Browse Topic: Potassium
A unique wristwatch contains multiple modules, including a sensor array, a microfluidic chip, signal processing, and a data display system to monitor chemicals in human sweat. It can continuously and accurately monitor the levels of potassium (K+), sodium (Na+), and calcium (Ca2+) ions.
This specification establishes testing methods for testing chemical composition in nickel- and cobalt-based alloys.
Among the limitations of electric vehicles (EVs) is the lack of a long-lasting, high-energy-density battery that reduces the need to fuel up on long-haul trips. The same is true for houses during blackouts and power grid failures— small, efficient batteries able to power a home for more than one night without electricity don’t yet exist. A major issue is that while rechargeable lithium metal anodes play a key role in how well this new wave of lithium batteries functions, during battery operation, they are highly susceptible to the growth of dendrites — microstructures that can lead to dangerous short-circuiting, catching on fire, and even exploding.
Copper-free non-asbestos-organic (NAO) brake pads have been developed to satisfy the copper content regulations in North America. Copper-free NAO brake pads are required to have a stable friction coefficient owing to the electrification of the control systems, as well as to exhibit improved wear resistance to reduce brake dust emissions. Our previous study indicated that the transfer film formed on the rotor surface affects both the friction coefficient stability and amount of wear. In this study, we investigated how different types of inorganic fillers affect the transfer film formation and its composition in a wear test controlled by temperature. It was confirmed that the main component of the transfer film was iron oxide derived from the rotor. Furthermore, the contained components changed according to the appearance of the rotor surface after each wear test. When the brake pad contained potassium lithium titanate, a transfer film was formed uniformly and stably, the amount of wear was small, and the friction coefficient was stable. In addition, the iron oxide of the transfer film incorporated components such as titanium and barium that were dispersed uniformly. The hardness of the rotor surface after the test was higher than that of the pure iron oxide. This study characterized the composition and physical properties of the transfer film obtained on the rotor surface when using copper-free NAO brake pads. Increased control of the state of this interface may be used to improve the friction characteristics of these systems in the future. Therefore, controlling the transfer film on the rotor surface, which changes during friction, is an important factor to consider when improving brake pads.
Researchers have developed a more efficient, more reliable potassium-oxygen battery with a cathode that stores the energy produced by a chemical reaction in a metal-oxygen or metal-air battery. The battery could make renewable energy sources like solar and wind more viable options for the power grid through cheaper, more efficient energy storage.
Potassium titanate (KT) fibers/whiskers are used as a functional filler for partial replacement of asbestos in NAO friction materials (FMs). Based on little information reported in open literature; its exact role is not well defined since some papers claim it as the booster for resistance to fade (FR), or wear (WR) and sometimes as damper for friction fluctuations. Interestingly, KT fibers and whiskers (but not powder) are proved as carcinogens by the International Agency for Research on Cancer (IARC). However, hardly any efforts are reported on exploration of influence of KT powder and its optimum amount in NAO FMs (realistic composites) in the literature. Hence a series of five realistic multi-ingredient compositions in the form of brake-pads with similar parent composition but varying in the content of KT powder from 0 to 15 wt% (in the steps of 3) were developed. These composites were characterized for physical, mechanical, chemical and tribological performance. Composites were tribo-evaluated on reduced scale prototype (RSP) as well as on full scale brake inertia dynamometer by following ECE R90 and Japanese Automobile Standards (JASO C 406) testing procedure respectively. Optimum content of KT powder was evaluated by multiple objective optimization on the basis of ratio analysis’ (MOORA) method on the basis of several performance parameters such as performance µ, fade µ, recovery µ, % fade ratio, % recovery ratio, wear resistance etc. The friction and wear mechanisms were studies in details based on worn surface analysis. It was concluded that increase in KT amount played important role in improving wear and fade performance. With increase in amount of KT powder, most of the properties improved. Overall 12% KT powder shows best performance.
This paper describes the properties of an engine coolant that uses a potassium propionate solution as base fluid. Although alternatives for ethylene glycol are known, e.g. propylene glycol and glycerin, the use of a salt based coolant for high temperature applications has seldom been considered as a viable option due to the intrinsic corrosiveness of such salt solutions. The salt based coolant offers freezing as well as boiling protection and has thermal properties that allow for usage in standard combustion engines. Volumetric heat capacity and viscosity are very similar to glycol based analogues, while its thermal conductive is substantially higher. Thermal experiments indicate that the potassium propionate coolant is highly effective in suppressing localized boiling phenomena. Due to its chemical nature the coolant has superior oxidation stability. The coolant has the further advantage of being readily biodegradable and has a low toxicity. The coolant contains additionally a tailored additive package that provides corrosion protection for the metallic parts of an engine cooling system. Although current industrial standards cannot be claimed because of compositional requirements imposed by them, laboratory testing has shown that the salt based coolant offers acceptable to excellent results in recognized industrial tests as ASTM D1384, ASTM D4340, ASTM D2570 and ASTM D2809. Similar good results were obtained in the cylinder liner cavitation test (ASTM D7583) indicating that both automotive as well as heavy duty applications are possible. Finally the paper will represent the results obtained in a limited mixed automotive - heavy duty fleet test.
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 system in modern diesel engines. This can take the form of deposits in the fuel filters or within the fuel injectors themselves. Recent work proposed a mechanism whereby sodium contaminated fuel can undergo adverse reactions between the sodium compounds and fuel additives leading to the formation of material that can impede the operation of diesel fuel injectors. This paper presents new work carried out to enhance the understanding of this mechanism and demonstrates that the fate of any sodium contaminant is highly dependent on (i) the fuel additives present in the fuel (ii) the amount of water in the system, (iii) potentially the intensity of fuel/water mixing and (iv) the identity of the sodium salt involved in the reaction. This can lead to sodium accumulating in the water bottoms, forming sodium compounds that go on to plug fuel filters or which may cause injector fouling. The data found may explain the variation in engine test data regarding sodium induced fouling reported in the recent literature.
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 application determines the phase transition temperatures of these solutions, according to their concentration. The spectroscopic tool being portable, its use could be easily conducted on the field, avoiding any sample collections. Furthermore, this spectroscopic tool enables the determination of the amount of de-icers used to generate the solution. This study also highlighted some differences between the freezing curves of different deicers, as well as the possible presence of phases with unknown chemical and mechanical properties, such as the metastable phase potassium formate. Additional lessons related to winter maintenance could be taken, on the shelf-life of these products as an example.
Electro-optic modulators rely on a change in the index of refraction for the optical wave as a function of an applied voltage. The corresponding change in index acts to delay the wavefront in the waveguide. The goal of this work was to develop a high-speed, high-power waveguide-based modulator (phase and amplitude) and investigate its use as a pulse slicer. The key innovation in this effort is the use of potassium titanyl phosphate (KTP) waveguides, making the high-power, polarization- based waveguide amplitude modulator possible. Furthermore, because it is fabricated in KTP, the waveguide component will withstand high optical power and have a significantly higher RF modulation figure of merit (FOM) relative to lithium niobate. KTP waveguides support high-power TE and TM modes — a necessary requirement for polarization-based modulation as with a Pockels cell.
This specification covers pigs of one type of lead alloy used in the making of forming dies.
This elemental space radiator heat pipe is designed to operate in the 700 to 875 K temperature range. It consists of a C–C (carbon-carbon) shell made from poly-acrylonitride fibers that are woven in an angle interlock pattern and densified with pitch at high process temperature with integrally woven fins. The fins are 2.5 cm long and 1 mm thick, and provide an extended radiating surface at the colder condenser section of the heat pipe. The weave pattern features a continuous fiber bath from the inner tube surface to the outside edges of the fins to maximize the thermal conductance, and to thus minimize the temperature drop at the condenser end. The heat pipe and radiator element together are less than one-third the mass of conventional heat pipes of the same heat rejection surface area.
Diesel engines with relatively good fuel economy are known as an effective means of reducing CO₂ emissions. It is expected that diesel engines will continue to expand as efforts to slow global warming are intensified. Diesel particulate and NOx reduction system (DPNR), which was first developed in 2003 for introduction in the Japanese and European markets, shows high purification performance which can meet more stringent regulations in the future. However, it is poisoned by sulfur components in exhaust gas derived from fuel and lubricant. We then developed the sulfur trap DPNR with a sulfur trap catalyst that traps sulfur components in the exhaust gas. High purification performance could be achieved with a small amount of platinum group metal (PGM) due to prevention of sulfur poisoning and thermal deterioration. However, this required the exchange of the sulfur trap catalyst every 40,000 km to maintain a high NOx conversion efficiency, because the sulfur trap catalyst did not have enough sulfur trap capacity. In this paper, we investigated the sulfur trap mechanism, and it was found that the formation of potassium sulfate on the surface of the sulfur trap catalyst during the sulfur trap process inhibited gas diffusion into the surface of the catalyst. We then tried to improve this condition using an oxygen storage material, which could trap sulfur through adsorption without the formation of sulfates. Moreover, the sulfur trap capacity was greatly increased by controlling desorbed SO₂ and transporting it to the sulfur trap material by increasing the temperature. As a result, a system maintaining high NOx conversion efficiency of 80% after 80,000 km mileage accumulation was obtained with our new sulfur trap catalyst concept.
This paper demonstrates the potential of optical sensors in the combustion chamber of a small two-stroke SI engine to detect conditions that hinder an optimal combustion process using emission bands and/or emission lines. The primary focus is on the spectroscopic examination of the combustion radiation emissions cycle-by-cycle. For this purpose, spark-ignition type combustion events, as well as the influence of both the air-fuel-ratio and the fuel type, are investigated on a crank angle resolved basis. Furthermore, an assessment of the radiation emissions of the OH, CH and C2 radicals is made. As a next step, the calculation of a temperature profile inside the combustion chamber is attempted by means of the line-emission-method regarding the thermally excited alkaline metals sodium and potassium. These data enable recognition of diffusion combustion and the detection of inadequate mixture quality.
This paper describes a technique of manufacturing expendable salt cores developed to form undercut shaped aluminum closed deck cylinder block by high pressure die casting (HPDC) process. The salt cores are comprised of Potassium Chloride-Sodium Chloride-Sodium Carbonate-Potassium Carbonate system whose liquidus point is between 873 and 973K. The bending strength of the developed salt core was more than 30MPa. The manufacturing process of the salt cores was the HPDC similar to the process for metallic alloys. This process offered high dimensionality and productivity of the salt cores.
A surface treatment has been found to enhance the performances of carbon nanofibers as electrode materials for electrochemical capacitors in which aqueous solutions of potassium hydroxide are used as the electrolytes. In the treatment, sulfonic acid groups are attached to edge plane sites on carbon atoms.
Cells that contain thin, single-crystal films of photoresponsive organic materials [e.g., meta-nitroaniline (m-NA)] have been invented for use as nonlinear optics and especially as second-harmonic generators. In comparison with crystals of potassium dihydrogen phosphate (KDP) that have been used previously in such applications, the crystals of this invention are smaller and are capable of producing second harmonics of input light at lower input power levels.
Ferrate (VI) salts have been proposed for use in sterilizing water (perhaps also in sterilizing air). The iron in ferrate (VI) salts is in its highest oxidation state (VI), and these salts are extremely strong oxidants. In laboratory experiments, it was shown that treatment of DNA solutions with micromolar concentrations of potassium ferrate (VI) irreversibly inhibits further DNA polymerization and polymerase-chain-reaction (PCR) synthesis. Such treatment does not produce any toxic wastes; instead, what remains after treatment are iron ions, which can be recycled and which, in some applications, are useful as nutrients.
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