assessment of acidic deposition and its effects. Sulfur dioxide (SO{sub 2}), nitrogen oxides (NO{sub x}), and volatile organic compounds (VOCs) are the primary chemical compounds involved in acidic deposition processes. In addition, other emission species -- e.g., ammonia, alkaline dust particles, hydrogen chloride, and hydrogen fluoride -- are involved in atmospheric acid-base chemistry, either by contributing acidic constituents or by neutralizing acidic species. Several emissions data bases have been developed under the auspices of the National Acid Precipitation Program (NAPAP). In addition to those developed by NAPAP, emissions data bases and emissions trends estimates also have been developed by organizations such as the Electric Power Research Institute (EPRI) and the U.S. Environmental Protection Agency (EPA). This paper briefly describes and compares the methods used in developing these emissions data bases and presents an overview of their emissions estimates. A more detailed discussion of these topics can be found in the State-of-Science Report on emissions recently released by NAPAP and in the references cited in that report. 14 refs., 4 figs., 1 tab.

  13. THE CHEMICAL AND RADIATION RESISTANCE OF POLYPHENYLENE SULFIDE AS ENCOUNTERED IN THE NUCLEAR WASTE CLEANING PROCESSES

    SciTech Connect

    Fondeur, F.

    2011-10-20

    Polyphenylene sulfide (PPS) is extremely resistant to gamma irradiation, caustic solution, and dilute nitric acid. PPS is the material of construction for the coalescers used in the Modular Caustic-Side Solvent Extraction Unit (MCU). After applying the equivalent of 16 years of gamma irradiation and several months of exposures to caustic solution, no dimensional changes nor chemical changes were detected in PPS whether the PPS was in fiber form or in a composite with E-glass fibers. However, PPS acts as a media for heterogeneous nucleation. In particular, PPS appears to favor aluminosilicate formation in saturated solutions of aluminum and silicon in caustic environments. Parallel testing, in progress, is examining the stability of PPS when exposed to the new solvent formulation under development for MCU. Preliminary data, after two months of exposure, PPS is remarkably stable to the new solvent.

  14. AMERICIUM SEPARATIONS FROM NITRIC ACID PROCESS EFFLUENT STREAMS

    SciTech Connect

    M. BARR; G. JARVINEN; ET AL

    2000-08-01

    The aging of the US nuclear stockpile presents a number of challenges, including the ever-increasing radioactivity of plutonium residues from {sup 241}Am. Minimization of this weak gamma-emitter in process and waste solutions is desirable to reduce both worker exposure and the effects of radiolysis on the final waste product. Removal of americium from plutonium nitric acid processing effluents, however, is complicated by the presence of large.quantities of competing metals, particularly Fe and Al, and-strongly oxidizing acidic solutions. The reprocessing operation offers several points at which americium removal maybe attempted, and we are evaluating two classes of materials targeted at different steps in the process. Extraction chromatography resin materials loaded with three different alkylcarbamoyl phosphinates and phosphine oxides were accessed for Am removal efficiency and Am/Fe selectivity from 1-7 molar nitric acid solutions. Commercial and experimental mono- and bifunctional anion-exchange resins were evaluated for total alpha-activity removal from post-evaporator solutions whose composition, relative to the original nitric acid effluent, is reduced in acid and greatly increased in total salt content. With both classes of materials, americium/total alpha emission removal is sufficient to meet regulatory requirements even under sub-optimal conditions. Batch distribution coefficients, column performance data, and the effects of Fe-masking agents will be presented.

  15. Cleaning agents and asthma.

    PubMed

    Quirce, S; Barranco, P

    2010-01-01

    Although cleaners represent a significant part of the working population worldwide, they remain a relatively understudied occupational group. Epidemiological studies have shown an association between cleaning work and asthma, but the risk factors are uncertain. Cleaning workers are exposed to a large variety of cleaning products containing both irritants and sensitizers, as well as to common indoor allergens and pollutants. Thus, the onset or aggravation of asthma in this group could be related to an irritant-induced mechanism or to specific sensitization. The main sensitizers contained in cleaning products are disinfectants, quaternary ammonium compounds (such as benzalkonium chloride), amine compounds, and fragrances.The strongest airway irritants in cleaning products are bleach (sodium hypochlorite), hydrochloric acid, and alkaline agents (ammonia and sodium hydroxide), which are commonly mixed together. Exposure to the ingredients of cleaning products may give rise to both new-onset asthma, with or without a latency period, and work-exacerbated asthma. High-level exposure to irritants may induce reactive airways dysfunction syndrome. Cleaning workers may also have a greater relative risk of developing asthma due to prolonged low-to-moderate exposure to respiratory irritants. In addition, asthma-like symptoms without confirmed asthma are also common after exposure to cleaning agents. In many cleaners, airway symptoms induced by chemicals and odors cannot be explained by allergic or asthmatic reactions. These patients may have increased sensitivity to inhaled capsaicin, which is known to reflect sensory reactivity, and this condition is termed airway sensory hyperreactivity. PMID:21313993

  16. Laser cleaning -- A new surface cleaning method without pollutions

    SciTech Connect

    Lu, Y.F.; Aoyagi, Y.

    1994-12-31

    Surface contaminations are removed by laser irradiation with pulse output and short wavelength from various substrate such as magnetic head slide, glass and metals. Laser cleaning is a new dry process to remove surface organic contaminations without using ultrasonic cleaning in organic solvents. This provides a new dry process to clean different substrate surfaces and can take the place of conventional wet cleaning processes such as ultrasonic cleaning with CFC and other organic solvents. The mechanisms of laser cleaning may include laser photodecomposition, laser ablation and surface vibration due to the impact of laser pulse. It is found that short wavelength and short pulse duration are necessary for effective cleaning. It is also found that an appropriate energy density is critical to achieve effective cleaning without causing surface oxidation and secondary contamination.

  17. Separation processes for recovering alloy steels from grinding sludge: Supercritical carbon dioxide extraction and aqueous cleaning

    SciTech Connect

    Fu, H.; Matthews, M.A.

    1999-04-01

    Two separation processes have been developed to remove contaminants (cutting oil with trace phosphorus additive) from high-speed steel grinding sludge. One process uses an aqueous surfactant washing technique, and the second process uses supercritical carbon dioxide (SCCO{sub 2}) extraction. Bench-scale aqueous washings have shown that the required phosphorus removal is easily obtained, but a sufficient oil removal is more difficult. The experimental results also indicate a strong dependence of the aqueous washing efficiency on the choice of a suitable surfactant. A mass transfer model is used to simulate a semi-continuous washing process. SCCO{sub 2} extraction at 80 C and 340 atm shows that approximately 80% of the oil can be removed from the sludge during a 60-minute process to produce a batch of recyclable steel, and that the phosphorus removal also reaches the required level. A linear desorption model is used to describe the irreversible desorption of oil from the solid phase into the CO{sub 2} phase, and the simulated results agree very well with the experimental data.

  18. Effects of ultrasonic fields in the phosphoric acid process

    NASA Technical Reports Server (NTRS)

    Kowalska, E.; Mizera, J.; Jakobiec, H.

    1974-01-01

    A process of apatite decomposition with sulfuric acid was studied under the influence of ultrasound in the phosphoric acid production process. The studies were carried out with and without ultrasonic fields in the reaction mixture, which resembled the mixing ratio used in technical production processes. Ultrasound with a frequency of 20 kHz and an intensity of 1 W/sq cm was used in the studies. A very favorable ultrasonic effect upon the degree of apatite decomposition was observed. The ultrasonic field affects the shape of byproduct gypsum crystals. In the H3PO4 production process without ultrasound, the byproduct gypsum crystallizes as long, thin needles which cause problems in filtration. In the trials involving the application of wound, gypsum crystallized in the form of small platelets possessing a favorable ratio of length to width.

  19. OXALATE MASS BALANCE DURING CHEMICAL CLEANING IN TANK 6F

    SciTech Connect

    Poirier, M.; Fink, S.

    2011-07-22

    The Savannah River Remediation (SRR) is preparing Tank 6F for closure. The first step in preparing the tank for closure is mechanical sludge removal. Following mechanical sludge removal, SRS performed chemical cleaning with oxalic acid to remove the sludge heel. Personnel are currently assessing the effectiveness of the chemical cleaning to determine whether the tank is ready for closure. SRR personnel collected liquid samples during chemical cleaning and submitted them to Savannah River National Laboratory (SRNL) for analysis. Following chemical cleaning, they collected a solid sample (also known as 'process sample') and submitted it to SRNL for analysis. The authors analyzed these samples to assess the effectiveness of the chemical cleaning process. Analysis of the anions showed the measured oxalate removed from Tank 6F to be approximately 50% of the amount added in the oxalic acid. To close the oxalate mass balance, the author collected solid samples, leached them with nitric acid, and measured the concentration of cations and anions in the leachate. Some conclusions from this work are: (1) Approximately 65% of the oxalate added as oxalic acid was removed with the decanted liquid. (2) Approximately 1% of the oxalate (added to the tank as oxalic acid) formed precipitates with compounds such as nickel, manganese, sodium, and iron (II), and was dissolved with nitric acid. (3) As much as 30% of the oxalate may have decomposed forming carbon dioxide. The balance does not fully account for all the oxalate added. The offset represents the combined uncertainty in the analyses and sampling.

  20. New process makes production of highly acid gas economical

    SciTech Connect

    Gazzi, L.; Cotone, G.; Rescalli, C.; Soldati, G.F.; Vetere, A.

    1982-08-01

    Development of cryogenic processing combined with a new solvent for removing H/sub 2/S and CO/sub 2/ from natural gas has significantly reduced the costs for plant equipment and the energy needed to run it. This results in much lower treatment costs per Mcf and makes natural gas containing as much as 80% acid gas profitable to produce.

  1. Modeling of matrix acidizing process under reservoir conditions

    NASA Astrophysics Data System (ADS)

    Turegeldieva, Karlygash; Assilbekov, Bakhytzhan; Zhapbasbayev, Uzak; Zolotukhin, Anatoly; Bekibaev, Timur; Kenzhebekov, Nurlan; Gubkin Russian State University of oil; gas Collaboration

    2013-11-01

    Effectiveness of the process depends on the parameters: well choice, geological structure of the reservoir, definition of physical and chemical properties of rocks and fluids, agent choice. There are different mathematical models of the matrix acidizing, including the two scale model. These models describe the process in the core scale and Darcy scale, i.e. in an area with dimensions of several centimeters. It leads to the main problem - how to use these models to the near wellbore scale under reservoir conditions. Some authors have increased the dimensions of the cores in numerical simulations and investigated the influence of the core dimensions to acidizing process. In this paper effort to indirectly solve this problem made. It based on boundary conditions alteration and simultaneous solution of matrix acidizing in damaged zone and reservoir fluid flow models. Furthermore in this work the criterion of the acid injection shut down for optimal breakthrough volume calculation was modified. Influence of boundary conditions on near well-bore zone treatment process was investigated. Science Committee of Ministry of Education and Science of Republic of Kazakhstan.

  2. Method for cleaning and passivating a metal surface

    NASA Technical Reports Server (NTRS)

    Alexander, George B. (Inventor); Carpenter, Norman F. (Inventor)

    1976-01-01

    A cleaning solvent useful in the cleaning of metal surfaces, e.g. nickle-iron alloys, contains sulfamic acid, citric acid, a solvent for hydrocarbon residues, and a surfactant. Metal surfaces are cleaned by contacting the surface with the cleaning solvent and then passivated by contact with aqueous solutions of citric acid or sodium nitrite or a combination of the two.

  3. Charge generation associated with liquid spraying in tank cleaning and comparable processes - preliminary experiments

    NASA Astrophysics Data System (ADS)

    Blum, Carsten; Losert, Oswald F. J.

    2015-10-01

    The BG RCI has initiated investigations in order to improve the data basis for assessing the ignition hazard by electrostatic charging processes associated with the spraying of liquids. On the base of preliminary experiments, we established procedures for measurements of electric field strength and charging current in the presence of aerosol particles. Results obtained with three different nozzle types, variation of pressure and with built-in deflecting plate are presented.

  4. Understanding Particle Defect Transport in an Ultra-Clean Sputter Coating Process

    SciTech Connect

    Walton, C; Kearney, P; Folta, J; Sweeney, D; Mirkarimi, P

    2003-03-24

    Low-defect mask blanks remain a key technical challenge to Extreme Ultraviolet Lithography (EUVL). The mask blank is ion-beam sputter-coated with an 81-layer Mo/Si multilayer stack for high reflectance at {lambda} = 13.4nm. The current mask coating process can achieve a median added defect level of 0.05 defects/cm{sup 2} (12 added defects 90nm or larger on a 200mm Si-wafer test substrate), but this must be reduced by about a factor of 10 to meet mask cost requirements for EUVL. To further reduce the particle defect level, we have studied pathways for particle transport, using test particles and particles native to the coating process, and combined the results into a computational model of particle transport in an ion-beam sputter system. At process pressure, gas drag is negligible for particles above 100nm, so particles travel ballistically until they hit a surface. Bounce from chamber walls allows particles to reach all surfaces in the chamber if they have initial velocities above {approx}100m/s. The ion beam has sufficient momentum to entrain slower particles and accelerate them toward the sputter target, where some can bounce to the substrate. The model shows preliminary agreement with experimental defect distributions on witness wafers at various positions within the coating chamber.

  5. THE CLEANING OF 303 STAINLESS STEEL

    SciTech Connect

    Shen, T H

    2004-04-20

    The sulfur found on the surfaces of stainless steel 303 (SS303) after nitric acid passivation originated from the MnS inclusions in the steel. The nitric acid attacked and dissolved these MnS inclusions, and redeposited micron-sized elemental sulfur particles back to the surface. To develop an alternative passivation procedure for SS303, citric and phosphoric acids have been evaluated. The experimental results show neither acid causes a significant amount of sulfur deposit. Thus, these two acids can be used as alternatives to nitric acid passivation for NIF applications. For SS303 previously passivated by nitric acid, NaOH soak can be used as a remedial cleaning process to effectively remove the sulfur deposits.

  6. Biological sulfuric acid transformation: Reactor design and process optimization.

    PubMed

    Stucki, G; Hanselmann, K W; Hürzeler, R A

    1993-02-01

    As an alternative to the current disposal technologies for waste sulfuric acid, a new combination of recycling processes was developed. The strong acid (H(2)SO(4)) is biologically converted with the weak acid (CH(3)COOH) into two volatile weak acids (H(2)S, H(2)CO(3)) by sulfate-reducing bacteria. The transformation is possible without prior neutralization of the sulfuric acid. The microbially mediated transformation can be followed by physiochemical processes for the further conversion of the H(2)S.The reduction of sulfate to H(2)S is carried out under carbon-limited conditions at pH 7.5 to 8.5. A fixed-bed biofilm column reactor is used in conjunction with a separate gas-stripping column which was installed in the recycle stream. Sulfate, total sulfide, and the carbon substrate (in most cases acetate) were determined quantitatively. H(2)S and CO(2) are continually removed by stripping with N(2). Optimal removal is achieved under pH conditions which are adjusted to values below the pK(a)-values of the acids. The H(2)S concentration in the stripped gas was 2% to 8% (v/v) if H(2)SO(4) and CH(3)COOH are fed to the recycle stream just before the stripping column.Microbiol conversion rates of 65 g of sulfate reduced per liter of bioreactor volume per day are achieved and bacterial conversion efficiencies for sulfate of more than 95% can be maintained if the concentration of undissociated H(2)S is kept below 40 to 50 mg/L. Porous glass spheres, lava beads, and polyurethane pellets are useful matrices for the attachment of the bacterial biomass. Theoretical aspects and the dependence of the overall conversion performance on selected process parameters are illustrated in the Appendix to this article. PMID:18609554

  7. Test rig and particulate deposit and cleaning evaluation processes using the same

    DOEpatents

    Schroder, Mark Stewart; Woodmansee, Donald Ernest; Beadie, Douglas Frank

    2002-01-01

    A rig and test program for determining the amount, if any, of contamination that will collect in the passages of a fluid flow system, such as a power plant fluid delivery system to equipment assemblies or sub-assemblies, and for establishing methods and processes for removing contamination therefrom. In the presently proposed embodiment, the rig and test programs are adapted in particular to utilize a high-pressure, high-volume water flush to remove contamination from substantially the entire fluid delivery system, both the quantity of contamination and as disposed or deposited within the system.

  8. Cryogenic process for removing acidic gases from gas mixtures

    SciTech Connect

    Gazzi, L.; Cotone, G.; Ginnasi, A.; Rescalli, C.; Soldati, G.; Vetere, A.

    1985-04-30

    Low temperature treatments are combined with solvent treatments using particularly selective solvents for stripping acidic gases such as carbon dioxide and hydrogen sulphide from natural gas or from synthetic gases. The preferred solvents are a wide range of compounds having an esteric or an etheric function in their molecule, but there are also examples of compounds which have the two functions simultaneously. The stripping process is comparatively simple, is efficient, especially for high contents of acidic gases in the raw gas streams, and is economically acceptable.

  9. Clean combined-cycle SOFC power plant — cell modelling and process analysis

    NASA Astrophysics Data System (ADS)

    Riensche, E.; Achenbach, E.; Froning, D.; Haines, M. R.; Heidug, W. K.; Lokurlu, A.; von Andrian, S.

    The design principle of a specially adapted solid-oxide fuel cell power plant for the production of electricity from hydrocarbons without the emission of greenhouse gases is described. To achieve CO 2 separation in the exhaust stream, it is necessary to burn the unused fuel without directly mixing it with air, which would introduce nitrogen. Therefore, the spent fuel is passed over a bank of oxygen ion conducting tubes very similar in configuration to the electrochemical tubes in the main stack of the fuel cell. In such an SOFC system, pure CO 2 is produced without the need for a special CO 2 separation process. After liquefaction, CO 2 can be re-injected into an underground reservoir. A plant simulation model consists of four main parts, that is, turbo-expansion of natural gas, fuel cell stack, periphery of the stack, and CO 2 recompression. A tubular SOFC concept is preferred. The spent fuel leaving the cell tube bundle is burned with pure oxygen instead of air. The oxygen is separated from the air in an additional small tube bundle of oxygen separation tubes. In this process, mixing of CO 2 and N 2 is avoided, so that liquefaction of CO 2 becomes feasible. As a design tool, a computer model for tubular cells with an air feed tube has been developed based on an existing planar model. Plant simulation indicates the main contributors to power production (tubular SOFC, exhaust air expander) and power consumption (air compressor, oxygen separation).

  10. System and process for capture of acid gasses at elevated pressure from gaseous process streams

    DOEpatents

    Heldebrant, David J.; Koech, Phillip K.; Linehan, John C.; Rainbolt, James E.; Bearden, Mark D.; Zheng, Feng

    2016-09-06

    A system, method, and material that enables the pressure-activated reversible chemical capture of acid gasses such as CO.sub.2 from gas volumes such as streams, flows or any other volume. Once the acid gas is chemically captured, the resulting product typically a zwitterionic salt, can be subjected to a reduced pressure whereupon the resulting product will release the captures acid gas and the capture material will be regenerated. The invention includes this process as well as the materials and systems for carrying out and enabling this process.

  11. Enhanced Chemical Cleaning

    SciTech Connect

    Spires, Renee H.

    2010-11-01

    Renee Spires, Project Manager at Savannah River Remediation, opens Session 3 (Accelerated Waste Retrieval and Closure: Key Technologies) at the 2010 EM Waste Processing Technical Exchange with a talk on enhanced chemical cleaning.

  12. ALTERNATIVE AND ENHANCED CHEMICAL CLEANING: CORROSION STUDIES RESULTS: FY2010

    SciTech Connect

    Wiersma, B.

    2010-09-29

    Due to the need to close High Level Waste storage tanks, chemical cleaning methods are needed for the removal of sludge heel materials remaining at the completion of mechanical tank cleaning efforts. Oxalic acid is considered the preferred cleaning reagent for heel dissolution of iron-based sludge. However, the large quantity of chemical reagents added to the tank farm from oxalic acid based cleaning has significant downstream impacts. Optimization of the oxalic acid cleaning process can potentially reduce the downstream impacts from chemical cleaning. To optimize oxalic acid usage, a detailed understanding of the chemistry of oxalic acid based sludge dissolution is required. Additionally, other acidic systems may be required for specific waste components that have low solubility in oxalic acid, and as a means to reduce oxalic acid usage in general. Electrochemical corrosion studies were conducted with 1 wt. % oxalic acid at mineral acid concentrations above and below the optimal conditions for this oxalic acid concentration. Testing environments included pure reagents, pure iron and aluminum phases, and sludge simulants. Mineral acid concentrations greater than 0.2 M and temperatures greater than 50 C result in unacceptably high corrosion rates. Results showed that manageable corrosion rates of carbon steel can be achieved at dilute mineral acid concentrations (i.e. less than 0.2 M) and low temperatures based on the contact times involved. Therefore, it is recommended that future dissolution and corrosion testing be performed with a dilute mineral acid and a less concentrated oxalic acid (e.g., 0.5 wt.%) that still promotes optimal dissolution. This recommendation requires the processing of greater water volumes than those for the baseline process during heel dissolution, but allows for minimization of oxalic acid additions. The following conclusions can be drawn from the test results: (1) In both nitric and sulfuric acid based reagents, the low temperature and

  13. Cleaning of Free Machining Brass

    SciTech Connect

    Shen, T

    2005-12-29

    We have investigated four brightening treatments proposed by two cleaning vendors for cleaning free machining brass. The experimental results showed that none of the proposed brightening treatments passed the swipe test. Thus, we maintain the recommendation of not using the brightening process in the cleaning of free machining brass for NIF application.

  14. Green process for chemical functionalization of nanocellulose with carboxylic acids.

    PubMed

    Espino-Pérez, Etzael; Domenek, Sandra; Belgacem, Naceur; Sillard, Cécile; Bras, Julien

    2014-12-01

    An environmentally friendly and simple method, named SolReact, has been developed for a solvent-free esterification of cellulose nanocrystals (CNC) surface by using two nontoxic carboxylic acids (CA), phenylacetic acid and hydrocinnamic acid. In this process, the carboxylic acids do not only act as grafting agent, but also as solvent media above their melting point. Key is the in situ solvent exchange by water evaporation driving the esterification reaction without drying the CNC. Atomic force microscopy and X-ray diffraction analyses showed no significant change in the CNC dimensions and crystallinity index after this green process. The presence of the grafted carboxylic was characterized by analysis of the "bulk" CNC with elemental analysis, infrared spectroscopy, and (13)C NMR. The ability to tune the surface properties of grafted nanocrystals (CNC-g-CA) was evaluated by X-ray photoelectron spectroscopy analysis. The hydrophobicity behavior of the functionalized CNC was studied through the water contact-angle measurements and vapor adsorption. The functionalization of these bionanoparticles may offer applications in composite manufacturing, where these nanoparticles have limited dispersibility in hydrophobic polymer matrices and as nanoadsorbers due to the presence of phenolic groups attached on the surface. PMID:25353612

  15. Clean coal

    SciTech Connect

    Liang-Shih Fan; Fanxing Li

    2006-07-15

    The article describes the physics-based techniques that are helping in clean coal conversion processes. The major challenge is to find a cost- effective way to remove carbon dioxide from the flue gas of power plants. One industrially proven method is to dissolve CO{sub 2} in the solvent monoethanolamine (MEA) at a temperature of 38{sup o}C and then release it from the solvent in another unit when heated to 150{sup o}C. This produces CO{sub 2} ready for sequestration. Research is in progress with alternative solvents that require less energy. Another technique is to use enriched oxygen in place of air in the combustion process which produces CO{sub 2} ready for sequestration. A process that is more attractive from an energy management viewpoint is to gasify coal so that it is partially oxidized, producing a fuel while consuming significantly less oxygen. Several IGCC schemes are in operation which produce syngas for use as a feedstock, in addition to electricity and hydrogen. These schemes are costly as they require an air separation unit. Novel approaches to coal gasification based on 'membrane separation' or chemical looping could reduce the costs significantly while effectively capturing carbon dioxide. 1 ref., 2 figs., 1 photo.

  16. Microbial communities, processes and functions in acid mine drainage ecosystems.

    PubMed

    Chen, Lin-Xing; Huang, Li-Nan; Méndez-García, Celia; Kuang, Jia-Liang; Hua, Zheng-Shuang; Liu, Jun; Shu, Wen-Sheng

    2016-04-01

    Acid mine drainage (AMD) is generated from the oxidative dissolution of metal sulfides when water and oxygen are available largely due to human mining activities. This process can be accelerated by indigenous microorganisms. In the last several decades, culture-dependent researches have uncovered and validated the roles of AMD microorganisms in metal sulfides oxidation and acid generation processes, and culture-independent studies have largely revealed the diversity and metabolic potentials and activities of AMD communities, leading towards a full understanding of the microbial diversity, functions and interactions in AMD ecosystems. This review describes the diversity of microorganisms and their functions in AMD ecosystems, and discusses their biotechnological applications in biomining and AMD bioremediation according to their capabilities. PMID:26921733

  17. A Development of Ceramics Cylinder Type Sulfuric Acid Decomposer for Thermo-Chemical Iodine-Sulfur Process Pilot Plant

    SciTech Connect

    Hiroshi Fukui; Isao Minatsuki; Kazuo Ishino

    2006-07-01

    The hydrogen production method applying thermo-chemical Iodine-Sulfur process (IS process) which uses a nuclear high temperature gas cooled reactor is world widely greatly concerned from the view point of a combination as a clean method, free carbon dioxide in essence. In this process, it is essential a using ceramic material, especially SiC because a operation condition of this process is very corrosive due to a sulfuric acid atmosphere with high temperature and high pressure. In the IS process, a sulfuric acid decomposer is the key component which performs evaporating of sulfuric acid from liquid to gas and disassembling to SO{sub 2} gas. SiC was selected as ceramic material to apply for the sulfuric acid decomposer and a new type of binding material was also developed for SiC junction. This technology is expected to wide application not only for a sulfuric acid decomposer but also for various type components in this process. Process parameters were provided as design condition for the decomposer. The configuration of the sulfuric acid decomposer was studied, and a cylindrical tubes assembling type was selected. The advantage of this type is applicable for various type of components in the IS process due to manufacturing with using only simple shape part. A sulfuric acid decomposer was divided into two regions of the liquid and the gaseous phase of sulfuric acid. The thermal structural integrity analysis was studied for the liquid phase part. From the result of this analysis, it was investigated that the stress was below the strength of the breakdown probability 1/100,000 at any position, base material or junction part. The prototype model was manufactured, which was a ceramic portion in the liquid phase part, comparatively complicated configuration, of a sulfuric acid decomposer. The size of model was about 1.9 m in height, 1.0 m in width. Thirty-six cylinders including inlet and outlet nozzles were combined and each part article was joined using the new binder

  18. A Development of Ceramics Cylinder Type Sulfuric Acid Decomposer for Thermo-Chemical Iodine-Sulfur Process Pilot Plant

    NASA Astrophysics Data System (ADS)

    Minatsuki, Isao; Fukui, Hiroshi; Ishino, Kazuo

    The hydrogen production method applying thermo-chemical Iodine-Sulfur process (IS process) which uses a nuclear high temperature gas cooled reactor is world widely greatly concerned from the view point of a combination as a clean method, free carbon dioxide in essence. In this process, it is essential a using ceramic material, especially SiC because a operation condition of this process is very corrosive due to a sulfuric acid atmosphere with high temperature and high pressure. In the IS process, a sulfuric acid decomposer is the key component which performs evaporating of sulfuric acid from liquid to gas and disassembling to SO2 gas. SiC was selected as ceramic material to apply for the sulfuric acid decomposer and a new type of binding material was also developed for SiC junction. This technology is expected to wide application not only for a sulfuric acid decomposer but also for various type components in this process. Process parameters were provided as design condition for the decomposer. The configuration of the sulfuric acid decomposer was studied, and a cylindrical tubes assembling type was selected. The advantage of this type is applicable for various type of components in the IS process due to manufacturing with using only simple shape part. A sulfuric acid decomposer was divided into two regions of the liquid and the gaseous phase of sulfuric acid. The thermal structural integrity analysis was studied for the liquid phase part. From the result of this analysis, it was investigated that the stress was below the strength of the breakdown probability 1/100,000 at any position, base material or junction part. The prototype model was manufactured, which was a ceramic portion in the liquid phase part, comparatively complicated configuration, of a sulfuric acid decomposer. The size of model was about 1.9m in height, 1.0m in width. Thirty-six cylinders including inlet and outlet nozzles were combined and each part article was joined using the new binder (slurry

  19. Electron-beam-induced deposition and post-treatment processes to locally generate clean titanium oxide nanostructures on Si(100).

    PubMed

    Schirmer, M; Walz, M-M; Vollnhals, F; Lukasczyk, T; Sandmann, A; Chen, C; Steinrück, H-P; Marbach, H

    2011-02-25

    We have investigated the lithographic generation of TiO(x) nanostructures on Si(100) via electron-beam-induced deposition (EBID) of titanium tetraisopropoxide (TTIP) in ultra-high vacuum (UHV) by scanning electron microscopy (SEM) and local Auger electron spectroscopy (AES). In addition, the fabricated nanostructures were also characterized ex situ via atomic force microscopy (AFM) under ambient conditions. In EBID, a highly focused electron beam is used to locally decompose precursor molecules and thereby to generate a deposit. A drawback of this nanofabrication technique is the unintended deposition of material in the vicinity of the impact position of the primary electron beam due to so-called proximity effects. Herein, we present a post-treatment procedure to deplete the unintended deposits by moderate sputtering after the deposition process. Moreover, we were able to observe the formation of pure titanium oxide nanocrystals (<100 nm) in situ upon heating the sample in a well-defined oxygen atmosphere. While the nanocrystal growth for the as-deposited structures also occurs in the surroundings of the irradiated area due to proximity effects, it is limited to the pre-defined regions, if the sample was sputtered before heating the sample under oxygen atmosphere. The described two-step post-treatment procedure after EBID presents a new pathway for the fabrication of clean localized nanostructures. PMID:21242619

  20. Electron-beam-induced deposition and post-treatment processes to locally generate clean titanium oxide nanostructures on Si(100)

    NASA Astrophysics Data System (ADS)

    Schirmer, M.; Walz, M.-M.; Vollnhals, F.; Lukasczyk, T.; Sandmann, A.; Chen, C.; Steinrück, H.-P.; Marbach, H.

    2011-02-01

    We have investigated the lithographic generation of TiOx nanostructures on Si(100) via electron-beam-induced deposition (EBID) of titanium tetraisopropoxide (TTIP) in ultra-high vacuum (UHV) by scanning electron microscopy (SEM) and local Auger electron spectroscopy (AES). In addition, the fabricated nanostructures were also characterized ex situ via atomic force microscopy (AFM) under ambient conditions. In EBID, a highly focused electron beam is used to locally decompose precursor molecules and thereby to generate a deposit. A drawback of this nanofabrication technique is the unintended deposition of material in the vicinity of the impact position of the primary electron beam due to so-called proximity effects. Herein, we present a post-treatment procedure to deplete the unintended deposits by moderate sputtering after the deposition process. Moreover, we were able to observe the formation of pure titanium oxide nanocrystals (<100 nm) in situ upon heating the sample in a well-defined oxygen atmosphere. While the nanocrystal growth for the as-deposited structures also occurs in the surroundings of the irradiated area due to proximity effects, it is limited to the pre-defined regions, if the sample was sputtered before heating the sample under oxygen atmosphere. The described two-step post-treatment procedure after EBID presents a new pathway for the fabrication of clean localized nanostructures.

  1. Development of OTM Syngas Process and Testing of Syngas Derived Ultra-clean Fuels in Diesel Engines and Fuel Cells

    SciTech Connect

    E.T. Robinson; James P. Meagher; Prasad Apte; Xingun Gui; Tytus R. Bulicz; Siv Aasland; Charles Besecker; Jack Chen Bart A. van Hassel; Olga Polevaya; Rafey Khan; Piyush Pilaniwalla

    2002-12-31

    This topical report summarizes work accomplished for the Program from November 1, 2001 to December 31, 2002 in the following task areas: Task 1: Materials Development; Task 2: Composite Development; Task 4: Reactor Design and Process Optimization; Task 8: Fuels and Engine Testing; 8.1 International Diesel Engine Program; 8.2 Nuvera Fuel Cell Program; and Task 10: Program Management. Major progress has been made towards developing high temperature, high performance, robust, oxygen transport elements. In addition, a novel reactor design has been proposed that co-produces hydrogen, lowers cost and improves system operability. Fuel and engine testing is progressing well, but was delayed somewhat due to the hiatus in program funding in 2002. The Nuvera fuel cell portion of the program was completed on schedule and delivered promising results regarding low emission fuels for transportation fuel cells. The evaluation of ultra-clean diesel fuels continues in single cylinder (SCTE) and multiple cylinder (MCTE) test rigs at International Truck and Engine. FT diesel and a BP oxygenate showed significant emissions reductions in comparison to baseline petroleum diesel fuels. Overall through the end of 2002 the program remains under budget, but behind schedule in some areas.

  2. Anti-reflection coatings applied by acid leaching process

    NASA Technical Reports Server (NTRS)

    Pastirik, E.

    1980-01-01

    The Magicote C process developed by S.M. Thompsen was evaluated for use in applying an antireflective coating to the cover plates of solar panels. The process uses a fluosilicic acid solution supersaturated with silica at elevated temperature to selectively attack the surface of soda-lime glass cover plates and alter the physical and chemical composition of a thin layer of glass. The altered glass layer constitutes an antireflective coating. The process produces coatings of excellent optical quality which possess outstanding resistance to soiling and staining. The coatings produced are not resistant to mechanical abrasion and are attacked to some extent by glass cleansers. Control of the filming process was found to be difficult.

  3. Anti-reflection coatings applied by acid leaching process

    NASA Astrophysics Data System (ADS)

    Pastirik, E.

    1980-09-01

    The Magicote C process developed by S.M. Thompsen was evaluated for use in applying an antireflective coating to the cover plates of solar panels. The process uses a fluosilicic acid solution supersaturated with silica at elevated temperature to selectively attack the surface of soda-lime glass cover plates and alter the physical and chemical composition of a thin layer of glass. The altered glass layer constitutes an antireflective coating. The process produces coatings of excellent optical quality which possess outstanding resistance to soiling and staining. The coatings produced are not resistant to mechanical abrasion and are attacked to some extent by glass cleansers. Control of the filming process was found to be difficult.

  4. 21 CFR 173.280 - Solvent extraction process for citric acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Solvent extraction process for citric acid. 173... Solvent extraction process for citric acid. A solvent extraction process for recovery of citric acid from conventional Aspergillus niger fermentation liquor may be safely used to produce food-grade citric acid...

  5. 21 CFR 173.280 - Solvent extraction process for citric acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Solvent extraction process for citric acid. 173... Solvent extraction process for citric acid. A solvent extraction process for recovery of citric acid from conventional Aspergillus niger fermentation liquor may be safely used to produce food-grade citric acid...

  6. Analysis of the Clean Air Act Amendments of 1990: A forecast of the electric utility industry response to Title IV, Acid Deposition Control

    SciTech Connect

    Molburg, J.C.; Fox, J.A.; Pandola, G.; Cilek, C.M.

    1991-10-01

    The Clean Air Act Amendments of 1990 incorporate, for the first time, provisions aimed specifically at the control of acid rain. These provisions restrict emissions of sulfur dioxide (SO{sub 2}) and oxides of nitrogen (NO{sub x}) from electric power generating stations. The restrictions on SO{sub 2} take the form of an overall cap on the aggregate emissions from major generating plants, allowing substantial flexibility in the industry`s response to those restrictions. This report discusses one response scenario through the year 2030 that was examined through a simulation of the utility industry based on assumptions consistent with characterizations used in the National Energy Strategy reference case. It also makes projections of emissions that would result from the use of existing and new capacity and of the associated additional costs of meeting demand subject to the emission limitations imposed by the Clean Air Act. Fuel-use effects, including coal-market shifts, consistent with the response scenario are also described. These results, while dependent on specific assumptions for this scenario, provide insight into the general character of the likely utility industry response to Title IV.

  7. Analysis of the Clean Air Act Amendments of 1990: A forecast of the electric utility industry response to Title IV, Acid Deposition Control

    SciTech Connect

    Molburg, J.C.; Fox, J.A.; Pandola, G.; Cilek, C.M.

    1991-10-01

    The Clean Air Act Amendments of 1990 incorporate, for the first time, provisions aimed specifically at the control of acid rain. These provisions restrict emissions of sulfur dioxide (SO[sub 2]) and oxides of nitrogen (NO[sub x]) from electric power generating stations. The restrictions on SO[sub 2] take the form of an overall cap on the aggregate emissions from major generating plants, allowing substantial flexibility in the industry's response to those restrictions. This report discusses one response scenario through the year 2030 that was examined through a simulation of the utility industry based on assumptions consistent with characterizations used in the National Energy Strategy reference case. It also makes projections of emissions that would result from the use of existing and new capacity and of the associated additional costs of meeting demand subject to the emission limitations imposed by the Clean Air Act. Fuel-use effects, including coal-market shifts, consistent with the response scenario are also described. These results, while dependent on specific assumptions for this scenario, provide insight into the general character of the likely utility industry response to Title IV.

  8. Kinetic study of formic acid degradation by Fe3+ doped TiO2 self-cleaning nanostructure surfaces prepared by cold spray

    NASA Astrophysics Data System (ADS)

    Sayyar, Zahra; Akbar Babaluo, Ali; Shahrouzi, Javad Rahbar

    2015-04-01

    A self-cleaning solution was introduced in this paper based on sol-gel and was applied for preparing self-cleaning TiO2. Fe3+ ions have been doped into the TiO2 crystal lattice. XRD analysis indicated that the obtained TiO2 powder contains mainly the anatase phase and TiO2 powder has a crystallite size distribution of 10-12 nm. SEM micrographs have also confirmed nanometric distribution of the obtained powder. A series of uniform and transparent TiO2 and Fe/TiO2 films were prepared by cold spray technique which may result in high uniformity in the final coated surfaces. Photocatalytic activity of the thin films was investigated through degradation of aqueous formic acid under UV-visible light. The Langmuir-Hinshelwood kinetic model was used to interpret quantitatively the observed kinetic experimental result. Comparative study of the obtained coated surfaces with those of uncoated surfaces, demonstrated a remarkable performance. The Fe/TiO2 films and their calcination at 650 °C demonstrated the highest photocatalytic activity.

  9. Major hydrogeochemical processes in an acid mine drainage affected estuary.

    PubMed

    Asta, Maria P; Calleja, Maria Ll; Pérez-López, Rafael; Auqué, Luis F

    2015-02-15

    This study provides geochemical data with the aim of identifying and quantifying the main processes occurring in an Acid Mine Drainage (AMD) affected estuary. With that purpose, water samples of the Huelva estuary were collected during a tidal half-cycle and ion-ion plots and geochemical modeling were performed to obtain a general conceptual model. Modeling results indicated that the main processes responsible for the hydrochemical evolution of the waters are: (i) the mixing of acid fluvial water with alkaline ocean water; (ii) precipitation of Fe oxyhydroxysulfates (schwertmannite) and hydroxides (ferrihydrite); (iii) precipitation of Al hydroxysulfates (jurbanite) and hydroxides (amorphous Al(OH)3); (iv) dissolution of calcite; and (v) dissolution of gypsum. All these processes, thermodynamically feasible in the light of their calculated saturation states, were quantified by mass-balance calculations and validated by reaction-path calculations. In addition, sorption processes were deduced by the non-conservative behavior of some elements (e.g., Cu and Zn). PMID:25530015

  10. Trends in visibility, PM{sub 2.5}, and deposition expected from the Acid Rain Provisions of the 1990 Clean Air Act Amendments

    SciTech Connect

    Shannon, J.D.; Hanson, D.A.

    1997-08-01

    The Acid Rain Provisions (Title IV) of the 1990 Clean Air Act Amendments (CAAA) are designed to reduce the deposition of SO{sub 2} and sulfate and, to a lesser extent, the deposition of NO{sub x} and nitrate through reduction of SO{sub 2} and NO{sub x} emissions. However, other important benefits are anticipated from the emission control strategies, including improvement of regional visibility and reductions in concentrations of fine particles (PM2.5). In this study, the authors coupled utility emissions forecasts with the Advanced Statistical Trajectory Regional Air Pollution (ASTRAP) model and the Visibility Assessment Scoping Model (VASM) to calculate and compare the relative improvements by 2010 in visual impairment, PM2.5 concentrations, and sulfate wet deposition at selected sites in the eastern United States.

  11. Value of furfural/ethanol coproduction from acid hydrolysis processes

    SciTech Connect

    Parker, S.; Calnon, M.; Feinberg, D.; Power, A.; Weiss, L.

    1983-08-01

    The benefits of two modifications in the acid hydrolysis of cellulosic feedstocks for the production of ethanol fuels were investigated: marketing of the by-product furfural and xylose fermentation. Preliminary analysis indicate that the furfural by-product furfural and xylose fermentation. Perliminary analyses indicate that the furfural by-product credit is more beneficial at a minimum net profit of $0.08/lb of furfural. For this credit to have a major impact on ethanol production costs, new markets for large quantities of furfural must be identified. Furfural can be an alternative feedstock for hydrocarbon-based commodity chemicals. The costs and profitabilities of producing five chemicals from furfurals as opposed to conventional hydrocarbon-based feedstocks were studied. The furfural processes for production of styrene and butadiene were found to be marginally competitive or not competitive. The furfural processes for adipic acid, maleic anhydride, and butanol could be competitive. Results of analysis by a computer model of the petrochemical industry indicate that with furfural markets additional to these three furfural processes, over 2.5 x 10/sup 9/ gal of ethanol could be marketed at about $1.00/gal. Converting the xylose stream to ethanol has about the same effect on the selling price of ethanol as the furfural credit. The greatest ethanol production will result from xylose fermentation, but the furfural credit offers large near-term profits and has a more diversified impact on reducing petroleum product demand. 6 figures, 17 tables.

  12. Integrated process for preparing a carboxylic acid from an alkane

    DOEpatents

    Benderly, Abraham; Chadda, Nitin; Sevon, Douglass

    2011-12-20

    The present invention relates to an integrated process for producing unsaturated carboxylic acids from the corresponding C.sub.2-C.sub.4 alkane. The process begins with performance of thermally integrated dehydrogenation reactions which convert a C.sub.2-C.sub.4 alkane to its corresponding C.sub.2-C.sub.4 alkene, and which involve exothermically converting a portion of an alkane to its corresponding alkene by oxidative dehydrogenation in an exothermic reaction zone, in the presence of oxygen and a suitable catalyst, and then feeding the products of the exothermic reaction zone to an endothermic reaction zone wherein at least a portion of the remaining unconverted alkane is endothermically dehydrogenated to form an additional quantity of the same corresponding alkene, in the presence of carbon dioxide and an other suitable catalyst. The alkene products of the thermally integrated dehydrogenation reactions are then provided to a catalytic vapor phase partial oxidation process for conversion of the alkene to the corresponding unsaturated carboxylic acid or nitrile. Unreacted alkene and carbon dioxide are recovered from the oxidation product stream and recycled back to the thermally integrated dehydrogenation reactions.

  13. SIMPLE SAMPLE CLEAN UP PROCEDURE AND HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC METHOD FOR THE ANALYSIS OF CYANURIC ACID IN HUMAN URINE

    EPA Science Inventory

    Cyanuric acide (CA) is widely used as a chlorine stabilizer in outdoor pools. No simple method exists for CA measurement in the urine of exposed swimmers. The high hydrophilicity of CA makes usage of solid phase sorbents to extract it from urine nearly impossible because of samp...

  14. Supercritical fluids cleaning

    SciTech Connect

    Butner, S.; Hjeresen, D.; Silva, L.; Spall, D.; Stephenson, R.

    1991-01-01

    This paper discusses a proposed multi-party research and development program which seeks to develop supercritical fluid cleaning technology as an alternative to existing solvent cleaning applications. While SCF extraction technology has been in commercial use for several years, the use of these fluids as cleaning agents poses several new technical challenges. Problems inherent in the commercialization of SCF technology include: the cleaning efficacy and compatibility of supercritical working fluids with the parts to be cleaned must be assessed for a variety of materials and components; process parameters and equipment design Have been optimized for extractive applications and must be reconsidered for application to cleaning; and co-solvents and entrainers must be identified to facilitate the removal of polar inorganic and organic contaminants, which are often not well solvated in supercritical systems. The proposed research and development program would address these issues and lead to the development and commercialization of viable SCF-based technology for precision cleaning applications. This paper provides the technical background, program scope, and delineates the responsibilities of each principal participant in the program.

  15. REVIEW OF ALTERNATIVE ENHANCED CHEMICAL CLEANING OPTIONS FOR SRS WASTE TANKS

    SciTech Connect

    Hay, M.; Koopman, D.

    2009-08-01

    A literature review was conducted to support the Task Technical and Quality Assurance Plan for Alternative Enhanced Chemical Cleaning (AECC) for sludge heel removal funded as part of the EM-21 Engineering and Technology program. The goal was to identify potential technologies or enhancements to the baseline oxalic acid cleaning process for chemically dissolving or mobilizing Savannah River Site (SRS) sludge heels. The issues with the potentially large volume of oxalate solids generated from the baseline process have driven an effort to find an improved or enhanced chemical cleaning technology for the tank heels. This literature review builds on a previous review conducted in 2003. A team was charged with evaluating the information in these reviews and developing recommendations of alternative technologies to pursue. The new information in this report supports the conclusion of the previous review that oxalic acid remains the chemical cleaning agent of choice for dissolving the metal oxides and hydroxides found in sludge heels in carbon steel tanks. The potential negative impact of large volumes of sodium oxalate on downstream processes indicates that the amount of oxalic acid used for chemical cleaning needs to be minimized as much as possible or the oxalic acid must be destroyed prior to pH adjustment in the receipt tank. The most straightforward way of minimizing the volume of oxalic acid needed for chemical cleaning is through more effective mechanical cleaning. Using a mineral acid to adjust the pH of the sludge prior to adding oxalic acid may also help to minimize the volume of oxalic acid used in chemical cleaning. If minimization of oxalic acid proves insufficient in reducing the volume of oxalate salts, several methods were found that could be used for oxalic acid destruction. For some waste tank heels, another acid or even caustic treatment (or pretreatment) might be more appropriate than the baseline oxalic acid cleaning process. Caustic treatment of high

  16. Extraction of humic acid by coacervate: investigation of direct and back processes.

    PubMed

    Ghouas, H; Haddou, B; Kameche, M; Derriche, Z; Gourdon, C

    2012-02-29

    The two aqueous phases extraction process is widely used in environmental clean up of industrial effluents and fine chemical products for their reuse. This process can be made by cloud point of polyethoxylated alcohols and micellar solubilization phenomenon. It is commonly called "coacervate extraction" and is used, in our case, for humic acid extraction from aqueous solution at 100mg/L. The surfactants used are alcohol polyethoxylate and alkylphenol polyethoxylate. Phase diagrams of binary water/surfactant and pseudo-binary are plotted. The extraction results are expressed by the following responses: percentage of solute extracted, E (%), residual concentrations of solute and surfactant in dilute phase (X(s,w), and X(t,w) respectively) and volume fraction of coacervate at equilibrium (ϕ). For each parameter, the experimental results are fitted to empirical equations in three dimensions. The aim of this study is to find out the best compromise between E and ϕC. The comparison between experimental and calculated values allows models validation. Sodium sulfate, cetyltrimethylammonium bromide (CTAB) addition and pH effect are also studied. Finally, the possibility of recycling the surfactant has been proved. PMID:22260753

  17. Passive extraction and clean-up of phenoxy acid herbicides in samples from a groundwater plume using hollow fiber supported liquid membranes.

    PubMed

    Liu, Jing-Fu; Toräng, Lars; Mayer, Philipp; Jönsson, Jan Ake

    2007-08-10

    Hollow fiber supported liquid membranes were applied for the passive extraction of phenoxy acid herbicides from water samples. Polypropylene hollow fiber membranes (240 microm i.d., 30 microm wall thickness, 0.05 microm pore size, 30 cm length) were impregnated with 2.0% tri-n-octylphosphine oxide (TOPO) in di-n-hexyl ether in the pores of the fiber wall to form a liquid membrane. They were then filled with basic solution in the lumen as acceptor and finally placed into the sample (donor). Complete extraction of phenoxy acid herbicides including 2,4-D, MCPA, dichlorprop, and mecoprop from an acidified sample (4 mL, adjusted to pH 1.5 with HCl) into basic acceptor (10 microL of 0.2M NaOH) was achieved after 4 h of shaking (100 rpm) resulting in an enrichment factor of 400 times. The acceptor was then neutralized by addition of HCl and injected into a HPLC system for the determination of the phenoxy acid herbicides. Environmentally relevant salinity (0-3.5% NaCl) and dissolved organic matter (0-25 mg/L of dissolved organic carbon) had no significant effect on the extraction. The method provided extraction efficiencies of more than 91%, detection limits of 0.3-0.6 microg/L, and combined extraction and clean up in one single step. This procedure was applied to determine aqueous concentrations of phenoxy acid herbicides in groundwater samples collected from an old dumping site (Cheminova, Denmark) with detected concentrations up to 5800 microg/L. Although the samples were very dirty with large amounts of suspended particles, non-aqueous phase liquids (NAPLs) and dissolved organic matters, good spike recoveries (80-126%) were obtained for 10 of the 11 samples. PMID:17449052

  18. Effective cleaning and sanitizing of polysulfone ultrafiltration membrane systems.

    PubMed

    Bohner, H F; Bradley, R L

    1992-03-01

    Polysulfone UF membranes that were soiled by Cheddar cheese whey were successfully cleaned in place. This cleaning procedure was completed in about 1 h. Most cleaning chemicals used were common and inexpensive. The cleaning procedure consisted of rinsing the membrane system for 2 min with water initially and after each cleaning solution. Sodium hydroxide at pH 11.0, with .1% of a nonionic surfactant added, was circulated for 20 min. After a 2-min rinse with water, a 1:1 mixture of nitric and phosphoric acids at pH 2 was circulated for 20 min and rinsed again with water. Finally, sodium hydroxide at pH 11.0, with 200 ppm of sodium hypochlorite added, was circulated for 20 min and rinsed. All cleaning solutions and all rinse waters were at 54 degrees C. Membranes cleaned by this procedure were found to be free from whey residue under examination by scanning electron microscopy. The cleaning process did not damage the membranes even when it was used continuously for 300 h. Microbial populations on the membrane were estimated by incubating small (4-cm2) sections of membrane in screw-cap vials filled with trypticase soy broth. From the portion of vials showing growth after 72 h at 32 degrees C, a most probable microbial population was calculated. Santizing cleaned polysulfone UF membranes with 100 ppm of sodium hypochlorite or 100 ppm of dichloroisocyanurate at 54 degrees C resulted in membranes free from viable microorganisms. When dichloroisocyanurate was used at 10 degrees C and 200 ppm, a most probable microbial population of 290/m2 was found. No microbial growth was detected when cleaned and sanitized membranes were stored in tap water for 24 h. This technique for cleaning UF membranes does not require the use of a holding solution containing santizers to control the growth of residual microorganisms. PMID:1569262

  19. Reversible and irreversible processing of biogenic olefins on acidic aerosols

    NASA Astrophysics Data System (ADS)

    Liggio, J.; Li, S.-M.

    2008-04-01

    Recent evidence has suggested that heterogeneous chemistry of oxygenated hydrocarbons, primarily carbonyls, plays a role in the formation of secondary organic aerosol (SOA); however, evidence is emerging that direct uptake of alkenes on acidic aerosols does occur and can contribute to SOA formation. In the present study, significant uptake of monoterpenes, oxygenated monoterpenes and sesquiterpenes to acidic sulfate aerosols is found under various conditions in a reaction chamber. Proton transfer mass spectrometry is used to quantify the organic gases, while an aerosol mass spectrometer is used to quantify the organic mass uptake and obtain structural information for heterogeneous products. Aerosol mass spectra are consistent with several mechanisms including acid catalyzed olefin hydration, cationic polymerization and organic ether formation, while measurable decreases in the sulfate mass on a per particle basis suggest that the formation of organosulfate compounds is also likely. A portion of the heterogeneous reactions appears to be reversible, consistent with reversible olefin hydration reactions. A slow increase in the organic mass after a fast initial uptake is attributed to irreversible reactions, consistent with polymerization and organosulfate formation. Uptake coefficients (γ) were estimated for a fast initial uptake governed by the mass accommodation coefficient (α) and ranged from 1×10-6-2.5×10-2. Uptake coefficients for a subsequent slower reactive uptake ranged from 1×10-7-1×10-4. These processes may potentially lead to a considerable amount of SOA from the various biogenic hydrocarbons under acidic conditions, which can be highly significant for freshly nucleated aerosols, particularly given the large array of atmospheric olefins.

  20. Ultrasonic cleaning: Fundamental theory and application

    NASA Technical Reports Server (NTRS)

    Fuchs, F. John

    1995-01-01

    This presentation describes: the theory of ultrasonics, cavitation and implosion; the importance and application of ultrasonics in precision cleaning; explanations of ultrasonic cleaning equipment options and their application; process parameters for ultrasonic cleaning; and proper operation of ultrasonic cleaning equipment to achieve maximum results.

  1. METHOD OF CLEANING METAL SURFACES

    DOEpatents

    Winkler, H.W.; Morfitt, J.W.; Little, T.H.

    1959-05-19

    Cleaning fluids for removing deposits from metal surfaces are described. The cleaning agents of the invention consist of aqueous nitric acid and an amhydrous nitrate salt of a metal which is lower in the electromotive series than the element of the deposit to be removed. In general, the salt content of thc cleaning agents ranged from 10 to 90%, preferably from 10 to 40% by weight; and the balance of the composition comprises nitric acid of any strength from extremely dilute up to concentrated strength.

  2. Solder Flux Residues and Humidity-Related Failures in Electronics: Relative Effects of Weak Organic Acids Used in No-Clean Flux Systems

    NASA Astrophysics Data System (ADS)

    Verdingovas, Vadimas; Jellesen, Morten Stendahl; Ambat, Rajan

    2015-04-01

    This paper presents the results of humidity testing of weak organic acids (WOAs), namely adipic, succinic, glutaric, dl-malic, and palmitic acids, which are commonly used as activators in no-clean solder fluxes. The study was performed under humidity conditions varying from 60% relative humidity (RH) to ˜99%RH at 25°C. The following parameters were used for characterization of WOAs: mass gain due to water adsorption and deliquescence of the WOA (by quartz crystal microbalance), resistivity of the water layer formed on the printed circuit board (by impedance spectroscopy), and leakage current measured using the surface insulation resistance pattern in the potential range from 0 V to 10 V. The combined results indicate the importance of the WOA chemical structure for the water adsorption and therefore conductive water layer formation on the printed circuit board assembly (PCBA). A substantial increase of leakage currents and probability of electrochemical migration was observed at humidity levels above the RH corresponding to the deliquescence point of WOAs present as contaminants on the printed circuit boards. The results suggest that use of solder fluxes with WOAs having higher deliquescence point could improve the reliability of electronics operating under circumstances in which exposure to high humidity is likely to occur.

  3. Plasma-assisted cleaning by electrostatics (PACE)

    NASA Astrophysics Data System (ADS)

    Lytle, W. M.; Neumann, M. J.; Ruzic, D. N.

    2006-03-01

    As feature sizes shrink, particle contamination on EUV masks used in the fabrication process of semiconductor chips is an increasingly difficult problem that leads to lower wafer throughput and higher costs of chip production. Current practices to remove particulates off of masks include using a sulfuric acid bath, ultrasonic cleansing, and rinsing in de-ionized water. However, nanometer-scale etching occurs through this cleaning process in addition to the presence of residual contamination due to the chemicals used, which leads to feature devolution. Currently, pellicles are used to protect the reticle with the pellicle being transparent to 193 nm light; however with current EUV technology being developed for 13.5 nm light, the pellicle is no longer transparent at this wavelength and thus cannot be used. Other mask-cleaning processes such as laser-induce plasma cleaning (LIP) run the risk of substrate damage due to potentially destructive methods. Plasma-assisted electrostatic cleaning involves using a potential drop in a plasma sheath electric field and charge imbalance between the particle and the substrate to propel the nanoparticles off the surface. Through applying a positive bias to the substrate and using a weak local plasma to charge the particles, the contamination is removed from the surface. As the particle size decreases the amount of time to charge the particle is longer thus leading to a longer removal period. However, as long as the particle is in the plasma sheath region, there is no theoretical limit on the size of the particle removed.

  4. ANALYSIS OF SAMPLES FROM TANK 5F CHEMICAL CLEANING

    SciTech Connect

    Poirier, M.; Fink, S.

    2011-03-07

    The Savannah River Site (SRS) is preparing Tank 5F for closure. The first step in preparing the tank for closure is mechanical sludge removal. Following mechanical sludge removal, SRS performed chemical cleaning with oxalic acid to remove the sludge heel. Personnel are currently assessing the effectiveness of the chemical cleaning. SRS personnel collected liquid samples during chemical cleaning and submitted them to Savannah River National Laboratory (SRNL) for analysis. Following chemical cleaning, they collected a solid sample (also known as 'process sample') and submitted it to SRNL for analysis. The authors analyzed these samples to assess the effectiveness of the chemical cleaning process. The conclusions from this work are: (1) With the exception of iron, the dissolution of sludge components from Tank 5F agreed with results from the actual waste demonstration performed in 2007. The fraction of iron removed from Tank 5F by chemical cleaning was significantly less than the fraction removed in the SRNL demonstrations. The likely cause of this difference is the high pH following the first oxalic acid strike. (2) Most of the sludge mass remaining in the tank is iron and nickel. (3) The remaining sludge contains approximately 26 kg of barium, 37 kg of chromium, and 37 kg of mercury. (4) Most of the radioactivity remaining in the residual material is beta emitters and {sup 90}Sr. (5) The chemical cleaning removed more than {approx} 90% of the uranium isotopes and {sup 137}Cs. (6) The chemical cleaning removed {approx} 70% of the neptunium, {approx} 83% of the {sup 90}Sr, and {approx} 21% of the {sup 60}Co. (7) The chemical cleaning removed less than 10% of the plutonium, americium, and curium isotopes. (8) The chemical cleaning removed more than 90% of the aluminium, calcium, and sodium from the tank. (9) The cleaning operations removed 61% of lithium, 88% of non-radioactive strontium, and 65% of zirconium. The {sup 90}Sr and non-radioactive strontium were measured

  5. Cleaning devices

    NASA Technical Reports Server (NTRS)

    Schneider, Horst W. (Inventor)

    1981-01-01

    Cleaning devices are described which include a vacuum cleaner nozzle with a sharp rim for directing incoming air down against the floor; a vacuum cleaner wherein electrostatically charged brushes that brush dirt off a floor, are electrically grounded to remove charges that could tend to hold dirt to the brushes; a vacuum cleaner head having slots that form a pair of counter-rotating vortices, and that includes an outlet that blows a stream of air at the floor region which lies between the vortices; a cleaning device that sweeps a group of brushes against the ground along a first direction, and then sweeps them along the same ground area but in a second direction angled from the first by an amount such as 90.degree., to sweep up particles lying in crevices extending along any direction; a device that gently cleans a surface to remove bacteria for analysis, including an inclined wall along which cleaning fluid flows onto the surface, a vacuum chamber for drawing in the cleaning fluid, and a dividing wall spaced slightly from the surface to separate the fluid source from the vacuum cleaner chamber; and a device for providing pulses of pressured air including a chamber to which pressured air is supplied, a ball that circulates around the chamber to repeatedly close an outlet, and an air source that directs air circumferentially to move the ball around the chamber.

  6. Acid deposition: Atmospheric processes in Eastern North America

    SciTech Connect

    Not Available

    1983-01-01

    This report examines scientific evidence on the relationship between emissions of acid-forming pollutants and damage to sensitive ecosystems from acid rain and other forms of acid deposition. The report's conclusions represent the most authoritative statement yet that reductions in emissions of these pollutants will result in proportional reductions in acid rain.

  7. Automated cleaning of electronic components

    SciTech Connect

    Drotning, W.

    1994-03-01

    Environmental and operator safety concerns are leading to the elimination of trichloroethylene (TCE) and chlorofluorocarbon (CFC) solvents in electronic component cleaning processes that remove rosin flux, organic and inorganic contamination, and particulates. 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. In addition, the use of robotic and automated systems can reduce the manual handling of parts that necessitates additional cleaning. 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.

  8. 21 CFR 173.280 - Solvent extraction process for citric acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Solvent extraction process for citric acid. 173.280 Section 173.280 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Solvent extraction process for citric acid. A solvent extraction process for recovery of citric acid...

  9. 21 CFR 173.280 - Solvent extraction process for citric acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Solvent extraction process for citric acid. 173.280 Section 173.280 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... extraction process for citric acid. A solvent extraction process for recovery of citric acid...

  10. The impact of different cleaning processes on the laser damage threshold of antireflection coatings for Z-Backlighter optics at Sandia National Laboratories

    NASA Astrophysics Data System (ADS)

    Field, Ella; Bellum, John; Kletecka, Damon

    2014-09-01

    The Z-Backlighter lasers at Sandia National Laboratories are kilojoule class, pulsed systems operating with ns pulse lengths at 527 nm and ns and sub-ps pulse lengths at 1054 nm (www.z-beamlet.sandia.gov), and are linked to the most powerful and energetic x-ray source in the world, the Z-Accelerator (http://www.sandia.gov/z-machine/). An important Z-Backlighter optic is a flat, fused silica optic measuring 32.5 cm × 32.5 cm × 1 cm with an antireflection (AR) coating on both sides. It is used as a debris shield to protect other Z-Backlighter laser optics from high-velocity particles released by the experiments conducted in the Z-Accelerator. Each experiment conducted in the Z-Accelerator releases enough debris to cloud the surface of a debris shield, which means that a debris shield cannot be used for more than one experiment. Every year, the large optics coating facility [1] at Sandia provides AR coatings for approximately 50 debris shields, in addition to AR coatings for numerous other meter-class Z-Backlighter lenses and windows. As with all Z-Backlighter optical coatings, these AR coatings must have a high laser-induced damage threshold (LIDT) in order to withstand the powerful Z-Backlighter laser fluences. Achieving a good LIDT depends not only on the coating deposition processes but also on the polishing and cleaning processes used to prepare the coated and uncoated surfaces [2]. We spend a lot of time, both before and after the coatings have been deposited, manually cleaning the optics, including the debris shields, even though they are an expendable type of optic. Therefore, in this study we have tested new cleaning methods in addition to our current method to determine their impact on the LIDT of AR coatings, and conclude whether a shorter-duration or less labor-intensive cleaning process would suffice.

  11. Changes in lipid composition, fatty acid profile and lipid oxidative stability during Cantonese sausage processing.

    PubMed

    Qiu, Chaoying; Zhao, Mouming; Sun, Weizheng; Zhou, Feibai; Cui, Chun

    2013-03-01

    Lipid composition, fatty acid profile and lipid oxidative stability were evaluated during Cantonese sausage processing. Free fatty acids increased with concomitant decrease of phospholipids. Total content of free fatty acids at 72 h in muscle and adipose tissue was 7.341 mg/g and 3.067 mg/g, respectively. Total amount of saturated, monounsaturated and polyunsaturated fatty acids (SFA, MUFA, and PUFA) in neutral lipid exhibited a little change during processing, while the proportion of PUFA significantly decreased in the PL fraction. The main triacylglycerols were POO+SLO+OOO, PSO (P = palmitic acid, O = oleic acid, L = linoleic acid, S = stearic acid), and a preferential hydrolysis of palmitic, oleic and linoleic acid was observed. Phosphatidylcholines (PC) and phosphatidylethanolamines (PE) were the main components of phospholipids and PE exhibited the most significant degradation during processing. Thiobarbituric acid values (TBARS) increased while peroxide values and hexanal contents varied during processing. PMID:23273460

  12. SULFURIC ACID REMOVAL PROCESS EVALUATION: SHORT-TERM RESULTS

    SciTech Connect

    Gary M. Blythe; Richard McMillan

    2002-02-04

    The objective of this project is to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. Sulfuric acid controls are becoming of increasing interest to utilities with coal-fired units for a number of reasons. Sulfuric acid is a Toxic Release Inventory species, a precursor to acid aerosol/condensable emissions, and can cause a variety of plant operation problems such as air heater plugging and fouling, back-end corrosion, and plume opacity. These issues will likely be exacerbated with the retrofit of SCR for NO{sub x} control on some coal-fired plants, as SCR catalysts are known to further oxidize a portion of the flue gas SO{sub 2} to SO{sub 3}. The project is testing the effectiveness of furnace injection of four different calcium- and/or magnesium-based alkaline sorbents on full-scale utility boilers. These reagents have been tested during four one- to two-week tests conducted on two First Energy Bruce Mansfield Plant units. One of the sorbents tested was a magnesium hydroxide slurry produced from a wet flue gas desulfurization system waste stream, from a system that employs a Thiosorbic{reg_sign} Lime scrubbing process. The other three sorbents are available commercially and include dolomite, pressure-hydrated dolomitic lime, and commercial magnesium hydroxide. The dolomite reagent was injected as a dry powder through out-of-service burners, while the other three reagents were injected as slurries through air-atomizing nozzles into the front wall of upper furnace, either across from the nose of the furnace or across from the pendant superheater tubes. After completing the four one- to two-week tests, the most promising sorbents were selected for longer-term (approximately 25-day) full-scale tests. The longer-term tests are being conducted to confirm the effectiveness of the sorbents tested over extended operation and to determine balance-of-plant impacts. This reports presents

  13. SULFURIC ACID REMOVAL PROCESS EVALUATION: SHORT-TERM RESULTS

    SciTech Connect

    Gary M. Blythe; Richard McMillan

    2002-03-04

    The objective of this project is to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. Sulfuric acid controls are becoming of increasing interest to utilities with coal-fired units for a number of reasons. Sulfuric acid is a Toxic Release Inventory species, a precursor to acid aerosol/condensable emissions, and can cause a variety of plant operation problems such as air heater plugging and fouling, back-end corrosion, and plume opacity. These issues will likely be exacerbated with the retrofit of SCR for NOX control on some coal-fired plants, as SCR catalysts are known to further oxidize a portion of the flue gas SO{sub 2} to SO{sub 3}. The project is testing the effectiveness of furnace injection of four different calcium- and/or magnesium-based alkaline sorbents on full-scale utility boilers. These reagents have been tested during four one- to two-week tests conducted on two FirstEnergy Bruce Mansfield Plant units. One of the sorbents tested was a magnesium hydroxide slurry produced from a wet flue gas desulfurization system waste stream, from a system that employs a Thiosorbic{reg_sign} Lime scrubbing process. The other three sorbents are available commercially and include dolomite, pressure-hydrated dolomitic lime, and commercial magnesium hydroxide. The dolomite reagent was injected as a dry powder through out-of-service burners, while the other three reagents were injected as slurries through air-atomizing nozzles into the front wall of upper furnace, either across from the nose of the furnace or across from the pendant superheater tubes. After completing the four one- to two-week tests, the most promising sorbents were selected for longer-term (approximately 25-day) full-scale tests. The longer-term tests are being conducted to confirm the effectiveness of the sorbents tested over extended operation and to determine balance-of-plant impacts. This reports presents the

  14. Oxalate Mass Balance During Chemical Cleaning in Tank 5F

    SciTech Connect

    Poirier, M.; Fink, S.

    2011-07-08

    The Savannah River Site (SRS) is preparing Tank 5F for closure. The first step in preparing the tank for closure is mechanical sludge removal. Following mechanical sludge removal, SRS performed chemical cleaning with oxalic acid to remove the sludge heel. Personnel are currently assessing the effectiveness of the chemical cleaning to determine whether the tank is ready for closure. SRS personnel collected liquid samples during chemical cleaning and submitted them to Savannah River National Laboratory (SRNL) for analysis. Following chemical cleaning, they collected a solid sample (also known as 'process sample') and submitted it to SRNL for analysis. The authors analyzed these samples to assess the effectiveness of the chemical cleaning process. Analysis of the anions showed the measured oxalate removed from Tank 5F to be approximately 50% of the amount added in the oxalic acid. To close the oxalate mass balance, the author collected solid samples, leached them with nitric acid, and measured the concentration of cations and anions in the leachate.

  15. Development of an industrializable fermentation process for propionic acid production.

    PubMed

    Stowers, Chris C; Cox, Brad M; Rodriguez, Brandon A

    2014-05-01

    Propionic acid (PA) is a short-chain fatty acid with wide industrial application including uses in pharmaceuticals, herbicides, cosmetics, and food preservatives. As a three-carbon building block, PA also has potential as a precursor for high-volume commodity chemicals such as propylene. Currently, most PA is manufactured through petrochemical routes, which can be tied to increasing prices and volatility due to difficulty in demand forecasting and feedstock availability. Herein described are research advancements to develop an industrially feasible, renewable route to PA. Seventeen Propionibacterium strains were screened using glucose and sucrose as the carbon source to identify the best platform strain. Propionibacterium acidipropionici ATCC 4875 was selected as the platform strain and subsequent fermentation optimization studies were performed to maximize productivity and yield. Fermentation productivity was improved three-fold to exceed 2 g/l/h by densifying the inoculum source. Byproduct levels, particularly lactic and succinic acid, were reduced by optimizing fermentor headspace pressure and shear. Following achievement of commercially viable productivities, the lab-grade medium components were replaced with industrial counterparts to further reduce fermentation costs. A pure enzymatically treated corn mash (ECM) medium improved the apparent PA yield to 0.6 g/g (PA produced/glucose consumed), but it came at the cost of reduced productivity. Supplementation of ECM with cyanocobalamin restored productivity to near lab-grade media levels. The optimized ECM recipe achieved a productivity of 0.5 g/l/h with an apparent PA yield of 0.60 g/g corresponding to a media cost <1 USD/kg of PA. These improvements significantly narrow the gap between the fermentation and incumbent petrochemical processes, which is estimated to have a manufacturing cost of 0.82 USD/kg in 2017. PMID:24627047

  16. Reversible and irreversible processing of biogenic olefins on acidic aerosols

    NASA Astrophysics Data System (ADS)

    Liggio, J.; Li, S.-M.

    2007-08-01

    Recent evidence has suggested that heterogeneous chemistry of oxygenated hydrocarbons, primarily carbonyls, plays a role in the formation of secondary organic aerosol (SOA); however, evidence is emerging that direct uptake of alkenes on acidic aerosols does occur and can contribute to SOA formation. In the present study, significant uptake of monoterpenes, oxygenated monoterpenes and sesquiterpenes to acidic sulfate aerosols is found under various conditions in a reaction chamber. Proton transfer mass spectrometry is used to quantify the organic gases, while an aerosol mass spectrometer is used to quantify the organic mass uptake and obtain structural information for heterogeneous products. Aerosol mass spectra are consistent with several mechanisms including acid catalyzed olefin hydration, cationic polymerization and organic ester formation, while measurable decreases in the sulfate mass on a per particle basis suggest that the formation of organosulfate compounds is also likely. A portion of the heterogeneous reactions appears to be reversible, consistent with reversible olefin hydration reactions. A slow increase in the organic mass after a fast initial uptake is attributed to irreversible reactions, consistent with polymerization and organosulfate formation. Uptake coefficients (γ) were estimated for a fast initial uptake governed by the mass accommodation coefficient (α) and ranged from 1×10-6-2.5×10-2. Uptake coefficients for a subsequent slower reactive uptake ranged from 1×10-7-1×10-4. These processes are estimated to potentially produce greater than 2.5 μg m-3 of SOA from the various biogenic hydrocarbons under atmospheric conditions, which can be highly significant given the large array of atmospheric olefins.

  17. STATUS OF CHEMICAL CLEANING OF WASTE TANKS AT THE SAVANNAH RIVER SITE F TANK FARM CLOSURE PROJECT - 9114

    SciTech Connect

    Thaxton, D; Geoff Clendenen, G; Willie Gordon, W; Samuel Fink, S; Michael Poirier, M

    2008-12-31

    Chemical Cleaning is currently in progress for Tanks 5 and 6 at the Savannah River Site. The Chemical Cleaning process is being utilized to remove the residual waste heel remaining after completion of Mechanical Sludge Removal. This work is required to prepare the tanks for closure. Tanks 5 and 6 are 1950s vintage carbon steel waste tanks that do not meet current containment standards. These tanks are 22.9 meters (75 feet) in diameter, 7.5 meters (24.5 feet) in height, and have a capacity of 2.84E+6 liters (750,000 gallons). Chemical Cleaning adds 8 wt % oxalic acid to the carbon steel tank to dissolve the remaining sludge heel. The resulting acidic waste solution is transferred to Tank 7 where it is pH adjusted to minimize corrosion of the carbon steel tank. The Chemical Cleaning flowsheet includes multiple strikes of acid in each tank. Acid is delivered by tanker truck and is added to the tanks through a hose assembly connected to a pipe penetration through the tank top. The flowsheet also includes spray washing with acid and water. This paper includes an overview of the configuration required for Chemical Cleaning, the planned flowsheet, and an overview of technical concerns associated with the process. In addition, the current status of the Chemical Cleaning process in Tanks 5 and 6, lessons learned from the execution of the process, and the path forward for completion of cleaning in Tanks 5 and 6 will also be discussed.

  18. Chemical cleaning of porous stainless steel cross-flow filter elements for nuclear waste applications

    SciTech Connect

    Billing, Justin M.; Daniel, Richard C.; Hallen, Richard T.; Schonewill, Philip P.; Shimskey, Rick W.; Peterson, Reid A.

    2011-05-10

    The Waste Treatment and Immobilization Plant (WTP) currently under construction for treatment of High-Level Waste (HLW) at the Hanford Site will rely on cross-flow ultrafiltration to provide solids-liquid separation as a core part of the treatment process. To optimize process throughput, periodic chemical cleaning of the porous stainless steel filter elements has been incorporated into the design of the plant. It is currently specified that chemical cleaning with nitric acid will occur after significant irreversible membrane fouling is observed. Irreversible fouling is defined as fouling that cannot be removed by backpulsing the filter. PNNL has investigated chemical cleaning processes as part of integrated tests with HLW simulants and with actual Hanford tank wastes. To quantify the effectiveness of chemical cleaning, the residual membrane resistance after cleaning was compared against the initial membrane resistance for each test in a series of long-term fouling tests. The impact of the small amount of residual resistance in these tests could not be separated from other parameters and the historical benchmark of >1 GPM/ft2 for clean water flux was determined to be an adequate metric for chemical cleaning. Using the results from these tests, a process optimization strategy is presented suggesting that for the simulant material under test, the value of chemical cleaning may be suspect. The period of enhanced filtration may not be enough to offset the down time required for chemical cleaning, without respect to the other associated costs.

  19. Study of the petroleum schedules thermal cleaning process from asphalt, ressin and paraffin deposits using low- temperature plasma

    NASA Astrophysics Data System (ADS)

    Samigullin, A. D.; Galiakbarov, A. T.; Galiakbarov, R. T.

    2016-01-01

    Petroleum industry uses large amount of pumping and compression pipes. Carrying out the whole range of repair works requires cleaning of the pipe inner surface from deposits which appeared in it during operation [1]. The task of asphalt, resin and paraffin deposits control remains one of the most essential for the branch. The article deals with thermal method and device for asphalt, resin and paraffin deposits removal from pumping and compression pipes inner surface, describes and provides the device application scope for cleaning the pumping and compression pipes inner surface. To deal with borehole equipment and pipe systems waxing problem various deposit prevention and removal methods are used, including mechanical, thermal, chemical, combined and nonconventional methods.

  20. X-ray photoelectron spectroscopy analysis of cleaning procedures for synchrotron radiation beamline materials at the Advanced Photon Source

    SciTech Connect

    Li, Y.; Ryding, D.; Liu, C.; Kuzay, T.M.; McDowell, M.W.; Rosenberg, R.A.

    1995-05-01

    TZM (a high-temperature molybdenum alloy), machinable tungsten, and 304 stainless steel were cleaned using environmentally safe, commercially available cleaning detergents. The surface cleanliness was evaluated by x-ray photoelectron spectroscopy. It was found that a simple alkaline detergent is very effective at removal of organic and inorganic surface contaminants or foreign particle residue from machining processes. The detergent can be used with ultrasonic agitation at 140 {degree}F to clean the TZM molybdenum, machinable tungsten, and 304 stainless steel. A citric-acid-based detergent was also found to be effective at cleaning metal oxides, such as iron oxide, molybdenum oxide, as well as tungsten oxides, at mild temperatures with ultrasonic agitation, and it can be used to replace strong inorganic acids to improve cleaning safety and minimize waste disposal and other environmental problems. The efficiency of removing the metal oxides depends on both cleaning temperature and time. {copyright} {ital 1995} {ital American} {ital Vacuum} {ital Society}

  1. X-ray photoelectron spectroscopy analysis of cleaning procedures for synchrotron radiation beamline materials at the Advanced Photon Source

    SciTech Connect

    Li, Y.; Ryding, D.; Liu, C.; Kuzay, T.M.; McDowell, M.W.; Rosenberg, R.A.

    1994-12-31

    TZM (a high temperature molybdenum alloy), machinable tungsten, and 304 stainless steel were cleaned using environmentally safe, commercially available cleaning detergents. The surface cleanliness was evaluated by x-ray photoelectron spectroscopy (XPS). It was found that a simple alkaline detergent is very effective at removal of organic and inorganic surface contaminants or foreign particle residue from machining processes. The detergent can be used with ultrasonic agitation at 140 F to clean the TZM molybdenum, machinable tungsten, and 304 stainless steel. A citric-acid-based detergent was also found to be effective at cleaning metal oxides, such as iron oxide, molybdenum oxide, as well as tungsten oxides at mild temperatures with ultrasonic agitation, and it can be used to replace strong inorganic acids to improve cleaning safety and minimize waste disposal and other environmental problems. The efficiency of removing the metal oxides depends on both cleaning temperature and time.

  2. Cleaning Services.

    ERIC Educational Resources Information Center

    Sharpton, James L.

    This curriculum guide provides cleaning services instructional materials for a ninth- and tenth-grade Coordinated Vocational Education and Training: Home and Community Services program. It includes 2 sections and 11 instructional units. Each unit of instruction consists of eight basic components: performance objectives, teacher activities,…

  3. Reductive stripping process for the recovery of uranium from wet-process phosphoric acid

    DOEpatents

    Hurst, Fred J.; Crouse, David J.

    1984-01-01

    A reductive stripping flow sheet for recovery of uranium from wet-process phosphoric acid is described. Uranium is stripped from a uranium-loaded organic phase by a redox reaction converting the uranyl to uranous ion. The uranous ion is reoxidized to the uranyl oxidation state to form an aqueous feed solution highly concentrated in uranium. Processing of this feed through a second solvent extraction cycle requires far less stripping reagent as compared to a flow sheet which does not include the reductive stripping reaction.

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

    NASA Astrophysics Data System (ADS)

    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

  5. ROLE OF SOIL ORGANIC ACIDS IN MINERAL WEATHERING PROCESSES

    EPA Science Inventory

    The soluble organic acids in soils consist largely of complex mixtures of polymeric compounds referred to collectively as fluvic and humic acids. These compounds are relatively refactory, and are broken down only slowly by bacteria. ow-molecular-mass acids (e.g., acetic, oxalic, ...

  6. Influence of different acid and alkaline cleaning agents on the effects of irrigation of synthetic dairy factory effluent on soil quality, ryegrass growth and nutrient uptake.

    PubMed

    Liu, Y-Y; Haynes, R J

    2013-01-01

    The aim of this study was to examine the effects of replacement of phosphoric acid with nitric or acetic acid, and replacement of NaOH with KOH, as cleaning agents in dairy factories, on the effects that irrigation of dairy factory effluent (DFE) has on the soil-plant system. A 16-week greenhouse study was carried out in which the effects of addition of synthetic dairy factory effluent containing (a) milk residues alone or milk residues plus (b) H(3)PO(4)/NaOH, (c) H(3)PO(4)/HNO(3)/NaOH or (d) CH(3)COOH/KOH, on soil's chemical, physical and microbial properties and perennial ryegrass growth and nutrient uptake were investigated. The cumulative effect of DFE addition was to increase exchangeable Na, K, Ca, Mg, exchangeable sodium percentage, microbial biomass C and N and basal respiration in the soil. Dry matter yields of ryegrass were increased by additions of DFE other than that containing CH(3)COOH. Plant uptake of P, Ca and Mg was in the same order as their inputs in DFE but for Na; inputs were an order of magnitude greater than plant uptake. Replacement of NaOH by KOH resulted in increased accumulation of exchangeable K. The effects of added NaOH and KOH on promoting breakdown of soil aggregates during wet sieving (and formation of a < 0.25 mm size class) were similar. Replacement of H(2)PO(4) by HNO(3) is a viable but CH(3)COOH appears to have detrimental effects on plant growth. Replacement of NaOH by KOH lowers the likelihood of phytotoxic effects of Na, but K and Na have similar effects on disaggregation. PMID:22707204

  7. Markets for Clean Air

    NASA Astrophysics Data System (ADS)

    Ellerman, A. Denny; Joskow, Paul L.; Schmalensee, Richard; Montero, Juan-Pablo; Bailey, Elizabeth M.

    2000-06-01

    Markets for Clean Air provides a comprehensive, in-depth description and evaluation of the first three years' experience with the U.S. Acid Rain Program. This environmental control program is the world's first large-scale use of a tradable emission permit system for achieving environmental goals. The book analyzes the behavior and performance of the market for emissions permits, called allowances in the Acid Rain Program, and quantifies emission reductions, compliance costs, and cost savings associated with the trading program. The book also includes chapters on the historical context in which this pioneering program developed and the political economy of allowance allocations.

  8. Intramolecular deactivation processes in complexes of salicylic acid or glycolic acid with Eu(III)

    NASA Astrophysics Data System (ADS)

    Kuke, S.; Marmodée, B.; Eidner, S.; Schilde, U.; Kumke, M. U.

    2010-04-01

    The complexation of Eu(III) by 2-hydroxy benzoic acid (2HB) or glycolic acid (GL) was investigated using steady-state and time-resolved laser spectroscopy. Experiments were carried out in H 2O as well as in D 2O in the temperature range of 80Kprocesses (other than OH quenching induced by water molecules) need to be determined and considered in detail, in order to extract speciation-relevant information from luminescence data (e.g., estimation of the number of water molecules nO in the first coordination sphere of Eu(III)). In case of 2HB, conclusions drawn from the evaluation of the Eu(III) luminescence are compared with results of a X-ray structure analysis.

  9. Contact cleaning of polymer film solar reflectors

    NASA Astrophysics Data System (ADS)

    Sansom, Christopher; Fernández-García, Aránzazu; Sutter, Florian; Almond, Heather; King, Peter

    2016-05-01

    This paper describes the accelerated ageing of polymer film reflecting surfaces under the conditions to be found during contact cleaning of Concentrating Solar Power (CSP) collectors in the presence of dust and sand particles. In these situations, contact cleaning using brushes and water is required to clean the reflecting surfaces. Whilst suitable for glass reflectors, this paper discusses the effects of existing cleaning processes on the optical and visual properties of polymer film surfaces, and then describes the development of a more benign but effective contact cleaning process for cleaning polymer reflectors. The effects of a range of cleaning brushes are discussed, with and without the presence of water, in the presence of sand and dust particles from selected representative locations. Reflectance measurements and visual inspection shows that a soft cleaning brush with a small amount of water can clean polymer film reflecting surfaces without inflicting surface damage or reducing specular reflectance.

  10. Development of Acetic Acid Removal Technology for the UREX+Process

    SciTech Connect

    Robert M. Counce; Jack S. Watson

    2009-06-30

    It is imperative that acetic acid is removed from a waste stream in the UREX+process so that nitric acid can be recycled and possible interference with downstreatm steps can be avoidec. Acetic acid arises from acetohydrozamic acid (AHA), and is used to suppress plutonium in the first step of the UREX+process. Later, it is hydrolyzed into hydroxyl amine nitrate and acetic acid. Many common separation technologies were examined, and solvent extraction was determined to be the best choice under process conditions. Solvents already used in the UREX+ process were then tested to determine if they would be sufficient for the removal of acetic acid. The tributyl phosphage (TBP)-dodecane diluent, used in both UREX and NPEX, was determined to be a solvent system that gave sufficient distribution coefficients for acetic acid in addition to a high separation factor from nitric acid.

  11. Healy clean coal project

    SciTech Connect

    Not Available

    1992-03-01

    The objective of the Healy Clean Coal Project is to demonstrate the integration of an advanced combustor and a heat recovery system with both high and low temperature emission control processes. Resulting emission levels of SO{sub 2}, NO{sub x}, and particulates are expected to be significantly better than the federal New Source Performance Standards. (VC)

  12. Healy clean coal project

    SciTech Connect

    Not Available

    1992-05-01

    The objective of the Healy Clean Coal Project is to demonstrate the integration of an advanced combustor and heat recovery system with both high and low temperature emission control processes. The emission levels of SO{sub 2}, NO{sub x}, and particulates are expected to be significantly better then the federal New Source Performance Standards. (VC)

  13. Development of OTM Syngas Process and Testing of Syngas Derived Ultra-clean Fuels in Diesel Engines and Fuel Cells

    SciTech Connect

    E.T. Robinson; John Sirman; Prasad Apte; Xingun Gui; Tytus R. Bulicz; Dan Corgard; John Hemmings

    2005-05-01

    This final report summarizes work accomplished in the Program from January 1, 2001 through December 31, 2004. Most of the key technical objectives for this program were achieved. A breakthrough material system has lead to the development of an OTM (oxygen transport membrane) compact planar reactor design capable of producing either syngas or hydrogen. The planar reactor shows significant advantages in thermal efficiency and a step change reduction in costs compared to either autothermal reforming or steam methane reforming with CO{sub 2} recovery. Syngas derived ultra-clean transportation fuels were tested in the Nuvera fuel cell modular pressurized reactor and in International Truck and Engine single cylinder test engines. The studies compared emission and engine performance of conventional base fuels to various formulations of ultra-clean gasoline or diesel fuels. A proprietary BP oxygenate showed significant advantage in both applications for reducing emissions with minimal impact on performance. In addition, a study to evaluate new fuel formulations for an HCCI engine was completed.

  14. Clean coal today

    SciTech Connect

    1990-01-01

    This is the first issue of the Clean Coal Today publication. Each issue will provide project status reports, feature articles about certain projects and highlight key events concerning the US Clean Coal Technology Demonstration Program. Projects described in this publication include: Colorado-Ute Electric Association Circulating Fluidized Bed Combustor Project at Nucla, Colorado; Babcock and Wilcox coolside and limestone injection multistage burner process (dry sorbent injection); Coal Tech's Advanced Cyclone Combustor Project; and the TIDD pressurized fluidized bed combustor combined cycle facility in Brilliant, Ohio. The status of other projects is included.

  15. Dynamics of the anaerobic process: effects of volatile fatty acids.

    PubMed

    Pind, Peter F; Angelidaki, Irini; Ahring, Birgitte K

    2003-06-30

    A complex and fast dynamic response of the anaerobic biogas system was observed when the system was subjected to pulses of volatile fatty acids (VFAs). It was shown that a pulse of specific VFAs into a well-functioning continuous stirred tank reactor (CSTR) system operating on cow manure affected both CH(4) yield, pH, and gas production and that a unique reaction pattern was seen for the higher VFAs as a result of these pulses. In this study, two thermophilic laboratory reactors were equipped with a novel VFA-sensor for monitoring specific VFAs online. Pulses of VFAs were shown to have a positive effect on process yield and the levels of all VFA were shown to stabilize at a lower level after the biomass had been subjected to several pulses. The response to pulses of propionate or acetate was different from the response to butyrate, iso-butyrate, valerate, or iso-valerate. High concentrations of propionate affected the degradation of all VFAs, while a pulse of acetate affected primarily the degradation of iso-valerate or 2-methylbutyrate. Pulses of n-butyrate, iso-butyrate, and iso-valerate yielded only acetate, while degradation of n-valerate gave both propionate and acetate. Product sensitivity or inhibition was shown for the degradation of all VFAs tested. Based on the results, it was concluded that measurements of all specific VFAs are important for control purposes and increase and decrease in a specific VFA should always be evaluated in close relationship to the conversion of other VFAs and the history of the reactor process. It should be pointed out that the observed dynamics of VFA responses were based on hourly measurements, meaning that the response duration was much lower than the hydraulic retention time, which exceeds several days in anaerobic CSTR systems. PMID:12701145

  16. Effect of fatty acids on energy coupling processes in mitochondria.

    PubMed

    Wojtczak, L; Schönfeld, P

    1993-11-01

    Long-chain fatty acids are natural uncouplers of oxidative phosphorylation in mitochondria. The protonophoric mechanism of this action is due to transbilayer movement of undissociated fatty acid in one direction and the passage of its anion in the opposite direction. The transfer of the dissociated form of fatty acid can be, at least in some kinds of mitochondrion, facilitated by adenine nucleotide translocase. Apart from dissipating the electrochemical proton gradient, long-chain fatty acids decrease the activity of the respiratory chain by mechanism(s) not fully understood. In intact cells and tissues fatty acids operate mostly as excellent respiratory substrates, providing electrons to the respiratory chain. This function masks their potential uncoupling effect which becomes apparent only under special physiological or pathological conditions characterized by unusual fatty acid accumulation. Short- and medium-chain fatty acids do not have protonophoric properties. Nevertheless, they contribute to energy dissipation because of slow intramitochondrial hydrolysis of their activation products, acyl-AMP and acyl-CoA. Long-chain fatty acids increase permeability of mitochondrial membranes to alkali metal cations. This is due to their ionophoric mechanism of action. Regulatory function of fatty acids with respect to specific cation channels has been postulated for the plasma membrane of muscle cells, but not demonstrated in mitochondria. Under cold stress, cold acclimation and arousal from hibernation the uncoupling effect of fatty acids may contribute to increased thermogenesis, especially in the muscle tissue. In brown adipose tissue, the special thermogenic organ of mammals, long-chain fatty acids promote operation of the unique natural uncoupling protein, thermogenin. As anionic amphiphiles, long-chain fatty acids increase the negative surface charge of biomembranes, thus interfering in their enzymic and transporting functions. PMID:8399375

  17. Aqueous cleaning design presentation

    NASA Technical Reports Server (NTRS)

    Maltby, Peter F.

    1995-01-01

    The phase-out of CFC's and other ozone depleting chemicals has prompted industries to re-evaluate their present methods of cleaning. It has become necessary to find effective substitutes for their processes as well as to meet the new cleaning challenges of improved levels of cleanliness and to satisfy concerns about environmental impact of any alternative selected. One of the most popular alternatives being selected is aqueous cleaning. This method offers an alternative for removal of flux, grease/oil, buffing compound, particulates and other soils while minimizing environmental impact. What I will show are methods that can be employed in an aqueous cleaning system that will make it environmentally friendly, relatively simple to maintain and capable of yielding an even higher quality of cleanliness than previously obtained. I will also explore several drying techniques available for these systems and other alternatives along with recent improvements made in this technology. When considering any type of cleaning system, a number of variables should be determined before selecting the basic configuration. Some of these variables are: (1) Soil or contaminants being removed from your parts; (2) The level of cleanliness required; (3) The environmental considerations of your area; (4) Maintenance requirements; and (5) Operating costs.

  18. New Tools for Cost-Effective Restroom Cleaning.

    ERIC Educational Resources Information Center

    Bigger, Alan; Bigger, Linda

    2002-01-01

    Reviews labor-saving innovations and processes in restroom cleaning, including cleaning kits, vapor cleaning technology, and pressure washer/squeegee/vacuuming systems. Also includes a sidebar on choosing better mop equipment. (EV)

  19. Stable carbon isotopic compositions of low-molecular-weight dicarboxylic acids, oxocarboxylic acids, α-dicarbonyls, and fatty acids: implications for atmospheric processing of organic aerosols

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Kawamura, K.; Cao, F.; Lee, M.

    2015-12-01

    Stable carbon isotopic compositions (δ13C) were measured for 23 individual organic species including 9 dicarboxylic acids, 7 oxocarboxylic acids, 1 tricarboxylic acid, 2 α-dicarbonyls and 4 fatty acids in the aerosols from Gosan background site in East Asia. δ13C of particle-phase glyoxal and methylglyoxal are significantly higher than those previously reported for isoprene and other precursors, associated with isotope fractionation during atmospheric oxidation. 13C is consistently more enriched for oxalic acid (C2), glyoxylic acid, pyruvic acid, glyoxal and methylglyoxal compared to other organic compounds identified, which can be explained by the kinetic isotope effects during aqueous-phase processing and the subsequent gas-particle partitioning after clouds or wet aerosols evaporation δ13C of C2 is positively correlated with C2 and organic carbon ratio, indicating that a photochemical production of C2 is more pronounced than its degradation process during long-range transport. The 13C results also suggest that aqueous-phase oxidation of glyoxal and methylglyoxal is major formation process of oxalic acid production via the major intermediates glyoxylic acid and pyruvic acid. This study provides evidence that organic aerosols are intensively photo-chemically aged in this region.

  20. New fermentation processes for producing itaconic acid and citric acid for industrial uses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Itaconic acid is an important industrial chemical that we have produced by fermentation of simple sugars using the yeast Pseudozyma antarctica. Itaconic acid is priced at ~$4 per kg and has an annual market volume of about 15,000 metric tons. Itaconic acid is used in the polymer industry and for m...

  1. Process for immobilizing radioactive boric acid liquid wastes

    SciTech Connect

    Greenhalgh, W.O.

    1986-06-17

    A method is described for immobilizing radioactive boric acid waste solutions comprising: neutralizing a boric acid waste solution containing radionuclides with calcium hydroxide and forming a precipitate, evaporating the precipitate to near dryness, and firing the dry precipitate to form a calcium borate glass product containing the radionuclides.

  2. Water-enhanced solubility of carboxylic acids in organic solvents and its applications to extraction processes

    SciTech Connect

    Starr, J.N.; King, C.J.

    1991-11-01

    The solubilities of carboxylic acids in certain organic solvents increase remarkably with an increasing amount of water in the organic phase. This phenomenon leads to a novel extract regeneration process in which the co-extracted water is selectively removed from an extract, and the carboxylic acid precipitates. This approach is potentially advantageous compared to other regeneration processes because it removes a minor component of the extract in order to achieve a large recovery of acid from the extract. Carboxylic acids of interest include adipic acid, fumaric acid, and succinic acid because of their low to moderate solubilities in organic solvents. Solvents were screened for an increase in acid solubility with increased water concentration in the organic phase. Most Lewis-base solvents were found to exhibit this increased solubility phenomena. Solvents that have a carbonyl functional group showed a very large increase in acid solubility. 71 refs., 52 figs., 38 tabs.

  3. Demonstration of Innovative Applications of Technology for the CT-121 FGD Process. Project Performance Summary, Clean Coal Technology Demonstration Project

    SciTech Connect

    None, None

    2002-08-01

    This project is part of the U.S. Department of Energy's (DOE) Clean Coal Technology Demonstration Program (CCTDP) established to address energy and environmental concerns related to coal use. DOE sought cost-shared partnerships with industry through five nationally competed solicitations to accelerate commercialization of the most promising advanced coal-based power generation and pollution control technologies. The CCTDP, valued at over five billion dollars, has significantly leveraged federal funding by forging effective partnerships founded on sound principles. For every federal dollar invested, CCTDP participants have invested two dollars. These participants include utilities, technology developers, state governments, and research organizations. The project presented here was one of sixteen selected from 55 proposals submitted in 1988 and 1989 in response to the CCTDP second solicitation.

  4. Evaluation of a solid-phase extraction dual-layer carbon/primary secondary amine for clean-up of fatty acid matrix components from food extracts in multiresidue pesticide analysis.

    PubMed

    Shimelis, Olga; Yang, Yuhui; Stenerson, Katherine; Kaneko, Toshiro; Ye, Michael

    2007-09-21

    The use of dual-layer solid-phase extraction (SPE), a primary-secondary amine (PSA) in combination with graphitized carbon black (GCB), was evaluated for sample clean-up during multiresidue pesticide screening of agricultural and food products. The retention of fatty acids by the PSA sorbent was quantified and the effect of the elution solvent on the retention of fatty acid on the SPE cartridge was evaluated. The use of stronger elution solvents to elute certain pesticides from graphitized carbon was shown to interfere with the capacity of PSA to bind fatty acids. A suitable protocol was tested using GCB/PSA dual-layer SPE to clean-up several food matrices and to simultaneously screen multiple fortified pesticides with a wide range of physico-chemical properties. With a few exceptions, pesticide recoveries were between 85% and 110%, and sample-to-sample differences of less than 5% were achieved, demonstrating the versatile suitability of the dual-layer SPE to sample clean-up. PMID:17689545

  5. Modeling of the acid-leaching process in the preparation of chemical ultraclean coal

    SciTech Connect

    Wang, H.; Wang, Z.

    1995-12-31

    The paper is continued from ``Modeling of the Preparation of Chemical Ultraclean Coal`` presented at 11th Pittsburgh Coal Conference. As to acid-alkali deashing process, acid-leaching is a post-processing for the preparation of ultraclean coal, which can be used to remove chemical products caused by alkali-leaching processing. A soluble model is developed to establish an acid-leaching rate equation, which indicates that model result is compatible well with the experimental data.

  6. Clean coal technology: The new coal era

    SciTech Connect

    Not Available

    1994-01-01

    The Clean Coal Technology Program is a government and industry cofunded effort to demonstrate a new generation of innovative coal processes in a series of full-scale showcase`` facilities built across the country. Begun in 1986 and expanded in 1987, the program is expected to finance more than $6.8 billion of projects. Nearly two-thirds of the funding will come from the private sector, well above the 50 percent industry co-funding expected when the program began. The original recommendation for a multi-billion dollar clean coal demonstration program came from the US and Canadian Special Envoys on Acid Rain. In January 1986, Special Envoys Lewis and Davis presented their recommendations. Included was the call for a 5-year, $5-billion program in the US to demonstrate, at commercial scale, innovative clean coal technologies that were beginning to emerge from research programs both in the US and elsewhere in the world. As the Envoys said: if the menu of control options was expanded, and if the new options were significantly cheaper, yet highly efficient, it would be easier to formulate an acid rain control plan that would have broader public appeal.

  7. DEVELOPMENT OF HAZARDOUS SLUDGE SIMULANTS FOR ENHANCED CHEMICAL CLEANING TESTS

    SciTech Connect

    Eibling, R.

    2010-04-12

    An Enhanced Chemical Cleaning (ECC) process is being developed by Savannah River Remediation (SRR) to aid in Savannah River Site (SRS) High-Level Waste (HLW) tank closure. After bulk waste removal, the ECC process can be used to dissolve and remove much of the remaining sludge from HLW tanks. The ECC process uses dilute oxalic acid (1 wt %) with in-line pH monitoring and control. The resulting oxalate is decomposed through hydroxylation using an Advanced Oxidation Process (AOP). Minimizing the amount of oxalic acid used for dissolution and the subsequent oxidative destruction of oxalic acid will minimize the potential for downstream impacts. Initial efficacy tests by AREVA demonstrated that previous tank heel simulants could be dissolved using dilute oxalic acid. The oxalate could be decomposed by an AOP that utilized ozone and ultraviolet (UV) light, and the resultant metal oxides and hydroxides could be separated out of the process.

  8. Alternate cleaning methods for LCCAs. Final report

    SciTech Connect

    Adams, B.E.

    1993-04-01

    The purpose of this project was to evaluate DI water followed by isopropyl alcohol (IPA) cleaning and no cleaning of leadless chip carriers (LCCs). Both environmentally safe methods were to be tested against the current chlorofluorocarbon (CFC) material cleaning baseline. Several experiments were run to compare production and electrical yields of LCCs cleaned by all three methods. The critical process steps most affected by cleaning were wire bonding, sealing, particle induced noise detection (PIND), moisture content, and electrical. Yields for the experimental lots cleaned by CFC, DI water plus IPA, and no cleaning were 56%, 72%, and 75%, respectively. The overall results indicated that vapor degreasing/ultrasonic cleaning in CFCs could be replaced by the aqueous method. No cleaning could also be considered if an effective dry method of particle removal could be developed.

  9. An integrated bioconversion process for the production of L-lactic acid from starchy feedstocks

    SciTech Connect

    Tsai, S.P.; Moon, S.H.

    1997-07-01

    The potential market for lactic acid as the feedstock for biodegradable polymers, oxygenated chemicals, and specialty chemicals is significant. L-lactic acid is often the desired enantiomer for such applications. However, stereospecific lactobacilli do not metabolize starch efficiently. In this work, Argonne researchers have developed a process to convert starchy feedstocks into L-lactic acid. The processing steps include starch recovery, continuous liquefaction, and simultaneous saccharification and fermentation. Over 100 g/L of lactic acid was produced in less than 48 h. The optical purity of the product was greater than 95%. This process has potential economical advantages over the conventional process.

  10. Research of laser cleaning technology for steam generator tubing

    NASA Astrophysics Data System (ADS)

    Hou, Suixa; Luo, Jijun; Xu, Jun; Yuan, Bo

    2010-10-01

    Surface cleaning based on the laser-induced breakdown of gas and subsequent shock wave generation can remove small particles from solid surfaces. Accordingly, several studies in steam generator tubes of nuclear power plants were performed to expand the cleaning capability of the process. In this work, experimental apparatus of laser cleaning was designed in order to clean heat tubes in steam generator. The laser cleaning process is monitored by analyzing acoustic emission signal experimentally. Experiments demonstrate that laser cleaning can remove smaller particles from the surface of steam generator tubes better than other cleaning process. It has advantages in saving on much manpower and material resource, and it is a good cleaning method for heat tubes, which can be real-time monitoring in laser cleaning process of heat tubes by AE signal. As a green cleaning process, laser cleaning technology in equipment maintenance will be a good prospect.

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

    NASA Astrophysics Data System (ADS)

    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

  12. Fermentation and recovery process for lactic acid production

    DOEpatents

    Tsai, S.P.; Moon, S.H.; Coleman, R.

    1995-11-07

    A method is described for converting starch to glucose and fermenting glucose to lactic acid, including simultaneous saccharification and fermentation through use of a novel consortium of bacterial strains. 2 figs.

  13. Stable carbon isotopic compositions of low-molecular-weight dicarboxylic acids, oxocarboxylic acids, α-dicarbonyls, and fatty acids: Implications for atmospheric processing of organic aerosols

    NASA Astrophysics Data System (ADS)

    Zhang, Yan-Lin; Kawamura, Kimitaka; Cao, Fang; Lee, Meehye

    2016-04-01

    Stable carbon isotopic compositions (δ13C) were measured for 23 individual organic species including 9 dicarboxylic acids, 7 oxocarboxylic acids, 1 tricarboxylic acid, 2 α-dicarbonyls, and 4 fatty acids in the aerosols from Gosan background site in East Asia. δ13C values of particle phase glyoxal and methylglyoxal are significantly larger than those previously reported for isoprene and other precursors. The values are consistently less negative in oxalic acid (C2, average -14.1‰), glyoxylic acid (-13.8‰), pyruvic acid (-19.4‰), glyoxal (-13.5‰), and methylglyoxal (-18.6‰) compared to other organic species (e.g., palmitic acid, -26.3‰), which can be explained by the kinetic isotope effects during atmospheric oxidation of pre-aged precursors (e.g., isoprene) and the subsequent gas-particle partitioning after the evaporation of clouds or wet aerosols. The δ13C values of C2 is positively correlated with C2 to organic carbon ratio, indicating that photochemical production of C2 is more pronounced than its degradation during long-range atmospheric transport. The isotopic results also suggest that aqueous phase oxidation of glyoxal and methylglyoxal is a major formation process of oxalic acid via the intermediates such as glyoxylic acid and pyruvic acid. This study provides evidence that organic aerosols are intensively photochemically aged in the western North Pacific rim.

  14. PROCESS FOR RECOVERING URANIUM FROM AQUEOUS PHOSPHORIC ACID LIQUORS

    DOEpatents

    Schmitt, J.M.

    1962-09-01

    A liquid-liquid extraction method is given for recovering uranium values from aqueous solutions. An acidic aqueous solution containing uranium values is contacted with an organic phase comprising an organic diluent and the reaction product of phosphorous pentoxide and a substantially pure dialkylphosphoric acid. The uranium values are transferred to the organic phase even from aqueous solutions containing a high concentration of strong uranium complexing agents such as phosphate ions. (AEC)

  15. Process for chemical reaction of amino acids and amides yielding selective conversion products

    DOEpatents

    Holladay, Jonathan E.

    2006-05-23

    The invention relates to processes for converting amino acids and amides to desirable conversion products including pyrrolidines, pyrrolidinones, and other N-substituted products. L-glutamic acid and L-pyroglutamic acid provide general reaction pathways to numerous and valuable selective conversion products with varied potential industrial uses.

  16. A solvent extraction approach to recover acetic acid from mixed waste acids produced during semiconductor wafer process.

    PubMed

    Shin, Chang-Hoon; Kim, Ju-Yup; Kim, Jun-Young; Kim, Hyun-Sang; Lee, Hyang-Sook; Mohapatra, Debasish; Ahn, Jae-Woo; Ahn, Jong-Gwan; Bae, Wookeun

    2009-03-15

    Recovery of acetic acid (HAc) from the waste etching solution discharged from silicon wafer manufacturing process has been attempted by using solvent extraction process. For this purpose 2-ethylhexyl alcohol (EHA) was used as organic solvent. In the pre-treatment stage >99% silicon and hydrofluoric acid was removed from the solution by precipitation. The synthesized product, Na(2)SiF(6) having 98.2% purity was considered of commercial grade having good market value. The waste solution containing 279 g/L acetic acid, 513 g/L nitric acid, 0.9 g/L hydrofluoric acid and 0.030 g/L silicon was used for solvent extraction study. From the batch test results equilibrium conditions for HAc recovery were optimized and found to be 4 stages of extraction at an organic:aqueous (O:A) ratio of 3, 4 stages of scrubbing and 4 stages of stripping at an O:A ratio of 1. Deionized water (DW) was used as stripping agent to elute HAc from organic phase. In the whole batch process 96.3% acetic acid recovery was achieved. Continuous operations were successfully conducted for 100 h using a mixer-settler to examine the feasibility of the extraction system for its possible commercial application. Finally, a complete process flowsheet with material balance for the separation and recovery of HAc has been proposed. PMID:18639982

  17. Valuation of OSA process and folic acid addition as excess sludge minimization alternatives applied in the activated sludge process.

    PubMed

    Martins, C L; Velho, V F; Ramos, S R A; Pires, A S C D; Duarte, E C N F A; Costa, R H R

    2016-01-01

    The aim of this study was to investigate the ability of the oxic-settling-anaerobic (OSA)-process and the folic acid addition applied in the activated sludge process to reduce the excess sludge production. The study was monitored during two distinct periods: activated sludge system with OSA-process, and activated sludge system with folic acid addition. The observed sludge yields (Yobs) were 0.30 and 0.08 kgTSS kg(-1) chemical oxygen demand (COD), control phase and OSA-process (period 1); 0.33 and 0.18 kgTSS kg(-1) COD, control phase and folic acid addition (period 2). The Yobs decreased by 73 and 45% in phases with the OSA-process and folic acid addition, respectively, compared with the control phases. The sludge minimization alternatives result in a decrease in excess sludge production, without negatively affecting the performance of the effluent treatment. PMID:26901714

  18. Machine Cleans And Degreases Without Toxic Solvents

    NASA Technical Reports Server (NTRS)

    Gurguis, Kamal S.; Higginson, Gregory A.

    1993-01-01

    Appliance uses hot water and biodegradable chemicals to degrease and clean hardware. Spray chamber essentially industrial-scale dishwasher. Front door tilts open, and hardware to be cleaned placed on basket-like tray. During cleaning process, basket-like tray rotates as high-pressure "V" jets deliver steam, hot water, detergent solution, and rust inhibitor as required.

  19. EVALUATION OF PHYSICAL/CHEMICAL COAL CLEANING AND FLUE GAS DESULFURIZATION

    EPA Science Inventory

    The report gives results of evaluations of physical coal cleaning (PCC), chemical coal cleaning (CCC), and coal cleaning combined with flue gas desulfurization (FGD). It includes process descriptions, cleaning performances, comparative capital investments, and annual revenue requ...

  20. Process for the obtainment of boric acid from colemanite and/or howlite minerals

    SciTech Connect

    Polendo-Loredo, J.

    1988-07-12

    A process for obtaining boric acid from colemanite minerals, howlite minerals, or mixtures thereof is described comprising: treating the mineral with sulfuric acid to dissolve boron compounds; separating the solution thus formed from the insoluble solids in suspension; reacting the solution with hydrogen sulfide to precipitate arsenic and iron impurities; separating the impurities precipitated from the remaining solution; cooling the remaining solution to precipitate boric acid; and separating the boric acid from the remaining solution.

  1. Self-cleaning Metal Organic Framework (MOF) based ultra filtration membranes--a solution to bio-fouling in membrane separation processes.

    PubMed

    Prince, J A; Bhuvana, S; Anbharasi, V; Ayyanar, N; Boodhoo, K V K; Singh, G

    2014-01-01

    Bio-fouling is a serious problem in many membrane-based separation processes for water and wastewater treatment. Current state of the art methods to overcome this are to modify the membranes with either hydrophilic additives or with an antibacterial compound. In this study, we propose and practise a novel concept to prevent bio-fouling by developing a killing and self-cleaning membrane surface incorporating antibacterial silver nanoparticles and highly hydrophilic negatively charged carboxylic and amine functional groups. The innovative surface chemistry helps to reduce the contact angle of the novel membrane by at least a 48% and increase the pure water flux by 39.4% compared to the control membrane. The flux drop for the novel membrane is also lower (16.3% of the initial flux) than the control membrane (55.3% of the initial flux) during the long term experiments with protein solution. Moreover, the novel membrane continues to exhibit inhibition to microbes even after 1320 min of protein filtration. Synthesis of self-cleaning ultrafiltration membrane with long lasting properties opens up a viable solution for bio-fouling in ultrafiltration application for wastewater purification. PMID:25296745

  2. Self-cleaning Metal Organic Framework (MOF) based ultra filtration membranes - A solution to bio-fouling in membrane separation processes

    PubMed Central

    Prince, J. A.; Bhuvana, S.; Anbharasi, V.; Ayyanar, N.; Boodhoo, K. V. K.; Singh, G.

    2014-01-01

    Bio-fouling is a serious problem in many membrane-based separation processes for water and wastewater treatment. Current state of the art methods to overcome this are to modify the membranes with either hydrophilic additives or with an antibacterial compound. In this study, we propose and practise a novel concept to prevent bio-fouling by developing a killing and self-cleaning membrane surface incorporating antibacterial silver nanoparticles and highly hydrophilic negatively charged carboxylic and amine functional groups. The innovative surface chemistry helps to reduce the contact angle of the novel membrane by at least a 48% and increase the pure water flux by 39.4% compared to the control membrane. The flux drop for the novel membrane is also lower (16.3% of the initial flux) than the control membrane (55.3% of the initial flux) during the long term experiments with protein solution. Moreover, the novel membrane continues to exhibit inhibition to microbes even after 1320 min of protein filtration. Synthesis of self-cleaning ultrafiltration membrane with long lasting properties opens up a viable solution for bio-fouling in ultrafiltration application for wastewater purification. PMID:25296745

  3. Self-cleaning Metal Organic Framework (MOF) based ultra filtration membranes - A solution to bio-fouling in membrane separation processes

    NASA Astrophysics Data System (ADS)

    Prince, J. A.; Bhuvana, S.; Anbharasi, V.; Ayyanar, N.; Boodhoo, K. V. K.; Singh, G.

    2014-10-01

    Bio-fouling is a serious problem in many membrane-based separation processes for water and wastewater treatment. Current state of the art methods to overcome this are to modify the membranes with either hydrophilic additives or with an antibacterial compound. In this study, we propose and practise a novel concept to prevent bio-fouling by developing a killing and self-cleaning membrane surface incorporating antibacterial silver nanoparticles and highly hydrophilic negatively charged carboxylic and amine functional groups. The innovative surface chemistry helps to reduce the contact angle of the novel membrane by at least a 48% and increase the pure water flux by 39.4% compared to the control membrane. The flux drop for the novel membrane is also lower (16.3% of the initial flux) than the control membrane (55.3% of the initial flux) during the long term experiments with protein solution. Moreover, the novel membrane continues to exhibit inhibition to microbes even after 1320 min of protein filtration. Synthesis of self-cleaning ultrafiltration membrane with long lasting properties opens up a viable solution for bio-fouling in ultrafiltration application for wastewater purification.

  4. Precision Cleaning - Path to Premier

    NASA Technical Reports Server (NTRS)

    Mackler, Scott E.

    2008-01-01

    ITT Space Systems Division s new Precision Cleaning facility provides critical cleaning and packaging of aerospace flight hardware and optical payloads to meet customer performance requirements. The Precision Cleaning Path to Premier Project was a 2007 capital project and is a key element in the approved Premier Resource Management - Integrated Supply Chain Footprint Optimization Project. Formerly precision cleaning was located offsite in a leased building. A new facility equipped with modern precision cleaning equipment including advanced process analytical technology and improved capabilities was designed and built after outsourcing solutions were investigated and found lacking in ability to meet quality specifications and schedule needs. SSD cleans parts that can range in size from a single threaded fastener all the way up to large composite structures. Materials that can be processed include optics, composites, metals and various high performance coatings. We are required to provide verification to our customers that we have met their particulate and molecular cleanliness requirements and we have that analytical capability in this new facility. The new facility footprint is approximately half the size of the former leased operation and provides double the amount of throughput. Process improvements and new cleaning equipment are projected to increase 1st pass yield from 78% to 98% avoiding $300K+/yr in rework costs. Cost avoidance of $350K/yr will result from elimination of rent, IT services, transportation, and decreased utility costs. Savings due to reduced staff expected to net $4-500K/yr.

  5. Process for the preparation of 3,4-dihydroxybutanoic acid and salts thereof

    DOEpatents

    Hollingsworth, Rawle I.

    1994-01-01

    A process for the preparation of 3,4-dihydroxybutanoic acid (1) and salts thereof from a glucose source containing 1,4-linked glucose as a substituent is described. The process uses an alkali metal hdyroxide and hydrogen peroxide to convert the glucose source to (1). The compound (1) is useful as a chemical intermediate to naturally occurring fatty acids and is used to prepare 3,4-dihydroxybutanoic acid-gamma-lactone (2) and furanone (3), particularly stereoisomers of these compounds.

  6. Process For The Preparation Of 3,4-Dihyd Roxybutanoic Acid And Salts Thereof

    DOEpatents

    Hollingsworth, Rawle I.

    1994-06-07

    A process for the preparation of 3,4-dihydroxybutanoic acid (1) and salts thereof from a glucose source containing 1,4-linked glucose as a substituent is described. The process uses an alkali metal hdyroxide and hydrogen peroxide to convert the glucose source to (1). The compound (1) is useful as a chemical intermediate to naturally occurring fatty acids and is used to prepare 3,4-dihydroxybutanoic acid-gamma-lactone (2) and furanone (3), particularly stereoisomers of these compounds.

  7. Process for immobilizing radioactive boric acid liquid wastes

    SciTech Connect

    Greenhalgh, Wilbur O.

    1986-01-01

    A method of immobilizing boric acid liquid wastes containing radionuclides by neutralizing the solution and evaporating the resulting precipitate to near dryness. The dry residue is then fused into a reduced volume, insoluble, inert, solid form containing substantially all the radionuclides.

  8. ACID RAIN MITAGATION STUDY. VOLUME III: INDUSTRIAL BOILERS AND PROCESSES

    EPA Science Inventory

    The report gives results of a 4-month study of existing industrial sources of SO2 emissions in the Acid Rain Mitigation Study (ARMS) region, including all the states east of the Mississippi River, as well as MN, IA, MO, AR, LA, ND, SD, NE, KS, OK, and TX. Study aims were to: (1) ...

  9. Alternative Enhanced Chemical Cleaning Basic Studies Results FY09

    SciTech Connect

    Hay, M.; King, W.

    2010-05-05

    Due to the need to close waste storage tanks, chemical cleaning methods are needed for the effective removal of the heels. Oxalic acid is the preferred cleaning reagent for sludge heel dissolution, particularly for iron-based sludge, due to the strong complexing strength of the oxalate. However, the large quantity of oxalate added to the tank farm from oxalic acid based chemical cleaning has significant downstream impacts. Optimization of the oxalic acid cleaning process can potentially reduce the downstream impacts from chemical cleaning. To optimize oxalic acid usage, a detailed understanding of the chemistry of oxalic acid based sludge dissolution is required. Additionally, other acid systems may be required for specific waste components with low solubility in oxalic acid and as a means to reduce oxalic acid usage in general. Solubility tests were conducted using non-radioactive, pure metal phases known to be the primary phases present in High Level Waste sludge. The metal phases studied included the aluminum phases gibbsite and boehmite and the iron phases magnetite and hematite. Hematite and boehmite are expected to be the most difficult iron and aluminum phases to dissolve. These mineral phases have been identified in both SRS and Hanford High Level Waste sludge. Acids evaluated for dissolution included oxalic, nitric, and sulfuric acids. The results of the solubility tests indicate that oxalic and sulfuric acids are more effective for the dissolution of the primary sludge phases. For boehmite, elevated temperature will be required to promote effective phase dissolution in the acids studied. Literature reviews, thermodynamic modeling, and experimental results have all confirmed that pH control using a supplemental proton source (additional acid) is critical for minimization of oxalic acid usage during the dissolution of hematite. These results emphasize the importance of pH control in optimizing hematite dissolution in oxalic acid and may explain the somewhat

  10. Electron driven processes in chlorodifluoroacetic acid methyl ester

    NASA Astrophysics Data System (ADS)

    Kopyra, Janina

    2014-07-01

    Dissociative electron attachment to gas phase 2-chloro-2,2-difluoroacetic acid methyl ester (CClF2COOCH3) is studied by means of a crossed beams apparatus. Effective cleavage of the C-Cl bond is observed within a broad resonance in the energy range 0-1 eV and visible via the appearance of the light fragment Cl-. In chlorodifluoroacetic acid cleavage of the C-Cl bond was observed not only via the Cl- anion formation but predominantly via expulsion of the neutral chlorine atom leading to the formation of the (M-Cl)- anion. Similar to the previously studied esters CF3COOCH3 and CF3COOC2H5[I. Martin, J. Langer, E. Illenberger, Z. Phys. Chem. 222, 1185 (2008)], we observe reaction due to the cleavage of the ester bond resulting in the formation of the closed shell (M-CH3)- anion.

  11. A novel clean and effective syngas production system based on partial oxidation of methane assisted solid oxide co-electrolysis process

    NASA Astrophysics Data System (ADS)

    Wang, Yao; Liu, Tong; Fang, Shumin; Xiao, Guoliang; Wang, Huanting; Chen, Fanglin

    2015-03-01

    Development of the syngas production from solid oxide H2O/CO2 co-electrolysis is limited by the intensive energy input and low efficiency. Here, we present a new concept to efficiently generate syngas in both sides of the solid oxide electrolyzer by synergistically combining co-electrolysis with partial oxidation of methane (POM). Thermodynamic calculation and electrochemical measurements for the POM assisted solid oxide co-electrolysis processes on the SFM-SDC/LSGM/SFM-SDC cells exhibited an reduced electric input, increased energy conversion efficiency and decreased cathodic co-electrolysis polarization resistance in comparison with the conventional co-electrolysis. This method will be crucial to establish a clean and effective energy conversion system to meet global sustainable energy needs.

  12. The new Clean Air Act

    SciTech Connect

    Padmanabha, A.P. ); Olem, H. )

    1991-05-01

    This article is a title by title review of the new Clean Air Act and how it affects water quality and wastewater treatment. The bill provides for restoring and protecting lakes and rivers by reducing acid-rain-causing emissions and toxics from nonpoint-source runoff. Topics covered include urban smog, mobile sources, air toxics, acid rain, permits, ozone-depleting chemicals, enforcement, and the law's socio-economic impacts.

  13. Lactic acid as a decontaminant in slaughter and processing procedures.

    PubMed

    Snijders, J M; van Logtestijn, J G; Mossel, D A; Smulders, F J

    1985-10-01

    An attempt was made to interrelate the data obtained in experiments conducted by our Department along beef, veal and pig slaughter lines, using lactic acid (LA) for the decontamination of carcasses, cold and hot boned primal cuts, slaughter byproducts, and butcher's knives. First and foremost it was observed, that provided Good Manufacturing Practices are strictly followed, the microbial load of carcass surfaces will be substantially reduced. LA-decontamination may result in an additional reduction. Since in the early post-mortem period bacteria are not yet attached to the meat surface, LA-decontamination should preferably be applied to the hot carcass. It was demonstrated that, dependent on mode and duration of application, LA sprays not exceeding 1% v/v (beef), 1.25% v/v (veal) and 1.5% v/v (pork) resulted in acceptable carcass colour scores. Blood spots, which are particularly prone to discolouration by lactic acid application, should be removed at an early post-mortem stage e.g. by strong showering. The difference in surface pH between LA-treated and control carcasses disappeared within 72 hours post-mortem. Veal longissimus chops treated with LA solutions up to 2% v/v were not identified by a consumer taste panel as significantly different from controls. The 'immediate' bactericidal effect of LA-decontamination for beef, veal and pig carcasses, as well as for pig liver and veal brain, amounted to approximately 1.5 log cycles for the aerobic colony counts, strongly dependent on substrate and conditions of decontamination. In addition, a 'delayed' bacteriostatic effect was observed during storage, which is probably the result of a prolonged lag phase of acid-injured micro-organisms surviving lactic acid decontamination.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:4071948

  14. A novel cleaning process for industrial production of xylose in pilot scale from corncob by using screw-steam-explosive extruder.

    PubMed

    Zhang, Hong-Jia; Fan, Xiao-Guang; Qiu, Xue-Liang; Zhang, Qiu-Xiang; Wang, Wen-Ya; Li, Shuang-Xi; Deng, Li-Hong; Koffas, Mattheos A G; Wei, Dong-Sheng; Yuan, Qi-Peng

    2014-12-01

    Steam explosion is the most promising technology to replace conventional acid hydrolysis of lignocellulose for biomass pretreatment. In this paper, a new screw-steam-explosive extruder was designed and explored for xylose production and lignocellulose biorefinery at the pilot scale. We investigated the effect of different chemicals on xylose yield in the screw-steam-explosive extrusion process, and the xylose production process was optimized as followings: After pre-impregnation with sulfuric acid at 80 °C for 3 h, corncob was treated at 1.55 MPa with 9 mg sulfuric acid/g dry corncob (DC) for 5.5 min, followed by countercurrent extraction (3 recycles), decoloration (activated carbon dosage 0.07 g/g sugar, 75 °C for 40 min), and ion exchange (2 batches). Using this process, 3.575 kg of crystal xylose was produced from 22 kg corncob, almost 90 % of hemicellulose was released as monomeric sugar, and only a small amount of by-products was released (formic acid, acetic acid, fural, 5-hydroxymethylfurfural, and phenolic compounds were 0.17, 1.14, 0.53, 0.19, and 1.75 g/100 g DC, respectively). All results indicated that the screw-steam-explosive extrusion provides a more effective way to convert hemicellulose into xylose and could be an alternative method to traditional sulfuric acid hydrolysis process for lignocellulose biorefinery. PMID:24890135

  15. Raman Scattering Sensor for Control of the Acid Alkylation Process in Gasoline Production

    SciTech Connect

    Uibel, Rory, H.; Smith, Lee M.; Benner, Robert, E.

    2006-04-19

    Gasoline refineries utilize a process called acid alkylation to increase the octane rating of blended gasoline, and this is the single most expensive process in the refinery. For process efficiency and safety reasons, the sulfuric acid can only be used while it is in the concentration range of 98 to 86 %. The conventional technique to monitor the acid concentration is time consuming and is typically conducted only a few times per day. This results in running higher acid concentrations than they would like to ensure that the process proceeds uninterrupted. Maintaining an excessively high acid concentration costs the refineries millions of dollars each year. Using SBIR funding, Process Instruments Inc. has developed an inline sensor for real time monitoring of acid concentrations in gasoline refinery alkylation units. Real time data was then collected over time from the instrument and its responses were matched up with the laboratory analysis. A model was then developed to correlate the laboratory acid values to the Raman signal that is transmitted back to the instrument from the process stream. The instrument was then used to demonstrate that it could create real-time predictions of the acid concentrations. The results from this test showed that the instrument could accurately predict the acid concentrations to within ~0.15% acid strength, and this level of prediction proved to be similar or better then the laboratory analysis. By utilizing a sensor for process monitoring the most economic acid concentrations can be maintained. A single smaller refinery (50,000 barrels/day) estimates that they should save over $120,000/year, with larger refineries saving considerably more.

  16. Production of organic acid esters from biomass - novel processes and concepts

    SciTech Connect

    Datta, R.

    1981-01-01

    After low cost, low energy pretreatment, lignocellulose can be converted directly to volatile (C/sub 2/-C/sub 6/) organic acids by mixed-culture acidogenic fermentation. The principal components of lignocellulose (pectins, hemicellulose, cellulose, and lignin) are all converted to organic acids in high yields. Esterification from dilute aqueous solutions using novel techniques based on adsorption, solvent extraction, or biochemical conversion could be an important method for recovering these acids and simultaneously producing liquid fuels or chemical feedstocks. Uses of organic acid esters and conceptual biomass conversion processes are outlined. The significance of these processes for substantially increasing liquid fuel productivity from biomass feedstocks are discussed.

  17. Novel Biomass Conversion Process Results in Commercial Joint Venture; The Spectrum of Clean Energy Innovation (Fact Sheet)

    SciTech Connect

    Not Available

    2010-06-01

    Fact sheet describing DuPont/NREL cooperative research and development agreement that resulted in biomass-to-ethanol conversion process used as a basis for DuPont Danisco Cellulosic Ethanol, LLC and cellulosic ethanol demonstration plant.

  18. Clean Cities Fact Sheet

    SciTech Connect

    Not Available

    2004-01-01

    This fact sheet explains the Clean Cities Program and provides contact information for all coalitions and regional offices. It answers key questions such as: What is the Clean Cities Program? What are alternative fuels? How does the Clean Cities Program work? What sort of assistance does Clean Cities offer? What has Clean Cities accomplished? What is Clean Cities International? and Where can I find more information?

  19. Ultrasonic cleaning of fuel assemblies

    SciTech Connect

    Kondoh, Keisuke; Fujita, Chitoshi; Sakai, Hitoshi

    1994-12-31

    During fuel transportation, contamination of the transfer cask can lead to radiation dosage. That is radioactive crud becomes detached from the fuel surface and is deposited inside the cask. To avoid this at the Tsuruga Power Station Unit 1, crud was removed from fuel assemblies in advance of fuel transportation work. An ultrasonic cleaning process was adopted for this purpose; ultrasonic methods excel over other methods for this type of cleaning. Our process is also able to clean fuel assemblies without removing the channel box. Since this is the first time that the ultrasonic method was applied to fuel assemblies at the light water reactor in Japan on a large scale, the efficiency and the impact on plant instrumentation of the method were examined by performing preliminary test. Based on these tests, an optimum cleaning procedure was established.

  20. Ultrasonic cleaning of root canals

    NASA Astrophysics Data System (ADS)

    Verhaagen, Bram; Boutsioukis, Christos; Jiang, Lei-Meng; Macedo, Ricardo; van der Sluis, Luc; Versluis, Michel

    2011-11-01

    A crucial step during a dental root canal treatment is irrigation, where an antimicrobial fluid is injected into the root canal system to eradicate all bacteria. Agitation of the fluid using an ultrasonically vibrating miniature file has shown significant improvement in cleaning efficacy over conventional syringe irrigation. However, the physical mechanisms underlying the cleaning process, being acoustic streaming, cavitation or chemical activity, and combinations thereof, are not fully understood. High-speed imaging allows us to visualize the flow pattern and cavitation in a root canal model at microscopic scales, at timescales relevant to the cleaning processes (microseconds). MicroPIV measurements of the induced acoustic streaming are coupled to the oscillation characteristics of the file as simulated numerically and measured with a laser vibrometer. The results give new insight into the role of acoustic streaming and the importance of the confinement for the cleaning of root canals.

  1. SULFURIC ACID REMOVAL PROCESS EVALUATION: LONG-TERM RESULTS

    SciTech Connect

    Gary M. Blythe; Richard McMillan

    2002-07-03

    The objective of this project is to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. The project is being co-funded by the U.S. DOE National Energy Technology Laboratory, under Cooperative Agreement DE-FC26-99FT40718, along with EPRI, the American Electric Power Company (AEP), FirstEnergy Corp., the Tennessee Valley Authority, and Dravo Lime, Inc. Sulfuric acid controls are becoming of increasing interest to power generators with coal-fired units for a number of reasons. Sulfuric acid is a Toxic Release Inventory species and can cause a variety of plant operation problems such as air heater plugging and fouling, back-end corrosion, and plume opacity. These issues will likely be exacerbated with the retrofit of selective catalytic reduction (SCR) for NO{sub x} control on many coal-fired plants, as SCR catalysts are known to further oxidize a portion of the flue gas SO{sub 2} to SO{sub 3}. The project previously tested the effectiveness of furnace injection of four different calcium-and/or magnesium-based alkaline sorbents on full-scale utility boilers. These reagents were tested during four one- to two-week tests conducted on two FirstEnergy Bruce Mansfield Plant (BMP) units. One of the sorbents tested was a magnesium hydroxide byproduct slurry produced from a modified Thiosorbic{reg_sign} Lime wet flue gas desulfurization system. The other three sorbents are available commercially and include dolomite, pressure-hydrated dolomitic lime, and commercial magnesium hydroxide. The dolomite reagent was injected as a dry powder through out-of-service burners, while the other three reagents were injected as slurries through air-atomizing nozzles inserted through the front wall of the upper furnace, either across from the nose of the furnace or across from the pendant superheater tubes. After completing the four one- to two-week tests, the most promising sorbents were selected for

  2. Recovery Processes of Organic Acids from Fermentation Broths in the Biomass-Based Industry.

    PubMed

    Li, Qian-Zhu; Jiang, Xing-Lin; Feng, Xin-Jun; Wang, Ji-Ming; Sun, Chao; Zhang, Hai-Bo; Xian, Mo; Liu, Hui-Zhou

    2016-01-01

    The new movement towards green chemistry and renewable feedstocks makes microbial production of chemicals more competitive. Among the numerous chemicals, organic acids are more attractive targets for process development efforts in the renewable-based biorefinery industry. However, most of the production costs in microbial processes are higher than that in chemical processes, among which over 60% are generated by separation processes. Therefore, the research of separation and purification processes is important for a promising biorefinery industry. This review highlights the progress of recovery processes in the separation and purification of organic acids, including their advantages and disadvantages, current situation, and future prospects in terms of recovery yields and industrial application. PMID:26403818

  3. Production of organic acids by electrodialysis/pervaporation process.

    SciTech Connect

    Tsai, S. P.; Datta, R.; Henry, M.; Halpern, Y.; Frank, J. R.; Energy Systems

    1999-05-01

    Lactate esters produced from carbohydrates have potential markets as nontoxic replacements for halogenated and toxic solvents and as feedstocks for large-volume chemicals and polymers. Argonne National Laboratory has developed a novel process for the production of high-purity lactate esters from carbohydrates. The process uses advanced electrodialysis and pervaporation technologies to overcome major technical barriers in product separation; more specifically, the process involves cation elimination without the generation of salt waste and efficient esterification for final purification. This patented process requires little energy input, is highly efficient and selective, avoids the large volumes of salt waste produced by conventional processes, and significantly reduces manufacturing costs. The enabling membrane separation technologies make it technically and commercially feasible for lactate esters to penetrate the potential markets.

  4. Simulation of a waste incineration process with flue-gas cleaning and heat recovery sections using Aspen Plus.

    PubMed

    Cimini, Silvano; Prisciandaro, Marina; Barba, Diego

    2005-01-01

    In the present paper, the modeling of a dual-purpose plant for the production of electrical and thermal energy from the heat treatment of solid wastes is presented. Particularly, the process has been modeled by using the Aspen Plus Shell, with the aim of performing a study about the applicability of this software in the simulation of a solid waste incineration process, which involves complex gas-solid reactions where the solids are referred to as "non-conventional". The model is developed to analyze and quantify the expected benefits associated with refuse derived fuel (RDF) thermal utilization; thus attention is focused on the performance of the energy recovery section. PMID:15737714

  5. Innovative Clean Coal Technologies (ICCT): Demonstration of innovative applications of technology for cost reductions to the CT-121 FGD process

    SciTech Connect

    Not Available

    1992-05-15

    The objective of this project is to demonstrate on a commercial scale several innovative applications of cost-reducing technology to the Chiyoda Thoroughbred-121 (CT-121) process. CT-121 is a second generation flue gas desulfurization (FGD) process which is considered by the Electric Power Research Institute (EPRI) and Southern Company Services (SCS) to be one of the most reliable and lowest cost FGD options for high-sulfur coal-fired utility boiler applications. Demonstrations of the innovative design approaches will further reduce the cost and provide a clear advantage to CT121 relative to competing technology.

  6. Innovative Clean Coal Technology (ICCT): Demonstration of innovative applications of technology for cost reductions to the CT-121 FGD process

    SciTech Connect

    Not Available

    1992-02-15

    The objective of this project is to demonstrate on a commercial scale several innovative applications of cost-reducing technology to the Chiyoda Thoroughbred-121 (CT-121) process. CT-121 is a second generation flue gas desulfurization (FGD) process which is considered by the Electric Power Research Institute (EPRI) and Southern Company Services (SCS) to be one of the most reliable and lowest cost FGD options for high-sulfur coal-fired utility boiler applications. Demonstrations of the innovative design approaches will further reduce the cost and provide a clear advantage to CT121 relative to competing technology.

  7. Green cleaning technologies

    SciTech Connect

    Knipe, R.

    1997-08-01

    Selecting environmentally safe metal cleaning alternatives requires a personal, careful, and comprehensive study. Before the days of depleting-the-ozone studies and volatile organic compound (VOC) regulations, the selection of a cleaning method for a particular metal process was simply tied to cost and result. Little, if any, consideration was given to the personal health of the operator or potential environmental impact. Nothing will ever be as simple as using methyl chloroform or other chlorinated solvents in a vapor degreaser. However, similar results can be achieved with greener technologies, provided that suitable procedures are followed. This article lists the questions to ask to properly evaluate current practices, explains the benefits and limitations of spray and immersion systems, describes environmentally benign aqueous and non-chlorinated solvent applications, and shows how to dispose of wastewater.

  8. Bifunctional phenyl monophosphonic/sulfonic acid ion exchange resin and process for using the same

    DOEpatents

    Alexandratos, Spiro; Shelley, Christopher A.; Horwitz, E. Philip; Chiarizia, Renato; Gula, Michael J.; Xue, Sui; Harvey, James T.

    2002-01-01

    A cross-linked water-insoluble ion exchange resin comprised of polymerized monomers having a phenyl ring is disclosed. A contemplated resin contains (i) polymerized phenyl ring-containing monomers having a phosphonic acid ligand linked to the phenyl ring, (ii) about 2 to about 5 millimoles per gram (mmol/g) of phosphorus as phosphonic acid ligands, and (iii) a sufficient amount of a sulfonic acid ligand such that the ratio of mmol/g of phosphonic acid to mmol/g sulfonic acid is up to 3:1. A process for removing polyvalent metal cations from aqueous solution, and a process for removing iron(III) cations from acidic copper(II) cation-containing solutions that utilize the contemplated resin or other resins are disclosed.

  9. Bifunctional phenyl monophosphonic/sulfonic acid ion exchange resin and process for using the same

    DOEpatents

    Alexandratos, Spiro; Shelley, Christopher A.; Horwitz, E. Philip; Chiarizia, Renato

    2001-01-01

    A cross-linked water-insoluble ion exchange resin comprised of polymerized monomers having a phenyl ring is disclosed. A contemplated resin contains (i) polymerized phenyl ring-containing monomers having a phosphonic acid ligand linked to the phenyl ring, (ii) about 2 to about 5 millimoles per gram (mmol/g) of phosphorus as phosphonic acid ligands, and (iii) a sufficient amount of a sulfonic acid ligand such that the ratio of mmol/g of phosphonic acid to mmol/g sulfonic acid is up to 3:1. A process for removing polyvalent metal cations from aqueous solution, and a process for removing iron(III) cations from acidic copper(II) cation-containing solutions that utilize the contemplated resin or other resins are disclosed.

  10. CNG process, a new approach to physical-absorption acid-gas removal

    SciTech Connect

    Hise, R.E.; Massey, L.G.; Adler, R.J.; Brosilow, C.B.; Gardner, N.C.; Brown, W.R.; Cook, W.J.; Petrik, M.

    1982-01-01

    The CNG acid gas removal process embodies three novel features: (1) scrubbing with liquid carbon dioxide to remove all sulfurous molecules and other trace contaminants; (2) triple-point crystallization of carbon dioxide to concentrate sulfurous molecules and produce pure carbon dioxide; and (3) absorption of carbon dioxide with a slurry of solid carbon dioxide in organic carrier liquid. The CNG process is discussed and contrasted with existing acid gas removal technology as represented by the Benfield, Rectisol, and Selexol acid gas removal processes.

  11. Malonic acid: A potential reagent in decontamination processes for Ni-rich alloy surfaces

    NASA Astrophysics Data System (ADS)

    García, D.; Bruyère, V. I. E.; Bordoni, R.; Olmedo, A. M.; Morando, P. J.

    2011-05-01

    The ability of malonic acid as a dissolution agent toward synthetic Ni ferrite and Alloy 600 and 800 corrosion products was explored. Its performance in the dissolution kinetics of Ni ferrite powders was compared with the one of oxalic acid. Kinetic parameters were obtained and the dependency on external Fe(II) was modelled. Oxidized samples used in descaling tests were prepared by exposure of coupons of both alloys to lithiated aqueous solutions, under hydrothermal conditions and hydrogen overpressure, simulating PHWR conditions. Oxide layer morphology, the influence of exposure time to corrosive medium and LiOH concentration on its thickness were characterized. Descaling tests consisting on a two-stage method (a first oxidizing step with alkaline permanganate followed by a reducing step with oxalic or malonic acid were carried out). Results were compared to those obtained with a well known chemical cleaning formulation (APAC: Alkaline Permanganate Ammonium Citrate) used in decontamination of several reactors and loops and the competitiveness of malonic acid was demonstrated.

  12. 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

    SciTech Connect

    Olfenbuttel, R.; Clark, S.; Helper, E.; Hinchee, R.; Kuntz, C.; Means, J.; Oxley, J.; Paisley, M.; Rogers, C.; Sheppard, W.; Smolak, L.

    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.

  13. Automated carbon dioxide cleaning system

    NASA Technical Reports Server (NTRS)

    Hoppe, David T.

    1991-01-01

    Solidified CO2 pellets are an effective blast media for the cleaning of a variety of materials. CO2 is obtained from the waste gas streams generated from other manufacturing processes and therefore does not contribute to the greenhouse effect, depletion of the ozone layer, or the environmental burden of hazardous waste disposal. The system is capable of removing as much as 90 percent of the contamination from a surface in one pass or to a high cleanliness level after multiple passes. Although the system is packaged and designed for manual hand held cleaning processes, the nozzle can easily be attached to the end effector of a robot for automated cleaning of predefined and known geometries. Specific tailoring of cleaning parameters are required to optimize the process for each individual geometry. Using optimum cleaning parameters the CO2 systems were shown to be capable of cleaning to molecular levels below 0.7 mg/sq ft. The systems were effective for removing a variety of contaminants such as lubricating oils, cutting oils, grease, alcohol residue, biological films, and silicone. The system was effective on steel, aluminum, and carbon phenolic substrates.

  14. FY13 GLYCOLIC-NITRIC ACID FLOWSHEET DEMONSTRATIONS OF THE DWPF CHEMICAL PROCESS CELL WITH SIMULANTS

    SciTech Connect

    Lambert, D.; Zamecnik, J.; Best, D.

    2014-03-13

    Savannah River Remediation is evaluating changes to its current Defense Waste Processing Facility flowsheet to replace formic acid with glycolic acid in order to improve processing cycle times and decrease by approximately 100x the production of hydrogen, a potentially flammable gas. Higher throughput is needed in the Chemical Processing Cell since the installation of the bubblers into the melter has increased melt rate. Due to the significant maintenance required for the safety significant gas chromatographs and the potential for production of flammable quantities of hydrogen, eliminating the use of formic acid is highly desirable. Previous testing at the Savannah River National Laboratory has shown that replacing formic acid with glycolic acid allows the reduction and removal of mercury without significant catalytic hydrogen generation. Five back-to-back Sludge Receipt and Adjustment Tank (SRAT) cycles and four back-to-back Slurry Mix Evaporator (SME) cycles were successful in demonstrating the viability of the nitric/glycolic acid flowsheet. The testing was completed in FY13 to determine the impact of process heels (approximately 25% of the material is left behind after transfers). In addition, back-to-back experiments might identify longer-term processing problems. The testing was designed to be prototypic by including sludge simulant, Actinide Removal Product simulant, nitric acid, glycolic acid, and Strip Effluent simulant containing Next Generation Solvent in the SRAT processing and SRAT product simulant, decontamination frit slurry, and process frit slurry in the SME processing. A heel was produced in the first cycle and each subsequent cycle utilized the remaining heel from the previous cycle. Lower SRAT purges were utilized due to the low hydrogen generation. Design basis addition rates and boilup rates were used so the processing time was shorter than current processing rates.

  15. Dihydrolipoic acid induces cytotoxicity in mouse blastocysts through apoptosis processes.

    PubMed

    Houng, Wei-Li; Lin, Cheng-An J; Shen, Ji-Lin; Yeh, Hung-I; Wang, Hsueh-Hsiao; Chang, Walter H; Chan, Wen-Hsiung

    2012-01-01

    α-Lipoic acid (LA) is a thiol with antioxidant properties that protects against oxidative stress-induced apoptosis. LA is absorbed from the diet, taken up by cells and tissues, and subsequently reduced to dihydrolipoic acid (DHLA). In view of the recent application of DHLA as a hydrophilic nanomaterial preparation, determination of its biosafety profile is essential. In the current study, we examined the cytotoxic effects of DHLA on mouse embryos at the blastocyst stage, subsequent embryonic attachment and outgrowth in vitro, in vivo implantation by embryo transfer, and early embryonic development in an animal model. Blastocysts treated with 50 μM DHLA exhibited significantly increased apoptosis and a corresponding decrease in total cell number. Notably, the implantation success rates of blastocysts pretreated with DHLA were lower than that of their control counterparts. Moreover, in vitro treatment with 50 μM DHLA was associated with increased resorption of post-implantation embryos and decreased fetal weight. Data obtained using an in vivo mouse model further disclosed that consumption of drinking water containing 100 μM DHLA led to decreased early embryo development, specifically, inhibition of development to the blastocyst stage. However, it appears that concentrations of DHLA lower than 50 μM do not exert a hazardous effect on embryonic development. Our results collectively indicate that in vitro and in vivo exposure to concentrations of DHLA higher than 50 μM DHLA induces apoptosis and retards early pre- and post-implantation development, and support the potential of DHLA to induce embryonic cytotoxicity. PMID:22489194

  16. Development of a chemical process using nitric acid-cerium(IV) for decontamination of high-level waste canisters

    SciTech Connect

    Bray, L.A.

    1988-06-01

    A simple and effective method was developed for contamination of high-level waste containers. This method of chemical decontamination is applicable to a wide variety of contaminated equipment found in the nuclear industry. The process employs a oxidant system (Ce(IV)) in nitric acid (HNO/sub 3/) solution to chemically mill a thin layer from the canister surface. Contaminated canisters are simply immersed in the solution at a controlled temperature and Ce(IV) concentration level. The spent solution is discarded to the high-level waste stream and added to subsequent glass batches. The Ce(IV)/HNO/sub 3/ solution has been shown to be effective in chemically milling the surface of stainless steel, similar to the electropolishing process, but without the need for an applied electrical current. West Valley (WV) staff had previously evaluated several canister decontamination methods, including electropolishing, liquid abrasive blast, high-pressure water wash, and ultrasonic cleaning, before the Ce(IV)/HNO/sub 3/ redox solution on treatment was selected. The initial concept involved continuous electrochemical regeneration of the ceric ion. Extensive in-cell pumping and close-coupled heat transfer and electrochemical equipment were required. The objective of this study, was to simplify the original concept. 2 refs., 16 figs., 4 tabs.

  17. Activators of Biochemical and Physiological Processes in Plants Based on Fine Humic Acids

    NASA Astrophysics Data System (ADS)

    Churilov, G.; Polishuk, S.; Kutskir, M.; Churilov, D.; Borychev, S.

    2015-11-01

    This article describes the application of ultrafine humic acids as growth promoters and development of crops, for example corn. During the study we determined the optimal concentration of humic acids in ultrafine state for presowing treatment of seeds of maize. An analysis of laboratory and field tests was presented. We showed the relationship between physiological changes and biochemical processes.

  18. Saltstone Clean Cap Formulation

    SciTech Connect

    Langton, C

    2005-04-22

    The current operation strategy for using Saltstone Vault 4 to receive 0.2 Ci/gallon salt solution waste involves pouring a clean grout layer over the radioactive grout prior to initiating pour into another cell. This will minimize the radiating surface area and reduce the dose rate at the vault and surrounding area. The Clean Cap will be used to shield about four feet of Saltstone poured into a Z-Area vault cell prior to moving to another cell. The minimum thickness of the Clean Cap layer will be determined by the cesium concentration and resulting dose levels and it is expected to be about one foot thick based on current calculations for 0.1 Ci Saltstone that is produced in the Saltstone process by stabilization of 0.2 Ci salt solution. This report documents experiments performed to identify a formulation for the Clean Cap. Thermal transient calculations, adiabatic temperature rise measurements, pour height, time between pour calculations and shielding calculations were beyond the scope and time limitations of this study. However, data required for shielding calculations (composition and specific gravity) are provided for shielding calculations. The approach used to design a Clean Cap formulation was to produce a slurry from the reference premix (10/45/45 weight percent cement/slag/fly ash) and domestic water that resembled as closely as possible the properties of the Saltstone slurry. In addition, options were investigated that may offer advantages such as less bleed water and less heat generation. The options with less bleed water required addition of dispersants. The options with lower heat contained more fly ash and less slag. A mix containing 10/45/45 weight percent cement/slag/fly ash with a water to premix ratio of 0.60 is recommended for the Clean Cap. Although this mix may generate more than 3 volume percent standing water (bleed water), it has rheological, mixing and flow properties that are similar to previously processed Saltstone. The recommended

  19. Two Molecular Information Processing Systems Based on Catalytic Nucleic Acids

    NASA Astrophysics Data System (ADS)

    Stojanovic, Milan

    Mixtures of molecules are capable of powerful information processing [1]. This statement is in the following way self-evident: it is a hierarchically organized complex mixture of molecules that is formulating it to other similarly organized mixtures of molecules. By making such a statement I am not endorsing the extreme forms of reductionism; rather, I am making what I think is a small first step towards harnessing information processing prowess of molecules and, hopefully, overcoming some limitations of more traditional computing paradigms. There are different ideas on how to understand and use molecular information processing abilities and I will list some below. My list is far from inclusive, and delineations are far from clear-cut; whenever available, I will provide examples from our research efforts. I should stress, for a computer science audience that I am a chemist. Thus, my approach may have much different focus and mathematical rigor, then if it would be taken by a computer scientist.

  20. Experimental and simulation studies of printability of buried EUV mask defects and study of EUV reflectivity loss mechanisms due to standard EUV mask cleaning processes

    NASA Astrophysics Data System (ADS)

    Upadhyaya, Mihirkant

    There's a big push for development and commercialization of extreme ultraviolet (EUV) lithography for high-volume semiconductor manufacturing of 14 nm half-pitch patterning and beyond. One of the primary concerns for making this a reality has been the ability to achieve defect-free masks. My study is focused on two aspects related to the performance degradation of the EUV masks namely EUV mask cleaning induced reflectivity loss mechanisms, and the buried multilayer phase defects in EUV masks. Standard EUV mask cleaning processes involve various steps and chemistries that lead to degradation of the multilayer structure, in turn leading to EUV reflectivity loss, hence impacting the throughput. In this work, we developed an understanding of the root causes of how different cleaning chemistries cause EUV reflectivity loss, and quantified these losses. Upon subjecting the mask blanks to multiple cleaning cycles, multilayer degradation observed was in terms of multilayer etching and pitting, surface roughness increase and surface oxidation. We studied each of these phenomena through experiments and simulations, and correlated the extent of EUV reflectivity loss to each of the degradation phenomena. The second aspect of this work involved investigating the printability behavior of buried native phase defects in EUV mask blanks. Since completely defect-free masks will be hard to achieve, it is essential to have a good understanding of the printability of EUV mask defects. In this work, the printability of native mask defects was studied using a novel level-set multilayer growth model that took into account the tool deposition conditions where the multilayer deposition took place. For this study, the native mask blank defects were characterized using atomic force microscopy (AFM) and cross-section transmission electron microscopy (TEM), and the defect printability of these defects was evaluated using simulations implementing the finite-difference time-domain (FDTD) and the

  1. Combined wet and dry cleaning of SiGe(001)

    SciTech Connect

    Park, Sang Wook; Kaufman-Osborn, Tobin; Kim, Hyonwoong; Siddiqui, Shariq; Sahu, Bhagawan; Yoshida, Naomi; Brandt, Adam; Kummel, Andrew C.

    2015-07-15

    Combined wet and dry cleaning via hydrofluoric acid (HF) and atomic hydrogen on Si{sub 0.6}Ge{sub 0.4}(001) surface was studied at the atomic level using ultrahigh vacuum scanning tunneling microscopy (STM), scanning tunneling spectroscopy (STS), and x-ray photoelectron spectroscopy to understand the chemical transformations of the surface. Aqueous HF removes native oxide, but residual carbon and oxygen are still observed on Si{sub 0.6}Ge{sub 0.4}(001) due to hydrocarbon contamination from post HF exposure to ambient. The oxygen contamination can be eliminated by shielding the sample from ambient via covering the sample in the HF cleaning solution until the sample is introduced to the vacuum chamber or by transferring the sample in an inert environment; however, both processes still leave carbon contaminant. Dry in-situ atomic hydrogen cleaning above 330 °C removes the carbon contamination on the surface consistent with a thermally activated atomic hydrogen reaction with surface hydrocarbon. A postdeposition anneal at 550 °C induces formation of an atomically flat and ordered SiGe surface observed by STM. STS verifies that the wet and dry cleaned surface has an unpinned Fermi level with no states between the conduction and valence band edge comparable to sputter cleaned SiGe surfaces.

  2. Process and apparatus for obtaining silicon from fluosilicic acid

    DOEpatents

    Nanis, Leonard; Sanjurjo, Angel

    1988-05-31

    Process for producing low cost, high purity solar grade Si wherein a reduction reaction, preferably the reduction of SiF.sub.4, by an alkali metal (Na preferred) is carried out inside a reaction chamber. The chamber wall and bottom surfaces are configured so as to facilitate the continuous separation of the products of reaction (Si and NaF) and removal of the molten salt by discharging the salt through one or more ports at the bottom of the reaction chamber. Such process is especially useful where it is desirable to discharge the reaction salt products from the reactor and retain silicon within the chamber for later removal.

  3. Process for the removal of radium from acidic solutions containing same

    DOEpatents

    Scheitlin, F.M.

    The invention is a process for the removal of radium from acidic aqueous solutions. In one aspect, the invention is a process for removing radium from an inorganic-acid solution. The process comprises contacting the solution with coal fly ash to effect adsorption of the radium on the ash. The radium-containing ash then is separated from the solution. The process is simple, comparatively inexpensive, and efficient. High radium-distribution coefficients are obtained even at room temperature. Coal fly ash is an inexpensive, acid-resistant, high-surface-area material which is available in large quantities throughout the United States. The invention is applicable, for example, to the recovery of /sup 226/Ra from nitric acid solutions which have been used to leach radium from uranium-mill tailings.

  4. High-yield production of biosugars from Gracilaria verrucosa by acid and enzymatic hydrolysis processes.

    PubMed

    Kim, Se Won; Hong, Chae-Hwan; Jeon, Sung-Wan; Shin, Hyun-Jae

    2015-11-01

    Gracilaria verrucosa, the red alga, is a suitable feedstock for biosugar production. This study analyzes biosugar production by the hydrolysis of G. verrucosa conducted under various conditions (i.e., various acid concentrations, substrate concentrations, reaction times, and enzyme dosages). The acid hydrolysates of G. verrucosa yielded a total of 7.47g/L (37.4%) and 10.63g/L (21.26%) of reducing sugars under optimal small (30mL) and large laboratory-scale (1L) hydrolysis processes, respectively. Reducing sugar obtained from acid and enzymatic hydrolysates were 10% higher, with minimum by-products, than those reported in other studies. The mass balance for the small laboratory-scale process showed that the acid and enzymatic hydrolysates had a carbohydrate conversion of 57.2%. The mass balance approach to the entire hydrolysis process of red seaweed for biosugar production can be applied to other saccharification processes. PMID:26299978

  5. Clean solutions to the incoming wafer quality impact on lithography process yield limits in a dynamic copper/low-k research and development environment

    NASA Astrophysics Data System (ADS)

    Lysaght, Patrick S.; Ybarra, Israel; Sax, Harry; Gupta, Gaurav; West, Michael; Doros, Theodore G.; Beach, James V.; Mello, Jim

    2000-06-01

    The continued growth of the semiconductor manufacturing industry has been due, in large part, to improved lithographic resolution and overlay across increasingly larger chip areas. Optical lithography continues to be the mainstream technology for the industry with extensions of optical lithography being employed to support 180 nm product and process development. While the industry momentum is behind optical extensions to 130 nm, the key challenge will be maintaining an adequate and affordable process latitude (depth of focus/exposure window) necessary for 10% post-etch critical dimension (CD) control. If the full potential of optical lithography is to be exploited, the current lithographic systems can not be compromised by incoming wafer quality. Impurity specifications of novel Low-k dielectric materials, plating solutions, chemical-mechanical planarization (CMP) slurries, and chemical vapor deposition (CVD) precursors are not well understood and more stringent control measures will be required to meet defect density targets as identified in the National Technology Roadmap for Semiconductors (NTRS). This paper identifies several specific poor quality wafer issues that have been effectively addressed as a result of the introduction of a set of flexible and reliable wafer back surface clean processes developed on the SEZ Spin-Processor 203 configured for processing of 200 mm diameter wafers. Patterned wafers have been back surface etched by means of a novel spin process contamination elimination (SpCE) technique with the wafer suspended by a dynamic nitrogen (N2) flow, device side down, via the Bernoulli effect. Figure 1 illustrates the wafer-chuck orientation within the process chamber during back side etch processing. This paper addresses a number of direct and immediate benefits to the MicraScan IIITM deep-ultraviolet (DUV) step-and-scan system at SEMATECH. These enhancements have resulted from the resolution of three significant problems: (1) back surface

  6. Process and apparatus for obtaining silicon from fluosilicic acid

    DOEpatents

    Sancier, Kenneth M.

    1985-07-16

    Process for producing low cost, high purity solar grade Si wherein a reduction reaction, preferably the reduction of SiF.sub.4, by an alkali metal (liquid Na preferred) is carried out essentialy continuously by injecting of reactants in substantially stoichiometric proportions into a reaction chamber having a controlled temperature thereby to form a mist or dispersion of reactants. The reactants being supplied at such a rate and temperature that the reaction takes place far enough away from the entry region to avoid plugging of reactants at the entry region, the reaction is completed and whereby essentially all reaction product solidifies and forms a free flowing powder before reaction product hits a reaction chamber wall. Thus, the reaction product does not adhere to the reaction chamber wall or pick up impurities therefrom. Separation of reaction products is easily carried out by either a leach or melt separation process.

  7. Senate passes clean air bill

    NASA Astrophysics Data System (ADS)

    In an 89 to 11 vote the Senate passed a clean air bill aimed at reducing pollution by the turn of the century by imposing tougher controls on American industry. The bill is the first revision of the Clean Air Act of 1970 in 13 years and calls for new limits on auto pollution to clean up smog in most U.S. cities, decreasing by half emissions by power plants that cause acid rain to protect the ecology, and increasing technological controls on factories to protect against cancer-causing and toxic substances. The bill will add about $20 billion per year to the estimated $33 billion cost of complying with current pollution laws.

  8. Formation of cloud condensation nuclei by oxidative processing: Unsaturated fatty acids

    NASA Astrophysics Data System (ADS)

    Broekhuizen, Keith E.; Thornberry, Troy; Kumar, P. Pradeep; Abbatt, Jonathan P. D.

    2004-12-01

    The ability of submicron oleic acid and linoleic acid particles, or condensation nuclei (CN), to act as cloud condensation nuclei (CCN) has been investigated using a tandem differential mobility analyzer (TDMA) coupled to a flow tube reactor and a thermal gradient diffusion chamber (TGDC). The size change and CCN properties of pure oleic acid, mixed oleic acid/methanol, and pure linoleic acid particles have been investigated as a function of exposure to ozone. Pure oleic and linoleic acid particles were CCN inactive for all particle diameters (≤300 nm) and supersaturations (≤1%) studied. The mixed oleic acid/methanol particles, however, had a critical activation diameter of 188 nm for an experimental water supersaturation of 0.6%. Under low ozone exposures (<1 × 10-4 atm s), both the oleic acid and linoleic acid particles decreased in size. In particular, oleic acid particles lost 25% of their initial volume, consistent with the loss of nonanal, a volatile reaction product. However, no increase in CCN activity was observed at these exposures. Under conditions of much higher ozone exposure, e.g., 0.42 atm s, the pure oleic acid particles became CCN active, with a critical activation diameter of 161 nm at 0.6% supersaturation. CCN activity for the linoleic acid particles was never observed, even under these high ozone exposures not typically observed in the atmosphere. By contrast, the mixed oleic acid/methanol particles showed enhanced activation under atmospherically relevant ozone exposures (<1 × 10-4 atm s). These results suggest that the products of the ozone plus unsaturated fatty acid reaction do promote the CCN activity of the particles; however, the degree of activity is dependent on both the level of ozone exposure and the chemical nature of the particle. These results are the first to demonstrate that the CCN properties of pure organic aerosols can be modified through oxidative processing.

  9. Perfluoroalkyl Acid Concentrations in Blood Samples Subjected to Transportation and Processing Delay

    PubMed Central

    Bach, Cathrine Carlsen; Henriksen, Tine Brink; Bossi, Rossana; Bech, Bodil Hammer; Fuglsang, Jens; Olsen, Jørn; Nohr, Ellen Aagaard

    2015-01-01

    Background In studies of perfluoroalkyl acids, the validity and comparability of measured concentrations may be affected by differences in the handling of biospecimens. We aimed to investigate whether measured plasma levels of perfluoroalkyl acids differed between blood samples subjected to delay and transportation prior to processing and samples with immediate processing and freezing. Methods Pregnant women recruited at Aarhus University Hospital, Denmark, (n = 88) provided paired blood samples. For each pair of samples, one was immediately processed and plasma was frozen, and the other was delayed and transported as whole blood before processing and freezing of plasma (similar to the Danish National Birth Cohort). We measured 12 perfluoroalkyl acids and present results for compounds with more than 50% of samples above the lower limit of quantification. Results For samples taken in the winter, relative differences between the paired samples ranged between -77 and +38% for individual perfluoroalkyl acids. In most cases concentrations were lower in the delayed and transported samples, e.g. the relative difference was -29% (95% confidence interval -30; -27) for perfluorooctane sulfonate. For perfluorooctanoate there was no difference between the two setups [corresponding estimate 1% (0, 3)]. Differences were negligible in the summer for all compounds. Conclusions Transport of blood samples and processing delay, similar to conditions applied in some large, population-based studies, may affect measured perfluoroalkyl acid concentrations, mainly when outdoor temperatures are low. Attention to processing conditions is needed in studies of perfluoroalkyl acid exposure in humans. PMID:26356420

  10. Effect of SPM-based cleaning POR on EUV mask performance

    NASA Astrophysics Data System (ADS)

    Choi, Jaehyuck; Lee, Han-shin; Yoon, Jinsang; Shimomura, Takeya; Friz, Alex; Montgomery, Cecilia; Ma, Andy; Goodwin, Frank; Kang, Daehyuk; Chung, Paul; Shin, Inkyun; Cho, H.

    2011-11-01

    EUV masks include many different layers of various materials rarely used in optical masks, and each layer of material has a particular role in enhancing the performance of EUV lithography. Therefore, it is crucial to understand how the mask quality and patterning performance can change during mask fabrication, EUV exposure, maintenance cleaning, shipping, or storage. The fact that a pellicle is not used to protect the mask surface in EUV lithography suggests that EUV masks may have to undergo more cleaning cycles during their lifetime. More frequent cleaning, combined with the adoption of new materials for EUV masks, necessitates that mask manufacturers closely examine the performance change of EUV masks during cleaning process. We have investigated EUV mask quality and patterning performance during 30 cycles of Samsung's EUV mask SPM-based cleaning and 20 cycles of SEMATECH ADT exposure. We have observed that the quality and patterning performance of EUV masks does not significantly change during these processes except mask pattern CD change. To resolve this issue, we have developed an acid-free cleaning POR and substantially improved EUV mask film loss compared to the SPM-based cleaning POR.

  11. Process for the preparation of 3,4-dihydroxybutanoic acid and salts thereof

    DOEpatents

    Hollingsworth, Rawle I.

    1994-01-01

    A process for the preparation of 3,4-dihydroxybutanoic acid (1) and salts thereof from a glucose source containing 1,4-1inked glucose as a substituent is described. The process uses an alkali metal hdyroxide and hydrogen peroxide to convert the glucose source to (1). The compound (1) is useful as a chemical intermediate to naturally occurring fatty acids and is used to prepare 3,4-dihydroxybutanoic acid-gamma-lactone (2) and furanone (3), particularly stereoisomers of these compounds.

  12. Modeling aqueous ozone/UV process using oxalic acid as probe chemical.

    PubMed

    Garoma, Temesgen; Gurol, Mirat D

    2005-10-15

    A kinetic model that describes the removal of organic pollutants by an ozone/UV process is described. Oxalic acid, which reacts with a very low rate constant with ozone and relatively high rate constant with hydroxyl radical (OH*), was used as the probe chemical to model the process. The model was verified by experimental data on concentrations of oxalic acid and hydrogen peroxide (H202) under various experimental conditions, i.e., ozone gas dosage, UV light intensity, and varying oxalic acid concentrations. PMID:16295862

  13. Assessment of the potential suitability of selected commercially available enzymes for cleaning-in-place (CIP) in the dairy industry.

    PubMed

    Boyce, Angela; Piterina, Anna V; Walsh, Gary

    2010-10-01

    The potential suitability of 10 commercial protease and lipase products for cleaning-in-place (CIP) application in the dairy industry was investigated on a laboratory scale. Assessment was based primarily on the ability of the enzymes to remove an experimentally generated milk fouling deposit from stainless steel (SS) panels. Three protease products were identified as being most suitable for this application on the basis of their cleaning performance at 40 °C, which was comparable to that of the commonly used cleaning agent, 1% NaOH at 60 °C. This was judged by quantification of residual organic matter and protein on the SS surface after cleaning and analysis by laser scanning confocal microscopy (LSCM). Enzyme activity was removed/inactivated under conditions simulating those normally undertaken after cleaning (rinsing with water, acid circulation, sanitation). Preliminary process-scale studies strongly suggest that enzyme-based CIP achieves satisfactory cleaning at an industrial scale. Cost analysis indicates that replacing caustic-based cleaning procedures with biodegradable enzymes operating at lower temperatures would be economically viable. Additional potential benefits include decreased energy and water consumption, improved safety, reduced waste generation, greater compatibility with wastewater treatment processes and a reduction in the environmental impact of the cleaning process. PMID:20931416

  14. Clean fractionation of biomass

    SciTech Connect

    1995-09-01

    The US DOE Alternative Feedstocks (AF) program is forging new links between the agricultural community and the chemicals industry through support of research and development (R&D) that uses green feedstocks to produce chemicals. The program promotes cost-effective industrial use of renewable biomass as feedstocks to manufacture high-volume chemical building blocks. Industrial commercialization of such processes would stimulate the agricultural sector by increasing the demand of agricultural and forestry commodities. A consortium of five DOE national laboratories has been formed with the objectives of providing industry with a broad range of expertise and helping to lower the risk of new process development through federal cost sharing. The AF program is conducting ongoing research on a clean fractionation process, designed to convert biomass into materials that can be used for chemical processes and products. The focus of the clean fractionation research is to demonstrate to industry that one technology can successfully separate all types of feedstocks into predictable types of chemical intermediates.

  15. Determination of trans fatty acid levels by FTIR in processed foods in Australia.

    PubMed

    McCarthy, Justine; Barr, Daniel; Sinclair, Andrew

    2008-01-01

    Health authorities around the world advise 'limiting consumption of trans fatty acid', however in Australia the trans fatty acid (TFA) content is not required to be listed in the nutrition information panel unless a declaration or nutrient claim is made about fatty acids or cholesterol. Since there is limited knowledge about trans fatty acid levels in processed foods available in Australia, this study aimed to determine the levels of TFA in selected food items known to be sources of TFA from previously published studies. Food items (n=92) that contain vegetable oil and a total fat content greater than 5% were included. This criterion was used in conjunction with a review of similar studies where food items were found to contain high levels of trans fatty acids. Lipids were extracted using solvents. Gravimetric methods were used to determine total fat content and trans fatty acid levels were quantified by Attenuated Total Reflectance Fourier Transform Infrared spectroscopy. High levels of trans fatty acids were found in certain items in the Australian food supply, with a high degree of variability. Of the samples analysed, 13 contained greater than 1 g of trans fatty acids per serving size, the highest value was 8.1 g/serving. Apart from when the nutrition information panel states that the content is less than a designated low level, food labels sold in Australia do not indicate trans fatty acid levels. We suggested that health authorities seek ways to assist consumers to limit their intakes of trans fatty acids. PMID:18818158

  16. Steroidal aromatic 'naphthenic acids' in oil sands process-affected water: structural comparisons with environmental estrogens.

    PubMed

    Rowland, Steven J; West, Charles E; Jones, David; Scarlett, Alan G; Frank, Richard A; Hewitt, L Mark

    2011-11-15

    The large volumes, acute toxicity, estrogenicity, and antiandrogenicity of process-affected waters accruing in tailings ponds from the operations of the Alberta oil sands industries pose a significant task for environmental reclamation. Synchronous fluorescence spectra (SFS) suggest that oil sands process-affected water (OSPW) may contain aromatic carboxylic acids, which are among the potentially environmentally important toxicants, but no such acids have yet been identified, limiting interpretations of the results of estrogenicity and other assays. Here we show that multidimensional comprehensive gas chromatography-mass spectrometry (GCxGC-MS) of methyl esters of acids in an OSPW sample produces mass spectra consistent with their assignment as C(19) and C(20) C-ring monoaromatic hydroxy steroid acids, D-ring opened hydroxy and nonhydroxy polyhydrophenanthroic acids with one aromatic and two alicyclic rings and A-ring opened steroidal keto acids. High resolution MS data support the assignment of several of the so-called 'O3' species. When fractions of distilled, esterified, OSPW acid-extractable organics were examined, the putative aromatics were mainly present in a high boiling fraction; when examined by argentation thin layer chromatography, some were present in a fraction with a retardation factor between that of the methyl esters of synthetic monoalicyclic and monoaromatic acids. Ultraviolet absorption spectra of these fractions indicated the presence of benzenoid moieties. SFS of model octahydro- and tetrahydrophenanthroic acids produced emissions at the characteristic excitation wavelengths observed in some OSPW extracts, consistent with the postulations from ultraviolet spectroscopy and mass spectrometry data. We suggest the acids originate from extensive biodegradation of C-ring monoaromatic steroid hydrocarbons and offer a means of differentiating residues at different biodegradation stages in tailings ponds. Structural similarities with estrone and

  17. Impact of microfluidic processing on bacterial ribonucleic acid expression

    PubMed Central

    Gandi, Senthil Kumar; Watson, David; Kersaudy-Kerhoas, Maïwenn; Bachmann, Till; Bridle, Helen

    2015-01-01

    Bacterial transcriptomics is widely used to investigate gene regulation, bacterial susceptibility to antibiotics, host-pathogen interactions, and pathogenesis. Transcriptomics is crucially dependent on suitable methods to isolate and detect bacterial RNA. Microfluidics offer ways of creating integrated point-of-care systems, analysing a sample from preparation, and RNA isolation to detection. A critical requirement for on-chip diagnostics to deliver on their promise is that mRNA expression is not altered via microfluidic sample processing. This article investigates the impact of the use of microfluidics upon RNA expression of bacteria isolated from blood, a key step towards proving the suitability of such systems for further development. PMID:26045727

  18. Process and apparatus for obtaining silicon from fluosilicic acid

    DOEpatents

    Sanjurjo, Angel

    1988-06-28

    Process and apparatus for producing low cost, high purity solar grade silicon ingots in single crystal or quasi single crystal ingot form in a substantially continuous operation in a two stage reactor starting with sodium fluosilicate and a metal more electropositive than silicon (preferably sodium) in separate compartments having easy vapor transport therebetween and thermally decomposing the sodium fluosilicate to cause formation of substantially pure silicon and a metal fluoride which may be continuously separated in the melt and silicon may be directly and continuously cast from the melt.

  19. Steaming Clean

    ERIC Educational Resources Information Center

    Hoverson, Rick

    2006-01-01

    Schools can provide a cleaner, more healthful school environment by simply combining heat and water. Steam vapor systems use only tap water with no chemicals added. Low-pressure (12 psi to 65 psi) steam vapor sanitizes and deodorizes. This process can then be used safely in many situations, but is especially suited for restrooms and food-service…

  20. Clean Break

    ERIC Educational Resources Information Center

    Peterson, Erin

    2011-01-01

    An interim president has to perform a particularly difficult balancing act. He or she shoulders the burdens from--or legacy of--the previous president and must also provide a foundation of stability for the new president. Throughout the process, effective communication--both internally and externally--is critical to ensuring a smooth transition.…

  1. Processes and fluxes during the initial stage of acid sulfate soil formation

    NASA Astrophysics Data System (ADS)

    Gröger, J.; Hamer, K.; Schulz, H. D.

    2009-04-01

    Acid sulfate soils occur over a wide range of climatic zones, mainly in coastal landscapes. In these soils, the release of sulfuric acid by the oxidation of pyrite generates a very acidic environment (e.g., DENT and PONS, 1995, PONS, 1973). Two major types of acid sulfate soils can be distinguished: In actual acid sulfate soils, the initially contained pyrite was at least partly oxidized. This resulted in a severe acidification of the soil. Potential acid sulfate soils are generally unoxidized and contain large amounts of pyrite. Upon oxidation, these soils will turn into actual acid sulfate soils. By excavation or lowering of the groundwater table, potential acid sulfate soils can be exposed to atmospheric oxygen. During oxidation the pH drops sharply to values below pH 4. This acidification promotes the release of various metals, e.g., alumina, iron and heavy metals. Additionally, large quantities of sulfate are released. In order to assess the effects of disturbances of potential acid sulfate soils, for example by excavations during construction works, several large scale column experiments were conducted with various types of potential acid sulfate soils from Northern Germany. In these experiments, the oxidation and initial profile development of pyritic fen peats and thionic fluvisols were studied over a period of 14 months. The study focused on leaching and the translocation of various metals in the soil profile. To study mobilization processes, element fluxes and the progress of acidification, soil water and leachate were analyzed for total element concentrations. Furthermore, several redox-sensitive parameters, e.g., Fe2+ and sulfide, were measured and changes to the initial solid phase composition were analyzed. Chemical equilibria calculations of the soil water were used to gain insights into precipitation processes of secondary products of pyrite oxidation and leaching products. The results of this study will support the assessment of risks deriving from

  2. Process for removal of ammonia and acid gases from contaminated waters

    DOEpatents

    King, C.J.; Mackenzie, P.D.

    1982-09-03

    Contaminating basic gases, i.e., ammonia and acid gases, e.g., carbon dioxide, are removed from process waters or waste waters in a combined extraction and stripping process. Ammonia in the form of ammonium ion is extracted by an immiscible organic phase comprising a liquid cation exchange component, especially an organic phosphoric acid derivative, and preferably di-2-ethyl hexyl phosphoric acid, dissolved in an alkyl hydrocarbon, aryl hydrocarbon, higher alcohol, oxygenated hydrocarbon, halogenated hydrocarbon, and mixtures thereof. Concurrently, the acidic gaseous contaminants are stripped from the process or waste waters by stripping with stream, air, nitrogen, or the like. The liquid cation exchange component has the ammonia stripped therefrom by heating, and the component may be recycled to extract additional amounts of ammonia.

  3. Process for removal of ammonia and acid gases from contaminated waters

    DOEpatents

    King, C. Judson; MacKenzie, Patricia D.

    1985-01-01

    Contaminating basic gases, i.e., ammonia, and acid gases, e.g., carbon dioxide, are removed from process waters or waste waters in a combined extraction and stripping process. Ammonia in the form of ammonium ion is extracted by an immiscible organic phase comprising a liquid cation exchange component, especially an organic phosphoric acid derivative, and preferably di-2-ethyl hexyl phosphoric acid, dissolved in an alkyl hydrocarbon, aryl hydrocarbon, higher alcohol, oxygenated hydrocarbon, halogenated hydrocarbon, and mixtures thereof. Concurrently, the acidic gaseous contaminants are stripped from the process or waste waters by stripping with steam, air, nitrogen, or the like. The liquid cation exchange component has the ammonia stripped therefrom by heating, and the component may be recycled to extract additional amounts of ammonia.

  4. A novel cleaner production process of citric acid by recycling its treated wastewater.

    PubMed

    Xu, Jian; Su, Xian-Feng; Bao, Jia-Wei; Zhang, Hong-Jian; Zeng, Xin; Tang, Lei; Wang, Ke; Zhang, Jian-Hua; Chen, Xu-Sheng; Mao, Zhong-Gui

    2016-07-01

    In this study, a novel cleaner production process of citric acid was proposed to completely solve the problem of wastewater management in citric acid industry. In the process, wastewater from citric acid fermentation was used to produce methane through anaerobic digestion and then the anaerobic digestion effluent was further treated with air stripping and electrodialysis before recycled as process water for the later citric acid fermentation. This proposed process was performed for 10 batches and the average citric acid production in recycling batches was 142.4±2.1g/L which was comparable to that with tap water (141.6g/L). Anaerobic digestion was also efficient and stable in operation. The average chemical oxygen demand (COD) removal rate was 95.1±1.2% and methane yield approached to 297.7±19.8mL/g TCODremoved. In conclusion, this novel process minimized the wastewater discharge and achieved the cleaner production in citric acid industry. PMID:27054882

  5. Process and apparatus for obtaining silicon from fluosilicic acid

    DOEpatents

    Nanis, Leonard; Sanjurjo, Angel

    1986-04-22

    An apparatus for producing low cost, high purity solar grade Si wherein a reduction reaction, preferably the reduction of SiF.sub.4, by an alkali metal (Na preferred) is carried out inside a reaction chamber. The chamber wall and bottom surfaces are formed of graphite and configured with drainage channels so as to facilitate the continuous separation of the products of reaction (Si and NaF) and removal of the molten salt by discharging the salt through one or more ports at the bottom of the reaction chamber. Such process is especially useful where it is desirable to discharge the reaction salt products from the reactor and retain silicon within the chamber for later removal.

  6. Clean fuels from biomass

    NASA Technical Reports Server (NTRS)

    Hsu, Y.-Y.

    1976-01-01

    The paper discusses the U.S. resources to provide fuels from agricultural products, the present status of conversion technology of clean fuels from biomass, and a system study directed to determine the energy budget, and environmental and socioeconomic impacts. Conversion processes are discussed relative to pyrolysis and anaerobic fermentation. Pyrolysis breaks the cellulose molecules to smaller molecules under high temperature in the absence of oxygen, wheras anaerobic fermentation is used to convert biomass to methane by means of bacteria. Cost optimization and energy utilization are also discussed.

  7. Green Solvents for Precision Cleaning

    NASA Technical Reports Server (NTRS)

    Grandelli, Heather; Maloney, Phillip; DeVor, Robert; Surma, Jan; Hintze, Paul

    2013-01-01

    Aerospace machinery used in liquid oxygen (LOX) fuel systems must be precision cleaned to achieve a very low level of non-volatile residue (< 1 mg0.1 m2), especially flammable residue. Traditionally chlorofluorocarbons (CFCs) have been used in the precision cleaning of LOX systems, specifically CFC 113 (C2Cl3F3). CFCs have been known to cause the depletion of ozone and in 1987, were banned by the Montreal Protocol due to health, safety and environmental concerns. This has now led to the development of new processes in the precision cleaning of aerospace components. An ideal solvent-replacement is non-flammable, environmentally benign, non-corrosive, inexpensive, effective and evaporates completely, leaving no residue. Highlighted is a green precision cleaning process, which is contaminant removal using supercritical carbon dioxide as the environmentally benign solvent. In this process, the contaminant is dissolved in carbon dioxide, and the parts are recovered at the end of the cleaning process completely dry and ready for use. Typical contaminants of aerospace components include hydrocarbon greases, hydraulic fluids, silicone fluids and greases, fluorocarbon fluids and greases and fingerprint oil. Metallic aerospace components range from small nuts and bolts to much larger parts, such as butterfly valves 18 in diameter. A fluorinated grease, Krytox, is investigated as a model contaminant in these preliminary studies, and aluminum coupons are employed as a model aerospace component. Preliminary studies are presented in which the experimental parameters are optimized for removal of Krytox from aluminum coupons in a stirred-batch process. The experimental conditions investigated are temperature, pressure, exposure time and impeller speed. Temperatures of 308 - 423 K, pressures in the range of 8.3 - 41.4 MPa, exposure times between 5 - 60 min and impeller speeds of 0 - 1000 rpm were investigated. Preliminary results showed up to 86 cleaning efficiency with the

  8. In-silico design of computational nucleic acids for molecular information processing

    PubMed Central

    2013-01-01

    Within recent years nucleic acids have become a focus of interest for prototype implementations of molecular computing concepts. During the same period the importance of ribonucleic acids as components of the regulatory networks within living cells has increasingly been revealed. Molecular computers are attractive due to their ability to function within a biological system; an application area extraneous to the present information technology paradigm. The existence of natural information processing architectures (predominately exemplified by protein) demonstrates that computing based on physical substrates that are radically different from silicon is feasible. Two key principles underlie molecular level information processing in organisms: conformational dynamics of macromolecules and self-assembly of macromolecules. Nucleic acids support both principles, and moreover computational design of these molecules is practicable. This study demonstrates the simplicity with which one can construct a set of nucleic acid computing units using a new computational protocol. With the new protocol, diverse classes of nucleic acids imitating the complete set of boolean logical operators were constructed. These nucleic acid classes display favourable thermodynamic properties and are significantly similar to the approximation of successful candidates implemented in the laboratory. This new protocol would enable the construction of a network of interconnecting nucleic acids (as a circuit) for molecular information processing. PMID:23647621

  9. Effect of fermentation and subsequent pasteurization processes on amino acids composition of orange juice.

    PubMed

    Cerrillo, I; Fernández-Pachón, M S; Collado-González, J; Escudero-López, B; Berná, G; Herrero-Martín, G; Martín, F; Ferreres, F; Gil-Izquierdo, A

    2015-06-01

    The fermentation of fruit produces significant changes in their nutritional composition. An orange beverage has been obtained from the controlled alcoholic fermentation and thermal pasteurization of orange juice. A study was performed to determine the influence of both processes on its amino acid profile. UHPLC-QqQ-MS/MS was used for the first time for analysis of orange juice samples. Out of 29 amino acids and derivatives identified, eight (ethanolamine, ornithine, phosphoethanolamine, α-amino-n-butyric acid, hydroxyproline, methylhistidine, citrulline, and cystathionine) have not previously been detected in orange juice. The amino acid profile of the orange juice was not modified by its processing, but total amino acid content of the juice (8194 mg/L) was significantly increased at 9 days of fermentation (13,324 mg/L). Although the pasteurization process produced partial amino acid degradation, the total amino acid content was higher in the final product (9265 mg/L) than in the original juice, enhancing its nutritional value. PMID:25736875

  10. In-silico design of computational nucleic acids for molecular information processing.

    PubMed

    Ramlan, Effirul Ikhwan; Zauner, Klaus-Peter

    2013-01-01

    Within recent years nucleic acids have become a focus of interest for prototype implementations of molecular computing concepts. During the same period the importance of ribonucleic acids as components of the regulatory networks within living cells has increasingly been revealed. Molecular computers are attractive due to their ability to function within a biological system; an application area extraneous to the present information technology paradigm. The existence of natural information processing architectures (predominately exemplified by protein) demonstrates that computing based on physical substrates that are radically different from silicon is feasible. Two key principles underlie molecular level information processing in organisms: conformational dynamics of macromolecules and self-assembly of macromolecules. Nucleic acids support both principles, and moreover computational design of these molecules is practicable. This study demonstrates the simplicity with which one can construct a set of nucleic acid computing units using a new computational protocol. With the new protocol, diverse classes of nucleic acids imitating the complete set of boolean logical operators were constructed. These nucleic acid classes display favourable thermodynamic properties and are significantly similar to the approximation of successful candidates implemented in the laboratory. This new protocol would enable the construction of a network of interconnecting nucleic acids (as a circuit) for molecular information processing. PMID:23647621

  11. Cleaning up

    SciTech Connect

    Perry, T.S.

    1993-02-01

    This article reports on the electronics manufacturer's response to findings that chemicals used in manufacturing integrated circuits induced miscarriages in plant workers and other environmental problems such as ozone depletion and the use of heavy metals and toxic gases in manufacturing. The topics of the article include the finding that a photoresist is at fault, the phase-out of ethylene glycol ethers, alternatives to ethylene glycol ethers, ozone-eating CFCs, use of citrus derived substitutes for CFCs, alternative manufacturing processes, substitutes for other ozone depleting chemicals, and the use of heavy metals in electronics manufacturing.

  12. Replacement of hydrogen peroxide cleaning with oxygen plasma

    NASA Astrophysics Data System (ADS)

    Adams, B. E.

    1992-03-01

    Comparison between the standard peroxide cleaning method and an oxygen plasma modified version was run on thin film bond monitors. The plasma modified version substituted oxygen plasma for the peroxide cleaning step in the process and reduced the DI rinse water temperature from 75 C to 25 C. A direct surface cleanliness comparison was made between the two cleaning methods using Auger spectroscopy. A beam lead and ribbon bonding experiment was also run on plasma-cleaned networks. Results of both experiments indicate that plasma cleaning is superior to peroxide cleaning and that reliable bonding can be done on plasma-cleaned thin film networks.

  13. Laboratory Studies of the Tropospheric Loss Processes for Acetic and Peracetic Acid

    NASA Astrophysics Data System (ADS)

    Orlando, J. J.; Tyndall, G. S.

    2002-12-01

    Organic acids are ubiquitous components of tropospheric air and contribute to acid precipitation, particularly in remote regions. These species are present in the troposphere as the result of direct emissions from anthropogenic and biogenic sources, and as the result of photochemical processing of hydrocarbons. Production of organic acids can occur following ozonolysis of unsaturated hydrocarbons, while both organic acids and peroxyacids are formed from the reactions of HO2 with acylperoxy radicals. For example, both acetic and peracetic acid are known products of the reaction of HO2 with acetylperoxy radicals. In this paper, data relevant to the gas-phase tropospheric destruction of both acetic and peracetic acid are reported, including studies of their UV absorption spectra and of their rate coefficients for reaction with OH radicals. The data, the first of their kind for peracetic acid, show that the gas-phase lifetime of this species will be on the order of 10 days, with OH reaction occurring more rapidly than photolysis. Data on the rate coefficient for reaction of OH with acetic acid appear to resolve some conflicting data in the previous literature, and show 1) that reaction of OH with the acetic acid dimer is slow compared to the monomer and 2) that the rate coefficient possesses a negative temperature dependence near room temperature.

  14. Formic Acid Free Flowsheet Development To Eliminate Catalytic Hydrogen Generation In The Defense Waste Processing

    SciTech Connect

    Lambert, Dan P.; Stone, Michael E.; Newell, J. David; Fellinger, Terri L.; Bricker, Jonathan M.

    2012-09-14

    The Defense Waste Processing Facility (DWPF) processes legacy nuclear waste generated at the Savannah River Site (SRS) during production of plutonium and tritium demanded by the Cold War. The nuclear waste is first treated via a complex sequence of controlled chemical reactions and then vitrified into a borosilicate glass form and poured into stainless steel canisters. Converting the nuclear waste into borosilicate glass canisters is a safe, effective way to reduce the volume of the waste and stabilize the radionuclides. Testing was initiated to determine whether the elimination of formic acid from the DWPF's chemical processing flowsheet would eliminate catalytic hydrogen generation. Historically, hydrogen is generated in chemical processing of alkaline High Level Waste sludge in DWPF. In current processing, sludge is combined with nitric and formic acid to neutralize the waste, reduce mercury and manganese, destroy nitrite, and modify (thin) the slurry rheology. The noble metal catalyzed formic acid decomposition produces hydrogen and carbon dioxide. Elimination of formic acid by replacement with glycolic acid has the potential to eliminate the production of catalytic hydrogen. Flowsheet testing was performed to develop the nitric-glycolic acid flowsheet as an alternative to the nitric-formic flowsheet currently being processed at the DWPF. This new flowsheet has shown that mercury can be reduced and removed by steam stripping in DWPF with no catalytic hydrogen generation. All processing objectives were also met, including greatly reducing the Slurry Mix Evaporator (SME) product yield stress as compared to the baseline nitric/formic flowsheet. Ten DWPF tests were performed with nonradioactive simulants designed to cover a broad compositional range. No hydrogen was generated in testing without formic acid.

  15. Laboratory photochemical processing of aqueous aerosols: formation and degradation of dicarboxylic acids, oxocarboxylic acids and α-dicarbonyls

    NASA Astrophysics Data System (ADS)

    Pavuluri, C. M.; Kawamura, K.; Mihalopoulos, N.; Swaminathan, T.

    2015-07-01

    To better understand the photochemical processing of dicarboxylic acids and related polar compounds, we conducted batch UV irradiation experiments on two types of aerosol samples collected from India, which represent anthropogenic (AA) and biogenic (BA) aerosols, for time periods of 0.5 to 120 h. The irradiated samples were analyzed for molecular compositions of diacids, oxoacids and α-dicarbonyls. The results show that photochemical degradation of oxalic (C2), malonic (C3) and other C8-C12 diacids overwhelmed their production in aqueous aerosols, whereas succinic acid (C4) and C5-C7 diacids showed a significant increase (ca. 10 times) during the course of irradiation experiments. The photochemical formation of oxoacids and α-dicarbonyls overwhelmed their degradation during the early stages of experiment except for ω-oxooctanoic acid (ωC8), which showed a similar pattern to that of C4. We also found a gradual decrease in the relative abundance of C2 to total diacids and an increase in the relative abundance of C4 during prolonged experiment. Based on the changes in concentrations and mass ratios of selected species with the irradiation time, we hypothesize that iron-catalyzed photolysis of C2 and C3 diacids controls their concentrations in Fe-rich atmospheric waters, whereas photochemical formation of C4 diacid (via ωC8) is enhanced with photochemical processing of aqueous aerosols in the atmosphere. This study demonstrates that the ambient aerosols contain abundant precursors that produce diacids, oxoacids and α-dicarbonyls, although some species such as oxalic acid decompose extensively during an early stage of photochemical processing.

  16. Acid attack on hydrated cement — Effect of mineral acids on the degradation process

    SciTech Connect

    Gutberlet, T.; Hilbig, H.; Beddoe, R.E.

    2015-08-15

    During acid attack on concrete structural components, a degraded layer develops whose properties as a protective barrier are decisive for durability. {sup 29}Si NMR spectroscopy and {sup 27}Al NMR spectroscopy were used with XRD to investigate the degraded layer on hardened cement paste exposed to HCl and H{sub 2}SO{sub 4}. The layer comprises an amorphous silica gel with framework silicates, geminate and single silanol groups in which Si is substituted by Al. Amorphous Al(OH){sub 3} and Fe(OH){sub 3} are present. The gel forms by polycondensation and cross-linking of C-A-S-H chains at AlO{sub 4} bridging tetrahedra. In the transition zone between the degraded layer and the undamaged material, portlandite dissolves and Ca is removed from the C-A-S-H phases maintaining their polymer structure at first. With HCl, monosulphate in the transition zone is converted into Friedel's salt and ettringite. With H{sub 2}SO{sub 4}, gypsum precipitates near the degradation front reducing the thickness of the transition zone and the rate of degradation.

  17. Composition and process for separating cesium ions from an acidic aqueous solution also containing other ions

    DOEpatents

    Dietz, Mark L.; Horwitz, E. Philip; Bartsch, Richard A.; Barrans, Jr., Richard E.; Rausch, David

    1999-01-01

    A crown ether cesium ion extractant is disclosed as is its synthesis. The crown ether cesium ion extractant is useful for the selective purification of cesium ions from aqueous acidic media, and more particularly useful for the isolation of radioactive cesium-137 from nuclear waste streams. Processes for isolating cesium ions from aqueous acidic media using the crown ether cesium extractant are disclosed as are processes for recycling the crown ether cesium extractant and processes for recovering cesium from a crown ether cesium extractant solution.

  18. Composition and process for separating cesium ions from an acidic aqueous solution also containing other ions

    DOEpatents

    Dietz, M.L.; Horwitz, E.P.; Bartsch, R.A.; Barrans, R.E. Jr.; Rausch, D.

    1999-03-30

    A crown ether cesium ion extractant is disclosed as is its synthesis. The crown ether cesium ion extractant is useful for the selective purification of cesium ions from aqueous acidic media, and more particularly useful for the isolation of radioactive cesium-137 from nuclear waste streams. Processes for isolating cesium ions from aqueous acidic media using the crown ether cesium extractant are disclosed as are processes for recycling the crown ether cesium extractant and processes for recovering cesium from a crown ether cesium extractant solution. 4 figs.

  19. TREATMENT OF ACID MINE DRAINAGE BY THE ALUMINA-LIME-SODA PROCESS

    EPA Science Inventory

    The alumina-lime-soda process is a chemical desalination process for waters in which the principal sources of salinity are sulfate salts and has been field tested at the Commonwealth of Pennsylvania's Acid Mine Drainage Research Facility, Hollywood, Pennsylvania, as a method to r...

  20. Bacterial flora of skin of processed broilers after multiple washing in potassium hydroxide and lauric acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The number of various types of bacteria on skin of processed broilers was determined after each of five consecutive washings in mixtures of potassium hydroxide (KOH) and lauric acid (LA). Breast skin was taken from carcasses obtained from a commercial processing facility. Portions of skin were washe...

  1. Cleaning Animals' Cages With Little Water

    NASA Technical Reports Server (NTRS)

    Harman, Benjamin J.

    1989-01-01

    Proposed freeze/thaw method for cleaning animals' cages requires little extra weight and consumes little power and water. Cleaning concept developed for maintaining experimental rat cages on extended space missions. Adaptable as well to similar use on Earth. Reduces cleaning time. Makes use of already available facilities such as refrigerator, glove box, and autoclave. Rat waste adheres to steel-wire-mesh floor of cage. Feces removed by loosening action of freezing-and-thawing process, followed by blast of air.

  2. Process for enzymatic hydrolysis of fatty acid triglycerides with oat caryopses

    SciTech Connect

    Hammond, E.G.; Lee, I.

    1992-02-18

    This patent describes the process for enzymatic hydrolysis of fatty acid triglycerides to obtain free fatty acids and glycerol. It comprises: increasing the water content of dehulled whole oat caryopses to a total water content of 17 to 44% the thus moistened caryopses having active oat lipase associated with the outer surfaces thereof; contacting the moistened whole caryopses with a liquid medium, continuing the contacting until at least 20% by volume of the triglyceride reactant has been hydrolyzed to free fatty acids and glycerol, most of the free fatty acids dissolving in the oil phase external to the caryopses and most of the glycerol being absorbed into the water within the caryopses; and separating the glycerol-containing caryopses from the fatty acid-containing oil phase.

  3. Battery Technology Stores Clean Energy

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Headquartered in Fremont, California, Deeya Energy Inc. is now bringing its flow batteries to commercial customers around the world after working with former Marshall Space Flight Center scientist, Lawrence Thaller. Deeya's liquid-cell batteries have higher power capability than Thaller's original design, are less expensive than lead-acid batteries, are a clean energy alternative, and are 10 to 20 times less expensive than nickel-metal hydride batteries, lithium-ion batteries, and fuel cell options.

  4. A sulfuric-acid process with near-zero SO2 gas emissions

    NASA Astrophysics Data System (ADS)

    Jaeger, W.; Fattinger, V.; Keilpart, T.; Hamel, H.-J.

    1999-05-01

    A sulfuric-acid process has been developed that is able to handle low and variable SO2 concentrations with practically zero SO2 emissions (less than 3 ppm). The plant comprises two stages—a single-bed converter contact plant and a modified tower plant. Acids of 95 98% and/or oleum with up to 32% free SO3 can be produced in the first stage. Off-gas of the first stage is piped to the second stage, where the SO2 is converted to near nontracability while producing 76% strong acid. It is then returned to the contact plant to produce stronger acid or oleum. This process does not generate any additional disposable waste.

  5. Deriving site-specific soil clean-up values for metals and metalloids: Rationale for including protection of soil microbial processes

    PubMed Central

    Kuperman, Roman G; Siciliano, Steven D; Römbke, Jörg; Oorts, Koen

    2014-01-01

    Although it is widely recognized that microorganisms are essential for sustaining soil fertility, structure, nutrient cycling, groundwater purification, and other soil functions, soil microbial toxicity data were excluded from the derivation of Ecological Soil Screening Levels (Eco-SSL) in the United States. Among the reasons for such exclusion were claims that microbial toxicity tests were too difficult to interpret because of the high variability of microbial responses, uncertainty regarding the relevance of the various endpoints, and functional redundancy. Since the release of the first draft of the Eco-SSL Guidance document by the US Environmental Protection Agency in 2003, soil microbial toxicity testing and its use in ecological risk assessments have substantially improved. A wide range of standardized and nonstandardized methods became available for testing chemical toxicity to microbial functions in soil. Regulatory frameworks in the European Union and Australia have successfully incorporated microbial toxicity data into the derivation of soil threshold concentrations for ecological risk assessments. This article provides the 3-part rationale for including soil microbial processes in the development of soil clean-up values (SCVs): 1) presenting a brief overview of relevant test methods for assessing microbial functions in soil, 2) examining data sets for Cu, Ni, Zn, and Mo that incorporated soil microbial toxicity data into regulatory frameworks, and 3) offering recommendations on how to integrate the best available science into the method development for deriving site-specific SCVs that account for bioavailability of metals and metalloids in soil. Although the primary focus of this article is on the development of the approach for deriving SCVs for metals and metalloids in the United States, the recommendations provided in this article may also be applicable in other jurisdictions that aim at developing ecological soil threshold values for protection of

  6. Fumaric acid microenvironment tablet formulation and process development for crystalline cenicriviroc mesylate, a BCS IV compound.

    PubMed

    Menning, Mark M; Dalziel, Sean M

    2013-11-01

    Cenicriviroc mesylate (CVC) is a potent dual antagonist of C-C chemokine receptor type 5 (CCR5) and C-C chemokine receptor type 2 (CCR2) in phase 2b development as an entry inhibitor for HIV-1 infection treatment.1,2 CVC is a weak base exhibiting BCS IV characteristics with a highly pH dependent solubility profile (>100 mg/mL for pH < 2 and <0.2 μg/mL for pH > 4) and low Caco-2 cell line permeability. Previous tablet formulations of CVC, including spray-dried dispersion and a wet granulation with citric acid, had been found unacceptable for commercial use due to chemical and physical instability or unacceptably high excipient loading precluding fixed-dose combinability. A high drug loading, 26% (w/w), acidic microenvironment tablet formulation with fumaric acid solubilizer (1:1 CVC/fumaric acid) and a dry granulation process was developed iteratively through a sequence of prototypes characterized by beagle dog absorption studies, focused beam reflectance measurement (FBRM), dynamic vapor sorption (DVS), and accelerated stability testing. The fumaric acid based dry granulated product demonstrated a mean bioavailability comparable to an oral solution dose in a dog model. Stability and moisture sensitivity of the formulation were improved via the dry granulation process technique and the use of fumaric acid. It is hypothesized that the observed slow dissolution kinetics of fumaric acid prolongs an acidic microenvironment around the agglomerated CVC crystals and excipients leading to increased CVC dissolution and thereby absorption. The fumaric acid formulation also demonstrated absorption resilience to gastric pH extremes in a dog model. This optimized formulation and process enables CVC to be a viable candidate for current HIV treatment paradigms of single once daily fixed-dose combination products. PMID:23941629

  7. Selection of an acid-gas removal process for an LNG plant

    SciTech Connect

    Stone, J.B.; Jones, G.N.; Denton, R.D.

    1996-12-31

    Acid gas contaminants, such as, CO{sub 2}, H{sub 2}S and mercaptans, must be removed to a very low level from a feed natural gas before it is liquefied. CO{sub 2} is typically removed to a level of about 100 ppm to prevent freezing during LNG processing. Sulfur compounds are removed to levels required by the eventual consumer of the gas. Acid-gas removal processes can be broadly classified as: solvent-based, adsorption, cryogenic or physical separation. The advantages and disadvantages of these processes will be discussed along with design and operating considerations. This paper will also discuss the important considerations affecting the choice of the best acid-gas removal process for LNG plants. Some of these considerations are: the remoteness of the LNG plant from the resource; the cost of the feed gas and the economics of minimizing capital expenditures; the ultimate disposition of the acid gas; potential for energy integration; and the composition, including LPG and conditions of the feed gas. The example of the selection of the acid-gas removal process for an LNG plant.

  8. SODIUM ALUMINOSILICATE FOULING AND CLEANING OF DECONTAMINATED SALT SOLUTION COALESCERS

    SciTech Connect

    Poirier, M; Thomas Peters, T; Fernando Fondeur, F; Samuel Fink, S

    2008-10-28

    During initial non-radioactive operations at the Modular Caustic Side Solvent Extraction Unit (MCU), the pressure drop across the decontaminated salt solution coalescer reached {approx}10 psi while processing {approx}1250 gallons of salt solution, indicating possible fouling or plugging of the coalescer. An analysis of the feed solution and the 'plugged coalescer' concluded that the plugging was due to sodium aluminosilicate solids. MCU personnel requested Savannah River National Laboratory (SRNL) to investigate the formation of the sodium aluminosilicate solids (NAS) and the impact of the solids on the decontaminated salt solution coalescer. Researchers performed developmental testing of the cleaning protocols with a bench-scale coalescer container 1-inch long segments of a new coalescer element fouled using simulant solution. In addition, the authors obtained a 'plugged' Decontaminated Salt Solution coalescer from non-radioactive testing in the MCU and cleaned it according to the proposed cleaning procedure. Conclusions from this testing include the following: (1) Testing with the bench-scale coalescer showed an increase in pressure drop from solid particles, but the increase was not as large as observed at MCU. (2) Cleaning the bench-scale coalescer with nitric acid reduced the pressure drop and removed a large amount of solid particles (11 g of bayerite if all aluminum is present in that form or 23 g of sodium aluminosilicate if all silicon is present in that form). (3) Based on analysis of the cleaning solutions from bench-scale test, the 'dirt capacity' of a 40 inch coalescer for the NAS solids tested is calculated as 450-950 grams. (4) Cleaning the full-scale coalescer with nitric acid reduced the pressure drop and removed a large amount of solid particles (60 g of aluminum and 5 g of silicon). (5) Piping holdup in the full-scale coalescer system caused the pH to differ from the target value. Comparable hold-up in the facility could lead to less effective

  9. Current knowledge on mycolic acids in Corynebacterium glutamicum and their relevance for biotechnological processes.

    PubMed

    Lanéelle, Marie-Antoinette; Tropis, Maryelle; Daffé, Mamadou

    2013-12-01

    Corynebacterium glutamicum is the world's largest producer of glutamate and lysine. Industrial glutamate overproduction is induced by empirical processes, such as biotin limitation, supplementation with specific surfactants or addition of sublethal concentration of certain antibiotics to the culture media. Although Gram-positive bacteria, C. glutamicum and related bacterial species and genera contain, in addition to the plasma membrane, an outer permeability membrane similar to that of Gram-negative microorganisms. As the amino acids have to cross both membranes, their integrity, composition and fluidity influence the export process. While the precise mechanism of the export of the amino acids by C. glutamicum is not fully understood, the excretion of amino acids through the inner membrane involved at least a major export system mechanosensitive channel MscS family (MscCG) encoded by NCgl1221. As the various industrial treatments have been shown to affect the lipid content of the bacterial cell, it is strongly believed that defects in the hallmark of the outer membrane, 2-alkyl, 3-hydroxylated long-chain fatty acids (mycolic acids), could be key factors in the glutamate overproduction. This review aims at giving an overview of the current knowledge on mycolic acids structure, biosynthesis and transfer in C. glutamicum and their relevance for amino acid biotechnological production. PMID:24113823

  10. PROCESS OF SECURING PLUTONIUM IN NITRIC ACID SOLUTIONS IN ITS TRIVALENT OXIDATION STATE

    DOEpatents

    Thomas, J.R.

    1958-08-26

    >Various processes for the recovery of plutonium require that the plutonium be obtalned and maintained in the reduced or trivalent state in solution. Ferrous ions are commonly used as the reducing agent for this purpose, but it is difficult to maintain the plutonium in a reduced state in nitric acid solutions due to the oxidizing effects of the acid. It has been found that the addition of a stabilizing or holding reductant to such solution prevents reoxidation of the plutonium. Sulfamate ions have been found to be ideally suitable as such a stabilizer even in the presence of nitric acid.

  11. Guideline implementation: surgical instrument cleaning.

    PubMed

    Cowperthwaite, Liz; Holm, Rebecca L

    2015-05-01

    Cleaning, decontaminating, and handling instructions for instruments vary widely based on the type of instrument and the manufacturer. Processing instruments in accordance with the manufacturer's instructions can help prevent damage and keep devices in good working order. Most importantly, proper cleaning and disinfection may prevent transmission of pathogenic organisms from a contaminated device to a patient or health care worker. The updated AORN "Guideline for cleaning and care of surgical instruments" provides guidance on cleaning, decontaminating, transporting, inspecting, and storing instruments. This article focuses on key points of the guideline to help perioperative personnel implement appropriate instrument care protocols in their practice settings. The key points address timely cleaning and decontamination of instruments after use; appropriate heating, ventilation, and air conditioning parameters for the decontamination area; processing of ophthalmic instruments and laryngoscopes; and precautions to take with instruments used in cases of suspected prion disease. Perioperative RNs should review the complete guideline for additional information and for guidance when writing and updating policies and procedures. PMID:25946180

  12. Intersection of RNA Processing and the Type II Fatty Acid Synthesis Pathway in Yeast Mitochondria▿

    PubMed Central

    Schonauer, Melissa S.; Kastaniotis, Alexander J.; Hiltunen, J. Kalervo; Dieckmann, Carol L.

    2008-01-01

    Distinct metabolic pathways can intersect in ways that allow hierarchical or reciprocal regulation. In a screen of respiration-deficient Saccharomyces cerevisiae gene deletion strains for defects in mitochondrial RNA processing, we found that lack of any enzyme in the mitochondrial fatty acid type II biosynthetic pathway (FAS II) led to inefficient 5′ processing of mitochondrial precursor tRNAs by RNase P. In particular, the precursor containing both RNase P RNA (RPM1) and tRNAPro accumulated dramatically. Subsequent Pet127-driven 5′ processing of RPM1 was blocked. The FAS II pathway defects resulted in the loss of lipoic acid attachment to subunits of three key mitochondrial enzymes, which suggests that the octanoic acid produced by the pathway is the sole precursor for lipoic acid synthesis and attachment. The protein component of yeast mitochondrial RNase P, Rpm2, is not modified by lipoic acid in the wild-type strain, and it is imported in FAS II mutant strains. Thus, a product of the FAS II pathway is required for RNase P RNA maturation, which positively affects RNase P activity. In addition, a product is required for lipoic acid production, which is needed for the activity of pyruvate dehydrogenase, which feeds acetyl-coenzyme A into the FAS II pathway. These two positive feedback cycles may provide switch-like control of mitochondrial gene expression in response to the metabolic state of the cell. PMID:18779316

  13. Comparative metabolomics analysis of docosahexaenoic acid fermentation processes by Schizochytrium sp. under different oxygen availability conditions.

    PubMed

    Li, Juan; Ren, Lu-Jing; Sun, Guan-Nan; Qu, Liang; Huang, He

    2013-05-01

    The intracellular metabolic profile characterization of Schizochytrium sp. throughout docosahexaenoic acid fermentation was investigated using gas chromatography-mass spectrometry (GC-MS). Metabolite profiles originating from Schizochytrium sp. under normal and limited oxygen supply conditions were distinctive and distinguished by principal components analysis (PCA). A total of more than 60 intracellular metabolites were detected and quantified with the levels of some metabolites involved in central carbon metabolism varying throughout both processes. Both fermentation processes were differentiated into three main phases by principal components analysis. Potential biomarkers responsible for distinguishing the different fermentation phases were identified as glutamic acid, proline, glycine, alanine, and glucose. In addition, alanine, glutamic acid, glucose, inositol, ornithine, and galactose were found to make great contribution for dry cell weight and fatty acid composition during normal and limited oxygen supply fermentations. Furthermore, significantly higher levels of succinate and several amino acids in cells of limited oxygen supply fermentation revealed that they might play important roles in resisting oxygen deficiency and increasing DHA synthesis during the lipid accumulation. These findings provide novel insights into the metabolomic characteristics during docosahexaenoic acid fermentation processes by Schizochytrium sp. PMID:23586678

  14. Application of hydrogenation to low-temperature cleaning of the Si(001) surface in the processes of molecular-beam epitaxy: Investigation by scanning tunneling microscopy, reflected high-energy electron diffraction, and high resolution transmission electron microscopy

    SciTech Connect

    Arapkina, L. V.; Krylova, L. A.; Chizh, K. V.; Chapnin, V. A.; Uvarov, O. V.; Yuryev, V. A.

    2012-07-01

    Structural properties of the clean Si(001) surface obtained as a result of low-temperature (470-650 Degree-Sign C) pre-growth annealings of silicon wafers in a molecular-beam epitaxy chamber have been investigated. To decrease the cleaning temperature, a silicon surface was hydrogenated in the process of a preliminary chemical treatment in HF and NH{sub 4}F aqueous solutions. It has been shown that smooth surfaces composed of wide terraces separated by monoatomic steps can be obtained by dehydrogenation at the temperatures Greater-Than-Or-Equivalent-To 600 Degree-Sign C, whereas clean surfaces obtained at the temperatures <600 Degree-Sign C are rough. It has been found that there exists a dependence of structural properties of clean surfaces on the temperature of hydrogen thermal desorption and the process of the preliminary chemical treatment. The frequency of detachment/attachment of Si dimers from/to the steps and effect of the Ehrlich-Schwoebel barrier on ad-dimer migration across steps have been found to be the most probable factors determining a degree of the resultant surface roughness.

  15. High throughput determination of cleaning solutions to prevent the fouling of an anion exchange resin.

    PubMed

    Elich, Thomas; Iskra, Timothy; Daniels, William; Morrison, Christopher J

    2016-06-01

    Effective cleaning of chromatography resin is required to prevent fouling and maximize the number of processing cycles which can be achieved. Optimization of resin cleaning procedures, however, can lead to prohibitive material, labor, and time requirements, even when using milliliter scale chromatography columns. In this work, high throughput (HT) techniques were used to evaluate cleaning agents for a monoclonal antibody (mAb) polishing step utilizing Fractogel(®) EMD TMAE HiCap (M) anion exchange (AEX) resin. For this particular mAb feed stream, the AEX resin could not be fully restored with traditional NaCl and NaOH cleaning solutions, resulting in a loss of impurity capacity with resin cycling. Miniaturized microliter scale chromatography columns and an automated liquid handling system (LHS) were employed to evaluate various experimental cleaning conditions. Cleaning agents were monitored for their ability to maintain resin impurity capacity over multiple processing cycles by analyzing the flowthrough material for turbidity and high molecular weight (HMW) content. HT experiments indicated that a 167 mM acetic acid strip solution followed by a 0.5 M NaOH, 2 M NaCl sanitization provided approximately 90% cleaning improvement over solutions containing solely NaCl and/or NaOH. Results from the microliter scale HT experiments were confirmed in subsequent evaluations at the milliliter scale. These results identify cleaning agents which may restore resin performance for applications involving fouling species in ion exchange systems. In addition, this work demonstrates the use of miniaturized columns operated with an automated LHS for HT evaluation of chromatographic cleaning procedures, effectively decreasing material requirements while simultaneously increasing throughput. Biotechnol. Bioeng. 2016;113: 1251-1259. © 2015 Wiley Periodicals, Inc. PMID:26552005

  16. What Is Clean Cities?

    SciTech Connect

    Not Available

    2007-08-01

    This Clean Cities Program fact sheet describes the purpose and scope of this DOE program. Clean Cities facilitates the use of alternative and advanced fuels and vehicles to displace petroleum in the transportation sector.

  17. Twelve Home Cleaning Recipes

    MedlinePlus

    ... for Safe and Effective Disinfection Twelve Home Cleaning Recipes Safer alternatives to hazardous cleaning products exist for ... 24 hours at room temperature. All Purpose Cleaner recipes for use on counters, floors and other hard ...

  18. Process development for the biological production of succinic acid and its derivatives from renewables

    SciTech Connect

    Davison, B.H.; Nghiem, N.P.

    1995-12-01

    The initial targets of the Alternative Feedstocks Program (AFP) are succinic acid and its derivatives. The first goal is to develop and demonstrate an integrated process for succinic acid production from renewable materials such as corn dextrose. A process has been identified to produce succinic acid by fermentation, purify it without precipitation, and convert it as an ester to butanediol. Four areas have been identified for improvement by focused research and development. These include (1) biocatalyst improvements through metabolic engineering, (2) bioreactor design, (3) separation/purification of succinic acid by membrane electrodialysis or adsorption, and (4) catalytic conversion of succinic acid to higher-valued chemicals such as butanediol. An essential element in this program is the on-going effort in process design, integration and economic assessment to evaluate the current process and the potential impacts of the proposed improvements. The AFP, which focuses on renewables-to-chemicals opportunities, is a joint effort between industry and a national laboratory team consisting of the National Renewable Energy Laboratory, Argonne National Laboratory, Idaho National Engineering Laboratory, Oak Ridge National Laboratory and Pacific Northwest Laboratory Michigan Biotechnology Institute is a collaborator on the succinic project.

  19. Cleaning laser spark spectroscopy for online cleaning quality control method development

    NASA Astrophysics Data System (ADS)

    Mutin, T. Y.; Smirnov, V. N.; Veiko, V. P.; Volkov, S. A.

    2010-07-01

    This work is dedicated to spectroscopic investigations of laser spark during the laser cleaning process. The goal is to proof its analytical possibilities for chemical composition determination for online cleaning quality control. Photographic recordings of laser spark were performed to estimate its parameters. Fiber spectrometer was used to analyze the emission of cleaning process established with fiber laser. Conclusions have been made about fiber laser radiation usability for spectroscopic purpose.

  20. Cleaning laser spark spectroscopy for online cleaning quality control method development

    NASA Astrophysics Data System (ADS)

    Mutin, T. Y.; Smirnov, V. N.; Veiko, V. P.; Volkov, S. A.

    2011-02-01

    This work is dedicated to spectroscopic investigations of laser spark during the laser cleaning process. The goal is to proof its analytical possibilities for chemical composition determination for online cleaning quality control. Photographic recordings of laser spark were performed to estimate its parameters. Fiber spectrometer was used to analyze the emission of cleaning process established with fiber laser. Conclusions have been made about fiber laser radiation usability for spectroscopic purpose.