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Electromechanical Actuation Systems (EMAS) using advanced state-of-the-art technology offer significant benefits in primary flight control applications. Fighter and attack aircraft present the greatest challenge, but studies have shown feasibility for those applications. The use of samarium cobalt “inside-out” DC motors, solid-state power switching, and microprocessor control of commutation, current, and frequency are the advances that have made EMAS contenders for military aircraft applications. Benefits include elimination of hydraulic systems, improved logistics, increased reliability, and lower life-cycle costs. The studies addressed actuation of canard and rudder control surfaces on supersonic Navy-fighter aircraft.

A concept for an electrochemical reactor acting as a trap for the removal of soot particles from diesel exhaust gas has been developed and presented earlier [1]. Only small scale flat plate samples tested with synthetic exhaust gas was presented. Since then, the sample size has been increased, and test on a diesel engine in a test bench has been carried out. Various concepts for the establishment of a sufficient filtering surface and for the electrical connections have been tested, and the construction of a muffler with an electrochemical reactor installed has been initiated. This is to be on a passenger car for on-road test. The preliminary bench test indicates a soot removal efficiency of 75-90% with no accumulation of soot at the reactor, at temperatures above 250°C. A separate project has been started to evaluate the possibilities of lean NOx removal on a similar reactor. Results from this will be reported separately.

With surging interest in high energy density solid state lithium rechargeable batteries and discoveries of high voltage cathode materials such as LiMn2O4 and LiCO2, it is imperative that useful solid electrolytes possess a voltage window of about 5 volts. These solid electrolytes after being assembled into a cell will be subjected to a dc bias potential equal to cell voltage. The ability of composite electrolytes to withstand the dc potential has been determined, discussed, and presented. The experimental data include linear sweep and cyclic voltammetry measurements. The data are analyzed in terms of dielectric breakdown, ionization, and electrodic reactions.

Lithium ion batteries offer more power and longer cycle life than traditional technologies for many different applications. However, Li-ion batteries are new in the aviation applications and due to the lack of experience they are preventively removed from service before any problems may occur with the battery. This currently makes them unnecessarily expensive. A health diagnostic system needs to be developed and installed in the battery will show the state of health reducing maintenance costs. The purpose of this paper is to show Saft's approach to better understand cell aging through testing using reference electrodes. The aging of the cell anode and cathode will be analyzed under aircraft conditions to determine points of failure. The data acquired will then be used by Global Technology to create a prognostics health management (PHM) model for aviation.

Corrosion behavior of brass CuZn15Fe, brass CuZn30 and aluminum in automotive coolants was studied with electrochemical methods. Two commercial glycols were used in the study. The tests indicate that both glycols provide the metals tested with good corrosion protection. Glycol with conventional inhibitor chemicals prevents corrosion of aluminum even with extensive anodic polarization. Although initiation of pitting could be observed in the same conditions with an inhibitor system based on organic acid technology, it is not very likely to have galvanic corrosion on aluminum by dissolved and deposited copper in automotive coolant systems.

This paper reviews recent work on high power and energy density batteries, which are being studied as possible electrochemical energy storage devices for electric vehicle power-plants. The requirement of high energy density for vehicle applications leads to the selection of battery systems made up of light, highly reactive metals found in the upper left-hand corner of the periodic table for one electrode and the light oxidizers found in the top right-hand corner of the periodic table for the other electrode. Many of these reactive materials will react with water and, hence, water based electrolytes cannot be used in these systems. The parameters relevant to achieving high energy, high power batteries are discussed and several systems presently being studied are reviewed, with particular emphasis on the Li-Cl2M battery.

This work focuses on the electrochemical behavior and corrosion performance of a tri-layer aluminum brazing sheet AA7072/3003/4343 in OY synthetic water. Post-brazed tri-layer sheet samples from four different brazing temperature cycles were subjected to the immersion corrosion test in OY synthetic water for 30 days at 88 ± 2°C to investigate the effect of brazing temperature and zinc diffusion on the corrosion performance of the material. Electrochemical measurement method was also used for examining the corrosion potentials and the galvanic corrosion currents for AA7072, AA3003 and AA4343 both before and after brazing in OY water. The results show that the zinc-containing AA7072 sacrificial layer corroded preferentially during the immersion corrosion tests in OY water.

There are two techniques being considered for carbon dioxide (CO2) removal and concentration for application in a regenerable Environmental Control and Life Support Systems (EC/LSS) aboard the projected Space Station. One uses the continuous Electrochemical Depolarized CO2 Concentration (EDC) technique while the second uses the cyclic absorption and desorption (with steam) from an amine resin bed. While the technologies involved with these techniques are substantially different, each must interface with other elements of a regenerable EC/LSS. This paper presents a comparison of the two competing technologies and includes the design and sizing of the respective subsystems for a Space Station application. The analysis includes identification of assumptions and groundrules with particular attention given to defining subsystem boundaries.

Significant research has been underway for many years to develop technologies to electrochemically power vehicles with limited success. Unfortunately, most technologies fail to achieve theoretical performance and/or are prohibitively too expensive for mass marketed vehicles. Most of the issues with electrochemical technologies can ultimately be attributed to materials issues, whether it is cost, durability, or activity. A broad examination of potential electrochemical technologies is provided identifying key materials issues with each. Included are the results of recent research involving lithium-oxygen batteries. The observations from this research have identified the electrochemical product, lithium peroxide, and its properties to be the most pressing material issue for lithium-oxygen battery. A future research vision is proposed counter to the current research trend of electrocatalyst/electrolyte development.

Regenerable carbon dioxide (CO2)/moisture removal techniques that reduce the expendables and logistics requirements are needed to sustain people undertaking extravehicular activities (EVA) for the Space Station. Life Systems, working with NASA, has been developing the Electrochemically Regenerable CO2 Absorption (ERCA) technology to replace the nonregenerable lithium hydroxide (LiOH) absorber for the, advanced Portable Life Support System (PLSS).(1) During EVA the ERCA uses a mechanism involving gas absorption into a liquid absorbent for the removal and storage of the metabolically produced CO2 and moisture. Following the EVA, the expended absorbent is regenerated on-board the Space Station by an electrochemical concept based on the Life Systems' Electrochemical CO2 Concentrator (EDC) technology. The ERCA concept has the ability to effectively satisfy the high metabolic CO2 and moisture removal requirements of PLSS applications.

Regenerable carbon dioxide (CO2) and moisture removal techniques that reduce expendables and logistics requirements are needed to sustain people undertaking extravehicular activities for the Space Station. Life Systems, working with National Aeronautics and Space Administration has been developing and investigating the ways to advance the Electrochemically Regenerable CO2 and Moisture Absorption (ERCA) technology to replace the nonregenerable solid lithium hydroxide absorber for the advanced Portable Life Support System (PLSS). During extravehicular activities the ERCA technique uses a mechanism involving gas diffusion and absorption into liquid absorbent for the removal and storage of the metabolically produced CO2 and moisture. Following the extravehicular activities, the expended absorbent is regenerated on-board the Space Station by an electrochemical method which restores the CO2 and moisture absorption capabilities of the absorbent.

This paper describes the development of a prototype fluid pumping system for incorporation into a miniaturized flow injection analyzer. The strategy couples the well-established capabilities of reagent-based flow injection analyses (FIA) with our novel concepts for the design of a miniaturized, low-power pumping system, i.e., an electrochemically-driven micropump. The basis of pump actuation relies on the electrochemically-induced surface tension changes at the electrolyte/mercury interface, resulting in a “piston-like” pumping process devoid of mechanically moving parts. We present herein the results from the preliminary performance tests of a miniaturized fluid flow system with the micropump. As described, the flow rates and pumping displacement volumes have been studied as a function of the amplitude and the frequency of the applied voltage waveform.

A high-temperature, low-power electrochemically-driven fluid cooling pump is currently being developed by Lynntech, Inc. With no electric motor and minimal lightweight components, the pump is significantly lighter than conventional rotodynamic and displacement pumps. Reliability and robustness is achieved with the absence of rotating or moving components (apart from the bellows). Lynntech has recently demonstrated the feasibility of long term pump operation at temperatures of up to 100 °C, and extended storage at temperatures as low as -60 °C. Characteristics of the electrochemically-driven pump are described and the benefits of the technology as a replacement for electric motor pumps in mechanically pumped single-phase fluid loops (MPFL), such as that used in the Mars Pathfinder (MPF), is discussed.

OVER THE NEXT SEVERAL YEARS, electrochromic mirrors will be introduced for use on automobiles, initially as interior mirrors and later for the exterior. Electrochromic mirrors have variable reflectivity and this offers an opportunity to select a reflectance level that avoids glare, but that maintains rear vision. Human factors studies can relate driver discomfort to incident glare and the results can be incorporated into a fully automatic mirror whose reflectivity varies dynamically to suit changing driving conditions. In automatic mode, the electrochromic mirror responds appropriately to all driving situations, and mirror operation is transparent to the driver with smooth response and no unexpected change. This paper explains the scientific basis of electrochromism and traces development of the technology to its present applications. Electrochromic mirrors presently available worldwide are reviewed.

Possible active and passive glass is reviewed in terms of “cool automotive glass”. Electrochromics, electrochromic materials, and electrochromic device performance criteria are evaluated as a most promising active glass to control the interior light and heat level of a car. Various automotive applications of electrochromic glasses are also reviewed.

The state of the art in electrochromic materials is briefly reviewed. These materials have potential for architectural and automotive applications for they provide control of radiant solar energy transmission. Optical properties of these materials can be reversibly changed by electrochemical oxidation and reduction. These optically switchable materials can provide control of solar heat load on air conditioning systems, reduce glare for rear view mirrors, and enhance privacy in an automobile. The main features of the electrochromic characteristics of the best-known groups of materials are described. The properties of some of the well-known materials such as WO3, Ni (OH)2, viologens, polyaniline and Prussian Blue are discussed with particular reference to the mechanism of electrochromic reactions.

A transparent, solid-state, electrochromic device is described. It demonstrates deep switching in the near infrared and visible spectral regions and good room temperature cycling stability. The response appears reasonably uniform over a 14 cm x 28 cm area, which gives hope for achieving large parts for cockpit and cabin windows. The reversible darkening of the transparency, controlled by an applied voltage or current, has potential application in aircraft to reduce glare and solar heat load to pilots and passengers. The active material in the device is a thin tungsten oxide film which is incorporated into a complex, multilayered structure, essentially that of a transparent battery. The performance of the window is discussed in terms of its configuration, its similarities with commercial batteries and issues critical to aircraft.

External corrosion of automotive heat exchangers, mainly radiators, has in recent years become a problem in some cases. The reasons for the corrosion attacks are a combination of air pollution on one side and road salting or tropical marine climate on the other. This paper deals with actions taken to improve the corrosion resistance of copper/brass radiators. Rapid corrosion of the tubes due to dezincification which gave early radiator leakages was solved by introducing arsenic and phosphorous containing brass qualities (1). Corrosion of fins and solder has been tackled by different types of coatings (2, 3). Copper strips that are zinc coated before the fin production are a new product for large scale application (4). Solder coated strips have been used since many years but are expensive and heavy. Organic coatings applied on complete radiators have been tested for a couple of years. The black painting that is normally used on radiators does not give any corrosion prevention.

Heat transfer from the flame kernel to the electrodes during the spark ignition process is of interest for predicting the minimum ignition energy at a given engine operating condition. Experiments conducted in a constant volume bomb at near ignition limit conditions with small and large electrode surface areas (comparable to J gap plug), coupled with a phenomenological model, show the lumped heat transfer coefficient to range from 150-200 W/m2 K during the first 3 milliseconds of the ignition period. An additional analytical approach that uses the measured time dependent kernel-electrode contact areas gives reasonable agreement with the experimentally determined heat transfer coefficient and demonstrates that the dominant mechanism is thermal conduction. Heat loss from the flame kernel is comparable to the net ignition energy for the small electrodes after 3 milliseconds while that for the large electrodes is shown to equal the net ignition energy within 800 microseconds.

The units of electric conductivity are defined and the problems associated with conventional instruments are mentioned. The principle of operation of the electrodeless conductivity meter is explained along with manufacturing details. Applications to process control are mentioned and barriers to wider acceptance are discussed.