Browse Topic: Sodium

Items (64)
Find
Stable, Efficient, Anode-Free Sodium BatteryTBMG-3960508/01/2021
The challenges of energy storage — which require the capacity to bank an intermittent and seasonally variable supply of solar energy — have kept the technology from being economically competitive. Researchers have used low-cost materials to create rechargeable batteries that will make energy storage more affordable. These materials could also provide a safer and more environmentally friendly alternative to lithium-ion batteries that currently dominate the market but are slow to charge and have a knack for catching fire.
Wood-Based Technology Creates Electricity from HeatTBMG-3460806/01/2019
Researchers have transformed a piece of wood into a flexible membrane that generates energy from the same type of electric current (ions) on which the human body runs. This energy is generated using charged channel walls and other unique properties of the wood’s natural nanostructures. With this new wood-based technology, a small temperature differential can be used to efficiently generate ionic voltage.
Ingestible, Expanding Pill Monitors the Stomach for Up to a MonthTBMG-3462406/01/2019
An ingestible pill was developed that, upon reaching the stomach, quickly swells to the size of a soft, squishy ping-pong ball big enough to stay in the stomach for an extended period of time. The inflatable pill is embedded with a sensor that continuously tracks the stomach's temperature for up to 30 days. If the pill needs to be removed from the stomach, a patient can drink a solution of calcium that triggers the pill to quickly shrink to its original size and pass safely out of the body.
Are Internal Diesel Injector Deposits (IDID) Mainly Linked to Biofuel Chemical Composition or/and Engine Operation Condition?2019-01-006101/15/2019
The increased use of alternative fuels has been linked to performance deterioration of injectors and engines as a result of internal diesel injector deposits (IDID). The present paper investigates fuel composition impact on injector tendency to blockage. Three main areas were investigated : (1) deposits linked to paraffins and aromatics content; (2) deposits linked to biodiesel composition using fatty acid methyl esters (FAME) and hydrotreated vegetal oil (HVO); and (3) deposits linked to the presence of additives (Dodecenylsuccinic anhydride DDSA, Dodecenyl Succinimid DDSI and Sodium Naphthenate). A deposit formation method was developed for the injection bench in order to discriminate the impact of fuels on system performance in terms of fuel volume injected, injection duration and stability. Three operation conditions were tested to represent low, intermediate and high load. In addition, the influence of soaking time and injector heating temperature was evaluated. The nature of the
Alves Fortunato, Maira, Lenglet, Francis, Ben Amara, Arij, Starck, Laurie
Enhancement of Thermal Fatigue Strength by the Addition of Calcium to Hypoeutectic Aluminum-Silicon Alloys2018-32-002710/30/2018
Several elements affect the structure of eutectic silicon in hypoeutectic aluminum alloys [1, 2, 3, 4]. Among them, calcium has been investigated to a lesser extent compared to the typically used sodium and strontium. In order to enhance the thermal fatigue strength of a small engine, the morphology of eutectic silicon in hypoeutectic aluminum-silicon alloys is controlled by the addition of calcium. In addition, the castability and mechanical properties are investigated. Hence, samples containing different amounts of calcium are prepared at different cooling rates during solidification. The results revealed that, with the increase in the calcium amount and the cooling rate, eutectic silicon exhibits a fine morphology in cross-sectional images. Particularly, with the addition of at least 62 mass ppm of calcium in a specific range of cooling rates, refined eutectic silicon is obtained. In order to clarify additional effects of the added calcium, the amount of dissolved gas, fluidity, and
Watanabe, Kentaro, Motoyama, Kojiro, Watanabe, Tomokazu, Ishihara, Kazuhiro, Maeda, Fujio
Sodium Cooling Efficiency in Hollow Valves for Heavy Duty Engines2018-01-036804/03/2018
As a consequence of the ongoing evolution of engines, where performance is continuously improving and the use of alternative fuels is being adopted by many engine manufacturers, thermal working conditions of the exhaust valves are increasingly critical. In order to better resist the higher temperature levels of the exhaust gases, current development ranges from improvement of the cooling concept for the overall system, new materials for valve set components up to the upgrade of the exhaust manifold material. Change in the design of several valvetrain components due to the increased thermal loads is a logical consequence of this technical evolution process. Hollow exhaust valves filled with Sodium (Na) are a known technology that is widely used in passenger car engines to improve thermal behavior and to avoid the need to change to expensive materials (Ni-base alloys). Nevertheless, shaker-cooling effect of Na for engine speeds below 3.000 [rpm] has been questioned in the past and this
Zenklusen, Fernando, Coenca, Marcio, Puck, Alexander
The Effect of Near-Zero Aromatic Fuels on Internal Diesel Injector Deposit Test Methods2017-01-080703/28/2017
Internal diesel injector deposits (IDID) are now a well understood phenomenon and a standard test procedure has been developed and partially approved by the Coordinating European Council (CEC). The engine test procedure has been approved for simulation of sodium soap deposits by dosing the test fuel with a sodium salt and dodecenyl succinic acid (DDSA), whilst amide lacquer deposits simulation by dosing the test fuel with a low molecular weight (MWt) polyisobutylene succinimide (PIBSI) is still under development. The solubility of these contaminants in the base fuel should be reasonably constant to achieve consistent results. With the introduction of diesel from varying sources, this study focused on the effect of near-zero aromatics EN 15940 compliant gas-to-liquids GTL diesel, very similar to hydrotreated vegetable oil (HVO), on IDID severity across two different engine platforms, and the response of a modern deposit control additive. The test results showed that, with the same level
de Goede, Stefan, Barbour, Robert, Velaers, Adrian, Sword, Brian, Burton, Daniel, Mokheseng, Konrad
Engine Testing of Dissolved Sodium Borohydride for Diesel Combustion CO 2 Scrubbing2014-01-272910/13/2014
Improvements in the efficiency of internal combustion engines and the development of renewable liquid fuels have both been deployed to reduce exhaust emissions of CO2. An additional approach is to scrub CO2 from the combustion gases, and one potential means by which this might be achieved is the reaction of combustions gases with sodium borohydride to form sodium carbonate. This paper presents experimental studies carried out on a modern direct injection diesel engine supplied with a solution of dissolved sodium borohydride so as to investigate the effects of sodium borohydride on combustion and emissions. Sodium borohydride was dissolved in the ether diglyme at concentrations of 0.1 and 2 % (wt/wt), and tested alongside pure diglyme and a reference fossil diesel. The sodium borohydride solutions and pure diglyme were supplied to the fuel injector under an inert atmosphere and tested at a constant injection timing and constant engine indicated mean effective pressure (IMEP). The 0.1
Hellier, Paul, Ladommatos, Nicos, Headen, Tom, Bennington, Stephen
Chemical Composition of Ashless Polymeric Internal Diesel Injector Deposits2014-01-272810/13/2014
Internal Diesel Injector Deposits (IDIDs) have been known for some time. With the latest powertrains becoming ever more sophisticated and reliant on efficient fuel delivery, the necessity for a continued focus on limiting their formation remains. Initial studies probed both carbonaceous based/ashless polymeric and sodium salt based IDIDs. The reported occurrence of the latter variety of IDID has declined in recent years as a result of the removal of certain additives from the diesel distribution system. Conversely, ashless polymeric based deposits remain problematic and a regular occurrence in the field. The body of work presented in this contribution is an extension to that reported in SAE paper 2014-01-1401 which showed how a particular Fuel Borne Catalyst (FBC) additive has the ability to significantly reduce the formation of ashless polymeric deposits formed from the reaction of Poly-isobutylene Succinic Imides (PIBSI) with fatty acid and the ability for the same additive to also
Dallanegra, Romaeo, Caprotti, Rinaldo
Internal Injector Deposits From Sodium Sources2014-01-138804/01/2014
There have been reports of internal injector deposits causing problems in diesel engines in the field from 2008. Such problems manifest themselves as rough idling, power loss, high emissions, high-pressure fuel pump wear, injector sticking, internal component corrosion and engine failure. These reports coincided with the use of common rail diesel injection systems and of ultra-low sulphur fuels introduced because of emission regulation demands. The injection systems have design features that are more conducive or susceptible to deposit formation such as severe high temperature and pressure operating conditions, the tolerances of critical parts, and lower force internal component actuation. The changes to fuels have also affected the fuels ability to solubilise these deposits. The deposits formed manifest themselves in complex form in the field, often being mixtures of inorganic and organic compounds. One sub-group of this complex picture that is of current major interest is “sodium
Reid, Jacqueline, Cook, Stephen, Barker, Jim
Validation of Fuel Borne Catalyst Technology in Advanced Diesel Applications2014-01-140104/01/2014
The use of Diesel Particulate Filters (DPFs) as a means to meet ever more stringent worldwide Particulate Matter/ Particle Number (PM/ PN) emissions regulations is increasing. Fuel Borne Catalyst (FBC) technology has now been successfully used as an effective system for DPF regeneration in factory and service fill as well as retrofit applications for several years. The use of such a technology dictates that it be stable in long term service and that it remains compatible with new and emerging diesel fuel grades. In order to ensure this, neat additive stability data have been generated in a very severe and highly transient temperature cycle and a large selection of current (Winter 2012) market fuels have been evaluated for stability with this FBC technology. Results indicate that FBC technology remains suitable. The incidence of Internal Diesel Injector Deposits (IDIDs) is increasing, particularly for advanced FIE systems. These deposits generate a variety of field issues that can, in
Dallanegra, Romaeo, Caprotti, Rinaldo
Sodium Contamination of Diesel Fuel, its Interaction with Fuel Additives and the Resultant Effects on Filter Plugging and Injector Fouling2013-01-268710/14/2013
Diesel fuel distilled from crude oil should contain no greater than trace amounts of sodium. However, fuel specifications do not include sodium; there is a limit of five parts per million for the amount of sodium plus potassium in fatty acid methyl esters (FAME) used as biodiesel. Sodium compounds are often used as the catalyst for the esterification process for producing FAME and sodium hydroxide is now commonly used in the refining process to produce ultra-low sulphur diesel (ULSD) fuel from crude oil. Good housekeeping should ensure that sodium is not present in the finished fuel. A finished fuel should not only be free of sodium but should also contain a diesel fuel additive package to ensures the fuel meets the quality standards introduced to provide reliable operation, along with the longevity of the fuel supply infrastructure and the diesel engines that ultimately burn this fuel. There has recently been an upsurge in reported field problems due to fouling of the fuel injection
Barker, Jim, Cook, Stephen, Richards, Paul
De-Icer Quantification and Phase Transition Detection by Raman Spectroscopy2013-01-210109/17/2013
Winter maintenance is based on the intervention of operating services, as well as the use of deicers. Each year, in France, thousands of tons of deicers are spread through runways and taxiways. On the airport sector, the main deicers are sodium or potassium acetates and formates. All these deicers aim to prevent ice formation (preventive strategy) and/or improve the ice melting of snow residual film (curative strategy) at temperatures below 0°C. The operating principle of these compounds is based on the lowering of the solution's freezing point once dissolved in water. The phase diagram's knowledge is predominant to determine the deicer's amount to be applied on the surface. It provides a way to optimize their amounts applied with respect to weather conditions, present or forecasted. The Center for Technical Studies of Equipment in East of France (CETE de l'Est) developed and implemented a method based on Raman spectroscopy to characterize aqueous solutions of airport de-icers. This
Durickovic, Ivana, Marchetti, Mario, Poissonnier, Stephanie, Casteran, Guillaume, Mansour, Rachel, Schweigert, Nathalie, Mars, Benoit
Specialty Metals Make Sophisticated Medical Devices PossibleTBMG-1720609/01/2013
Around the world, people are living longer, more active lives thanks to continuing advancements in medical technology. This evolution in technology stems from the development of metals and alloys that are finding new uses in internal and external medical applications. From improvements in diagnostic guide wires to new alloys for permanent implants in the body, metals continue to find new uses.
Lithium Batteries for Medical ApplicationsTBMG-1511011/01/2012
The element lithium possesses fundamental properties that make it ideal for use as the anode in both primary and rechargeable batteries. Vendors have paired the popular lithium anode with a variety of cathode and electrolyte materials, resulting in the wide choice of different chemistries available today. This article discusses the types of primary lithium batteries commonly used for medical applications and introduces a new type based on recent innovations in materials and manufacturing processes. Information about the basic properties, advantages, and disadvantages are provided for each battery type.
Study Of Chemical Analysis Of Oil Applying Data Mining Techniques2012-36-041210/02/2012
The study of the wear track oil analysis is a technique commonly used in industrial, preventive and predictive maintenance of mechanical systems that suffer during the process of deterioration in service. This technique allows to study the behavior of the elements suspended in the lubricating oil. The paper proposes developing maps representing the wear of diesel analyzing the chemical analysis of the lubricating oil by the correlation of the chemical elements with the alloys of the mechanical components of the system. The methodology of this study was based on using data mining techniques for obtaining the data clustering of chemical analyzes, using the MATLAB 6.5 to obtain the maps. The software allows the display of trend curves, graphic correlation between the elements that have convergent or divergent behavior, interpolation and curve fitting as well as the clustering of elements in a map of wear on the engines examined.
Marinho, E. S. J., Silva Neto, R. D. A., Medeiros, J. S., Assis, L., Pantaleon, E.
Internal Diesel Injector Deposits: Sodium Carboxylates of C12 Succinic Acids and C16 and C18 Fatty Acids2012-01-168909/10/2012
Over the last few years, problems caused by internal injector deposits have appeared sporadically in Spain. These deposits can lead to engine vibrations, unstable idling or poor starting. This paper presents and discusses the results of a study on the internal deposits of common rail injectors from light and heavy-duty vehicles from the field in Spain since 2005. Using analytical techniques like SEM-EDS, FTIR and GC-MS, the internal deposits were analyzed and found to be composed mainly of carboxylic salts from C12 succinic acids and C16 and C18 fatty acids. Several fuel additives were analyzed using the procedure developed in this work and evidence was obtained to the effect that the chemical composition of corrosion inhibitor additive, which have been used in Spanish pipelines during the last few years, relates to the formation of the internal deposits found in the common rail injectors studied, when sodium ions are present in the fuel. A common rail diesel engine test was developed
Cardenas Almena, Maria Dolores, Lucio Esperilla, Octavio, Martin Manzanero, Francisco, Murillo Duarte, Yolanda, Quintero Toscano, Luis Carlos, Wolff, Guillermo
Production of Biobased Lubricant Basestocks with Improved Performance2012-01-162009/10/2012
The ability of a catalyst to enhance the performance of synthesized biobased lubricant basestock was investigated in this study. Pomace olive oil, cottonseed oil, used frying oil and methyl oleate were utilized as starting materials for the production of the biobased lubricants and a two stages transesterification methodology was followed. Initially the oils were converted to their corresponding fatty acid methyl esters via methanolysis. The resulting methylesters were subsequently transesterified with TMP producing the desired oleochemical ester. These syntheses were carried out in the presence of either sodium methoxide or Ca/TEA alkoxide as catalysts. Following the purification phase, the synthesized esters were evaluated as potential biolubricants regarding their physicochemical properties such as viscosity index, pour point and acid value. Oxidation stability differentiations were determined in a Rancimat accelerated oxidation unit as well as in a Rapid Small Scale Oxidation Test
Dodos, George S., Anastopoulos, George, Zannikos, Fanourios
Saliva Preservative for Diagnostic PurposesTBMG-1423708/01/2012
Saliva is an important body fluid for diagnostic purposes. Glycoproteins, glucose, steroids, DNA, and other molecules of diagnostic value are found in saliva. It is easier to collect as compared to blood or urine. Un for tunately, saliva also contains large numbers of bacteria that can release enzymes, which can degrade proteins and nucleic acids. These degradative enzymes destroy or reduce saliva’s diagnostic value. This innovation describes the formulation of a chemical preservative that prevents microbial growth and inactivates the degradative enzymes. This extends the time that saliva can be stored or transported without losing its diagnostic value. Multiple samples of saliva can be collected if needed without causing discomfort to the subject and it does not require any special facilities to handle after it is collected.
Imidazolium-Based Polymeric Materials as Alkaline Anion-Exchange Fuel Cell MembranesTBMG-1423208/01/2012
Polymer electrolyte membranes that conduct hydroxide ions have potential use in fuel cells. A variety of polystyrenebased quaternary ammonium hydroxides have been reported as anion exchange fuel cell membranes. However, the hydrolytic stability and conductivity of the commercially available membranes are not adequate to meet the requirements of fuel cell applications. When compared with commercially available membranes, polystyrene-imidazolium alkaline membrane electrolytes are more stable and more highly conducting. At the time of this reporting, this has been the first such usage for imidazolium-based polymeric materials for fuel cells.
Convention Center Expands LED Lighting RetrofitTBMG-1442107/01/2012
As part of its preparations to host the London 2012 Olympic Games, the ExCeL London International Exhibition & Convention Centre expanded its efforts to convert the facility to greener, more energy-efficient LED lighting, replacing 35 existing 400W high-pressure sodium (HPS) fixtures with Dialight’s new 150W 14,000-lumen High Bay LEDs to better illuminate the north side exterior of the massive structure in the loading dock and traffic marshaling areas.
Possible Mechanism for Poor Diesel Fuel Lubricity in the Field2012-01-086704/16/2012
Traditionally, diesel fuel injection equipment (FIE) has frequently relied on the diesel fuel to lubricate the moving parts. When ultra low sulphur diesel fuel was first introduced into some European markets in the early 1980's it rapidly became apparent that the process of removing the sulphur also removed other components that had bestowed the lubricating properties of the diesel fuel. Diesel fuel pump failures became prevalent. The fuel additive industry responded quickly and diesel fuel lubricity additives were introduced to the market. The fuel, additive and FIE industries expended much time and effort to develop test methods and standards to try and ensure this problem was not repeated. Despite this, there have recently been reports of fuel reaching the end user with lubricating performance below the accepted standards. Recent publications have also suggested that it is not uncommon for sodium hydroxide used in the fuel refining industry to be present in fuel entering the supply
Cook, Stephen, Barker, Jim, Reid, Jacqueline, Richards, Paul
GE Electric Drivetrain Technologies for Lightweight Battery Dominant Hybrid Fuel Cell Bus2012-01-102904/16/2012
Aside from the fuel cell prime mover, the drivetrain elements of a fuel cell hybrid transit bus are those of a heavy-duty series hybrid vehicle. The U.S. National Fuel Cell Bus Program is advancing all aspects of fuel cell transit bus technology, including fuel cells and other electric drivetrain technologies. Key electric drivetrain technologies developed by General Electric (GE) in the Lightweight Battery-dominant Hybrid Fuel Cell Bus project, their integration to the vehicle design, together with the vehicle build and demonstration plans are described. The GE technologies are sodium metal halide energy batteries, the dual battery energy storage system, energy management controls and dc-dc converter power electronics. Further electric drive vehicle technology developments focused on the fuel cell transit bus application are proposed.
Salasoo, Lembit, Richter, Tim, King, Robert D, Li, Zhihao
Separation of Single-Walled Carbon Nanotubes with DEP-FFFTBMG-1073908/01/2011
A process using a modified dielectrophoresis device separates single-walled carbon nanotubes (SWNTs) according to their polarizability in electric fields. This depends on the size and dielectric constant of individual nanotubes and easily separates metallic from semiconducting nanotubes. Separation by length has also been demonstrated. Partial separation (enrichment) according to bandgap (which is linked to polarizability) has also been shown and can be improved to full separation of individual types of semiconducting SWNTs with better control over operational parameters and the length of SWNT starting material. This process and device can be scaled affordably to generate useful amounts of semiconducting SWNTs for electronic device development and production.
Separation of Single-Walled Carbon Nanotubes with DEP-FFFTBMG-TB-01073908/01/2011
Simultaneous type and diameter separation of SWNTs is achieved by using flow injection dielectrophoresis. A process using a modified dielectrophoresis device separates single-walled carbon nanotubes (SWNTs) according to their polarizability in electric fields. This depends on the size and dielectric constant of individual nanotubes and easily separates metallic from semiconducting nanotubes. Separation by length has also been demonstrated. Partial separation (enrichment) according to bandgap (which is linked to polarizability) has also been shown and can be improved to full separation of individual types of semiconducting SWNTs with better control over operational parameters and the length of SWNT starting material. This process and device can be scaled affordably to gener- ate useful amounts of semiconducting SWNTs for electronic device development and production.
Technology Eliminates the Need for Pre-Wetting Cartridge FiltersTBMG-1045107/01/2011
There has been a long-term need in the filtration industry — particularly for a variety of life science applications — to eliminate the need for pre-wetting cartridge filters with alcohol before sending them to customers. It is not only an expensive, time-consuming process, but it also increases the risk of bacterial contamination.
Shopping Plaza Parking Lot Lighting-RetrofitTBMG-1434602/01/2011
A Manchester, NH T.J.Maxx shopping plaza parking lot has been retrofitted with BetaLED luminaires. CBT Development of Greenland, NH was incurring high costs for parking lot maintenance from frequent lamp replacement in high pressure sodium (HPS) and metal halide (MH) fixtures. While poor power quality was causing the premature lamp failure, the developer was ready to replace the 25-year old luminaires with new, efficient technology. The parking lot covers approximately 151,000 square feet and has 385 parking spaces.
Compact, Lightweight Electromagnetic Pump for Liquid MetalTBMG-830508/01/2010
A proposed direct-current electromagnetic pump for circulating a molten alkali metal alloy would be smaller and lighter and would demand less input power, relative to currently available pumps of this type. (Molten alkali metals are used as heat-transfer fluids in high-temperature stages of some nuclear reactors.) The principle of operation of this or any such pump involves exploitation of the electrical conductivity of the molten metal: An electric current is made to pass through the liquid metal along an axis perpendicular to the longitudinal axis of the flow channel, and a magnetic field perpendicular to both the longitudinal axis and the electric current is superimposed on the flowchannel region containing the electric current. The interaction between the electric current and the magnetic field produces the pumping force along the longitudinal axis. The advantages of the proposed pump over other such pumps would accrue from design features that address overlapping thermal and
Custom Assembly Helps Create Medical-Grade Saline in SpaceTBMG-804206/01/2010
BioConnect® bag and tubing assemblies Cole-Parmer Instrument Vernon Hills, IL 800-323-4340 www.coleparmer.com
System for Removing Pollutants From Incinerator ExhaustTBMG-342712/01/2008
A system for removing pollutants — primarily sulfur dioxide and mixed oxides of nitrogen (NOx) — from incinerator exhaust has been demonstrated. The system is also designed secondarily to remove particles, hydrocarbons, and CO. The system is intended for use in an enclosed environment, for which a prior NOx-and-SO2-removal system designed for industrial settings would not be suitable. The incinerator exhaust first encounters a cyclone separator, a primary heat exchanger, and a fabric filter that, together, remove particles and reduce the temperature to 500 °C. The exhaust then passes through a porous bed, maintained at ≈ 450 °C, that contains Na2CO3, which absorbs SO2.
System for Removing Pollutants From Incinerator ExhaustTBMG-541912/01/2008
A system for removing pollutants — primarily sulfur dioxide and mixed oxides of nitrogen (NOx) — from incinerator exhaust has been demonstrated. The system is also designed secondarily to remove particles, hydrocarbons, and CO. The system is intended for use in an enclosed environment, for which a prior NOx-and-SO2-removal system designed for industrial settings would not be suitable. The incinerator exhaust first encounters a cyclone separator, a primary heat exchanger, and a fabric filter that, together, remove particles and reduce the temperature to 500 °C. The exhaust then passes through a porous bed, maintained at ≈ 450 °C, that contains Na2CO3, which absorbs SO2.
Shielding Effectiveness of Sodium Alanate and Ammonia Borane for Galactic Cosmic Ray and Solar Energetic Particle Event Environments2008-01-216306/29/2008
Estimates of the effectiveness of the high-hydrogen containing materials, sodium alanate and ammonia borane, are made by calculating dose and dose equivalent for the 1977 solar minimum and 1970 solar maximum galactic cosmic ray spectra and for the large solar particle event spectra from the space era event of August 1972 and comparing their shielding effectiveness with that of polyethylene.
Townsend, Lawrence W., Yancey, David, Thomas, Peter, Atwell, William
Colorimetric-Solid Phase Extraction (C-SPE): In-Flight Methodologies for the Facile Determination of Trace Level Indicators of Water Quality2008-01-220106/29/2008
At present, spacecraft water quality is assessed when samples collected on the International Space Station (ISS) are returned to Earth. Several months, however, may pass between sample collection and analysis, potentially compromising sample integrity by risking degradation. For example, iodine and silver, which are the respective biocides used in the U.S. and Russian spacecraft potable water systems, must be held at levels that prevent bacterial growth, while avoiding adverse effects on crew health. A comparable need exists for the detection of many heavy metals, toxic organic compounds, and microorganisms. Lead, cadmium, and nickel have been found, for instance, in the ISS potable water system at amounts that surpass existent requirements. There have been similar occurrences with hazardous organic compounds like formaldehyde and ethylene glycol. Microorganism counts above acceptable limits have also been reported in a few instances. The delays in analyzing potable water suspend
Porter, Marc D., Siperko, Lorraine M., Nordling, John, Hazen-Bosveld, April A., Shih, Chien-Ju, Lipert, Robert J., Fritz, James S.
Fabricating Nanodots Using Lift-Off of a Nanopore TemplateTBMG-286106/01/2008
A process for fabricating a planar array of dots having characteristic dimensions of the order of several nanometers to several hundred nanometers involves the formation and use of a thin alumina nanopore template on a semiconductor substrate. The dot material is deposited in the nanopores, then the template is lifted off the substrate after the dots have been formed. This process is expected to be a basis for development of other, similar nanofabrication processes for relatively inexpensive mass production of nanometer- scale optical, optoelectronic, electronic, and magnetic devices.
Mixed Conducting Electrodes for Better AMTEC CellsTBMG-TB-00114702/07/2007
These electrodes conduct both electrons and sodium cations. Electrode materials that exhibit mixed conductivity (that is, both electronic and ionic conductivity) have been investigated in a continuing effort to improve the performance of the alkali metal thermal-to-electric converter (AMTEC). These electrode materials are intended primarily for use on the cathode side of the sodium-ion-conducting solid electrolyte of a sodium-based AMTEC cell. They may also prove useful in sodium-sulfur batteries, which are under study for use in electric vehicles.
Bonding-Compatible Corrosion Inhibitor for Rinsing MetalsTBMG-165112/01/2005
A corrosion-inhibiting mixture of compounds has been developed for addition to the water used to rinse metal parts that have been cleaned with aqueous solutions in preparation for adhesive bonding of the metals to rubber and rubberlike materials. Prior to the development of this corrosion inhibitor, the parts (made, variously, of D6AC steel and 7075-T73 aluminum) were rinsed by deionized water, which caused corrosion in some places on the steel parts — especially in such occluded places as sealing surfaces and threaded blind holes.
Trace Level Determination of Lead(II) in Water by Colorimetric-Solid Phase Extraction2005-01-288907/11/2005
Preliminary results on the development of quick, simple analytical method for the low level of lead(II) in water samples are described. The method concentrates lead(II) on a small solid-phase extraction disk, which is then quantified directly on the disk by diffuse reflectance spectroscopy (DRS). This method, termed colorimetric solid-phase extraction (C-SPE), requires only 1–2 min for complete workup and is suitable for use in a wide range of applications, including the microgravity environment on the International Space Station. The procedure first adds an excess of potassium iodide to a 10.0 mL sample at a pH of 3.0–3.5 to produce the anionic PbI42− colored complex, which is exhaustively extracted by the disk that was previously impregnated with cetylpyridinium chloride (CPC). The amount of complex extracted is then determined at 420 nm by a hand-held DRS instrument. A linear calibration plot was obtained for lead(II) concentrations from 0.02–2.50 ppm, with a detection limit of
Dias, Neil C., Fritz, James S., Porter, Marc D.
Passivating Stainless Steel PartsTBMG-198207/01/2004
Maximizing the natural corrosion resistance of parts and components machined from stainless steels. It can make the difference between satisfactory performance and premature failure. Incorrectly performed, passivation can actually induce corrosion.
Annealing Would Improve β" — Alumina Solid ElectrolyteTBMG-114803/01/2003
A pre-operational annealing process is under investigation as a potential means of preventing a sudden reduction of ionic conductivity in a β"—alumina solid electrolyte (BASE) during use. On the basis of tests described below, the sudden reduction of ionic conductivity, followed by a slow recovery, has been found to occur during testing of the solid electrolyte and electrode components of an alkali metal thermal-to-electric converter (AMTEC) cell. This conductivity reduction may be observed quite infrequently; at lower operating temperatures, T<1,073 K, it is not usually observed at all, while at T=1,123–1,173 K, hundreds of hours may pass before conductivity reduction occurs. Only on tests running at higher operating temperatures for thousands of hours is this phenomenon regularly exhibited. The reduction of ionic conductivity would degrade the performance of an AMTEC cell. A pre-operational annealing process would help to sustain performance.
Mixed Conducting Electrodes for Better AMTEC CellsTBMG-114702/01/2003
Electrode materials that exhibit mixed conductivity (that is, both electronic and ionic conductivity) have been investigated in a continuing effort to improve the performance of the alkali metal thermal-to-electric converter (AMTEC). These electrode materials are intended primarily for use on the cathode side of the sodium-ion-conducting solid electrolyte of a sodium-based AMTEC cell. They may also prove useful in sodium-sulfur batteries, which are under study for use in electric vehicles.
Steel Carburizing and Nitriding, Processes forAMSS6090A (Historical)11/21/2002
This specification presents requirements for the carburizing and nitriding of carbon and alloy steels to produce the mechanical properties specified by drawings, detail metal specifications, or other applicable specifications (see 6.3).
AMS E Carbon and Low Alloy Steels Committee
Macroextraction for Purification of Nucleic AcidsTBMG-734205/01/2001
A technique for extracting samples of ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) for use in diagnosing and studying infectious and genetic diseases has been developed. The technique enables the concentration and purification of nucleic acids from large (in comparison with older techniques) volumes of bodily fluids or digested tissues, with minimal nuclease activity and minimal loss of the nucleic acids.
Electrodeposition of Strong Glassy MetalsTBMG-2962911/01/2000
Thin-walled structures made of strong glassy nickel and glassy nickel-cobalt alloys, with tailorable low residual stresses, and with high resistance to permanent plastic deformation, can be formed by use of an electrodeposition process. This process was developed to enable the fabrication of lightweight, high-quality x-ray mirrors that do not undergo unacceptably large distortions when differential thermal contraction upon cooling is used to release the mirror deposits from their electrodeposition mandrels. This process supplants an older pure-nickel electrodeposition process where it was necessary to form relatively thick deposits in order to make them strong enough to resist distortion in the presence of stresses imparted during release.
Sulfur Lamp With CaBr2 Additive for Enhanced Plant GrowthTBMG-217607/01/2000
Calcium bromide can be added to the sulfur filling in a sulfur lamp to increase the emission of red light for enhanced growth of plants. Red light is more efficacious for plant growth than is visible light at shorter wavelengths. The addition of CaBr2 increases the emission at wavelengths in the vicinity of 625 nm, where the quantum efficiency for photosynthesis is close to 1.
Lifetimes of AMTEC Electrodes: Rhodium-Tungsten and Titanium Nitride1999-01-270408/02/1999
The lifetime of an AMTEC electrode is predicted from the rate of grain growth in the electrode. The rate of growth depends on several physical characteristics of each material, including the rate of diffusion of the material on itself. Grain growth rates for rhodium-tungsten and titanium nitride electrodes have been determined, and have been used to predict operating lifetimes of AMTEC electrodes. For lifetimes of 10 years or more, RhxW electrodes may be used at any operating temperature supportable by the electrolyte. TiN electrodes may be used in AMTEC cells only at operating temperatures under 1150 K.
Ryan, M. A., Shields, V. B., Cortez, R. H., Lara, L., Homer, M. L., Williams, R. M.
Slow Reversible and Quasi-Reversible Performance Changes in AMTEC Electrodes and Electrolytes1999-01-270508/02/1999
This paper reports several slow reversible and quasi-reversible processes which occur in the porous electrode/solid electrolyte combination at AMTEC operating temperatures. These processes help to elucidate the evolution of the electrode and electrolyte characteristics with time. They also demonstrate that the atomic constituents of the electrode/electrolyte engage in significant dynamic motion. We report the stability of the sodium beta“-alumina phase in low pressure sodium vapor at 1173K up to 3000 hours, and the decomposition of the sodium meta-aluminate (NaAlO2) phase present at about 1% in the BASE ceramic, which gives rise to transient local increases in the solid electrolyte resistivity due to local micro-cracking. We also report slow apparent morphological changes, possibly surface or grain boundary reconstruction, in TiN and RhW electrodes driven by changes in the local sodium activity.
Williams, R. M., Ryan, M. A., Homer, M. L., Cortez, R. H., Lara, L., Kisor, A., Manatt, K., Shields, V. B.
Potassium AMTEC Cell Performance1999-01-270208/02/1999
AMTEC systems have historically been operated with sodium as the working fluid, in large part because fabrication of beta”-alumina solid electrolyte (BASE) membranes has been substantially easier with sodium than with potassium or other alkali metals1. It has been anticipated that because potassium has a substantially higher vapor pressure for a given temperature, and because the best K-BASE conductivity falls only marginally below that for Na-BASE, potassium AMTEC cells could produce higher power at a given temperature or comparable power at a lower temperature than similar sodium cells. Operation at lower temperatures can reduce materials lifetime or compatibility problems, and for severely heat input constrained systems it could enhance efficiency by reducing parasitic thermal conduction losses. Recently K-BASE tubes have become available as a commercial product2 and conventional experiments to evaluate the performance of complete KAMTEC cells have become much more feasible
Barkan, A., Hunt, T. K., Thomas, B.
Steel Carburizing and Nitriding, Processes forAMSS6090 (Historical)04/01/1998
This specification presents requirements for the carburizing and nitriding of carbon and alloy steels to produce the mechanical properties specified by drawings, detail metal specifications, or other applicable specifications (see 6.3).
AMS E Carbon and Low Alloy Steels Committee
Removable Fillers for VPS Fabrication of Closed ChannelsTBMG-3225503/01/1998
An improved process has been devised for making closed channels (e.g., coolant channels) in a heat-exchanger liner or a similar metal object. The process involves the following steps: First, grooves destined to become closed channels are machined into the object from one surface. Next, a ceramic filler material is troweled into the grooves, made flush with the surface, and allowed to harden by evaporation of water. Next, vacuum plasma spraying (VPS) is used to deposit metal on the exposed metal and filler surface areas to cover the grooves and thereby form closed channels (see figure). Finally, the filler material is removed from the channels. This process satisfies a need for making the channels at lower cost and in less time than is possible by an older process in which the grooves are filled with wax, then a thin layer of copper is electroplated on the exposed metal and wax surface areas, then a thick nickel structural jacket is deposited on the copper.
Efficiency of an AMTEC Recirculating Test Cell, Experiments and Projections92914208/03/1992
The alkali metal thermal to electric converter (AMTEC) is an electrochemical device for the direct conversion of heat to electrical energy with efficiencies potentially near Carnot. The future usefulness of AMTEC for space power conversion depends on the efficiency of the devices. Systems studies have projected from 15% to 35% thermal to electric conversion efficiencies, and one experiment has demonstrated 19% efficiency for a short period of time. Recent experiments in a recirculating test cell (RTC) have demonstrated sustained conversion efficiencies as high as 10.2% early in cell life and 9.7% after maturity. Extensive thermal and electrochemical analysis of the cell during several experiments demonstrated that the efficiency could be improved in two ways. First, the electrode performance could be improved. The electrode for these tests operated at about one third the power density of state of the art electrodes. The low power density was caused by a combination of high series
Underwood, M. L., O'Connor, D., Williams, R. M., Jeffries-Nakamura, B., Ryan, M. A.
Items per page:
1 – 50 of 64