MODULAR CAUSTIC SIDE SOLVENT EXTRACTION UNIT (MCU) GAMMA MONITORS SYSTEM FINAL REPORT

International Nuclear Information System (INIS)

Casella, V

2005-01-01

The Department of Energy (DOE) selected Caustic-Side Solvent Extraction (CSSX) as the preferred technology for the removal of radioactive cesium from High-Level Waste (HLW) at the Savannah River Site (SRS). Before the full-scale Salt Waste Processing Facility (SWPF) becomes operational, the Closure Business Unit (CBU) plans to process a portion of dissolved saltcake waste through a Modular CSSX Unit (MCU). This work was derived from Technical Task Request SP-TTR-2004-00013, ''Gamma Monitor for MCU''. The deliverables for this task are the hardware and software for the gamma monitors and a report summarizing the testing and acceptance of this equipment for use in the MCU. Gamma-ray monitors are required to: (1) Measure the Cs-137 concentration in the decontaminated salt solution before entering the DSS (Decontaminated Salt Solution) Hold Tank, (2) Measure the Cs-137 concentration in the strip effluent before entering the Strip Effluent Hold Tank, (3) Verify proper operation of the solvent extraction system by verifying material balance within the process (The DSS Hold Tank Cs-137 concentration will be very low and the Cs-137 concentration in the Strip Effluent Hold Tank will be fifteen times higher than the Cs-137 concentration in the Feed Tank.) Sodium iodide monitors are used to measure the Cs-137 concentration in the piping before the DSS Hold tank, while GM monitors are used for Cs-137 measurements before the Strip Effluent Hold Tank. Tungsten shields were designed using Monte Carlo calculations and fabricated to reduce the process background radiation at the detector positions. These monitors were calibrated with NIST traceable standards that were specially made to be the same as the piping being monitored. Since this gamma ray monitoring system is unique, specially designed software was written and acceptance tested by Savannah River National Laboratory personnel. The software is a LabView-based application that serves as a unified interface for controlling

Catalog solvent extraction: anticipate process adjustments

International Nuclear Information System (INIS)

Campbell, S.G.; Brass, E.A.; Brown, S.J.; Geeting, M.W.

2008-01-01

The Modular Caustic-Side Solvent Extraction Unit (MCU) utilizes commercially available centrifugal contactors to facilitate removal of radioactive cesium from highly alkaline salt solutions. During the fabrication of the contactor assembly, demonstrations revealed a higher propensity for foaming than was initially expected. A task team performed a series of single-phase experiments that revealed that the shape of the bottom vanes and the outer diameter of those vanes are key to the successful deployment of commercial contactors in the Caustic-Side Solvent Extraction Process. (authors)

Partitioning of Tank Waste Sludge in a 5-cm Centrifugal Contactor Under Caustic-Side Solvent Extraction Conditions

International Nuclear Information System (INIS)

Birdwell, Jr. J.F.

2001-01-01

A test program has been performed to evaluate the effect of solids on the hydraulic performance of a 5-cm centrifugal contactor under conditions present in the extraction section of the Caustic-Side Solvent Extraction (CSSX) process. In addition to determining if the ability to separate the aqueous and organic phases is affected by the presence of solids in a feed solution, the extent to which solids are accumulated in the contactor was also assessed. The reported task was motivated by the need to determine if removal of cesium from Savannah River Site tank waste can be performed using a contactor-based CSSX process without first removing sludge that is suspended in the feed solution. The ability to pass solids through the CSSX process could facilitate placement of CSSX upstream of a process in which alpha-decaying actinides and strontium are removed from the waste stream by precipitation with monosodium titanate (MST). This relative placement of the CSSX and MST processes is desirable because removal of cesium would greatly reduce the activity level of the feed stream to the MST process, thereby reducing the level of shielding needed and mitigating remote maintenance design features of MST equipment. Both results would significantly reduce the cost of the Salt Processing Project. Test results indicate conclusively that a large fraction of suspended sludge that enters the centrifugal contactor remains inside. It is expected that extended operation would result in continued accumulation of solids and that hydraulic performance would be adversely affected. Results also indicate that a fraction of the solids partitions to the phase boundary and could affect phase separation as contactor operations progress

DWPF Flowsheet Studies with Simulants to Determine Modular Caustic Side Solvent Extraction Unit Solvent Partitioning and Verify Actinide Removal Process Incorporation Strategy

International Nuclear Information System (INIS)

Herman, C

2006-01-01

The Actinide Removal Process (ARP) facility and the Modular Caustic Side Solvent Extraction Unit (MCU) are scheduled to begin processing salt waste in fiscal year 2007. A portion of the streams generated in the salt processing facilities will be transferred to the Defense Waste Processing Facility (DWPF) to be incorporated in the glass matrix. Before the streams are introduced, a combination of impact analyses and research and development studies must be performed to quantify the impacts on DWPF processing. The Process Science and Engineering (PS and E) section of the Savannah River National Laboratory (SRNL) was requested via Technical Task Request (TTR) HLW/DWPF/TTR-2004-0031 to evaluate the impacts on DWPF processing. Simulant Chemical Process Cell (CPC) flowsheet studies have been performed using previous composition and projected volume estimates for the ARP sludge/monosodium titanate (MST) stream. Due to changes in the flammability control strategy for DWPF for salt processing, the incorporation strategy for ARP has changed and additional ARP flowsheet tests were necessary to validate the new processing strategy. The last round of ARP testing included the incorporation of the MCU stream and identified potential processing issues with the MCU solvent. The identified issues included the potential carry-over and accumulation of the MCU solvent components in the CPC condensers and in the recycle stream to the Tank Farm. Therefore, DWPF requested SRNL to perform additional MCU flowsheet studies to better quantify the organic distribution in the CPC vessels. The previous MCU testing used a Sludge Batch 4 (SB4) simulant since it was anticipated that both of these facilities would begin salt processing during SB4 processing. The same sludge simulant recipe was used in this round of ARP and MCU testing to minimize the number of changes between the two phases of testing so a better comparison could be made. ARP and MCU stream simulants were made for this phase of

Using GC-FID to Quantify the Removal of 4-sec-Butylphenol from NGS Solvent by NaOH

Energy Technology Data Exchange (ETDEWEB)

Sloop, Jr., Frederick V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Moyer, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2014-12-01

A caustic wash of the solvent used in the Next-Generation Caustic-Side Solvent Extraction (NG-CSSX) process was found to remove the modifier breakdown product 4-sec-butylphenol (SBP) with varying efficiency depending on the aqueous NaOH concentration. Recent efforts at ORNL have aimed at characterizing the flowsheet chemistry and reducing the technical uncertainties of the NG-CSSX process. One technical uncertainty has been the efficacy of caustic washing of the solvent for the removal of lipophilic anions, in particular, the efficient removal of SBP, an important degradation product of the solvent modifier, Cs-7SB. In order to make this determination, it was necessary to develop a sensitive and reliable analytical technique for the detection and quantitation of SBP. This report recounts the development of a GC-FID-based (Gas Chromatography Flame Ionization Detection) technique for analyzing SBP and the utilization of the technique to subsequently confirm the ability of the caustic wash to efficiently remove SBP from the Next Generation Solvent (NGS) used in NG-CSSX. In particular, the developed technique was used to monitor the amount of SBP removed from a simple solvent and the full NGS by contact with sodium hydroxide wash solutions over a range of concentrations. The results show that caustic washing removes SBP with effectively the same efficiency as it did in the original Caustic-Side Solvent Extraction (CSSX) process.

SOLVENT FIRE BY-PRODUCTS

Energy Technology Data Exchange (ETDEWEB)

Walker, D; Samuel Fink, S

2006-05-22

Southwest Research Institute (SwRI) conducted a burn test of the Caustic-Side Solvent Extraction (CSSX) solvent to determine the combustion products. The testing showed hydrogen fluoride gas is not a combustion product from a solvent fire when up to 70% of the solvent is consumed. The absence of HF in the combustion gases may reflect concentration of the modifier containing the fluoride groups in the unburned portion. SwRI reported results for other gases (CO, HCN, NOx, formaldehyde, and hydrocarbons). The results, with other supporting information, can be used for evaluating the consequences of a facility fire involving the CSSX solvent inventory.

Caustic-Side Solvent Extraction: Anti-Caking Surfactants Found to be Cause of Apparent Effect of High Nitrite Concentration on Cesium Stripping

Energy Technology Data Exchange (ETDEWEB)

Delmau, L.H.

2002-06-13

Experiments conducted in FY01 previously indicated a potential cesium stripping problem in the CSSX process due to the presence of nitrite in the waste simulant. The stripping issue seemed all the more important as the nitrite concentration increased. Experiments presented in this work have demonstrated that the true reason for the cesium stripping problem was in fact the presence of an anti-caking agent in the,sodium nitrite. used for the preparation of the simulants. The anti-caking agent is actually a mixture of well-known surfactants, sodium mono- and di-methyl naphthalene sulfonate that can partition into the organic-phase on extraction, then retain cesium upon stripping. The effect was demonstrated by adding known amounts of the anti-caking agent to clean systems. Data suggest that rejuvenation of the solvent can be obtained by a caustic wash following the stripping stage.

DEMONSTRATION OF THE NEXT-GENERATION CAUSTIC-SIDE SOLVENT EXTRACTION SOLVENT WITH 2-CM CENTRIFUGAL CONTRACTORS USING TANK 49H WASTE AND WASTE SIMULANT

Energy Technology Data Exchange (ETDEWEB)

Pierce, R.; Peters, T.; Crowder, M.; Caldwell, T.; Pak, D; Fink, S.; Blessing, R.; Washington, A.

2011-09-27

Researchers successfully demonstrated the chemistry and process equipment of the Caustic-Side Solvent Extraction (CSSX) flowsheet using MaxCalix for the decontamination of high level waste (HLW). The demonstration was completed using a 12-stage, 2-cm centrifugal contactor apparatus at the Savannah River National Laboratory (SRNL). This represents the first CSSX process demonstration of the MaxCalix solvent system with Savannah River Site (SRS) HLW. Two tests lasting 24 and 27 hours processed non-radioactive simulated Tank 49H waste and actual Tank 49H HLW, respectively. Conclusions from this work include the following. The CSSX process is capable of reducing {sup 137}Cs in high level radioactive waste by a factor of more than 40,000 using five extraction, two scrub, and five strip stages. Tests demonstrated extraction and strip section stage efficiencies of greater than 93% for the Tank 49H waste test and greater than 88% for the simulant waste test. During a test with HLW, researchers processed 39 liters of Tank 49H solution and the waste raffinate had an average decontamination factor (DF) of 6.78E+04, with a maximum of 1.08E+05. A simulant waste solution ({approx}34.5 liters) with an initial Cs concentration of 83.1 mg/L was processed and had an average DF greater than 5.9E+03, with a maximum DF of greater than 6.6E+03. The difference may be attributable to differences in contactor stage efficiencies. Test results showed the solvent can be stripped of cesium and recycled for {approx}25 solvent turnovers without the occurrence of any measurable solvent degradation or negative effects from minor components. Based on the performance of the 12-stage 2-cm apparatus with the Tank 49H HLW, the projected DF for MCU with seven extraction, two scrub, and seven strip stages operating at a nominal efficiency of 90% is {approx}388,000. At 95% stage efficiency, the DF in MCU would be {approx}3.2 million. Carryover of organic solvent in aqueous streams (and aqueous in organic

Development of Effective Solvent Modifiers for the Solvent Extraction of Cesium from Alkaline High-Level Tank Waste

International Nuclear Information System (INIS)

Bonnesen, Peter V.; Delmau, Laetitia H.; Moyer, Bruce A.; Lumetta, Gregg J.

2003-01-01

A series of novel alkylphenoxy fluorinated alcohols were prepared and investigated for their effectiveness as modifiers in solvents containing calix(4)arene-bis-(tert-octylbenzo)-crown-6 for extracting cesium from alkaline nitrate media. A modifier that contained a terminal 1,1,2,2-tetrafluoroethoxy group was found to decompose following long-term exposure to warm alkaline solutions. However, replacement of the tetrafluoroethoxy group with a 2,2,3,3-tetrafluoropropoxy group led to a series of modifiers that possessed the alkaline stability required for a solvent extraction process. Within this series of modifiers, the structure of the alkyl substituent (tert-octyl, tert-butyl, tert-amyl, and sec-butyl) of the alkylphenoxy moiety was found to have a profound impact on the phase behavior of the solvent in liquid-liquid contacting experiments, and hence on the overall suitability of the modifier for a solvent extraction process. The sec-butyl derivative(1-(2,2,3,3-tetrafluoropropoxy)-3- (4-sec-butylphenoxy)-2-propanol) (Cs-7SB) was found to possess the best overall balance of properties with respect to third phase and coalescence behavior, cleanup following degradation, resistance to solids formation, and cesium distribution behavior. Accordingly, this modifier was selected for use as a component of the solvent employed in the Caustic-Side Solvent Extraction (CSSX) process for removing cesium from high level nuclear waste (HLW) at the U.S. Department of Energy's (DOE) Savannah River Site. In batch equilibrium experiments, this solvent has also been successfully shown to extract cesium from both simulated and actual solutions generated from caustic leaching of HLW tank sludge stored in tank B-110 at the DOE's Hanford Site.

Effect of heating rate on caustic stress corrosion cracking

International Nuclear Information System (INIS)

Indig, M.E.; Hoffman, N.J.

1977-01-01

To evaluate effects of a large water leak into the sodium side of a steam generator in a Liquid Metal Fast Breeder Reactor the Liquid Metal Engineering Center (LMEC) at Canoga Park, California, is performing a series of tests in a Large Leak Test Rig (LLTR). This test series involves heating a large steam generator that possibly contains localized pockets of aqueous caustic retained from a previous sodium-water reaction. Such pockets of caustic solution could be in contact with welds and other components that contain residual stresses up to the yield point. The LMEC and General Electric (GE) ran a series of tests to evaluate the effect of heating rate on caustic stress corrosion cracking (SCC) for alloys either used or considered for the LLTR. A summary of the temperatures and caustic concentration ranges that can result in caustic SCC for carbon steel and Type-304 stainless steel is given

Results Of The Extraction-Scrub-Strip Testing Using An Improved Solvent Formulation And Salt Waste Processing Facility Simulated Waste

International Nuclear Information System (INIS)

Peters, T.; Washington, A.; Fink, S.

2012-01-01

The Office of Waste Processing, within the Office of Technology Innovation and Development, is funding the development of an enhanced solvent - also known as the next generation solvent (NGS) - for deployment at the Savannah River Site to remove cesium from High Level Waste. The technical effort is a collaborative effort between Oak Ridge National Laboratory (ORNL) and Savannah River National Laboratory (SRNL). As part of the program, the Savannah River National Laboratory (SRNL) has performed a number of Extraction-Scrub-Strip (ESS) tests. These batch contact tests serve as first indicators of the cesium mass transfer solvent performance with actual or simulated waste. The test detailed in this report used simulated Tank 49H material, with the addition of extra potassium. The potassium was added at 1677 mg/L, the maximum projected (i.e., a worst case feed scenario) value for the Salt Waste Processing Facility (SWPF). The results of the test gave favorable results given that the potassium concentration was elevated (1677 mg/L compared to the current 513 mg/L). The cesium distribution value, DCs, for extraction was 57.1. As a comparison, a typical D Cs in an ESS test, using the baseline solvent formulation and the typical waste feed, is ∼15. The Modular Caustic Side Solvent Extraction Unit (MCU) uses the Caustic-Side Solvent Extraction (CSSX) process to remove cesium (Cs) from alkaline waste. This process involves the use of an organic extractant, BoBCalixC6, in an organic matrix to selectively remove cesium from the caustic waste. The organic solvent mixture flows counter-current to the caustic aqueous waste stream within centrifugal contactors. After extracting the cesium, the loaded solvent is stripped of cesium by contact with dilute nitric acid and the cesium concentrate is transferred to the Defense Waste Processing Facility (DWPF), while the organic solvent is cleaned and recycled for further use. The Salt Waste Processing Facility (SWPF), under

Dark Matter Caustics

International Nuclear Information System (INIS)

Natarajan, Aravind

2010-01-01

The continuous infall of dark matter with low velocity dispersion in galactic halos leads to the formation of high density structures called caustics. Dark matter caustics are of two kinds : outer and inner. Outer caustics are thin spherical shells surrounding galaxies while inner caustics have a more complicated structure that depends on the dark matter angular momentum distribution. The presence of a dark matter caustic in the plane of the galaxy modifies the gas density in its neighborhood which may lead to observable effects. Caustics are also relevant to direct and indirect dark matter searches.

Extraction, scrub, and strip test results for the solvent transfer to salt waste processing facility

Energy Technology Data Exchange (ETDEWEB)

Peters, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-09-07

The Savannah River National Laboratory (SRNL) prepared approximately 240 gallons of Caustic-Side Solvent Extraction (CSSX) solvent for use at the Salt Waste Processing Facility (SWPF). An Extraction, Scrub, and Strip (ESS) test was performed on a sample of the prepared solvent using a salt solution prepared by Parsons to determine cesium distribution ratios (D(Cs)), and cesium concentration in the strip effluent (SE) and decontaminated salt solution (DSS) streams. This data will be used by Parsons to help qualify the solvent for use at the SWPF. The ESS test showed acceptable performance of the solvent for extraction, scrub, and strip operations. The extraction D(Cs) measured 15.5, exceeding the required value of 8. This value is consistent with results from previous ESS tests using similar solvent formulations. Similarly, scrub and strip cesium distribution ratios fell within acceptable ranges.

Concentrating on caustic

International Nuclear Information System (INIS)

Collins, Richard

2010-01-01

in the chosen medium (wastewater) and passes electrons freed up in the process around a circuit from the anode side to the cathode, generating electricity. The protons diffuse through the liquid and a membrane to the cathode, where they re-bond with the electrons and oxygen to create water, keeping the entire system neutral. Use wastewater as the medium though, and the high levels of sodium means that rather than the protons, sodium is preferentially transferred to the cathode, preventing the full reduction of oxygen to water. Instead, hydroxyl (OH) is created, which then bonds with the sodium to create sodium hydroxide (NaOH) in a continuous process. Unlike with the electricity generation trials, the theoretical capacity of the bioelectrochemical system to produce sodium hydroxide is compelling and cost-effective. “The process is pretty successful thus far. Per kilogram of organics we remove in an anode, we can think about 5kg of caustic soda on the cathode side,” said Dr Rabeay. “You need a very small number of electrons to make sodium hydroxide and the organic matter contains a lot of electrons, it is very electron-rich.” While recovery rates will vary case by case, depending on factors such as the water parameters and how companies drive their production processes, a model wastewater containing 3kg of organics and 2kg of sodium per m"3 could remove about 0.5kg of the organics, producing 2.5kg of sodium hydroxide and removing 1.44kg of sodium from the waste stream. For a pulp and paper plant, Dr Rabaey reckons 5-10 per cent of the typical organic load could provide all the site's sodium hydroxide demand. Most industries he's studied have more than enough wastewater organics to become self-sufficient in sodium hydroxide. In 2008, he co-founded Bilexys, a spin-off company from the University of Queensland aiming to commercialise the technology for recovery of caustic and, down the track, hydrogen peroxide. Early next year, Bilexys will be building a pilot

Analysis of cesium extracting solvent using GCMS and HPLC

International Nuclear Information System (INIS)

White, T.L.; Herman, C.C.; Crump, S.L.; Marinik, A.R.; Lambert, D.P.; Eibling, R.E.

2007-01-01

A high-level waste (HLW) remediation process scheduled to begin in 2007 at the Savannah River Site is the Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU). The MCU will use a hydrocarbon solvent (diluent) containing a cesium extractant, a calix[4]arene compound, to extract radioactive cesium from caustic HLW. The resulting decontaminated HLW waste or raffinate will be processed into grout at the Saltstone Production Facility (SPF). The cesium containing CSSX stream will undergo washing with dilute nitric acid followed by stripping of the cesium nitrate into a very dilute nitric acid or the strip effluent stream and the CSSX solvent will be recycled. The Defense Waste Processing Facility (DWPF) will receive the strip effluent stream and immobilize the cesium into borosilicate glass. Excess CSSX solvent carryover from the MCU creates a potential flammability problem during DWPF processing. Bench-scale DWPF process testing was performed with simulated waste to determine the fate of the CSSX solvent components. A simple high performance liquid chromatography (HPLC) method was developed to identify the modifier (which is used to increase Cs extraction and extractant solubility) and extractant within the DWPF process. The diluent and trioctylamine (which is used to suppress impurity effect and ion-pair disassociation) were determined using gas chromatography mass spectroscopy (GCMS). To close the organic balance, two types of sample preparation methods were needed. One involved extracting aqueous samples with methylene chloride or hexane, and the second was capturing the off gas of the DWPF process using carbon tubes and rinsing the tubes with carbon disulfide for analysis. This paper addresses the development of the analytical methods and the bench-scale simulated waste study results. (author)

In-situ caustic generation from sewage: the impact of caustic strength and sewage composition.

Science.gov (United States)

Pikaar, Ilje; Rozendal, René A; Rabaey, Korneel; Yuan, Zhiguo

2013-10-01

Periodic caustic dosage is a commonly used method by the water industry to elevate pH levels and deactivate sewer biofilms responsible for hydrogen sulfide generation. Caustic (NaOH) can be generated in-situ from sewage using a divided electrochemical cell, which avoids the need for transport, handling and storage of concentrated caustic solutions. In this study, we investigated the impact of caustic strength in the cathode compartment and the impact of sodium concentration in sewage on the Coulombic efficiency (CE) for caustic generation. The CE was found to be independent of the caustic strength produced in the range of up to ~3 wt%. Results showed that a caustic solution of ~3 wt% could be produced directly from sewage at a CE of up to 75 ± 0.5%. The sodium concentration in sewage had a significant impact on the CE for caustic generation as well as on the energy requirements of the system, with a higher sodium concentration leading to a higher CE and lower energy consumption. The proton, calcium, magnesium and ammonium concentrations in sewage affected the CE for caustic generation, especially at low sodium concentrations. Economical assessment based on the experimental results indicated that sulfide control in sewers using electrochemically-generated caustic from sewage is an economically attractive strategy. Copyright © 2013 Elsevier Ltd. All rights reserved.

Extracting solid carbonaceous materials with solvents

Energy Technology Data Exchange (ETDEWEB)

1936-02-08

Solvent extraction of solid carbonaceous materials is performed in the presence of powdered catalysts together with alkaline substances. Oxides of nickel or iron or nickel nitrate have been used together with caustic soda or potash solutions or milk of lime. Solvents used include benzenes, middle oils, tars, tetrahydronaphthalene. The extraction is performed at 200 to 500/sup 0/C under pressures of 20 to 200 atm. Finely ground peat was dried and mixed with milk of lime and nickel nitrate and an equal quantity of middle oil. The mixture was heated for 3 h at 380/sup 0/C at 90 atm. 88.5% of the peat was extracted. In a similar treatment brown coal was impregnated with solutions of caustic soda and ferric chloride.

Solvent Exchange Rates of Side-chain Amide Protons in Proteins

International Nuclear Information System (INIS)

Rajagopal, Ponni; Jones, Bryan E.; Klevit, Rachel E.

1998-01-01

Solvent exchange rates and temperature coefficients for Asn/Gln side-chain amide protons have been measured in Escherichia coli HPr. The protons of the eight side-chain amide groups (two Asn and six Gln) exhibit varying exchange rates which are slower than some of the fast exchanging backbone amide protons. Differences in exchange rates of the E and Z protons of the same side-chain amide group are obtained by measuring exchange rates at pH values > 8. An NOE between a side-chain amide proton and a bound water molecule was also observed

Solvent Carryover Characterization and Recovery for a 10-inch Single Stage Centrifugal Contactor

International Nuclear Information System (INIS)

Lentsch, R.D.; Stephens, A.B.; Leung, D.T.; Baffling, K.E.; Harmon, H.D.; Suggs, P.C.

2006-01-01

A test program has been performed to characterize the organic solvent carryover and recovery from centrifugal contactors in the Caustic-side Solvent Extraction (CSSX) process. CSSX is the baseline design for removing cesium from salt solutions for Department of Energy (DOE) Savannah River Site's Salt Waste Processing Facility. CSSX uses a custom solvent to extract cesium from the salt solution in a series of single stage centrifugal contactors. Meeting the Waste Acceptance Criteria at the Defense Waste Processing Facility and Saltstone, as well as plant economics, dictate that solvent loss should be kept to a minimum. Solvent droplet size distribution in the aqueous outlet streams of the CSSX contactors is of particular importance to the design of solvent recovery equipment. Because insufficient solvent droplet size data existed to form a basis for the recovery system design, DOE funded the CSSX Solvent Carryover Characterization and Recovery Test (SCCRT). This paper presents the droplet size distribution of solvent and concentration in the contactor aqueous outlet streams as a function of rotor speed, bottom plate type, and flow rate. It also presents the performance data of a prototype coalescer. (authors)

Caustics and Caustic-Interference in Measurements of Contact Angle and Flow Visualization Through Laser Shadowgraphy

Science.gov (United States)

Chao, David F.; Zhang, Neng-Li

2002-01-01

As one of the basic elements of the shadowgraphy optical system, the image of the far field from the droplet implicates plentiful information on the droplet profile. An analysis of caustics by wave theory shows that a droplet with a cylindrically symmetric Gaussian-hill-type profile produces a circular directional caustic in far field, which arises from the singularities (inflection line on the surface). The sessile liquid droplets, which profiles are restricted by surface tension, usually have a 'protruding foot' where the surface inflects. Simple geometrical optics indicates that the circular caustic stemming from the surface inflection at the protruding-foot takes the shape of the outmost ring on the image of the far field. It is the diameter of the outmost ring that is used as one of the key parameters in the measurements of contact angle through the laser shadowgraphic method. Different surface characteristics of the droplets produce different type of caustics, and therefore, the shape of the caustics can be used to determine the surface property of the sessile droplets. The present paper describes the measurement method of contact angIe using the circular caustics and the estimation of the protruding-foot height through the caustic interference.

Causticizing for Black Liquor Gasifiers

Energy Technology Data Exchange (ETDEWEB)

Scott Sinquefeld; James Cantrell; Xiaoyan Zeng; Alan Ball; Jeff Empie

2009-01-07

The cost-benefit outlook of black liquor gasification (BLG) could be greatly improved if the smelt causticization step could be achieved in situ during the gasification step. Or, at a minimum, the increase in causticizing load associated with BLG could be mitigated. A number of chemistries have been proven successful during black liquor combustion. In this project, three in situ causticizing processes (titanate, manganate, and borate) were evaluated under conditions suitable for high temperature entrained flow BLG, and low temperature steam reforming of black liquor. The evaluation included both thermodynamic modeling and lab experimentation. Titanate and manganate were tested for complete direct causticizing (to thus eliminate the lime cycle), and borates were evaluated for partial causticizing (to mitigate the load increase associated with BLG). Criteria included high carbonate conversion, corresponding hydroxide recovery upon hydrolysis, non process element (NPE) removal, and economics. Of the six cases (three chemistries at two BLG conditions), only two were found to be industrially viable: titanates for complete causticizing during high temperature BLG, and borates for partial causticizing during high temperature BLG. These two cases were evaluated for integration into a gasification-based recovery island. The Larsen [28] BLG cost-benefit study was used as a reference case for economic forecasting (i.e. a 1500 tpd pulp mill using BLG and upgrading the lime cycle). By comparison, using the titanate direct causticizing process yielded a net present value (NPV) of $25M over the NPV of BLG with conventional lime cycle. Using the existing lime cycle plus borate autocausticizing for extra capacity yielded a NPV of $16M.

Analytical Methods for Cs-137 and Other Radionuclides in Solvent Samples

International Nuclear Information System (INIS)

Pennebaker, F.M.

2002-01-01

Accurate characterization of individual waste components is critical to ensure design and operation of effective treatment processes and compliance with waste acceptance criteria. Current elemental analysis of organic matrices consists of conversion of the organic sample to aqueous by digesting the sample, which is inadequate in many cases. Direct analysis of the organic would increase sensitivity and decrease contamination and analysis time. For this project, we evaluated an Aridus membrane-desolvation sample introduction system for the direct analysis of organic solvents by Inductively Coupled Plasma - Mass Spectrometry (ICP-MS). The desolvator-ICP-MS successfully analyzed solvent from the caustic-side solvent extraction (CSSX) process and tri-butyl phosphate (TBP) organic tank waste from F-canyon for a variety of elements. Detection limits for most elements were determined in the part per trillion (ppt) range. This technology should increase accuracy in support of SRTC activities involving CSSX and other site processes involving organic compounds

SOLVENT HOLD TANK SAMPLE RESULTS FOR MCU-13-189, MCU-13-190, AND MCU-13-191: QUARTERLY SAMPLE FROM SEPTEMBER 2013

Energy Technology Data Exchange (ETDEWEB)

Fondeur, F.; Taylor-Pashow, K.

2013-10-31

Savannah River National Laboratory (SRNL) analyzed solvent samples from Modular Caustic-Side Solvent Extraction Unit (MCU) in support of continuing operations. A quarterly analysis of the solvent is required to maintain solvent composition within specifications. Analytical results of the analyses of Solvent Hold Tank (SHT) samples MCU-13-189, MCU-13-190, and MCU-13-191 received on September 4, 2013 are reported. The results show that the solvent (remaining heel in the SHT tank) at MCU contains excess Isopar L and a deficit concentration of modifier and trioctylamine when compared to the standard MCU solvent. As with the previous solvent sample results, these analyses indicate that the solvent does not require Isopar L trimming at this time. Since MCU is switching to NGS, there is no need to add TOA nor modifier. SRNL also analyzed the SHT sample for {{sup 137}Cs content and determined the measured value is within tolerance and the value has returned to levels observed in 2011.

Caustic saving potentile in textile processing mills

International Nuclear Information System (INIS)

Latif, M.; Rehman, A.; Ghafar, A.; Hafeez, N.M.

2010-01-01

The textile processing industry of pakistan has great potential of improvement in resource consumption in various production processes. One major concern is the heavy usage of caustic soda (sodium hydroxide) especially during the mercerization process which incurs a significant cost to a textile processing mill. To reduce the unit fabric production cost and stay competitive, the industry need to minimize the caustic wastage and explore the caustic saving potential. This paper describe the detailed caustic consumption practices and saving potentials in woven textile sector based on the data base of 100 industries. Region wise caustic saving potential is also investigated . Three caustic conservation option including process improvement, reuse and recycling, and caustic recovery plants are discussed. Detailed technical and and financial requirements. saving potentials and paybacks of these options are provided. (author)

Space-time caustics

Directory of Open Access Journals (Sweden)

Arthur D. Gorman

1986-01-01

Full Text Available The Lagrange manifold (WKB formalism enables the determination of the asymptotic series solution of linear differential equations modelling wave propagation in spatially inhomogeneous media at caustic (turning points. Here the formalism is adapted to determine a class of asymptotic solutions at caustic points for those equations modelling wave propagation in media with both spatial and temporal inhomogeneities. The analogous Schrodinger equation is also considered.

Caustic Skeleton & Cosmic Web

Science.gov (United States)

Feldbrugge, Job; van de Weygaert, Rien; Hidding, Johan; Feldbrugge, Joost

2018-05-01

We present a general formalism for identifying the caustic structure of a dynamically evolving mass distribution, in an arbitrary dimensional space. The identification of caustics in fluids with Hamiltonian dynamics, viewed in Lagrangian space, corresponds to the classification of singularities in Lagrangian catastrophe theory. On the basis of this formalism we develop a theoretical framework for the dynamics of the formation of the cosmic web, and specifically those aspects that characterize its unique nature: its complex topological connectivity and multiscale spinal structure of sheetlike membranes, elongated filaments and compact cluster nodes. Given the collisionless nature of the gravitationally dominant dark matter component in the universe, the presented formalism entails an accurate description of the spatial organization of matter resulting from the gravitationally driven formation of cosmic structure. The present work represents a significant extension of the work by Arnol'd et al. [1], who classified the caustics that develop in one- and two-dimensional systems that evolve according to the Zel'dovich approximation. His seminal work established the defining role of emerging singularities in the formation of nonlinear structures in the universe. At the transition from the linear to nonlinear structure evolution, the first complex features emerge at locations where different fluid elements cross to establish multistream regions. Involving a complex folding of the 6-D sheetlike phase-space distribution, it manifests itself in the appearance of infinite density caustic features. The classification and characterization of these mass element foldings can be encapsulated in caustic conditions on the eigenvalue and eigenvector fields of the deformation tensor field. In this study we introduce an alternative and transparent proof for Lagrangian catastrophe theory. This facilitates the derivation of the caustic conditions for general Lagrangian fluids, with

Caustic Ingestions

Directory of Open Access Journals (Sweden)

M Rafeey

2014-04-01

Full Text Available Prevention has a main role in reducing the occurrence of corrosive ingestion especially in children, yet this goal is far from being reached in developing countries, where such injuries are largely unreported and their true prevalence simply cannot be extrapolated from random articles or personal experience. Because of the accidental nature of the ingestions, the case fatality rate for pediatric patients is significantly less than that of adolescents and adults.  Currently, esophagoscopy is recommended for all patients with a history of caustic substance ingestion because clinical criteria have not proved to be reliable predictors of esophageal injury. The presence or absence of three serious signs and symptoms-vomiting, drooling, and stridor—as well as the presence and location of oropharyngeal burns could be  compared with the findings on subsequent esophagoscopy. Medical or endoscopic prevention of stricture is debatable, yet esophageal stents, absorbable or not, show promising data. The purpose of this lecture is to outline the current epidemiology, mechanism of injury, clinical manifestations, management and long-term complications of caustic ingestions in pediatric patients.   Key Words: Caustic, Children, Ingestions.

Tunable caustic phenomena in electron wavefields

Energy Technology Data Exchange (ETDEWEB)

Tavabi, Amir Hossein, E-mail: a.tavabi@fz-juelich.de [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C) and Peter Grünberg Institute (PGI), Forschungszentrum Jülich, D-52425 Jülich (Germany); Migunov, Vadim; Dwyer, Christian; Dunin-Borkowski, Rafal E. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C) and Peter Grünberg Institute (PGI), Forschungszentrum Jülich, D-52425 Jülich (Germany); Pozzi, Giulio [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C) and Peter Grünberg Institute (PGI), Forschungszentrum Jülich, D-52425 Jülich (Germany); Department of Physics and Astronomy, University of Bologna, Viale B. Pichat 6/2, 40127 Bologna (Italy)

2015-10-15

Novel caustic phenomena, which contain fold, butterfly and elliptic umbilic catastrophes, are observed in defocused images of two approximately collinear oppositely biased metallic tips in a transmission electron microscope. The observed patterns depend sensitively on defocus, on the applied voltage between the tips and on their separation and lateral offset. Their main features are interpreted on the basis of a projected electrostatic potential model for the electron-optical phase shift. - Highlights: • Electron-optical caustics are observed in defocused images of biased metallic tips. • The caustics depend on defocus, on the bias between the tips and on their separation. • The setup offers the flexibility to study a wide variety of caustic phenomena.

Mitigation of caustic stress corrosion cracking of steam generator tube materials by blowdown -a case study

International Nuclear Information System (INIS)

Dutta, Anu; Patwegar, I.A.; Chaki, S.K.; Venkat Raj, V.

2000-01-01

The vertical U-tube steam generators are among the most important equipment in nuclear power plants as they form the vital link between the reactor and the turbogenerator. Over ∼ 35 years of operating experience of water cooled reactor has demonstrated that steam generator tubes are susceptible to various forms of degradation. This degradation leads to failure and outages of the power plant. A majority of these failures have been attributed to concentrated alkali attacks in the low flow areas such as crevices in the tube to tube sheet joints, baffle plate location and the areas of sludge deposits. Free hydroxides can be produced by improper maintenance of phosphate chemical control in the secondary side of the steam generators and also by the thermal decomposition of impurities present in the condenser cooling water which may leak into the feed water through the condenser tubes. The free hydroxides concentrate in the low flow areas. This buildup of free hydroxide in combination with residual stress leads to caustic stress corrosion cracking. In order to mitigate caustic stress corrosion cracking of Inconel 600 tubes, the trend is to avoid phosphate dosing. Instead All Volatile Treatment (AVT) for secondary water is used backed by full flow condensate polishing. Sodium hydroxide concentration is now being considered as the basis for steam generator blowdown. A methodology has been established for determining the blowdown requirement in order to mitigate caustic stress corrosion cracking in the secondary side of the vertical U-tube natural circulation steam generator. A case study has been carried out for zero solid treatment (AVT coupled with full flow condensate polishing plant) water chemistry. Only continuous blowdown schemes have been studied based on maximum caustic concentration permissible in the secondary side of the steam generator. The methodology established can also be used for deciding concentration of any other impurities

Single Stage Contactor Testing Of The Next Generation Solvent Blend

Energy Technology Data Exchange (ETDEWEB)

Herman, D. T.; Peters, T. B.; Duignan, M. R.; Williams, M. R.; Poirier, M. R.; Brass, E. A.; Garrison, A. G.; Ketusky, E. T.

2014-01-06

The Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) facility at the Savannah River Site (SRS) is actively pursuing the transition from the current BOBCalixC6 based solvent to the Next Generation Solvent (NGS)-MCU solvent to increase the cesium decontamination factor. To support this integration of NGS into the MCU facility the Savannah River National Laboratory (SRNL) performed testing of a blend of the NGS (MaxCalix based solvent) with the current solvent (BOBCalixC6 based solvent) for the removal of cesium (Cs) from the liquid salt waste stream. This testing utilized a blend of BOBCalixC6 based solvent and the NGS with the new extractant, MaxCalix, as well as a new suppressor, tris(3,7dimethyloctyl) guanidine. Single stage tests were conducted using the full size V-05 and V-10 liquid-to-liquid centrifugal contactors installed at SRNL. These tests were designed to determine the mass transfer and hydraulic characteristics with the NGS solvent blended with the projected heel of the BOBCalixC6 based solvent that will exist in MCU at time of transition. The test program evaluated the amount of organic carryover and the droplet size of the organic carryover phases using several analytical methods. The results indicate that hydraulically, the NGS solvent performed hydraulically similar to the current solvent which was expected. For the organic carryover 93% of the solvent is predicted to be recovered from the stripping operation and 96% from the extraction operation. As for the mass transfer, the NGS solvent significantly improved the cesium DF by at least an order of magnitude when extrapolating the One-stage results to actual Seven-stage extraction operation with a stage efficiency of 95%.

Selective solvent extraction of oils

Energy Technology Data Exchange (ETDEWEB)

1938-04-09

In the selective solvent extraction of naphthenic base oils, the solvent used consists of the extract obtained by treating a paraffinic base oil with a selective solvent. The extract, or partially spent solvent is less selective than the solvent itself. Selective solvents specified for the extraction of the paraffinic base oil are phenol, sulphur dioxide, cresylic acid, nitrobenzene, B:B/sup 1/-dichlorethyl ether, furfural, nitroaniline and benzaldehyde. Oils treated are Coastal lubricating oils, or naphthenic oils from the cracking, or destructive hydrogenation of coal, tar, lignite, peat, shale, bitumen, or petroleum. The extraction may be effected by a batch or counter-current method, and in the presence of (1) liquefied propane, or butane, or naphtha, or (2) agents which modify the solvent power such as, water, ammonia, acetonitrile, glycerine, glycol, caustic soda or potash. Treatment (2) may form a post-treatment effected on the extract phase. In counter-current treatment in a tower some pure selective solvent may be introduced near the raffinate outlet to wash out any extract therefrom.

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

Energy Technology Data Exchange (ETDEWEB)

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.

Cesium Concentration in MCU Solvent

International Nuclear Information System (INIS)

Walker, D

2006-01-01

During Modular Caustic-Side Solvent Extraction (CSSX) Unit (MCU) operations, Cs-137 concentrations in product streams will vary depending on the location in the process and on the recent process conditions. Calculations of cesium concentrations under a variety of operating conditions reveal the following: (1) Under nominal operations with salt solution feed containing 1.1 Ci Cs-137 per gallon, the maximum Cs-137 concentration in the process will occur in the strip effluent (SE) and equal 15-16.5 Ci/gal. (2) Under these conditions, the majority of the solvent will contain 0.005 to 0.01 Ci/gal, with a limited portion of the solvent in the contactor stages containing ∼4 Ci/gal. (3) When operating conditions yield product near 0.1 Ci Cs-137/gal in the decontaminated salt solution (DSS), the SE cesium concentration will be the same or lower than in nominal operations, but majority of the stripped solvent will increase to ∼2-3 Ci/gal. (4) Deviations in strip and waste stream flow rates cause the largest variations in cesium content: (a) If strip flow rates deviate by -30% of nominal, the SE will contain ∼23 Ci/gal, although the cesium content of the solvent will increase to only 0.03 Ci/gal; (b) If strip flow rate deviates by -77% (i.e., 23% of nominal), the SE will contain 54 Ci/gal and solvent will contain 1.65 Ci/gal. At this point, the product DSS will just reach the limit of 0.1 Ci/gal, causing the DSS gamma monitors to alarm; and (c) Moderate (+10 to +30%) deviations in waste flow rate cause approximately proportional increases in the SE and solvent cesium concentrations. Recovery from a process failure due to poor cesium stripping can achieve any low cesium concentration required. Passing the solvent back through the contactors while recycling DSS product will produce a ∼70% reduction during one pass through the contactors (assuming the stripping D value is no worse than 0.36). If the solvent is returned to the solvent hold tank (containing additional

Ingestion of caustic substances and its complications

Directory of Open Access Journals (Sweden)

Rui Celso Martins Mamede

2001-01-01

Full Text Available CONTEXT: Caustic substances cause tissue destruction through liquefaction or coagulation reactions and the intensity of destruction depends on the type, concentration, time of contact and amount of the substance ingested. OBJECTIVES: To analyze the complications in patients who ingested caustic substances and correlate them with the amount of caustic soda ingested. DESIGN: Retrospective study. SETTING: University hospital, a referral center. PARTICIPANTS: A total of 239 patients who ingested caustic soda. MAIN MEASUREMENTS: The amount of granulated caustic substance ingested was measured as tablespoonfuls and the following complications were analyzed: esophagitis, esophageal stenosis and progression to cancer, fistulas, perforations, stomach lesions, brain abscesses, and death. Stenosis was classified as mild, moderate or severe according to the radiological findings. RESULTS: We observed an 89.3% incidence of esophagitis; 72.6% of the cases involved progression to stenosis and 1% died during the acute phase. Stenosis was mild in 17.6% of cases, moderate in 59.3% and severe in 23%. The incidence of stenosis was 80.8% in women and 62.5% in men. The incidence of stenosis was 46.9% in the group that ingested "fragments" and 93.6% in the group that ingested one or more tablespoonfuls of caustic substances. Among subjects who ingested one or more tablespoonfuls, 32.2% developed lesions of the stomach-duodenum, whereas the ingestion of "fragments" was not sufficient to induce these lesions. There was no correlation between the intensity of lesions of the esophagus and of the stomach. Progression to cancer of the esophagus occurred in 1.8% of cases, death during the chronic phase in 1.4%, perforations in 4.6%, fistulas in 0.9%, and brain abscesses in 1.4%. CONCLUSIONS: The complications were related to the amount of caustic soda ingested. Small amounts caused esophagitis or stenosis and large amounts increased the risk of fistulas, perforations and

Caustic cracking of 2 1/4 CrMo steel

International Nuclear Information System (INIS)

Cowen, H.C.; Thorley, A.W.

1983-12-01

Stress corrosion cracking tests performed on the 21/4 Cr Mo ferritic steel are described. The principal environments studied were strong, aqueous caustic soda, molten anhydrous caustic soda, and caustic soda with an addition of sodium. Emphasis has been placed on material in the quenched-hardened condition. (author)

Generation of Caustics and Rogue Waves from Nonlinear Instability.

Science.gov (United States)

Safari, Akbar; Fickler, Robert; Padgett, Miles J; Boyd, Robert W

2017-11-17

Caustics are phenomena in which nature concentrates the energy of waves and may exhibit rogue-type behavior. Although they are known mostly in optics, caustics are intrinsic to all wave phenomena. As we demonstrate in this Letter, the formation of caustics and consequently rogue events in linear systems requires strong phase fluctuations. We show that nonlinear phase shifts can generate sharp caustics from even small fluctuations. Moreover, in that the wave amplitude increases dramatically in caustics, nonlinearity is usually inevitable. We perform an experiment in an optical system with Kerr nonlinearity, simulate the results based on the nonlinear Schrödinger equation, and achieve perfect agreement. As the same theoretical framework is used to describe other wave systems such as large-scale water waves, our results may also aid the understanding of ocean phenomena.

Electrochemical generation of fentons reagent to treat spent caustic wastewater

International Nuclear Information System (INIS)

Hansen, H. K.; Nunez, P.; Rodriguez, N.; Guzman, J.

2009-01-01

An important wastewater stream from oil refineries is the spent caustic. Caustic solutions are used as scrubbing agent during the desulphurization process to eliminate sulphur an mercaptans from oil and gasses. Spent caustic is classified as DOO3 (reactive sulphide) hazardous waste under the US Resource Conservation and Recovery Act (RCRA). (Author)

Spectral Caustics in Attosecond Science

Directory of Open Access Journals (Sweden)

Dudovich N.

2013-03-01

Full Text Available A unique type of singularity common in wave phenomena, known as caustics, links processes observed in many different branches of physics [1]. We investigate the role of caustics in attosecond science and in particular the physical process behind high harmonic generation. By exploiting singularities of the three-step model that describes HHG, we can manipulate and enhance specific features in the emitted harmonic spectrum. This new level of control holds promises in both scientific and technological aspects of attosecond science, and provides a deeper insight into the basic mechanism underlying the high harmonic generation process.

Test report - caustic addition system operability test procedure

International Nuclear Information System (INIS)

Parazin, R.E.

1995-01-01

This Operability Test Report documents the test results of test procedure WHC-SD-WM-OTP-167 ''Caustic Addition System Operability Test Procedure''. The Objective of the test was to verify the operability of the 241-AN-107 Caustic Addition System. The objective of the test was met

Catastrophe Theory and Caustics

DEFF Research Database (Denmark)

Gravesen, Jens

1983-01-01

It is shown by elementary methods that in codimension two and under the assumption that light rays are straight lines, a caustic is the catastrophe set for a time function. The general case is also discussed....

Sample Results From The Extraction, Scrub, And Strip Test For The Blended NGS Solvent

Energy Technology Data Exchange (ETDEWEB)

Washington, A. L. II [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Peters, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2014-03-03

This report summarizes the results of the extraction, scrub, and strip testing for the September 2013 sampling of the Next Generation Solvent (NGS) Blended solvent from the Modular Caustic Side-Solvent Extraction Unit (MCU) Solvent Hold Tank. MCU is in the process of transitioning from the BOBCalixC6 solvent to the NGS Blend solvent. As part of that transition, MCU has intentionally created a blended solvent to be processed using the Salt Batch program. This sample represents the first sample received from that blended solvent. There were two ESS tests performed where NGS blended solvent performance was assessed using either the Tank 21 material utilized in the Salt Batch 7 analyses or a simulant waste material used in the V-5/V-10 contactor testing. This report tabulates the temperature corrected cesium distribution, or D_Cs values, step recovery percentage, and actual temperatures recorded during the experiment. This report also identifies the sample receipt date, preparation method, and analysis performed in the accumulation of the listed values. The calculated extraction D_Cs values using the Tank 21H material and simulant are 59.4 and 53.8, respectively. The DCs values for two scrub and three strip processes for the Tank 21 material are 4.58, 2.91, 0.00184, 0.0252, and 0.00575, respectively. The D-values for two scrub and three strip processes for the simulant are 3.47, 2.18, 0.00468, 0.00057, and 0.00572, respectively. These values are similar to previous measurements of Salt Batch 7 feed with lab-prepared blended solvent. These numbers are considered compatible to allow simulant testing to be completed in place of actual waste due to the limited availability of feed material.

Sample Results From The Extraction, Scrub, And Strip Test For The Blended NGS Solvent

International Nuclear Information System (INIS)

Washington, A. L. II; Peters, T. B.

2014-01-01

This report summarizes the results of the extraction, scrub, and strip testing for the September 2013 sampling of the Next Generation Solvent (NGS) Blended solvent from the Modular Caustic Side-Solvent Extraction Unit (MCU) Solvent Hold Tank. MCU is in the process of transitioning from the BOBCalixC6 solvent to the NGS Blend solvent. As part of that transition, MCU has intentionally created a blended solvent to be processed using the Salt Batch program. This sample represents the first sample received from that blended solvent. There were two ESS tests performed where NGS blended solvent performance was assessed using either the Tank 21 material utilized in the Salt Batch 7 analyses or a simulant waste material used in the V-5/V-10 contactor testing. This report tabulates the temperature corrected cesium distribution, or DCs values, step recovery percentage, and actual temperatures recorded during the experiment. This report also identifies the sample receipt date, preparation method, and analysis performed in the accumulation of the listed values. The calculated extraction DCs values using the Tank 21H material and simulant are 59.4 and 53.8, respectively. The DCs values for two scrub and three strip processes for the Tank 21 material are 4.58, 2.91, 0.00184, 0.0252, and 0.00575, respectively. The D-values for two scrub and three strip processes for the simulant are 3.47, 2.18, 0.00468, 0.00057, and 0.00572, respectively. These values are similar to previous measurements of Salt Batch 7 feed with lab-prepared blended solvent. These numbers are considered compatible to allow simulant testing to be completed in place of actual waste due to the limited availability of feed material

1/6TH SCALE STRIP EFFLUENT FEED TANK-MIXING RESULTS USING MCU SOLVENT

Energy Technology Data Exchange (ETDEWEB)

Hansen, E

2006-02-01

The purpose of this task was to determine if mixing was an issue for the entrainment and dispersion of the Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) solvent in the Defense Waste Processing Facility (DWPF) Strip Effluent Feed Tank (SEFT). The MCU strip effluent stream containing the Cs removed during salt processing will be transferred to the DWPF for immobilization in HLW glass. In lab-scale DWPF chemical process cell testing, mixing of the solvent in the dilute nitric acid solution proved problematic, and the Savannah River National Laboratory (SRNL) was requested to perform scaled SEFT mixing tests to evaluate whether the problem was symptomatic of the lab-scale set-up or of the solvent. The solvent levels tested were 228 and 235 ppm, which represented levels near the estimated DWPF solvent limit of 239 ppm in 0.001M HNO{sub 3} solution. The 239 ppm limit was calculated by Norato in X-CLC-S-00141. The general approach for the mixing investigation was to: (1) Investigate the use of fluorescent dyes to aid in observing the mixing behavior. Evaluate and compare the physical properties of the fluorescent dyed MCU solvents to the baseline Oak Ridge CSSX solvent. Based on the data, use the dyed MCU solvent that best approximates the physical properties. (2) Use approximately a 1/6th linear scale of the SEFT to replicate the internal configuration for DWPF mixing. (3) Determine agitator speed(s) for scaled testing based on the DWPF SEFT mixing speed. (4) Perform mixing tests using the 1/6th SEFT and determine any mixing issues (entrainment/dispersion, accumulation, adhesion) through visual observations and by pulling samples to assess uniformity. The mixing tests used MCU solvent fabricated at SRNL blended with Risk Reactor DFSB-K43 fluorescent dye. This dyed SRNL MCU solvent had equivalent physical properties important to mixing as compared to the Oak Ridge baseline solvent, blended easily with the MCU solvent, and provided an excellent visual aid.

Characterization of Solids Deposited on the Modular Caustic-Side Solvent Extraction Unit (MCU) Strip Effluent (SE) Coalescer Media Removed in April 2015

Energy Technology Data Exchange (ETDEWEB)

Fondeur, F. F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2016-06-13

entrance discs of the coalescer. A solvent trim (a cocktail of solvent components with a high concentration of modifier) was added to the solvent on 2/22/2015. It is believed that the trim did not mix completely with the solvent and that it was subsequently spread around the MCU components including the coalescers, where it may have deposited. Chronologically, the modifier, the TiDG’s decomposition products and silicates deposited on the entrance discs first and after the pressure drop increased significantly, parts of the coalescer media detached itself from the central porous steel mandrel and a significant amount of steel debris, mercury, titanium, and additional aluminum and silicates deposited on the coalescer.

21 CFR 2.110 - Definition of ammonia under Federal Caustic Poison Act.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Definition of ammonia under Federal Caustic Poison... SERVICES GENERAL GENERAL ADMINISTRATIVE RULINGS AND DECISIONS Caustic Poisons § 2.110 Definition of ammonia under Federal Caustic Poison Act. For the purpose of determining whether an article containing ammonia...

On the structure of space-time caustics

International Nuclear Information System (INIS)

Rosquist, K.

1983-01-01

Caustics formed by timelike and null geodesics in a space-time M are investigated. Care is taken to distinguish the conjugate points in the tangent space (T-conjugate points) from conjugate points in the manifold (M-conjugate points). It is shown that most nonspacelike conjugate points are regular, i.e. with all neighbouring conjugate points having the same degree of degeneracy. The regular timelike T-conjugate locus is shown to be a smooth 3-dimensional submanifold of the tangent space. Analogously, the regular null T-conjugate locus is shown to be a smooth 2-dimensional submanifold of the light cone in the tangent space. The smoothness properties of the null caustic are used to show that if an observer sees focusing in all directions, then there will necessarily be a cusp in the caustic. If, in addition, all the null conjugate points have maximal degree of degeneracy (as in the closed Friedmann-Robertson-Walker universes), then the space-time is closed. (orig.)

Semiclassical expansions on and near caustics

International Nuclear Information System (INIS)

Meetz, K.

1984-09-01

We show that the standard WKB expansion can be generalized so that it reproduces the behavior of the wave function on and near a caustic in two-dimensional space time. The expansion is related to the unfolding polynomials of the elementary catastrophes occurring in two dimensions: the fold and the cusp catastrophe. The method determines control parameters and transport coefficients in a self-consistent way from differential equations and does not refer to the asymptotic expansion of Feynman path integrals. The lowest order equations are solved explicitly in terms of the multivalued classical action. The result is a generalized semiclassical approximation on and beyond a caustic. (orig.)

Separation processes for the pretreatment of high-level nuclear wastes at the Savannah River site - 59291

International Nuclear Information System (INIS)

Hobbs, David; Peters, Thomas; Taylor-Pashow, Kathryn; Fondeur, Fernando; Nash, Charles; Fink, Samuel; Herman, David; Marra, Jim

2012-01-01

Document available in abstract form only. Full text of publication follows: Separation methods for the pretreatment of the high-level nuclear wastes (HLW) at the Savannah River Site (SRS) include the Caustic Side Solvent Extraction (CSSX) process for cesium and adsorption/ion exchange for the removal of cesium, strontium and alpha-emitting actinides. The CSSX process uses a calixarene extractant in combination with phase modifiers in a hydrocarbon diluent. Monosodium titanate (MST), a hydrous metal oxide, is the baseline material for the removal of strontium and alpha-emitting radionuclides (principally Pu-238, Pu-239, Pu-240 and Np-237). Two pretreatment facilities, the Modular Caustic Side Solvent Extraction Unit (MCU) and the Actinide Removal Process (ARP) facility began radioactive operations at SRS in 2008. Together these facilities can treat approximately 4 million liters of waste per year. The same separation processes are also planned for the much larger Salt Waste Processing Facility (SWPF). The SWPF, which has a design throughput of about 27 million liters per year, is under construction and scheduled to begin radioactive operations in 2014. Current R and D activities for the CSSX process are focused on implementing a new solvent system and stripping flowsheet that offers enhanced extraction and stripping of cesium. This next generation solvent system features a different calixarene extractant, uses caustic instead of nitric acid

Tracking nanoparticles in an optical microscope using caustics

International Nuclear Information System (INIS)

Patterson, Eann A; Whelan, Maurice P

2008-01-01

An elegant method is proposed and demonstrated for tracking the location and movement of nanoparticles in an optical microscope using the optical phenomenon of caustics. A simple and reversible adjustment to the microscope generates caustics several orders of magnitude larger than the particles. The method offers a simple and relatively inexpensive method for visualizing such phenomena as the formation of self-assembled monolayers and the interaction of nanoparticles with chemically functionalized surfaces

Tracking nanoparticles in an optical microscope using caustics

Energy Technology Data Exchange (ETDEWEB)

Patterson, Eann A [Department of Mechanical Engineering, Michigan State University, East Lansing, MI 48824 (United States); Whelan, Maurice P [Nanotechnology and Molecular Imaging Unit, Institute for Health and Consumer Protection, European Commission DG Joint Research Center, 21021 Ispra (Vatican City State, Holy See,) (Italy)

2008-03-12

An elegant method is proposed and demonstrated for tracking the location and movement of nanoparticles in an optical microscope using the optical phenomenon of caustics. A simple and reversible adjustment to the microscope generates caustics several orders of magnitude larger than the particles. The method offers a simple and relatively inexpensive method for visualizing such phenomena as the formation of self-assembled monolayers and the interaction of nanoparticles with chemically functionalized surfaces.

Solvent Extraction Batch Distribution Coefficients with Savannah River Site Dissolved Salt Cake

International Nuclear Information System (INIS)

Walker, D.D.

2002-01-01

Researchers characterized high-level waste derived from dissolved salt cake from the Savannah River Site (SRS) tank farm and measured the cesium distribution coefficients (DCs) for extraction, scrub, and stripping steps of the caustic-side solvent extraction (CSSX) flowsheet. The measurements used two SRS high-level waste samples derived entirely or in part from salt cake. The chemical compositions of both samples are reported. Dissolved salt cake waste contained less Cs-137 and more dianions than is typical of supernate samples. Extraction and scrub DCs values for both samples exceeded process requirements and agreed well with model predictions. Strip DCs values for the Tank 46F sample also met process requirements. However, strip DCs values could not be calculated for the Tank 38H sample due to the poor material balance for Cs-137. Potential explanations for the poor material balance are discussed and additional work to determine the cause is described

Stress corrosion cracking of duplex stainless steels in caustic solutions

Science.gov (United States)

Bhattacharya, Ananya

Duplex stainless steels (DSS) with roughly equal amount of austenite and ferrite phases are being used in industries such as petrochemical, nuclear, pulp and paper mills, de-salination plants, marine environments, and others. However, many DSS grades have been reported to undergo corrosion and stress corrosion cracking in some aggressive environments such as chlorides and sulfide-containing caustic solutions. Although stress corrosion cracking of duplex stainless steels in chloride solution has been investigated and well documented in the literature but the SCC mechanisms for DSS in caustic solutions were not known. Microstructural changes during fabrication processes affect the overall SCC susceptibility of these steels in caustic solutions. Other environmental factors, like pH of the solution, temperature, and resulting electrochemical potential also influence the SCC susceptibility of duplex stainless steels. In this study, the role of material and environmental parameters on corrosion and stress corrosion cracking of duplex stainless steels in caustic solutions were investigated. Changes in the DSS microstructure by different annealing and aging treatments were characterized in terms of changes in the ratio of austenite and ferrite phases, phase morphology and intermetallic precipitation using optical micrography, SEM, EDS, XRD, nano-indentation and microhardness methods. These samples were then tested for general and localized corrosion susceptibility and SCC to understand the underlying mechanisms of crack initiation and propagation in DSS in the above-mentioned environments. Results showed that the austenite phase in the DSS is more susceptible to crack initiation and propagation in caustic solutions, which is different from that in the low pH chloride environment where the ferrite phase is the more susceptible phase. This study also showed that microstructural changes in duplex stainless steels due to different heat treatments could affect their SCC

Test report - 241-AN-274 Caustic Pump Control Building

International Nuclear Information System (INIS)

Paintner, G.P.

1995-05-01

This Acceptance Test Report documents the test results of test procedure WHC-SD-WM-ATP-135 'Acceptance Test Procedure for the 241-AN- 274 Caustic Pump Control Building.' The objective of the test was to verify that the 241-AN-274 Caustic Pump Control Building functions properly based on design specifications per applicable H-2-85573 drawings and associated ECN's. The objective of the test was met

Solvent hold tank sample results for MCU-17-150-152 (July 2017) and MCU-17-153-155 (August 2017): Quarterly report

Energy Technology Data Exchange (ETDEWEB)

Fondeur, F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Jones, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-12-20

A trend summary that includes the last two Solvent Hold Tank (SHT) monthly samples is shown; MCU- 17-150-152 (July SHT) and MCU-17-153-155 (August SHT). Since the last SHT sample sent for analysis was the August sample the chemical state of the solvent is best approximated by the chemical analysis of the August SHT sample (MCU-17-153-155). This report mainly focused on the chemical analysis of the August SHT sample. The analysis data from the July SHT sample are presented in the “trend” plots of this report. Analysis of the August SHT sample (MCU-17-153-155) indicated that the modifier (CS-7SB) was 2% below but the extractant (MaxCalix) concentration was at its nominal recommended level (169,000 mg/L and 46,400 mg/L respectively). The suppressor (TiDG) level has decreased since the last measurement taken while the Modular Caustic-Side Solvent Extraction unit (MCU) was operating in January 2017, but has remained steady in the range of 666 (observed in April) to 715 mg/L (observed in the August 2017 sample) since February 2017, well above the minimum recommended level (479 mg/L), but below the nominal level. The “flat” trends observed in the TiDG, MaxCalix, modifier, and Gamma measurement are consistent with the solvent being idle since January 10, 2017. A strong correlation between density and modifier concentration in the solvent continues to be observed in the SHT samples. This analysis confirms the Isopar™L addition to the solvent in January 2017. This analysis also indicates the solvent did not require further additions. Based on the current monthly sample, the levels of TiDG, Isopar™L, MaxCalix, and modifier are sufficient for continuing operation but are expected to decrease with time if the Modular Caustic-Side Solvent Extraction Unit (MCU) returns to processing radioactive liquid waste. Otherwise, the levels of these components will remain steady. A future Isopar™L trimming addition to the solvent is recommended when MCU resumes processing

Dark matter axions and caustic rings

International Nuclear Information System (INIS)

Sikivie, P.

1997-01-01

This report contains discussions on the following topics: the strong CP problem; dark matter axions; the cavity detector of galactic halo axions; and caustic rings in the density distribution of cold dark matter halos

Structured caustic vector vortex optical field: manipulating optical angular momentum flux and polarization rotation.

Science.gov (United States)

Chen, Rui-Pin; Chen, Zhaozhong; Chew, Khian-Hooi; Li, Pei-Gang; Yu, Zhongliang; Ding, Jianping; He, Sailing

2015-05-29

A caustic vector vortex optical field is experimentally generated and demonstrated by a caustic-based approach. The desired caustic with arbitrary acceleration trajectories, as well as the structured states of polarization (SoP) and vortex orders located in different positions in the field cross-section, is generated by imposing the corresponding spatial phase function in a vector vortex optical field. Our study reveals that different spin and orbital angular momentum flux distributions (including opposite directions) in different positions in the cross-section of a caustic vector vortex optical field can be dynamically managed during propagation by intentionally choosing the initial polarization and vortex topological charges, as a result of the modulation of the caustic phase. We find that the SoP in the field cross-section rotates during propagation due to the existence of the vortex. The unique structured feature of the caustic vector vortex optical field opens the possibility of multi-manipulation of optical angular momentum fluxes and SoP, leading to more complex manipulation of the optical field scenarios. Thus this approach further expands the functionality of an optical system.

A middle age addicted man with caustic stomach

Directory of Open Access Journals (Sweden)

Gholamreza Nouri Broujerdi

2014-06-01

Full Text Available Background: The term caustic generally refers to alkaline and the term corrosive generally refers to acidic agents' injury; however, in medical literature caustic is frequently a term applied to both substances. Ingested alkali typically damage the esophagus more than stomach or duodenum, whereas acids usually cause more severe gastric injury. Since esophagus has a slightly alkaline pH, its epithelium is more resistant to acids, so that only 6 to 20% of those who ingest these substances present lesions in this organ. Case : A middle-aged addicted man who drunk hydrochloric acid accidentally had extensive necrosis of the stomach with remarkable sparing of the esophagus on second look exploration. A total gastrectomy with a Roux-en-Y esophago-jejunostomy with feeding jejunostomy was performed. Conclusion : In caustic GI injury, patients who are operated on and found to have no evidence of extensive esophago-gastric necrosis, a biopsy of the posterior gastric wall should be performed to exclude occult injury. If histologically there is a question of viability, a second look operation should be performed within 36 hours.

Caustic addition system operability test procedure

International Nuclear Information System (INIS)

Parazin, R.E.

1994-11-01

This test procedure provides instructions for performing operational testing of the major components of the 241-AN-107 Caustic Addition System by WHC and Kaiser personnel at the Rotating Equipment Shop run-in pit (Bldg. 272E)

Caustic addition system operability test procedure

Energy Technology Data Exchange (ETDEWEB)

Parazin, R.E.

1994-11-01

This test procedure provides instructions for performing operational testing of the major components of the 241-AN-107 Caustic Addition System by WHC and Kaiser personnel at the Rotating Equipment Shop run-in pit (Bldg. 272E).

Caustic ingestion injuries-at military hospital rawalpindi

International Nuclear Information System (INIS)

Ahsan, O.; Razzaq, K.; Abbas, W.; Zarrin, F.

2015-01-01

To study the pattern and endoscopic severity of caustic ingestion injuries presenting at Military Hospital Rawalpindi. Study Design: Descriptive study. Place and Duration of Study: The study was conducted at Medical and Gastroenterology Department Military Hospital Rawalpindi from August 2012 to April 2013. Material and Methods: Patients were selected from those who presented with caustic ingestion history in Medical OPD, ER and in medical wards. After informed consent the patient underwent upper gastrointestinal (GI) Endoscopy. Endoscopic findings were recorded. Results: Out of 50 patients, 21(42%) were males and 29 (58%) were females. Ingestion was accidental in 19 (38%) and was with intent of suicide or self-harm in 31(62%) patients. Mean age was 33.2 years (SD ± 13.2). All the patients were subjected to upper GI endoscopy and findings were recorded. Endoscopic findings were grade 0 in 4 (8%), Grade 1 in 6 (12%), grade 2a in 7 (14%), grade 2b in 10 (20%), grade 3a in 6 (12%) and grade 3b in 17 (34%) patients. Conclusion: Caustic ingestion injuries were seen more in younger females with predominant cause as suicidal intent. On endoscopic examination severe corrosive injuries were more frequent. (author)

Acid/Caustic Basins: Environmental information document

International Nuclear Information System (INIS)

Ward, J.W.; Johnson, W.F.; Marine, I.W.

1986-12-01

There are six Acid/Caustic Basins at SRP, all of which are located in the reactor and separations areas. These basins are unlined earthen depressions with nominal dimensions of 15.2 m in length x 15.2 m in width x 2.1 m in depth. They were used to provide mixing and partial neutralization of dilute sulfuric acid and sodium hydroxide solutions from water treatment facilities before these solutions were discharged to tributaries of local streams. Closure options considered for the Acid/Caustic Basins are waste removal and closure, no waste removal and closure, and no action. The predominant pathways for human exposure to chemical contaminants are through surface, subsurface, and atmospheric transport. Modeling calculations were made to determine the risks to human population via general pathways for the three postulated closure options. A cost estimate for each closure was also made

Ingestion of Caustic Substances in Adults: A Review Article

Directory of Open Access Journals (Sweden)

Andon Chibishev

2013-02-01

Full Text Available Background: Ingestion of caustic agents can cause serious damages of the upper gastrointestinal tract and in some cases this kind of poisoning may have fatal outcomes. Acute caustic intoxications are one of the main problems in the modern clinical toxicology since they mainly affect young people with psychic disorders, suicidal intent, and alcohol addiction. Text: In diagnostic evaluation of this kind of poisoning, different procedures are used. Today’s golden standard for determination of the grade and extent of the lesion is esophagogastroduodenoscopy (EGD performed in the first 12-24 hours following corrosive ingestion. In some patients, some late complications, such as esophageal stenosis and gastric stenosis, which are the most common, as well as carcinoma of the upper gastrointestinal tract, which is rarely seen, can be detected. Acute caustic poisonings are treated with specific kinds of protocols. According to them, first, an attempt is made to neutralize the poison. Combinations of antibiotics, anti-secretory drugs, and collagen synthesis inhibitors are used. As a support therapy, nutritional liquids can be utilized, and in the most unmanageable cases, esophageal dilatation, stent placement and surgery are used. Conclusion: In the future, caustic poisonings will remain a serious socio-medical issue, due to the difficult clinical presentation, expensive diagnostic protocol, extended hospitalization, and possible permanent disability.

Wavefield extrapolation in caustic-free normal ray coordinates

KAUST Repository

Ma, Xuxin

2012-11-04

Normal ray coordinates are conventionally constructed from ray tracing, which inherently requires smooth velocity profiles. To use rays as coordinates, the velocities have to be smoothed further to avoid caustics, which is detrimental to the mapping process. Solving the eikonal equation numerically for a line source at the surface provides a platform to map normal rays in complex unsmoothed velocity models and avoid caustics. We implement reverse-time migration (RTM) and downward continuation in the new ray coordinate system, which allows us to obtain efficient images and avoid some of the dip limitations of downward continuation.

Density Changes in the Optimized CSSX Solvent System

Energy Technology Data Exchange (ETDEWEB)

Lee, D.D.

2002-11-25

Density increases in caustic-side solvent extraction (CSSX) solvent have been observed in separate experimental programs performed by different groups of researchers. Such changes indicate a change in chemical composition. Increased density adversely affects separation of solvent from denser aqueous solutions present in the CSSX process. Identification and control of factors affecting solvent density are essential for design and operation of the centrifugal contactors. The goals of this research were to identify the factors affecting solvent density (composition) and to develop correlations between easily measured solvent properties (density and viscosity) and the chemical composition of the solvent, which will permit real-time determination and adjustment of the solvent composition. In evaporation experiments, virgin solvent was subjected to evaporation under quiescent conditions at 25, 35, and 45 C with continuously flowing dry air passing over the surface of the solvent. Density and viscosity were measured periodically, and chemical analysis was performed on the solvent samples. Chemical interaction tests were completed to determine if any chemical reaction takes place over extended contact time that changes the composition and/or physical properties. Solvent and simulant, solvent and strip solution, and solvent and wash solution were contacted continuously in agitated flasks. They were periodically sampled and the density measured (viscosity was also measured on some samples) and then submitted to the Chemical Sciences Division of Oak Ridge National Laboratory for analysis by nuclear magnetic resonance (NMR) spectrometry and high-performance liquid chromatography (HPLC) using the virgin solvent as the baseline. Chemical interaction tests showed that solvent densities and viscosities did not change appreciably during contact with simulant, strip, or wash solution. No effects on density and viscosity and no chemical changes in the solvent were noted within

Hydrogen peroxide and caustic soda: Dancing with a dragon while bleaching

Science.gov (United States)

Peter W. Hart; Carl Houtman; Kolby Hirth

2013-01-01

When hydrogen peroxide is mixed with caustic soda, an auto-accelerating reaction can lead to generation of significant amounts of heat and oxygen. On the basis of experiments using typical pulp mill process concentration and temperatures, a relatively simple kinetic model has been developed. Evaluation of these model results reveals that hydrogen peroxide-caustic soda...

Epidemiology and prevention of caustic ingestion in children

DEFF Research Database (Denmark)

Christesen, H B

1994-01-01

A total of 102 children less than 16 years of age admitted for caustic ingestion in the period 1976-1991 were registered. The annual incidence rate of hospitalization was 10.8:100,000 for the city of Aarhus, Denmark. Esophageal burns occurred with a frequency of 5.0:100,000 per year. Ninety-four ...... of toddlers is recommended. Information material should stress that caustics should always be inaccessible to children and stored separately, and should never be decanted.......A total of 102 children less than 16 years of age admitted for caustic ingestion in the period 1976-1991 were registered. The annual incidence rate of hospitalization was 10.8:100,000 for the city of Aarhus, Denmark. Esophageal burns occurred with a frequency of 5.0:100,000 per year. Ninety......-four percent of the children were less than 5 years old. For this age group, the incidence rates of admission and esophageal burns were 34.6:100,000 and 15.8:100,000, respectively. All ingestions were accidental. The incidence rates of esophageal burns in children 0-4 years old (p = 0.019) decreased...

Studying the microlenses mass function from statistical analysis of the caustic concentration

Energy Technology Data Exchange (ETDEWEB)

Mediavilla, T; Ariza, O [Departamento de Estadistica e Investigacion Operativa, Universidad de Cadiz, Avda de Ramon Puyol, s/n 11202 Algeciras (Spain); Mediavilla, E [Instituto de Astrofisica de Canarias, Avda Via Lactea s/n, La Laguna (Spain); Munoz, J A, E-mail: teresa.mediavilla@ca.uca.es, E-mail: octavio.ariza@uca.es, E-mail: emg@iac.es [Departamento de Astrofisica y Astronomia, Universidad de Valencia, Burjassot, Valencia (Spain)

2011-09-22

The statistical distribution of caustic crossings by the images of a lensed quasar depends on the properties of the distribution of microlenses in the lens galaxy. We use a procedure based in Inverse Polygon Mapping to easily identify the critical and caustic curves generated by a distribution of stars in the lens galaxy. We analyze the statistical distributions of the number of caustic crossings by a pixel size source for several projected mass densities and different mass distributions. We compare the results of simulations with theoretical binomial distributions. Finally we apply this method to the study of the stellar mass distribution in the lens galaxy of QSO 2237+0305.

16 CFR 1500.129 - Substances named in the Federal Caustic Poison Act.

Science.gov (United States)

2010-01-01

... Poison Act. 1500.129 Section 1500.129 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL... REGULATIONS § 1500.129 Substances named in the Federal Caustic Poison Act. The Commission finds that for those substances covered by the Federal Caustic Poison Act (44 Stat. 1406), the requirements of section 2(p)(1) of...

Caustic leaching of composite AZ-101/AZ-102 Hanford tank sludge

International Nuclear Information System (INIS)

Rapko, B.M.; Wagner, M.J.

1997-07-01

To reduce the quantity (and hence the cost) of glass canisters needed for disposing of high-level radioactive wastes from the Hanford tank farms, pretreatment processes are needed to remove as much nonradioactive material as possible. This report describes the results of a laboratory-scale caustic leaching test performed on a composite derived from a combination of 241-AZ-101 and 241-AZ-102 Hanford Tank sludges. The goals of this FY 1996 test were to evaluate the effectiveness of caustic leaching on removing key components from the sludge and to evaluate the effectiveness of varying the free-hydroxide concentrations by incrementally increasing the free hydroxide concentration of the leach steps up to 3 M free hydroxide. Particle-size analysis of the treated and untreated sludge indicated that the size and range of the sludge particles remained essentially unchanged by the caustic leaching treatment. Both before and after caustic leaching, a particle range of 0.2 microm to 50 microm was observed, with mean particle diameters of 8.5 to 9 microm based on the volume distribution and mean particle diameters of 0.3 to 0.4 microm based on the number distribution

Solvent dielectric effect and side chain mutation on the structural stability of Burkholderia cepacia lipase active site: a quantum mechanical/molecular mechanics study.

Science.gov (United States)

Tahan, A; Monajjemi, M

2011-12-01

Quantum mechanical and molecular dynamics methods were used to analyze the structure and stability of neutral and zwitterionic configurations of the extracted active site sequence from a Burkholderia cepacia lipase, histidyl-seryl-glutamin (His86-Ser87-Gln88) and its mutated form, histidyl-cysteyl-glutamin (His86-Cys87-Gln88) in vacuum and different solvents. The effects of solvent dielectric constant, explicit and implicit water molecules and side chain mutation on the structure and stability of this sequence in both neutral and zwitterionic forms are represented. The quantum mechanics computations represent that the relative stability of zwitterionic and neutral configurations depends on the solvent structure and its dielectric constant. Therefore, in vacuum and the considered non-polar solvents, the neutral form of the interested sequences is more stable than the zwitterionic form, while their zwitterionic form is more stable than the neutral form in the aqueous solution and the investigated polar solvents in most cases. However, on the potential energy surfaces calculated, there is a barrier to proton transfer from the positively charged ammonium group to the negatively charged carboxylat group or from the ammonium group to the adjacent carbonyl oxygen and or from side chain oxygen and sulfur to negatively charged carboxylat group. Molecular dynamics simulations (MD) were also performed by using periodic boundary conditions for the zwitterionic configuration of the hydrated molecules in a box of water molecules. The obtained results demonstrated that the presence of explicit water molecules provides the more compact structures of the studied molecules. These simulations also indicated that side chain mutation and replacement of sulfur with oxygen leads to reduction of molecular flexibility and packing.

Caustic meso-optical confocal microscope for vertical particle tracks. Proposal

International Nuclear Information System (INIS)

Soroko, L.M.

1995-01-01

The principal of the proposed caustic meso-optical microscope for vertical particle tracks in the nuclear photoemulsion is explained. The results of the experiments performed to illustrate the main features of this new meso-optical microscope are given. The proposed caustic meso-optical microscope for vertical particle tracks in the nuclear photoemulsion can be effectively used in the experimental investigation of such rare processes as ν μ - ν τ oscillations and of the Pb-Pb interactions. 2 refs., 7 figs

Safety basis for the 241-AN-107 mixer pump installation and caustic addition

International Nuclear Information System (INIS)

Van Vleet, R.J.

1994-01-01

This safety Basis was prepared to determine whether or not the proposed activities of installing a 76 HP jet mixer pump and the addition of approximately 50,000 gallons of 19 M (50:50 wt %) aqueous caustic are within the safety envelope as described by Tank Farms (chapter six of WHC-SD-WM-ISB-001, Rev. 0). The safety basis covers the components, structures and systems for the caustic addition and mixer pump installation. These include: installation of the mixer pump and monitoring equipment; operation of the mixer pump, process monitoring equipment and caustic addition; the pump stand, caustic addition skid, the electrical skid, the video camera system and the two densitometers. Also covered is the removal and decontamination of the mixer pump and process monitoring system. Authority for this safety basis is WHC-IP-0842 (Waste Tank Administration). Section 15.9, Rev. 2 (Unreviewed Safety Questions) of WHC-IP-0842 requires that an evaluation be performed for all physical modifications

Robustness of discrete flows and caustics in cold dark matter cosmology

International Nuclear Information System (INIS)

Natarajan, Aravind; Sikivie, Pierre

2005-01-01

Although a simple argument implies that the distribution of dark matter in galactic halos is characterized by discrete flows and caustics, their presence is often ignored in discussions of galactic dynamics and of dark matter detection strategies. Discrete flows and caustics can in fact be irrelevant if the number of flows is very large. We estimate the number of dark matter flows as a function of galactocentric distance and consider the various ways in which that number can be increased, in particular, by the presence of structure on small scales (dark matter clumps) and the scattering of the flows by inhomogeneities in the matter distribution. We find that, when all complicating factors are taken into account, discrete flows and caustics in galactic halos remain a robust prediction of cold dark matter cosmology with extensive implications for observation and experiment

Biodegradable Stents for Caustic Esophageal Strictures: Do They Work?

Science.gov (United States)

Kochhar, Rakesh; Samanta, Jayanta; Basha, Jahangeer; Verma, Abhai; Choudhuri, Gourdas; Lakhtakia, Sundeep; Reddy, D Nageshwar

2017-08-01

Biodegradable (BD) stents have been used for the management of various esophageal strictures (ES) but the experience of its use in caustic strictures is limited. The present study, aimed at evaluating efficacy of BD stents for the treatment of refractory caustic-induced ES, was a retrospective multi-center study conducted at three tertiary care centers in India wherein adult patients with refractory caustic induced strictures underwent placement of a BD stent. Patients were followed up for immediate complications and long term outcome. All 13 patients (39.3 ± 15.1 years) underwent successful BD stent placement. Retrosternal chest pain occurred in 2 patients and stent migration in 1 (7.6%) patient. At 3 months, restenosis with recurrence of dysphagia was seen in nine (69.2%) patients, at 6 months, 10 (77%) patients had dysphagia of whom three underwent surgery and the remaining seven patients required dilatations. At 1 year, one patient remained asymptomatic while nine had dysphagia. The requirement for dilatation was once in 3 months in seven patients & once in a month in two patients. At 2 years, the requirement of dilatations was further reduced to once in 4-6 months in all patients. Over a 3 year follow up three (23%) patients had undergone surgery, one was free of symptoms while nine patients continued to be on periodic dilatation although the requirement had reduced to once in 4-6 months. Efficacy of BD stents in patients with caustic-induced ES is limited and the short term radial force applied by the currently available BD stents is inadequate to provide long term relief in such patients.

Biological treatment of sulfidic spent caustics under haloalkaline conditions using soda lake bacteria

NARCIS (Netherlands)

Graaff, de C.M.

2012-01-01

In this thesis, the development of a newbiotechnological process for the treatment of undiluted sulfidic spent caustics (SSC’s) using soda lake bacteria is described. SSC’s are waste solutions that are formed in the oil and gas industry due to the caustic (NaOH) scrubbing of hydrocarbon streams

Monitoring caustic injuries from emergency department databases using automatic keyword recognition software.

Science.gov (United States)

Vignally, P; Fondi, G; Taggi, F; Pitidis, A

2011-03-31

In Italy the European Union Injury Database reports the involvement of chemical products in 0.9% of home and leisure accidents. The Emergency Department registry on domestic accidents in Italy and the Poison Control Centres record that 90% of cases of exposure to toxic substances occur in the home. It is not rare for the effects of chemical agents to be observed in hospitals, with a high potential risk of damage - the rate of this cause of hospital admission is double the domestic injury average. The aim of this study was to monitor the effects of injuries caused by caustic agents in Italy using automatic free-text recognition in Emergency Department medical databases. We created a Stata software program to automatically identify caustic or corrosive injury cases using an agent-specific list of keywords. We focused attention on the procedure's sensitivity and specificity. Ten hospitals in six regions of Italy participated in the study. The program identified 112 cases of injury by caustic or corrosive agents. Checking the cases by quality controls (based on manual reading of ED reports), we assessed 99 cases as true positive, i.e. 88.4% of the patients were automatically recognized by the software as being affected by caustic substances (99% CI: 80.6%- 96.2%), that is to say 0.59% (99% CI: 0.45%-0.76%) of the whole sample of home injuries, a value almost three times as high as that expected (p < 0.0001) from European codified information. False positives were 11.6% of the recognized cases (99% CI: 5.1%- 21.5%). Our automatic procedure for caustic agent identification proved to have excellent product recognition capacity with an acceptable level of excess sensitivity. Contrary to our a priori hypothesis, the automatic recognition system provided a level of identification of agents possessing caustic effects that was significantly much greater than was predictable on the basis of the values from current codifications reported in the European Database.

Caustic Recycling Pilot Unit to Separate Sodium from LLW at Hanford Site - 12279

Energy Technology Data Exchange (ETDEWEB)

Pendleton, Justin; Bhavaraju, Sai; Priday, George; Desai, Aditya; Duffey, Kean; Balagopal, Shekar [Ceramatec Inc., Salt Lake City, UT 84119 (United States)

2012-07-01

As part of the Department of Energy (DOE) sponsored Advanced Remediation Technologies initiative, a scheme was developed to combine Continuous Sludge Leaching (CSL), Near-Tank Cesium Removal (NTCR), and Caustic Recycling Unit (CRU) using Ceramatec technology, into a single system known as the Pilot Near-Tank Treatment System (PNTTS). The Cesium (Cs) decontaminated effluent from the NTCR process will be sent to the caustic recycle process for recovery of the caustic which will be reused in another cycle of caustic leaching in the CSL process. Such an integrated mobile technology demonstration will give DOE the option to insert this process for sodium management at various sites in Hanford, and will minimize the addition of further sodium into the waste tanks. This allows for recycling of the caustic used to remove aluminum during sludge washing as a pretreatment step in the vitrification of radioactive waste which will decrease the Low Level Waste (LLW) volume by as much as 39%. The CRU pilot process was designed to recycle sodium in the form of pure sodium hydroxide. The basis for the design of the 1/4 scale pilot caustic recycling unit was to demonstrate the efficient operation of a larger scale system to recycle caustic from the NTCR effluent stream from the Parsons process. The CRU was designed to process 0.28 liter/minute of NTCR effluent, and generate 10 M concentration of 'usable' sodium hydroxide. The proposed process operates at 40 deg. C to provide additional aluminum solubility and then recover the sodium hydroxide to the point where the aluminum is saturated at 40 deg. C. A system was developed to safely separate and vent the gases generated during operation of the CRU with the production of 10 M sodium hydroxide. Caustic was produced at a rate between 1.9 to 9.3 kg/hr. The CRU was located inside an ISO container to allow for moving of the unit close to tank locations to process the LLW stream. Actual tests were conducted with the NTCR effluent

Analysis of caustic soda of different manufacturers in pakistan for mercerization of cotton textiles

International Nuclear Information System (INIS)

Zahid, B.; Faisal, S.; Siddique, S.H.

2017-01-01

Pakistan has sufficient production capacity of caustic soda to cater the needs of the local industry. Presently, Pakistan has four major plants with production capacity around 435,000 mega ton per year of caustic soda of various grades. Textile industry of Pakistan is the major consumer of produced high grade caustic soda; as the presence of any impurities especially dissolved salts and metals is unfavorable for wet processing of cotton. This study investigates the performance of three different local brands of caustic soda intended for use in textile wet processing of cotton fabric specifically for mercerization process. The brands were selected based on their purity grades. The selected caustic soda samples were chemically analyzed for the presence of impurities. Twenty seven cotton fabric samples (nine samples of each brand) were prepared by mercerization in slack state. The cotton fabric samples were tested for changes in surface morphology, tensile strength (warp and weft), tear strength, air permeability and K/S (Colour Strength). The results were analyzed using one-way ANOVA (Analysis of Variance) to ascertain the statistical equivalence within and between the tested brands. The results showed no significant differences across the tested brands at a 95% confidence level except for air permeability and K/S in blue shade. (author)

Wavefield extrapolation in caustic-free normal ray coordinates

KAUST Repository

Ma, Xuxin; Alkhalifah, Tariq Ali

2012-01-01

Normal ray coordinates are conventionally constructed from ray tracing, which inherently requires smooth velocity profiles. To use rays as coordinates, the velocities have to be smoothed further to avoid caustics, which is detrimental to the mapping

Test Procedure - pumping system for caustic addition project

International Nuclear Information System (INIS)

Leshikar, G.A.

1994-01-01

This test procedure provides the requirements for sub-system testing and integrated operational testing of the submersible mixer pump and caustic addition equipment by WHC and Kaiser personnel at the Rotating Equipment Shop run-in pit (Bldg. 272E)

Prediction of complications following caustic ingestion in adults

DEFF Research Database (Denmark)

Christesen, H B

1995-01-01

The records of 86 adults admitted to hospital following caustic ingestion were reviewed. Eighteen patients (21%) developed complications; of these, six were fatal. Patients without symptoms or signs did not develop complications. Complications occurred only following lye ingestion, or intentional...

Radioactive Demonstration of Caustic Recovery from Low-Level Alkaline Nuclear Waste by an Electrochemical Separation Process

International Nuclear Information System (INIS)

Hobbs, D.T.

1998-04-01

Bench-scale radioactive tests successfully demonstrated an electrochemical process for the recovery of sodium hydroxide (caustic) from Decontaminated Salt Solution produced from the In-Tank Precipitation and Effluent Treatment Processes at the Savannah River Site (SRS). This testing evaluated two membranes: an organic-based membrane, Nafion Type 350, manufactured by E. I. duPont de Nemours ampersand Company, Inc. (DuPont) and an inorganic-based membrane, NAS D, being developed by Ceramatec. Both membranes successfully separated caustic from radioactive SRS waste.Key findings of the testing indicate the following attributes and disadvantages of each membrane. The commercially-available Nafion membrane proved highly conductive. Thus, the electrochemical cell can operate at high current density minimizing the number of cells at the desired volumetric processing rate. Testing indicated cesium transported across the Nafion membrane into the caustic product. Therefore, the caustic product will contain low-levels of radioactive cesium due to the presence of 134,137 Cs in the waste feed. To meet customer requirements, a post treatment stage may prove necessary to remove radioactive cesium resulting in increased overall process costs and decreased cost savings. In contrast to the Nafion membrane, the NAS D membrane demonstrated the production of caustic with much lower levels of gamma radioactivity ( 137 Cs activity was < 51 dpm/g). Therefore, the caustic product could possibly release for onsite/offsite use without further treatment. The NAS D membrane remains in the development stage and does not exist as a commercial product. Operating costs and long-term membrane durability remain unknown.Caustic recovery has been successfully demonstrated in a bench-scale, 2-compartment electrochemical reactor operated for brief periods of time with simulated and radioactive waste solutions and two different types of membranes. The next phase of testing should be directed at (1

Proceedings: 1991 EPRI workshop on secondary-side intergranular corrosion mechanisms

International Nuclear Information System (INIS)

Partridge, M.J.; Zemitis, W.S.

1992-08-01

A workshop on ''Secondary-Side Intergranular Corrosion Mechanisms'' was organized by EPRI as an effort to give those working in this area an opportunity to share their results, ideas, and plans. Topics covered included: (1) caustic induced intergranular attack/stress corrosion cracking (IGA/IGSCC), (2) plant experience, (3) boric acid as an IGA/IGSCC remedial measure, (4) lead induced IGA/IGSCC, and (5) acid induced IGA/IGSCC

New strategies for treatment and reuse of spent sulfidic caustic stream from petroleum industry

Directory of Open Access Journals (Sweden)

Jéssica Frontino Paulino

2012-01-01

Full Text Available This work examines traditional and new routes for removal of H2S and other sulfur compounds from spent sufidic caustic (SSC. SH- (hydrogenosulfide and S2- (sulfide ions were quantitatively oxidized at 25 ºC using H2O2, NaOCl or a spent sulfochromic mixture. SH-/S2- ions were also removed via reaction with freshly prepared iron or manganese hydroxides, or after passing the SSC through strong basic anion exchange resins (OH- form. The treated caustic solution, as well as iron/manganese hydroxides, removed H2S from diesel samples at 25 ºC. SSC treatment via strong basic anion-exchange resins produced the treated caustic solution with the highest free alkalinity.

A uniform geometrical optics and an extended uniform geometrical theory of diffraction for evaluating high frequency EM fields near smooth caustics and composite shadow boundaries

Science.gov (United States)

Constantinides, E. D.; Marhefka, R. J.

1994-01-01

A uniform geometrical optics (UGO) and an extended uniform geometrical theory of diffraction (EUTD) are developed for evaluating high frequency electromagnetic (EM) fields within transition regions associated with a two and three dimensional smooth caustic of reflected rays and a composite shadow boundary formed by the caustic termination or the confluence of the caustic with the reflection shadow boundary (RSB). The UGO is a uniform version of the classic geometrical optics (GO). It retains the simple ray optical expressions of classic GO and employs a new set of uniform reflection coefficients. The UGO also includes a uniform version of the complex GO ray field that exists on the dark side of the smooth caustic. The EUTD is an extension of the classic uniform geometrical theory of diffraction (UTD) and accounts for the non-ray optical behavior of the UGO reflected field near caustics by using a two-variable transition function in the expressions for the edge diffraction coefficients. It also uniformly recovers the classic UTD behavior of the edge diffracted field outside the composite shadow boundary transition region. The approach employed for constructing the UGO/EUTD solution is based on a spatial domain physical optics (PO) radiation integral representation for the fields which is then reduced using uniform asymptotic procedures. The UGO/EUTD analysis is also employed to investigate the far-zone RCS problem of plane wave scattering from two and three dimensional polynomial defined surfaces, and uniform reflection, zero-curvature, and edge diffraction coefficients are derived. Numerical results for the scattering and diffraction from cubic and fourth order polynomial strips are also shown and the UGO/EUTD solution is validated by comparison to an independent moment method (MM) solution. The UGO/EUTD solution is also compared with the classic GO/UTD solution. The failure of the classic techniques near caustics and composite shadow boundaries is clearly

Laser Beam Caustic Measurement with Focal Spot Analyser

DEFF Research Database (Denmark)

Olsen, Flemming Ove; Gong, Hui; Bagger, Claus

2005-01-01

In industrial applications of high power CO2-lasers the caustic characteristics of the laser beam have great effects on the performance of the lasers. A welldefined high intense focused spot is essential for reliable production results. This paper presents a focal spot analyser that is developed...

EFRT M-12 Issue Resolution: Caustic Leach Rate Constants from PEP and Laboratory-Scale Tests

Energy Technology Data Exchange (ETDEWEB)

Mahoney, Lenna A.; Rassat, Scot D.; Eslinger, Paul W.; Aaberg, Rosanne L.; Aker, Pamela M.; Golovich, Elizabeth C.; Hanson, Brady D.; Hausmann, Tom S.; Huckaby, James L.; Kurath, Dean E.; Minette, Michael J.; Sundaram, S. K.; Yokuda, Satoru T.

2009-08-14

Testing Summary Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed and constructed and is to be operated as part of a plan to respond to issue M12, “Undemonstrated Leaching Processes.” The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. The PEP also includes non-prototypic ancillary equipment to support the core processing. Two operating scenarios are currently being evaluated for the ultrafiltration process (UFP) and leaching operations. The first scenario has caustic leaching performed in the UFP-2 ultrafiltration feed vessels (i.e., vessel UFP-VSL-T02A in the PEP and vessels UFP-VSL-00002A and B in the WTP PTF). The second scenario has caustic leaching conducted in the UFP-1 ultrafiltration feed preparation vessels (i.e., vessels UFP-VSL-T01A and B in the PEP; vessels UFP-VSL-00001A and B in the WTP PTF). In both scenarios, 19-M sodium hydroxide solution (NaOH, caustic) is added to the waste slurry in the vessels to leach solid aluminum compounds (e.g., gibbsite, boehmite). Caustic addition is followed by a heating step that uses direct injection of steam to accelerate the leaching process. Following the caustic leach, the vessel contents are cooled using vessel cooling jackets and/or external heat exchangers. The main difference between the two scenarios is that for leaching in UFP-1, the 19-M NaOH is added to un-concentrated waste slurry (3 to 8 wt% solids), while for leaching in UFP-2, the slurry is

EFRT M-12 Issue Resolution: Caustic Leach Rate Constants from PEP and Laboratory-Scale Tests

International Nuclear Information System (INIS)

Mahoney, Lenna A.; Rassat, Scot D.; Eslinger, Paul W.; Aaberg, Rosanne L.; Aker, Pamela M.; Golovich, Elizabeth C.; Hanson, Brady D.; Hausmann, Tom S.; Huckaby, James L.; Kurath, Dean E.; Minette, Michael J.; Sundaram, S. K.; Yokuda, Satoru T.

2009-01-01

Testing Summary Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed and constructed and is to be operated as part of a plan to respond to issue M12, 'Undemonstrated Leaching Processes.' The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. The PEP also includes non-prototypic ancillary equipment to support the core processing. Two operating scenarios are currently being evaluated for the ultrafiltration process (UFP) and leaching operations. The first scenario has caustic leaching performed in the UFP-2 ultrafiltration feed vessels (i.e., vessel UFP-VSL-T02A in the PEP and vessels UFP-VSL-00002A and B in the WTP PTF). The second scenario has caustic leaching conducted in the UFP-1 ultrafiltration feed preparation vessels (i.e., vessels UFP-VSL-T01A and B in the PEP; vessels UFP-VSL-00001A and B in the WTP PTF). In both scenarios, 19-M sodium hydroxide solution (NaOH, caustic) is added to the waste slurry in the vessels to leach solid aluminum compounds (e.g., gibbsite, boehmite). Caustic addition is followed by a heating step that uses direct injection of steam to accelerate the leaching process. Following the caustic leach, the vessel contents are cooled using vessel cooling jackets and/or external heat exchangers. The main difference between the two scenarios is that for leaching in UFP-1, the 19-M NaOH is added to un-concentrated waste slurry (3 to 8 wt% solids), while for leaching in UFP-2, the slurry is concentrated

Wavefronts, light rays and caustic of a circular wave reflected by an arbitrary smooth curve

International Nuclear Information System (INIS)

Marciano-Melchor, Magdalena; Silva-Ortigoza, Ramón; Montiel-Piña, Enrique; Román-Hernández, Edwin; Santiago-Santiago, José Guadalupe; Silva-Ortigoza, Gilberto; Rosado, Alfonso; Suárez-Xique, Román

2011-01-01

The aim of the present work is to obtain expressions for both the wavefront train and the caustic associated with the light rays reflected by an arbitrary smooth curve after being emitted by a point light source located at an arbitrary position in the two-dimensional free space. To this end, we obtain an expression for the k-function associated with the general integral of Stavroudis to the eikonal equation that describes the evolution of the reflected light rays. The caustic is computed by using the definitions of the critical and caustic sets of the two-dimensional map that describes the evolution of an arbitrary wavefront associated with the general integral. The general results are applied to circular and parabolic mirrors. The main motivation to carry out this research is to establish, in future work, the caustic touching theorem in a two-dimensional optical medium and to study the diffraction problem by using the k-function concept. Both problems are important in the computation of the image of an arbitrary object under reflection and refraction

Novel Electrochemical Treatment of Spent Caustic from the Hydrocarbon Industry Using Ti/BDD

Directory of Open Access Journals (Sweden)

Alejandro Medel

2015-01-01

Full Text Available During the crude oil refining process, NaOH solutions are used to remove H2S, H2Saq, and sulfur compounds from different hydrocarbon streams. The residues obtained are called “spent caustics.” These residues can be mixed with those obtained in other processes, adding to its chemical composition naphthenic acids and phenolic compounds, resulting in one of the most dangerous industrial residues. In this study, the use of electrochemical technology (ET, using BDD with Ti as substrate (Ti/BDD, is evaluated in electrolysis of spent caustic mixtures, obtained through individual samples from different refineries. In this way, the Ti/BDD’s capability of carrying out the electrochemical destruction of spent caustics in an acidic medium is evaluated having as key process a chemical pretreatment phase. The potential production of •OHs, as the main reactive oxygen species electrogenerated over Ti/BDD surface, was evaluated in HCl and H2SO4 through fluorescence spectroscopy, demonstrating the reaction medium’s influence on its production. The results show that the hydrocarbon industry spent caustics can be mineralized to CO2 and water, driving the use of ET and of the Ti/BDD to solve a real problem, whose potential and negative impact on the environment and on human health is and has been the environmental agencies’ main focus.

K Basin Sludge Conditioning Process Testing Partitioning of PCBs in Dissolver Solution After Neutralization/Precipitation (Caustic Adjustment)

International Nuclear Information System (INIS)

Schmidt, A.J.; Thornton, B.M.; Hoppe, E.W.; Mong, G.M.; Silvers, K.L.; Slate, S.O.

1999-01-01

The purpose of the work described in this report was to gain a better understanding of how PCB congeners present in a simulated K Basin sludge dissolver solution will partition upon neutralization and precipitation (i.e., caustic adjustment). In a previous study (Mong et al. 1998),the entire series of sludge conditioning steps (acid dissolution, filtration, and caustic adjustment) were examined during integrated testing. In the work described here, the caustic adjustment step was isolated to examine the fate of PCBs in more detail within this processing step. For this testing, solutions of dissolver simulant (containing no solids) with a known initial concentration of PCB congeners were neutralized with caustic to generate a clarified supernatant and a settled sludge phase. PCBs were quantified in each phase (including the PCBs associated with the test vessel rinsates), and material balance information was collected

The Impact Of The MCU Life Extension Solvent On Sludge Batch 8 Projected Operating Windows

International Nuclear Information System (INIS)

Peeler, D. K.; Edwards, T. B.; Stone, M. E.

2013-01-01

As a part of the Actinide Removal Process (ARP)/Modular Caustic Side Solvent Extraction Unit (MCU) Life Extension Project, a next generation solvent (NGS) and a new strip acid will be deployed. The strip acid will be changed from dilute nitric acid to dilute boric acid (0.01 M). Because of these changes, experimental testing or evaluations with the next generation solvent are required to determine the impact of these changes (if any) to Chemical Process Cell (CPC) activities, glass formulation strategies, and melter operations at the Defense Waste Processing Facility (DWPF). The introduction of the dilute (0.01M) boric acid stream into the DWPF flowsheet has a potential impact on glass formulation and frit development efforts since B2O3 is a major oxide in frits developed for DWPF. Prior knowledge of this stream can be accounted for during frit development efforts but that was not the case for Sludge Batch 8 (SB8). Frit 803 has already been recommended and procured for SB8 processing; altering the frit to account for the incoming boron from the strip effluent (SE) is not an option for SB8. Therefore, the operational robustness of Frit 803 to the introduction of SE including its compositional tolerances (i.e., up to 0.0125M boric acid) is of interest and was the focus of this study. The primary question to be addressed in the current study was: What is the impact (if any) on the projected operating windows for the Frit 803 - SB8 flowsheet to additions of B2O3 from the SE in the Sludge Receipt and Adjustment Tank (SRAT)? More specifically, will Frit 803 be robust to the potential compositional changes occurring in the SRAT due to sludge variation, varying additions of ARP and/or the introduction of SE by providing access to waste loadings (WLs) of interest to DWPF? The Measurement Acceptability Region (MAR) results indicate there is very little, if any, impact on the projected operating windows for the Frit 803 - SB8 system regardless of the presence or absence of

Test Results for Caustic Demand Measurements on Tank 241-AX-101 and Tank 241-AX-103 Archive Samples

International Nuclear Information System (INIS)

Doll, Stephanie R.; Bolling, Stacie D.

2016-01-01

Caustic demand testing is used to determine the necessary amount of caustic required to neutralize species present in the Hanford tank waste and obtain a target molarity of free hydroxide for tank corrosion control. The presence and quantity of hydroxide-consuming analytes are just as important in determining the caustic demand as is the amount of free hydroxide present. No single data point can accurately predict whether a satisfactory hydroxide level is being met, as it is dependent on multiple factors (e.g., free hydroxide, buffers, amphoteric metal hydroxides, bicarbonate, etc.). This enclosure contains the caustic demand, scanning electron microscopy (SEM), polarized light microscopy (PLM), and X-ray diffraction (XRD) analysis for the tank 241-AX-101 (AX-101) and 241-AX-103 (AX-103) samples. The work was completed to fulfill a customer request outlined in the test plan, WRPS-1505529, ''Test Plan and Procedure for Caustic Demand Testing on Tank 241-AX-101 and Tank 241-AX-103 Archive Samples.'' The work results will provide a baseline to support planned retrieval of AX-101 and AX-103.

Test Results for Caustic Demand Measurements on Tank 241-AX-101 and Tank 241-AX-103 Archive Samples

Energy Technology Data Exchange (ETDEWEB)

Doll, Stephanie R. [Washington River Protection Solutions, Richland, WA (United States); Bolling, Stacie D. [Washington River Protection Solutions, Richland, WA (United States)

2016-07-14

Caustic demand testing is used to determine the necessary amount of caustic required to neutralize species present in the Hanford tank waste and obtain a target molarity of free hydroxide for tank corrosion control. The presence and quantity of hydroxide-consuming analytes are just as important in determining the caustic demand as is the amount of free hydroxide present. No single data point can accurately predict whether a satisfactory hydroxide level is being met, as it is dependent on multiple factors (e.g., free hydroxide, buffers, amphoteric metal hydroxides, bicarbonate, etc.). This enclosure contains the caustic demand, scanning electron microscopy (SEM), polarized light microscopy (PLM), and X-ray diffraction (XRD) analysis for the tank 241-AX-101 (AX-101) and 241-AX-103 (AX-103) samples. The work was completed to fulfill a customer request outlined in the test plan, WRPS-1505529, “Test Plan and Procedure for Caustic Demand Testing on Tank 241-AX-101 and Tank 241-AX-103 Archive Samples.” The work results will provide a baseline to support planned retrieval of AX-101 and AX-103.

IMAGE-PLANE ANALYSIS OF n-POINT-MASS LENS CRITICAL CURVES AND CAUSTICS

Energy Technology Data Exchange (ETDEWEB)

Danek, Kamil; Heyrovský, David, E-mail: kamil.danek@utf.mff.cuni.cz, E-mail: heyrovsky@utf.mff.cuni.cz [Institute of Theoretical Physics, Faculty of Mathematics and Physics, Charles University in Prague (Czech Republic)

2015-06-10

The interpretation of gravitational microlensing events caused by planetary systems or multiple stars is based on the n-point-mass lens model. The first planets detected by microlensing were well described by the two-point-mass model of a star with one planet. By the end of 2014, four events involving three-point-mass lenses had been announced. Two of the lenses were stars with two planetary companions each; two were binary stars with a planet orbiting one component. While the two-point-mass model is well understood, the same cannot be said for lenses with three or more components. Even the range of possible critical-curve topologies and caustic geometries of the three-point-mass lens remains unknown. In this paper we provide new tools for mapping the critical-curve topology and caustic cusp number in the parameter space of n-point-mass lenses. We perform our analysis in the image plane of the lens. We show that all contours of the Jacobian are critical curves of re-scaled versions of the lens configuration. Utilizing this property further, we introduce the cusp curve to identify cusp-image positions on all contours simultaneously. In order to track cusp-number changes in caustic metamorphoses, we define the morph curve, which pinpoints the positions of metamorphosis-point images along the cusp curve. We demonstrate the usage of both curves on simple two- and three-point-mass lens examples. For the three simplest caustic metamorphoses we illustrate the local structure of the image and source planes.

Design and implementation of a caustic flooding EOR pilot at Court Bakken heavy oil reservoir

Energy Technology Data Exchange (ETDEWEB)

Xie, J.; Chung, B.; Leung, L. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[Nexen Inc., Calgary, AB (Canada)

2008-10-15

Successful waterflooding has been ongoing since 1988 at the Court Bakken heavy oil field in west central Saskatchewan. There are currently 20 injectors and 28 active oil producers in the Court main unit which is owned by Nexen and Pengrowth. The Court pool has an estimated 103.8 mmbbl of original oil in place (OOIP), of which 24 per cent has been successfully recovered after 20 years of waterflooding. A high-level enhanced oil recovery (EOR) screening study was conducted to evaluate other EOR technologies for a heavy oil reservoir of this viscosity range (17 degrees API). Laboratory studies showed that caustic flooding may enhance oil recovery after waterflooding at the Court Bakken heavy oil pool. A single well test demonstrated that caustic injection effectively reduced residual oil saturation. A sector model reservoir simulation revealed that caustic flood could achieve 9 per cent incremental oil recovery in the pilot area. Following the promising laboratory results, a successful caustic flood pilot was implemented at Court heavy oil pool where the major challenges encountered were low reservoir pressure and water channeling. 6 refs., 2 tabs., 6 figs.

EFRT M-12 Issue Resolution: Caustic-Leach Rate Constants from PEP and Laboratory-Scale Tests

Energy Technology Data Exchange (ETDEWEB)

Mahoney, Lenna A.; Rassat, Scot D.; Eslinger, Paul W.; Aaberg, Rosanne L.; Aker, Pamela M.; Golovich, Elizabeth C.; Hanson, Brady D.; Hausmann, Tom S.; Huckaby, James L.; Kurath, Dean E.; Minette, Michael J.; Sundaram, S. K.; Yokuda, Satoru T.

2010-01-01

Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed, constructed and operated as part of a plan to respond to issue M12, “Undemonstrated Leaching Processes” of the External Flowsheet Review Team (EFRT) issue response plan.( ) The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. The PEP also includes non-prototypic ancillary equipment to support the core processing. The work described in this report addresses caustic leaching under WTP conditions, based on tests performed with a Hanford waste simulant. Because gibbsite leaching kinetics are rapid (gibbsite is expected to be dissolved by the time the final leach temperature is reached), boehmite leach kinetics are the main focus of the caustic-leach tests. The tests were completed at the laboratory-scale and in the PEP, which is a 1/4.5-scale mock-up of key PTF process equipment. Two laboratory-scale caustic-leach tests were performed for each of the PEP runs. For each PEP run, unleached slurry was taken from the PEP caustic-leach vessel for one batch and used as feed for both of the corresponding laboratory-scale tests.

On the behaviour of test matter in the neighbourhood of caustics of homogeneous cosmological models

International Nuclear Information System (INIS)

Paul, H.G.

1983-01-01

Using power asymptotes for the metric of the BIANCHI types I, V, VII 0 , VIII and IX the intensity of geodesic focused scalar test matter is calculated in the neighbourhood of the caustic singularity of these space-time models. In all considered BIANCHI types there is a caustic diffraction with a diffraction field bounded by regions of extinction depending on the structure of the gravitational lense. (author)

Mill Integration-Pulping, Stream Reforming and Direct Causticization for Black Liquor Recovery

Energy Technology Data Exchange (ETDEWEB)

Adriaan van Heiningen

2007-06-30

MTCI/StoneChem developed a steam reforming, fluidized bed gasification technology for biomass. DOE supported the demonstration of this technology for gasification of spent wood pulping liquor (or 'black liquor') at Georgia-Pacific's Big Island, Virginia mill. The present pre-commercial R&D project addressed the opportunities as well as identified negative aspects when the MTCI/StoneChem gasification technology is integrated in a pulp mill production facility. The opportunities arise because black liquor gasification produces sulfur (as H{sub 2}S) and sodium (as Na{sub 2}CO{sub 3}) in separate streams which may be used beneficially for improved pulp yield and properties. The negative aspect of kraft black liquor gasification is that the amount of Na{sub 2}CO{sub 3} which must be converted to NaOH (the so called causticizing requirement) is increased. This arises because sulfur is released as Na{sub 2}S during conventional kraft black liquor recovery, while during gasification the sodium associated Na{sub 2}S is partly or fully converted to Na{sub 2}CO{sub 3}. The causticizing requirement can be eliminated by including a TiO{sub 2} based cyclic process called direct causticization. In this process black liquor is gasified in the presence of (low sodium content) titanates which convert Na{sub 2}CO{sub 3} to (high sodium content) titanates. NaOH is formed when contacting the latter titanates with water, thereby eliminating the causticizing requirement entirely. The leached and low sodium titanates are returned to the gasification process. The project team comprised the University of Maine (UM), North Carolina State University (NCSU) and MTCI/ThermoChem. NCSU and MTCI are subcontractors to UM. The principal organization for the contract is UM. NCSU investigated the techno-economics of using advanced pulping techniques which fully utilize the unique cooking liquors produced by steam reforming of black liquor (Task 1). UM studied the kinetics and

Gravitational microlensing - Powerful combination of ray-shooting and parametric representation of caustics

Science.gov (United States)

Wambsganss, J.; Witt, H. J.; Schneider, P.

1992-01-01

We present a combination of two very different methods for numerically calculating the effects of gravitational microlensing: the backward-ray-tracing that results in two-dimensional magnification patterns, and the parametric representation of caustic lines; they are in a way complementary to each other. The combination of these methods is much more powerful than the sum of its parts. It allows to determine the total magnification and the number of microimages as a function of source position. The mean number of microimages is calculated analytically and compared to the numerical results. The peaks in the lightcurves, as obtained from one-dimensional tracks through the magnification pattern, can now be divided into two groups: those which correspond to a source crossing a caustic, and those which are due to sources passing outside cusps. We determine the frequencies of those two types of events as a function of the surface mass density, and the probability distributions of their magnitudes. We find that for low surface mass density as many as 40 percent of all events in a lightcurve are not due to caustic crossings, but rather due to passings outside cusps.

P-Area Acid/Caustic Basin groundwater monitoring report. First quarter 1995

International Nuclear Information System (INIS)

Chase, J.A.

1995-06-01

During first quarter 1995, groundwater from the six PAC monitoring wells at the P-Area Acid/Caustic Basin was analyzed for herbicides/pesticides, indicator parameters, metals, nitrate, adionuclide indicators, and other constituents. Monitoring results that exceeded the final Primary Drinking Water Standards (PDWS) or the Savannah River Site (SRS) flagging criteria or turbidity standard during the quarter are discussed in this report. During first quarter 1995, no constituents exceeded the final PDWS. Aluminum exceeded its SRS Flag 2 criterion in all six PAC wells. Iron and manganese exceeded Flag 2 criteria in three wells, while turbidity was elevated in one well. Groundwater flow direction and rate in the water table beneath the P-Area Acid/Caustic Basin were similar to past quarters

Unmodified versus caustics-impregnated carbons for control of hydrogen sulfide emissions from sewage treatment plants

Energy Technology Data Exchange (ETDEWEB)

Bandosz, T.J.; Bagreev, A.; Adib, F.; Turk, A.

2000-03-15

Unmodified and caustic-impregnated carbons were compared as adsorbents for hydrogen sulfide in the North River Water Pollution Control Plant in New York City over a period of 2 years. The carbons were characterized using accelerated H{sub 2}S breakthrough capacity tests, sorption of nitrogen, potentiometric titration, and thermal analysis. The accelerated laboratory tests indicate that the initial capacity of caustic-impregnated carbons exceeds that of unmodified carbon, but the nature of real-life challenge streams, particularly their lower H{sub 2}S concentrations, nullifies this advantage. As the caustic content of the impregnated carbon is consumed, the situation reverses, and the unmodified carbon becomes more effective. When the concentration of H{sub 2}S is low, the developed surface area and pore volume along with the affinity to retain water create a favorable environment for dissociative adsorption of hydrogen sulfide and its oxidation to elemental sulfur, S{sup 4+}, and S{sup 6+}. In the case of the caustic carbon, the catalytic impact of the carbon surface is limited, and its good performance lasts only while active base is present. The results also show the significant differences in performance of unmodified carbons due to combined effects of their porosity and surface chemistry.

Caustic Ingestion in the Elderly: Influence of Age on Clinical Outcome

Directory of Open Access Journals (Sweden)

Blazena Caganova

2017-10-01

Full Text Available Caustic poisonings are still associated with many fatalities. Studies focusing on the elderly are rare. The purpose of the present study was to compare the clinical outcomes of caustic ingestion injury in elderly and non-elderly adults with regard to gender, intent of exposure, substance ingested, severity of mucosal injury, complications, and mortality. Caustic substance exposures reported to the National Toxicological Information Centre in Slovakia during 1998–2015 were reviewed retrospectively. The patients were divided into two groups: the non-elderly (<60 years and elderly adults (≥60 years. The mortality rate in the elderly was significantly higher (elderly 23.0% vs. non-elderly 11.3%; p = 0.041. The risk of fatal outcome in the elderly was increased by acid ingestion (OR = 7.822; p = 0.002, particularly hydrochloric acid (OR = 5.714, p = 0.006. The incidence of respiratory complications was almost two times higher in the elderly was 31.1% vs. 17.4% for the non-elderly (p = 0.037. Respiratory complications significantly correlated with an increased mortality rate (p = 0.001 in the elderly whereas there was no association between GI complications and mortality in the elderly (p = 0.480. Elderly patients with respiratory complications had the poorest clinical outcomes. The highest risk of complications and fatalities was observed in patients after hydrochloric acid ingestion.

Benign hepatic portal venous gas following caustic ingestion

International Nuclear Information System (INIS)

Lewin, Maite; Tubiana, Jean-Michel; Pocard, Marc; Caplin, Scott; Parc, Rolland; Blain, Antoine

2002-01-01

Hepatic portal vein gas has been documented in numerous conditions and is traditionally regarded as a poor prognostic sign. There are, however, several reports of portal vein gas with a benign course. We report the first case of transient hepatic portal vein gas secondary to the ingestion of a caustic substance. The literature of hepatic portal vein gas in benign disease is reviewed. (orig.)

A geochemical module for "AMDTreat" to compute caustic quantity, effluent quantity, and sludge volume

Science.gov (United States)

Cravotta,, Charles A.; Parkhurst, David L.; Means, Brent P; McKenzie, Bob; Morris, Harry; Arthur, Bill

2010-01-01

Treatment with caustic chemicals typically is used to increase pH and decrease concentrations of dissolved aluminum, iron, and/or manganese in largevolume, metal-laden discharges from active coal mines. Generally, aluminum and iron can be removed effectively at near-neutral pH (6 to 8), whereas active manganese removal requires treatment to alkaline pH (~10). The treatment cost depends on the specific chemical used (NaOH, CaO, Ca(OH)2, Na2CO3, or NH3) and increases with the quantities of chemical added and sludge produced. The pH and metals concentrations do not change linearly with the amount of chemical added. Consequently, the amount of caustic chemical needed to achieve a target pH and the corresponding effluent composition and sludge volume can not be accurately determined without empirical titration data or the application of geochemical models to simulate the titration of the discharge water with caustic chemical(s). The AMDTreat computer program (http://amd.osmre.gov/ ) is widely used to compute costs for treatment of coal-mine drainage. Although AMDTreat can use results of empirical titration with industrial grade caustic chemicals to compute chemical costs for treatment of net-acidic or net-alkaline mine drainage, such data are rarely available. To improve the capability of AMDTreat to estimate (1) the quantity and cost of caustic chemicals to attain a target pH, (2) the concentrations of dissolved metals in treated effluent, and (3) the volume of sludge produced by the treatment, a titration simulation is being developed using the geochemical program PHREEQC (wwwbrr.cr.usgs.gov/projects/GWC_coupled/phreeqc/) that will be coupled as a module to AMDTreat. The simulated titration results can be compared with or used in place of empirical titration data to estimate chemical quantities and costs. This paper describes the development, evaluation, and potential utilization of the PHREEQC titration module for AMDTreat.

F-Area Acid/Caustic Basin groundwater monitoring report. Second quarter 1994

International Nuclear Information System (INIS)

1994-09-01

During second quarter 1994, samples from the FAC monitoring wells at the F-Area Acid/Caustic Basin were collected and analyzed for herbicides/pesticides, indicator parameters, metals, nitrate, radionuclide indicators, volatile organic compounds, and other constituents. Piezometer FAC 5P and monitoring well FAC 6 were dry and could not be sampled. Analytical results that exceeded final Primary Drinking Water Standards (PDWS), other Savannah River Site (SRS) Flag 2 criteria, or the SRS turbidity standard of 50 NTU during the quarter were as follows: gross alpha exceeded the final PDWS and aluminum, iron, manganese, and total organic halogens exceeded the SRS Flag 2 criteria in one or more of the FAC wells. Turbidity exceeded the SRS standard in well FAC 3. Groundwater flow direction and rate in the water table beneath the F-Area Acid/Caustic Basin were similar to past quarters

The wire optical test: a thorough analytical study in and out of caustic surface, and advantages of a dynamical adaptation

Science.gov (United States)

Alejandro Juárez-Reyes, Salvador; Sosa-Sánchez, Citlalli Teresa; Silva-Ortigoza, Gilberto; de Jesús Cabrera-Rosas, Omar; Espíndola-Ramos, Ernesto; Ortega-Vidals, Paula

2018-03-01

Among the best known non-interferometric optical tests are the wire test, the Foucault test and Ronchi test with a low frequency grating. Since the wire test is the seed to understand the other ones, the aim of the present work is to do a thorough study of this test for a lens with symmetry of revolution and to do this study for any configuration of the object and detection planes where both planes could intersect: two, one or no branches of the caustic region (including the marginal and paraxial foci). To this end, we calculated the vectorial representation for the caustic region, and we found the analytical expression for the pattern; we report that the analytical pattern explicitly depends on the magnitude of a branch of the caustic. With the analytical pattern we computed a set of simulations of a dynamical adaptation of the optical wire test. From those simulations, we have done a thorough analysis of the topological structure of the pattern; so we explain how the multiple image formation process and the image collapse process take place for each configuration, in particular, when both the wire and the detection planes are placed inside the caustic region, which has not been studied before. For the first time, we remark that not only the intersections of the object and detection planes with the caustic are important in the change of pattern topology; but also the projection of the intersection between the caustic and the object plane mapped onto the detection plane; and the virtual projection of the intersection between the caustic and the detection plane mapped onto the object plane. We present that for the new configurations of the optical system, the wire image is curves of the Tschirnhausen’s cubic, the piriform and the deformed eight-curve types.

The economic pre-treatment of coal mine drainage water with caustic and ozone.

Science.gov (United States)

Boyden, B H; Nador, L; Addleman, S; Jeston, L

2017-09-01

Coal mine drainage waters are low in pH with varying amounts of iron and manganese and are generally brackish. The Austar Coal Mine in NSW, Australia, sought alternatives to their current lime dosing as the pre-treatment before the downstream reverse osmosis plant. Undesirable operating aspects of the current system include manganese and gypsum scaling/fouling, the need for anti-scalants and reduced water recovery. Thirteen processes for acid mine drainage were initially considered. The preferred process of caustic and ozone for Mn(II) oxidation was pilot tested at up to 0.74 kL/hr at the mine site. Under proper conditions and no aeration, about 81 per cent of the Fe could be removed (initially at 156 mg/L) as green rust. Supplemental aeration followed first-order kinetics and allowed 99.9 per cent Fe(II) oxidation and removal but only with a hydraulic residence time of about 47 minutes. The addition of supplemental Cu catalyst improved Fe removal. Ozone applied after caustic was effective in stoichiometrically oxidising recalcitrant Mn(II) and any remaining Fe(II). Control of the ozonation was achieved using the oxidation reduction potential during oxidation of the Mn(II) species. The use of caustic, followed by ozone, proved economically comparable to the current lime pre-treatment.

Washing and caustic leaching of Hanford tank sludge: Results of FY 1997 studies

International Nuclear Information System (INIS)

Lumetta, G.J.; Burgeson, I.E.; Wagner, M.J.; Liu, J.; Chen, Y.L.

1997-08-01

The current plan for remediating the Hanford tank farms consists of waste retrieval, pretreatment, treatment (immobilization), and disposal. The tank wastes will be partitioned into high-level and low-level fractions. The HLW will be immobilized in a borosilicate glass matrix; the resulting glass canisters will then be disposed of in a geologic repository. Because of the expected high cost of HLW vitrification and geologic disposal, pretreatment processes will be implemented to reduce the volume of immobilized high-level waste (IHLW). Caustic leaching (sometimes referred to as enhanced sludge washing or ESW) represents the baseline method for pretreating Hanford tank sludges. Caustic leaching is expected to remove a large fraction of the Al, which is present in large quantities in Hanford tank sludges. A significant portion of the P is also expected to be removed from the sludge by metathesis of water-insoluble metal phosphates to insoluble hydroxides and soluble Na 3 PO 4 . Similar metathesis reactions can occur for insoluble sulfate salts, allowing the removal of sulfate from the HLW stream. This report describes the sludge washing and caustic leaching tests performed at the Pacific Northwest National Laboratory in FY 1996. The sludges used in this study were taken from Hanford tanks AN-104, BY-108, S-101, and S-111

Caustic-Side Solvent Extraction: Prediction of Cesium Extraction from Actual Wastes and Actual Waste Simulants

International Nuclear Information System (INIS)

Delmau, L.H.; Haverlock, T.J.; Sloop, F.V. Jr.; Moyer, B.A.

2003-01-01

This report presents the work that followed the CSSX model development completed in FY2002. The developed cesium and potassium extraction model was based on extraction data obtained from simple aqueous media. It was tested to ensure the validity of the prediction for the cesium extraction from actual waste. Compositions of the actual tank waste were obtained from the Savannah River Site personnel and were used to prepare defined simulants and to predict cesium distribution ratios using the model. It was therefore possible to compare the cesium distribution ratios obtained from the actual waste, the simulant, and the predicted values. It was determined that the predicted values agree with the measured values for the simulants. Predicted values also agreed, with three exceptions, with measured values for the tank wastes. Discrepancies were attributed in part to the uncertainty in the cation/anion balance in the actual waste composition, but likely more so to the uncertainty in the potassium concentration in the waste, given the demonstrated large competing effect of this metal on cesium extraction. It was demonstrated that the upper limit for the potassium concentration in the feed ought to not exceed 0.05 M in order to maintain suitable cesium distribution ratios

Solvent polarity effects on supramolecular chirality of a polyfluorene-thiophene copolymer.

Science.gov (United States)

Hirahara, Takashi; Yoshizawa-Fujita, Masahiro; Takeoka, Yuko; Rikukawa, Masahiro

2018-06-01

This study demonstrates the supramolecular chirality control of a conjugated polymer via solvent polarity. We designed and synthesized a chiral polyfluorene-thiophene copolymer having two different chiral side chains at the 9-position of the fluorene unit. Chiral cyclic and alkyl ethers with different polarities were selected as the chiral side chains. The sign of the circular dichroism spectra in the visible wavelength region was affected by the solvent system, resulting from the change of supramolecular structure. The estimation of the solubility parameter revealed that the solubility difference of the side chains contributed to the change of the circular dichroism sign, which was also observed in spin-coated films prepared from good solvents having different polarities. © 2018 Wiley Periodicals, Inc.

Washing and Caustic Leaching of Hanford Tank Sludge: Results of FY 1998 Studies

Energy Technology Data Exchange (ETDEWEB)

GJ Lumetta; BM Rapko; J Liu; DJ Temer; RD Hunt

1998-12-11

Sludge washing and parametric caustic leaching tests were performed on sludge samples tiom five Hanford tanks: B-101, BX-1 10, BX-112, C-102, and S-101. These studies examined the effects of both dilute hydroxide washing and caustic leaching on the composition of the residual sludge solids. ` Dilute hydroxide washing removed from <1 to 25% of the Al, -20 to 45% of the Cr, -25 to 97% of the P, and 63 to 99% of the Na from the Hdord tank sludge samples examined. The partial removal of these elements was likely due to the presence of water-soluble sodium salts of aluminate, chromate, hydroxide, nitrate, nitrite, and phosphate, either in the interstitial liquid or as dried salts.

Stress corrosion cracking susceptibility of steam generator tubing on secondary side in restricted flow areas

International Nuclear Information System (INIS)

Fulger, M.; Lucan, D.; Radulescu, M.; Velciu, L.

2003-01-01

Nuclear steam generator tubes operate in high temperature water and on the secondary side in restricted flow areas many nonvolatile impurities accidentally introduced into circuit tend to concentrate. The concentration process leads to the formation of highly aggressive alkaline or acid solutions in crevices, and these solutions can cause stress corrosion cracking (SCC) on stressed tube materials. Even though alloy 800 has shown to be highly resistant to general corrosion in high temperature water, it has been found that the steam generator tubes may crack during service from the primary and/or secondary side. Stress corrosion cracking is still a serious problem occurring on outside tubes in operating steam generators. The purpose of this study was to evaluate the environmental factors affecting the stress corrosion cracking of steam generators tubing. The main test method was the exposure for 1000 hours into static autoclaves of plastically stressed C-rings of Incoloy 800 in caustic solutions (10% NaOH) and acidic chloride solutions because such environments may sometimes form accidentally in crevices on secondary side of tubes. Because the kinetics of corrosion of metals is indicated by anodic polarization curves, in this study, some stressed specimens were anodically polarized in caustic solutions in electrochemical cell, and other in chloride acidic solutions. The results presented as micrographs, potentiokinetic curves, and electrochemical parameters have been compared to establish the SCC behavior of Incoloy 800 in such concentrated environments. (authors)

Caustic ingestion and esophageal function

Energy Technology Data Exchange (ETDEWEB)

Cadranel, S.; Di Lorenzo, C.; Rodesch, P.; Piepsz, A.; Ham, H.R. (Children University Hospital, Brussels (Belgium))

1990-02-01

The aim of the present study was to investigate esophageal motor function by means of krypton-81m esophageal transit scintigraphy and to compare the results with the functional and morphological data obtained by means of triple lumen manometry and endoscopy. In acute and subacute stages of the disease, all clinical, anatomical, and functional parameters were in good agreement, revealing significant impairment. In chronic stages, the severity of the dysphagia was not correlated to the importance of the residual stenosis. Conversely, 81mKr esophageal transit and manometric's findings were in good agreement with the clinical symptoms, during the entire follow-up period ranging between 3 months to 7 years. The 81mKr test is undoubtedly the easiest and probably the most physiological technique currently available for long-term functional evaluation of caustic esophagitis.

The Efficacy of Mesenchymal Stem Cell Transplantation in Caustic Esophagus Injury: An Experimental Study

Directory of Open Access Journals (Sweden)

Murat Kantarcioglu

2014-01-01

Full Text Available Introduction. Ingestion of corrosive substances may lead to stricture formation in esophagus as a late complication. Full thickness injury seems to exterminate tissue stem cells of esophagus. Mesenchymal stem cells (MSCs can differentiate into specific cell lineages and have the capacity of homing in sites of injury. Aim and Methods. We aimed to investigate the efficacy of MSC transplantation, on prevention of esophageal damage and stricture formation after caustic esophagus injury in rats. 54 rats were allocated into four groups; 4 rats were sacrificed for MSC production. Group 1, untreated controls (n: 10. Group 2, membrane labeled MSCs-treated rats (n: 20. Group 3, biodistribution of fluorodeoxyglucose labeled MSCs via positron emission tomography (PET imaging (n: 10. Group 4, sham operated (n: 10. Standard caustic esophageal burns were created and MSCs were transplanted 24 hours after. All rats were sacrificed at the 21st days. Results. PET scan images revealed the homing behavior of MSCs to the injury site. The histopathology damage score was not significantly different from controls. However, we demonstrated Dil labeled epithelial and muscle cells which were originating from transplanted MSCs. Conclusion. MSC transplantation after caustic esophageal injury may be a helpful treatment modality; however, probably repeated infusions are needed.

Solvent purification with high-porosity (macroreticular) ion-exchange resin

International Nuclear Information System (INIS)

McKibben, J.M.

Numerous solvent degradation products exist in all of our process solvents that are not efficiently removed in the routine solvent washing operation. Tests indicate that a relatively new type of resin - variously called high-porosity, macroreticular, or macroporous resin - removes at least some of these persistent chemicals and substantially improves the quality of any TBP process solvent. A plant test is proposed for the purification of the first cycle solvent of the HM process, in which a loop will be installed to draw a small side stream of solvent from the washed solvent hold tank (904), pass it through a 2.7 ft 3 resin column, and return it to the same tank

Inertial-particle dynamics in turbulent flows: caustics, concentration fluctuations and random uncorrelated motion

International Nuclear Information System (INIS)

Gustavsson, K; Mehlig, B; Meneguz, E; Reeks, M

2012-01-01

We have performed numerical simulations of inertial particles in random model flows in the white-noise limit (at zero Kubo number, Ku = 0) and at finite Kubo numbers. Our results for the moments of relative inertial-particle velocities are in good agreement with recent theoretical results (Gustavsson and Mehlig 2011a) based on the formation of phase-space singularities in the inertial-particle dynamics (caustics). We discuss the relation between three recent approaches describing the dynamics and spatial distribution of inertial particles suspended in turbulent flows: caustic formation, real-space singularities of the deformation tensor and random uncorrelated motion. We discuss how the phase- and real-space singularities are related. Their formation is well understood in terms of a local theory. We summarise the implications for random uncorrelated motion. (paper)

Influence of microstructure on stress corrosion cracking of mild steel in synthetic caustic-nitrate nuclear waste solution

International Nuclear Information System (INIS)

Sarafian, P.G.

1975-12-01

The influence of alloy microstructure on stress corrosion cracking of mild steel in caustic-nitrate synthetic nuclear waste solutions was studied. An evaluation was made of the effect of heat treatment on a representative material (ASTM A 516 Grade 70) used in the construction of high activity radioactive waste storage tanks at Savannah River Plant. Several different microstructures were tested for susceptibility to stress corrosion cracking. Precracked fracture specimens loaded in either constant load or constant crack opening displacement were exposed to a variety of caustic-nitrate and nitrate solutions. Results were correlated with the mechanical and corrosion properties of the microstructures. Crack velocity and crack arrest stress intensity were found to be related to the yield strength of the steel microstructures. Fractographic evidence indicated pH depletion and corrosive crack tip chemistry conditions even in highly caustic solutions. Experimental results were compatible with crack growth by a strain-assisted anodic dissolution mechanism; however, hydrogen embrittlement also was considered possible

Extraction of caustic potash from spent tea for biodiesel Production

Science.gov (United States)

Sulaiman, Sarina; Faiz Che Fisol, Ahmad; Sharikh, Atikah Mohamed; Noraini Jimat, Dzun; Jamal, Parveen

2018-01-01

Biodiesel is an alternative to non-renewable fossil fuels due to its low gas emission and economical value. This study aims to extract caustic potash (KOH) from spent tea and to optimize the transesterfication process based on parameters such as amount of catalyst, reaction temperature and methanol to oil ratio. The spent tea was first dried at 60°C prior to calcination at 600°C for two hours. Caustic Potash were extracted from the calcined spent tea. The transesterification process was done based on Design of Experiments (DOE) to study the effects of amount of catalyst ranging from 0.5 wt % to 2.5 wt %, reaction temperature from 55°C to 65°C and methanol to oil ratio from 6:1 to 12:1 at a constant agitation rate of 300 rpm for three hours. The calcined spent tea produced was recorded the highest at 54.3 wt % and the extracted catalyst was 2.4 wt %. The optimized biodiesel yield recorded was 56.95% at the optimal conditions of 2.5 wt % amount of catalyst, 65°C reaction temperature and 9:1 methanol to oil ratio.

Impact of Strontium Nitrate and Sodium Permanganate Addition on Solid-Liquid Separation of SRS High Level Waste

International Nuclear Information System (INIS)

Poirier, M.R.

2002-01-01

As a pretreatment step for the caustic side solvent extraction (CSSX) flowsheet, the process contacts the incoming salt solution containing entrained sludge with monosodium titanate (MST) to adsorb strontium and actinides. An operation filters the resulting slurry to remove the sludge and MST. Previous work for the River Protection Program at Hanford suggests that addition of strontium nitrate and sodium permanganate for strontium and actinide removal, rather than MST, improves the filtration rate for comparable waste streams

Preliminary study of efficacy of hyaluronic acid on caustic esophageal burns in an experimental rat model.

Science.gov (United States)

Cevik, Muazez; Demir, Tuncer; Karadag, Cetin Ali; Ketani, Muzaffer Aydin; Celik, Hakim; Kaplan, Davut Sinan; Boleken, Mehmet Emin

2013-04-01

The aim of this study was to investigate the effectiveness of hyaluronic acid on the prevention of esophageal damage and stricture formation after experimental caustic (alkaline) esophageal injury in rats. Twenty-one Wistar albino rats were randomly divided into three groups. A caustic esophageal burn was created following the Gehanno model: Group l (n=7) underwent operation, but no injury; Group 2 (n=7) was injured and left untreated; and Group 3 (n=7) was injured and treated with hyaluronic acid, first topically and then orally by gavage (2×0.3mL; 12.5mg/mL for 7days). The caustic esophageal burn was created by instilling 25% NaOH into the distal esophagus. All rats were euthanized on day 22 for evaluation. The efficacy of hyaluronic acid treatment was assessed histopathologically and biochemically via blood determination of the total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), and sulfhydryl group (SH) and lipid hydroperoxidase (LOOH) levels. Statistical analyses were performed. Weight gain was significantly lower in Group 2 than in the other two groups (POSI, and SH and LOOH levels were higher in Group 2 than in the other two groups. The mean stenosis index, inflammation, TAS, SH and OSI in Group 2 were significantly different than those in the other two groups (P<0.05). Hyaluronic acid treatment is effective in treating damage and preventing strictures after caustic esophageal burn in rats. Copyright © 2013 Elsevier Inc. All rights reserved.

K-Area Acid/Caustic Basin groundwater monitoring report

International Nuclear Information System (INIS)

Thompson, C.Y.

1992-09-01

During second quarter 1992, samples from the seven older KAC monitoring wells at the K-Area Acid/Caustic Basin were analyzed for herbicides, indicator parameters, major ions, pesticides, radionuclides, turbidity, and other constituents. New wells FAC 8 and 9 received the first of four quarters of comprehensive analyses and GC/MS VOA (gas chromatograph/ mass spectrometer volatile organic analyses). Monitoring results that exceeded the US Environmental Protection Agency's Primary Drinking Water Standards (PDWS) or the Savannah River Site (SRS) flagging criteria or turbidity standards during the quarter are discussed in this report

PEP Integrated Test D Run Report Caustic and Oxidative Leaching in UFP-VSL-T02A

Energy Technology Data Exchange (ETDEWEB)

Sevigny, Gary J.; Bredt, Ofelia P.; Burns, Carolyn A.; Kurath, Dean E.; Geeting, John GH; Golovich, Elizabeth C.; Guzman-Leong, Consuelo E.; Josephson, Gary B.

2009-12-11

Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed, constructed and operated as part of a plan to respond to issue M12, "Undemonstrated Leaching Processes" of the External Flowsheet Review Team (EFRT) issue response plan. The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. The PEP also includes non-prototypic ancillary equipment to support the core processing. Two operating scenarios are currently being evaluated for the ultrafiltration process (UFP) and leaching operations. The first scenario (Test B and D) has caustic leaching performed in the UFP-2 ultrafiltration feed vessels (i.e., vessel UFP-VSL-T02A in the PEP and vessels UFP-VSL-00002A and B in the WTP PTF). The second scenario (Test A) has caustic leaching conducted in the UFP-1 ultrafiltration feed preparation vessels (i.e., vessels UFP-VSL-T01A and B in the PEP and vessels UFP VSL-00001A and B in the WTP PTF). In Test D, 19M sodium hydroxide (NaOH, caustic) was added to the waste slurry in the UFP VSL T02 vessel after the solids were concentrated to ~20% undissolved solids. The NaOH was added to leach solid aluminum compounds (e.g., gibbsite, boehmite). Caustic addition is followed by heating to 85°C using direct injection of steam to accelerate the leach process. The main difference of Test D compared to Test B is that the leach temperature is 85°C for 24 hrs as compared to 100°C for 12 hours. The other difference is the Test D simulant had Cr in the

Interactive Dynamic Volume Illumination with Refraction and Caustics.

Science.gov (United States)

Magnus, Jens G; Bruckner, Stefan

2018-01-01

In recent years, significant progress has been made in developing high-quality interactive methods for realistic volume illumination. However, refraction - despite being an important aspect of light propagation in participating media - has so far only received little attention. In this paper, we present a novel approach for refractive volume illumination including caustics capable of interactive frame rates. By interleaving light and viewing ray propagation, our technique avoids memory-intensive storage of illumination information and does not require any precomputation. It is fully dynamic and all parameters such as light position and transfer function can be modified interactively without a performance penalty.

Caustic stress corrosion cracking of Inconel-600, Incoloy-800, and Type 304 stainless steel

International Nuclear Information System (INIS)

Theus, G.J.

1976-01-01

High-temperature electrochemical tests have resulted in the stress corrosion cracking of Inconel-600 and Incoloy-800 (registered trademarks, International Nickel Company), and Type 304 stainless steel in caustic solutions. Results show that stress corrosion cracking of these alloys can be prevented or accelerated by varying their electrochemical potential. To a certain extent, the same effect can be achieved by altering the gas atmosphere above the test solution from a pure nitrogen cover gas to a mixture of 5 percent H 2 and 95 percent N 2 . The effect of the cover gas can then be negated by adjusting the specimen's electrochemical potential either to cause or to inhibit stress corrosion cracking. Some specifics of the test results reveal that in deoxygenated caustic solutions, Inconel-600 cracks intergranularly at mildly anodic potentials; Incoloy-800 cracks transgranularly at reduced potentials (at or near the open circuit potential) and intergranularly at highly oxidizing potentials; and cracking is mixed (transgranular/intergranular) for Type 304 stainless steel at or near the open circuit potential. The severity of cracking for both Inconel-600 and Incoloy-800 in deoxygenated caustic solutions is reduced by giving the materials a simulated post-weld heat treatment (1150 0 F for 18 h). Test results on Inconel-600 show that high-carbon (0.06 percent) material cracks less severely than low-carbon (0.02 percent) material, in both the simulated post-weld heat-treated condition and the mill-annealed condition

Comparison of ultrasound-assisted and traditional caustic leaching of spent cathode carbon (SCC) from aluminum electrolysis.

Science.gov (United States)

Xiao, Jin; Yuan, Jie; Tian, Zhongliang; Yang, Kai; Yao, Zhen; Yu, Bailie; Zhang, Liuyun

2018-01-01

The spent cathode carbon (SCC) from aluminum electrolysis was subjected to caustic leaching to investigate the different effects of ultrasound-assisted and traditional methods on element fluorine (F) leaching rate and leaching residue carbon content. Sodium hydroxide (NaOH) dissolved in deionized water was used as the reaction system. Through single-factor experiments and a comparison of two leaching techniques, the optimum F leaching rate and residue carbon content for ultrasound-assisted leaching process were obtained at a temperature of 70°C, residue time of 40min, initial mass ratio of alkali to SCC (initial alkali-to-material ratio) of 0.6, liquid-to-solid ratio of 10mL/g, and ultrasonic power of 400W, respectively. Under the optimal conditions, the leaching residue carbon content was 94.72%, 2.19% larger than the carbon content of traditional leaching residue. Leaching wastewater was treated with calcium chloride (CaCl 2 ) and bleaching powder and the treated wastewater was recycled caustic solution. All in all, benefiting from advantage of the ultrasonication effects, ultrasound-assisted caustic leaching on spent cathode carbon had 55.6% shorter residue time than the traditional process with a higher impurity removal rate. Copyright © 2017 Elsevier B.V. All rights reserved.

Functionally Graded Ceramics Fabricated with Side-by-Side Tape Casting for Use in Magnetic Refrigeration

DEFF Research Database (Denmark)

Bulatova, Regina; Bahl, Christian; Andersen, Kjeld Bøhm

2015-01-01

Functionally graded ceramic tapes have been fabricated by a side-by-side tape casting technique. This study shows the possibility and describes the main principles of adjacent coflow of slurries resulting in formation of thin plates of graded ceramic material. Results showed that the small...... variations of solvent and binder system concentrations have a substantial effect on slurry viscosity. Varying these parameters showed that side-by-side tape casting with a well-defined interface area is possible for slurries with viscosities above 3500 mPa s at a casting shear rate of 3.3 s -1...... of developing this graded ceramic tape casting was applications of these specific magnetocaloric properties within the magnetic refrigeration technology....

The solvent extraction of cerium from sulphate solution - mini plant trials

International Nuclear Information System (INIS)

Soldenhoff, K.; Wilkins, D.; Ring, R.

1998-01-01

Full text: The Mt. Weld deposit in Western Australia has a complex rare earth mineralisation. The rare earth phosphate minerals, which include monazite, are amenable to conventional caustic cracking followed by hydrochloric acid dissolution of the trivalent rare earths. The presence of the mineral cerianite in the ore, which is unaffected by the alkali attack, results in rejection of a considerable proportion of the cerium to the acid leach residue. The recovery of cerium from a sulphate solution, resulting from the processing of such a residue, is the subject of the current paper. The liquor treated by solvent extraction contained 63 g L -1 rare earths and the cerium to total rare earth ratio was 75%. Other impurities, including Fe and Th, totalled 2000 ppm. A solvent mixture of commercially available extractants in a low aromatic content diluent was used to extract Ce 4+ selectively over the trivalent rare earths. Partial co-extraction of Fe and Th occurred but it was found that these elements were not easily stripped and therefore selective back extraction of cerium was possible. The cerium was stripped from the organic phase by hydrochloric acid and hydrogen peroxide. In continuous counter-current trials two extraction stages and three strip stages were used. In order to produce two grades of strip liquor, stripping was divided into two circuits. The first strip circuit consisting of a single stage, contained proportionally more of the trivalent rare earths. The second strip circuit, consisting of two stages, removed the remaining cerium with proportionally less of the rare earths. A bleed solvent stream was treated for removal of impurities to prevent build-up in the solvent. In the continuous counter current trials, 95% Ce 4+ extraction was achieved and the Ce to total rare earth ratio was upgraded to > 99%

Field Sampling Plan for the HWMA/RCRA Closure Certification of the TRA-731 Caustic and Acid Storage Tank System - 1997 Notice of Violation Consent Order

International Nuclear Information System (INIS)

Evans, S.K.

2002-01-01

This Field Sampling Plan for the HWMA/RCRA Closure Certification of the TRA-731 Caustic and Acid Storage Tank System is one of two documents that comprise the Sampling and Analysis Plan for the HWMA/RCRA closure certification of the TRA-731 caustic and acid storage tank system at the Idaho National Engineering and Environmental Laboratory. This plan, which provides information about sampling design, required analyses, and sample collection and handling procedures, is to be used in conjunction with the Quality Assurance Project Plan for the HWMA/RCRA Closure Certification of the TRA-731 Caustic and Acid Storage Tank System

Photon Differential Splatting for Rendering Caustics

DEFF Research Database (Denmark)

Frisvad, Jeppe Revall; Schjøth, Lars; Erleben, Kenny

2014-01-01

We present a photon splatting technique which reduces noise and blur in the rendering of caustics. Blurring of illumination edges is an inherent problem in photon splatting, as each photon is unaware of its neighbours when being splatted. This means that the splat size is usually based...... on heuristics rather than knowledge of the local flux density. We use photon differentials to determine the size and shape of the splats such that we achieve adaptive anisotropic flux density estimation in photon splatting. As compared to previous work that uses photon differentials, we present the first method...... where no photons or beams or differentials need to be stored in a map. We also present improvements in the theory of photon differentials, which give more accurate results and a faster implementation. Our technique has good potential for GPU acceleration, and we limit the number of parameters requiring...

Quality Assurance Project Plan for the HWMA/RCRA Closure Certification of the TRA-731 Caustic and Acid Storage Tank System - 1997 Notice of Violation Consent Order; TOPICAL

International Nuclear Information System (INIS)

Evans, S.K.

2002-01-01

This Quality Assurance Project Plan for the HWMA/RCRA Closure Certification of the TRA- 731 Caustic and Acid Storage Tank System is one of two documents that comprise the Sampling and Analysis Plan for the HWMA/RCRA closure certification of the TRA-731 caustic and acid storage tank system at the Idaho National Engineering and Environmental Laboratory. This plan, which provides information about the project description, project organization, and quality assurance and quality control procedures, is to be used in conjunction with the Field Sampling Plan for the HWMA/RCRA Closure Certification of the TRA-731 Caustic and Acid Storage Tank System. This Quality Assurance Project Plan specifies the procedures for obtaining the data of known quality required by the closure activities for the TRA-731 caustic and acid storage tank system

Characterizing low-mass binaries from observation of long-timescale caustic-crossing gravitational microlensing events

DEFF Research Database (Denmark)

Shin, I.-G; Han, C.; Choi, J.-Y

2012-01-01

solution by follow-up radial-velocity observation. For both events, the caustic-crossing parts of the light curves, which are critical for determining the physical lens parameters, were resolved by high-cadence survey observations and thus it is expected that the number of microlensing binaries...

Miscibility Evaluation Of The Next Generation Solvent With Polymers Currently Used At DWPF, MCU, And Saltstone

Energy Technology Data Exchange (ETDEWEB)

Fondeur, F. F.

2013-04-17

The Office of Waste Processing, within the Office of Technology Innovation and Development, funded the development of an enhanced Caustic-Side Solvent Extraction (CSSX) solvent for deployment at the Savannah River Site for removal of cesium from High Level Waste. This effort lead to the development of the Next Generation Solvent (NGS) with Tris (3,7-dimethyl octyl) guanidine (TiDG). The first deployment target for the NGS solvent is within the Modular CSSX Unit (MCU). Deployment of a new chemical within an existing facility requires verification that the new chemical components are compatible with the installed equipment. In the instance of a new organic solvent, the primary focus is on compatibility of the solvent with organic polymers used in the affected facility. This report provides the calculated data from exposing these polymers to the Next Generation Solvent. An assessment of the dimensional stability of polymers known to be used or present in the MCU, Defense Waste Processing Facility (DWPF), and Saltstone facilities that will be exposed to the NGS showed that TiDG could selectively affect the elastomers and some thermoplastics to varying extents, but the typical use of these polymers in a confined geometry will likely prevent the NGS from impacting component performance. The polymers identified as of primary concern include Grafoil® (flexible graphite), Tefzel®, Isolast®, ethylene-propylene-diene monomer (EPDM) rubber, nitrile-butadiene rubber (NBR), styrene-butadiene rubber (SBR), ultra high molecular weight polyethylene (UHMWPE), and fluorocarbon rubber (FKM). Certain polymers like NBR and EPDM were found to interact mildly with NGS but their calculated swelling and the confined geometry will impede interaction with NGS. In addition, it was found that Vellumoid (cellulose fibers-reinforced glycerin and protein) may leach protein and Polyvinyl Chloride (PVC) may leach plasticizer (such as Bis-Ethylhexyl-Phthalates) into the NGS solvent. Either case

H-Area Acid/Caustic Basin groundwater monitoring report. Second quarter 1994

International Nuclear Information System (INIS)

1994-09-01

During second quarter 1994, samples collected from the four HAC monitoring wells at the H-Area Acid/Caustic Basin received comprehensive analyses (exclusive of boron and lithium) and turbidity measurements. Monitoring results that exceeded the final Primary Drinking Water Standards (PDWS) or the Savannah River Site (SRS) flagging criteria or turbidity standard during the quarter are the focus of this report. Tritium exceeded the final PDWS in all four HAC wells during second quarter 1994. Carbon tetrachloride exceeded the final PDWS in well HAC 4. Aluminum exceeded its Flag 2 criterion in wells HAC 2, 3, and 4. Iron was elevated in wells HAC 1, 2, and 3. Manganese exceeded its Flag 2 criterion in well HAC 3. Specific conductance and total organic halogens were elevated in well HAC 2. No well samples exceeded the SRS turbidity standard. Groundwater flow direction in the water stable beneath the H-Area Acid/Caustic Basin was to the west during second quarter 1994. During previous quarters, the groundwater flow direction has been consistently to the northwest or the north-northwest. This apparent change in flow direction may be attributed to the lack of water elevations for wells HTF 16 and 17 and the anomalous water elevations for well HAC 2 during second quarter

The Role of Solvent Polarity on Low-Temperature Methanol Synthesis Catalyzed by Cu Nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Ahoba-Sam, Christian [Department of Process, Energy and Environmental Technology, University College of Southeast Norway, Porsgrunn (Norway); Olsbye, Unni [Department of Chemistry, University of Oslo, Oslo (Norway); Jens, Klaus-Joachim, E-mail: Klaus.J.Jens@usn.no [Department of Process, Energy and Environmental Technology, University College of Southeast Norway, Porsgrunn (Norway)

2017-07-14

Methanol syntheses at low temperature in a liquid medium present an opportunity for full syngas conversion per pass. The aim of this work was to study the role of solvents polarity on low-temperature methanol synthesis reaction using eight different aprotic polar solvents. A “once through” catalytic system, which is composed of Cu nanoparticles and sodium methoxide, was used for methanol synthesis at 100°C and 20 bar syngas pressure. Solvent polarity rather than the 7–10 nm Cu (and 30 nm Cu on SiO{sub 2}) catalyst used dictated trend of syngas conversion. Diglyme with a dielectric constant (ε) = 7.2 gave the highest syngas conversion among the eight different solvents used. Methanol formation decreased with either increasing or decreasing solvent ε value of diglyme (ε = 7.2). To probe the observed trend, possible side reactions of methyl formate (MF), the main intermediate in the process, were studied. MF was observed to undergo two main reactions; (i) decarbonylation to form CO and MeOH and (ii) a nucleophilic substitution to form dimethyl ether and sodium formate. Decreasing polarity favored the decarbonylation side reaction while increasing polarity favored the nucleophilic substitution reaction. In conclusion, our results show that moderate polarity solvents, e.g., diglyme, favor MF hydrogenolysis and, hence, methanol formation, by retarding the other two possible side reactions.

Caustic ring model of the Milky Way halo

International Nuclear Information System (INIS)

Duffy, L. D.; Sikivie, P.

2008-01-01

We present a proposal for the full phase-space distribution of the Milky Way halo. The model is axially and reflection symmetric and its time evolution is self-similar. It describes the halo as a set of discrete dark matter flows with stated densities and velocity vectors everywhere. We first discuss the general conditions under which the time evolution of a cold collisionless self-gravitating fluid is self-similar, and show that symmetry is not necessary for self-similarity. When spherical symmetry is imposed, the model is the same as described by Fillmore and Goldreich, and by Bertschinger, twenty-three years ago. The spherically symmetric model depends on one dimensionless parameter ε and two dimensionful parameters. We set ε=0.3, a value consistent with the slope of the power spectrum of density perturbations on galactic scales. The dimensionful parameters are determined by the galactic rotation velocity (220 km/s) at the position of the Sun and by the age of the Galaxy (13.7 Gyr). The properties of the outer caustics are derived in the spherically symmetric model. The structure of the inner halo depends on the angular momentum distribution of the dark matter particles. We assume that distribution to be axial and reflection symmetric, and dominated by net overall rotation. The inner caustics are rings whose radii are determined in terms of a single additional parameter j max . We summarize the observational evidence in support of the model. The evidence is consistent with j max =0.18 in Concordance cosmology, equivalent to j max,old =0.26 in Einstein-de Sitter cosmology. We give formulas to estimate the flow densities and velocity vectors anywhere in the Milky Way halo. The properties of the first 40 flows at the location of the Earth are listed.

A systematic fitting scheme for caustic-crossing microlensing events

DEFF Research Database (Denmark)

Kains ...[et al], N.; Jørgensen, Uffe Gråe

2009-01-01

with a source crossing the whole caustic structure in less than three days. In order to identify all possible models we conduct an extensive search of the parameter space, followed by a refinement of the parameters with a Markov Chain Monte Carlo algorithm. We find a number of low-chi(2) regions...... in the parameter space, which lead to several distinct competitive best models. We examine the parameters for each of them, and estimate their physical properties. We find that our fitting strategy locates several minima that are difficult to find with other modelling strategies and is therefore a more appropriate...

Purification and decontamination of a caustic water by reverse osmosis

International Nuclear Information System (INIS)

Plock, C.E.; Travis, T.N.

1981-01-01

A reverse osmosis pilot plant was used to decontaminate a caustic water containing low concentrations of uranium, plutonium, and americium. The concentrations of the plutonium and americium were less than one picocurie per liter in the product water. The concentrations of the uranium was reduced to 4.4 picocuries per liter in the product water, which is a reduction of greater than 99%. The reverse osmosis pilot plant was operated at a 98% water recovery, which produced 25,000 gallons per day of product water

Temperature Induced Solubility Transitions of Various Poly(2-oxazolines in Ethanol-Water Solvent Mixtures

Directory of Open Access Journals (Sweden)

Hanneke M. L. Lambermont-Thijs

2010-08-01

Full Text Available The solution behavior of a series of poly(2-oxazolines with different side chains, namely methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, pentyl, hexyl, heptyl, octyl, nonyl, phenyl and benzyl, are reported in ethanol-water solvent mixtures based on turbidimetry investigations. The LCST transitions of poly(2-oxazolines with propyl side chains and the UCST transitions of the poly(2-oxazolines with more hydrophobic side chains are discussed in relation to the ethanol-water solvent composition and structure. The poly(2-alkyl-2-oxazolines with side chains longer than propyl only dissolved during the first heating run, which is discussed and correlated to the melting transition of the polymers.

Using tank 107-AN caustic addition for confirmation of mixing scale relationship

International Nuclear Information System (INIS)

Chang, S.C.

1995-05-01

A subscale jet mixing program was carried out in two scale tanks to extend the basis of previous subscale tests to include in-tank geometry associated with tank AN-107. The laboratory data will be correlated with the data to be collected in the upcoming tank AN-107 mixing and caustic addition test. The objective is to verify the scaling relationship used in the MWTF mixer design

Results From The Salt Disposition Project Next Generation Solvent Demonstration Plan

Energy Technology Data Exchange (ETDEWEB)

Peters, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Fondeur, F. F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Taylor-Pashow, K. M.L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2014-04-02

Strip Effluent Hold Tank (SEHT), Decontaminated Salt Solution Hold Tank (DSSHT), Caustic Wash Tank (CWT) and Solvent Hold Tank (SHT) samples were taken throughout the Next Generation Solvent (NGS) Demonstration Plan. These samples were analyzed and the results are reported. SHT: The solvent behaved as expected, with no bulk changes in the composition over time, with the exception of the TOA and TiDG. The TiDG depletion is higher than expected, and consideration must be taken on the required rate of replenishment. Monthly sampling of the SHT is warranted. If possible, additional SHT samples for TiDG analysis (only) would help SRNL refine the TiDG degradation model. CWT: The CWT samples show the expected behavior in terms of bulk chemistry. The 137Cs deposited into the CWT varies somewhat, but generally appears to be lower than during operations with the BOBCalix solvent. While a few minor organic components were noted to be present in the Preliminary sample, at this time these are thought to be artifacts of the sample preparation or may be due to the preceding solvent superwash. DSSHT: The DSSHT samples show the predicted bulk chemistry, although they point towards significant dilution at the front end of the Demonstration. The 137Cs levels in the DSSHT are much lower than during the BOBCalix operations, which is the expected observation. SEHT: The SEHT samples represent the most different output of all four of the outputs from MCU. While the bulk chemistry is as expected, something is causing the pH of the SEHT to be higher than what would be predicted from a pure stream of 0.01 M boric acid. There are several possible different reasons for this, and SRNL is in the process of investigating. Other than the pH issue, the SEHT is as predicted. In summary, the NGS Demonstration Plan samples indicate that the MCU system, with the Blend Solvent, is operating as expected. The only issue of concern regards the pH of the SEHT, and SRNL is in the process of investigating

A comparative study between the use of artificial neural networks and multiple linear regression for caustic concentration prediction in a stage of alumina production

Directory of Open Access Journals (Sweden)

Giovanni Leopoldo Rozza

2015-09-01

Full Text Available With world becoming each day a global village, enterprises continuously seek to optimize their internal processes to hold or improve their competitiveness and make better use of natural resources. In this context, decision support tools are an underlying requirement. Such tools are helpful on predicting operational issues, avoiding cost risings, loss of productivity, work-related accident leaves or environmental disasters. This paper has its focus on the prediction of spent liquor caustic concentration of Bayer process for alumina production. Caustic concentration measuring is essential to keep it at expected levels, otherwise quality issues might arise. The organization requests caustic concentration by chemical analysis laboratory once a day, such information is not enough to issue preventive actions to handle process inefficiencies that will be known only after new measurement on the next day. Thereby, this paper proposes using Multiple Linear Regression and Artificial Neural Networks techniques a mathematical model to predict the spent liquor´s caustic concentration. Hence preventive actions will occur in real time. Such models were built using software tool for numerical computation (MATLAB and a statistical analysis software package (SPSS. The models output (predicted caustic concentration were compared with the real lab data. We found evidence suggesting superior results with use of Artificial Neural Networks over Multiple Linear Regression model. The results demonstrate that replacing laboratorial analysis by the forecasting model to support technical staff on decision making could be feasible.

Determination of the impact of glycolate on ARP and MCU operations

Energy Technology Data Exchange (ETDEWEB)

Taylor-Pashow, K. M.L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Peters, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Fondeur, F. F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Shehee, T. C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Washington, A. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-05-17

Savannah River Remediation (SRR) is evaluating an alternate flowsheet for the Defense Waste Processing Facility (DWPF) using glycolic acid as a reductant. An important aspect of the development of the glycolic acid flowsheet is determining if glycolate has any detrimental downstream impacts. Testing was performed to determine if there is any impact to the strontium and actinide sorption by monosodium titanate (MST) and modified monosodium titanate (mMST) or if there is an impact to the cesium removal, phase separation, or coalescer performance at the Modular Caustic-Side Solvent Extraction Processing Unit (MCU).

SALTSTONE VAULT CLASSIFICATION SAMPLES MODULAR CAUSTIC SIDE SOLVENT EXTRACTION UNIT/ACTINIDE REMOVAL PROCESS WASTE STREAM APRIL 2011

Energy Technology Data Exchange (ETDEWEB)

Eibling, R.

2011-09-28

Savannah River National Laboratory (SRNL) was asked to prepare saltstone from samples of Tank 50H obtained by SRNL on April 5, 2011 (Tank 50H sampling occurred on April 4, 2011) during 2QCY11 to determine the non-hazardous nature of the grout and for additional vault classification analyses. The samples were cured and shipped to Babcock & Wilcox Technical Services Group-Radioisotope and Analytical Chemistry Laboratory (B&W TSG-RACL) to perform the Toxic Characteristic Leaching Procedure (TCLP) and subsequent extract analysis on saltstone samples for the analytes required for the quarterly analysis saltstone sample. In addition to the eight toxic metals - arsenic, barium, cadmium, chromium, mercury, lead, selenium and silver - analytes included the underlying hazardous constituents (UHC) antimony, beryllium, nickel, and thallium which could not be eliminated from analysis by process knowledge. Additional inorganic species determined by B&W TSG-RACL include aluminum, boron, chloride, cobalt, copper, fluoride, iron, lithium, manganese, molybdenum, nitrate/nitrite as Nitrogen, strontium, sulfate, uranium, and zinc and the following radionuclides: gross alpha, gross beta/gamma, 3H, 60Co, 90Sr, 99Tc, 106Ru, 106Rh, 125Sb, 137Cs, 137mBa, 154Eu, 238Pu, 239/240Pu, 241Pu, 241Am, 242Cm, and 243/244Cm. B&W TSG-RACL provided subsamples to GEL Laboratories, LLC for analysis for the VOCs benzene, toluene, and 1-butanol. GEL also determines phenol (total) and the following radionuclides: 147Pm, 226Ra and 228Ra. Preparation of the 2QCY11 saltstone samples for the quarterly analysis and for vault classification purposes and the subsequent TCLP analyses of these samples showed that: (1) The saltstone waste form disposed of in the Saltstone Disposal Facility in 2QCY11 was not characteristically hazardous for toxicity. (2) The concentrations of the eight RCRA metals and UHCs identified as possible in the saltstone waste form were present at levels below the UTS. (3) Most of the inorganic species measured in the leachate do not exceed the MCL, SMCL or TW limits. (4) The inorganic waste species that exceeded the MCL by more than a factor of 10 were nitrate, nitrite and the sum of nitrate and nitrite. (5) Analyses met all quality assurance specifications of US EPA SW-846. (6) The organic species (benzene, toluene, 1-butanol, phenol) were either not detected or were less than reportable for the vault classification samples. (7) The gross alpha and radium isotopes could not be determined to the MCL because of the elevated background which raised the detection limits. (8) Most of the beta/gamma activity was from 137Cs and its daughter 137mBa. (9) The concentration of 137Cs and 90Sr were present in the leachate at concentrations 1/40th and 1/8th respectively than in the 2003 vault classification samples. The saltstone waste form placed in the Saltstone Disposal Facility in 2QCY11 met the SCHWMR R.61-79.261.24(b) RCRA metals requirements for a nonhazardous waste form. The TCLP leachate concentrations for nitrate, nitrite and the sum of nitrate and nitrite were greater than 10x the MCLs in SCDHEC Regulations R.61-107.19, Part I A, which confirms the Saltstone Disposal Facility classification as a Class 3 Landfill. The saltstone waste form placed in the Saltstone Disposal Facility in 2QCY11 met the R.61-79.268.48(a) non wastewater treatment standards.

Influence of Solvent-Solvent and Solute-Solvent Interaction Properties on Solvent-Mediated Potential

International Nuclear Information System (INIS)

Zhou Shiqi

2005-01-01

A recently proposed universal calculational recipe for solvent-mediated potential is applied to calculate excess potential of mean force between two large Lennard-Jones (LJ) or hard core attractive Yukawa particles immersed in small LJ solvent bath at supercritical state. Comparison between the present prediction with a hypernetted chain approximation adopted for solute-solute correlation at infinitely dilute limit and existing simulation data shows high accuracy for the region with large separation, and qualitative reliability for the solute particle contact region. The calculational simplicity of the present recipe allows for a detailed investigation on the effect of the solute-solvent and solvent-solvent interaction details on the excess potential of mean force. The resultant conclusion is that gathering of solvent particles near a solute particle leads to repulsive excess PMF, while depletion of solvent particles away from the solute particle leads to attractive excess PMF, and minor change of the solvent-solvent interaction range has large influence on the excess PMF.

The Variation of Interface Formation with Slurry Viscosity Change in Side-By-Side Tape Casting

DEFF Research Database (Denmark)

Bulatova, Regina; Jabbari, Masoud; Andersen, Kjeld Bøhm

Homogenous and flexible adjacently graded tapes were produced by casting the organic-based slurries simultaneously. To develop side-by-side tape casing (SBSTC), the material optimization, modernization of the doctor blade design, and parameters control of such processes as casting, drying, de......-bindering and sintering were studied. Solvent and binder concentrations were varied in order to optimize co-casting flow, as well as the drying and sintering shrinkage. Tapes were evaluated in terms of rheological behavior of the slurries, the green and sintered tape microstructure, the quality of the interface area...

Direct anodic hydrochloric acid and cathodic caustic production during water electrolysis

Science.gov (United States)

Lin, Hui-Wen; Cejudo-Marín, Rocío; Jeremiasse, Adriaan W.; Rabaey, Korneel; Yuan, Zhiguo; Pikaar, Ilje

2016-02-01

Hydrochloric acid (HCl) and caustic (NaOH) are among the most widely used chemicals by the water industry. Direct anodic electrochemical HCl production by water electrolysis has not been successful as current commercially available electrodes are prone to chlorine formation. This study presents an innovative technology simultaneously generating HCl and NaOH from NaCl using a Mn0.84Mo0.16O2.23 oxygen evolution electrode during water electrolysis. The results showed that protons could be anodically generated at a high Coulombic efficiency (i.e. ≥ 95%) with chlorine formation accounting for 3 ~ 5% of the charge supplied. HCl was anodically produced at moderate strengths at a CE of 65 ± 4% together with a CE of 89 ± 1% for cathodic caustic production. The reduction in CE for HCl generation was caused by proton cross-over from the anode to the middle compartment. Overall, this study showed the potential of simultaneous HCl and NaOH generation from NaCl and represents a major step forward for the water industry towards on-site production of HCl and NaOH. In this study, artificial brine was used as a source of sodium and chloride ions. In theory, artificial brine could be replaced by saline waste streams such as Reverse Osmosis Concentrate (ROC), turning ROC into a valuable resource.

Mass Transfer And Hydraulic Testing Of The V-05 And V-10 Contactors With The Next Generation Solvent

Energy Technology Data Exchange (ETDEWEB)

Herman, D. T.; Duignan, M. R.; Williams, M. R.; Peters, T. B.; Poirier, M. R.; Fondeur, F. F.

2013-07-31

The Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) facility is actively pursuing the transition from the current BOBCalixC6 based solvent to the Next Generation Solvent (NGS)-MCU solvent. To support this integration of NGS into the MCU facilities, Savannah River Remediation (SRR) requested that Savannah River National Laboratory (SRNL) perform testing of a blend of the NGS (MaxCalix based solvent) with the current solvent (BOBCalixC6 based solvent) for the removal of cesium (Cs) from the liquid salt waste stream. This testing differs from prior testing by utilizing a blend of BOBCalixC6 based solvent and the NGS with the full (0.05 M) concentration of the MaxCalix as well as a new suppressor, tris(3,7dimethyloctyl) guanidine. Single stage tests were conducted using the full size V-05 and V-10 centrifugal contactors installed at SRNL. These tests were designed to determine the mass transfer and hydraulic characteristics with the NGS solvent blended with the projected heel of the BOBCalixC6 based solvent that will exist in MCU at time of transition. The test program evaluated the amount of organic carryover and the droplet size of the organic carryover phases using several analytical methods. Stage efficiency and mass distribution ratios were determined by measuring Cs concentration in the aqueous and organic phases during single contactor testing. The nominal cesium distribution ratio, D(Cs) measured for extraction ranged from 37-60. The data showed greater than 96% stage efficiency for extraction. No significant differences were noted for operations at 4, 8 or 12 gpm aqueous salt simulant feed flow rates. The first scrub test (contact with weak caustic solution) yielded average scrub D(Cs) values of 3.3 to 5.2 and the second scrub test produced an average value of 1.8 to 2.3. For stripping behavior, the “first stage” D Cs) values ranged from 0.04 to 0.08. The efficiency of the low flow (0.27 gpm aqueous) was calculated to be 82.7%. The Spreadsheet

Development of a novel solvent for the simultaneous separation of strontium and cesium from dissolved Spent Nuclear Fuel solutions

International Nuclear Information System (INIS)

Catherine L. Riddle; John D. Baker; Jack D. Law; Christopher A. McGrath; David H. Meikrantz; Bruce J. Mincher; Dean R. Peterman; Terry A. Todd

2004-01-01

The recovery of Cs and Sr from acidic solutions by solvent extraction has been investigated. The goal of this project was to develop an extraction process to remove Cs and Sr from high-level waste in an effort to reduce the heat loading in storage. Solvents for the extraction of Cs and Sr separately have been used on both caustic and acidic spent nuclear fuel waste in the past. The objective of this research was to find a suitable solvent for the extraction of both Cs and Sr simultaneously from acidic nitrate media. The solvents selected for this research possess good stability and extraction behavior when mixed together. The extraction experiments were performed with 4,4,(5)-Di-(tbutyldicyclohexano)-18-crown-6 (DtBuCH18C6), Calix[4]arene-bis-(tert-octylbenzocrown-6) (BOBCalixC6) and 1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol (Cs-7SB modifier) in a branched aliphatic kerosene (Isopar L). The BOBCalixC6 and Cs-7SB modifier were developed at Oak Ridge National Laboratory (ORNL) by Bonnesen et al. [1]. The values obtained from the SREX solvent for DSr in 1 M nitric acid ranged from 0.7 to 2.2 at 25 C and 10 C respectively. The values for DCs in 1 M nitric acid with the CSSX solvent ranged from 8.0 to 46.0 at 25 C and 10 C respectively. A new mixed solvent, developed at the Idaho National Engineering and Environmental Laboratory (INEEL) by Riddle et al. [2], showed distributions for Sr ranging from 8.8 to 17.4 in 1 M nitric acid at 25 C and 10 C respectively. The DCs for the mixed solvent ranged from 7.7 to 20.2 in 1 M nitric acid at 25 C to 10 C respectively. The unexpectedly high distributions for Sr at both 25 C and 10 C show a synergy in the mixed solvent. The DCs, although lower than with CSSX solvent, still showed good extraction behavior

Biodiesel production from ethanolysis of palm oil using deep eutectic solvent (DES) as co-solvent

Science.gov (United States)

Manurung, R.; Winarta, A.; Taslim; Indra, L.

2017-06-01

Biodiesel produced from ethanolysis is more renewable and have better properties (higher oxidation stability, lower cloud and pour point) compared to methanolysis, but it has a disadvantage such as complicated purification. To improve ethanolysis process, deep eutectic solvent (DES) can be prepared from choline chloride and glycerol and used as co-solvent in ethanolysis. The deep eutectic solvent is formed from a quaternary ammonium salt (choline chloride) and a hydrogen bond donor (Glycerol), it is a non-toxic, biodegradable solvent compared to a conventional volatile organic solvent such as hexane. The deep eutectic solvent is prepared by mixing choline chloride and glycerol with molar ratio 1:2 at temperature 80 °C, stirring speed 300 rpm for 1 hour. The DES is characterized by its density and viscosity. The ethanolysis is performed at a reaction temperature of 70 °C, ethanol to oil molar ratio of 9:1, potassium hydroxide as catalyst concentration of 1.2 wt. DES as co-solvent with concentration 0.5 to 3 wt. stirring speed 400 rpm, and a reaction time 1 hour. The obtained biodiesel is then characterized by its density, viscosity, and ester content. The oil - ethanol phase condition is observed in the reaction tube. The oil - ethanol phase with DES tends to form meniscus compared to without DES, showed that oil and ethanol become more slightly miscible, which favors the reaction. Using DES as co-solvent in ethanolysis showed increasing in yield and easier purification. The esters properties meet the international standards ASTM D6751, with the highest yield achieved 83,67 with 99,77 conversion at DES concentration 2 . Increasing DES concentration above 2 in ethanolysis decrease the conversion and yield, because of the excessive glycerol in the systems makes the reaction equilibrium moves to the reactant side.

Cost benefit of caustic recycle for tank waste remediation at the Hanford and Savannah River Sites

International Nuclear Information System (INIS)

DeMuth, S.

1998-01-01

The potential cost savings due to the use of caustic recycle used in conjunction with remediation of radioactive underground storage tank waste, is shown in a figure for the Hanford and Savannah River sites. Two cost savings estimates for each case have been made for Hanford, and one cost savings estimate for each case have been made for Hanford, and one cost savings estimate for each case has been made for the Savannah River site. This is due to the Hanford site remediation effort being less mature than that of Savannah River; and consequently, a range of cost savings being more appropriate for Hanford. This range of cost savings (rather than a ingle value) for each case at Hanford is due to cost uncertainties related to the LAW immobilization operation. Caustic recycle Case-1 has been defined as the sodium required to meet al identified caustic needs for the entire Site. Case-2 has been defined as the maximum sodium which can be separated from the low activity waste without precipitation of Al(OH) 3 . It has been determined that the potential cost savings at Hanford ranges from $194 M to $215 M for Case-1, and $293 M to $324 M for Case-2. The potential cost savings at Savannah River are $186 M for Case-1 and $281 M for Case-2. A discussion of the uncertainty associated with these cost savings estimates can be found in the Discussion and Conclusions section

Evaluation of the Hydraulic Performance and Mass Transfer Efficiency of the CSSX Process with the Optimized Solvent in a Single Stage of 5.5-Cm Diameter Centrifugal Contactor

International Nuclear Information System (INIS)

Law, J.D.; Tillotson, R.D.; Todd, T.A.

2002-01-01

The Caustic-Side Solvent Extraction (CSSX) process has been selected for the separation of cesium from Savannah River Site high-level waste. The solvent composition used in the CSSX process was recently optimized so that the solvent is no longer supersaturated with respect to the calixarene crown ether extractant. Hydraulic performance and mass transfer efficiency testing of a single stage of 5.5-cm ORNL-designed centrifugal contactor has been performed for the CSSX process with the optimized solvent. Maximum throughputs of the 5.5-cm centrifugal contactor, as a function of contactor rotor speed, have been measured for the extraction, scrub, strip, and wash sections of the CSSX flowsheet at the baseline organic/aqueous flow ratios (O/A) of the process, as well as at O/A's 20% higher and 20% lower than the baseline. Maximum throughputs are comparable to the design throughput of the contactor, as well as with throughputs obtained previously in a 5-cm centrifugal contactor with the non-optimized CSSX solvent formulation. The 20% variation in O/A had minimal effect on contactor throughput. Additionally, mass transfer efficiencies have been determined for the extraction and strip sections of the flowsheet. Efficiencies were lower than the process goal of greater than or equal to 80%, ranging from 72 to 75% for the extraction section and from 36 to 60% in the strip section. Increasing the mixing intensity and/or the solution level in the mixing zone of the centrifugal contactor (residence time) could potentially increase efficiencies. Several methods are available to accomplish this including (1) increasing the size of the opening in the bottom of the rotor, resulting in a contactor which is partially pumping instead of fully pumping, (2) decreasing the number of vanes in the contactor, (3) increasing the vane height, or (4) adding vanes on the rotor and baffles on the housing of the contactor. The low efficiency results obtained stress the importance of proper design of

The effect of concentration on the structure and crystallinity of a cementitious waste form for caustic wastes

International Nuclear Information System (INIS)

Chung, Chul-Woo; Turo, Laura A.; Ryan, Joseph V.; Johnson, Bradley R.; McCloy, John S.

2013-01-01

Highlights: ► Cast Stone: Portland cement, fly ash, blast furnace slag, and simulated nuclear waste. ► Caustic secondary waste from the off-gas of a vitrification process was targeted. ► Crystallinity, micro- and mesostructure, and engineering properties characterized. ► Waste concentration varied from 0 to 2.5 M, but caused minimal changes. ► Cast Stone shows good compositional versatility as a secondary waste form. -- Abstract: Cement-based waste forms have long been considered economical technologies for disposal of various types of waste. A solidified cementitious waste form, Cast Stone, has been identified to immobilize the radioactive secondary waste from vitrification processes. In this work, Cast Stone was considered for a Na-based caustic liquid waste, and its physical properties were analyzed as a function of liquid waste loading up to 2 M Na. Differences in crystallinity (phase composition), microstructure, mesostructure (pore size distribution and surface area), and macrostructure (density and compressive strength) were investigated using various analytical techniques, in order to assess the suitability of Cast Stone as a chemically durable waste. It was found that the concentration of secondary waste simulant (caustic waste) had little effect on the relevant engineering properties of Cast Stone, showing that Cast Stone could be an effective and tolerant waste form for a wide range of concentrations of high sodium waste

On the Observability of Individual Population III Stars and Their Stellar-mass Black Hole Accretion Disks through Cluster Caustic Transits

Science.gov (United States)

Windhorst, Rogier A.; Timmes, F. X.; Wyithe, J. Stuart B.; Alpaslan, Mehmet; Andrews, Stephen K.; Coe, Daniel; Diego, Jose M.; Dijkstra, Mark; Driver, Simon P.; Kelly, Patrick L.; Kim, Duho

2018-02-01

We summarize panchromatic Extragalactic Background Light data to place upper limits on the integrated near-infrared surface brightness (SB) that may come from Population III stars and possible accretion disks around their stellar-mass black holes (BHs) in the epoch of First Light, broadly taken from z ≃ 7–17. Theoretical predictions and recent near-infrared power spectra provide tighter constraints on their sky signal. We outline the physical properties of zero-metallicity Population III stars from MESA stellar evolution models through helium depletion and of BH accretion disks at z≳ 7. We assume that second-generation non-zero-metallicity stars can form at higher multiplicity, so that BH accretion disks may be fed by Roche-lobe overflow from lower-mass companions. We use these near-infrared SB constraints to calculate the number of caustic transits behind lensing clusters that the James Webb Space Telescope and the next-generation ground-based telescopes may observe for both Population III stars and their BH accretion disks. Typical caustic magnifications can be μ ≃ {10}4{--}{10}5, with rise times of hours and decline times of ≲ 1 year for cluster transverse velocities of {v}T≲ 1000 km s‑1. Microlensing by intracluster-medium objects can modify transit magnifications but lengthen visibility times. Depending on BH masses, accretion-disk radii, and feeding efficiencies, stellar-mass BH accretion-disk caustic transits could outnumber those from Population III stars. To observe Population III caustic transits directly may require monitoring 3–30 lensing clusters to {AB}≲ 29 mag over a decade.

The impact of the MCU life extension solvent on sludge batch 8 projected operating windows

International Nuclear Information System (INIS)

Peeler, D.K.; Edwards, T.B.

2013-01-01

As a part of the Actinide Removal Process (ARP)/Modular Caustic Side Solvent Extraction Unit (MCU) Life Extension Project, a next generation solvent (NGS) and a new strip acid will be deployed. The strip acid will be changed from dilute nitric acid to dilute boric acid (0.01 M). Because of these changes, experimental testing or evaluations with the next generation solvent are required to determine the impact of these changes (if any) to Chemical Process Cell (CPC) activities, glass formulation strategies, and melter operations at the Defense Waste Processing Facility (DWPF). The introduction of the dilute (0.01 M) boric acid stream into the DWPF flowsheet has a potential impact on glass formulation and frit development efforts since B203 is a major oxide in frits developed for DWPF. Prior knowledge of this stream can be accounted for during frit development efforts but that was not the case for Sludge Batch 8 (SB8). Frit 803 has already been recommended and procured for SB8 processing; altering the frit to account for the incoming boron from the strip effluent (SE) is not an option for SB8. Therefore, the operational robustness of Frit 803 to the introduction of SE including its compositional tolerances (i.e., up to 0.0125M boric acid) is of interest and was the focus of this study. The primary question to be addressed in the current study was: What is the impact (if any) on the projected operating windows for the Frit 803 - SB8 flowsheet to additions of B203 from the SE in the Sludge Receipt and Adjustment Tank (SRAT)? More specifically, will Frit 803 be robust to the potential compositional changes occurring in the SRAT due to sludge variation, varying additions of ARP and/or the introduction of SE by providing access to waste loadings (WLs) of interest to DWPF? The Measurement Acceptability Region (MAR) results indicate there is very little, if any, impact on the projected operating windows for the Frit 803 - SB8 system regardless of the presence or absence of

27 CFR 21.63 - Formula No. 36.

Science.gov (United States)

2010-04-01

... pounds of caustic soda, liquid grade, containing 50 percent sodium hydroxide by weight; or 12.0 pounds of caustic soda, liquid grade, containing 73 percent sodium hydroxide by weight. (b) Authorized uses. (1) As a solvent: 141.Shampoos. 142.Soap and bath preparations. 210.External pharmaceuticals, not U.S.P. or...

Mass Transfer And Hydraulic Testing Of The V-05 And V-10 Contactors With The Next Generation Solvent

International Nuclear Information System (INIS)

Herman, D. T.; Duignan, M. R.; Williams, M. R.; Peters, T. B.; Poirier, M. R.; Fondeur, F. F.

2013-01-01

The Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) facility is actively pursuing the transition from the current BOBCalixC6 based solvent to the Next Generation Solvent (NGS)-MCU solvent. To support this integration of NGS into the MCU facilities, Savannah River Remediation (SRR) requested that Savannah River National Laboratory (SRNL) perform testing of a blend of the NGS (MaxCalix based solvent) with the current solvent (BOBCalixC6 based solvent) for the removal of cesium (Cs) from the liquid salt waste stream. This testing differs from prior testing by utilizing a blend of BOBCalixC6 based solvent and the NGS with the full (0.05 M) concentration of the MaxCalix as well as a new suppressor, tris(3,7 dimethyloctyl) guanidine. Single stage tests were conducted using the full size V-05 and V-10 centrifugal contactors installed at SRNL. These tests were designed to determine the mass transfer and hydraulic characteristics with the NGS solvent blended with the projected heel of the BOBCalixC6 based solvent that will exist in MCU at time of transition. The test program evaluated the amount of organic carryover and the droplet size of the organic carryover phases using several analytical methods. Stage efficiency and mass distribution ratios were determined by measuring Cs concentration in the aqueous and organic phases during single contactor testing. The nominal cesium distribution ratio, D(Cs) measured for extraction ranged from 37-60. The data showed greater than 96% stage efficiency for extraction. No significant differences were noted for operations at 4, 8 or 12 gpm aqueous salt simulant feed flow rates. The first scrub test (contact with weak caustic solution) yielded average scrub D(Cs) values of 3.3 to 5.2 and the second scrub test produced an average value of 1.8 to 2.3. For stripping behavior, the ''first stage'' D Cs) values ranged from 0.04 to 0.08. The efficiency of the low flow (0.27 gpm aqueous) was calculated to be 82.7%. The Spreadsheet

Extraction, -scrub, -strip test results from the interim salt disposition program macrobatch 10 tank 21H qualification samples

Energy Technology Data Exchange (ETDEWEB)

Peters, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-06-26

Savannah River National Laboratory (SRNL) analyzed samples from Tank 21H in support of qualification of Macrobatch (Salt Batch) 10 for the Interim Salt Disposition Program (ISDP). The Salt Batch 10 characterization results were previously reported.ii,iii An Extraction, -Scrub, -Strip (ESS) test was performed to determine cesium distribution ratios (D(Cs)) and cesium concentration in the strip effluent (SE) and decontaminated salt solution (DSS) streams; this data will be used by Tank Farm Engineering to project a cesium decontamination factor (DF). This test used actual Tank 21H material, and a sample of the NGS Blend solvent currently being used at the Modular Caustic-Side Solvent Extraction Unit (MCU). The ESS test showed acceptable performance with an extraction D(Cs) value of 110. This value is consistent with results from previous salt batch ESS tests using similar solvent formulations. This is better than the predicted value of 39.8 from a recently created D(Cs) model.

AMDTreat 5.0+ with PHREEQC titration module to compute caustic chemical quantity, effluent quality, and sludge volume

Science.gov (United States)

Cravotta, Charles A.; Means, Brent P; Arthur, Willam; McKenzie, Robert M; Parkhurst, David L.

2015-01-01

Alkaline chemicals are commonly added to discharges from coal mines to increase pH and decrease concentrations of acidity and dissolved aluminum, iron, manganese, and associated metals. The annual cost of chemical treatment depends on the type and quantities of chemicals added and sludge produced. The AMDTreat computer program, initially developed in 2003, is widely used to compute such costs on the basis of the user-specified flow rate and water quality data for the untreated AMD. Although AMDTreat can use results of empirical titration of net-acidic or net-alkaline effluent with caustic chemicals to accurately estimate costs for treatment, such empirical data are rarely available. A titration simulation module using the geochemical program PHREEQC has been incorporated with AMDTreat 5.0+ to improve the capability of AMDTreat to estimate: (1) the quantity and cost of caustic chemicals to attain a target pH, (2) the chemical composition of the treated effluent, and (3) the volume of sludge produced by the treatment. The simulated titration results for selected caustic chemicals (NaOH, CaO, Ca(OH)2, Na2CO3, or NH3) without aeration or with pre-aeration can be compared with or used in place of empirical titration data to estimate chemical quantities, treated effluent composition, sludge volume (precipitated metals plus unreacted chemical), and associated treatment costs. This paper describes the development, evaluation, and potential utilization of the PHREEQC titration module with the new AMDTreat 5.0+ computer program available at http://www.amd.osmre.gov/.

Effect of competing ions and causticization on the ammonia adsorption by a novel poly ligand exchanger (PLE) ammonia adsorption reagent.

Science.gov (United States)

Chen, Quanzhou; Zhou, Kanggen; Hu, Yuanjuan; Liu, Fang; Wang, Aihe

2017-03-01

In this paper, a poly ligand exchanger, Cu(II)-loaded chelating resin named ammonia adsorption reagent (AMAR), bearing the functional group of weak iminodiacetate acid, was prepared to efficiently remove ammonia from solutions. Batch adsorption equilibrium experiments were conducted under a range of conditions. The effects of pH on the removal of ammonia by AMAR were investigated at 25 °C. The copper loaded on the resin forms a complex with NH 3 in solution under alkaline condition. The effect of alkaline dosage (AD) on the ammonia adsorption was investigated. The maximum breakthrough bed volumes were obtained when the AD was set as 0.75 mmol OH - /mL. The higher AD did not guarantee the better ammonia removal efficiency due to the forming of Cu(OH) 2 precipitate between OH - in solutions and Cu(II) on the resin. The effect of competing ions on the adsorption breakthrough curve of virgin AMAR and causticized AMAR was also investigated. The results demonstrated that the existence of competing ions had a negative impact on the adsorption capacity for both virgin AMAR and causticized AMAR. After causticization, the AMAR was more resistant to the competing ions comparing with virgin AMAR. The bivalent Ca 2+ affects the ammonia adsorption more than does the monovalent Na + .

Electrochemical studies on stress corrosion cracking of incoloy-800 in caustic solution. Part II: Precracking samples

Directory of Open Access Journals (Sweden)

Dinu Alice

2006-01-01

Full Text Available Stress corrosion cracking (SCC in a caustic medium may affect the secondary circuit tubing of a CANDU NPP cooled with river water, due to an accidental formation of a concentrated alkaline environment in the areas with restricted circulation, as a result of a leakage of cooling water from the condenser. To evaluate the susceptibility of Incoloy-800 (used to manufacture steam generator tubes for CANDU NPP to SCC, some accelerated corrosion tests were conducted in an alkaline solution (10% NaOH, pH = 13. These experiments were performed at ambient temperature and 85 °C. We used the potentiodynamic method and the potentiostatic method, simultaneously monitoring the variation of the open circuit potential during a time period (E corr/time curve. The C-ring method was used to stress the samples. In order to create stress concentrations, mechanical precracks with a depth of 100 or 250 μm were made on the outer side of the C-rings. Experimental results showed that the stressed samples were more susceptible to SCC than the unstressed samples whereas the increase in temperature and crack depth lead to an increase in SCC susceptibility. Incipient micro cracks of a depth of 30 μm were detected in the area of the highest peak of the mechanical precrack.

Driven polymer translocation in good and bad solvent: Effects of hydrodynamics and tension propagation.

Science.gov (United States)

Moisio, J E; Piili, J; Linna, R P

2016-08-01

We investigate the driven polymer translocation through a nanometer-scale pore in the presence and absence of hydrodynamics both in good and bad solvent. We present our results on tension propagating along the polymer segment on the cis side that is measured for the first time using our method that works also in the presence of hydrodynamics. For simulations we use stochastic rotation dynamics, also called multiparticle collision dynamics. We find that in the good solvent the tension propagates very similarly whether hydrodynamics is included or not. Only the tensed segment is by a constant factor shorter in the presence of hydrodynamics. The shorter tensed segment and the hydrodynamic interactions contribute to a smaller friction for the translocating polymer when hydrodynamics is included, which shows as smaller waiting times and a smaller exponent in the scaling of the translocation time with the polymer length. In the bad solvent hydrodynamics has a minimal effect on polymer translocation, in contrast to the good solvent, where it speeds up translocation. We find that under bad-solvent conditions tension does not spread appreciably along the polymer. Consequently, translocation time does not scale with the polymer length. By measuring the effective friction in a setup where a polymer in free solvent is pulled by a constant force at the end, we find that hydrodynamics does speed up collective polymer motion in the bad solvent even more effectively than in the good solvent. However, hydrodynamics has a negligible effect on the motion of individual monomers within the highly correlated globular conformation on the cis side and hence on the entire driven translocation under bad-solvent conditions.

Prediction of complications following unintentional caustic ingestion in children. Is endoscopy always necessary?

DEFF Research Database (Denmark)

Christesen, H B

1995-01-01

The records of 115 children hospitalized following caustic ingestion over an 18.5-year period from 1976 to 1994 were reviewed. The relationship between types of product ingested, signs and symptoms, degree of esophageal injury and complications was analyzed. All complications were the result...... of strong alkali ingestion (sensitivity = 1.0). Among the 102 incident patients, 36.8% of lye ingestions resulted in complications, whereas only 2.7% (one) of automatic dishwasher detergent (ADD) ingestions caused any complications (p

H-Area Acid/Caustic Basin Groundwater Monitoring Report

International Nuclear Information System (INIS)

Thompson, C.Y.

1993-03-01

During fourth quarter 1992, samples from the four HAC monitoring wells at the H-Area Acid/Caustic Basin received comprehensive analyses. Monitoring results that exceeded the final Primary Drinking Water Standards (PDWS) or the Savannah River Site (SRS) flagging criteria or turbidity standard during the quarter are the focus of this report. Tritium exceeded the final PDWS in wells HAC 1, 2, 3, and 4 during fourth quarter 1992. Tritium activities in upgradient well HAC 4 were similar to tritium levels in wells HAC 1, 2, and 3. Iron was elevated in well HAC 1, 2, and 3. Specific conductance and manganese were elevated in one downgradient well each. No well samples exceeded the SRS turbidity standard. During 1992, tritium was the only constituent that exceeded the final PDWS. It did so consistently in all four wells during all four quarters, with little variability in activity

Scintigraphy in the detection of gastro-oesophageal reflux in children with caustic oesophageal burns: a comparative study with radiography and 24-h pH monitoring

Energy Technology Data Exchange (ETDEWEB)

Oezcan, Z.; Erinc, R.; Dirlik, A. [Dept. of Nuclear Medicine, Ege University Medical Faculty, Izmir (Turkey); Oezcan, C.; Mutaf, O. [Dept. of Paediatric Surgery, Ege University Medical Faculty, Izmir (Turkey)

2001-10-01

Background: Caustic injury of the oesophagus not only causes luminal narrowing but is also responsible for longitudinal contraction, resulting in gastro-oesophageal reflux (GOR), which leads to failure of conventional therapy. Therefore, the development of GOR should be investigated periodically to direct appropriate management of these patients. Purpose: To determine the ability of scintigraphy to detect GOR in children with caustic oesophageal strictures in comparison with barium study and 24-h pH monitoring. Materials and methods: Seventeen children with caustic oesophageal injury underwent scintigraphy, an upper GI barium study and 24-h pH monitoring within the same week. Five patients were also investigated post-operatively for the assessment of surgical outcome after antireflux surgery. Results: On the whole, there was good correlation (r = 0.78, P < 0.00 l) between scintigraphy and 24-h oesophageal pH monitoring. Scintigraphy detected all but one (9/10) refluxing patients and also correctly identified all (7/7) non-refluxing patients. Barium studies demonstrated 6 out of 10 refluxing patients. There were no false-positive barium studies in non-refluxing patients. Post-operative studies demonstrated no evidence of GOR in surgically treated patients. Conclusions: Our results indicate that, by comparison with barium studies, scintigraphy is useful in the detection of GOR in cases with caustic oesophageal strictures and may be used as a screening modality for those under clinical follow-up. (orig.)

Development of a solvent extraction process for cesium removal from SRS tank waste

International Nuclear Information System (INIS)

Leonard, R.A.; Conner, C.; Liberatore, M.W.; Sedlet, J.; Aase, S.B.; Vandegrift, G.F.; Delmau, L.H.; Bonnesen, P.V.; Moyer, B.A.

2001-01-01

An alkaline-side solvent extraction process was developed for cesium removal from Savannah River Site (SRS) tank waste. The process was invented at Oak Ridge National Laboratory and developed and tested at Argonne National Laboratory using singlestage and multistage tests in a laboratory-scale centrifugal contactor. The dispersion number, hydraulic performance, stage efficiency, and general operability of the process flowsheet were determined. Based on these tests, further solvent development work was done. The final solvent formulation appears to be an excellent candidate for removing cesium from SRS tank waste.

Water washes and caustic leaches of sludge from Hanford Tank S-101 and water washes of sludge from Hanford Tank C-103

International Nuclear Information System (INIS)

Hunt, R.D.; Collins, J.L.; Chase, C.W.

1998-07-01

In 1993, the Department of Energy (DOE) selected the enhanced sludge washing (ESW) process as the baseline for pretreatment of Hanford tank sludges. The ESW process uses a series of water washes and caustic leaches to separate nonradioactive components such as aluminum, chromium, and phosphate from the high-level waste sludges. If the ESW process is successful, the volume of immobilized high-level waste will be significantly reduced. The tests on the sludge from Hanford Tank S-101 focused on the effects of process variables such as sodium hydroxide concentration (1 and 3 M), temperature (70 and 95 C), and leaching time (5, 24, 72, and 168 h) on the efficacy of the ESW process with realistic liquid-to-solid ratios. Another goal of this study was to evaluate the effectiveness of water washes on a sludge sample from hanford Tank C-103. The final objective of this study was to test potential process control monitors during the water washes and caustic leaches with actual sludge. Both 137 Cs activity and conductance were measured for each of the water washes and caustic leaches. Experimental procedures, a discussion of results, conclusions and recommendations are included in this report

A comparative study on the effect of solvent on nucleophilic fluorination with [18F]fluoride. Protic solvents as co-solvents in SN2 and SNAr reactions

International Nuclear Information System (INIS)

Koivula, T.; Simecek, J.; Jalomaeki, J.; Helariutta, K.; Airaksinen, A.J.

2011-01-01

The effect of solvent on nucleophilic substitution with cyclotron-produced [ 18 F]fluoride was studied in polar aprotic (CH 3 CN and DMF) and protic solvent (t-BuOH and t-amyl alcohol) mixtures (CH 3 CN/co-solvent, 2:8) in a series of model compounds, 4-(R 1 -methyl)benzyl R 2 -benzoates, using a K2.2.2/[ 18 F]KF phase transfer system (R 1 = -Cl, -OMs or -OH; R 2 = -Cl, -I or -NO 2 ). 18 F-fluorination of compounds 1-3, with chloride or mesylate as a leaving group in the benzylic position (R 1 ), afforded the desired 4-([ 18 F]fluoromethyl)benzyl analogues in all solvents during 15 min reaction time. The highest radiochemical yields (RCY) in all the studied reaction temperatures (80, 120 and 160 C) were achieved in CH 3 CN. Radiochemical yields in protic solvents were comparable to RCY in CH 3 CN only with the sulfonate ester 3 as a starting material. 18 F-Fluorination of the benzylic halides 1 and 2 was not promoted in the same extent; in addition, labelled side-products were detected at higher reaction temperatures. Radiofluorination in tert-alcohols was also studied using [ 18 F]CsF with and without added phase transfer catalyst, resulting in both conditions lower RCY when compared to K2.2.2/[ 18 F]KF system. Protic solvents were not able to promote aromatic 18 F-fluorination. 18 F-Fluorination of compound 5, having para-activated nitro group in the aromatic position (R 2 ), failed in tert-alcohols even at the highest temperature, but it was labelled successfully in DMF and to some extent in CH 3 CN. (orig.)

Comparing side chain packing in soluble proteins, protein-protein interfaces, and transmembrane proteins.

Science.gov (United States)

Gaines, J C; Acebes, S; Virrueta, A; Butler, M; Regan, L; O'Hern, C S

2018-05-01

We compare side chain prediction and packing of core and non-core regions of soluble proteins, protein-protein interfaces, and transmembrane proteins. We first identified or created comparable databases of high-resolution crystal structures of these 3 protein classes. We show that the solvent-inaccessible cores of the 3 classes of proteins are equally densely packed. As a result, the side chains of core residues at protein-protein interfaces and in the membrane-exposed regions of transmembrane proteins can be predicted by the hard-sphere plus stereochemical constraint model with the same high prediction accuracies (>90%) as core residues in soluble proteins. We also find that for all 3 classes of proteins, as one moves away from the solvent-inaccessible core, the packing fraction decreases as the solvent accessibility increases. However, the side chain predictability remains high (80% within 30°) up to a relative solvent accessibility, rSASA≲0.3, for all 3 protein classes. Our results show that ≈40% of the interface regions in protein complexes are "core", that is, densely packed with side chain conformations that can be accurately predicted using the hard-sphere model. We propose packing fraction as a metric that can be used to distinguish real protein-protein interactions from designed, non-binding, decoys. Our results also show that cores of membrane proteins are the same as cores of soluble proteins. Thus, the computational methods we are developing for the analysis of the effect of hydrophobic core mutations in soluble proteins will be equally applicable to analyses of mutations in membrane proteins. © 2018 Wiley Periodicals, Inc.

Study of chemical cleaning technique for removing sludge in secondary side of PWR SG

International Nuclear Information System (INIS)

Zhang Mengqin; Zhang Shufeng; Pan Qingchun; Yu Jinghua; Hou Shufeng

1993-12-01

The effect of components, concentration, pH, temperature, cleaning time and flowrate of chemical cleaning solvent made from EDTA mainly on Fe 3 O 4 solubility and corrosion rate of A3 carbon steel, S271 low alloy steel and 800 alloy are introduced. A small chemical cleaning test loop (30L) was built to study the cleaning technique. The effect of residue of chemical cleaning solvent on anti-corrosion performance of materials has been studied under the simulation condition of PWR (pressure water reactor) SG (steam generator) secondary side. The results show that the chemical solvent (pH = 7, 10% EDTA, 1% assistance solvent and 0.25% inhibitor A) can dissolve Fe 3 O 4 18 ∼23 g/L under the conditions of 93 +- 5 degree C, 8 hours and 112 r/min (1.8 ∼ 2.0 t/h). The corrosion rate of material is low. When the residue of EDTA is less than 0.01% there is no impact on the anti-corrosion performance of materials in PWR SG secondary side at normal operation condition (260 +- 5 degree C)

Discovery and Characterization of a Caustic Crossing Microlensing Event in the Small Magellanic Cloud

International Nuclear Information System (INIS)

Alcock, C.; Allsman, R.A.; Alves, D.; Axelrod, T.S.; Becker, A.C.; Bennett, D.P.; Cook, K.H.; Drake, A.J.; Freeman, K.C.; Griest, K.; King, L.J.; Lehner, M.J.; Marshall, S.L.

1999-01-01

We present photometric observations and analysis of the second microlensing event detected toward the Small Magellanic Cloud (SMC), MACHO Alert 98-SMC-1. This event was detected early enough to allow intensive observation of the light curve. These observations revealed 98-SMC-1 to be the first caustic crossing binary microlensing event toward the Magellanic Clouds to be discovered in progress. Frequent coverage of the evolving light curve allowed an accurate prediction for the date of the source crossing out of the lens caustic structure. The caustic crossing temporal width, along with the angular size of the source star, measures the proper motion of the lens with respect to the source and thus allows an estimate of the location of the lens. Lenses located in the Galactic halo would have a velocity projected to the SMC of v∼1500 kms -1 , while an SMC lens would typically have v∼60 kms -1 . The event light curve allows us to obtain a unique fit to the parameters of the binary lens and to estimate the proper motion of the lensing system. We have performed a joint fit to the MACHO/GMAN data presented here, including recent EROS data of this event from Afonso and collaborators. These joint data are sufficient to constrain the time t * for the lens to move an angle equal to the source angular radius: t * =0.116±0.010 days. We estimate a radius for the lensed source of R * =1.1±0.1 R circle-dot from its unblended color and magnitude. This yields a projected velocity of v=76±10 kms -1 . Only 0.12% of halo lenses would be expected to have a v value at least as small as this, while 38% of SMC lenses would be expected to have v as large as this. This implies that the lensing system is more likely to reside in the SMC than in the Galactic halo. Similar observations of future Magellanic Cloud microlensing events will help to determine the contribution of MACHOS to the Galaxy's dark halo. copyright copyright 1999. The American Astronomical Society

Extensive caustic esophageal stricture in children can be treated by serial dilatations interspersed with silicone-covered nitinol stenting

Directory of Open Access Journals (Sweden)

Veronica Alonso

2016-01-01

Full Text Available Recurrent esophageal stenosis secondary to caustic ingestion may be challenging to treat. Self-expandable esophageal stents may be an alternative to repetitive endoscopic esophageal dilatation. We report a case of a 2-year-old male child with an extensive esophageal caustic stricture successfully treated using a combination of endoscopic dilatation and stenting. After 5 months of serial balloon dilatations, three nitinol internal silicone covered self-expandable stents were placed through the patient′s gastrostomy spanning the entire esophagus. The stents were positioned using a combination of both endoscopic and fluoroscopic guidance. The procedure was repeated with only one stent 3 months later. A new stricture in the proximal esophagus needed surgical resection and anastomosis, followed by two pneumatic dilatations with progressively longer asymptomatic intervals. The results are promising with the patient able to use his own esophagus; however, this is a single case and optimal stent standing time is still to be determined.

PROJECT W-551 DETERMINATION DATA FOR EARLY LAW INTERIM PRETREATMENT SYSTEM SELECTION

Energy Technology Data Exchange (ETDEWEB)

TEDESCHI AR

2008-08-11

This report provides the detailed assessment forms and data for selection of the solids separation and cesium separation technology for project W-551, Interim Pretreatment System. This project will provide early pretreated low activity waste feed to the Waste Treatment Plant to allow Waste Treatment Plan Low Activity Waste facility operation prior to construction completion of the Pretreatment and High Level Waste facilities. The candidate solids separations technologies are rotary microfiltration and crossflow filtration, and the candidate cesium separation technologies are fractional crystallization, caustic-side solvent extraction, and ion-exchange using spherical resorcinol-formaldehyde resin. This data was used to prepare a cross-cutting technology summary, reported in RPP-RPT-37740.

Accuracy of Endoscopy in Predicting the Depth of Mucosal Injury Following Caustic Ingestion; a Cross-Sectional Study

Directory of Open Access Journals (Sweden)

Athena Alipour-Faz

2017-01-01

Full Text Available Introduction: Esophagogastroduodenoscopy (EGD is currently considered as the primary method of determining the degree of mucosal injury following caustic ingestion. The present study aimed to evaluate the screening performance characteristics of EGD in predicting the depth of gastrointestinal mucosal injuries following caustic ingestion.Methods: Adult patients who were referred to emergency department due to ingestion of corrosive materials, over a 7-year period, were enrolled to this diagnostic accuracy study. Sensitivity, specificity, positive and negative predictive values as well as negative and positive likelihood ratios of EGD in predicting the depth of mucosal injury was calculated using pathologic findings as the gold standard.Results: 54 cases with the mean age of 35 ± 11.2 years were enrolled (59.25% male. Primary endoscopic results defined 28 (51.85% cases as second grade and 26 (48.14% as third grade of mucosal injury. On the other hand, pathologic findings reported 21 (38.88% patients as first grade, 14 (25.92% as second, and 19 patients (35.18% as third grade. Sensitivity and specificity of endoscopy for determining grade II tissue injury were 50.00 (23.04-76.96 and 47.50 (31.51-63.87, respectively. These measures were 100.00 (82.35-100 and 80.00 (63.06-91.56, respectively for grade III. Accuracy of EGD was 87.03% for grade III and 48.14% for grade II.Conclusion: Based on the findings of the present study, endoscopic grading of caustic related mucosal injury based on the Zargar’s classification has good accuracy in predicting grade III (87% and fail accuracy in grade II injuries (48%. It seems that we should be cautious in planning treatment for these patients solely based on endoscopic results. 

Energy conversion performance of black liquor gasification to hydrogen production using direct causticization with CO(2) capture.

Science.gov (United States)

Naqvi, M; Yan, J; Dahlquist, E

2012-04-01

This paper estimates potential hydrogen production via dry black liquor gasification system with direct causticization integrated with a reference pulp mill. The advantage of using direct causticization is elimination of energy intensive lime kiln. Pressure swing adsorption is integrated in the carbon capture process for hydrogen upgrading. The energy conversion performance of the integrated system is compared with other bio-fuel alternatives and evaluated based on system performance indicators. The results indicated a significant hydrogen production potential (about 141MW) with an energy ratio of about 0.74 from the reference black liquor capacity (about 243.5MW) and extra biomass import (about 50MW) to compensate total energy deficit. About 867,000tonnes of CO(2) abatement per year is estimated i.e. combining CO(2) capture and CO(2) offset from hydrogen replacing motor gasoline. The hydrogen production offers a substantial motor fuel replacement especially in regions with large pulp and paper industry e.g. about 63% of domestic gasoline replacement in Sweden. Copyright © 2012 Elsevier Ltd. All rights reserved.

Synthetic gas production from dry black liquor gasification process using direct causticization with CO2 capture

International Nuclear Information System (INIS)

Naqvi, Muhammad; Yan, Jinyue; Dahlquist, Erik

2012-01-01

Highlights: ► We study synthetic gas production from dry black liquor gasification system. ► Direct causticization eliminates energy intensive lime kiln reducing biomass use. ► Results show large SNG production potential at significant energy efficiency (58%). ► Substantial CO 2 capture potential plus CO 2 reductions from natural gas replacement. ► Significant transport fuel replacement especially in Sweden and Europe. -- Abstract: Synthetic natural gas (SNG) production from dry black liquor gasification (DBLG) system is an attractive option to reduce CO 2 emissions replacing natural gas. This article evaluates the energy conversion performance of SNG production from oxygen blown circulating fluidized bed (CFB) black liquor gasification process with direct causticization by investigating system integration with a reference pulp mill producing 1000 air dried tonnes (ADt) of pulp per day. The direct causticization process eliminates use of energy intensive lime kiln that is a main component required in the conventional black liquor recovery cycle with the recovery boiler. The paper has estimated SNG production potential, the process energy ratio of black liquor (BL) conversion to SNG, and quantified the potential CO 2 abatement. Based on reference pulp mill capacity, the results indicate a large potential of SNG production (about 162 MW) from black liquor but at a cost of additional biomass import (36.7 MW) to compensate the total energy deficit. The process shows cold gas energy efficiency of about 58% considering black liquor and biomass import as major energy inputs. About 700 ktonnes per year of CO 2 abatement i.e. both possible CO 2 capture and CO 2 offset from bio-fuel use replacing natural gas, is estimated. Moreover, the SNG production offers a significant fuel replacement in transport sector especially in countries with large pulp and paper industry e.g. in Sweden, about 72% of motor gasoline and 40% of total motor fuel could be replaced.

Covalent Surface Modification of Silicon Oxides with Alcohols in Polar Aprotic Solvents.

Science.gov (United States)

Lee, Austin W H; Gates, Byron D

2017-09-05

Alcohol-based monolayers were successfully formed on the surfaces of silicon oxides through reactions performed in polar aprotic solvents. Monolayers prepared from alcohol-based reagents have been previously introduced as an alternative approach to covalently modify the surfaces of silicon oxides. These reagents are readily available, widely distributed, and are minimally susceptible to side reactions with ambient moisture. A limitation of using alcohol-based compounds is that previous reactions required relatively high temperatures in neat solutions, which can degrade some alcohol compounds or could lead to other unwanted side reactions during the formation of the monolayers. To overcome these challenges, we investigate the condensation reaction of alcohols on silicon oxides carried out in polar aprotic solvents. In particular, propylene carbonate has been identified as a polar aprotic solvent that is relatively nontoxic, readily accessible, and can facilitate the formation of alcohol-based monolayers. We have successfully demonstrated this approach for tuning the surface chemistry of silicon oxide surfaces with a variety of alcohol containing compounds. The strategy introduced in this research can be utilized to create silicon oxide surfaces with hydrophobic, oleophobic, or charged functionalities.

Solvent effect on the rate and equilibrium of reaction between 10-phenylphenoxarsine and methyl iodide

International Nuclear Information System (INIS)

Gavrilov, V.I.; Gumerov, N.S.; Rakhmatullin, R.R.

1990-01-01

Effect of solvent nature on nucleophilic capacity of three-coordinated arsenic and the equilibrium state of 10-phenylphenoxarsine (PA) reaction with methyl iodide are studied. Kinetic investigations are carried out by the conductometry at 24,35,45 deg C. It is established that quaternization of PA with methyl iodide when substituting a solvent (ketone for alcohol) increases 3-14 times with simultaneous growth of the activation energy value. When transforming from aprotic solvents to protic ones PA interaction equilibrium with methyl iodide shifts to the side of arsonic salt formation

Characterization of solids deposited on the modular caustic-side solvent extraction unit (MCU) coalescer media removed in October 2014

Energy Technology Data Exchange (ETDEWEB)

Fondeur, F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2016-03-01

In February 2015, Savannah River National Laboratory (SRNL) received a Strip Effluent (SE) coalescer (FLT-304) from MCU. That coalescer was first installed at MCU in July 2014 and removed in October 2014. While processing approximately 31,400 gallons of strip solution, the pressure drop steadily increased from 1 psi to beyond the administrative limit of 20 psi. The physical and chemical analysis was conducted on this coalescer to determine the mechanism that led to the plugging of this coalescer. Characterization of this coalescer revealed the adsorption of organic containing amines as well as MCU modifier. The amines are probably from the decomposition of the suppressor (TiDG) as well as from bacteria. This adsorption may have changed the surface energetics (characteristics) of the coalescer fibers and therefore, their wetting behavior. A very small amount of inorganic solids were found to have deposited on this coalescer (possibly an artifact of cleaning the coalescer with Boric acid. However, we believe that inorganic precipitation, as has been seen in the past, did not play a role in the high pressure drop rise of this coalescer. With regards to the current practice of reducing the radioactive content of the SE coalescer, it is recommended that future SE coalescer should be flushed with 10 mM boric acid which is currently used at MCU. Plugging of the SE coalescer was most likely due to the formation and accumulation of a water-in-oil emulsion that reduced the overall porosity of the coalescer. There is also evidence that a bimodal oil particle distribution may have entered and deposited in the coalescer and caused the initial increase in pressure drop.

Membrane assisted solvent extraction for rare earth element recovery

Science.gov (United States)

Bhave, Ramesh R.; Kim, Daejin; Peterson, Eric S.

2018-05-15

Systems and methods for the recovery of rare earth elements are provided. The systems and methods generally include membrane assisted solvent extraction using permeable hollow fibers having an immobilized organic phase within the pores of the hollow fibers. The permeable hollow fibers are generally in contact with an acidic aqueous feed on one side thereof and a strip solution on another side thereof. The systems and methods generally include the simultaneous extraction and stripping of rare earth elements as a continuous recovery process that is well suited for post-consumer products, end-of-life products, and other recovery sources of rare earth elements.

Analysis of an MCU HEPA filter

Energy Technology Data Exchange (ETDEWEB)

Peters, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Fondeur, F. F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-01-01

A series of direct analyses on three portions (inlet, center, and outlet) of the High Efficiency Particulate Air (HEPA) filter material from the Modular Caustic-Side Solvent Extraction Unit (MCU) have been performed; this includes x-ray methods such as X-Ray Diffraction (XRD), Contained Scanning Electron Microscopy (CSEM) and X-Ray Fluorescence (XRF), as well as Fourier Transform InfraRed spectroscopy (FTIR). Additionally, two leaching studies (one with water, one with dichloromethane) have been performed on three portions (inlet, center, and outlet) of the HEPA filter material, with the leachates being analyzed by Inductively-coupled plasma emission spectroscopy (ICPES), Semi-Volatile Organic Analysis (SVOA) and gammascan. From the results of the analyses, SRNL feels that cesium-depleted solvent is being introduced into the HEPA filter. The most likely avenue for this is mechanical aerosolization of solvent, where the aerosol is then carried along an airstream into the HEPA filter. Once introduced into the HEPA filter media, the solvent wicks throughout the material, and migrates towards the outlet end. Once on the outlet end, continual drying could cause particulate flakes to exit the filter and travel farther down the airstream path.

The behaviour of organic solvents containing C5-BTBP and CyMe4-BTBP at low irradiation doses

International Nuclear Information System (INIS)

Retegan, T.; Fermvik, A.; Skarnemark, G.; Foreman, M.R.S.

2007-01-01

Low doses of gamma radiation were given to four different solvents containing C5-BTBP and CyMe 4 -BTBP, each molecule dissolved both in cyclohexanone and hexanol. Four corresponding solvents were kept unirradiated and used as references for the extraction experiments. Multiple samples were taken from both the irradiated solutions and the reference solutions at certain time intervals. The samples were used in extraction experiments with the radionuclides 241 Am and 152 Eu. The protection against radiolysis of the extracting molecules by the diluent used for dissolution without adding a scavenger molecule was checked. The interplay between the diluent and the side group of the extracting molecule for protection against radiolysis was also studied by keeping the same type of core molecule for binding to the metal ions and varying the diluent and side group. The results were unexpected. The presence of a cyclic molecule as both a side group or diluent seems to keep the extraction of europium almost unaffected by radiolysis, while americium behaves differently from solvent to solvent. The diluent alone does not protect the extracting molecule. In some of the studied systems there is a distinct change in the extraction behaviour of Am between the irradiated and reference solutions, an effect that is however only present at the beginning of the experimental series. At later times the difference in distribution ratios between the irradiated and reference solution is constant. This phenomenon is found only when the side group and diluent are structurally dissimilar. (orig.)

Solvent selection methodology for pharmaceutical processes: Solvent swap

DEFF Research Database (Denmark)

Papadakis, Emmanouil; Kumar Tula, Anjan; Gani, Rafiqul

2016-01-01

A method for the selection of appropriate solvents for the solvent swap task in pharmaceutical processes has been developed. This solvent swap method is based on the solvent selection method of Gani et al. (2006) and considers additional selection criteria such as boiling point difference...... in pharmaceutical processes as well as new solvent swap alternatives. The method takes into account process considerations such as batch distillation and crystallization to achieve the swap task. Rigorous model based simulations of the swap operation are performed to evaluate and compare the performance...

Ionospheric Caustics in Solar Radio Observations

Science.gov (United States)

Koval, A.; Chen, Y.; Stanislavsky, A.

2016-12-01

The Earth ionosphere possesses by natural focusing and defocusing effects on radio waves due to presence of variable ionospheric irregularities which could act like convergent and divergent lenses on incident radiation. In particular, the focusing of emission from the Sun was firstly detected on the Nançay Decameter Array dynamic spectra in the 1980s. On time-frequency spectrograms the intensity variations form specific structures different from well-known solar radio bursts and clearly distinguishing on a background of solar radiation. Such structures have been identified as ionospheric caustics (ICs) and considered to be the result of radio waves refraction on medium scale travelling ionospheric disturbances (MSTIDs). Although nowadays the ICs are registered by different radio observatories due to augmentation of low-frequency radio telescopes, the most recent papers devoted to ICs in solar radio records date back to the 1980s. In this study, we revisit the ICs issue with some new results by conducting a statistical analysis of occurrence rate of ICs in solar dynamic spectra in meter-decameter wavelength range for long continuous period (15 years). The seasonal variations in ICs appearance have been found for the first time. Besides, we report the possible solar cycle dependence of ICs emergence. The radio waves propagation in the ionosphere comprising MSTIDs will be considered. The present research renews the subject of ICs in the low-frequency solar radio astronomy after about 35-year letup.

Predictive Factors of Gastrointestinal Caustic Injury According to Clinical and Endoscopic Findings

Directory of Open Access Journals (Sweden)

Cherie Quingking

2013-03-01

Full Text Available Background: Ingestion of caustic substances is the main reason for referral to Philippines National Poison Management and Control Center among other causes of acute poisoning. Rapid assessment of severity of injury is important for treatment and prognosis of these cases. This study was aimed to investigate the correlation of clinical factors with severity of gastrointestinal (GI mucosal injury. Methods: In this retrospective study, a total of 105 patients were included. Patients were categorized into two groups including 35 patients with low grade and 70 patients with high grade GI injury to compare the predictive value of clinical findings. Results: Mean (SD age of patients was 27 (10 and 47% of patients were male. Oral burns (P

Results of initial analyses of the salt (macro) batch 11 Tank 21H qualification samples

Energy Technology Data Exchange (ETDEWEB)

Peters, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-10-23

Savannah River National Laboratory (SRNL) analyzed samples from Tank 21H in support of qualification of Interim Salt Disposition Project (ISDP) Salt (Macro) Batch 11 for processing through the Actinide Removal Process (ARP) and the Modular Caustic-Side Solvent Extraction Unit (MCU). This document reports the initial results of the analyses of samples of Tank 21H. Analysis of the Tank 21H Salt (Macro) Batch 11 composite sample indicates that the material does not display any unusual characteristics or observations, such as floating solids, the presence of large amounts of solids, or unusual colors. Further sample results will be reported in a future document. This memo satisfies part of Deliverable 3 of the Technical Task Request (TTR).

Effects of microstructure and mechanical properties of alloys 600 an 690 on secondary side SCC

International Nuclear Information System (INIS)

Vaillant, F.; Buisine, D.; Prieux, B.; Fournel, J.C.; Gelpi, A.

1996-03-01

Modeling for secondary side cracking is needed to understand the behaviour of alloy 600 in plants. They require a comprehensive understanding of the various influences of the material properties on Stress Corrosion Cracking (SCC), based on field experience and laboratory data. In an attempt to predict the materials effects on SCC behaviour of new steam generators, laboratory corrosion data of alloy 690 were overviewed. French field experience with steam generators equipped with drilled tube support plates (TSPs) has demonstrated that the lower the yield stress (YS) and the carbon content, the higher the susceptibility t secondary side cracking of mill-annealed (MA) alloy 600. Also heat treated (700 deg. C x 16 h) tubing has been shown to have a much better resistance, but this excellent resistance could not be attributed only to the material properties. In laboratory environments, particularly in caustics, results have confirmed several of the above mentioned key findings on alloy 600: in caustic environments and under constant loading, tubes fabricated from MA alloy 600 with low YS have exhibited the worst resistance to initiation; YS was found to be the most accurate parameter to account for the behaviour of MA alloy 600. A heat treatment at 700 deg. C appeared to reduce the propagation rates of cracks in alloy 600. The best IGSCC resistance of alloy 690 was obtained for tubes with intergranular precipitation of carbides. TT (700 deg. C) significantly improved the propagation resistance of alloy 690; in acidic and neutral sulfate environments, IGSCC of alloy 600 was not strongly dependent on the microstructure in the MA condition, but sensitization was detrimental. When alloy 600 and particularly alloy 690 were thermally treated at 700 deg. C x 16 h, the resistance to IGSCC was significantly improved. Tests performed on alloy 690 have shown a better resistance to IGSCC initiation and propagation than alloy 600, in NaOH and acidic sulfate environments. (authors

Preliminary Evaluation Of DWPF Impacts Of Boric Acid Use In Cesium Strip FOR SWPF And MCU

International Nuclear Information System (INIS)

Stone, M.

2010-01-01

A new solvent system is being evaluated for use in the Modular Caustic-Side Solvent Extraction Unit (MCU) and in the Salt Waste Processing Facility (SWPF). The new system includes the option to replace the current dilute nitric acid strip solution with boric acid. To support this effort, the impact of using 0.01M, 0.1M, 0.25M and 0.5M boric acid in place of 0.001M nitric acid was evaluated for impacts on the DWPF facility. The evaluation only covered the impacts of boric acid in the strip effluent and does not address the other changes in solvents (i.e., the new extractant, called MaxCalix, or the new suppressor, guanidine). Boric acid additions may lead to increased hydrogen generation during the SRAT and SME cycles as well as change the rheological properties of the feed. The boron in the strip effluent will impact glass composition and could require each SME batch to be trimmed with boric acid to account for any changes in the boron from strip effluent additions. Addition of boron with the strip effluent will require changes in the frit composition and could lead to changes in melt behavior. The severity of the impacts from the boric acid additions is dependent on the amount of boric acid added by the strip effluent. The use of 0.1M or higher concentrations of boric acid in the strip effluent was found to significantly impact DWPF operations while the impact of 0.01M boric acid is expected to be relatively minor. Experimental testing is required to resolve the issues identified during the preliminary evaluation. The issues to be addressed by the testing are: (1) Impact on SRAT acid addition and hydrogen generation; (2) Impact on melter feed rheology; (3) Impact on glass composition control; (4) Impact on frit production; and (5) Impact on melter offgas. A new solvent system is being evaluated for use in the Modular Caustic-Side Solvent Extraction Unit (MCU) and in the Salt Waste Processing Facility (SWPF). The new system includes the option to replace the

Washing and caustic leaching of Hanford tank sludges

International Nuclear Information System (INIS)

Lumetta, G.J.; Rapko, B.M.; Colton, N.G.

1994-01-01

Methods are being developed to treat and dispose of large volumes of radioactive wastes stored in underground tanks at the U.S. Department of Energy's Hanford Site. The wastes will be partitioned into high-level waste (HLW) and low-level waste (LLW) fractions. The HLW will be vitrified into borosilicate glass and disposed of in a geologic repository, while the LLW will be immobilized in a glass matrix and will likely be disposed of by shallow burial at the Hanford Site. The wastes must be pretreated to reduce the volume of the HLW fraction, so that vitrification and disposal costs can be minimized. The current baseline process for pretreating Hanford tank sludges is to leach the sludge under caustic conditions, then remove the solubilized components of the sludge by water washing. Tests of this method have been performed with samples taken from several different tanks at Hanford. The results of these tests are presented in terms of the composition of the sludge before and after leaching. X-ray diffraction and scanning electron microscopy coupled with electron dispersive x-ray techniques have been used to identify the phases in the untreated and treated sludges

Solvent extraction

Energy Technology Data Exchange (ETDEWEB)

Coombs, D.M.; Latimer, E.G.

1988-01-05

It is an object of this invention to provide for the demetallization and general upgrading of heavy oil via a solvent extracton process, and to improve the efficiency of solvent extraction operations. The yield and demetallization of product oil form heavy high-metal content oil is maximized by solvent extractions which employ either or all of the following techniques: premixing of a minor amount of the solvent with feed and using countercurrent flow for the remaining solvent; use of certain solvent/free ratios; use of segmental baffle tray extraction column internals and the proper extraction column residence time. The solvent premix/countercurrent flow feature of the invention substantially improves extractions where temperatures and pressures above the critical point of the solvent are used. By using this technique, a greater yield of extract oil can be obtained at the same metals content or a lower metals-containing extract oil product can be obtained at the same yield. Furthermore, the premixing of part of the solvent with the feed before countercurrent extraction gives high extract oil yields and high quality demetallization. The solvent/feed ratio features of the invention substanially lower the captial and operating costs for such processes while not suffering a loss in selectivity for metals rejection. The column internals and rsidence time features of the invention further improve the extractor metals rejection at a constant yield or allow for an increase in extract oil yield at a constant extract oil metals content. 13 figs., 3 tabs.

Next Generation Extractants for Cesium Separation from High-Level Waste: From Fundamental Concepts to Site Implementation

International Nuclear Information System (INIS)

Moyer, Bruce A.; Bazelaire, Eve; Bonnesen, Peter V.; Bryan, Jeffrey C.; Delmau, Latitia H.; Engle, Nancy L.; Gorbunova, Maryna G.; Keever, Tamara J.; Levitskaia, Tatiana G.; Sachleben, Richard A.; Tomkins, Bruce A.; Bartsch, Richard A.

2004-01-01

General project objectives. This project seeks a fundamental understanding and major improvement in cesium separation from high-level waste by cesium-selective calixcrown extractants. Systems of particular interest involve novel solvent-extraction systems containing specific members of the calix[4]arene-crown-6 family, alcohol solvating agents, and alkylamines. Questions being addressed pertain to cesium binding strength, extraction selectivity, cesium stripping, and extractant solubility. Enhanced properties in this regard will specifically benefit cleanup projects funded by the USDOE Office of Environmental Management to treat and dispose of high-level radioactive wastes currently stored in underground tanks at the Savannah River Site (SRS), the Hanford site, and the Idaho National Environmental and Engineering Laboratory.1 The most direct beneficiary will be the SRS Salt Processing Project, which has recently identified the Caustic-Side Solvent Extraction (CSSX) process employing a calixcrown as its preferred technology for cesium removal from SRS high level tank waste.2 This technology owes its development in part to fundamental results obtained in this program

Next Generation Extractants for Cesium Separation from High-Level Waste: From Fundamental Concepts to Site Implementation

International Nuclear Information System (INIS)

Moyer, Bruce A; Bazelaire, Eve; Bonnesen, Peter V.; Bryan, Jeffrey C.; Delmau, Laetitia H.; Engle, Nancy L.; Gorbunova, Maryna G.; Keever, Tamara J.; Levitskaia, Tatiana G.; Sachleben, Richard A.; Tomkins, Bruce A.; Bartsch, Richard A.; Talanov, Vladimir S.; Gibson, Harry W.; Jones, Jason W.; Hay, Benjamin P.

2003-01-01

This project seeks a fundamental understanding and major improvement in cesium separation from high-level waste by cesium-selective calixcrown extractants. Systems of particular interest involve novel solvent-extraction systems containing specific members of the calix[4]arene-crown-6 family, alcohol solvating agents, and alkylamines. Questions being addressed pertain to cesium binding strength, extraction selectivity, cesium stripping, and extractant solubility. Enhanced properties in this regard will specifically benefit cleanup projects funded by the USDOE Office of Environmental Management to treat and dispose of high-level radioactive wastes currently stored in underground tanks at the Savannah River Site (SRS), the Hanford site, and the Idaho National Environmental and Engineering Laboratory.1 The most direct beneficiary will be the SRS Salt Processing Project, which has recently identified the Caustic-Side Solvent Extraction (CSSX) process employing a calixcrown as its preferred technology for cesium removal from SRS high-level tank waste.2 This technology owes its development in part to fundamental results obtained in this program

ISDP salt batch #2 supernate qualification

Energy Technology Data Exchange (ETDEWEB)

Peters, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Nash, C. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Fink, S. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2009-01-05

This report covers the laboratory testing and analyses of the second Integrated Salt Disposition Project (ISDP) salt supernate samples, performed in support of initial radioactive operations of Actinide Removal Process (ARP) and Modular Caustic-Side Solvent Extraction Unit (MCU). Major goals of this work include characterizing Tank 22H supernate, characterizing Tank 41H supernate, verifying actinide and strontium adsorption with a standard laboratory-scale test using monosodium titanate (MST) and filtration, and checking cesium mass transfer behavior for the MCU solvent performance when contacted with the liquid produced from MST contact. This study also includes characterization of a post-blend Tank 49H sample as part of the Nuclear Criticality Safety Evaluation (NCSE). This work was specified by Task Technical Request and by Task Technical and Quality Assurance Plan (TTQAP). In addition, a sampling plan will be written to guide analytical future work. Safety and environmental aspects of the work were documented in a Hazard Assessment Package.

Boiler and HRSG tube failures. Lesson 5. Caustic gouging

Energy Technology Data Exchange (ETDEWEB)

Dooley, Barry R.; Bursik, Albert

2010-03-15

University 101 courses are typically designed to help incoming first-year undergraduate students to adjust to the university, develop a better understanding of the college environment, and acquire essential academic success skills. Why are we offering a special Boiler and HRSG Tube Failures PPChem 101? The answer is simple, yet very conclusive: - There is a lack of knowledge on the identification of tube failure mechanisms and for the implementation of adequate counteractions in many power plants, particularly at industrial power and steam generators. - There is a lack of knowledge to prevent repeat tube failures. The vast majority of BTF/HTF have been, and continue to be, repeat failures. It is hoped that the information about the failure mechanisms of BTF supplied in this course will help to put plant engineers and chemists on the right track. The major goal of this course is the avoidance of repeat BTF. This fifth lesson is focused on caustic gouging of water-touched tubes in conventional boilers and in the high-pressure evaporators of heat recovery steam generators. (orig.)

Canyon solvent cleaning

International Nuclear Information System (INIS)

Reif, D.J.

1986-01-01

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

Distribution of multi-component solvents in solvent vapor extraction chamber

Energy Technology Data Exchange (ETDEWEB)

Das, S. [Society of Petroleum Engineers, Richardson, TX (United States)]|[Marathon Oil Corp., Houston, TX (United States)

2008-10-15

Vapex process performance is sensitive to operating pressures, temperatures and the types of solvent used. The hydrocarbon solvents used in Vapex processes typically have between 5 and 10 per cent hydrocarbon impurities, and the accumulation of dense phases inside the vapor chamber reduces gravity drainage potential. This study investigated the partitioning of solvent compounds inside the vapor chamber during in situ Vapex processes.The aim of the study was to examine how the different components of the mixed solvent partitioned inside the extracted chamber during the oil and vapor phase. A 2-D homogenous reservoir model was used to simulate the Vapex process with a solvent mixture comprised of propane and methane at various percentages. The effect of injecting a hot solvent vapor was also investigated. The study showed that injected methane accumulated at both the top and the extraction interface. Accumulations near the top had a positive impact on solvent confinement in thin reservoirs. Diffusion of the solvent component was controlled by gas phase molecular diffusion, and was much faster than the diffusion of solvent molecules in the liquid phase. The use of hot solvent mixtures slowed the extraction process due to lower solvent solubility in the oil phase. It was concluded that the negative impact on viscosity reduction by dilution was not compensated by rises in temperature. 6 refs., 11 figs.

Biological treatment of refinery spent caustics under halo-alkaline conditions.

Science.gov (United States)

de Graaff, Marco; Bijmans, Martijn F M; Abbas, Ben; Euverink, Gert-J W; Muyzer, Gerard; Janssen, Albert J H

2011-08-01

The present research demonstrates the biological treatment of refinery sulfidic spent caustics in a continuously fed system under halo-alkaline conditions (i.e. pH 9.5; Na(+)= 0.8M). Experiments were performed in identical gas-lift bioreactors operated under aerobic conditions (80-90% saturation) at 35°C. Sulfide loading rates up to 27 mmol L(-1)day(-1) were successfully applied at a HRT of 3.5 days. Sulfide was completely converted into sulfate by the haloalkaliphilic sulfide-oxidizing bacteria belonging to the genus Thioalkalivibrio. Influent benzene concentrations ranged from 100 to 600 μM. At steady state, benzene was removed by 93% due to high stripping efficiencies and biodegradation. Microbial community analysis revealed the presence of haloalkaliphilic heterotrophic bacteria belonging to the genera Marinobacter, Halomonas and Idiomarina which might have been involved in the observed benzene removal. The work shows the potential of halo-alkaliphilic bacteria in mitigating environmental problems caused by alkaline waste. Copyright © 2011 Elsevier Ltd. All rights reserved.

Fermat's principle, caustics, and the classification of gravitational lens images

International Nuclear Information System (INIS)

Blandford, R.; Narayan, R.

1986-01-01

A scalar description of gravitational lensing based on Fermat's principle is described. The lensing mass is assumed to be confined to a single plane between the source and the observer, and a time delay is associated with each position in the sky of a potential image. The extrema of this time surface then give the true positions of the images. A topological classification of image configurations is presented, and the results are generalized to cases of three and five-image lensing geometries. A computer-graphical approach to the study of lensing by model galaxies and clusters is described, and the design of a simple optical apparatus which could be used for fast modelling of image geometries is outlined. The connection between the Fermat approach and the classical theory of caustics and the more recent general theory of catastrophies is developed. The extension of the results to multiple scattering is considered. 42 references

Cleanup of 7.5% tributyl phosphate/n-paraffin solvent-extraction solvent

International Nuclear Information System (INIS)

Reif, D.J.

1987-02-01

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

On the Observability of Individual Population III Stars and Their Stellar-mass Black Hole Accretion Disks through Cluster Caustic Transits

Science.gov (United States)

Windhorst, Rogier A.; Wyithe, Stuart; Alpaslan, Mehmet; Timmes, F. X.; Andrews, Stephen K.; Kim, Duho; Kelly, Patrick; Coe, Dan A.; Diego, Jose M.; Driver, Simon P.; Dijkstra, Mark

2018-06-01

We summarize panchromatic Extragalactic Background Light data to place upper limits on the integrated near-IR surface brightness (SB) that may come from Population III stars and possible accretion disks around their stellar-mass black holes (BHs) in the epoch of First Light, broadly taken from z=7-17.We outline the physical properties of zero-metallicity Population III stars from MESA stellar evolution models through helium depletion and of BH accretion disks at z>7. We assume that second-generation non-zero-metallicity stars can form at higher multiplicity, so that BH accretion disks may be fed by Roche-lobe overflow from lower-mass companions.We use these near-infrared SB constraints to calculate the number of caustic transits behind lensing clusters that the James Webb Space Telescope and the next-generation ground-based telescopes may observe for both Population III stars and their BH accretion disks. Typical caustic magnifications can be 10^4-10^5x, with rise times of hours and decline times of z~Economia y Competitividad of Spain Consolider Project CSD2010-00064.

Co-treatment of spent cathode carbon in caustic and acid leaching process under ultrasonic assisted for preparation of SiC.

Science.gov (United States)

Yuan, Jie; Xiao, Jin; Li, Fachuang; Wang, Bingjie; Yao, Zhen; Yu, Bailie; Zhang, Liuyun

2018-03-01

Spent cathode carbon (SCC) from aluminum electrolysis has been treated in ultrasonic-assisted caustic leaching and acid leaching process, and purified SCC used as carbon source to synthesize silicon carbide (SiC) was investigated. Chemical and mineralogical properties have been characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), and thermogravimetry and differential scanning calorimetry (TGA-DSC). Various experimental factors temperature, time, liquid-solid ratio, ultrasonic power, and initial concentration of alkali or acid affecting on SCC leaching result were studied. After co-treatment with ultrasonic-assisted caustic leaching and acid leaching, carbon content of leaching residue was 97.53%. SiC power was synthesized by carbothermal reduction at 1600 °C, as a result of yield of 76.43%, and specific surface area of 4378 cm 2 /g. This is the first report of using purified SCC and gangue to prepare SiC. The two industrial wastes have been used newly as secondary sources. Furthermore, ultrasonic showed significant effect in SCC leaching process. Copyright © 2017 Elsevier B.V. All rights reserved.

Solvent wash solution

International Nuclear Information System (INIS)

Neace, J.C.

1986-01-01

This patent describes a process for removing diluent degradation products from a solvent extraction solution comprising an admixture of an organic extractant for uranium and plutonium and a non-polar organic liquid diluent, which has been used to recover uranium and plutonium from spent nuclear fuel. Comprising combining a wash solution consisting of: (a) water; and (b) a positive amount up to about, an including, 50 volume percent of at least one highly-polar water-miscible organic solvent, based on the total volume of the water and the highly-polar organic solvent, with the solvent extraction solution after uranium and plutonium values have been stripped from the solvent extraction solution, the diluent degradation products dissolving in the highly-polar organic solvent and the extractant and diluent of the extraction solution not dissolving in the highly-polar organic solvent, and separating the highly-polar organic solvent and the extraction solution to obtain a purified extraction solution

Impaired colour vision in workers exposed to organic solvents: A systematic review.

Science.gov (United States)

Betancur-Sánchez, A M; Vásquez-Trespalacios, E M; Sardi-Correa, C

2017-01-01

To evaluate recent evidence concerning the relationship between the exposure to organic solvents and the impairment of colour vision. A bibliographic search was conducted for scientific papers published in the last 15 years, in the LILACS, PubMed, Science Direct, EBSCO, and Cochrane databases that included observational studies assessing the relationship between impairment in colour vision and exposure to organic solvents. Eleven studies were selected that were performed on an economically active population and used the Lanthony D-15 desaturated test (D-15d), measured the exposure to organic solvents, and included unexposed controls. It was found that there is a statistically significant relationship between the exposure to organic solvents and the presence of an impairment in colour vision. The results support the hypothesis that exposure to organic solvents could induce acquired dyschromatopsia. The evaluation of colour vision with the D-15d test is simple and sensitive for diagnosis. More studies need to be conducted on this subject in order to better understand the relationship between impaired colour vision and more severe side effects caused by this exposure. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

LITERATURE REVIEW OF BORIC ACID SOLUBILITY DATA

Energy Technology Data Exchange (ETDEWEB)

Crapse, K.; Kyser, E.

2011-09-22

A new solvent system is being evaluated for use in the Modular Caustic-Side Solvent Extraction Unit (MCU) and in the Salt Waste Processing Facility (SWPF). The new system replaces the current dilute nitric acid strip solution with 0.01 M boric acid. This literature study is performed to determine if there is a potential for boric acid to crystallize in the lines with emphasis on the transfer lines to the Defense Waste Processing Facility. This report focuses on the aqueous phase chemistry of boric acid under conditions relevant to MCU and SWPF. Operating and transfer conditions examined for the purpose of this review include temperatures between 13 C (McLeskey, 2008) and 45 C (Fondeur, 2007) and concentrations from 0 to 3M in nitric acid as well as exposure of small amounts of entrained boric acid in the organic phase to the sodium hydroxide caustic wash stream. Experiments were also conducted to observe any chemical reactions and off-gas generation that could occur when 0.01 M boric acid solution mixes with 3 M nitric acid solution and vice versa. Based on the low concentration (0.01M) of boric acid in the MCU/SWPF strip acid and the moderate operating temperatures (13 C to 45 C), it is unlikely that crystallization of boric acid will occur in the acid strip solution under process or transfer conditions. Mixing experiments of boric and nitric acid show no measurable gas generation (< 1 cc of gas per liter of solution) under similar process conditions.

The Impact Of The Mcu Life Extension Solvent On Dwpf Glass Formulation Efforts

International Nuclear Information System (INIS)

Peeler, D.; Edwards, T.

2011-01-01

As a part of the Actinide Removal Process (ARP)/Modular Caustic Side Solvent Extraction Unit (MCU) Life Extension Project, a next generation solvent (NG-CSSX), a new strip acid, and modified monosodium titanate (mMST) will be deployed. The strip acid will be changed from dilute nitric acid to dilute boric acid (0.01 M). Because of these changes, experimental testing with the next generation solvent and mMST is required to determine the impact of these changes in 512-S operations as well as Chemical Process Cell (CPC), Defense Waste Processing Facility (DWPF) glass formulation activities, and melter operations at DWPF. To support programmatic objectives, the downstream impacts of the boric acid strip effluent (SE) to the glass formulation activities and melter operations are considered in this study. More specifically, the impacts of boric acid additions to the projected SB7b operating windows, potential impacts to frit production temperatures, and the potential impact of boron volatility are evaluated. Although various boric acid molarities have been reported and discussed, the baseline flowsheet used to support this assessment was 0.01M boric acid. The results of the paper study assessment indicate that Frit 418 and Frit 418-7D are robust to the implementation of the 0.01M boric acid SE into the SB7b flowsheet (sludge-only or ARP-added). More specifically, the projected operating windows for the nominal SB7b projections remain essentially constant (i.e., 25-43 or 25-44% waste loading (WL)) regardless of the flowsheet options (sludge-only, ARP added, and/or the presence of the new SE). These results indicate that even if SE is not transferred to the Sludge Receipt and Adjustment Tank (SRAT), there would be no need to add boric acid (from a trim tank) to compositionally compensate for the absence of the boric acid SE in either a sludge-only or ARP-added SB7b flowsheet. With respect to boron volatility, the Measurement Acceptability Region (MAR) assessments also

Solvent extraction of Zn and metals in Zn ores by nonphosphorous solvents

International Nuclear Information System (INIS)

Auchapt, J.M.; Tostain, Jacqueline.

1975-07-01

This bibliography follows a first work on Zn solvent extraction by organo-phosphorous compounds. The other solvents used in Zn extraction, are studied: oxygenated nonphosphorous solvents (ketones, alcohols, carboxylic acids, sulfonates), nitrogenous solvents and hydrocarbons [fr

Solvent substitution

International Nuclear Information System (INIS)

1990-01-01

The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general ''Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated

A Tetrahydrofuran-selective Optical Solvent Sensor Based on Solvatochromic Polydiacetylene

International Nuclear Information System (INIS)

Park, Dong-Hoon; Kim, Bubsung; Kim, Jong-Man

2016-01-01

Polydiacetylene (PDAs) have received great attention as colorimetric sensors since these conjugated polymers undergo a blue-to-red color change upon various chemical/biochemical and physical stimuli. PDAs have been reported to display thermochromism (heat), solvatochromism (solvent), mechanochromism (mechanical strain) as well as magnetochromism (magnetic force) electrochromism (electric current), and affinochromism (ligand-receptor interaction). The solvent induced color change of PDA is generally non-specific and irreversible. For instance, the PDA derived from 10,12-pentacosadiynoic acid (PCDA) undergoes a blue-to-red (or purple) color change upon exposure to many common organic solvents including tetrahydrofuran (THF), chloroform, dichloromethane, acetone, methanol (MeOH), ethyl acetate (EA), and diethyl ether. The results obtained from Raman spectral analysis suggests that exposure to THF causes the distortion of the backbone of the polymer main chain and some conformational changes in the aliphatic side chain. Solvatochromism of a PDA is closely related to the solubility of a diacetylene monomer. PDA undergoes a color change when the dissolution of unpolymerized monomers causes some void in the PDA supramolecules. Since PCDA-mBzA has a good solubility only in THF, colorimetric transition of PDA occurs only in response to THF. Since solubility of a diacetylene monomer can be manipulated by structural change of the monomer, we believe the strategy described in current investigation should be useful for the development of solvent-specific PDA sensor systems

A Tetrahydrofuran-selective Optical Solvent Sensor Based on Solvatochromic Polydiacetylene

Energy Technology Data Exchange (ETDEWEB)

Park, Dong-Hoon; Kim, Bubsung; Kim, Jong-Man [Hanyang University, Seoul (Korea, Republic of)

2016-06-15

Polydiacetylene (PDAs) have received great attention as colorimetric sensors since these conjugated polymers undergo a blue-to-red color change upon various chemical/biochemical and physical stimuli. PDAs have been reported to display thermochromism (heat), solvatochromism (solvent), mechanochromism (mechanical strain) as well as magnetochromism (magnetic force) electrochromism (electric current), and affinochromism (ligand-receptor interaction). The solvent induced color change of PDA is generally non-specific and irreversible. For instance, the PDA derived from 10,12-pentacosadiynoic acid (PCDA) undergoes a blue-to-red (or purple) color change upon exposure to many common organic solvents including tetrahydrofuran (THF), chloroform, dichloromethane, acetone, methanol (MeOH), ethyl acetate (EA), and diethyl ether. The results obtained from Raman spectral analysis suggests that exposure to THF causes the distortion of the backbone of the polymer main chain and some conformational changes in the aliphatic side chain. Solvatochromism of a PDA is closely related to the solubility of a diacetylene monomer. PDA undergoes a color change when the dissolution of unpolymerized monomers causes some void in the PDA supramolecules. Since PCDA-mBzA has a good solubility only in THF, colorimetric transition of PDA occurs only in response to THF. Since solubility of a diacetylene monomer can be manipulated by structural change of the monomer, we believe the strategy described in current investigation should be useful for the development of solvent-specific PDA sensor systems.

Solvent/Non-Solvent Sintering To Make Microsphere Scaffolds

Science.gov (United States)

Laurencin, Cato T.; Brown, Justin L.; Nair, Lakshmi

2011-01-01

A solvent/non-solvent sintering technique has been devised for joining polymeric microspheres to make porous matrices for use as drug-delivery devices or scaffolds that could be seeded with cells for growing tissues. Unlike traditional sintering at elevated temperature and pressure, this technique is practiced at room temperature and pressure and, therefore, does not cause thermal degradation of any drug, protein, or other biochemical with which the microspheres might be loaded to impart properties desired in a specific application. Also, properties of scaffolds made by this technique are more reproducible than are properties of comparable scaffolds made by traditional sintering. The technique involves the use of two miscible organic liquids: one that is and one that is not a solvent for the affected polymer. The polymeric microspheres are placed in a mold having the size and shape of the desired scaffold, then the solvent/non-solvent mixture is poured into the mold to fill the void volume between the microspheres, then the liquid mixture is allowed to evaporate. Some of the properties of the resulting scaffold can be tailored through choice of the proportions of the liquids and the diameter of the microspheres.

Solvent substitution

Energy Technology Data Exchange (ETDEWEB)

1990-01-01

The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated.

Solvents and solvent effects in organic chemistry

National Research Council Canada - National Science Library

Reichardt, C; Welton, T

2011-01-01

.../guest complexation equilibria and reactions in biphasic solvent systems and neoteric solvents, respectively. More than 900 new references have been added, giving preference to review articles, and many older ones have been deleted. New references either replace older ones or are added to the end of the respective reference list of each chapter. Th...

Crud handling circuit

International Nuclear Information System (INIS)

Smith, J.C.; Manuel, R.J.; McAllister, J.E.

1981-01-01

A process for handling the problems of crud formation during the solvent extraction of wet-process phosphoric acid, e.g. for uranium and rare earth removal, is described. It involves clarification of the crud-solvent mixture, settling, water washing the residue and treatment of the crud with a caustic wash to remove and regenerate the solvent. Applicable to synergistic mixtures of dialkylphosphoric acids and trialkylphosphine oxides dissolved in inert diluents and more preferably to the reductive stripping technique. (U.K.)

Combined Extraction of Cesium, Strontium, and Actinides from Alkaline Media: An Extension of the Caustic-Side Solvent Extraction (CSSX) Process Technology

International Nuclear Information System (INIS)

Kenneth Raymond

2004-01-01

The wastes present at DOE long-term storage sites are usually highly alkaline, and because of this, much of the actinides in these wastes are in the sludge phase. Enough actinide materials still remain in the supernatant liquid that they require separation followed by long-term storage in a geological repository. The removal of these metals from the liquid waste stream would permit their disposal as low-level waste and dramatically reduce the volume of high-level wastes

The chemistry of nonaqueous solvents v.4 solution phenomena and aprotic solvents

CERN Document Server

Lagowski, J J

1976-01-01

The Chemistry of Nonaqueous Solvents, Volume IV: Solution Phenomena and Aprotic Solvents focuses on the chemistry of nonaqueous solvents, with emphasis on solution phenomena and aprotic solvents such as tetramethylurea, inorganic acid chlorides, cyclic carbonates, and sulfolane. This book is organized into seven chapters and begins with an overview of the theory of electrical conductivity and elementary experimental considerations, along with some of the interesting research on nonaqueous solvents. It then turns to a discussion on hydrogen bonding phenomena in nonaqueous systems as probed

Separation of technetium from nuclear waste stream simulants. Final report

International Nuclear Information System (INIS)

Strauss, S.H.

1995-01-01

The author studied liquid anion exchangers, such as Aliquat-336 nitrate, various pyridinium nitrates, and related salts, so that they may be applied toward a specific process for extracting (partitioning) and recovering 99 TcO 4 - from nuclear waste streams. Many of the waste streams are caustic and contain a variety of other ions. For this reason, the author studied waste stream simulants that are caustic and contain appropriate concentrations of selected, relevant ions. Methods of measuring the performance of the exchangers and extractant systems included contact experiments. Batch contact experiments were used to determine the forward and reverse extraction parameters as a function of temperature, contact time, phase ratio, concentration, solvent (diluent), and other physical properties. They were also used for stability and competition studies. Specifically, the author investigated the solvent extraction behavior of salts of perrhenate (ReO 4 - ), a stable (non-radioactive) chemical surrogate for 99 TcO 4 - . Results are discussed for alternate organic solvents; metalloporphyrins, ferrocenes, and N-cetyl pyridium nitrate as alternate extractant salts; electroactive polymers; and recovery of ReO 4 - and TcO 4 -

Analytical results from salt batch 9 routine DSSHT and SEHT monthly samples

Energy Technology Data Exchange (ETDEWEB)

Peters, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-06-01

Strip Effluent Hold Tank (SEHT) and Decontaminated Salt Solution Hold Tank (DSSHT) samples from several of the “microbatches” of Integrated Salt Disposition Project (ISDP) Salt Batch (“Macrobatch”) 9 have been analyzed for ²³⁸Pu, ⁹⁰Sr, ¹³⁷Cs, cations (Inductively Coupled Plasma Emission Spectroscopy - ICPES), and anions (Ion Chromatography Anions - IC-A). The analytical results from the current microbatch samples are similar to those from previous macrobatch samples. The Cs removal continues to be acceptable, with decontamination factors (DF) averaging 25700 (107% RSD). The bulk chemistry of the DSSHT and SEHT samples do not show any signs of unusual behavior, other than lacking the anticipated degree of dilution that is calculated to occur during Modular Caustic-Side Solvent Extraction Unit (MCU) processing.

Synthesis of ZnS thin films from aqueous caustic of trisodium citrate and their properties

Directory of Open Access Journals (Sweden)

Martyn A. Sozanskyi

2015-12-01

Full Text Available Zinc sulfide (ZnS thin films due to their properties are widely used in various electronic optical devices. They are produced by several methods, among which – vacuum sublimation, high frequency sputtering method, quasiclosed volume method, sol-gel method, electrodeposition. These methods have high energy consumption which increases the price of ZnS thin films. Aim: The aim of this work is to establish the optimal parameters of the synthesis of ZnS thin films of the aqueous caustic and the correlation between content of zinc in the synthesized films determined by the method of stripping voltammetry and thickness, structural, morphological and optical parameters. Materials and Methods: The ZnS thin films were obtained from aqueous caustics of zinc-containing salt using chemical deposition. Fresh solution of zinc-containing salt, trisodium citrate (Na3C6H5O7 as a complexing agent, thiourea ((NH22CS and ammonium hydroxide (NH4OH was used for the synthesis of ZnS films by chemical deposition. The deposition was performed on prepared glass substrates with the area of 5,76 cm2. Results: The phase mixture of the films has been determined. It showed the presence of ZnS compounds in the cubic modification (sphalerite. Stripping voltammetry was used to determine the mass of zinc in the ZnS films on various conditions of synthesis, namely on the concentration of the initial zinc-containing salt, trisodium citrate, thiourea, deposition time and temperature. The surface morphology, optical properties, the thickness of the ZnS resulting films have been studied. Conclusions: The optimal conditions for the synthesis of ZnS films were found based on these data. Three-dimensional surface morphology of ZnS film studies showed its smoothness, uniformity, integrity and confirmed the correctness of determining the optimal synthesis parameters.

TROSY of side-chain amides in large proteins

Science.gov (United States)

Liu, Aizhuo; Yao, Lishan; Li, Yue; Yan, Honggao

2012-01-01

By using the mixed solvent of 50% H2O/50% D2O and employing deuterium decoupling, TROSY experiments exclusively detect NMR signals from semideuterated isotopomers of carboxamide groups with high sensitivities for proteins with molecular weights up to 80 kDa. This isotopomer-selective strategy extends TROSY experiments from exclusively detecting backbone to both backbone and side-chain amides, particularly in large proteins. Because of differences in both TROSY effect and dynamics between 15N–HE{DZ} and 15N–HZ{DE} isotopomers of the same carboxamide, the 15N transverse magnetization of the latter relaxes significantly faster than that of the former, which provides a direct and reliable stereospecific distinction between the two configurations. The TROSY effects on the 15N–HE{DZ} isotopomers of side-chain amides are as significant as on backbone amides. PMID:17347000

A solvent/non-solvent system for achieving solution-processed multilayer organic light-emitting devices

Energy Technology Data Exchange (ETDEWEB)

Yu, Yue; Wu, Zhaoxin, E-mail: zhaoxinwu@mail.xjtu.edu.cn; He, Lin; Jiao, Bo; Hou, Xun

2015-08-31

We developed a solvent/non-solvent system to fabricate the multilayer organic light-emitting devices (OLEDs) based on poly(N-vinylcarbazole) (PVK) by solution-process. This solvent system consists of both the solvent and non-solvent of PVK, in which fluorescent small molecules could be fully dissolved and directly spin-coated on top of the PVK layer; it could effectively avoid the redissolution of PVK during the spin-coating process of small molecules emitting layer. In the further investigation of this system, we also demonstrated the three-component solvent system, and found out that the third component, a less volatile solvent of PVK, was crucial for preparing a smoother interface between PVK and emitting layer. Compared with OLEDs through the vacuum deposition, the devices fabricated by solution-process from the solvent/non-solvent system showed comparable efficiency, which indicate that the solvent/non-solvent system can be used as an alternative process to prepare the polymer and small molecule multilayer devices through all-solution-process. - Highlights: • We fabricate the multilayer OLEDs by solution-process using a novel system. • We develop a solvent/non-solvent system of polymer (PVK) to avoid redissolution. • Small molecules could be fully dissolved and directly spin-coated on PVK layer. • The devices fabricated by the system and vacuum deposition show comparable efficiency.

INVESTIGATION INTO THE RATE OF TRIOCTYLAMINE PARTITIONING INTO THE MCU AQUEOUS PHASES

Energy Technology Data Exchange (ETDEWEB)

Peters, T.; Couture, A.

2013-07-16

The Savannah River National Laboratory (SRNL) has examined the issue of trioctylamine (TOA) losses at the Modular Caustic-Side Solvent Extraction Unit (MCU) solvent. For this study, SRNL used partitioning and radiolysis data from the Oak Ridge National Laboratory (ORNL) as well as actual MCU operational data. From the radiolysis data, SRNL prepared a model on the rate of TOA degradation. From the combined sets of data, SRNL has calculated the largest possible value of TOA (although this value is not credible) in the Strip Effluent (SE) and also calculated two different conservative, more realistic values for TOA in the SE. Even under conservative assumptions, such as all of the TOA losses partitioning solely into the Strip Effluent (SE), the MCU operational data suggests that the maximum realistic TOA concentration in the SE is < 0.6 mg/L. Furthermore, from understanding the chemical differences between the old and new strip solutions, SRNL does not believe that the TOA will deplete from the blended BOBCalixC6 – Next Generation Solvent (NGS-MCU) at a rate higher than previously experienced. Finally, SRNL recommends pursuing analytical development of a method for TOA with a superior precision compared to the current method. However, as the TOA in the blended solvent will continuously decline during MCU operations, further improvements in the development of the understanding of TOA losses may not be cost effective.

Method of conversion of caustic liquid radioactive wastes containing sodium nitrates into solid insoluble products

International Nuclear Information System (INIS)

Barney, G.S.; Brownell, L.E.

1975-01-01

A proposal is made to convert caustic, liquid, radioactive wastes containing sodium nitrate into a solid product by reaction with powdered aluminium silicate at temperatures between 30 0 and 100 0 C, which is practically insoluble (10 -7 to 10 -10 g/cm 2 -day) and is thermally stable. A cancrinite is formed which binds the radioactive salts in the cage-like structure of its crystal lattice. The method is also suitable for liquid wastes from the Purex method as well as for wastes containing fission products of Cs 137 and Sr 90 in concentrations of 0.37 M to 0.01 M. Numerous detailed examples explain the invention. (UW/LH) [de

INVESTIGATION OF THE POTENTIAL FOR CAUSTIC STRESS CORROSION CRACKING OF A537 CARBON STEEL NUCLEAR WASTE TANKS

International Nuclear Information System (INIS)

Lam, P.

2009-01-01

The evaporator recycle streams contain waste in a chemistry and temperature regime that may be outside of the current waste tank corrosion control program, which imposes temperature limits to mitigate caustic stress corrosion cracking (CSCC). A review of the recent service history (1998-2008) of Tanks 30 and 32 showed that these tanks were operated in highly concentrated hydroxide solution at high temperature. Visual inspections, experimental testing, and a review of the tank service history have shown that CSCC has occurred in uncooled/un-stress relieved F-Area tanks. Therefore, for the Type III/IIIA waste tanks the efficacy of the stress relief of welding residual stress is the only corrosion-limiting mechanism. The objective of this experimental program is to test carbon steel small scale welded U-bend specimens and large welded plates (12 x 12 x 1 in.) in a caustic solution with upper bound chemistry (12 M hydroxide and 1 M each of nitrate, nitrite, and aluminate) and temperature (125 C). These conditions simulate worst-case situations in Tanks 30 and 32. Both as-welded and stress-relieved specimens have been tested. No evidence of stress corrosion cracking was found in the U-bend specimens after 21 days of testing. The large plate test is currently in progress, but no cracking has been observed after 9 weeks of immersion. Based on the preliminary results, it appears that the environmental conditions of the tests are unable to develop stress corrosion cracking within the duration of these tests

DEVELOPMENT OF A KINETIC MODEL OF BOEHMITE DISSOLUTION IN CAUSTIC SOLUTIONS APPLIED TO OPTIMIZE HANFORD WASTE PROCESSING

International Nuclear Information System (INIS)

Disselkamp, R.S.

2011-01-01

Boehmite (e.g., aluminum oxyhydroxide) is a major non-radioactive component in Hanford and Savannah River nuclear tank waste sludge. Boehmite dissolution from sludge using caustic at elevated temperatures is being planned at Hanford to minimize the mass of material disposed of as high-level waste (HLW) during operation of the Waste Treatment Plant (WTP). To more thoroughly understand the chemistry of this dissolution process, we have developed an empirical kinetic model for aluminate production due to boehmite dissolution. Application of this model to Hanford tank wastes would allow predictability and optimization of the caustic leaching of aluminum solids, potentially yielding significant improvements to overall processing time, disposal cost, and schedule. This report presents an empirical kinetic model that can be used to estimate the aluminate production from the leaching of boehmite in Hanford waste as a function of the following parameters: (1) hydroxide concentration; (2) temperature; (3) specific surface area of boehmite; (4) initial soluble aluminate plus gibbsite present in waste; (5) concentration of boehmite in the waste; and (6) (pre-fit) Arrhenius kinetic parameters. The model was fit to laboratory, non-radioactive (e.g. 'simulant boehmite') leaching results, providing best-fit values of the Arrhenius A-factor, A, and apparent activation energy, E A , of A = 5.0 x 10 12 hour -1 and E A = 90 kJ/mole. These parameters were then used to predict boehmite leaching behavior observed in previously reported actual waste leaching studies. Acceptable aluminate versus leaching time profiles were predicted for waste leaching data from both Hanford and Savannah River site studies.

Methods of producing adsorption media including a metal oxide

Science.gov (United States)

Mann, Nicholas R; Tranter, Troy J

2014-03-04

Methods of producing a metal oxide are disclosed. The method comprises dissolving a metal salt in a reaction solvent to form a metal salt/reaction solvent solution. The metal salt is converted to a metal oxide and a caustic solution is added to the metal oxide/reaction solvent solution to adjust the pH of the metal oxide/reaction solvent solution to less than approximately 7.0. The metal oxide is precipitated and recovered. A method of producing adsorption media including the metal oxide is also disclosed, as is a precursor of an active component including particles of a metal oxide.

Analysis of solvent extracts from coal liquefaction in a flowing solvent reactor

Energy Technology Data Exchange (ETDEWEB)

Li, Wen-Ying; Feng, Jie; Xie, Ke-Chang [Key Laboratory of Coal Science and Technology, Taiyuan University of Technology, Ministry of Education and Shanxi Province, No. 79 Yingze West Street, Taiyuan 030024 (China); Kandiyoti, R. [Department of Chemical Engineering and Chemical Technology, Imperial College, University of London, London SW7 2BY (United Kingdom)

2004-10-15

Point of Ayr coal has been extracted using three solvents, tetralin, quinoline and 1-methyl-2-pyrrolidinone (NMP) at two temperatures 350 and 450 C, corresponding approximately to before and after the onset of massive covalent bond scission by pyrolysis. The three solvents differ in solvent power and the ability to donate hydrogen atoms to stabilise free radicals produced by pyrolysis of the coal. The extracts were prepared in a flowing solvent reactor to minimise secondary thermal degradation of the primary extracts. Analysis of the pentane-insoluble fractions of the extracts was achieved by size exclusion chromatography, UV-fluorescence spectroscopy in NMP solvent and probe mass. With increasing extraction temperature, the ratio of the amount having big molecular weight to that having small molecular weight in tetralin extracts was increased; the tetralin extract yield increased from 12.8% to 75.9%; in quinoline, increasing extraction temperature did not have an effect on the molecular weight of products but there was a big increase in extract yield. The extracts in NMP showed the enhanced solvent extraction power at both temperatures, with a shift in the ratio of larger molecules to smaller molecules with increasing extraction temperature and with the highest conversion of Point of Ayr coal among these three solvents at both temperatures. Solvent adducts were detected in the tetralin and quinoline extracts by probe mass spectrometry; solvent products were formed from NMP at both temperatures.

The use tri-n-butyl phosphate in plutonium extraction. Radiolysis and recycling of the solvent (1963); Le phosphate de tri-n-butyle dans l'extraction du plutonium. Radiolyse et recyclage du solvant (1963)

Energy Technology Data Exchange (ETDEWEB)

Isaac, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

The work concerns the radiolysis and recycling of tri-n-butyl phosphate used as extraction solvent for plutonium. The radiolysis is studied on an industrial solvent using a cobalt 60 source. Figures are given for the yield of the mono- and di-butyl-phosphoric acids formed from the dry and water-saturated solvents and the influence of nitric acid on the formation of dibutyl-phosphoric acid is indicated. The recycling treatment of the solvent is reconsidered with a view to lowering the residual contamination due to fission products. The tests carried out on a solvent from the plutonium extraction plant at Marcoule show the efficiency of the sodium carbonate treatment. Of all the products studied, only caustic soda led to a better decontamination than sodium carbonate; in all cases however, the elimination of ruthenium is always incomplete. (author) [French] L'etude porte sur la radiolyse et le recyclage du phosphate de tri-n-butyle utilise comme solvant d'extraction du plutonium. La radiolyse est etudiee sur un solvant industriel a l'aide d'une source de cobalt 60. On donne les rendements de formation des acides mono- et dlbutylphosphoriques a partir de solvants secs et satures d'eau, et on montre l'influence de l'acide nitrique sur la formation de l'acide dibutylphosphorique. Le traitement de recyclage du solvant est repris en vue d'abaisser la contamination residuelle en produits de fission. Les essais, effectues sur un solvant provenant de l'usine d'extraction du plutonium de Marcoule, montrent l'efficacite du traitement au carbonate de sodium. De tous les reactifs etudies, seule la soude a donne une decontamination superieure au carbonate de sodium; mais dans tous les cas, l'elimination du ruthenium est toujours incomplete. (auteur)

The Solvent Selection framework: solvents for organic synthesis, separation processes and ionic-organic synthesis

DEFF Research Database (Denmark)

Mitrofanov, Igor; Sansonetti, Sascha; Abildskov, Jens

2012-01-01

This paper presents a systematic integrated framework for solvent selection and solvent design. The framework is divided into several modules, which can tackle specific problems in various solvent-based applications. In particular, three modules corresponding to the following solvent selection pr...

Solvent effects in the synergistic solvent extraction of Co2+

International Nuclear Information System (INIS)

Kandil, A.T.; Ramadan, A.

1979-01-01

The extraction of Co 2+ from a 0.1M ionic strength aqueous phase (Na + , CH 3 COOH) of pH = 5.1 was studied using thenoyltrifluoroacetone, HTTA, in eight different solvents and HTTA + trioctylphosphine oxide, TOPO, in the same solvents. A comparison of the effect of solvent dielectric constant on the equilibrium constant shows a synergism as a result of the increased hydrophobic character imparted to the metal complex due to the formation of the TOPO adduct. (author)

Hydrophilic actinide complexation studied by solvent extraction radiotracer technique

International Nuclear Information System (INIS)

Rydberg, J.

1996-10-01

Actinide migration in the ground water is enhanced by the formation of water soluble complexes. It is essential to the risk analysis of a wet repository to know the concentration of central atoms and the ligands in the ground water, and the stability of complexes formed between them. Because the chemical behavior at trace concentrations often differ from that at macro concentrations, it is important to know the chemical behavior of actinides at trace concentrations in ground water. One method used for such investigations is the solvent extraction radiotracer (SXRT) technique. This report describes the SXRT technique in some detail. A particular reason for this analysis is the claim that complex formation constants obtained by SXRT are less reliable than results obtained by other techniques. It is true that several difficulties are encountered in the application of SXRT technique to actinide solution, such as redox instability, hydrophilic complexation by side reactions and sorption, but it is also shown that a careful application of the SXRT technique yields results as reliable as by any other technique. The report contains a literature survey on solvent extraction studies of actinide complexes formed in aqueous solutions, particularly by using the organic reagent thenoyltrifluoroacetone (TTA) dissolved in benzene or chloroform. Hydrolysis constants obtained by solvent extraction are listed as well as all actinide complexes studied by SX with inorganic and organic ligands. 116 refs, 11 tabs

Hydrophilic actinide complexation studied by solvent extraction radiotracer technique

Energy Technology Data Exchange (ETDEWEB)

Rydberg, J [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Nuclear Chemistry and Radiochemistry Consultant Group, Vaestra Froelunda (Sweden)

1996-10-01

Actinide migration in the ground water is enhanced by the formation of water soluble complexes. It is essential to the risk analysis of a wet repository to know the concentration of central atoms and the ligands in the ground water, and the stability of complexes formed between them. Because the chemical behavior at trace concentrations often differ from that at macro concentrations, it is important to know the chemical behavior of actinides at trace concentrations in ground water. One method used for such investigations is the solvent extraction radiotracer (SXRT) technique. This report describes the SXRT technique in some detail. A particular reason for this analysis is the claim that complex formation constants obtained by SXRT are less reliable than results obtained by other techniques. It is true that several difficulties are encountered in the application of SXRT technique to actinide solution, such as redox instability, hydrophilic complexation by side reactions and sorption, but it is also shown that a careful application of the SXRT technique yields results as reliable as by any other technique. The report contains a literature survey on solvent extraction studies of actinide complexes formed in aqueous solutions, particularly by using the organic reagent thenoyltrifluoroacetone (TTA) dissolved in benzene or chloroform. Hydrolysis constants obtained by solvent extraction are listed as well as all actinide complexes studied by SX with inorganic and organic ligands. 116 refs, 11 tabs.

An overview of industrial solvent use or is there life after chlorinated solvents?

International Nuclear Information System (INIS)

Green, B.

1991-01-01

Everyone using industrial chemicals has been affected by the fire- storm of new regulations governing solvent use. How will companies currently using hazardous solvents prepare for the changes ahead? What will the impact be on commonly used industrial solvents? What effect are environmental pressures having on solvent use and disposal? Are the responsible individuals in your company up-to-date on phase-out schedules? This paper is written for an audience of compliance coordinators, consultants, production engineers and corporate management. In it, the either addresses the above questions and discusses the specific products affected. The author reviews currently available alternatives to chlorinated and hazardous solvents and introduces a simple system for rating alternatives. The program also includes a discussion of solvent minimization programs and worker reeducation

Crystal habit prediction - Including the liquid as well as the solid side

Energy Technology Data Exchange (ETDEWEB)

Schmidt, C.; Ulrich, J. [Martin-Luther-Universitaet Halle-Wittenberg, Zentrum fuer Ingenieurwissenschaften, Verfahrenstechnik/ TVT, 06099 Halle (Saale) (Germany)

2012-06-15

Commercially available methods of morphology prediction utilize molecular dynamics to estimate the crystal growth rates but predominantly consider the solid side. For the extension of these methods to a multi-component solid-liquid system the diffusion coefficient is required. Since, the diffusion coefficient enables the calculation of crystal growth rates and the morphology in presence of additives and solvents. Modeling the diffusion coefficient is achieved by conducting MD on a system consisting of the crystal surface and the liquid phase. The achieved results match very well with the calculated diffusion coefficient (Wilke-Chang). In this case study benzoic acid is used as model substance with water as solvent. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

A hierarchy of functionally important relaxations within myoglobin based on solvent effects, mutations and kinetic model.

Science.gov (United States)

Dantsker, David; Samuni, Uri; Friedman, Joel M; Agmon, Noam

2005-06-01

Geminate CO rebinding in myoglobin is studied for two viscous solvents, trehalose and sol-gel (bathed in 100% glycerol) at several temperatures. Mutations in key distal hemepocket residues are used to eliminate or enhance specific relaxation modes. The time-resolved data are analyzed with a modified Agmon-Hopfield model which is capable of providing excellent fits in cases where a single relaxation mode is dominant. Using this approach, we determine the relaxation rate constants of specific functionally important modes, obtaining also their Arrhenius activation energies. We find a hierarchy of distal pocket modes controlling the rebinding kinetics. The "heme access mode" (HAM) is responsible for the major slow-down in rebinding. It is a solvent-coupled cooperative mode which restricts ligand return from the xenon cavities. Bulky side-chains, like those His64 and Trp29 (in the L29W mutant), operate like overdamped pendulums which move over and block the binding site. They may be either unslaved (His64) or moderately slaved (Trp29) to the solvent. Small side-chain relaxations, most notably of leucines, are revealed in some mutants (V68L, V68A). They are conjectured to facilitate inter-cavity ligand motion. When all relaxations are arrested (H64L in trehalose), we observe pure inhomogeneous kinetics with no temperature dependence, suggesting that proximal relaxation is not a factor on the investigated timescale.

Carbon Nanotube Dispersion in Solvents and Polymer Solutions: Mechanisms, Assembly, and Preferences.

Science.gov (United States)

Pramanik, Chandrani; Gissinger, Jacob R; Kumar, Satish; Heinz, Hendrik

2017-12-26

Debundling and dispersion of carbon nanotubes (CNTs) in polymer solutions play a major role in the preparation of carbon nanofibers due to early effects on interfacial ordering and mechanical properties. A roadblock toward ultrastrong fibers is the difficulty to achieve homogeneous dispersions of CNTs in polyacrylonitrile (PAN) and poly(methyl methacrylate) (PMMA) precursor solutions in solvents such as dimethyl sulfoxide (DMSO), N,N-dimethylacetamide (DMAc), and N,N-dimethylformamide (DMF). In this contribution, molecular dynamics simulations with accurate interatomic potentials for graphitic materials that include virtual π electrons are reported to analyze the interaction of pristine single wall CNTs with the solvents and polymer solutions at 25 °C. The results explain the barriers toward dispersion of SWCNTs and quantify CNT-solvent, polymer-solvent, as well as CNT-polymer interactions in atomic detail. Debundling of CNTs is overall endothermic and unfavorable with dispersion energies of +20 to +30 mJ/m 2 in the pure solvents, + 20 to +40 mJ/m 2 in PAN solutions, and +20 to +60 mJ/m 2 in PMMA solutions. Differences arise due to molecular geometry, polar, van der Waals, and CH-π interactions. Among the pure solvents, DMF restricts CNT dispersion less due to the planar geometry and stronger van der Waals interactions. PAN and PMMA interact favorably with the pure solvents with dissolution energies of -0.7 to -1.1 kcal per mole monomer and -1.5 to -2.2 kcal per mole monomer, respectively. Adsorption of PMMA onto CNTs is stronger than that of PAN in all solvents as the molecular geometry enables more van der Waals contacts between alkyl groups and the CNT surface. Polar side groups in both polymers prefer interactions with the polar solvents. Higher polymer concentrations in solution lead to polymer aggregation via alkyl groups and reduce adsorption onto CNTs. PAN and PMMA solutions in DMSO and dilute solutions in DMF support CNT dispersion more than other

Solvent - solute interaction

International Nuclear Information System (INIS)

Urbanczyk, A.; Kalinowski, M.K.

1983-01-01

The electronic absorption spectrum of vanadyl acetylacetonate has been studied in 15 organic solvents. It has been found that wavenumbers and molar absorptivities of the long-wavelength bands (d-d transitions) can be well described by a complementary Lewis acid-base model including Gutmann's donor number [Gutmann V., Wychera E., Inorg. Nucl. Chem. Letters 2, 257 (1966)] and acceptor number [Mayer U., Gutmann V., Gerger W., Monatsh. Chem. 106, 1235 (1975)] of a solvent. This model describes also the solvent effect of the hyperfine splitting constant, Asub(iso)( 51 V), from e.s.r. spectra of VOacac 2 . These observations are discussed in terms of the donor-acceptor concept for solvent-solute interactions. (Author)

Deasphalting solvents

International Nuclear Information System (INIS)

Carrillo, J. A; Caceres, J; Vela, G; Bueno, H

1996-01-01

This paper describes how the deasphalted oil (DMO) or demetalized oil (DMO) quality (CCR, Ni, V end asphaltenes contents) changes with: DAO or DMO yield, solvent/feed ratio, type of vacuum reside (from paraffinic to blends with vis breaking bottoms), extraction temperature and extraction solvent (propane, propylene, n-butane and I butane)

Solvent cleaning system and method for removing contaminants from solvent used in resin recycling

Science.gov (United States)

Bohnert, George W [Harrisonville, MO; Hand, Thomas E [Lee's Summit, MO; DeLaurentiis, Gary M [Jamestown, CA

2009-01-06

A two step solvent and carbon dioxide based system that produces essentially contaminant-free synthetic resin material and which further includes a solvent cleaning system for periodically removing the contaminants from the solvent so that the solvent can be reused and the contaminants can be collected and safely discarded in an environmentally safe manner.

Radiological pathways analysis for spent solvents from the boiler chemical cleaning at the Pickering Nuclear Site

International Nuclear Information System (INIS)

Garisto, N.C.; Eslami, Z.; Hodgins, S.; Beaman, T.; Von Svoboda, S.; Marczak, J.

2006-01-01

Spent solvents are generated as a result of Boiler Chemical Cleanings (BCC) at CANDU reactor sites. These solutions contain small amount of radioactivity from a number of different sources including: Cut tubes - short sections of boiler tubes are infrequently removed from the boilers for a detailed characterization. These tubes are typically only plugged at the tubesheet allowing the primary side deposits to be exposed to BCC solvents. Tube leaks - primary to secondary side leaks also occur infrequently as a result of tube degradation. Radioactivity from the leaking fluid can consequently be deposited in the sludge on the secondary side of the tubes. Diffusion of tritium - during normal operation of the reactor units, tritium slowly diffuses from the heavy water in the primary heat-transfer system to the light-water coolant on the secondary side. Some of this tritium is retained in the secondary side deposits. The Pickering Nuclear Generating Station (PNGS) would like the flexibility to have several options for handling the spent solvent waste and associated rinse water from BCC. To this end, a radiological pathways analysis was undertaken to determine dose consequences associated with each option. Sample results from this study are included in this paper. The pathways analysis is used in this study to calculate dose to hypothetical receptors including individuals such as truck drivers, incinerator workers, residue (ash) handlers, residents who live near the landfill, inadvertent intruders into the landfill after closure and residents who live near the outfall. This dose is compared to a de minimis dose. A de minimis dose or dose rate represents a level of risk, which is generally accepted as being of no significance. Shipments of spent solvents and rinse water with corresponding doses below de minimis can be sent to conventional (i.e., non-radioactive) landfills for incineration and disposal as the radioactive dose associated with them is much less than natural

Radiation stability of diglycolamide functionalized calix[4]arenes in ionic liquid: Solvent extraction, EPR and GC–MS studies

NARCIS (Netherlands)

Sengupta, A; Mohapatra, P.K.; Patil, A.B.; Kadam, R.M.; Verboom, Willem

2016-01-01

Ionic liquid-based solvent systems containing diglycolamide-functionalized calix[4]arenes (C4DGAs) are efficient for actinide ion extraction from nitric acid feeds. Therefore, the radiolytic stability of three C4DGAs (wide-rim, narrow-rim and both side DGA-functionalized calix[4]arenes) and TODGA

Microwave-Assisted Sample Treatment in a Fully Automated Flow-Based Instrument: Oxidation of Reduced Technetium Species in the Analysis of Total Technetium-99 in Caustic Aged Nuclear Waste Samples

International Nuclear Information System (INIS)

Egorov, Oleg B.; O'Hara, Matthew J.; Grate, Jay W.

2004-01-01

An automated flow-based instrument for microwave-assisted treatment of liquid samples has been developed and characterized. The instrument utilizes a flow-through reaction vessel design that facilitates the addition of multiple reagents during sample treatment, removal of the gaseous reaction products, and enables quantitative removal of liquids from the reaction vessel for carryover-free operations. Matrix modification and speciation control chemistries that are required for the radiochemical determination of total 99Tc in caustic aged nuclear waste samples have been investigated. A rapid and quantitative oxidation procedure using peroxydisulfate in acidic solution was developed to convert reduced technetium species to pertechnetate in samples with high content of reducing organics. The effectiveness of the automated sample treatment procedures has been validated in the radiochemical analysis of total 99Tc in caustic aged nuclear waste matrixes from the Hanford site

Tanks Focus Area Alternative Salt Processing Research and Development Program Plan

Energy Technology Data Exchange (ETDEWEB)

Harmon, Harry D.

2000-05-15

In March 2000, DOE-Headquarters (HQ) requested the Tanks Focus Area (TFA)to assume management responsibility for the Salt Processing Project technology development program at Savannah River Site. The TFA was requested to conduct several activities, including review and revision of the technology development roadmaps, development of down-selection criteria, and preparation of a comprehensive Research and Development (R&D) Program Plan for three candidate cesium removal technologies, as well as the Alpha and strontium removal processes that must also be carried out. The three cesium removal candidate technologies are Crystalline Silicotitanate (CST) Non-Elutable Ion Exchange, Caustic Side Solvent Extraction (CSSX), and Small Tank Tetraphenylborate Precipitation (STTP). This plan describes the technology development needs for each process that must be satisfied in order to reach a down-selection decision, as well as continuing technology development required to support conceptual design activities.

Tanks Focus Area Alternative Salt Processing Research and Development Program Plan

Energy Technology Data Exchange (ETDEWEB)

Harmon, Harry D.

2000-11-30

In March 2000, DOE-Headquarters (HQ) requested the Tanks Focus Area (TFA) to assume management responsibility for the Salt Processing Project technology development program at Savannah River Site. The TFA was requested to conduct several activities, including review and revision of the technology development roadmaps, development of down-selection criteria, and preparation of a comprehensive Research and Development (R&D) Program Plan for three candidate cesium removal technologies, as well as the Alpha and strontium removal processes that must also be carried out. The three cesium removal candidate technologies are Crystalline Silicotitanate (CST) Non-Elutable Ion Exchange, Caustic Side Solvent Extraction (CSSX), and Small Tank Tetraphenylborate Precipitation (STTP). This plan describes the technology development needs for each process that must be satisfied in order to reach a down-selection decision, as well as continuing technology development required to support conceptual design activities.

Caustic Injury In Adults – A Study For 3 Year Period

Directory of Open Access Journals (Sweden)

Radenkova-Saeva J.

2016-10-01

Full Text Available The aim of the study is to present the results of a 3-year clinico-epidemiological investigation of caustic injury in adults. The study includes 43 patients with acute corrosive ingestion, hospitalized in the Toxicology Clinic, University Hospital “N. I. Pirogov”, Sofia, Bulgaria, for the period 01.01. 2010-31.12.2012. The methods used include: clinical observation and examination, clinical laboratory, imaging, and psychiatric methods and tests. 43 patients between the ages of 22 and 82 with acute corrosive ingestions have been observed. Eleven were male (25.6% and 32 female (74.4%. All ingestions were intentional. Alkaline agents were used by all of the patients. The severity of poisonings varied from moderate to extremely severe. Different complications were seen in 82% of the cases - severe bleeding, perforation, fistula or/and stricture formation. Two of the patients have undergone surgical intervention - coloesophagoplastic - and have recovered completely. The motivation in different age groups was also studied. Psychiatric comorbidity occurred in patients as depressive and schizoaffective disorder, as well as existential crises. Acute corrosive ingestions by alkaline agents cause severe pathology. The severity and complex character of the injuries require good coordination between different medical specialists.

Probe of Multielectron Dynamics in Xenon by Caustics in High-Order Harmonic Generation

Science.gov (United States)

Faccialà, D.; Pabst, S.; Bruner, B. D.; Ciriolo, A. G.; De Silvestri, S.; Devetta, M.; Negro, M.; Soifer, H.; Stagira, S.; Dudovich, N.; Vozzi, C.

2016-08-01

We investigated the giant resonance in xenon by high-order harmonic generation spectroscopy driven by a two-color field. The addition of a nonperturbative second harmonic component parallel to the driving field breaks the symmetry between neighboring subcycles resulting in the appearance of spectral caustics at two distinct cutoff energies. By controlling the phase delay between the two color components it is possible to tailor the harmonic emission in order to amplify and isolate the spectral feature of interest. In this Letter we demonstrate how this control scheme can be used to investigate the role of electron correlations that give birth to the giant resonance in xenon. The collective excitations of the giant dipole resonance in xenon combined with the spectral manipulation associated with the two-color driving field allow us to see features that are normally not accessible and to obtain a good agreement between the experimental results and the theoretical predictions.

Separation of technetium from nuclear waste stream simulants. Final report

Energy Technology Data Exchange (ETDEWEB)

Strauss, S.H. [Colorado State Univ., Fort Collins, CO (United States). Dept. of Chemistry

1995-09-11

The author studied liquid anion exchangers, such as Aliquat-336 nitrate, various pyridinium nitrates, and related salts, so that they may be applied toward a specific process for extracting (partitioning) and recovering {sup 99}TcO{sub 4}{sup {minus}} from nuclear waste streams. Many of the waste streams are caustic and contain a variety of other ions. For this reason, the author studied waste stream simulants that are caustic and contain appropriate concentrations of selected, relevant ions. Methods of measuring the performance of the exchangers and extractant systems included contact experiments. Batch contact experiments were used to determine the forward and reverse extraction parameters as a function of temperature, contact time, phase ratio, concentration, solvent (diluent), and other physical properties. They were also used for stability and competition studies. Specifically, the author investigated the solvent extraction behavior of salts of perrhenate (ReO{sub 4}{sup {minus}}), a stable (non-radioactive) chemical surrogate for {sup 99}TcO{sub 4}{sup {minus}}. Results are discussed for alternate organic solvents; metalloporphyrins, ferrocenes, and N-cetyl pyridium nitrate as alternate extractant salts; electroactive polymers; and recovery of ReO{sub 4}{sup {minus}} and TcO{sub 4}{sup {minus}}.

Porous fiber formation in polymer-solvent system undergoing solvent evaporation

Science.gov (United States)

Dayal, Pratyush; Kyu, Thein

2006-08-01

Temporal evolution of the fiber morphology during dry spinning has been investigated in the framework of Cahn-Hilliard equation [J. Chem. Phys. 28, 258 (1958)] pertaining to the concentration order parameter or volume fraction given by the Flory-Huggins free energy of mixing [P. J. Flory, Principles of Polymer Chemistry (Cornell University Press, Ithaca, NY, 1953), p. 672] in conjunction with the solvent evaporation rate. To guide the solvent evaporation induced phase separation, equilibrium phase diagram of the starting polymer solution was established on the basis of the Flory-Huggins free energy of mixing. The quasi-steady-state approximation has been adopted to account for the nonconserved nature of the concentration field caused by the solvent loss. The process of solvent evaporation across the fiber skin-air interface was treated in accordance with the classical Fick's law [R. B. Bird et al., Transport Phenomena (J. Wiley, New York, 1960), p. 780]. The simulated morphologies include gradient type, hollow fiber type, bicontinuous type, and host-guest type. The development of these diverse fiber morphologies is explicable in terms of the phase diagram of the polymer solution in a manner dependent on the competition between the phase separation dynamics and rate of solvent evaporation.

Essential roles of protein-solvent many-body correlation in solvent-entropy effect on protein folding and denaturation: Comparison between hard-sphere solvent and water

International Nuclear Information System (INIS)

Oshima, Hiraku; Kinoshita, Masahiro

2015-01-01

In earlier works, we showed that the entropic effect originating from the translational displacement of water molecules plays the pivotal role in protein folding and denaturation. The two different solvent models, hard-sphere solvent and model water, were employed in theoretical methods wherein the entropic effect was treated as an essential factor. However, there were similarities and differences in the results obtained from the two solvent models. In the present work, to unveil the physical origins of the similarities and differences, we simultaneously consider structural transition, cold denaturation, and pressure denaturation for the same protein by employing the two solvent models and considering three different thermodynamic states for each solvent model. The solvent-entropy change upon protein folding/unfolding is decomposed into the protein-solvent pair (PA) and many-body (MB) correlation components using the integral equation theories. Each component is further decomposed into the excluded-volume (EV) and solvent-accessible surface (SAS) terms by applying the morphometric approach. The four physically insightful constituents, (PA, EV), (PA, SAS), (MB, EV), and (MB, SAS), are thus obtained. Moreover, (MB, SAS) is discussed by dividing it into two factors. This all-inclusive investigation leads to the following results: (1) the protein-water many-body correlation always plays critical roles in a variety of folding/unfolding processes; (2) the hard-sphere solvent model fails when it does not correctly reproduce the protein-water many-body correlation; (3) the hard-sphere solvent model becomes problematic when the dependence of the many-body correlation on the solvent number density and temperature is essential: it is not quite suited to studies on cold and pressure denaturating of a protein; (4) when the temperature and solvent number density are limited to the ambient values, the hard-sphere solvent model is usually successful; and (5) even at the ambient

Influence of temperature and solvent concentration on the kinetics of the enzyme carbonic anhydrase in carbon capture technology

DEFF Research Database (Denmark)

Gladis, Arne; Deslauriers, Maria Gundersen; Fosbøl, Philip Loldrup

2017-01-01

In this study the effect of carbonic anhydrase addition on the absorption of CO2 was investigated in a wetted wall column apparatus. Four different solvents: the primary amine monoethanolamine (MEA), the sterically hindered primary amine 2-amino-2-methyl-1-propanol (AMP), the tertiary amine N......-methyl-diethanolamine (MDEA) and the carbonate salt solution K2CO3 were compared in concentrations from 5 to 50 wt% in a temperature range of 298–328 K with and without enzyme. Necessary mass transfer parameters such as liquid side mass transfer coefficient and solvent and enzyme reaction rates were determined...

Restoring solvent for nuclear separation processes

International Nuclear Information System (INIS)

Reif, D.J.

1987-01-01

Solvent extraction separation processes are used to recover usable nuclear materials from spent fuels. These processes involve the use of an extractant/diluent (solvent) for separation of the reusable actinides from unwanted fission products. The most widely used processes employ tributyl phosphate as an extractant diluted with a normal-paraffin hydrocarbon. During use, the solvent is altered due to hydrolysis and radiolysis, forming materials that influence product losses, product decontamination, and separation efficiencies. In most processes, the solvent is recycled after cleaning. Solvent cleaning generally involves scrubbing with a sodium carbonate solution. Studies at the Savannah River Laboratory have shown that carbonate washing, although removing residual solvent activity, does not remove more solvent-soluble binding ligands (formed by solvent degradation), which hold fission products in the solvent. Treatment of the solvent with a solid adsorbent after carbonate washing removes binding ligands and significantly improves recycled solvent performance. Laboratory work to establish the advantage of adsorbent cleaning and the development of a full-scale adsorption process is described. The application of this process for cleaning the first cycle solvent of a Savannah River Plant production process is discussed

Solvent substitutes

International Nuclear Information System (INIS)

Evanoff, S.P.

1995-01-01

The environmental and industrial hygiene regulations promulgated since 1980, most notably the Superfund Amendments and Reauthorization Act (SARA), the Hazardous and Solid Waste Amendments to the Resources Conservation and Recovery Act (RCRA), and the Clean Air Act Amendments of 1990, have brought about an increased emphasis on user exposure, hazardous waste generation, and air emissions. As a result, industry is performing a fundamental reassessment of cleaning solvents, processes, and procedures. The more progressive organizations have made their goal the elimination of solvents that may pose significant potential human health and environmental hazards. This chapter discusses solvent cleaning in metal-finishing, metal-manufacturing, and industrial maintenance applications; precision cleaning; and electronics manufacturing. Nonmetallic cleaning, adhesives, coatings, inks, and aerosols also will be addressed, but in a more cursory manner

Corrosion Study of Super Ferritic Stainless Steel UNS S44660 (26Cr-3Ni-3Mo) and Several Other Stainless Steel Grades (UNS S31603, S32101, and S32205) in Caustic Solution Containing Sodium Sulfide

Science.gov (United States)

Chasse, Kevin R.; Singh, Preet M.

2013-11-01

Electrochemical techniques, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were used in this study to show how the corrosion mechanism of several commercial grades of stainless steel in hot caustic solution is strongly influenced by the presence of sodium sulfide. Experimental results from super ferritic stainless steel UNS S44660 (26Cr-3Ni-3Mo) were compared to austenitic stainless steel UNS S31603, lean duplex stainless steel (DSS) UNS S32101, and standard DSS UNS S32205 in caustic solution, with and without sodium sulfide, at 443 K (170 °C). Weight loss measurements indicated that corrosion rates of UNS44660 were much lower than the other grades of stainless steel in the presence of the sodium sulfide. Potentiodynamic polarization and linear polarization resistance measurements showed that the electrochemical behavior was altered by the adhesion of sulfur species, which reduced the polarization resistances and increased the anodic current densities. SEM and XPS results imply that the surface films that formed in caustic solution containing sodium sulfide were defective due to the adsorption of sulfide, which destabilized the passive film and led to the formation of insoluble metal sulfide compounds.

Canyon solvent cleaning with solid adsorbents

International Nuclear Information System (INIS)

Reif, D.J.

1987-01-01

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

Purex process solvent: literature review

International Nuclear Information System (INIS)

Geier, R.G.

1979-10-01

This document summarizes the data on Purex process solvent presently published in a variety of sources. Extracts from these various sources are presented herein and contain the work done, the salient results obtained, and the original, unaltered conclusions of the author of each paper. Three major areas are addressed: solvent stability, solvent quality testing, and solvent treatment processes. 34 references, 44 tables

Purex process solvent: literature review

Energy Technology Data Exchange (ETDEWEB)

Geier, R.G.

1979-10-01

This document summarizes the data on Purex process solvent presently published in a variety of sources. Extracts from these various sources are presented herein and contain the work done, the salient results obtained, and the original, unaltered conclusions of the author of each paper. Three major areas are addressed: solvent stability, solvent quality testing, and solvent treatment processes. 34 references, 44 tables.

The Role of the Side Chain on the Performance of N-type Conjugated Polymers in Aqueous Electrolytes

KAUST Repository

Giovannitti, Alexander

2018-04-24

We report a design strategy that allows the preparation of solution processable n-type materials from low boiling point solvents for organic electrochemical transistors (OECTs). The polymer backbone is based on NDI-T2 copolymers where a branched alkyl side chain is gradually exchanged for a linear ethylene glycol-based side chain. A series of random copolymers was prepared with glycol side chain percentages of 0, 10, 25, 50, 75, 90, and 100 with respect to the alkyl side chains. These were characterized to study the influence of the polar side chains on interaction with aqueous electrolytes, their electrochemical redox reactions, and performance in OECTs when operated in aqueous electrolytes. We observed that glycol side chain percentages of >50% are required to achieve volumetric charging, while lower glycol chain percentages show a mixed operation with high required voltages to allow for bulk charging of the organic semiconductor. A strong dependence of the electron mobility on the fraction of glycol chains was found for copolymers based on NDI-T2, with a significant drop as alkyl side chains are replaced by glycol side chains.

The Role of the Side Chain on the Performance of N-type Conjugated Polymers in Aqueous Electrolytes

KAUST Repository

Giovannitti, Alexander; Maria, Iuliana P.; Hanifi, David; Donahue, Mary J.; Bryant, Daniel; Barth, Katrina J.; Makdah, Beatrice E.; Savva, Achilleas; Moia, Davide; Zetek, Matyá š; Barnes, Piers R.F.; Reid, Obadiah G.; Inal, Sahika; Rumbles, Garry; Malliaras, George G.; Nelson, Jenny; Rivnay, Jonathan; McCulloch, Iain

2018-01-01

We report a design strategy that allows the preparation of solution processable n-type materials from low boiling point solvents for organic electrochemical transistors (OECTs). The polymer backbone is based on NDI-T2 copolymers where a branched alkyl side chain is gradually exchanged for a linear ethylene glycol-based side chain. A series of random copolymers was prepared with glycol side chain percentages of 0, 10, 25, 50, 75, 90, and 100 with respect to the alkyl side chains. These were characterized to study the influence of the polar side chains on interaction with aqueous electrolytes, their electrochemical redox reactions, and performance in OECTs when operated in aqueous electrolytes. We observed that glycol side chain percentages of >50% are required to achieve volumetric charging, while lower glycol chain percentages show a mixed operation with high required voltages to allow for bulk charging of the organic semiconductor. A strong dependence of the electron mobility on the fraction of glycol chains was found for copolymers based on NDI-T2, with a significant drop as alkyl side chains are replaced by glycol side chains.

Tank 49H salt batch supernate qualification for ARP/MCU

Energy Technology Data Exchange (ETDEWEB)

Nash, C. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Peters, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Fink, S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Foster, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2008-08-25

This report covers the laboratory testing and analyses of Tank 49H Qualification Sample Sets A and C, performed in support of initial radioactive operations of Actinide Removal Process (ARP) and Modular Caustic-Side Solvent Extraction Unit (MCU). Major goals of this work include checking that Tank 49H was well mixed after the last receipt of Tank 23H, characterizing Tank 49H supernate after solids are settled so that its composition can be compared to waste acceptance and hazard criteria, verifying actinide and strontium adsorption with a small scale test using monosodium titanate (MST) and filtration, checking MCU solvent performance when applied to the liquid produced from MST contact, and verifying that in-tank settling after a minimum of 30 days was at least as good or better at reducing solids content after a Tank 49H to Tank 50H transfer occurred than what was observed in less time in the lab. The first four items were covered by Sample Set A. The fifth item was covered by Sample Set C, which had several analyses after compositing as required in the nuclear criticality safety evaluation (NCSE).

Solvent effect on the rate and equilibrium of reaction between 10-phenylphenoxarsine and methyl iodide. Vliyanie rastvoritelya na skorost' i ravnovesie reaktsii 10-fenilfenoksarsina s iodistym metilom

Energy Technology Data Exchange (ETDEWEB)

Gavrilov, V I; Gumerov, N S; Rakhmatullin, R R [Kazanskij Khimiko-Tekhnologicheskij Inst., Kazan (USSR)

1990-02-01

Effect of solvent nature on nucleophilic capacity of three-coordinated arsenic and the equilibrium state of 10-phenylphenoxarsine (PA) reaction with methyl iodide are studied. Kinetic investigations are carried out by the conductometry at 24,35,45 deg C. It is established that quaternization of PA with methyl iodide when substituting a solvent (ketone for alcohol) increases 3-14 times with simultaneous growth of the activation energy value. When transforming from aprotic solvents to protic ones PA interaction equilibrium with methyl iodide shifts to the side of arsonic salt formation.

Solvent/non-solvent sintering: a novel route to create porous microsphere scaffolds for tissue regeneration.

Science.gov (United States)

Brown, Justin L; Nair, Lakshmi S; Laurencin, Cato T

2008-08-01

Solvent/non-solvent sintering creates porous polymeric microsphere scaffolds suitable for tissue engineering purposes with control over the resulting porosity, average pore diameter, and mechanical properties. Five different biodegradable biocompatible polyphosphazenes exhibiting glass transition temperatures from -8 to 41 degrees C and poly (lactide-co-glycolide), (PLAGA) a degradable polymer used in a number of biomedical settings, were examined to study the versatility of the process and benchmark the process to heat sintering. Parameters such as: solvent/non-solvent sintering solution composition and submersion time effect the sintering process. PLAGA microsphere scaffolds fabricated with solvent/non-solvent sintering exhibited an interconnected porosity and pore size of 31.9% and 179.1 mum, respectively which was analogous to that of conventional heat sintered PLAGA microsphere scaffolds. Biodegradable polyphosphazene microsphere scaffolds exhibited a maximum interconnected porosity of 37.6% and a maximum compressive modulus of 94.3 MPa. Solvent/non-solvent sintering is an effective strategy for sintering polymeric microspheres, with a broad spectrum of glass transition temperatures, under ambient conditions making it an excellent fabrication route for developing tissue engineering scaffolds and drug delivery vehicles. (c) 2007 Wiley Periodicals, Inc.

Measurement and correlation of solubility of cefmenoxime hydrochloride in pure solvents and binary solvent mixtures

International Nuclear Information System (INIS)

Wang, Jinxiu; Xie, Chuang; Yin, Qiuxiang; Tao, Linggang; Lv, Jun; Wang, Yongli; He, Fang; Hao, Hongxun

2016-01-01

Highlights: • Solubility of cefmenoxime hydrochloride in pure and binary solvents was determined. • The experimental solubility data were correlated by thermodynamic models. • A model was employed to calculate the melting temperature of cefmenoxime hydrochloride. • Mixing thermodynamic properties of cefmenoxime hydrochloride were calculated. - Abstract: The solubility of cefmenoxime hydrochloride in pure solvents and binary solvent mixtures was measured at temperatures from (283.15 to 313.15) K by using the UV spectroscopic method. The results reveal that the solubility of cefmenoxime hydrochloride increases with increasing temperature in all solvent selected. The solubility of cefmenoxime hydrochloride reaches its maximum value when the mole fraction of isopropanol is 0.2 in the binary solvent mixtures of (isopropanol + water). The modified Apelblat equation and the NRTL model were successfully used to correlate the experimental solubility in pure solvents while the modified Apelblat equation, the CNIBS/R–K model and the Jouyban–Acree model were applied to correlate the solubility in binary solvent mixtures. In addition, the mixing thermodynamic properties of cefmenoxime hydrochloride in different solvents were also calculated based on the NRTL model and experimental solubility data.

Measurement and prediction of dabigatran etexilate mesylate Form II solubility in mono-solvents and mixed solvents

International Nuclear Information System (INIS)

Xiao, Yan; Wang, Jingkang; Wang, Ting; Ouyang, Jinbo; Huang, Xin; Hao, Hongxun; Bao, Ying; Fang, Wen; Yin, Qiuxiang

2016-01-01

Highlights: • Solubility of DEM Form II in mono-solvents and binary solvent mixtures was measured. • Regressed UNIFAC model was used to predict the solubility in solvent mixtures. • The experimental solubility data were correlated by different models. - Abstract: UV spectrometer method was used to measure the solubility data of dabigatran etexilate mesylate (DEM) Form II in five mono-solvents (methanol, ethanol, ethane-1,2-diol, DMF, DMAC) and binary solvent mixtures of methanol and ethanol in the temperature range from 287.37 K to 323.39 K. The experimental solubility data in mono-solvents were correlated with modified Apelblat equation, van’t Hoff equation and λh equation. GSM model and Modified Jouyban-Acree model were employed to correlate the solubility data in mixed solvent systems. And Regressed UNIFAC model was used to predict the solubility of DEM Form II in the binary solvent mixtures. Results showed that the predicted data were consistent with the experimental data.

Highly crystalline films of PCPDTBT with branched side chains by solvent vapor crystallization: influence on opto-electronic properties.

Science.gov (United States)

Fischer, Florian S U; Trefz, Daniel; Back, Justus; Kayunkid, Navaphun; Tornow, Benjamin; Albrecht, Steve; Yager, Kevin G; Singh, Gurpreet; Karim, Alamgir; Neher, Dieter; Brinkmann, Martin; Ludwigs, Sabine

2015-02-18

PCPDTBT, a marginally crystallizable polymer, is crystallized into a new crystal structure using solvent-vapor annealing. Highly ordered areas with three different polymer-chain orientations are identified using TEM/ED, GIWAXS, and polarized Raman spectroscopy. The optical and structural properties differ significantly from films prepared by standard device preparation protocols. Bilayer solar cells, however, show similar performance. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Caustics, counting maps and semi-classical asymptotics

Science.gov (United States)

Ercolani, N. M.

2011-02-01

This paper develops a deeper understanding of the structure and combinatorial significance of the partition function for Hermitian random matrices. The coefficients of the large N expansion of the logarithm of this partition function, also known as the genus expansion (and its derivatives), are generating functions for a variety of graphical enumeration problems. The main results are to prove that these generating functions are, in fact, specific rational functions of a distinguished irrational (algebraic) function, z0(t). This distinguished function is itself the generating function for the Catalan numbers (or generalized Catalan numbers, depending on the choice of weight of the parameter t). It is also a solution of the inviscid Burgers equation for certain initial data. The shock formation, or caustic, of the Burgers characteristic solution is directly related to the poles of the rational forms of the generating functions. As an intriguing application, one gains new insights into the relation between certain derivatives of the genus expansion, in a double-scaling limit, and the asymptotic expansion of the first Painlevé transcendent. This provides a precise expression of the Painlevé asymptotic coefficients directly in terms of the coefficients of the partial fractions expansion of the rational form of the generating functions established in this paper. Moreover, these insights point towards a more general program relating the first Painlevé hierarchy to the higher order structure of the double-scaling limit through the specific rational structure of generating functions in the genus expansion. The paper closes with a discussion of the relation of this work to recent developments in understanding the asymptotics of graphical enumeration. As a by-product, these results also yield new information about the asymptotics of recurrence coefficients for orthogonal polynomials with respect to exponential weights, the calculation of correlation functions for certain

Caustics, counting maps and semi-classical asymptotics

International Nuclear Information System (INIS)

Ercolani, N M

2011-01-01

This paper develops a deeper understanding of the structure and combinatorial significance of the partition function for Hermitian random matrices. The coefficients of the large N expansion of the logarithm of this partition function, also known as the genus expansion (and its derivatives), are generating functions for a variety of graphical enumeration problems. The main results are to prove that these generating functions are, in fact, specific rational functions of a distinguished irrational (algebraic) function, z 0 (t). This distinguished function is itself the generating function for the Catalan numbers (or generalized Catalan numbers, depending on the choice of weight of the parameter t). It is also a solution of the inviscid Burgers equation for certain initial data. The shock formation, or caustic, of the Burgers characteristic solution is directly related to the poles of the rational forms of the generating functions. As an intriguing application, one gains new insights into the relation between certain derivatives of the genus expansion, in a double-scaling limit, and the asymptotic expansion of the first Painlevé transcendent. This provides a precise expression of the Painlevé asymptotic coefficients directly in terms of the coefficients of the partial fractions expansion of the rational form of the generating functions established in this paper. Moreover, these insights point towards a more general program relating the first Painlevé hierarchy to the higher order structure of the double-scaling limit through the specific rational structure of generating functions in the genus expansion. The paper closes with a discussion of the relation of this work to recent developments in understanding the asymptotics of graphical enumeration. As a by-product, these results also yield new information about the asymptotics of recurrence coefficients for orthogonal polynomials with respect to exponential weights, the calculation of correlation functions for certain

PM and Their Staffs: Does Sustainable Manufacturing Mean ’Going Green’?

Science.gov (United States)

2011-11-01

the purpose of reducing the impacts of human  activity. The laws may be divided into two major areas:  1. pollution control and  remediation , 2...solvents, oil  residues from bilges Paint chips, spent  abrasives, surface  contaminants Metal Plating &  Surface Finishing Plating metals,  cyanide ...solvents,  acids and caustic  solutions Metal mist, fumes,  VOCs from solvents Metals,  cyanides ,  acids, alkalies,  organics and  solvents Sludge, spent

Sample Results from the Interim Salt Disposition Program Macrobatch 8 Tank 21H Qualification Samples

Energy Technology Data Exchange (ETDEWEB)

Peters, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Washington, A. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2015-01-01

Savannah River National Laboratory (SRNL) analyzed samples from Tank 21H in support of qualification of Macrobatch (Salt Batch) 8 for the Interim Salt Disposition Program (ISDP). An Actinide Removal Process (ARP) and several Extraction-Scrub- Strip (ESS) tests were also performed. This document reports characterization data on the samples of Tank 21H as well as simulated performance of ARP and the Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU). No issues with the projected Salt Batch 8 strategy are identified. A demonstration of the monosodium titanate (MST) (0.2 g/L) removal of strontium and actinides provided acceptable average decontamination factors for plutonium of 2.62 (4 hour) and 2.90 (8 hour); and average strontium decontamination factors of 21.7 (4 hour) and 21.3 (8 hour). These values are consistent with results from previous salt batch ARP tests. The two ESS tests also showed acceptable performance with extraction distribution ratios (D(Cs)) values of 52.5 and 50.4 for the Next Generation Solvent (NGS) blend (from MCU) and NGS (lab prepared), respectively. These values are consistent with results from previous salt batch ESS tests. Even though the performance is acceptable, SRNL recommends that a model for predicting extraction behavior for cesium removal for the blended solvent and NGS be developed in order to improve our predictive capabilities for the ESS tests.

Sample results from the Interim Salt Disposition Program Macrobatch 8 Tank 21H qualification samples

Energy Technology Data Exchange (ETDEWEB)

Peters, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Washington, II, A. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2015-01-13

Savannah River National Laboratory (SRNL) analyzed samples from Tank 21H in support of qualification of Macrobatch (Salt Batch) 8 for the Interim Salt Disposition Program (ISDP). An Actinide Removal Process (ARP) and several Extraction-Scrub-Strip (ESS) tests were also performed. This document reports characterization data on the samples of Tank 21H as well as simulated performance of ARP and the Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU). No issues with the projected Salt Batch 8 strategy are identified. A demonstration of the monosodium titanate (MST) (0.2 g/L) removal of strontium and actinides provided acceptable average decontamination factors for plutonium of 2.62 (4 hour) and 2.90 (8 hour); and average strontium decontamination factors of 21.7 (4 hour) and 21.3 (8 hour). These values are consistent with results from previous salt batch ARP tests. The two ESS tests also showed acceptable performance with extraction distribution ratios (D_(Cs)) values of 52.5 and 50.4 for the Next Generation Solvent (NGS) blend (from MCU) and NGS (lab prepared), respectively. These values are consistent with results from previous salt batch ESS tests. Even though the performance is acceptable, SRNL recommends that a model for predicting extraction behavior for cesium removal for the blended solvent and NGS be developed in order to improve our predictive capabilities for the ESS tests.

Iodine removing method in organic solvent

International Nuclear Information System (INIS)

Suzuki, Takeo; Sakurai, Manabu

1988-01-01

Purpose: To effectively remove iodine in an organic solvent to thereby remove iodine in the solvent that can be re-used or put to purning treatment. Method: Organic solvent formed from wastes of nuclear facilities is mixed with basic lead acetate, or silica gel or activated carbon incorporated with such a compound to adsorb iodine in the organic solvent to the basic lead acetate. Then, iodine in the organic solvent is removed by separating to eliminate the basic lead acetate adsorbing iodine from the organic solvent or by passing the organic solvent through a tower or column charged or pre-coated with silica gel or activated carbon incorporated with lead acetate. By using basic lead acetate as the adsorbents, iodine can effective by adsorbed and eliminated. Thus, the possibility of circumstantial release of iodine can be reduced upon reusing or burning treatment of the organic solvent. (Kamimura, M.)

Sensibilidade do carrapato Boophilus microplus a solventes Sensibility of Boophilus microplus tick to solvents

Directory of Open Access Journals (Sweden)

Ana Carolina de Souza Chagas

2003-02-01

Full Text Available Os experimentos envolvendo o uso de acaricidas sintéticos ou naturais, geralmente necessitam da utilização de um solvente. Com a finalidade de verificar a sensibilidade do carrapato bovino Boophilus microplus a diferentes solventes, larvas e fêmeas ingurgitadas deste ectoparasito foram expostas a sete solventes em cinco diferentes concentrações, na ausência e presença de azeite de oliva. Os resultados mostraram que a utilização do azeite de oliva não produz resultados diferentes estatisticamente em testes de larvas com papel impregnado, fato não verificado em testes de imersão de adultos com compostos hidrofílicos. A mortalidade média causada pelos solventes foi menor nos testes com papel impregnado, aumentando nos testes de imersão de larvas e de adultos. Solventes de baixo peso molecular e pouca viscosidade como o álcool metílico e o álcool etílico, não interferiram na mortalidade média em testes biológicos de B. microplus, principalmente em concentrações inferiores a 76%.Experiments carried out with synthetic or natural acaricides usually use a solvent. To investigate the sensitivity of Boophilus microplus cattle tick to different solvents, larvae and engorged female were subjected to seven solvents in five different concentrations. It was done in the presence and absence of olive oil. The results showed that the utilization of olive oil doesn't produce different statistical results in impregnated paper larvae test. It did not happen in adults immersion test with hydrophilic compounds. The mean mortality caused by solvents was small in impregnated paper larvae test, increasing in immersion tests of larvae and adults. Solvents with low molecular weight and viscosity like ethyl alcohol and methyl alcohol did not cause interference in the mortality of B. microplus in biological tests, mainly in concentrations below 76%.

Selection and design of solvents

DEFF Research Database (Denmark)

Gani, Rafiqul

and design of solvents will be presented together with application examples. The selection problem is defined as finding known chemicals that match the desired functions of a solvent for a specified set of applications. The design problem is defined as finding the molecular structure (or mixture of molecules....... With increasing interest on issues such as waste, sustainability, environmental impact and green chemistry, the selection and design of solvents have become important problems that need to be addressed during chemical product-process design and development. Systematic methods and tools suitable for selection......) that match the desired functions of a solvent for a specified set of applications. Use of organic chemicals and ionic liquids as solvents will be covered....

Hazardous solvent substitution

International Nuclear Information System (INIS)

Twitchell, K.E.

1995-01-01

This article is an overview of efforts at INEL to reduce the generation of hazardous wastes through the elimination of hazardous solvents. To aid in their efforts, a number of databases have been developed and will become a part of an Integrated Solvent Substitution Data System. This latter data system will be accessible through Internet

Organic Solvent Tropical Report

International Nuclear Information System (INIS)

COWLEY, W.L.

2000-01-01

This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an unmitigated organic solvent fire is within risk evaluation guidelines

Insecticide solvents: interference with insecticidal action.

Science.gov (United States)

Brattsten, L B; Wilkinson, C F

1977-06-10

Several commercial solvent mixtures commonly used as insecticide carriers in spray formulations increase by more than threefold the microsomal N-demethylation of p-chloro N-methylaniline in midgut preparations of southern army-worm (Spodoptera eridania) larvae exposed orally to the test solvents. Under laboratory conditions, the same solvent mixtures exhibit a protective action against the in vivo toxicity of the insecticide carbaryl to the larvae. The data are discussed with respect to possible solvent-insecticide interactions occurring under field conditions and, more broadly, to potential toxicological hazards of these solvents to humans.

Gaussian-Based Smooth Dielectric Function: A Surface-Free Approach for Modeling Macromolecular Binding in Solvents

Directory of Open Access Journals (Sweden)

Arghya Chakravorty

2018-03-01

Full Text Available Conventional modeling techniques to model macromolecular solvation and its effect on binding in the framework of Poisson-Boltzmann based implicit solvent models make use of a geometrically defined surface to depict the separation of macromolecular interior (low dielectric constant from the solvent phase (high dielectric constant. Though this simplification saves time and computational resources without significantly compromising the accuracy of free energy calculations, it bypasses some of the key physio-chemical properties of the solute-solvent interface, e.g., the altered flexibility of water molecules and that of side chains at the interface, which results in dielectric properties different from both bulk water and macromolecular interior, respectively. Here we present a Gaussian-based smooth dielectric model, an inhomogeneous dielectric distribution model that mimics the effect of macromolecular flexibility and captures the altered properties of surface bound water molecules. Thus, the model delivers a smooth transition of dielectric properties from the macromolecular interior to the solvent phase, eliminating any unphysical surface separating the two phases. Using various examples of macromolecular binding, we demonstrate its utility and illustrate the comparison with the conventional 2-dielectric model. We also showcase some additional abilities of this model, viz. to account for the effect of electrolytes in the solution and to render the distribution profile of water across a lipid membrane.

Computer Aided Solvent Selection and Design Framework

DEFF Research Database (Denmark)

Mitrofanov, Igor; Conte, Elisa; Abildskov, Jens

and computer-aided tools and methods for property prediction and computer-aided molecular design (CAMD) principles. This framework is applicable for solvent selection and design in product design as well as process design. The first module of the framework is dedicated to the solvent selection and design...... in terms of: physical and chemical properties (solvent-pure properties); Environment, Health and Safety (EHS) characteristic (solvent-EHS properties); operational properties (solvent–solute properties). 3. Performing the search. The search step consists of two stages. The first is a generation and property...... identification of solvent candidates using special software ProCAMD and ProPred, which are the implementations of computer-aided molecular techniques. The second consists of assigning the RS-indices following the reaction–solvent and then consulting the known solvent database and identifying the set of solvents...

Improvements in solvent extraction columns

International Nuclear Information System (INIS)

Aughwane, K.R.

1987-01-01

Solvent extraction columns are used in the reprocessing of irradiated nuclear fuel. For an effective reprocessing operation a solvent extraction column is required which is capable of distributing the feed over most of the column. The patent describes improvements in solvent extractions columns which allows the feed to be distributed over an increased length of column than was previously possible. (U.K.)

Gas separation by composite solvent-swollen membranes

Science.gov (United States)

Matson, Stephen L.; Lee, Eric K. L.; Friesen, Dwayne T.; Kelly, Donald J.

1989-01-01

There is disclosed a composite immobulized liquid membrane of a solvent-swollen polymer and a microporous organic or inorganic support, the solvent being at least one highly polar solvent containing at least one nitrogen, oxygen, phosphorous or sulfur atom, and having a boiling point of at least 100.degree. C. and a specified solubility parameter. The solvent or solvent mixture is homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. The membrane is suitable for acid gas scrubbing and oxygen/nitrogen separation.

Gas separation by composite solvent-swollen membranes

Science.gov (United States)

Matson, S.L.; Lee, E.K.L.; Friesen, D.T.; Kelly, D.J.

1989-04-25

There is disclosed a composite immobilized liquid membrane of a solvent-swollen polymer and a microporous organic or inorganic support, the solvent being at least one highly polar solvent containing at least one nitrogen, oxygen, phosphorus or sulfur atom, and having a boiling point of at least 100 C and a specified solubility parameter. The solvent or solvent mixture is homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. The membrane is suitable for acid gas scrubbing and oxygen/nitrogen separation. 3 figs.

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

International Nuclear Information System (INIS)

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

1979-01-01

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

Processing of polymers using reactive solvents

NARCIS (Netherlands)

Lemstra, P.J.; Kurja, J.; Meijer, H.E.H.; Meijer, H.E.H.

1997-01-01

A review with many refs. on processing of polymers using reactive solvents including classification of synthetic polymers, guidelines for the selection of reactive solvents, basic aspects of processing, examples of intractable and tractable polymer/reactive solvent system

40 CFR Table 4 to Subpart Oooo of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... 63—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction... formulation data. Solvent/solvent blend CAS. No. Averageorganic HAP mass fraction Typical organic HAP, percent...

Effects of solvent and structure on the reactivity of 6-substituted nicotinic acids with diazodiphenylmethane in aprotic solvents

Directory of Open Access Journals (Sweden)

BRATISLAV Ž. JOVANOVIĆ

2009-12-01

Full Text Available The rate constants for the reactions of diazodiphenylmethane (DDM with 6-substituted nicotinic acids in aprotic solvents at 30 °C were determined. The obtained second order rate constants in aprotic solvents, together with literature data for benzoic and nicotinic acids in protic solvents, were used for the calculation of solvent effects, employing the Kamlet-Taft solvatochromic equation (linear solvation energy relationship – LSER in the form: log k = log k0 + s* + a + b. The correlations of the kinetic data were performed by means of multiple linear regression analysis taking appropriate solvent parameters. The sign of the equation coefficients (s, a and b were in agreement with the postulated reaction mechanism, and the mode of the solvent influences on the reaction rate is discussed based on the correlation results. A similar contribution of the non-specific solvent effect and electrophilic solvation was observed for all acids, while the highest contribution of nucleophilic solvation was influenced by their high acidity. Correlation analysis of the rate data with substituent p parameters in an appropriate solvent using the Hammett equation was also performed. The substituent effect on the acid reactivity was higher in aprotic solvents of higher dipolarity/polarizability. The mode of the transmission of the substituent effect is discussed in light of the contribution of solute–solvent interaction on the acid reactivity.

40 CFR Table 3 to Subpart IIIi of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the... Solvent/solvent blend CAS. No. Averageorganic HAP mass fraction Typical organic HAP, percent by mass 1...

40 CFR Table 5 to Subpart Qqqq of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the.... Solvent/solvent blend CAS. No. Average organic HAP mass fraction Typical organic HAP, percent by mass 1...

O esôfago de Barrett associado à estenose cáustica do esôfago Barrett's esophagus associated to caustic stenosis of the esophagus

Directory of Open Access Journals (Sweden)

Nelson Adami Andreollo

2003-09-01

Full Text Available RACIONAL: A estenose esofágica secundária à ingestão de produtos cáusticos é freqüente no Brasil, principalmente como tentativa de suicídio. O esôfago de Barrett surge como conseqüência do refluxo gastroesofágico crônico. A literatura pesquisada mostrou que esta associação é muito rara. CASUÍSTICA E MÉTODOS: De 1981 a 2000 foram admitidos e tratados no Gastrocentro-UNICAMP (Universidade Estadual de Campinas, SP. 120 doentes com estenose cáustica do esôfago e durante o seguimento destes, foram encontrados 9 casos associados com o esôfago de Barrett (7,5%. O tempo de ingestão do cáustico variou de 4 a 54 anos (média de 29 anos e eram quatro homens e cinco mulheres, oito brancos e um negro, com idade média de 57,7 anos (43 a 72 anos. RESULTADOS: Todos os casos apresentavam disfagia e a endoscopia digestiva alta flexível mostrou áreas de estenose e seqüelas de esofagite cáustica. Três pacientes referiram sintomas de refluxo gastroesofágico, mas hérnia de hiato foi encontrada em apenas um caso. O esôfago de Barrett foi encontrado no terço médio do esôfago em três casos, acima das áreas de estenose, e nos demais, no terço distal. A disfagia foi tratada com dilatações esofágicas periódicas. Dois pacientes apresentando sintomas de refluxo grave foram submetidos a fundoplicatura à Nissen modificado através de videolaparoscopia, com bons resultados. CONCLUSÕES: O esôfago de Barrett nesses doentes poderia estar associado com a ingestão de cáustico, porque nem sempre esteve associado à esofagite por refluxo. É muito importante o seguimento desses doentes e realização periódica de endoscopias digestivas com biopsias do esôfago de Barrett, devido à possibilidade de malignização.BACKGROUND: The esophageal stenosis secondary to the ingestion of caustic products is frequent in Brazil, mainly due to an attempt suicide. The Barrett's esophagus is consequence of the chronic gastroesophageal reflux. The

Solubility of daidzin in different organic solvents and (ethyl alcohol + water) mixed solvents

International Nuclear Information System (INIS)

Fan, Jie-Ping; Yang, Dan; Xu, Xiao-Kang; Guo, Xiao-Jie; Zhang, Xue-Hong

2015-01-01

Highlights: • The solubilities of daidzin were measured in various solvents. • The solubility data were correlated by three models. • The thermodynamic properties of the dissolution process were also determined. - Abstract: The solubility of daidzin in different organic solvents and (ethyl alcohol + water) mixed solvents was measured by high performance liquid chromatography (HPLC) analysis method from T = (283.2 to 323.2) K at atmosphere pressure. The results show that at higher temperature more daidzin dissolves, and moreover, the solubility increases with the ethyl alcohol mole fraction increase in the (ethyl alcohol + water) mixed solvents. The experimental solubility values were correlated by a simplified thermodynamic equation, λh equation and modified Apelblat equation. Based on the solubility of daidzin, the enthalpy and entropy of solution were also evaluated by van’t Hoff equation. The results illustrated that the dissolution process of daidzin is endothermic and entropy driven

Effects of solvent concentration and composition on protein dynamics: 13C MAS NMR studies of elastin in glycerol-water mixtures.

Science.gov (United States)

Demuth, Dominik; Haase, Nils; Malzacher, Daniel; Vogel, Michael

2015-08-01

We use (13)C CP MAS NMR to investigate the dependence of elastin dynamics on the concentration and composition of the solvent at various temperatures. For elastin in pure glycerol, line-shape analysis shows that larger-scale fluctuations of the protein backbone require a minimum glycerol concentration of ~0.6 g/g at ambient temperature, while smaller-scale fluctuations are activated at lower solvation levels of ~0.2 g/g. Immersing elastin in various glycerol-water mixtures, we observe at room temperature that the protein mobility is higher for lower glycerol fractions in the solvent and, thus, lower solvent viscosity. When decreasing the temperature, the elastin spectra approach the line shape for the rigid protein at 245 K for all studied samples, indicating that the protein ceases to be mobile on the experimental time scale of ~10(-5) s. Our findings yield evidence for a strong coupling between elastin fluctuations and solvent dynamics and, hence, such interaction is not restricted to the case of protein-water mixtures. Spectral resolution of different carbon species reveals that the protein-solvent couplings can, however, be different for side chain and backbone units. We discuss these results against the background of the slaving model for protein dynamics. Copyright © 2015 Elsevier B.V. All rights reserved.

Adaptive Resolution Simulation of MARTINI Solvents

NARCIS (Netherlands)

Zavadlav, Julija; Melo, Manuel N.; Cunha, Ana V.; de Vries, Alex H.; Marrink, Siewert J.; Praprotnik, Matej

We present adaptive resolution dynamics simulations of aqueous and apolar solvents coarse-grained molecular models that are compatible with the MARTINI force field. As representatives of both classes solvents we have chosen liquid water and butane, respectively, at ambient temperature. The solvent

Green and Bio-Based Solvents.

Science.gov (United States)

Calvo-Flores, Francisco G; Monteagudo-Arrebola, María José; Dobado, José A; Isac-García, Joaquín

2018-04-24

Chemical reactions and many of the procedures of separation and purification employed in industry, research or chemistry teaching utilize solvents massively. In the last decades, with the birth of Green Chemistry, concerns about the employment of solvents and the effects on human health, as well as its environmental impacts and its dependence on non-renewable raw materials for manufacturing most of them, has drawn the attention of the scientific community. In this work, we review the concept of green solvent and the properties and characteristics to be considered green. Additionally, we discuss the different possible routes to prepare many solvents from biomass, as an alternative way to those methods currently applied in the petrochemical industry.

Solvent Extraction of Furfural From Biomass

Science.gov (United States)

Humphrey, M. F.

1984-01-01

Solvent-extraction method reduces energy required to remove furfural produced during acid hydrolysis of biomass. Acid hydrolysis performed in vessel containing both solvents and reacting ingredients. With intimate contact between solvents and aqueous hydrolyis liqour, furfural removed form liquor almost as fast as it forms.

Organic Solvent Tolerant Lipases and Applications

Directory of Open Access Journals (Sweden)

Shivika Sharma

2014-01-01

Full Text Available Lipases are a group of enzymes naturally endowed with the property of performing reactions in aqueous as well as organic solvents. The esterification reactions using lipase(s could be performed in water-restricted organic media as organic solvent(s not only improve(s the solubility of substrate and reactant in reaction mixture but also permit(s the reaction in the reverse direction, and often it is easy to recover the product in organic phase in two-phase equilibrium systems. The use of organic solvent tolerant lipase in organic media has exhibited many advantages: increased activity and stability, regiospecificity and stereoselectivity, higher solubility of substrate, ease of products recovery, and ability to shift the reaction equilibrium toward synthetic direction. Therefore the search for organic solvent tolerant enzymes has been an extensive area of research. A variety of fatty acid esters are now being produced commercially using immobilized lipase in nonaqueous solvents. This review describes the organic tolerance and industrial application of lipases. The main emphasis is to study the nature of organic solvent tolerant lipases. Also, the potential industrial applications that make lipases the biocatalysts of choice for the present and future have been presented.

Acetone-based cellulose solvent.

Science.gov (United States)

Kostag, Marc; Liebert, Tim; Heinze, Thomas

2014-08-01

Acetone containing tetraalkylammonium chloride is found to be an efficient solvent for cellulose. The addition of an amount of 10 mol% (based on acetone) of well-soluble salt triethyloctylammonium chloride (Et3 OctN Cl) adjusts the solvent's properties (increases the polarity) to promote cellulose dissolution. Cellulose solutions in acetone/Et3 OctN Cl have the lowest viscosity reported for comparable aprotic solutions making it a promising system for shaping processes and homogeneous chemical modification of the biopolymer. Recovery of the polymer and recycling of the solvent components can be easily achieved. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Computer-aided tool for solvent selection in pharmaceutical processes: Solvent swap

DEFF Research Database (Denmark)

Papadakis, Emmanouil; K. Tula, Anjan; Gernaey, Krist V.

-liquid equilibria). The application of the developed model-based framework is highlighted through several cases studies published in the literature. In the current state, the framework is suitable for problems where the original solvent is exchanged by distillation. A solvent selection guide for fast of suitable......-aided framework with the objective to assist the pharmaceutical industry in gaining better process understanding. A software interface to improve the usability of the tool has been created also....

Effects of solvent evaporation conditions on solvent vapor annealed cylinder-forming block polymer thin films

Science.gov (United States)

Grant, Meagan; Jakubowski, William; Nelson, Gunnar; Drapes, Chloe; Baruth, A.

Solvent vapor annealing is a less time and energy intensive method compared to thermal annealing, to direct the self-assembly of block polymer thin films. Periodic nanostructures have applications in ultrafiltration, magnetic arrays, or other structures with nanometer dimensions, driving its continued interest. Our goal is to create thin films with hexagonally packed, perpendicular aligned cylinders of poly(lactide) in a poly(styrene) matrix that span the thickness of the film with low anneal times and low defect densities, all with high reproducibility, where the latter is paramount. Through the use of our computer-controlled, pneumatically-actuated, purpose-built solvent vapor annealing chamber, we have the ability to monitor and control vapor pressure, solvent concentration within the film, and solvent evaporation rate with unprecedented precision and reliability. Focusing on evaporation, we report on two previously unexplored areas, chamber pressure during solvent evaporation and the flow rate of purging gas aiding the evaporation. We will report our exhaustive results following atomic force microscopy analysis of films exposed to a wide range of pressures and flow rates. Reliably achieving well-ordered films, while occurring within a large section of this parameter space, was correlated with high-flow evaporation rates and low chamber pressures. These results have significant implications on other methods of solvent annealing, including ``jar'' techniques.

On linear correlation between interfacial tension of water-solvent interface solubility of water in organic solvents and parameters of diluent effect scale

International Nuclear Information System (INIS)

Mezhov, Eh.A.; Khananashvili, N.L.; Shmidt, V.S.

1988-01-01

Presence of linear correlation between water solubility in nonmiscible with it organic solvents, interfacial tension of water-solvent interface, on the one hand, and solvent effect scale parameters and these solvents π* - on the other hand, is established. It allows, using certain tabular parameters of solvent effect or each solvent π*, to predict values of interfacial tension and water solubility for corresponding systems. It is shown, that solvent effect scale allows to predict values more accurately, than other known solvent scales, as it in contrast to other scales characterizes solvents, which are in equilibrium with water

Photophysics of Curcumin excited state in toluene-polar solvent mixtures: Role of H-bonding properties of the polar solvent

Energy Technology Data Exchange (ETDEWEB)

Saini, R.K.; Das, K., E-mail: kaustuv@rrcat.gov.in

2014-01-15

Excited state dynamics of Curcumin in binary solvent mixtures of toluene and polar H-bonding solvents were compared by using an instrument endowed with 40 ps time resolution. The solvation time constant of Curcumin increases significantly (and can therefore be measured) in polar solvents which have, either, both H-bond donating and accepting ability, or, only H-bond donating ability. These results suggest that the rate limiting step in the excited state dynamics of the pigment might be the formation and reorganization of the intermolecular H-bonding between the keto group of the pigment and the H-bond donating moieties of the polar solvent. -- Highlights: • Excited state dynamics of Curcumin in a binary solvent mixture of toluene and three polar H-bonding solvents were compared. • The solvation time constant increases significantly with polar solvents having, H-bond donating and accepting, or, H-bond donating ability. • Observed results suggest that H-bonding property of polar solvent plays an important role in the excited state dynamics. • Intermolecular H-bonding between the keto group of the pigment and polar solvent may be the rate limiting step.

Photophysics of Curcumin excited state in toluene-polar solvent mixtures: Role of H-bonding properties of the polar solvent

International Nuclear Information System (INIS)

Saini, R.K.; Das, K.

2014-01-01

Excited state dynamics of Curcumin in binary solvent mixtures of toluene and polar H-bonding solvents were compared by using an instrument endowed with 40 ps time resolution. The solvation time constant of Curcumin increases significantly (and can therefore be measured) in polar solvents which have, either, both H-bond donating and accepting ability, or, only H-bond donating ability. These results suggest that the rate limiting step in the excited state dynamics of the pigment might be the formation and reorganization of the intermolecular H-bonding between the keto group of the pigment and the H-bond donating moieties of the polar solvent. -- Highlights: • Excited state dynamics of Curcumin in a binary solvent mixture of toluene and three polar H-bonding solvents were compared. • The solvation time constant increases significantly with polar solvents having, H-bond donating and accepting, or, H-bond donating ability. • Observed results suggest that H-bonding property of polar solvent plays an important role in the excited state dynamics. • Intermolecular H-bonding between the keto group of the pigment and polar solvent may be the rate limiting step

Laboratory-scale integrated ARP filter test

Energy Technology Data Exchange (ETDEWEB)

Poirier, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Burket, P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2016-03-01

The Savannah River Site (SRS) is currently treating radioactive liquid waste with the Actinide Removal Process (ARP) and the Modular Caustic Side Solvent Extraction Unit (MCU). Recently, the low filter flux through the ARP of approximately 5 gallons per minute has limited the rate at which radioactive liquid waste can be treated. Salt Batch 6 had a lower processing rate and required frequent filter cleaning. There is a desire to understand the causes of the low filter flux and to increase ARP/MCU throughput. This task attempted to simulate the entire ARP process, including multiple batches (5), washing, chemical cleaning, and blending the feed with heels and recycle streams. The objective of the tests was to determine whether one of these processes is causing excessive fouling of the crossflow or secondary filter. The authors conducted the tests with feed solutions containing 6.6 M sodium Salt Batch 6 simulant supernate with no MST.

Linear correlation of interfacial tension at water-solvent interface, solubility of water in organic solvents, and SE* scale parameters

International Nuclear Information System (INIS)

Mezhov, E.A.; Khananashvili, N.L.; Shmidt, V.S.

1988-01-01

A linear correlation has been established between the solubility of water in water-immiscible organic solvents and the interfacial tension at the water-solvent interface on the one hand and the parameters of the SE* and π* scales for these solvents on the other hand. This allows us, using the known tabulated SE* or π* parameters for each solvent, to predict the values of the interfacial tension and the solubility of water for the corresponding systems. We have shown that the SE* scale allows us to predict these values more accurately than other known solvent scales, since in contrast to other scales it characterizes solvents found in equilibrium with water

29 CFR 1915.32 - Toxic cleaning solvents.

Science.gov (United States)

2010-07-01

... 29 Labor 7 2010-07-01 2010-07-01 false Toxic cleaning solvents. 1915.32 Section 1915.32 Labor... Preservation § 1915.32 Toxic cleaning solvents. (a) When toxic solvents are used, the employer shall employ one or more of the following measures to safeguard the health of employees exposed to these solvents. (1...

Analysis of recovered solvents from coal liquefaction in a flowing-solvent reactor by SEC and UV-fluorescence

Energy Technology Data Exchange (ETDEWEB)

Li, W.Y.; Feng, J.; Xie, K.C.; Kandiyoti, R. [Taiyuan University of Technology, Taiyuan (China)

2005-08-01

Point of Ayr coal has been extracted using three solvents: tetralin, quinoline and 1-methyl-2-pyrrolidinone (NMP); at two temperatures: 350 {sup o}C and 450{sup o}C, corresponding approximately to before and after the onset of massive covalent bond scission by pyrolysis. These solvents differ in solvent power and the ability to donate hydrogen atoms to stabilize free radicals produced by pyrolysis of the coal. Analysis of the fresh solvents and recovered solvents from coal liquefaction was achieved by size exclusion chromatography and UV-fluorescence spectroscopy. In the blank run, it was testified that the filling material sand and the steel powder did not react with solvent with increasing reaction temperature. The role of hydrogen donation in the tetralin extracts was to increase the proportion of large molecules with increasing extraction temperature. Quinoline and NMP both have the powerful extracting capability to get more materials out of coal with increasing extraction temperature.

Analysis of recovered solvents from coal liquefaction in a flowing-solvent reactor by SEC and UV-fluorescence

Energy Technology Data Exchange (ETDEWEB)

Wen-Ying Li; Jie Feng; Ke-Chang Xie; R. Kandiyoti [Taiyuan University of Technology, Taiyuan (China). Key Laboratory of Coal Science and Technology for Ministry of Education and Shanxi Province

2005-08-01

Point of Ayr coal has been extracted using three solvents: tetralin, quinoline and 1-methyl-2-pyrrolidinone (NMP); at two temperatures: 350{sup o}C and 450{sup o}C, corresponding approximately to before and after the onset of massive covalent bond scission by pyrolysis. These solvents differ in solvent power and the ability to donate hydrogen atoms to stabilize free radicals produced by pyrolysis of the coal. Analysis of the fresh solvents and recovered solvents from coal liquefaction was achieved by size exclusion chromatography and UV-fluorescence spectroscopy. In the blank run, it was testified that the filling material sand and the steel powder did not react with solvent with increasing reaction temperature. The role of hydrogen donation in the tetralin extracts was to increase the proportion of large molecules with increasing extraction temperature. Quinoline and NMP both have the powerful extracting capability to get more materials out of coal with increasing extraction temperature.

Organic solvent topical report

International Nuclear Information System (INIS)

COWLEY, W.L.

1999-01-01

This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an organic solvent fire is within risk evaluation guidelines. This report updates information contained in Analysis of Consequences of Postulated Solvent Fires in Hanford Site Waste Tanks. WHC-SD-WM-CN-032. Rev. 0A (Cowley et al. 1996). However, this document will not replace Cowley et al (1996) as the primary reference for the Basis for Interim Operation (BIO) until the recently submitted BIO amendment (Hanson 1999) is approved by the US Department of Energy. This conclusion depends on the use of controls for preventing vehicle fuel fires and for limiting the use of flame cutting in areas where hot metal can fall on the waste surface.The required controls are given in the Tank Waste Remediation System Technical Safety Requirements (Noorani 1997b). This is a significant change from the conclusions presented in Revision 0 of this report. Revision 0 of this calcnote concluded that some organic solvent fire scenarios exceeded risk evaluation guidelines, even with controls imposed

Organic solvent topical report

Energy Technology Data Exchange (ETDEWEB)

COWLEY, W.L.

1999-05-13

This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an organic solvent fire is within risk evaluation guidelines. This report updates information contained in Analysis of Consequences of Postulated Solvent Fires in Hanford Site Waste Tanks. WHC-SD-WM-CN-032. Rev. 0A (Cowley et al. 1996). However, this document will not replace Cowley et al (1996) as the primary reference for the Basis for Interim Operation (BIO) until the recently submitted BIO amendment (Hanson 1999) is approved by the US Department of Energy. This conclusion depends on the use of controls for preventing vehicle fuel fires and for limiting the use of flame cutting in areas where hot metal can fall on the waste surface.The required controls are given in the Tank Waste Remediation System Technical Safety Requirements (Noorani 1997b). This is a significant change from the conclusions presented in Revision 0 of this report. Revision 0 of this calcnote concluded that some organic solvent fire scenarios exceeded risk evaluation guidelines, even with controls imposed.

Conformational analysis of glutamic acid: a density functional approach using implicit continuum solvent model.

Science.gov (United States)

Turan, Başak; Selçuki, Cenk

2014-09-01

Amino acids are constituents of proteins and enzymes which take part almost in all metabolic reactions. Glutamic acid, with an ability to form a negatively charged side chain, plays a major role in intra and intermolecular interactions of proteins, peptides, and enzymes. An exhaustive conformational analysis has been performed for all eight possible forms at B3LYP/cc-pVTZ level. All possible neutral, zwitterionic, protonated, and deprotonated forms of glutamic acid structures have been investigated in solution by using polarizable continuum model mimicking water as the solvent. Nine families based on the dihedral angles have been classified for eight glutamic acid forms. The electrostatic effects included in the solvent model usually stabilize the charged forms more. However, the stability of the zwitterionic form has been underestimated due to the lack of hydrogen bonding between the solute and solvent; therefore, it is observed that compact neutral glutamic acid structures are more stable in solution than they are in vacuum. Our calculations have shown that among all eight possible forms, some are not stable in solution and are immediately converted to other more stable forms. Comparison of isoelectronic glutamic acid forms indicated that one of the structures among possible zwitterionic and anionic forms may dominate over the other possible forms. Additional investigations using explicit solvent models are necessary to determine the stability of charged forms of glutamic acid in solution as our results clearly indicate that hydrogen bonding and its type have a major role in the structure and energy of conformers.

Structural effects of a light emitting copolymer having perylene moieties in the side chain on the electroluminescent characteristics

International Nuclear Information System (INIS)

Lee, Chang Ho; Ryu, Seung Hoon; Jang, Hee Dong; Oh, Se Young

2004-01-01

We have synthesized a novel side chain light emitting copolymer. The side chain light emitting copolymer has a perylene moiety as an emitting unit and methylmethacrylate (MMA) as a spacer to decrease the concentration quenching of light emitting site in the polymer intrachain. These polymers are very soluble in most organic solvents such as monochlorobenzene, tetrahydrofuran, chloroform and benzene. The single-layered electroluminescent (EL) device consisting of ITO/carrier transporting copolymer and light emitting copolymer/Al was manufactured. The carrier transporting copolymer has triphenylamine moiety as a hole transporting unit and triazine moiety as an electron transporting unit in the polymer side chain. This device exhibits maximum external quantum efficiency when the MMA contents of light emitting copolymer is 30 wt.%. In particular, the device emits more blue light as MMA contents increase

Implicit solvent simulations of DNA and DNA-protein complexes: Agreement with explicit solvent vs experiment

Czech Academy of Sciences Publication Activity Database

Chocholoušová, Jana; Feig, M.

2006-01-01

Roč. 110, č. 34 (2006), s. 17240-17251 ISSN 1520-6106 Keywords : implicit solvent * explicit solvent * protein DNA complex Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.115, year: 2006

Biomolecular-solvent stereodynamic coupling probed by deuteration

International Nuclear Information System (INIS)

Fornili, S.L.; Leone, M.; Madonia, F.; Migliore, M.; Palma-Vittorelli, M.B.; Palma, M.U.; San Biagio, P.L.

1983-01-01

Thermodynamic interpretation of experiments with isotopically perturbed solvent supports the view that solvent stereodynamics is directly relevant to thermodynamic stability of biomolecules. According with the current understanding of the structure of the aqueous solvent, in any stereodynamic configuration of the latter, connectivity pathways are identifiable for their topologic and order properties. Perturbing the solvent by isotopic substitution or, e.g., by addition of co-solvents, can therefore be viewed as reinforcing or otherwise perturbing these topologic structures. This microscopic model readily visualizes thermodynamic interpretation. In conclusion, the topologic stereodynamic structures of connectivity pathways in the solvent, as modified by interaction with solutes, acquire a specific thermodynamic and biological significance, and the problem of thermodynamic and functional stability of biomolecules is seen in its full pertinent phase space

Problems on gravitational collapse of interstellar gas clouds. II. Caustic and critical times for a one-dimensional hydrodynamic model

Energy Technology Data Exchange (ETDEWEB)

Ferraioli, F; Virgopia, N [Rome Univ. (Italy). Ist. di Matematica; Ruggeri, T [Bologna Univ. (Italy)

1978-07-01

The gravitational collapse of a spherically symmetric interstellar gas cloud has been investigated following the non-linear discontinuity waves propagation theory. It has been pointed out that macroscopic phenomena, such as the process of fragmentation, can arise (shock wave formation) - even in the case of spherical symmetry - at times smaller than the free-fall time tsub(ff), provided the initial data of the Cauchy problem be discontinuous within a sphere of radius R(mean) < Rsub(cloud) (caustic cases). It has also been proved that strong discontinuities outside the mentioned sphere may generate critical times tsub(cr) < tsub(ff) (depending on the typical non-linear structure of the differential system). The cooling-heating function plays an important role in contrasting the formation of shock waves.

Structural transition of a homopolymer in solvents mixture

International Nuclear Information System (INIS)

Guettari, Moez; Aschi, Adel; Gomati, Riadh; Gharbi, Abdelhafidh

2008-01-01

The present work is aimed at studying the thermodynamic behaviour of a polymer in solvents mixture. Dynamic light scattering is used to measure the hydrodynamic radius of polyvinylpyrrolidone (M w = 360,000 g/mol), in water/methanol solvents mixture, versus the mixed solvents composition at 25 deg. C. Then, we show that the polymer conformation adopts the Coil-Globule-Coil structure when the methanol molar fraction X A is varied. This transition is attributed to solvent quality change which result from water and methanol complex formation. The polymer contraction rate calculated for each composition takes its maximum value at X A = 0.17. Hildebrand theory assuming the solvents mixture as an equivalent solvent was used to analyze the change in mixed solvents quality. These changes can be attributed to dispersive forces in solvents mixture

Effect of solvent polarity and temperature on the spectral and thermodynamic properties of exciplexes of 1-cyanonaphthalene with hexamethylbenzene in organic solvents

International Nuclear Information System (INIS)

Asim, Sadia; Mansha, Asim; Grampp, Günter; Landgraf, Stephan; Zahid, Muhammad; Bhatti, Ijaz Ahmad

2014-01-01

Study of the effect of solvent polarity and temperature is done on the exciplex emission spectra of 1-cyanonaphthalene with hexamethylbenzene. Exciplex system is studied in the range of partially polar solvents and in solvent mixture of propyl acetate and butyronitrile. The unique feature of this solvent mixture is that only the solvent polarity changes (6.0≤ε s ≤24.7) with the change in the mole fraction of solvents whereas the solvent viscosity and refractive index remains unaffected. Thermodynamic properties are calculated according to the models developed by Weller and Kuzmin. Fluorescence lifetimes for both the fluorophore as well as the exciplex are evaluated in all used solvents. Exciplex energetics as a function of solvent polarity and temperature are also discussed. Kuzmin model of self-consistent polarization is used for the explanation of the exciplex emission spectra. The effects of solvent polarity and temperature on energy of zero–zero transitions (hv 0 / ), Huang–Rhys factor (S), Gauss broadening of vibronic level (σ) and the dominant high-frequency vibration (hν ν ) are investigated. The strong dependence of exciplex stability and energetics upon the solvent polarity and temperature are observed. Full charge transfer exciplexes were observed in solvents of all polarities and stronger exciplex with large emission intensities were found in solvents of low polarities but with the increase in solvent polarity the exciplex becomes weak and they dissociate fastly into radical ion pairs. The kinetic model of Kuzmin was observed to reduce into the Weller kinetic model for this exciplex system with ∆G ET = −0.22 eV and the spectral shift, h∆ν>0.2 eV. - Highlights: • Exciplex formed as a result of mixing of charge transfer and locally excited states. • Effect of solvents polarity and temperature on the exciplex stability and thermodynamics. • Solvent polarity will decide the formation of contact radical ion pair or solvent separated

Aminosilicone solvent recovery methods and systems

Science.gov (United States)

Spiry, Irina Pavlovna; Perry, Robert James; Wood, Benjamin Rue; Singh, Surinder Prabhjot; Farnum, Rachel Lizabeth; Genovese, Sarah Elizabeth

2018-02-13

The present invention is directed to aminosilicone solvent recovery methods and systems. The methods and systems disclosed herein may be used to recover aminosilicone solvent from a carbon dioxide containing vapor stream, for example, a vapor stream that leaves an aminosilicone solvent desorber apparatus. The methods and systems of the invention utilize a first condensation process at a temperature from about 80.degree. C. to about 150.degree. C. and a second condensation process at a temperature from about 5.degree. C. to about 75.degree. C. The first condensation process yields recovered aminosilicone solvent. The second condensation process yields water.

Work ability score of solvent-exposed workers.

Science.gov (United States)

Furu, Heidi; Sainio, Markku; Hyvärinen, Hanna-Kaisa; Kaukiainen, Ari

2018-03-28

Occupational chronic solvent encephalopathy (CSE), characterized by neurocognitive dysfunction, often leads to early retirement. However, only the more severe cases are diagnosed with CSE, and little is known about the work ability of solvent-exposed workers in general. The aim was to study memory and concentration symptoms, work ability and the effect of both solvent-related and non-occupational factors on work ability, in an actively working solvent-exposed population. A questionnaire on exposure and health was sent to 3640 workers in four solvent-exposed fields, i.e. painters and floor-layers, boat builders, printers, and metal workers. The total number of responses was 1730. We determined the work ability score (WAS), a single question item of the Work Ability Index, and studied solvent exposure, demographic factors, Euroquest memory and concentration symptoms, chronic diseases, and employment status using univariate and multivariate analyses. The findings were compared to those of a corresponding national blue-collar reference population (n = 221), and a small cohort of workers with CSE (n = 18). The proportion of workers with memory and concentration symptoms was significantly associated with solvent exposure. The WAS of solvent-exposed workers was lower than that of the national blue-collar reference group, and the difference was significant in the oldest age group (those aged over 60). Solvent-exposed worker's WAS were higher than those of workers diagnosed with CSE. The WAS were lowest among painters and floor-layers, followed by metal workers and printers, and highest among boat builders. The strongest explanatory factors for poor work ability were the number of chronic diseases, age and employment status. Solvent exposure was a weak independent risk factor for reduced WAS, comparable to a level of high alcohol consumption. Even if memory and concentration symptoms were associated with higher solvent exposure, the effect of solvents on self

Recent Advances in Anhydrous Solvents for CO2 Capture: Ionic Liquids, Switchable Solvents, and Nanoparticle Organic Hybrid Materials

International Nuclear Information System (INIS)

Park, Youngjune; Lin, Kun-Yi Andrew; Park, Ah-Hyung Alissa; Petit, Camille

2015-01-01

CO 2 capture by amine scrubbing, which has a high CO 2 capture capacity and a rapid reaction rate, is the most employed and investigated approach to date. There are a number of recent large-scale demonstrations including the Boundary Dam Carbon Capture Project by SaskPower in Canada that have reported successful implementations of aqueous amine solvent in CO 2 capture from flue gases. The findings from these demonstrations will significantly advance the field of CO 2 capture in the coming years. While the latest efforts in aqueous amine solvents are exciting and promising, there are still several drawbacks to amine-based CO 2 capture solvents including high volatility and corrosiveness of the amine solutions as well as the high parasitic energy penalty during the solvent regeneration step. Thus, in a parallel effort, alternative CO 2 capture solvents, which are often anhydrous, have been developed as the third-generation CO 2 capture solvents. These novel classes of liquid materials include ionic liquids, CO 2 -triggered switchable solvents (i.e., CO 2 -binding organic liquids, reversible ionic liquids), and nanoparticle organic hybrid materials. This paper provides a review of these various anhydrous solvents and their potential for CO 2 capture. Particular attention is given to the mechanisms of CO 2 absorption in these solvents, their regeneration and their processability – especially taking into account their viscosity. While not intended to provide a complete coverage of the existing literature, this review aims at pointing the major findings reported for these new classes of CO 2 capture media.

Structural transition of a homopolymer in solvents mixture

Energy Technology Data Exchange (ETDEWEB)

Guettari, Moez [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 Tunisia (Tunisia)], E-mail: gtarimoez@yahoo.fr; Aschi, Adel; Gomati, Riadh; Gharbi, Abdelhafidh [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 Tunisia (Tunisia)

2008-07-01

The present work is aimed at studying the thermodynamic behaviour of a polymer in solvents mixture. Dynamic light scattering is used to measure the hydrodynamic radius of polyvinylpyrrolidone (M{sub w} = 360,000 g/mol), in water/methanol solvents mixture, versus the mixed solvents composition at 25 deg. C. Then, we show that the polymer conformation adopts the Coil-Globule-Coil structure when the methanol molar fraction X{sub A} is varied. This transition is attributed to solvent quality change which result from water and methanol complex formation. The polymer contraction rate calculated for each composition takes its maximum value at X{sub A} = 0.17. Hildebrand theory assuming the solvents mixture as an equivalent solvent was used to analyze the change in mixed solvents quality. These changes can be attributed to dispersive forces in solvents mixture.

Quantitation of buried contamination by use of solvents. [degradation of silicone polymers by amine solvents

Science.gov (United States)

Pappas, S. P.; Hsiao, Y. C.; Hill, L. W.

1973-01-01

Spore recovery form cured silicone potting compounds using amine solvents to degrade the cured polymers was investigated. A complete list of solvents and a description of the effect of each on two different silicone polymers is provided.

Solvent-vapor-assisted imprint lithography

NARCIS (Netherlands)

Voicu, Nicoleta E.; Ludwigs, Sabine; Crossland, Edward J. W.; Andrew, Piers; Steiner, Ullrich

2007-01-01

Sub-micrometer features are replicated into high-molecular-weight polymer resists by using solvent-assisted nanoimprint lithography (see figure). By swelling the polymer in a controlled solvent-vapor atmosphere, millibar pressures and ambient temperatures are sufficient to achieve high-fidelity

Diluent effects in solvent extraction. The Effects of Diluents in Solvent Extraction - a literature study

International Nuclear Information System (INIS)

Loefstroem-Engdahl, Elin; Aneheim, Emma; Ekberg, Christian; Foreman, Mark; Skarnemark, Gunnar

2010-01-01

The fact that the choice of organic diluent is important for a solvent extraction process goes without saying. Several factors, such as e.g. price, flash point, viscosity, polarity etc. each have their place in the planning of a solvent extraction system. This high number of variables makes the lack of compilations concerning diluent effects to an interesting topic. Often the interest for the research concerning a specific extraction system focuses on the extractant used and the complexes built up during an extraction. The diluents used are often classical ones, even if it has been shown that choice of diluent can affect extraction as well as separation in an extraction system. An attempt to point out important steps in the understanding of diluent effects in solvent extraction is here presented. This large field is, of course, not summarized in this article, but an attempt is made to present important steps in the understanding of diluents effects in solvent extraction. Trying to make the information concerning diluent effects and applications more easily accessible this review offers a selected summarizing of literature concerning diluents effects in solvent extraction. (authors)

Effect of solvent polarity and temperature on the spectral and thermodynamic properties of exciplexes of 1-cyanonaphthalene with hexamethylbenzene in organic solvents

Energy Technology Data Exchange (ETDEWEB)

Asim, Sadia [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad (Pakistan); Mansha, Asim [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Department of Chemistry, Government College University, Faisalabad (Pakistan); Grampp, Günter, E-mail: grampp@tugraz.at [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Landgraf, Stephan [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Zahid, Muhammad [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad (Pakistan); Bhatti, Ijaz Ahmad [Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad (Pakistan)

2014-09-15

Study of the effect of solvent polarity and temperature is done on the exciplex emission spectra of 1-cyanonaphthalene with hexamethylbenzene. Exciplex system is studied in the range of partially polar solvents and in solvent mixture of propyl acetate and butyronitrile. The unique feature of this solvent mixture is that only the solvent polarity changes (6.0≤ε{sub s}≤24.7) with the change in the mole fraction of solvents whereas the solvent viscosity and refractive index remains unaffected. Thermodynamic properties are calculated according to the models developed by Weller and Kuzmin. Fluorescence lifetimes for both the fluorophore as well as the exciplex are evaluated in all used solvents. Exciplex energetics as a function of solvent polarity and temperature are also discussed. Kuzmin model of self-consistent polarization is used for the explanation of the exciplex emission spectra. The effects of solvent polarity and temperature on energy of zero–zero transitions (hv{sub 0}{sup /}), Huang–Rhys factor (S), Gauss broadening of vibronic level (σ) and the dominant high-frequency vibration (hν{sub ν}) are investigated. The strong dependence of exciplex stability and energetics upon the solvent polarity and temperature are observed. Full charge transfer exciplexes were observed in solvents of all polarities and stronger exciplex with large emission intensities were found in solvents of low polarities but with the increase in solvent polarity the exciplex becomes weak and they dissociate fastly into radical ion pairs. The kinetic model of Kuzmin was observed to reduce into the Weller kinetic model for this exciplex system with ∆G{sub ET} = −0.22 eV and the spectral shift, h∆ν>0.2 eV. - Highlights: • Exciplex formed as a result of mixing of charge transfer and locally excited states. • Effect of solvents polarity and temperature on the exciplex stability and thermodynamics. • Solvent polarity will decide the formation of contact radical ion pair

Solvent extraction studies of RERTR silicide fuels

International Nuclear Information System (INIS)

Gouge, Anthony P.

1983-01-01

Uranium silicide fuels, which are candidate RERTR fuel compositions, may require special considerations in solvent extraction reprocessing. Since Savannah River Plant may be reprocessing RERTR fuels as early as 1985, studies have been conducted at Savannah River Laboratory to demonstrate the solvent extraction behavior of this fuel. Results of solvent extraction studies with both unirradiated and irradiated fuel are presented along with the preliminary RERTR solvent extraction reprocessing flow sheet for Savannah River Plant. (author)

Studies of the reactions of uranium pentabromide and hexabromouranate(V) in non-aqueous solvents

International Nuclear Information System (INIS)

Dehos, R.F.

1984-01-01

With the help of IR and electron spectra, the behaviour of uranium pentabromide and hexabromo uranate in non-aqueous nitromethane, nitroethane, bromine, dichlormethane, dibromomethane and acetonitrile was studied. By comparison of the spectra of the solutions in nitromethane with the solutions using other solvents on one side, and on the other side with the solids spectra of the end products, the redox reactions of the uranium V in nitromethane solutions could be more than clarified. Studies were also carried out on the time-dependency of the uranium IV and uranium V contents of the solutions at room temperature and at -20 0 C. The existence of the HUBr 6 which probably appears as an intermediate product was tested in another experiment. First evidence for the existence of UBr 6 as a disproportionation product of UBr 5 were achieved by tests in solutions of acetonitrile at -47 0 C. (RB) [de

Canyon solvent cleaning with activated alumina

International Nuclear Information System (INIS)

Reif, D.J.

1987-01-01

This paper presents recent work at SRL concerning the cleaning of solvent extraction solvent used at SRP. The paper explains why we undertook the work, and some laboratory studies on two approaches to solvent cleaning, namely extended carbonate washing and use of solid adsorbents. The paper then discusses scale-up of the preferred method and the results of the full-scale cleaning. 19 figs

Bio-refinery system in a pulp mill for methanol production with comparison of pressurized black liquor gasification and dry gasification using direct causticization

International Nuclear Information System (INIS)

Naqvi, Muhammad; Yan, Jinyue; Dahlquist, Erik

2012-01-01

Black liquor gasification (BLG) for bio-fuel or electricity production at the modern pulp mills is a field in continuous evolution and the efforts are considerably driven by the climate change, fuel security, and renewable energy. This paper evaluates and compares two BLG systems for methanol production: (i) oxygen blown pressurized thermal BLG; and (ii) dry BLG with direct causticization, which have been regarded as the most potential technology candidates for the future deployment. A key objective is to assess integration possibilities of BLG technologies with the reference Kraft pulp mill producing 1000 air dried tonnes (ADt) pulp/day replacing conventional recovery cycle. The study was performed to compare the systems’ performance in terms of potential methanol production, energy efficiency, and potential CO 2 reductions. The results indicate larger potential of black liquor conversion to methanol from the pressurized BLG system (about 77 million tonnes/year of methanol) than the dry BLG system (about 30 million tonnes/year of methanol) utilizing identical amount of black liquor available worldwide (220 million tDS/year). The potential CO 2 emissions reduction from the transport sector is substantially higher in pressurized BLG system (117 million tonnes/year CO 2 reductions) as compared to dry BLG system (45 million tonnes/year CO 2 reductions). However, the dry BLG system with direct causticization shows better results when considering consequences of additional biomass import. In addition, comparison of methanol production via BLG with other bio-refinery products, e.g. hydrogen, dimethyl ether (DME) and bio-methane, has also been discussed.

Recent Advances in Anhydrous Solvents for CO2 Capture: Ionic Liquids, Switchable Solvents, and Nanoparticle Organic Hybrid Materials

Directory of Open Access Journals (Sweden)

YOUNGJUNE ePARK

2015-10-01

Full Text Available CO2 capture by amine scrubbing, which has a high CO2 capture capacity and a rapid reaction rate, is the most employed and investigated approach to date. There are a number of recent large-scale demonstrations including the Boundary Dam Carbon Capture Project by SaskPower in Canada that have reported successful implementations of aqueous amine solvent in CO2 capture from flue gases. The findings from these demonstrations will significantly advance the field of CO2 capture in the coming years. While the latest efforts in aqueous amine solvents are exciting and promising, there are still several drawbacks to amine-based CO2 capture solvents including high volatility and corrosiveness of the amine solutions, as well as the high parasitic energy penalty during the solvent regeneration step. Thus, in a parallel effort, alternative CO2 capture solvents, which are often anhydrous, have been developed as the third-generation CO2 capture solvents. These novel classes of liquid materials include: Ionic Liquids (ILs, CO2-triggered switchable solvents (i.e., CO2 Binding Organic Liquids (CO2BOLs, Reversible Ionic Liquids (RevILs, and Nanoparticle Organic Hybrid Materials (NOHMs. This paper provides a review of these various anhydrous solvents and their potential for CO2 capture. Particular attention is given to the mechanisms of CO2 absorption in these solvents, their regeneration and their processability – especially taking into account their viscosity. While not intended to provide a complete coverage of the existing literature, this review aims at pointing the major findings reported for these new classes of CO2 capture media.

Hazardous solvent substitution

International Nuclear Information System (INIS)

Twitchell, K.E.

1995-01-01

Eliminating hazardous solvents is good for the environment, worker safety, and the bottom line. However, even though we are motivated to find replacements, the big question is 'What can we use as replacements for hazardous solvents?'You, too, can find replacements for your hazardous solvents. All you have to do is search for them. Search through the vendor literature of hundreds of companies with thousands of products. Ponder the associated material safety data sheets, assuming of course that you can obtain them and, having obtained them, that you can read them. You will want to search the trade magazines and other sources for product reviews. You will want to talk to users about how well the product actually works. You may also want to check US Environmental Protection Agency (EPA) and other government reports for toxicity and other safety information. And, of course, you will want to compare the product's constituent chemicals with the many hazardous constituency lists to ensure the safe and legal use of the product in your workplace

Recent solvent extraction experience at Savannah River

International Nuclear Information System (INIS)

Gray, L.W.; Burney, G.A.; Gray, J.H.; Hodges, M.E.; Holt, D.L.; Macafee, I.M.; Reif, D.J.; Shook, H.E.

1986-01-01

Tributyl phosphate-based solvent extraction processes have been used at Savannah River for more than 30 years to separate and purify thorium, uranium, neptunium, plutonium, americium, and curium isotopes. This report summarizes the advancement of solvent extraction technology at Savannah River during the 1980's. Topics that are discussed include equipment improvements, solvent treatment, waste reduction, and an improved understanding of the various chemistries in the process streams entering, within, and leaving the solvent extraction processes

Effects of temperature and solvent concentration on the solvent crystallization of palm-based dihydroxystearic acid with isopropyl alcohol

Institute of Scientific and Technical Information of China (English)

Gregory F.L.Koay; Teong-Guan Chuah; Sumaiya Zainal-Abidin; Salmiah Ahmad; Thomas S.Y.Choong

2012-01-01

Palm-based dihydroxystearic acid of 69.55％ purity was produced in a 500-kg-per-batch operation pilot plant and purified through solvent crystallization in a custom fabricated simultaneous batch crystallizer unit.The effects of temperature and solvent concentration on yield,particle size distribution and purity were studied.The purity was higher,while the yield and particle size were lower and smaller,respectively,at higher temperature and solvent concentration.The solvent crystallization process efficiency was rated at 66-69％ when carried out with 70-80％ isopropyl alcohol at 20 ℃.

Solvents interactions with thermochromic print

Directory of Open Access Journals (Sweden)

Mirela Rožić

2017-12-01

Full Text Available In this study, the interactions between different solvents (benzene, acetone, cyclohexanone, various alcohols and water and thermochromic printing ink were investigated. Thermochromic printing ink was printed on metal surface. Components of thermochromic printing inks are polymeric microcapsules and classic yellow offset printing ink. Below its activation temperature, dye and developer within the microcapsules form a blue coloured complex. Therefore, thermochromic print is green. By heating above the activation temperature, blue colour of the complex turns into the leuco dye colourless state and the green colour of the prints turns into the yellow colour of the classic offset pigment. The results of the interaction with various solvents show that the thermochromic print is stable in all tested solvents except in ethanol, acetone and cyclohexanone. In ethanol, the green colour of the print becomes yellow. SEM analysis shows that microcapsules are dissolved. In acetone and cyclohexanone, the green colour of the print turns into blue, and the microcapsules become significantly more visible. Thus, the yellow pigment interacts with examined ketones. Based on the obtained interactions it can be concluded that the microcapsules have more polar nature than the classical pigment particles. Solvent-thermocromic print interactions were analysed using Hansen solubility parameters that rank the solvents based on their estimated interaction capabilities.

PARIS II: Computer Aided Solvent Design for Pollution Prevention

Science.gov (United States)

This product is a summary of U.S. EPA researchers' work developing the solvent substitution software tool PARIS II (Program for Assisting the Replacement of Industrial Solvents, version 2.0). PARIS II finds less toxic solvents or solvent mixtures to replace more toxic solvents co...

Organic solvents in electromembrane extraction: recent insights

DEFF Research Database (Denmark)

Huang, Chuixiu; Gjelstad, Astrid; Pedersen-Bjergaard, Stig

2016-01-01

the introduction. Under the influence of an electrical field, EME is based on electrokinetic migration of the analytes through a supported liquid membrane (SLM), which is an organic solvent immobilized in the pores of the polymeric membrane, and into the acceptor solution. Up to date, close to 150 research...... articles with focus on EME have been published. The current review summarizes the performance of EME with different organic solvents and discusses several criteria for efficient solvents in EME. In addition, the authors highlight their personal perspective about the most promising organic solvents for EME...... and have indicated that more fundamental work is required to investigate and discover new organic solvents for EME....

Dendritic brushes under theta and poor solvent conditions

Science.gov (United States)

Gergidis, Leonidas N.; Kalogirou, Andreas; Charalambopoulos, Antonios; Vlahos, Costas

2013-07-01

The effects of solvent quality on the internal stratification of polymer brushes formed by dendron polymers up to third generation were studied by means of molecular dynamics simulations with Langevin thermostat. The distributions of polymer units, of the free ends, the radii of gyration, and the back folding probabilities of the dendritic spacers were studied at the macroscopic states of theta and poor solvent. For high grafting densities we observed a small decrease in the height of the brush as the solvent quality decreases. The internal stratification in theta solvent was similar to the one we found in good solvent, with two and in some cases three kinds of populations containing short dendrons with weakly extended spacers, intermediate-height dendrons, and tall dendrons with highly stretched spacers. The differences increase as the grafting density decreases and single dendron populations were evident in theta and poor solvent. In poor solvent at low grafting densities, solvent micelles, polymeric pinned lamellae, spherical and single chain collapsed micelles were observed. The scaling dependence of the height of the dendritic brush at high density brushes for both solvents was found to be in agreement with existing analytical results.

40 CFR Table 3 to Subpart Pppp of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the... solvent blend matches both the name and CAS number for an entry, that entry's organic HAP mass fraction...

40 CFR 52.254 - Organic solvent usage.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Organic solvent usage. 52.254 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.254 Organic solvent usage. (a) This... (d) of this section and the architectural coatings and solvent disposal emission limitations...

27 CFR 21.125 - Rubber hydrocarbon solvent.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Rubber hydrocarbon solvent. 21.125 Section 21.125 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU....125 Rubber hydrocarbon solvent. (a) Rubber hydrocarbon solvent is a petroleum derivative. (b...

Pretreatment Engineering Platform (PEP) Integrated Test B Run Report--Caustic and Oxidative Leaching in UFP-VSL-T02A

Energy Technology Data Exchange (ETDEWEB)

Geeting, John GH; Bredt, Ofelia P.; Burns, Carolyn A.; Golovich, Elizabeth C.; Guzman-Leong, Consuelo E.; Josephson, Gary B.; Kurath, Dean E.; Sevigny, Gary J.; Aaberg, Rosanne L.

2009-12-10

Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed, constructed and operated as part of a plan to respond to issue M12, “Undemonstrated Leaching Processes” of the External Flowsheet Review Team (EFRT) issue response plan.( ) The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. The PEP also includes non-prototypic ancillary equipment to support the core processing.

The spectral properties of (--epigallocatechin 3-O-gallate (EGCG fluorescence in different solvents: dependence on solvent polarity.

Directory of Open Access Journals (Sweden)

Vladislav Snitsarev

Full Text Available (--Epigallocatechin 3-O-gallate (EGCG a molecule found in green tea and known for a plethora of bioactive properties is an inhibitor of heat shock protein 90 (HSP90, a protein of interest as a target for cancer and neuroprotection. Determination of the spectral properties of EGCG fluorescence in environments similar to those of binding sites found in proteins provides an important tool to directly study protein-EGCG interactions. The goal of this study is to examine the spectral properties of EGCG fluorescence in an aqueous buffer (AB at pH=7.0, acetonitrile (AN (a polar aprotic solvent, dimethylsulfoxide (DMSO (a polar aprotic solvent, and ethanol (EtOH (a polar protic solvent. We demonstrate that EGCG is a highly fluorescent molecule when excited at approximately 275 nm with emission maxima between 350 and 400 nm depending on solvent. Another smaller excitation peak was found when EGCG is excited at approximately 235 nm with maximum emission between 340 and 400 nm. We found that the fluorescence intensity (FI of EGCG in AB at pH=7.0 is significantly quenched, and that it is about 85 times higher in an aprotic solvent DMSO. The Stokes shifts of EGCG fluorescence were determined by solvent polarity. In addition, while the emission maxima of EGCG fluorescence in AB, DMSO, and EtOH follow the Lippert-Mataga equation, its fluorescence in AN points to non-specific solvent effects on EGCG fluorescence. We conclude that significant solvent-dependent changes in both fluorescence intensity and fluorescence emission shifts can be effectively used to distinguish EGCG in aqueous solutions from EGCG in environments of different polarity, and, thus, can be used to study specific EGCG binding to protein binding sites where the environment is often different from aqueous in terms of polarity.

40 CFR Table 3 to Subpart Mmmm of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Part 63—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction.... If a solvent blend matches both the name and CAS number for an entry, that entry's organic HAP mass...

Separation by solvent extraction

International Nuclear Information System (INIS)

Holt, C.H. Jr.

1976-01-01

In a process for separating fission product values from U and Pu values contained in an aqueous solution, an oxidizing agent is added to the solution to secure U and Pu in their hexavalent state. The aqueous solution is contacted with a substantially water-immiscible organic solvent with agitation while the temperature is maintained at from -1 to -2 0 C until the major part of the water present is frozen. The solid ice phase is continuously separated as it is formed and a remaining aqueous liquid phase containing fission product values and a solvent phase containing Pu and U values are separated from each other. The last obtained part of the ice phase is melted and added to the separated liquid phase. The resulting liquid is treated with a new supply of solvent whereby it is practically depleted of U and Pu

Molecular Thermodynamic Modeling of Mixed Solvent Solubility

DEFF Research Database (Denmark)

Ellegaard, Martin Dela; Abildskov, Jens; O’Connell, John P.

2010-01-01

A method based on statistical mechanical fluctuation solution theory for composition derivatives of activity coefficients is employed for estimating dilute solubilities of 11 solid pharmaceutical solutes in nearly 70 mixed aqueous and nonaqueous solvent systems. The solvent mixtures range from...... nearly ideal to strongly nonideal. The database covers a temperature range from 293 to 323 K. Comparisons with available data and other existing solubility methods show that the method successfully describes a variety of observed mixed solvent solubility behaviors using solute−solvent parameters from...

Solvent distillations studies for a reprocessing plant

International Nuclear Information System (INIS)

Ginisty, C.; Guillaume, B.

1989-01-01

The substantial amounts of solvent used in large reprocessing plants are such that considerable care must be paid to solvent management to limit the production of organic wastes. The installation of intensive treatment by chemical regeneration serves to increase the service life of the solvent. General solvent management, combined with a distillation unit under reduced pressure also helps to recycle the two components of the solvent at a low activity level. Distillation also serves to remove the heavy degradation products that are generally responsible for poor hydraulic behavior and for the holdup of radioactive products such as plutonium, zirconium and ruthenium. From the safety standpoint, the flashpoint of the distilled diluent tends to rise. It can therefore be recycled without risk

New Technology for Corrosion Mitigation of Steam Generator Tubesheet in Secondary Side Environments

International Nuclear Information System (INIS)

Hur, Do Haeng; Choi, Myung Sik; Lee, Deok Hyun; Han, Jung Ho

2013-01-01

Denting has been mitigated by a modification of the design and material of the tube support structures, it has been an inevitable problem in the crevice region of the top of the tubesheet(TTS). Denting at the TTS has been a significant concern regardless of the tube materials. This is because it is a mechanical process resulted from a volume expansion of corrosion products of the tubesheet materials. It should be noted that the corrosion rate of low alloy tubesheet materials is accelerated due to the presence of corrosion products accumulated at the top of the tubesheet. Therefore a reduction of the corrosion rate of the tubesheet material should be a key strategy to prevent tube denting at the TTS as well as an improvement of the secondary water chemistry. This paper provides a new technology to prevent denting by cladding the secondary side surface of the tubesheet with a corrosion resistant material. In this study, Alloy 690 material on the surface of the SA508 tubesheet was cladded to a thickness of about 9mm. The corrosion rates of the SA508 original tubesheet and Alloy 690 clad material were measured in acidic and caustic simulated environments. Denting has been a precursor of stress corrosion cracking in nuclear steam generator tubing, although it may be mitigated by a design and material modification of the tube support structures and secondary water chemistry control. Corrosion resistant Alloy 690 tubing is not an exception because denting at the TTS is due to corrosion of the tubesheet material. In this paper, a new technology was suggested to prevent denting at the TTS by cladding the secondary side surface of the tubesheet with a corrosion resistant material. It was verified that the corrosion rates of a tubesheet with an Alloy 690 clad layer drastically decreased in both acidic and alkaline environments, even inside the magnetite sludge pile. Because the cladding processes of Alloy 690 have already been applied to the primary side surface of a

Handbook of organic solvent properties

CERN Document Server

Smallwood, Ian

2012-01-01

The properties of 72 of the most commonly used solvents are given, tabulated in the most convenient way, making this book a joy for industrial chemists to use as a desk reference. The properties covered are those which answer the basic questions of: Will it do the job? Will it harm the user? Will it pollute the air? Is it easy to handle? Will it pollute the water? Can it be recovered or incinerated? These are all factors that need to be considered at the early stages of choosing a solvent for a new product or process.A collection of the physical properties of most commonly used solvents, their

Multiple sclerosis and organic solvents

DEFF Research Database (Denmark)

Mortensen, J T; Brønnum-Hansen, Henrik; Rasmussen, K

1998-01-01

We investigated a possible causal relation between exposure to organic solvents in Danish workers (housepainters, typographers/printers, carpenters/cabinetmakers) and onset of multiple sclerosis. Data on men included in the Danish Multiple Sclerosis Register (3,241 men) were linked with data from......, and butchers. Over a follow-up period of 20 years, we observed no increase in the incidence of multiple sclerosis among men presumed to be exposed to organic solvents. It was not possible to obtain data on potential confounders, and the study design has some potential for selection bias. Nevertheless......, the study does not support existing hypotheses regarding an association between occupational exposure to organic solvents and multiple sclerosis....

Corrosion problems in light water nuclear reactors

International Nuclear Information System (INIS)

Berry, W.E.

1984-01-01

The corrosion problems encountered during the author's career are reviewed. Attention is given to the development of Zircaloys and attendant factors that affect corrosion; the caustic and chloride stress corrosion cracking (SCC) of austenitic stainless steel steam generator tubing; the qualification of Inconel Alloy 600 for steam generator tubing and the subsequent corrosion problem of secondary side wastage, caustic SCC, pitting, intergranular attack, denting, and primary side SCC; and SCC in weld and furnace sensitized stainless steel piping and internals in boiling water reactor primary coolants. Also mentioned are corrosion of metallic uranium alloy fuels; corrosion of aluminum and niobium candidate fuel element claddings; crevice corrosion and seizing of stainless steel journal-sleeve combinations; SCC of precipitation hardened and martensitic stainless steels; low temperature SCC of welded austenitic stainless steels by chloride, fluoride, and sulfur oxy-anions; and corrosion problems experienced by condensers

Systematic Assessment of Seven Solvent and Solid-Phase Extraction Methods for Metabolomics Analysis of Human Plasma by LC-MS

Science.gov (United States)

Sitnikov, Dmitri G.; Monnin, Cian S.; Vuckovic, Dajana

2016-12-01

The comparison of extraction methods for global metabolomics is usually executed in biofluids only and focuses on metabolite coverage and method repeatability. This limits our detailed understanding of extraction parameters such as recovery and matrix effects and prevents side-by-side comparison of different sample preparation strategies. To address this gap in knowledge, seven solvent-based and solid-phase extraction methods were systematically evaluated using standard analytes spiked into both buffer and human plasma. We compared recovery, coverage, repeatability, matrix effects, selectivity and orthogonality of all methods tested for non-lipid metabolome in combination with reversed-phased and mixed-mode liquid chromatography mass spectrometry analysis (LC-MS). Our results confirmed wide selectivity and excellent precision of solvent precipitations, but revealed their high susceptibility to matrix effects. The use of all seven methods showed high overlap and redundancy which resulted in metabolite coverage increases of 34-80% depending on LC-MS method employed as compared to the best single extraction protocol (methanol/ethanol precipitation) despite 7x increase in MS analysis time and sample consumption. The most orthogonal methods to methanol-based precipitation were ion-exchange solid-phase extraction and liquid-liquid extraction using methyl-tertbutyl ether. Our results help facilitate rational design and selection of sample preparation methods and internal standards for global metabolomics.

Performance of thermal solvent process in Athabasca reservoir

Energy Technology Data Exchange (ETDEWEB)

Das, Swapan [Marathon Oil (Canada)

2011-07-01

In the petroleum industry, due to depletion of conventional resources and high demand operators are looking into heavy oil and bitumen production. Different recovery methods exist, some of them based on heating the reservoir and others on the use of solvent. Thermal solvent process is a combination of both: a small amount of heat is used to maintain a solvent vapor phase in the reservoir. This process has advantages, solvent is mostly recycled which increases bitumen recovery efficiency and reduces the need for fresh solvent, but it also poses challenges, such as maintaining a vapor chamber and the fact that solvent solubility might be affected by heating. The aim of this paper is to discuss these issues. Simulations and field tests were conducted on bitumen in the the Athabasca region. This paper presented a thermal solvent process and its application's results in Athabasca reservoir.

Steam generator secondary side chemical cleaning at Gentilly-2

International Nuclear Information System (INIS)

Plante, S.

2006-01-01

After more than 20 years of operation, the secondary side of the four steam generators at Gentilly-2 were chemically cleaned during the 2005 annual outage. The FRAMATOME ANP high temperature cleaning process used to remove magnetite loading involved stepwise injection of solvent with PHT temperature in the range 160 o C to 175 o C. The heat required to maintain the PHT temperature was provided by the operation of the main PHT pumps and the reactor core residual heat. The temperature control was accomplished by the shutdown cooling system heat exchangers. A total of 1280 kg of magnetite was removed from the four steam generators. A copper-cleaning step was applied after the iron step. The PHT has been cooled down and the steam generators drained to temporary tanks and dried in preparation of the copper step. The process has been applied at room temperature, two boilers at a time. The solvent removed a total of 116 kg of copper. During the iron step, steam flow to the feedwater tank chemically contaminate the Balance Of Plant (BOP) systems. The isolation of this path should have been part of the G2 procedures. Around 700 m3 of water had to be drained to interim storage tanks for subsequent resin treatment before disposal. Visual inspection of BO1 tubesheet and first support plate showed clean surfaces without measurable sludge pile. Upper support plates visual inspection of BO4 revealed that broach holes blockage reported in 2000 is still present in peripheral area. Following the plant restart, the medium range level measurement instability observed since several years for BO3 was no more present. As anticipated, it also has been observed that the medium and wide range level measurements have shifted down as a result of downcomer flow increase after the cleaning. The cleaning objectives were achieved regarding the fouling reduction on the steam generators secondary side but broach holes blockage of the upper support plate is still present in periphery. (author)

Accumulation of solvent-soluble and solvent-insoluble antioxidant phenolics in edible bean sprouts: implication of germination

Directory of Open Access Journals (Sweden)

Ren-You Gan

2016-08-01

Full Text Available Background: Edible bean sprouts are popular fresh vegetables widely recognized for their nutritional quality. However, while their antioxidant capacity and phenolic composition in both solvent-soluble and solvent-insoluble extracts has not been systematically evaluated. Methods: The antioxidant capacity and phenolic composition in both solvent-soluble and solvent-insoluble fractions of 12 cultivars of edible bean sprouts were evaluated, and relationships of antioxidant capacity and total phenolic content were also analyzed. Results: Sprouts demonstrated a wide range of antioxidant capacity and total phenolic content, with lower but substantial antioxidant capacity and total phenolic content in the solvent-insoluble fractions. Highest levels were found in the green mung bean sprout. Phenolic compounds, such as catechin, ellagic acid, ferulic acid, gallic acid and p-coumaric acid were widely detected in these sprouts. Additionally, a positive correlation was discovered between antioxidant capacity and total phenolic content in these edible bean sprouts. Conclusions: Germination generally resulted in the accumulation of antioxidant phenolics in the most edible bean sprouts. Edible bean sprouts with high antioxidant phenolics can be valuable natural sources of dietary antioxidants for the prevention of oxidative stress-related chronic diseases.

Green solvents and technologies for oil extraction from oilseeds.

Science.gov (United States)

Kumar, S P Jeevan; Prasad, S Rajendra; Banerjee, Rintu; Agarwal, Dinesh K; Kulkarni, Kalyani S; Ramesh, K V

2017-01-01

Oilseeds are crucial for the nutritional security of the global population. The conventional technology used for oil extraction from oilseeds is by solvent extraction. In solvent extraction, n -hexane is used as a solvent for its attributes such as simple recovery, non-polar nature, low latent heat of vaporization (330 kJ/kg) and high selectivity to solvents. However, usage of hexane as a solvent has lead to several repercussions such as air pollution, toxicity and harmfulness that prompted to look for alternative options. To circumvent the problem, green solvents could be a promising approach to replace solvent extraction. In this review, green solvents and technology like aqueous assisted enzyme extraction are better solution for oil extraction from oilseeds. Enzyme mediated extraction is eco-friendly, can obtain higher yields, cost-effective and aids in obtaining co-products without any damage. Enzyme technology has great potential for oil extraction in oilseed industry. Similarly, green solvents such as terpenes and ionic liquids have tremendous solvent properties that enable to extract the oil in eco-friendly manner. These green solvents and technologies are considered green owing to the attributes of energy reduction, eco-friendliness, non-toxicity and non-harmfulness. Hence, the review is mainly focussed on the prospects and challenges of green solvents and technology as the best option to replace the conventional methods without compromising the quality of the extracted products.

Compound forming extractants, solvating solvents and inert solvents IUPAC chemical data series

CERN Document Server

Marcus, Y; Kertes, A S

2013-01-01

Equilibrium Constants of Liquid-Liquid Distribution Reactions, Part III: Compound Forming Extractants, Solvating Solvents, and Inert Solvents focuses on the compilation of equilibrium constants of various compounds, such as acids, ions, salts, and aqueous solutions. The manuscript presents tables that show the distribution reactions of carboxylic and sulfonic acid extractants and their dimerization and other reactions in the organic phase and extraction reactions of metal ions from aqueous solutions. The book also states that the inorganic anions in these solutions are irrelevant, since they d

Batch extracting process using magnetic particle held solvents

Science.gov (United States)

Nunez, L.; Vandergrift, G.F.

1995-11-21

A process is described for selectively removing metal values which may include catalytic values from a mixture containing same, wherein a magnetic particle is contacted with a liquid solvent which selectively dissolves the metal values to absorb the liquid solvent onto the magnetic particle. Thereafter the solvent-containing magnetic particles are contacted with a mixture containing the heavy metal values to transfer metal values into the solvent carried by the magnetic particles, and then magnetically separating the magnetic particles. Ion exchange resins may be used for selective solvents. 5 figs.

Recent Advances in Anhydrous Solvents for CO{sub 2} Capture: Ionic Liquids, Switchable Solvents, and Nanoparticle Organic Hybrid Materials

Energy Technology Data Exchange (ETDEWEB)

Park, Youngjune [School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju (Korea, Republic of); Lin, Kun-Yi Andrew [Department of Environmental Engineering, National Chung Hsing University, Taichung City (China); Park, Ah-Hyung Alissa, E-mail: ap2622@columbia.edu [Department of Earth and Environmental Engineering, Lenfest Center for Sustainable Energy, Columbia University, New York, NY (United States); Department of Chemical Engineering, Lenfest Center for Sustainable Energy, Columbia University, New York, NY (United States); Petit, Camille, E-mail: ap2622@columbia.edu [Department of Chemical Engineering, Imperial College London, London (United Kingdom)

2015-10-01

CO{sub 2} capture by amine scrubbing, which has a high CO{sub 2} capture capacity and a rapid reaction rate, is the most employed and investigated approach to date. There are a number of recent large-scale demonstrations including the Boundary Dam Carbon Capture Project by SaskPower in Canada that have reported successful implementations of aqueous amine solvent in CO{sub 2} capture from flue gases. The findings from these demonstrations will significantly advance the field of CO{sub 2} capture in the coming years. While the latest efforts in aqueous amine solvents are exciting and promising, there are still several drawbacks to amine-based CO{sub 2} capture solvents including high volatility and corrosiveness of the amine solutions as well as the high parasitic energy penalty during the solvent regeneration step. Thus, in a parallel effort, alternative CO{sub 2} capture solvents, which are often anhydrous, have been developed as the third-generation CO{sub 2} capture solvents. These novel classes of liquid materials include ionic liquids, CO{sub 2}-triggered switchable solvents (i.e., CO{sub 2}-binding organic liquids, reversible ionic liquids), and nanoparticle organic hybrid materials. This paper provides a review of these various anhydrous solvents and their potential for CO{sub 2} capture. Particular attention is given to the mechanisms of CO{sub 2} absorption in these solvents, their regeneration and their processability – especially taking into account their viscosity. While not intended to provide a complete coverage of the existing literature, this review aims at pointing the major findings reported for these new classes of CO{sub 2} capture media.

Fluoro-Carbonate Solvents for Li-Ion Cells

International Nuclear Information System (INIS)

NAGASUBRAMANIAN, GANESAN

1999-01-01

A number of fluoro-carbonate solvents were evaluated as electrolytes for Li-ion cells. These solvents are fluorine analogs of the conventional electrolyte solvents such as dimethyl carbonate, ethylene carbonate, diethyl carbonate in Li-ion cells. Conductivity of single and mixed fluoro carbonate electrolytes containing 1 M LiPF(sub 6) was measured at different temperatures. These electrolytes did not freeze at -40 C. We are evaluating currently, the irreversible 1st cycle capacity loss in carbon anode in these electrolytes and the capacity loss will be compared to that in the conventional electrolytes. Voltage stability windows of the electrolytes were measured at room temperature and compared with that of the conventional electrolytes. The fluoro-carbon electrolytes appear to be more stable than the conventional electrolytes near Li voltage. Few preliminary electrochemical data of the fluoro-carbonate solvents in full cells are reported in the literature. For example, some of the fluorocarbonate solvents appear to have a wider voltage window than the conventional electrolyte solvents. For example, methyl 2,2,2 trifluoro ethyl carbonate containing 1 M LiPF(sub 6) electrolyte has a decomposition voltage exceeding 6 V vs. Li compared to and lt;5 V for conventional electrolytes. The solvent also appears to be stable in contact with lithium at room temperature

Controlling Actinide Hydration in Mixed Solvent Systems: Towards Tunable Solvent Systems to Close the Fuel Cycle

International Nuclear Information System (INIS)

Clark, Sue B.

2016-01-01

The goal of this project has been to define the extent of hydration the f-elements and other cations in mixed solvent electrolyte systems. Methanol-water and other mixed solvent systems have been studied, where the solvent dielectric constant was varied systematically. Thermodynamic and spectroscopic studies provide details concerning the energetics of complexation and other reactions of these cations. This information has also been used to advance new understanding of the behavior of these cations in a variety of systems, ranging from environmental studies, chromatographic approaches, and ionization processes for mass spectrometry.

Controlling Actinide Hydration in Mixed Solvent Systems: Towards Tunable Solvent Systems to Close the Fuel Cycle

Energy Technology Data Exchange (ETDEWEB)

Clark, Sue B. [Washington State Univ., Pullman, WA (United States). Dept. of Chemistry

2016-10-31

The goal of this project has been to define the extent of hydration the f-elements and other cations in mixed solvent electrolyte systems. Methanol-water and other mixed solvent systems have been studied, where the solvent dielectric constant was varied systematically. Thermodynamic and spectroscopic studies provide details concerning the energetics of complexation and other reactions of these cations. This information has also been used to advance new understanding of the behavior of these cations in a variety of systems, ranging from environmental studies, chromatographic approaches, and ionization processes for mass spectrometry.

Method of decomposing radioactive organic solvent wastes

International Nuclear Information System (INIS)

Uki, Kazuo; Ichihashi, Toshio; Hasegawa, Akira; Sato, Tatsuaki

1986-01-01

Purpose: To decompose radioactive organic solvent wastes or radioactive hydrocarbon solvents separated therefrom into organic materials under moderate conditions, as well as greatly decrease the amount of secondary wastes generated. Method: Radioactive organic solvent wastes comprising an organic phosphoric acid ester ingredient and a hydrocarbon ingredient as a diluent therefor, or radioactive hydrocarbon solvents separated therefrom are oxidatively decomposed by hydrogen peroxide in an aqueous phosphoric acid solution of phosphoric acid metal salts finally into organic materials to perform decomposing treatment for the radioactive organic solvent wastes. The decomposing reaction is carried out under relatively moderate conditions and cause less burden to facilities or the likes. Further, since the decomposed liquid after the treatment can be reused for the decomposing reaction as a catalyst solution secondary wastes can significantly be decreased. (Yoshihara, H.)

Permeability of commercial solvents through living human skin

DEFF Research Database (Denmark)

Ursin, C; Hansen, C M; Van Dyk, J W

1995-01-01

A procedure has been developed for measuring the steady state rate of permeation of commercial solvents through living human skin. To get the most consistent results, it was necessary with some solvents to normalize the solvent permeation rate of a given skin sample with its [3H]water permeation...... rate. For other solvents this was not necessary, so the un-normalized data were used. High [3H]water permeation rate also was used as a criterion for "defective" skin samples that gave erroneous permeability rates, especially for solvents having slow permeability. The linearity of the steady state data...... of DMSO and octyl acetate were measured. No octyl acetate was detected and the permeability of DMSO was proportional to its mole fraction in the mixture. The effect of two hours of solvent exposure on the viability of skin (based on DNA synthesis) was measured and found to be very dependent on the solvent....

Chlorinated solvents in groundwater of the United States

Science.gov (United States)

Moran, M.J.; Zogorski, J.S.; Squillace, P.J.

2007-01-01

Four chlorinated solvents-methylene chloride, perchloroethene (PCE), 1,1,1-trichloroethane, and trichloroethene (TCE)-were analyzed in samples of groundwater taken throughout the conterminous United States by the U.S. Geological Survey. The samples were collected between 1985 and 2002 from more than 5,000 wells. Of 55 volatile organic compounds (VOCs) analyzed in groundwater samples, solvents were among the most frequently detected. Mixtures of solvents in groundwater were common and may be the result of common usage of solvents or degradation of one solvent to another. Relative to other VOCs with Maximum Contaminant Levels (MCLs), PCE and TCE ranked high in terms of the frequencies of concentrations greater than or near MCLs. The probability of occurrence of solvents in groundwater was associated with dissolved oxygen content of groundwater, sources such as urban land use and population density, and hydraulic properties of the aquifer. The results reinforce the importance of understanding the redox conditions of aquifers and the hydraulic properties of the saturated and vadose zones in determining the intrinsic susceptibility of groundwater to contamination by solvents. The results also reinforce the importance of controlling sources of solvents to groundwater. ?? 2007 American Chemical Society.

High-Performance Lithium-Oxygen Battery Electrolyte Derived from Optimum Combination of Solvent and Lithium Salt.

Science.gov (United States)

Ahn, Su Mi; Suk, Jungdon; Kim, Do Youb; Kang, Yongku; Kim, Hwan Kyu; Kim, Dong Wook

2017-10-01

To fabricate a sustainable lithium-oxygen (Li-O 2 ) battery, it is crucial to identify an optimum electrolyte. Herein, it is found that tetramethylene sulfone (TMS) and lithium nitrate (LiNO 3 ) form the optimum electrolyte, which greatly reduces the overpotential at charge, exhibits superior oxygen efficiency, and allows stable cycling for 100 cycles. Linear sweep voltammetry (LSV) and differential electrochemical mass spectrometry (DEMS) analyses reveal that neat TMS is stable to oxidative decomposition and exhibit good compatibility with a lithium metal. But, when TMS is combined with typical lithium salts, its performance is far from satisfactory. However, the TMS electrolyte containing LiNO 3 exhibits a very low overpotential, which minimizes the side reactions and shows high oxygen efficiency. LSV-DEMS study confirms that the TMS-LiNO 3 electrolyte efficiently produces NO 2 - , which initiates a redox shuttle reaction. Interestingly, this NO 2 - /NO 2 redox reaction derived from the LiNO 3 salt is not very effective in solvents other than TMS. Compared with other common Li-O 2 solvents, TMS seems optimum solvent for the efficient use of LiNO 3 salt. Good compatibility with lithium metal, high dielectric constant, and low donicity of TMS are considered to be highly favorable to an efficient NO 2 - /NO 2 redox reaction, which results in a high-performance Li-O 2 battery.

Field demonstration of in situ treatment of buried low-level radioactive solid waste with caustic soda and soda ash to immobilize 90Sr

International Nuclear Information System (INIS)

Spalding, B.P.

1984-02-01

A low-level radioactive solid waste disposal trench was injected on four occasions with solutions of caustic soda, soda ash, caustic soda, and lime/soda ash, respectively. Because investigations had indicated that 90 Sr could be coprecipitated with soil calcium carbonate by treatment with soda ash, this demonstration was undertaken as a test of its technical feasibility. After concentrations of 90 Sr and water hardness decreased within the intratrench monitoring wells; one well at the foot of the trench decreased from over 100 to a persistent level of less than 10 kBq of 90 Sr per liter. Recharge of 90 Sr from the trench to a sump immediately below was reduced by about 90%. Water hardness and 90 Sr concentrations were strongly correlated through time within each monitoring well, indicating that 90 Sr behaved as a tracer for soil calcium and magnesium. The disappearance of 90 Sr from the trench water, therefore, was an in situ water softening. Soil samples retrieved from the trench indicated that as much as 98% of the total 90 Sr was present as a coprecipitate with calcium carbonate. The hydrologic characterization of this trench indicated an average void space of 41% and an average trench-wall hydraulic conductivity of 3.4 x 10 -7 m/s. Sampling of the trench's discharge contamination plume indicated that it had resulted from a combination of subsurface seepage and bathtub overflow during infrequent periods of intense precipitation. A generic assessment of soda ash treatment indicated that treatment would be most effective for soils of high cation exchange capacity with either low ( 80%) basic cation saturation of that cation exchange capacity

Stochastic level-set variational implicit-solvent approach to solute-solvent interfacial fluctuations

Energy Technology Data Exchange (ETDEWEB)

Zhou, Shenggao, E-mail: sgzhou@suda.edu.cn, E-mail: bli@math.ucsd.edu [Department of Mathematics and Mathematical Center for Interdiscipline Research, Soochow University, 1 Shizi Street, Jiangsu, Suzhou 215006 (China); Sun, Hui; Cheng, Li-Tien [Department of Mathematics, University of California, San Diego, La Jolla, California 92093-0112 (United States); Dzubiella, Joachim [Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin, 14109 Berlin, Germany and Institut für Physik, Humboldt-Universität zu Berlin, 12489 Berlin (Germany); Li, Bo, E-mail: sgzhou@suda.edu.cn, E-mail: bli@math.ucsd.edu [Department of Mathematics and Quantitative Biology Graduate Program, University of California, San Diego, La Jolla, California 92093-0112 (United States); McCammon, J. Andrew [Department of Chemistry and Biochemistry, Department of Pharmacology, Howard Hughes Medical Institute, University of California, San Diego, La Jolla, California 92093-0365 (United States)

2016-08-07

Recent years have seen the initial success of a variational implicit-solvent model (VISM), implemented with a robust level-set method, in capturing efficiently different hydration states and providing quantitatively good estimation of solvation free energies of biomolecules. The level-set minimization of the VISM solvation free-energy functional of all possible solute-solvent interfaces or dielectric boundaries predicts an equilibrium biomolecular conformation that is often close to an initial guess. In this work, we develop a theory in the form of Langevin geometrical flow to incorporate solute-solvent interfacial fluctuations into the VISM. Such fluctuations are crucial to biomolecular conformational changes and binding process. We also develop a stochastic level-set method to numerically implement such a theory. We describe the interfacial fluctuation through the “normal velocity” that is the solute-solvent interfacial force, derive the corresponding stochastic level-set equation in the sense of Stratonovich so that the surface representation is independent of the choice of implicit function, and develop numerical techniques for solving such an equation and processing the numerical data. We apply our computational method to study the dewetting transition in the system of two hydrophobic plates and a hydrophobic cavity of a synthetic host molecule cucurbit[7]uril. Numerical simulations demonstrate that our approach can describe an underlying system jumping out of a local minimum of the free-energy functional and can capture dewetting transitions of hydrophobic systems. In the case of two hydrophobic plates, we find that the wavelength of interfacial fluctuations has a strong influence to the dewetting transition. In addition, we find that the estimated energy barrier of the dewetting transition scales quadratically with the inter-plate distance, agreeing well with existing studies of molecular dynamics simulations. Our work is a first step toward the

Process for hydrogenating coal and coal solvents

Science.gov (United States)

Tarrer, Arthur R.; Shridharani, Ketan G.

1983-01-01

A novel process is described for the hydrogenation of coal by the hydrogenation of a solvent for the coal in which the hydrogenation of the coal solvent is conducted in the presence of a solvent hydrogenation catalyst of increased activity, wherein the hydrogenation catalyst is produced by reacting ferric oxide with hydrogen sulfide at a temperature range of 260.degree. C. to 315.degree. C. in an inert atmosphere to produce an iron sulfide hydrogenation catalyst for the solvent. Optimally, the reaction temperature is 275.degree. C. Alternately, the reaction can be conducted in a hydrogen atmosphere at 350.degree. C.

COMPUTER-AIDED SOLVENT DESIGN FOR POLLUTION PREVENTION: PARIS II

Science.gov (United States)

Solvent substitution is an attractive way of elijminating the use of regulated solvents because it usually does not require major chanages in existing processes, equipment or operations. Successful solvent substitution is dependent on finding solvents that are as effective or be...

Spectroscopic and DFT study of solvent effects on the electronic absorption spectra of sulfamethoxazole in neat and binary solvent mixtures

Science.gov (United States)

Almandoz, M. C.; Sancho, M. I.; Blanco, S. E.

2014-01-01

The solvatochromic behavior of sulfamethoxazole (SMX) was investigated using UV-vis spectroscopy and DFT methods in neat and binary solvent mixtures. The spectral shifts of this solute were correlated with the Kamlet and Taft parameters (α, β and π*). Multiple lineal regression analysis indicates that both specific hydrogen-bond interaction and non specific dipolar interaction play an important role in the position of the absorption maxima in neat solvents. The simulated absorption spectra using TD-DFT methods were in good agreement with the experimental ones. Binary mixtures consist of cyclohexane (Cy)-ethanol (EtOH), acetonitrile (ACN)-dimethylsulfoxide (DMSO), ACN-dimethylformamide (DMF), and aqueous mixtures containing as co-solvents DMSO, ACN, EtOH and MeOH. Index of preferential solvation was calculated as a function of solvent composition and non-ideal characteristics are observed in all binary mixtures. In ACN-DMSO and ACN-DMF mixtures, the results show that the solvents with higher polarity and hydrogen bond donor ability interact preferentially with the solute. In binary mixtures containing water, the SMX molecules are solvated by the organic co-solvent (DMSO or EtOH) over the whole composition range. Synergistic effect is observed in the case of ACN-H2O and MeOH-H2O, indicating that at certain concentrations solvents interact to form association complexes, which should be more polar than the individual solvents of the mixture.

Solvent sorting in (mixed solvent electrolyte) systems: Time-resolved ...

Indian Academy of Sciences (India)

lar solvents as an effective single component dipo- lar liquid that is characterized ... and time (t) dependent solvation energy of mobile dipo- lar solute with density ..... Even though this way for modification of C is purely ad- hoc, the observation ...

Chemical reactions in solvents and melts

CERN Document Server

Charlot, G

1969-01-01

Chemical Reactions in Solvents and Melts discusses the use of organic and inorganic compounds as well as of melts as solvents. This book examines the applications in organic and inorganic chemistry as well as in electrochemistry. Organized into two parts encompassing 15 chapters, this book begins with an overview of the general properties and the different types of reactions, including acid-base reactions, complex formation reactions, and oxidation-reduction reactions. This text then describes the properties of inert and active solvents. Other chapters consider the proton transfer reactions in

Corrosion and cleaning aspects of sodium side crevices in components of LMFBR's

International Nuclear Information System (INIS)

Chirer, E.G.

1978-01-01

Although the presence of crevices is excluded in critical areas of sodium components by design, their occurrence in other areas cannot be eliminated completely. During the lifetime of a component high concentrations of sodium compounds, such as caustics, may be formed in crevices. These compounds can remain within the crevices for some time. In this respect the following situations are recognized: - Reaction products from initial contaminants such as oxide scales. The component with crevices containing oxide scale either from the manufacturing process or insufficient cleaning after water pressure testing is exposed to sodium during actual operation. - Reaction products formed during or after cleaning. Sodium in the crevices of a drained component reacts with water vapour or water during cleaning or during subsequent storing or handling under non-perfect conditions. Before refilling with sodium the component is heated to preheat temperature. Same situation as above, however the component is exposed to sodium at operating temperature. These cycles can be repeated several times. - Products from a small sodium-water reaction. Caustic products from a small sodium-water reaction may be present in crevices or dead ends of a component which is exposed to high temperature during sodium operation or during vacuum distillation. The aims of the investigations are: determination of the corrosive aspects of high concentration of caustic reaction products of sodium in crevices on the structural materials of the component; comparison of the effectiveness of different cleaning procedures in respect to removal of sodium from crevices, e.g. water, steam, alcohol cleaning, vacuum distillation. Concerning the first item, in particular the possibility of the occurrence of intercrystalline corrosion and stress corrosion cracking is investigated. Materials investigated are the Cr-Mo steels 2 1/4Cr1Mo stabilized with Nb, 9Cr1Mo, 12Cr1Mo and the austenitic stainless steal AISI 304. The

40 CFR 148.10 - Waste specific prohibitions-solvent wastes.

Science.gov (United States)

2010-07-01

... injection unless the solvent waste is a solvent-water mixture or solvent-containing sludge containing less... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Waste specific prohibitions-solvent wastes. 148.10 Section 148.10 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER...

Compressed air-assisted solvent extraction (CASX) for metal removal.

Science.gov (United States)

Li, Chi-Wang; Chen, Yi-Ming; Hsiao, Shin-Tien

2008-03-01

A novel process, compressed air-assisted solvent extraction (CASX), was developed to generate micro-sized solvent-coated air bubbles (MSAB) for metal extraction. Through pressurization of solvent with compressed air followed by releasing air-oversaturated solvent into metal-containing wastewater, MSAB were generated instantaneously. The enormous surface area of MSAB makes extraction process extremely fast and achieves very high aqueous/solvent weight ratio (A/S ratio). CASX process completely removed Cr(VI) from acidic electroplating wastewater under A/S ratio of 115 and extraction time of less than 10s. When synthetic wastewater containing Cd(II) of 50mgl(-1) was treated, A/S ratios of higher than 714 and 1190 could be achieved using solvent with extractant/diluent weight ratio of 1:1 and 5:1, respectively. Also, MSAB have very different physical properties, such as size and density, compared to the emulsified solvent droplets, making separation and recovery of solvent from treated effluent very easy.

Process for hydrogenating coal and coal solvents

Energy Technology Data Exchange (ETDEWEB)

Shridharani, K.G.; Tarrer, A.R.

1983-02-15

A novel process is described for the hydrogenation of coal by the hydrogenation of a solvent for the coal in which the hydrogenation of the coal solvent is conducted in the presence of a solvent hydrogenation catalyst of increased activity, wherein the hydrogenation catalyst is produced by reacting ferric oxide with hydrogen sulfide at a temperature range of 260/sup 0/ C to 315/sup 0/ C in an inert atmosphere to produce an iron sulfide hydrogenation catalyst for the solvent. Optimally, the reaction temperature is 275/sup 0/ C. Alternately, the reaction can be conducted in a hydrogen atmosphere at 350/sup 0/ C.

A computer-aided molecular design framework for crystallization solvent design

DEFF Research Database (Denmark)

Karunanithi, Arunprakash T.; Achenie, Luke E.K.; Gani, Rafiqul

2006-01-01

One of the key decisions in designing solution crystallization processes is the selection of solvents. In this paper, we present a computer-aided molecular design (CAMD) framework for the design and selection of solvents and/or anti-solvents for solution crystallization. The CAMD problem is formu......One of the key decisions in designing solution crystallization processes is the selection of solvents. In this paper, we present a computer-aided molecular design (CAMD) framework for the design and selection of solvents and/or anti-solvents for solution crystallization. The CAMD problem...... solvent molecules. Solvent design and selection for two types of solution crystallization processes namely cooling crystallization and drowning out crystallization are presented. In the first case study, the design of single compound solvent for crystallization of ibuprofen, which is an important...

Permeability of commercial solvents through living human skin

DEFF Research Database (Denmark)

Ursin, C; Hansen, C M; Van Dyk, J W

1995-01-01

A procedure has been developed for measuring the steady state rate of permeation of commercial solvents through living human skin. To get the most consistent results, it was necessary with some solvents to normalize the solvent permeation rate of a given skin sample with its [3H]water permeation...... rate. For other solvents this was not necessary, so the un-normalized data were used. High [3H]water permeation rate also was used as a criterion for "defective" skin samples that gave erroneous permeability rates, especially for solvents having slow permeability. The linearity of the steady state data...... was characterized by calculation of the "percent error of the slope." The following permeability rates (g/m2h) of single solvents were measured: dimethyl sulfoxide (DMSO), 176; N-methyl-2-pyrrolidone, 171; dimethyl acetamide, 107; methyl ethyl ketone, 53; methylene chloride, 24; [3H]water, 14.8; ethanol, 11...

Radiation destruction of vitamin A in lipid solvents

International Nuclear Information System (INIS)

Snauwaert, F.; Maes, E.; Tobback, P.; Bhushan, B.

1978-01-01

The radiation response of vitamin A alcohol and its acetate derivative was compared in different lipid solvents. In all the solvents vitamin A alcohol exhibited a much higher radiation sensitivity than its ester counterpart. The nature of the solvent and the initial concentration was found to have a great influence on the extent of radiation degradation of vitamin A alcohol. In contrast to a high radiolability in non-polar solvents, vitamin A alcohol exhibited a remarkable stability in isopropanol. In addition, in isopropanol the G(-) relationship with radiation dose showed a reverse trend to that observed for other solvents. A thin-layer chromatographic procedure was developed for separation of the radiation degradation products. (author)

Solvent extraction studies in miniature centrifugal contactors

International Nuclear Information System (INIS)

Siczek, A.A.; Meisenhelder, J.H.; Bernstein, G.J.; Steindler, M.J.

1980-01-01

A miniature short-residence-time centrifugal solvent extraction contactor and an eight-stage laboratory minibank of centrifugal contactors were used for testing the possibility of utilizing kinetic effects for improving the separation of uranium from ruthenium and zirconium in the Purex process. Results of these tests showed that a small improvement found in ruthenium and zirconium decontamination in single-stage solvent extraction tests was lost in the multistage extraction tests- in fact, the extent of saturation of the solvent by uranium, rather than the stage residence time, controlled the extent of ruthenium and zirconium extraction. In applying the centrifugal contactor to the Purex process, the primary advantages would be less radiolytic damage to the solvent, high troughput, reduced solvent inventory, and rapid attainment of steady-state operating conditions. The multistage mini contactor was also tested to determine the suitability of short-residence-time contactors for use with the Civex and Thorex processes and was found to be compatible with the requirements of these processes. (orig.) [de

Green solvents and technologies for oil extraction from oilseeds

OpenAIRE

Kumar, S. P. Jeevan; Prasad, S. Rajendra; Banerjee, Rintu; Agarwal, Dinesh K.; Kulkarni, Kalyani S.; Ramesh, K. V.

2017-01-01

Oilseeds are crucial for the nutritional security of the global population. The conventional technology used for oil extraction from oilseeds is by solvent extraction. In solvent extraction, n-hexane is used as a solvent for its attributes such as simple recovery, non-polar nature, low latent heat of vaporization (330?kJ/kg) and high selectivity to solvents. However, usage of hexane as a solvent has lead to several repercussions such as air pollution, toxicity and harmfulness that prompted to...

Spreadsheet algorithm for stagewise solvent extraction

International Nuclear Information System (INIS)

Leonard, R.A.; Regalbuto, M.C.

1994-01-01

The material balance and equilibrium equations for solvent extraction processes have been combined with computer spreadsheets in a new way so that models for very complex multicomponent multistage operations can be setup and used easily. A part of the novelty is the way in which the problem is organized in the spreadsheet. In addition, to facilitate spreadsheet setup, a new calculational procedure has been developed. The resulting Spreadsheet Algorithm for Stagewise Solvent Extraction (SASSE) can be used with either IBM or Macintosh personal computers as a simple yet powerful tool for analyzing solvent extraction flowsheets. 22 refs., 4 figs., 2 tabs

Method of removing deterioration product in hydrocarbon type solvent

International Nuclear Information System (INIS)

Ito, Yoshifumi; Takashina, Toru; Murasawa, Kenji.

1988-01-01

Purpose: To remarkably reduce radioactive wastes by bringing adsorbents comprising titanium oxide and/or zirconium oxide into contact with hydrocarbon type solvents. Method: In a nuclear fuel re-processing step, an appropriate processing is applied to extraction solvents suffering from radioactive degradation, to separate the hydrocarbon solvents and store them in a solvent tank. Then, titanium oxide and/or zirconium oxide adsorbents are continuously mixed and agitated therewith to adsorb degradation products on the adsorbents. Then, they are introduced with adsorbent separators to recover purified hydrocarbon type solvents. Meanwhile, the separated adsorbents are discharged from pipeways. This enables to regenerate the hydrocarbon type solvents for reuse, as well as remarkably reduce the radioactive wastes. (Takahashi, M.)

Physiological and skill demands of 'on-side' and 'off-side' games.

Science.gov (United States)

Gabbett, Tim J; Jenkins, David G; Abernethy, Bruce

2010-11-01

This study investigated the physiological and skill demands of 'on-side' and 'off-side' games in elite rugby league players. Sixteen male rugby league players participated in 'on-side' and 'off-side' games. Both small-sided games were played in a 40- × 40-m playing area. The 'off-side' game permitted players to have 3 'plays' while in possession of the ball. Players were permitted to pass backward or forward (to an 'off-side' player). The 'on-side' game also permitted players to have 3 'plays' while in possession of the ball. However, players were only permitted to pass backward to players in an 'on-side' position. Heart rate and movement patterns (via global positioning system) were recorded continuously throughout both games. Data were collected on the distance covered, number of high-acceleration and velocity efforts, and recovery between efforts. Video footage was also taken to track the performance of the players. Post hoc inspection of the footage was undertaken to count the number of possessions and the number and quality of disposals. In comparison to 'on-side' games, 'off-side' games had a greater number of involvements ("touches"), passes, and effective passes. However, the cognitive demands of 'on-side' games were greater than 'off-side' games. 'Off-side' games resulted in a greater total distance covered, greater distance covered in mild and moderate accelerations, and greater distance covered in low, moderate, and high-velocity efforts. There were also a greater number of short duration recovery periods between efforts in 'off-side' games. The results of this study demonstrate that 'off-side' games provide greater physiological and skill demands than 'on-side' games. 'Off-side' games may provide a practical alternative to 'on-side' games for the development of skill and fitness in elite rugby league players.

Hazardous Solvent Substitution Data System reference manual

International Nuclear Information System (INIS)

Branham-Haar, K.A.; Twitchell, K.E.

1993-07-01

Concern for the environment, in addition to Federal regulation, mandate the replacement of hazardous solvents with safer cleaning agents. Manufacturers are working to produce these replacement solvents. As these products are developed, potential users need to be informed of their availability. To promote the use of these new products instead of traditional solvents, the Idaho National Engineering Laboratory (INEL) has developed the Hazardous Solvent Substitution Data System (HSSDS). The HSSDS provides a comprehensive system of information on alternatives to hazardous solvents and related subjects, and it makes that information available to solvent users, industrial hygienists, and process engineers. The HSSDS uses TOPIC reg-sign, a text retrieval system produced by Verity, Inc., to allow a user to search for information on a particular subject. TOPIC reg-sign produces a listing of the retrieved documents and allows the use to examine the documents individually and to use the information contained in them. This reference manual does not replace the comprehensive TOPIC reg-sign user documentation (available from Verity, Inc.), or the HSSDS Tutorial (available from the INEL). The purpose of this reference manual is to provide enough instruction on TOPIC reg-sign so the user may begin accessing the data contained in the HSSDS

Gel-like properties of MCM-41 material and its transformation to MCM-50 in a caustic alkaline surround

International Nuclear Information System (INIS)

Saputra, Hens; Othman, Raihan; Sutjipto, A.G.E.; Muhida, R.; Ani, M.H.

2012-01-01

Highlights: ► MCM-41 material transforms gradually into MCM-50 lamellar gel upon controlled exposure to 6 M KOH. ► The formation of MCM-50 ordered gel structure occurs at KOH weight content of 40–70 wt. %. ► MCM gel phase shows pseudoplastic behavior and possesses homogeneous matrix texture. -- Abstract: MCM-41 material, prepared by sol–gel method, reveals gel-like properties in a caustic alkaline environment, i.e., 6 M potassium hydroxide (KOH) electrolyte. The gellation of MCM-41 starts at a KOH weight ratio of 40 wt.%. The structural change of the material is verified with X-Ray diffractograms and supported by observation using Scanning Electron Microscope (SEM). As the KOH weight ratio increases, the MCM-41 hexagonal arrays structure gradually transforms into MCM-50 lamellar structure before disappearing completely at 80 wt.% KOH. The MCM gel phase is further characterized by rotational viscometry and texture analysis. The gel phase shows shear thinning or pseudoplastic behavior and possesses homogeneous matrix structure.

Re-Refining of Waste Lubricating Oil by Solvent Extraction

Directory of Open Access Journals (Sweden)

Hassan Ali Durrani

2011-04-01

Full Text Available Re-refining of waste lubricating oil by solvent extraction is one of the potential techniques. The advantages of solvent extraction technique practically offers from environmental and economic points of view have received due attention. In this paper selection of composite solvent and technique to upgrade the used lubricant oil into base oil has been made. The composite solvent 2-propanol, 1-butanol and butanone have two alcohols that make a binary system reasonably effective. This work also attempts to study the performance of the composite solvent in the extraction process for recovering waste lubricating oil. The key parameters considered were vacuum pressure, temperature and the weight ratio of solvent to waste lubricating oil. The performance was investigated on the PSR (Percentage Sludge Removal and POL (Percent Oil Loss. The best results were obtained using composite solvent 25% 2-propanol, 37% 1-butanol and 38% butanone by a solvent to oil ratio of 6:1 at vacuum pressure 600mmHg and distillation temperature 250oC. The vacuum distilled oil pretreated with the composite solvents was matched to the standard base oil 500N and 150N, found in close agreement and could be used for similar purpose.

Nonhazardous solvent composition and method for cleaning metal surfaces

International Nuclear Information System (INIS)

Googin, J.M.; Simandl, R.F.; Thompson, L.M.

1993-01-01

A solvent composition for displacing greasy and oily contaminants as well as water and/or aqueous residue from metallic surfaces, especially surfaces of radioactive materials so that such surfaces can be wiped clean of the displaced contaminants, water and/or aqueous residue. The solvent composition consists essentially of a blend of nonpolar aliphatic hydrocarbon solvent having a minimum flash point of about 140 F and 2 to 25 volume percent of a polar solvent having a flash point sufficiently high so as to provide the solvent composition with a minimum flash point of at least 140 F. The solvent composition is nonhazardous so that when it is used to clean the surfaces of radioactive materials the waste in the form of paper or cloth wipes, lab coats and the like used in the cleaning operation is not considered to be mixed waste composed of a hazardous solvent and a radioactive material

Supercritical solvent extraction of oil sand bitumen

Science.gov (United States)

Imanbayev, Ye. I.; Ongarbayev, Ye. K.; Tileuberdi, Ye.; Mansurov, Z. A.; Golovko, A. K.; Rudyk, S.

2017-08-01

The supercritical solvent extraction of bitumen from oil sand studied with organic solvents. The experiments were performed in autoclave reactor at temperature above 255 °C and pressure 29 atm with stirring for 6 h. The reaction resulted in the formation of coke products with mineral part of oil sands. The remaining products separated into SARA fractions. The properties of the obtained products were studied. The supercritical solvent extraction significantly upgraded extracted natural bitumen.

Sustainable development of gree solvent separation process

OpenAIRE

Lisickov, Kiril; Fidancevska, Emilija; Grujic, Radoslav; Srebrenkoska, Vineta; Kuvendziev, Stefan

2011-01-01

Solvents defi ne a major part of the environmental performance of processes in the chemical industry and impact on cost, safety and health issues. The idea of green solvents expresses the goal to minimize the environmental impact resulting from the use of solvents in chemical production. In spite of conventional separation methods, precise process green technologies are based on the application of modern processes and process equipment as well as control and management...

Side Effects

Science.gov (United States)

Side effects are problems that occur when cancer treatment affects healthy tissues or organs. Learn about side effects caused by cancer treatment. Know what signs and symptoms to call your doctor about. Learn about treatments for side effects.

19F NMR spectroscopy in monitoring fluorinated-solvent regeneration

International Nuclear Information System (INIS)

Ogorodnikov, V.D.; Bordunov, V.V.

1987-01-01

Extensive use is made of solvents such as trichloroethylene, freon-133, and perchloroethylene because they are good solvents for inorganic, plant, and animal greases, while the solvents can be recovered and there is no fire hazard. In this paper, the authors examined methods to monitor spent solution regeneration rapidly and with high accuracy. The authors tested perfluorinated telomeric alcohols as solvents for cleaning engineering components which have melting points of 60-120 degrees celsius. The higher working temperatures and the increased energy consumption are disadvantages of these solvents, but these are compensated for by the scope for using them virtually in the solid, liquid, and vapor states. The authors' proposed technology is based on solvents with melting points over 40 degrees celsius which produce virtually no wastes. The telomeric alcohols are recovered after cooling to normal conditions by separation from the oil by filtration and centrifugation, and they can be used in the next purification cycle. When the solvents have been regenerated, the petroleum products such as industrial oils can be reused for their original purpose. However, quantitative data are required on the solvent contents in the oil and the oil contents in the solvent in order to determine the degree of regeneration and the modes to be used. The authors have also proposed a quantitative method of determining traces of these alcohols in oils and residual oils in the solvent by fluorine NMR. All measurements were made with a BS497 NMR spectrometer

Full scale solvent extraction remedial results

International Nuclear Information System (INIS)

Cash, A.B.

1992-01-01

Sevenson Extraction Technology, Inc. has completed the development of the Soil Restoration Unit (initially developed by Terra-Kleen Corporation), a mobile, totally enclosed solvent extraction treatment facility for the removal of organic contaminated media is greater by a closed loop, counter current process that recycles all solvents. The solvents used are selected for the individual site dependant upon the contaminants, such as PCB's, oil, etc. and the soil conditions. A mixture of up to fourteen non-toxic solvents can be used for complicated sites. The full scale unit has been used to treat one superfund site, the Traband Site in Tulsa, Oklahoma, and is currently treating another superfund site, the Pinette's Salvage Yard Site in Washburn, Maine. The full scale Soil Restoration Unit has also been used at a non-superfund site, as part of a TSCA Research and Development permit. The results from these sites will be discussed in brief herein, and in more detail in the full paper

Solvent annealing induced phase separation and dewetting in PMMA∕SAN blend film: film thickness and solvent dependence.

Science.gov (United States)

You, Jichun; Zhang, Shuangshuang; Huang, Gang; Shi, Tongfei; Li, Yongjin

2013-06-28

The competition between "dewetting" and "phase separation" behaviors in polymer blend films attracts significant attention in the last decade. The simultaneous phase separation and dewetting in PMMA∕SAN [poly(methyl methacrylate) and poly(styrene-ran-acrylonitrile)] blend ultrathin films upon solvent annealing have been observed for the first time in our previous work. In this work, film thickness and annealing solvent dependence of phase behaviors in this system has been investigated using atomic force microscopy and grazing incidence small-angle X-ray scattering (GISAXS). On one hand, both vertical phase separation and dewetting take place upon selective solvent vapor annealing, leading to the formation of droplet∕mimic-film structures with various sizes (depending on original film thickness). On the other hand, the whole blend film dewets the substrate and produces dispersed droplets on the silicon oxide upon common solvent annealing. GISAXS results demonstrate the phase separation in the big dewetted droplets resulted from the thicker film (39.8 nm). In contrast, no period structure is detected in small droplets from the thinner film (5.1 nm and 9.7 nm). This investigation indicates that dewetting and phase separation in PMMA∕SAN blend film upon solvent annealing depend crucially on the film thickness and the atmosphere during annealing.

Solvent extraction of thorium(IV) with dibutyldithiophosphoric acid in various organic solvents

International Nuclear Information System (INIS)

Curtui, M.; Haiduc, I.

1994-01-01

The extraction of thorium(IV) from perchlorate solutions with di-n-butyldithiophosphoric acid (HBudtp) in various organic solvents occurs through an ion exchange mechanism. The extracted species in the organic phase is an eight-coordinate complex Th(Budtp) 4 . The higher values of the distribution ratio obtained in HBudtp-benzene-water system than in HBudtp-n-butanol-water system are explained by higher solubility of the complex species in nonpolar solvents. The position of the extraction curves in the pH-range lower than 0.7 reduces the complexation of thorium(IV) with Budtp - in the aqueous phase and also the hydrolysis process. (author) 8 refs.; 4 figs.; 1 tab

Extractability of Lanthanoids(III) into Solvents Contributing to Environmental Protection

International Nuclear Information System (INIS)

Hasegawa, Y.; Hara, M.

1999-01-01

To perform effective mutual separation of lanthanoids(III) by solvent extraction with avoiding several problems caused by diffusion of organic solvents into air and into water , into commercial available mixed solvents, aliphatic and aromatic solvents consisting of carbon number of 9 to 12, which have high flash points, the extraction of lanthanoid(III) thiocyanates with trioctylphosphine oxide has been measured and the equilibrium constants have been determined across lanthanoid series. Then the extraction constants were compared with those of single solvents, hexane and benzene , widely being used as solvents for liquid-liquid extraction. The extraction constants obtained for the aliphatic mixed solvents are very similar to those for hexane across lanthanoid series. The variation of the constants for aromatic mixed solvents is also similar to that for benzene. The pattern of the variation of the distribution ratio under a constant condition across the series is similar to each other, either using the aliphatic solvents or using aromatic ones, except for in the middle of the series. Accordingly, the use of the high molecular weight mixed aromatic solvents would be recommendable as organic solvents in the mutual separation of lanthanoids from the point of view of safety for fire and health for the people handling the extraction

Studies on non dispersive solvent extraction for removal of dissolved di-butyl phosphate (DBP) from aqueous medium using hollow fiber membrane contactor

International Nuclear Information System (INIS)

Singh, Suman Kumar; Bindu, M.; Tripathi, S.C.; Gandhi, P.M.

2013-01-01

PUREX process is based on the principle of mass transfer by liquid liquid dispersion. Tri-n-butyl phosphate (TBP) is universal extractant for PUREX process which is employed for reprocessing the irradiated nuclear fuels for separation and recovery of fissile and fertile materials. The multi cycle solvent extraction processes encompass continuous extraction and stripping operations that are invariably carried out in pulsed columns. The continuous exposure of organic solvent (TBP) to high acidic and radioactive medium leads to decrease the solvent extraction efficiency as it degraded to different level producing di-butyl phosphate and mono-butyl phosphate in significant quantities. Efficiency of purex process decreases as di-butyl phosphate forms aqueous soluble complexes with uranium. Removal of such dissolved DBP from aqueous medium is of direct interest in reprocessing processes as this would enable to sustain the better efficiency of the process and also control the loss of fissile and fertile materials. The non-dispersive solvent extraction is a configuration of the conventional solvent-extraction process where a microporous membrane separates both the immiscible phases, one of which impregnates the membrane, thus bringing the liquid-liquid interface to one side of the membrane. This study is a preliminary evaluation of microporous hollow fiber membrane modules for the removal of dissolved DBP from acidic medium. The performance of the proposed system can be improved by optimizing controlling parameters of the process for quantitative transport of dissolved DBP from acidic medium in the purex process context

New Polymeric Membranes for Organic Solvent Nanofiltration

KAUST Repository

Aburabie, Jamaliah

2017-05-01

The focus of this dissertation was the development, synthesis and modification of polymers for the preparation of membranes for organic solvent nanofiltration. High chemical stability in a wide range of solvents was a key requirement. Membranes prepared from synthesized polymers as well as from commercial polymers were designed and chemically modified to reach OSN requirements. A solvent stable thin-film composite (TFC) membrane is reported, which is fabricated on crosslinked polythiosemicarbazide (PTSC) as substrate. The membranes exhibited high fluxes towards solvents like THF, DMF and DMSO ranging around 20 L/m2 h at 5 bar with a MWCO of around 1000 g/mol. Ultrafiltration PTSC membranes were prepared by non-solvent induced phase separation and crosslinked with GPTMS. The crosslinking reaction was responsible for the formation of an inorganic-type-network that tuned the membrane pore size. The crosslinked membranes acquired high solvent stability in DMSO, DMF and THF with a MWCO above 1300 g/mol. Reaction Induced Phase Separation (RIPS) was introduced as a new method for the preparation of skinned asymmetric membranes. These membranes have two distinctive layers with different morphologies both from the same polymer. The top dense layer is composed of chemically crosslinked polymer chains while the bottom layer is a porous structure formed by non-crosslinked polymer chains. Such membranes were tested for vitamin B12 in solvents after either crosslinking the support or dissolving the support and fixing the freestanding membrane on alumina. Pebax® 1657 was utilized for the preparation of composite membranes by simple coating. Porous PAN membranes were coated with Pebax® 1657 which was then crosslinked using TDI. Crosslinked Pebax® membranes show high stability towards ethanol, propanol and acetone. The membranes were also stable in DMF once crosslinked PAN supports were used. Sodium alginate polymer was investigated for the preparation of thin film composite

Electric Dipole Transition Moments and Solvent-Dependent Interactions of Fluorescent Boron-Nitrogen Substituted Indole Derivatives.

Science.gov (United States)

Saif, Mari; Widom, Julia R; Xu, Senmiao; Abbey, Eric R; Liu, Shih-Yuan; Marcus, Andrew H

2015-06-25

Fluorescent analogues of the indole side chain of tryptophan can be useful spectroscopic probes of protein-protein and protein-DNA interactions. Here we present linear dichroism and solvent-dependent spectroscopic studies of two fluorescent analogues of indole, in which the organic C═C unit is substituted with the isosteric inorganic B-N unit. We studied the so-called "external" BN indole, which has C2v symmetry, and the "fused" BN indole with Cs symmetry. We performed a combination of absorption and fluorescence spectroscopy, ultraviolet linear dichroism (UV-LD) in stretched poly(ethylene) (PE) films, and quantum chemical calculations on both BN indole compounds. Our measurements allowed us to characterize the degree of alignment for both molecules in stretched PE films. We thus determined the orientations and magnitudes of the two lowest energy electric dipole transition moments (EDTMs) for external BN indole, and the two lowest energy EDTMs for fused BN indole within the 30 000-45 000 cm(-1) spectral range. We compared our experimental results to those of quantum chemical calculations using standard density functional theory (DFT). Our theoretical predictions for the low-energy EDTMs are in good agreement with our experimental data. The absorption and fluorescence spectra of the external and the fused BN indoles are sensitive to solvent polarity. Our results indicate that the fused BN indole experiences much greater solvation interactions with polar solvents than does the external BN indole.

Solvent Handbook Database System user's manual

International Nuclear Information System (INIS)

1993-03-01

Industrial solvents and cleaners are used in maintenance facilities to remove wax, grease, oil, carbon, machining fluids, solder fluxes, mold release, and various other contaminants from parts, and to prepare the surface of various metals. However, because of growing environmental and worker-safety concerns, government regulations have already excluded the use of some chemicals and have restricted the use of halogenated hydrocarbons because they affect the ozone layer and may cause cancer. The Solvent Handbook Database System lets you view information on solvents and cleaners, including test results on cleaning performance, air emissions, recycling and recovery, corrosion, and non-metals compatibility. Company and product safety information is also available

Indium recovery by solvent extraction

International Nuclear Information System (INIS)

Fortes, Marilia Camargos Botelho

1999-04-01

Indium has been recovered as a byproduct from residues generated from the sulfuric acid leaching circuits in mineral plants for zinc recovery. Once its recovery comes from the slags of other metals recovery, it is necessary to separate it from the other elements which usually are present in high concentrations. Many works have been approaching this separation and indicate the solvent extraction process as the main technique used. In Brazilian case, indium recovery depends on the knowledge of this technique and its development. This paper describes the solvent extraction knowledge for the indium recovery from aqueous solutions generated in mineral plants. The results for determination of the best experimental conditions to obtain a high indium concentration solution and minimum iron poisoning by solvent extraction with di (2-ethylhexyl)-phosphoric acid (D2EHPA) solubilized in isoparafin and exxsol has been presented. (author)

Uranium refining by solvent extraction

International Nuclear Information System (INIS)

Kraikaew, J.

1996-01-01

The yellow cake refining was studied in both laboratory and semi-pilot scales. The process units mainly consist of dissolution and filtration, solvent extraction, and precipitation and filtration. Effect of flow ratio (organic flow rate/ aqueous flow rate) on working efficiencies of solvent extraction process was studied. Detailed studies were carried out on extraction, scrubbing and stripping processes. Purity of yellow cake product obtained is high as 90.32% U 3 O 8

Solvent extraction for spent nuclear fuel reprocessing plant

International Nuclear Information System (INIS)

Masui, Jinichi

1986-01-01

The purex process provides a solvent extraction method widely used for separating uranium and plutonium from nitric acid solution containing spent fuel. The Tokai Works has adopted the purex process with TPB-n dodecane as the extraction agent and a mixer settler as the solvent extraction device. The present article outlines the solvent extraction process and discuss the features of various extraction devices. The chemical principle of the process is described and a procedure for calculating the number of steps for countercurrent equilibrium extraction is proposed. Discussion is also made on extraction processes for separating and purifying uranium and plutonium from fission products and on procedures for managing these processes. A small-sized high-performance high-reliability device is required for carrying out solvent extraction in reprocessing plants. Currently, mixer settler, pulse column and centrifugal contactor are mainly used in these plants. Here, mixer settler is comparted with pulse column with respect to their past achievements, design, radiation damage to solvent, operation halt, controllability and maintenance. Processes for co-extraction, partition, purification and solvent recycling are described. (Nogami, K.)

Solvent jet desorption capillary photoionization-mass spectrometry.

Science.gov (United States)

Haapala, Markus; Teppo, Jaakko; Ollikainen, Elisa; Kiiski, Iiro; Vaikkinen, Anu; Kauppila, Tiina J; Kostiainen, Risto

2015-03-17

A new ambient mass spectrometry method, solvent jet desorption capillary photoionization (DCPI), is described. The method uses a solvent jet generated by a coaxial nebulizer operated at ambient conditions with nitrogen as nebulizer gas. The solvent jet is directed onto a sample surface, from which analytes are extracted into the solvent and ejected from the surface in secondary droplets formed in collisions between the jet and the sample surface. The secondary droplets are directed into the heated capillary photoionization (CPI) device, where the droplets are vaporized and the gaseous analytes are ionized by 10 eV photons generated by a vacuum ultraviolet (VUV) krypton discharge lamp. As the CPI device is directly connected to the extended capillary inlet of the MS, high ion transfer efficiency to the vacuum of MS is achieved. The solvent jet DCPI provides several advantages: high sensitivity for nonpolar and polar compounds with limit of detection down to low fmol levels, capability of analyzing small and large molecules, and good spatial resolution (250 μm). Two ionization mechanisms are involved in DCPI: atmospheric pressure photoionization, capable of ionizing polar and nonpolar compounds, and solvent assisted inlet ionization capable of ionizing larger molecules like peptides. The feasibility of DCPI was successfully tested in the analysis of polar and nonpolar compounds in sage leaves and chili pepper.

Ions, solutes and solvents, oh my!

Energy Technology Data Exchange (ETDEWEB)

Kemp, Daniel David [Iowa State Univ., Ames, IA (United States)

2009-08-01

Modern methods in ab initio quantum mechanics have become efficient and accurate enough to study many gas-phase systems. However, chemists often work in the solution phase. The presence of solvent molecules has been shown to affect reaction mechanisms1, lower reaction energy barriers2, participate in energy transfer with the solute3 and change the physical properties of the solute4. These effects would be overlooked in simple gas phase calculations. Careful study of specific solvents and solutes must be done in order to fully understand the chemistry of the solution phase. Water is a key solvent in chemical and biological applications. The properties of an individual water molecule (a monomer) and the behavior of thousands of molecules (bulk solution) are well known for many solvents. Much is also understood about aqueous microsolvation (small clusters containing ten water molecules or fewer) and the solvation characteristics when bulk water is chosen to solvate a solute. However, much less is known about how these properties behave as the cluster size transitions from the microsolvated cluster size to the bulk. This thesis will focus on species solvated with water clusters that are large enough to exhibit the properties of the bulk but small enough to consist of fewer than one hundred solvent molecules. New methods to study such systems will also be presented.

Green Michael addition of thiols to electron deficient alkenes using KF/alumina and recyclable solvent or solvent-free conditions

Energy Technology Data Exchange (ETDEWEB)

Lenardao, Eder J.; Trecha, Danusia O.; Ferreira, Patricia da C.; Jacob, Raquel G.; Perin, Gelson [Universidade Federal de Pelotas (UFPEL), Pelotas, RS (Brazil). Inst. de Quimica e Geociencias. Lab. de Sintese Organica Limpa (LASOL)]. E-mail: lenardao@ufpel.edu.br

2009-07-01

A general, clean and easy method for the conjugated addition of thiols to citral promoted by KF/Al{sub 2}O{sub 3} under solvent-free or using glycerin as recyclable solvent at room temperature is described. It was found that the solvent-free protocol is applicable to the direct reaction of thiophenol with the essential oil of lemon grass (Cymbopogon citratus) to afford directly 3,7-dimethyl-3-(phenylthio)oct-6-enal, a potential bactericide agent. The method was extended to other electron-poor alkenes with excellent results. For the solvent-free protocol, the use of microwave irradiation facilitated the procedure and accelerates the reaction. The catalytic system and glycerin can be reused up to three times without previous treatment with comparable activity. (author)

Side-chain tunability of furan-containing low-band-gap polymers provides control of structural order in efficient solar cells

KAUST Repository

Yiu, Alan T.; Beaujuge, Pierre; Lee, Olivia P.; Woo, Claire; Toney, Michael F.; Frechet, Jean

2012-01-01

The solution-processability of conjugated polymers in organic solvents has classically been achieved by modulating the size and branching of alkyl substituents appended to the backbone. However, these substituents impact structural order and charge transport properties in thin-film devices. As a result, a trade-off must be found between material solubility and insulating alkyl content. It was recently shown that the substitution of furan for thiophene in the backbone of the polymer PDPP2FT significantly improves polymer solubility, allowing for the use of shorter branched side chains while maintaining high device efficiency. In this report, we use PDPP2FT to demonstrate that linear alkyl side chains can be used to promote thin-film nanostructural order. In particular, linear side chains are shown to shorten π-π stacking distances between backbones and increase the correlation lengths of both π-π stacking and lamellar spacing, leading to a substantial increase in the efficiency of bulk heterojunction solar cells. © 2011 American Chemical Society.

Side-chain tunability of furan-containing low-band-gap polymers provides control of structural order in efficient solar cells

KAUST Repository

Yiu, Alan T.

2012-02-01

The solution-processability of conjugated polymers in organic solvents has classically been achieved by modulating the size and branching of alkyl substituents appended to the backbone. However, these substituents impact structural order and charge transport properties in thin-film devices. As a result, a trade-off must be found between material solubility and insulating alkyl content. It was recently shown that the substitution of furan for thiophene in the backbone of the polymer PDPP2FT significantly improves polymer solubility, allowing for the use of shorter branched side chains while maintaining high device efficiency. In this report, we use PDPP2FT to demonstrate that linear alkyl side chains can be used to promote thin-film nanostructural order. In particular, linear side chains are shown to shorten π-π stacking distances between backbones and increase the correlation lengths of both π-π stacking and lamellar spacing, leading to a substantial increase in the efficiency of bulk heterojunction solar cells. © 2011 American Chemical Society.

Activity coefficients of solutes in binary solvents

International Nuclear Information System (INIS)

Gokcen, N.A.

1982-01-01

The activity coefficients in dilute ternary systems are discussed in detail by using the Margules equations. Analyses of some relevant data at high temperatures show that the sparingly dissolved solutes in binary solvents follow complex behavior even when the binary solvents are very nearly ideal. It is shown that the activity data on the solute or the binary system cannot permit computation of the remaining activities except for the regular solutions. It is also shown that a fourth-order equation is usually adequate in expressing the activity coefficient of a solute in binary solvents at high temperatures. When the activity data for a binary solvent are difficult to obtain in a certain range of composition, the activity data for a sparingly dissolved solute can be used to supplement determination of the binary activities

Theoretical and experimental study of mixed solvent electrolytes

International Nuclear Information System (INIS)

Cummings, P.T.; O'Connell, J.P.

1990-01-01

In the original proposal to study mixed solvent electrolyte solutions, four major goals were formulated: fundamental modeling of mixed solvent electrolytes using numerically solved integral equation approximation theories; evaluation of intermolecular pair potential models by computer simulation of selected systems for comparison with experiment and the numerical integral equation studies; development of fundamentally based correlations for the thermodynamic properties of mixed solvent electrolyte solutions using analytically solvable statistical mechanical models; and extension of experimental database on mixed solvent electrolytes by performing vapor-liquid equilibrium measurements on selected systems. This paper discusses the progress on these goals

Enhanced performance of dicationic ionic liquid electrolytes by organic solvents

International Nuclear Information System (INIS)

Li, Song; Feng, Guang; Cummings Peter, T; Zhang, Pengfei; Fulvio Pasquale, F; Hillesheim Patrick, C; Dai, Sheng

2014-01-01

The use of dicationic ionic liquid (DIL) electrolytes in supercapacitors is impeded by the slow dynamics of DILs, whereas the addition of organic solvents into DIL electrolytes improves ion transport and then enhances the power density of supercapacitors. In this work, the influences of organic solvents on the conductivity of DILs and the electrical double layer (EDL) of DIL-based supercapacitors are investigated using classical molecular dynamics simulation. Two types of organic solvents, acetonitrile (ACN) and propylene carbonate (PC), were used to explore the effects of different organic solvents on the EDL structure and capacitance of DIL/organic solvent-based supercapacitors. Firstly, it was found that the conductivity of DIL electrolytes was greatly enhanced in the presence of the organic solvent ACN. Secondly, a stronger adsorption of PC on graphite results in different EDL structures formed by DIL/ACN and DIL/PC electrolytes. The expulsion of co-ions from EDLs was observed in DIL/organic solvent electrolytes rather than neat DILs and this feature is more evident in DIL/PC. Furthermore, the bell-shaped differential capacitance–electric potential curve was not essentially changed by the presence of organic solvents. Comparing DIL/organic solvent electrolytes with neat DILs, the capacitance is slightly increased by organic solvents, which is in agreement with experimental observation. (paper)

Desulfurization of Diesel Fuel by Oxidation and Solvent Extraction

Directory of Open Access Journals (Sweden)

Wadood Taher Mohammed

2015-02-01

Full Text Available This research presents a study in ultra-desulfurization of diesel fuel produced from conventional hydro desulfurization process, using oxidation and solvent extraction techniques. Dibenzothiophene (DBT was the organosulfur compound that had been detected in sulfur removal. The oxidation process used hydrogen peroxide as an oxidant and acetic acid as homogeneous catalyst . The solvent extraction process used acetonitrile (ACN and N-methyl – 2 - pyrrolidone (NMP as extractants . Also the effect of five parameters (stirring speed :150 , 250 , 350 , and 450 rpm, temperature (30 , 40 , 45 , and 50 oC, oxidant/simulated diesel fuel ratio (0.5 , 0.75 , 1 , and 1.5 , catalyst/oxidant ratio(0.125,0.25,0.5,and0.75 , and solvent/simulated diesel fuel ratio(0.5,0.6,0.75,and1 were examined as well as solvent type. The results exhibit that the highest removal of sulfur is 98.5% using NMP solvent while it is 95.8% for ACN solvent. The set of conditions that show the highest sulfur removal is: stirring speed of 350 rpm , temperature 50oC , oxidant/simulated diesel fuel ratio 1 , catalyst/oxidant ratio 0.5 , solvent/simulated diesel fuel ratio 1. These best conditions were applied upon real diesel fuel (produced from Al-Dora refinerywith 1000 ppm sulfur content . It was found that sulfur removal was 64.4% using ACN solvent and 75% using NMP solvent.

Measurement of oxygen transfer from air into organic solvents

DEFF Research Database (Denmark)

Ramesh, Hemalata; Mayr, Torsten; Hobisch, Mathias

2016-01-01

biological reactions require the supply of oxygen, most normally from air. However, reliable on-line measurements of oxygen concentration in organic solvents (and hence oxygen transfer rates from air to the solvent) has to date proven impossible due limitations in the current analytical methods. Results...... applications). Subsequently, we measured the oxygen transfer rates from air into these organic solvents. Conclusion The measurement of oxygen transfer rates from air into organic solvents using the dynamic method was established using the solvent resistant optical sensor. The feasibility of online oxygen...... For the first time, we demonstrate on-line oxygen measurements in non-aqueous media using a novel optical sensor. The sensor was used to measure oxygen concentration in various organic solvents including toluene, THF, isooctane, DMF, heptane and hexane (which have all been shown suitable for several biological...

Hazardous Solvent Substitution Data System tutorial

International Nuclear Information System (INIS)

Twitchell, K.E.; Skinner, N.L.

1993-07-01

This manual is the tutorial for the Hazardous Solvent Substitution Data System (HSSDS), an online, comprehensive system of information on alternatives to hazardous solvents and related subjects. The HSSDS data base contains product information, material safety data sheets, toxicity reports, usage reports, biodegradable data, product chemical element lists, and background information on solvents. HSSDS use TOPIC reg-sign to search for information based on a query defined by the user. TOPIC provides a full text retrieval of unstructured source documents. In this tutorial, a series of lessons is provided that guides the user through basic steps common to most queries performed with HSSDS. Instructions are provided for both window-based and character-based applications

Highly Efficient and Reproducible Nonfullerene Solar Cells from Hydrocarbon Solvents

KAUST Repository

Wadsworth, Andrew; Ashraf, Raja; Abdelsamie, Maged; Pont, Sebastian; Little, Mark; Moser, Maximilian; Hamid, Zeinab; Neophytou, Marios; Zhang, Weimin; Amassian, Aram; Durrant, James R.; Baran, Derya; McCulloch, Iain

2017-01-01

With chlorinated solvents unlikely to be permitted for use in solution-processed organic solar cells in industry, there must be a focus on developing nonchlorinated solvent systems. Here we report high-efficiency devices utilizing a low-bandgap donor polymer (PffBT4T-2DT) and a nonfullerene acceptor (EH-IDTBR) from hydrocarbon solvents and without using additives. When mesitylene was used as the solvent, rather than chlorobenzene, an improved power conversion efficiency (11.1%) was achieved without the need for pre- or post-treatments. Despite altering the processing conditions to environmentally friendly solvents and room-temperature coating, grazing incident X-ray measurements confirmed that active layers processed from hydrocarbon solvents retained the robust nanomorphology obtained with hot-processed chlorinated solvents. The main advantages of hydrocarbon solvent-processed devices, besides the improved efficiencies, were the reproducibility and storage lifetime of devices. Mesitylene devices showed better reproducibility and shelf life up to 4000 h with PCE dropping by only 8% of its initial value.

Highly Efficient and Reproducible Nonfullerene Solar Cells from Hydrocarbon Solvents

KAUST Repository

Wadsworth, Andrew

2017-06-01

With chlorinated solvents unlikely to be permitted for use in solution-processed organic solar cells in industry, there must be a focus on developing nonchlorinated solvent systems. Here we report high-efficiency devices utilizing a low-bandgap donor polymer (PffBT4T-2DT) and a nonfullerene acceptor (EH-IDTBR) from hydrocarbon solvents and without using additives. When mesitylene was used as the solvent, rather than chlorobenzene, an improved power conversion efficiency (11.1%) was achieved without the need for pre- or post-treatments. Despite altering the processing conditions to environmentally friendly solvents and room-temperature coating, grazing incident X-ray measurements confirmed that active layers processed from hydrocarbon solvents retained the robust nanomorphology obtained with hot-processed chlorinated solvents. The main advantages of hydrocarbon solvent-processed devices, besides the improved efficiencies, were the reproducibility and storage lifetime of devices. Mesitylene devices showed better reproducibility and shelf life up to 4000 h with PCE dropping by only 8% of its initial value.

Gas chromatographic analysis of extractive solvent in reprocessing plants

International Nuclear Information System (INIS)

Marlet, B.

1984-01-01

Operation of a reprocessing plant using the Purex process is recalled and analytical controls for optimum performance are specified. The aim of this thesis is the development of analytical methods using gas chromatography required to follow the evolution of the extraction solvent during spent fuel reprocessing. The solvent at different concentrations, is analysed along the reprocessing lines in organic or aqueous phases. Solvent degradation interferes with extraction and decomposition products are analysed. The solvent becomes less and less efficient, also it is distilled and quality is checked. Traces of solvent should also be checked in waste water. Analysis are made as simple as possible to facilitate handling of radioactive samples [fr

The influence of solvent processing on polyester bioabsorbable polymers.

Science.gov (United States)

Manson, Joanne; Dixon, Dorian

2012-01-01

Solvent-based methods are commonly employed for the production of polyester-based samples and coatings in both medical device production and research. The influence of solvent casting and subsequent drying time was studied using thermal analysis, spectroscopy and weight measurement for four grades of 50 : 50 poly(lactic-co-glycolic acid) (PLGA) produced by using chloroform, dichloromethane, and acetone. The results demonstrate that solvent choice and PLGA molecular weight are critical factors in terms of solvent removal rate and maintaining sample integrity, respectively. The protocols widely employed result in high levels of residual solvent and a new protocol is presented together with solutions to commonly encountered problems.

Acidic-basic properties of three alanine-based peptides containing acidic and basic side chains: comparison between theory and experiment.

Science.gov (United States)

Makowska, Joanna; Bagińska, Katarzyna; Liwo, Adam; Chmurzyński, Lech; Scheraga, Harold A

2008-01-01

The purpose of this work was to evaluate the effect of the nature of the ionizable end groups, and the solvent, on their acid-base properties in alanine-based peptides. Hence, the acid-base properties of three alanine-based peptides: Ac-KK-(A)(7)-KK-NH(2) (KAK), Ac-OO-(A)(7)-DD-NH(2) (OAD), Ac-KK-(A)(7)-EE-NH(2) (KAE), where A, D, E, K, and O denote alanine, aspartic acid, glutamic acid, lysine, and ornithine, respectively, were determined in water and in methanol by potentiometry. With the availability of these data, the ability of two theoretical methods to simulate pH-metric titration of those peptides was assessed: (i) the electrostatically driven Monte Carlo method with the ECEPP/3 force field and the Poisson-Boltzmann approach to compute solvation energy (EDMC/PB/pH), and (ii) the molecular dynamics method with the AMBER force field and the Generalized Born model (MD/GB/pH). For OAD and KAE, pK(a1) and pK(a2) correspond to the acidic side chains. For all three compounds in both solvents, the pK(a1) value is remarkably lower than the pK(a) of a compound modeling the respective isolated side chain, which can be explained by the influence of the electrostatic field from positively charged ornithine or lysine side chains. The experimental titration curves are reproduced well by the MD/GB/pH approach, the agreement being better if restraints derived from NMR measurements are incorporated in the conformational search. Poorer agreement is achieved by the EDMC/PB/pH method.

High temperature solvent extraction of oil shale and bituminous coal using binary solvent mixtures

Energy Technology Data Exchange (ETDEWEB)

Goetz, G.K.E. [Lehrstuhl fuer Geologie, Geochemie und Lagerstaetten des Erdoels und der Kohle, RWTH Aachen (Germany)

1997-12-31

A high volatile bituminous coal from the Saar Basin and an oil shale from the Messel deposit, both Germany, were extracted with binary solvent mixtures using the Advanced Solvent Extraction method (ASE). Extraction temperature and pressure were kept at 100 C, respectively 150 C, and 20,7 MPa. After the heating phase (5 min) static extractions were performed with mixtures (v:v, 1:3) of methanol with toluene, respectively trichloromethane, for further 5 min. Extract yields were the same or on a higher level compared to those from classical soxhlet extractions (3 days) using the same solvents at 60 C. Comparing the results from ASE with those from supercritical fluid extraction (SFE) the extract yields were similar. Increasing the temperature in ASE releases more soluble organic matter from geological samples, because compounds with higher molecular weight and especially more polar substances were solubilized. But also an enhanced extraction efficiency resulted for aliphatic and aromatic hydrocarbons which are used as biomarkers in Organic Geochemistry. Application of thermochemolysis with tetraethylammonium hydroxide (TEAH) using pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) on the extraction residues shows clearly that at higher extraction temperatures minor amounts of free fatty acids or their methyl esters (original or produced by ASE) were trapped inside the pore systems of the oil shale or the bituminous coal. ASE offers a rapid and very efficient extraction method for geological samples reducing analysis time and costs for solvents. (orig.)

The solvent effects on dimethyl phthalate investigated by FTIR characterization, solvent parameter correlation and DFT computation

Science.gov (United States)

Chen, Yi; Zhang, Hui; Zhou, Wenzhao; Deng, Chao; Liao, Jian

2018-06-01

This study set out with the aim of investigating the solvent effects on dimethyl phthalate (DMP) using FTIR characterization, solvent parameter correlation and DFT calculation. DMP exposed to 17 organic solvents manifested varying shift in the carbonyl stretching vibration frequency (νCdbnd O). Non-alkanols induced Band I and alkanols produced Band I and Band II. Through correlating the νCdbnd O with the empirical solvent scales including acceptor parameter (AN), Schleyer's linear free energy parameter (G), and linear free salvation energy relationships (LSER), Band I was mainly ascribed to non-specific effects from either non-alkanols or alkanol polymers ((alkanol)n). νCdbnd O of the latter indicated minor red shift and less variability compared to the former. An assumption was made and validated about the sequestering of hydroxyl group by the bulky hydrophobic chain in (alkanol)n, creating what we refer to as "screening effects". Ab initio calculation, on the other hand, provided insights for possible hydrogen binding between DMP and (ethanol)n or between ethanol monomers. The two components of Band I observed in inert solvents were assigned to the two Cdbnd O groups adopting differentiated conformations. This in turn prompted our consideration that hydrogen binding was highly selective in favor of lowly associated (alkanol)n and the particular Cdbnd O group having relatively less steric hindrance and stronger electron-donating capacity. Band II was therefore believed to derive from hydrogen-bond interactions mainly in manner of 1:1 and 1:2 DMP-(alkanol)n complexes.

21 CFR 173.280 - Solvent extraction process for citric acid.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Solvent extraction process for citric acid. 173.280... HUMAN CONSUMPTION Solvents, Lubricants, Release Agents and Related Substances § 173.280 Solvent extraction process for citric acid. A solvent extraction process for recovery of citric acid from...

Catalytic coal liquefaction with treated solvent and SRC recycle

Science.gov (United States)

Garg, Diwakar; Givens, Edwin N.; Schweighardt, Frank K.

1986-01-01

A process for the solvent refining of coal to distillable, pentane soluble products using a dephenolated and denitrogenated recycle solvent and a recycled, pentane-insoluble, solvent-refined coal material, which process provides enhanced oil-make in the conversion of coal.

Investigation of the Use of a Bio-Derived Solvent for Non-Solvent-Induced Phase Separation (NIPS Fabrication of Polysulfone Membranes

Directory of Open Access Journals (Sweden)

Xiaobo Dong

2018-05-01

Full Text Available Organic solvents, such as N-methyl-2-pyrrolidone (NMP and dimethylacetamide (DMAc, have been traditionally used to fabricate polymeric membranes. These solvents may have a negative impact on the environment and human health; therefore, using renewable solvents derived from biomass is of great interest to make membrane fabrication sustainable. Methyl-5-(dimethylamino-2-methyl-5-oxopentanoate (Rhodiasolv PolarClean is a bio-derived, biodegradable, nonflammable and nonvolatile solvent. Polysulfone is a commonly used polymer to fabricate membranes due to its thermal stability, strong mechanical strength and good chemical resistance. From cloud point curves, PolarClean showed potential to be a solvent for polysulfone. Membranes prepared with PolarClean were investigated in terms of their morphology, porosity, water permeability and protein rejection, and were compared to membranes prepared with traditional solvents. The pores of polysulfone/PolarClean membranes were sponge-like, and the membranes displayed higher water flux values (176.0 ± 8.8 LMH along with slightly higher solute rejection (99.0 ± 0.51%. On the other hand, PSf/DMAc membrane pores were finger-like with lower water flux (63.1 ± 12.4 LMH and slightly lower solute rejection (96 ± 2.00% when compared to PSf/PolarClean membranes.

Glutathione reductase: solvent equilibrium and kinetic isotope effects

International Nuclear Information System (INIS)

Wong, K.K.; Vanoni, M.A.; Blanchard, J.S.

1988-01-01

Glutathione reductase catalyzes the NADPH-dependent reduction of oxidized glutathione (GSSG). The kinetic mechanism is ping-pong, and we have investigated the rate-limiting nature of proton-transfer steps in the reactions catalyzed by the spinach, yeast, and human erythrocyte glutathione reductases using a combination of alternate substrate and solvent kinetic isotope effects. With NADPH or GSSG as the variable substrate, at a fixed, saturating concentration of the other substrate, solvent kinetic isotope effects were observed on V but not V/K. Plots of Vm vs mole fraction of D 2 O (proton inventories) were linear in both cases for the yeast, spinach, and human erythrocyte enzymes. When solvent kinetic isotope effect studies were performed with DTNB instead of GSSG as an alternate substrate, a solvent kinetic isotope effect of 1.0 was observed. Solvent kinetic isotope effect measurements were also performed on the asymmetric disulfides GSSNB and GSSNP by using human erythrocyte glutathione reductase. The Km values for GSSNB and GSSNP were 70 microM and 13 microM, respectively, and V values were 62 and 57% of the one calculated for GSSG, respectively. Both of these substrates yield solvent kinetic isotope effects greater than 1.0 on both V and V/K and linear proton inventories, indicating that a single proton-transfer step is still rate limiting. These data are discussed in relationship to the chemical mechanism of GSSG reduction and the identity of the proton-transfer step whose rate is sensitive to solvent isotopic composition. Finally, the solvent equilibrium isotope effect measured with yeast glutathione reductase is 4.98, which allows us to calculate a fractionation factor for the thiol moiety of GSH of 0.456

Equilibrium disorders in workers exposed to mixed solvents.

Science.gov (United States)

Giorgianni, Concetto; Tanzariello, Mariagiuseppina; De Pasquale, Domenico; Brecciaroli, Renato; Spatari, Giovanna

2018-02-06

Organic solvents cause diseases of the vestibular system. However, little is known regarding the correlation between vestibular damage and exposure to organic solvents below threshold limit values. The best measure by which to evaluate vestibular disorders is static and dynamic posturography. The aim of this study was to evaluate equilibrium disorders via static and dynamic posturography in workers without clear symptoms and exposed to low doses of mixed solvents. 200 subjects were selected. Using an Otometrics device (Madsen, Denmark), all subjects endured static and dynamic posturography testing with both eyes-open and eyes-closed conditions. Results were compared with a control group of unexposed individuals. Based on the obtained data, the following results can be drawn: (a) subjects exposed to mixtures of solvents show highly significant differences regarding all static and dynamic posturography parameters in comparison to the control group; (b) posturography testing has proven to be a valid means by which to detect subliminal equilibrium disorders in subjects exposed to solvents. We can confirm that refinery workers exposed to mixtures of solvents can present subliminal equilibrium disorders. Early diagnosis of the latter is made possible by static and dynamic posturography.

The impact of oil dispersant solvent on performance

International Nuclear Information System (INIS)

Fiocco, R.J.; Lessard, R.R.; Canevari, G.P.; Becker, K.W.; Daling, P.S.

1995-01-01

Modern oil spill dispersant formulations are concentrated blends of surface active agents (surfactants) in a solvent carrier system. The surfactants are effective for lowering the interfacial tension of the oil slick and promoting and stabilizing oil-in-water dispersions. The solvent system has 2 key functions: (1) reduce viscosity of the surfactant blend to allow efficient dispersant application, and (2) promote mixing and diffusion of the surfactant blend into the oil film. A more detailed description than previously given in the literature is proposed to explain the mechanism of chemical dispersion and illustrate how the surfactant is delivered by the solvent to the oil-water interface. Laboratory data are presented which demonstrate the variability in dispersing effectiveness due to different solvent composition, particularly for viscous and emulsified test oils with viscosities up to 20,500 mPa·s. Other advantages of improved solvent components can include reduced evaporative losses during spraying, lower marine toxicity and reduced protective equipment requirements. Through this improved understanding of the role of the solvent, dispersants which are more effective over a wider range of oil types are being developed

Modeling of Salt Solubilities in Mixed Solvents

DEFF Research Database (Denmark)

Chiavone-Filho, O.; Rasmussen, Peter

2000-01-01

A method to correlate and predict salt solubilities in mixed solvents using a UNIQUAC+Debye-Huckel model is developed. The UNIQUAC equation is applied in a form with temperature-dependent parameters. The Debye-Huckel model is extended to mixed solvents by properly evaluating the dielectric...... constants and the liquid densities of the solvent media. To normalize the activity coefficients, the symmetric convention is adopted. Thermochemical properties of the salt are used to estimate the solubility product. It is shown that the proposed procedure can describe with good accuracy a series of salt...

Solvent extraction in the nuclear fuel cycle

International Nuclear Information System (INIS)

Eccles, H.; Naylor, A.

1987-01-01

Solvent extraction techniques have been used in the uranium nuclear fuel cycle in three main areas; concentration of uranium from ore leach liquor, purification of ore concentrates and fuel reprocessing. Solvent extraction has been extended to the removal of transuranic elements from active waste liquor, the recovery of uranium from natural sources and the recovery of noble metals from active waste liquor. Schemes are presented for solvent extraction of uranium using the Amex or Dapex process; spent fuel reprocessing and the Purex process. Recent and future developments of the techniques are outlined. (UK)

Computing pKa Values in Different Solvents by Electrostatic Transformation.

Science.gov (United States)

Rossini, Emanuele; Netz, Roland R; Knapp, Ernst-Walter

2016-07-12

We introduce a method that requires only moderate computational effort to compute pKa values of small molecules in different solvents with an average accuracy of better than 0.7 pH units. With a known pKa value in one solvent, the electrostatic transform method computes the pKa value in any other solvent if the proton solvation energy is known in both considered solvents. To apply the electrostatic transform method to a molecule, the electrostatic solvation energies of the protonated and deprotonated molecular species are computed in the two considered solvents using a dielectric continuum to describe the solvent. This is demonstrated for 30 molecules belonging to 10 different molecular families by considering 77 measured pKa values in 4 different solvents: water, acetonitrile, dimethyl sulfoxide, and methanol. The electrostatic transform method can be applied to any other solvent if the proton solvation energy is known. It is exclusively based on physicochemical principles, not using any empirical fetch factors or explicit solvent molecules, to obtain agreement with measured pKa values and is therefore ready to be generalized to other solute molecules and solvents. From the computed pKa values, we obtained relative proton solvation energies, which agree very well with the proton solvation energies computed recently by ab initio methods, and used these energies in the present study.

N-terminal diproline and charge group effects on the stabilization of helical conformation in alanine-based short peptides: CD studies with water and methanol as solvent.

Science.gov (United States)

Goyal, Bhupesh; Srivastava, Kinshuk Raj; Durani, Susheel

2017-06-01

Protein folding problem remains a formidable challenge as main chain, side chain and solvent interactions remain entangled and have been difficult to resolve. Alanine-based short peptides are promising models to dissect protein folding initiation and propagation structurally as well as energetically. The effect of N-terminal diproline and charged side chains is assessed on the stabilization of helical conformation in alanine-based short peptides using circular dichroism (CD) with water and methanol as solvent. A1 (Ac-Pro-Pro-Ala-Lys-Ala-Lys-Ala-Lys-Ala-NH 2 ) is designed to assess the effect of N-terminal homochiral diproline and lysine side chains to induce helical conformation. A2 (Ac-Pro-Pro-Glu-Glu-Ala-Ala-Lys-Lys-Ala-NH 2 ) and A3 (Ac-dPro-Pro-Glu-Glu-Ala-Ala-Lys-Lys-Ala-NH 2 ) with N-terminal homochiral and heterochiral diproline, respectively, are designed to assess the effect of Glu...Lys (i, i + 4) salt bridge interactions on the stabilization of helical conformation. The CD spectra of A1, A2 and A3 in water manifest different amplitudes of the observed polyproline II (PPII) signals, which indicate different conformational distributions of the polypeptide structure. The strong effect of solvent substitution from water to methanol is observed for the peptides, and CD spectra in methanol evidence A2 and A3 as helical folds. Temperature-dependent CD spectra of A1 and A2 in water depict an isodichroic point reflecting coexistence of two conformations, PPII and β-strand conformation, which is consistent with the previous studies. The results illuminate the effect of N-terminal diproline and charged side chains in dictating the preferences for extended-β, semi-extended PPII and helical conformation in alanine-based short peptides. The results of the present study will enhance our understanding on stabilization of helical conformation in short peptides and hence aid in the design of novel peptides with helical structures. Copyright © 2017 European Peptide

40 CFR Table 5 to Subpart Vvvv of... - Default Organic HAP Contents of Solvents and Solvent Blends

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Contents of... Manufacturing Pt. 63, Subpt. VVVV, Table 5 Table 5 to Subpart VVVV of Part 63—Default Organic HAP Contents of Solvents and Solvent Blends As specified in § 63.5758(a)(6), when detailed organic HAP content data for...

Relation between the interfacial tension in an organic solvent-water system and the parameters of the solvating capacity of the solvent

International Nuclear Information System (INIS)

Nikitin, S.D.; Shmidt, V.S.

1987-01-01

It was shown that there is a linear relation between the empirical DE (diluent effect) and E/sub T/ parameters, which characterize the solvating capacity of the solvent, and the interfacial tension in an organic solvent-water two-phase system. Analysis of the sample correlation coefficients shows that the relation between the interfacial tension and the DE parameters of the solvents is closer to linear than the corresponding relation for the E/sub T/ parameters. During analysis of the data for 31 solvents it was established that the largest inverse correlation coefficient r = -0.98 is obtained with an equation of the DE = a + bσ/rho 1/3, type, were a and b are constants, and rho is the density of the solvent. The regression equation has the following form: DE = 7.586 - 0.147 σ/rho 1/3. Since the interfacial activity of hydrophobic surfactants decreases linearly with increase in the DE values, it follows from the obtained equation that decrease of the interfacial tension at the water-organic solvent interface must lead to a decrease in the interfacial activity of hydrophobic surfactants present in the system

DESIGNING GREENER SOLVENTS

Science.gov (United States)

Computer-aided design of chemicals and chemical mixtures provides a powerful tool to help engineers identify cleaner process designs and more-benign alternatives to toxic industrial solvents. Three software programs are discussed: (1) PARIS II (Program for Assisting the Replaceme...

Solvent-assisted polymer micro-molding

Institute of Scientific and Technical Information of China (English)

HAN LuLu; ZHOU Jing; GONG Xiao; GAO ChangYou

2009-01-01

The micro-molding technology has played an important role in fabrication of polymer micro-patterns and development of functional devices.In such a process,suitable solvent can swell or dissolve the polymer films to decrease their glass transition temperature (Tg) and viscosity and thereby improve flowing ability.Consequently,it is easy to obtain the 2D and 3D patterns with high fidelity by the solvent-assisted micro-molding.Compared with the high temperature molding,this technology overcomes some shortcomings such as shrinking after cooling,degradation at high temperature,difficulty in processing some functional materials having high Tg,etc.It can be applied to making patterns not only on polymer monolayers but also on polyelectrolyte multilayers.Moreover,the compressioninduced patterns on the multilayers are chemically homogenous but physically heterogeneous.In this review,the controlling factors on the pattern quality are also discussed,including materials of the mold,solvent,pressure,temperature and pattern density.

Solvent Extraction and Characterization of Neutral Lipids in Oocystis sp.

Directory of Open Access Journals (Sweden)

Renil eAnthony

2015-01-01

Full Text Available Microalgae are a favorable feedstock for bioproducts and biofuels due to their high oil content, fast growth rates and low resource demands. Solvent lipid extraction efficiency from microalgae is dependent on algal strain and the extraction solvent. Four non-polar extraction solvents were evaluated for the recovery of neutral cellular lipids from microalgae Oocystis sp. (UTEX LB2396. Methylene chloride, hexane, diethyl ether, and cyclohexane were selected as the extraction solvents. All solvent extracts contained hexadecanoic acid, linoleic acid and linolenic acid; accounting for 70% of total lipid content with a proportional wt% composition of the three fatty acids, except for the hexane extracts that showed only hexadecanoic acid and linoleic acid. While not statistically differentiated, methylene chloride proved to be the most effective solvent for Oocystis sp. among the four solvents tested with a total average neutral lipid recovery of 0.25% of dry weight followed by diethyl ether (0.18%, cyclohexane (0.14% and hexane (0.11%. This research presents a simple methodology to optimize the selection of lipid specific extraction solvents for the microalgal strain selected.

Partially Fluorinated Solvent as a co-solvent for the Non-aqueous Electrolyte of Li/air Battery

Science.gov (United States)

2010-11-11

ether ( MFE ) and tris(2,2,2-trifluoroethyl) phosphite (TTFP), respectively, as a co-solvent for the non-aqueous electrolyte of Li–air battery. Results...fluorinated solvents on the discharge performance of Li–air bat- tery. For this purpose, we here selectmethyl nonafluorobutyl ether ( MFE ) and tris...196, (2011) pgs. 2867-2870 14. ABSTRACT In this workwestudy methyl nonafluorobutyl ether ( MFE ) and tris(2,2,2-trifluoroethyl) phosphite (TTFP

Photophysical properties of coumarin-120: Unusual behavior in nonpolar solvents

International Nuclear Information System (INIS)

Pal, Haridas; Nad, Sanjukta; Kumbhakar, Manoj

2003-01-01

Photophysical properties of coumarin-120 (C120; 7-amino-4-methyl-1,2-benzopyrone) dye have been investigated in different solvents using steady-state and time-resolved fluorescence and picosecond laser flash photolysis (LFP) and nanosecond pulse radiolysis (PR) techniques. C120 shows unusual photophysical properties in nonpolar solvents compared to those in other solvents of moderate to higher polarities. Where the Stokes shifts (Δν-bar=ν-bar abs -ν-bar fl ), fluorescence quantum yields (Φ f ), and fluorescence lifetimes (τ f ) show more or less linear correlation with the solvent polarity function Δf={(ε-1)/(2ε+1)-(n 2 -1)/(2n 2 +1)}, all these parameters are unusually lower in nonpolar solvents. Unlike in other solvents, both Φ f and τ f in nonpolar solvents are also strongly temperature dependent. It is indicated that the excited singlet (S 1 ) state of C120 undergoes a fast activation-controlled nonradiative deexcitation in nonpolar solvents, which is absent in all other solvents. LFP and PR studies indicate that the intersystem crossing process is negligible for the present dye in all the solvents studied. Photophysical behavior of C120 in nonpolar solvent has been rationalized assuming that in these solvents the dye exists in a nonpolar structure, with its 7-NH 2 group in a pyramidal configuration. In this structure, since the 7-NH 2 group is bonded to the 1,2-benzopyrone moiety by a single bond, the former group can undergo a fast flip-flop motion, which in effect causes the fast nonradiative deexcitation of the dye excited state. In moderate to higher polarity solvents, it is indicated that the dye exists in an intramolecular charge-transfer structure, where the bond between 7-NH 2 group and the 1,2-benzopyrone moiety attains substantial double bond character. In this structure, the flip-flop motion of the 7-NH 2 group is highly restricted and thus there is no fast nonradiative deexcitation process for the excited dye

Thermodynamic properties of L-Theanine in different solvents

International Nuclear Information System (INIS)

Zhou, Fuli; Hou, Baohong; Tao, Xiaolong; Hu, Xiaoxue; Huang, Qiaoyin; Zhang, Zaixiang; Wang, Yongli; Hao, Hongxun

2017-01-01

Highlights: • The solubility data of L-Theanine in different solvents were measured by using an equilibrium method. • Several models were used to correlate the experimental solubility data. • The mixing thermodynamic properties were calculated. - Abstract: The solubility data of L-Theanine in pure water and three kinds of water + organic solvent mxitures were measured in temperature ranges from (278.15 to 13.15) K by using an equilibrium method. The results show that the solubility of L-Theanine increases with the increasing of temperature in all selected solvents. The modified Apelblat equation and the λ-h model were applied to correlate the solubility data in pure water, while the modified Apelblat equation, the λ-h model, the NRTL model and the Jouyban–Acree model were applied to correlate the solubility data in binary solvent mixtures. Furthermore, the mixing thermodynamic properties of L-Theanine in different solvents were also calculated based on the NRTL model and experimental solubility data.

27 CFR 20.113 - Proprietary solvents general-use formula.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Proprietary solvents... Formulas and Statements of Process General-Use Formulas § 20.113 Proprietary solvents general-use formula. (a) A proprietary solvent is any article made with any other ingredients combined with the...

Remediation of Contaminated Soils by Solvent Flushing

NARCIS (Netherlands)

Augustijn, Dionysius C.M.; Jessup, Ron E.; Rao, P. Suresh C.; Wood, A. Lynn

1994-01-01

Solvent flushing is a potential technique for remediating a waste disposal/spill site contaminated with organic chemicals. This technique involves the injection of a solvent mixture (e.g., water plus alcohols) that enhances contaminant solubility, reduces the retardation factor, and increases the

Performance of thermally-chargeable supercapacitors in different solvents.

Science.gov (United States)

Lim, Hyuck; Zhao, Cang; Qiao, Yu

2014-07-07

The influence of solvent on the temperature sensitivity of the electrode potential of thermally-chargeable supercapacitors (TCSs) is investigated. For large electrodes, the output voltage is positively correlated with the dielectric constant of solvent. When nanoporous carbon electrodes are used, different characteristics of system performance are observed, suggesting that possible size effects must be taken into consideration when the solvent molecules and solvated ions are confined in a nanoenvironment.

Solvent refining of low-temperature tar with liquid ammonia

Energy Technology Data Exchange (ETDEWEB)

Ishida, K

1953-01-01

The middle fractions of low-temperature tar were treated with mixed solutions of H/sub 2/O and liquid NH/sub 3/ at 0/sup 0/ and 20/sup 0/, and with liquid NH/sub 3/ at -10, 0, + 10, and 20/sup 0/, and phase equilibrium between tar acids, neutral oil, and solvents were studied. The distribution ratio ranged from less than 1 to greater than 1 when the solvent contained about 20 percent (by weight) H/sub 2/O. When the solvent contained less than 85 percent (by weight) NH/sub 3/, the yield of extract was small but the purity of phenols in the extracted oil was above 90 percent. Solvent containing about 85 percent NH/sub 3/ (by weight) is considered optimum for separating tar acids from oils. A novel definition is proposed for solvent selectivity as the difference between the concentration of the solute in the extract layer, on a solvent-free basis, and the concentration in the raffinate layer.

Trace elements retained in washed nuclear fuel reprocessing solvents

International Nuclear Information System (INIS)

Gray, L.W.; MacMurdo, K.W.

1979-09-01

Analysis of purified TBP extractant from solvent extraction processes at Savannah River Plant showed several stable elements and several long-lived radioisotopes. Stable elements Al, Na, Br, Ce, Hg, and Sm are found in trace quantities in the solvent. The only stable metallic element consistently found in the solvent was Al, with a concentration which varies from about 30 ppM to about 10 ppM. The halogens Br and Cl appear to be found in the solvent systems as organo halides. Radionuclides found were principally 106 Ru, 129 I, 3 H, 235 U, and 239 Pu. The 129 I concentration was about 1 ppM in the first solvent extraction cycle of each facility. In the other cycles, 129 I concentration varied from about 0.1 to 0.5 ppM. Both 129 I and 3 H appear to be in the organic solvent as a result of exchange with hydrogen

[Chemical hazards when working with solvent glues].

Science.gov (United States)

Domański, Wojciech; Makles, Zbigniew

2012-01-01

Solvent glues are used in a wide variety of industries, e.g., textile, footwear and rubber. The problem of workers' exposure to solvent vapors is rarely tackled within the area of occupational safety and health in small and medium-sized enterprises. In order to assess exposure to solvents, organic solvents emitted by glues were identified in the samples of workplace air. The concentration of acetone, benzene, cyclohexane, ethylbenzene, n-hexane, methylcyclohexane, butyl acetate and toluene were determined. The obtained results evidenced the presence of cyclohexane, ethylbenzene, ethylcyclohexane, heptane, n-hexane, o-xylene, methylcyclohexane, methylcyclopentane, butyl acetate and toluene in workplace air. The concentration of those compounds in workplace air was low, usually below 0.15 of MAC. At some workstations the presence of benzene was also observed. Occupational risk was assessed at workstations where gluing took place. It showed that the risk at those workstations was medium or low.

Amphiphilic polymer based on fluoroalkyl and PEG side chains for fouling release coating

Science.gov (United States)

Cong, W. W.; Wang, K.; Yu, X. Y.; Zhang, H. Q.; Lv, Z.; Gui, T. J.

2017-12-01

Under static conditions, fouling release coating could not express good release property to marine organisms. Amphiphilic polymer with mixture of fluorinated monomer and short side group of polyethylene glycol (PEG) was synthesized. And also we studied the ability of amphiphilic polymer to influence the surface properties and how it controlled the adhesion of marine organisms to coated surfaces. By incorporating fluorinated monomer and PEG side chain into the polymer, the effect of incorporating both polar and non-polar groups on fouling-release coating could be studied. The dry surface was characterized by three-dimensional digital microscopy and scanning electron microscopy (SEM), and the morphology of the amphiphilic fouling release coating showed just like flaky petal. The amphiphilic polymer in fouling release coating tended to reconstruct in water, and the ability was examined by static contact angle, which was smaller than the PDMS (polydimethylsiloxane) fouling release coating. Also surface energy was calculated by three solvents, and surface energy of amphiphilic fouling release coating was higher than that of the PDMS fouling release coating. To understand more about its fouling release property, seawater exposure method was adopted in gulf of Qingdao port. Fewer diatoms Navicula were found in biofilm after using amphiphilic fouling release coating. In general, coating containing both PEG and fluorinated side chain possessed certain fouling release property.

Deposition dynamics of multi-solvent bioinks

Science.gov (United States)

Kaneelil, Paul; Pack, Min; Cui, Chunxiao; Han, Li-Hsin; Sun, Ying

2017-11-01

Inkjet printing cellular scaffolds using bioinks is gaining popularity due to the advancement of printing technology as well as the growing demands of regenerative medicine. Numerous studies have been conducted on printing scaffolds of biomimetic structures that support the cell production of human tissues. However, the underlying physics of the deposition dynamics of bioinks remains elusive. Of particular interest is the unclear deposition dynamics of multi-solvent bioinks, which is often used to tune the micro-architecture formation. Here we systematically studied the effects of jetting frequency, solvent properties, substrate wettability, and temperature on the three-dimensional deposition patterns of bioinks made of Methacrylated Gelatin and Carboxylated Gelatin. The microflows inside the inkjet-printed picolitre drops were visualized using fluorescence tracer particles to decipher the complex processes of multi-solvent evaporation and solute self-assembly. The evolution of droplet shape was observed using interferometry. With the integrated techniques, the interplay of solvent evaporation, biopolymer deposition, and multi-drop interactions were directly observed for various ink and substrate properties, and printing conditions. Such knowledge enables the design and fabrication of a variety of tissue engineering scaffolds for potential use in regenerative medicine.

Qualitative and quantitative evaluation of solvent systems for countercurrent separation.

Science.gov (United States)

Friesen, J Brent; Ahmed, Sana; Pauli, Guido F

2015-01-16

Rational solvent system selection for countercurrent chromatography and centrifugal partition chromatography technology (collectively known as countercurrent separation) studies continues to be a scientific challenge as the fundamental questions of comparing polarity range and selectivity within a solvent system family and between putative orthogonal solvent systems remain unanswered. The current emphasis on metabolomic investigations and analysis of complex mixtures necessitates the use of successive orthogonal countercurrent separation (CS) steps as part of complex fractionation protocols. Addressing the broad range of metabolite polarities demands development of new CS solvent systems with appropriate composition, polarity (π), selectivity (σ), and suitability. In this study, a mixture of twenty commercially available natural products, called the GUESSmix, was utilized to evaluate both solvent system polarity and selectively characteristics. Comparisons of GUESSmix analyte partition coefficient (K) values give rise to a measure of solvent system polarity range called the GUESSmix polarity index (GUPI). Solvatochromic dye and electrical permittivity measurements were also evaluated in quantitatively assessing solvent system polarity. The relative selectivity of solvent systems were evaluated with the GUESSmix by calculating the pairwise resolution (αip), the number of analytes found in the sweet spot (Nsw), and the pairwise resolution of those sweet spot analytes (αsw). The combination of these parameters allowed for both intra- and inter-family comparison of solvent system selectivity. Finally, 2-dimensional reciprocal shifted symmetry plots (ReSS(2)) were created to visually compare both the polarities and selectivities of solvent system pairs. This study helps to pave the way to the development of new solvent systems that are amenable to successive orthogonal CS protocols employed in metabolomic studies. Copyright © 2014 Elsevier B.V. All rights reserved.

Collapse in two good solvents, swelling in two poor solvents: defying the laws of polymer solubility?

Science.gov (United States)

Mukherji, Debashish; Marques, Carlos M; Kremer, Kurt

2018-01-17

In this work we discuss two mirror but distinct phenomena of polymer paradoxical properties in mixed solvents: co-non-solvency and co-solvency. When a polymer collapses in a mixture of two miscible good solvents the phenomenon is known as co-non-solvency, while co-solvency is a phenomenon that is associated with the swelling of a polymer in poor solvent mixtures. A typical example of co-non-solvency is provided by poly(N-isopropylacrylamide) in aqueous alcohol, while poly(methyl methacrylate) in aqueous alcohol shows co-solvency. We discuss these two phenomena to compare their microscopic origins and show that both can be understood within generic universal concepts. A broad range of polymers is therefore expected to exhibit these phenomena where specific chemical details play a lesser role than the appropriate combination of interactions between the trio of molecular components.

Structuring of polymer solutions upon solvent evaporation

NARCIS (Netherlands)

Schaefer, C.; van der Schoot, P.|info:eu-repo/dai/nl/102140618; Michels, J. J.

2015-01-01

The morphology of solution-cast, phase-separated polymers becomes finer with increasing solvent evaporation rate. We address this observation theoretically for a model polymer where demixing is induced by steady solvent evaporation. In contrast to what is the case for a classical, thermal quench

Coordination conversion of cobalt(II) in binary aqueous-organic solvents

Energy Technology Data Exchange (ETDEWEB)

Khvostova, N.O.; Karapetyan, G.O.; Yanush, O.V.

1985-11-01

It has been shown that the thermochromic conversions of cobalt(II) in binary solvents are influenced by a number of factors: the nature of the solvent, the strength of the complexes of octahedral symmetry formed, the outer-sphere influence of the solvent on the complexes, the form of the anion, the solvation of the participants in the reaction, and the interaction of the components of the solvent with one another. A correlation between the strength and the spectral position of the absorption bands of the complexes of the activator has been established, and a spectroscopic criterion for selecting the solvents has been proposed. The expediency of using binary solvents to create effective thermochromic media with variable phototransmission has been substantiated.

ODC-Free Solvent Implementation Issues for Vulcanized Rubber and Bond Systems

Science.gov (United States)

Hodgson, James R.; McCool, Alex (Technical Monitor)

2001-01-01

Thiokol Propulsion has worked extensively to replace 1,1,1-trichloroethane (TCA) with ozone depleting chemicals (ODC)-free solvents for use in the manufacture of the Reusable Solid Rocket Motor (RSRM) for the Space Shuttle Program. As Thiokol has transitioned from sub-scale to full-scale testing and implementation of these new solvents, issues have been discovered which have required special attention. The original intent of Thiokol's solvent replacement strategy was to replace TCA with a single drop-in solvent for all equivalent applications. We have learned that a single candidate does not exist for replacing TCA. Solvent incompatibility with process materials has caused us to seek for niche solvents and/or processing changes that provide an ODC-free solution for special applications. This paper addresses some of the solvent incompatibilities, which have lead to processes changes and possible niche solvent usage. These incompatibilities were discovered during full-scale testing of ODC-free solvents and relate to vulcanized rubber and bond systems in the RSRM. Specifically, the following items are presented: (1) Cure effects of d-limonene based solvents on Silica Filled Ethylene Propylene Diene Monomer (SF-EPDM) rubber. During full-scale test operations, Thiokol discovered that d-limonene (terpene) based solvents inhibit the cure of EPDM rubber. Subsequent testing showed the same issue with Nitrile Butadiene Rubber (NBR). Also discussed are efforts to minimize uncured rubber exposure to solvents; and (2) Cured bond system sensitivity to ODC-free solvents. During full scale testing it was discovered that a natural rubber to steel vulcanized bond could degrade after prolonged exposure to ODC-free solvents. Follow on testing showed that low vapor pressure and residence time seemed to be most likely cause for failure.

Enzymes from solvent-tolerant microbes: useful biocatalysts for non-aqueous enzymology.

Science.gov (United States)

Gupta, Anshu; Khare, S K

2009-01-01

Solvent-tolerant microbes are a newly emerging class that possesses the unique ability to thrive in the presence of organic solvents. Their enzymes adapted to mediate cellular and metabolic processes in a solvent-rich environment and are logically stable in the presence of organic solvents. Enzyme catalysis in non-aqueous/low-water media is finding increasing applications for the synthesis of industrially important products, namely peptides, esters, and other trans-esterification products. Solvent stability, however, remains a prerequisite for employing enzymes in non-aqueous systems. Enzymes, in general, get inactivated or give very low rates of reaction in non-aqueous media. Thus, early efforts, and even some recent ones, have aimed at stabilization of enzymes in organic media by immobilization, surface modifications, mutagenesis, and protein engineering. Enzymes from solvent-tolerant microbes appear to be the choicest source for studying solvent-stable enzymes because of their unique ability to survive in the presence of a range of organic solvents. These bacteria circumvent the solvent's toxic effects by virtue of various adaptations, e.g. at the level of the cytoplasmic membrane, by degradation and transformation of solvents, and by active excretion of solvents. The recent screening of these exotic microbes has generated some naturally solvent-stable proteases, lipases, cholesterol oxidase, cholesterol esterase, cyclodextrin glucanotransferase, and other important enzymes. The unique properties of these novel biocatalysts have great potential for applications in non-aqueous enzymology for a range of industrial processes.

Solvent distillation studies for a purex reprocessing plant

International Nuclear Information System (INIS)

Ginisty, C.; Guillaume, B.

1990-01-01

A distillation system has been developed for regeneration of Purex solvent and will be implemented for the first time in a reprocessing plant. The results are described and analyzed, with emphasis on laboratory experiments which were made with a radioactive plant solvent. Particularly the distillation provides a good separation of solvent degradation products, which was verified by measurements of interfacial tension and plutonium or ruthenium retention. 16 refs., 3 figs., 5 tabs

Thermodynamic equilibrium of hydroxyacetic acid in pure and binary solvent systems