Normal Working Temperature Research Articles

Ionic liquid electrolytes for aluminium secondary battery: Influence of organic solvents

Abstract Physical and electrochemical characteristics of aluminium secondary battery systems based on aluminium anodes, sulfur–carbon cathodes and ionic liquid electrolytes were investigated. Aluminium chloride (AlCl3)/triethylamine hydrochloride (Et3NHCl) ionic liquids were used as the electrolytes. Toluene, benzene, dichloromethane (DCM), and 1,2-dichlorethane (DCE) were tested as the additives to modify the performance of ionic liquid electrolytes. DCM and DCE were found to be the better choices, with 0.2 as the optimized volume ratio of organic solvent to ionic liquid. The additives have functions of reducing the viscosities and elevating the conductivities of ionic liquid electrolytes, while having little influence on the thermal stability of battery system in normal working temperature range. To assess the electrochemical properties of the electrolytes, galvanostatic charge/discharge studies were performed at the cell voltage of 2.4 V to 0.6 V at a constant current discharge of 15 mA/g. The cell exhibits well-defined discharge voltage plateaus near 1.8 V. A discharging capacity of 113.64 mAh/g at the first cycle is obtained for the cell based on DCM-ionic liquid electrolyte, in comparison with 85.23 mAh/g for the cell based on pure IL. The discharging capacity has the highest value of 131.67 mAh/g, and remains 104.69 mAh/g after 40 cycles. This study indicates that the performance of aluminium secondary battery can be greatly improved by adding a small volume of organic additives to the ionic liquid electrolytes.

Effects of additional multiwall carbon nanotubes on impact behaviors of LiNi0.5Mn0.3Co0.2O2 battery electrodes

This work introduces a new mechanically triggered thermal runaway mitigation mechanism. The homogenizer of electrode failure (HEF), multiwall carbon nanotube (MWCNT), was added into LiNi0.5Mn0.3Co0.2O2 (NMC532) battery electrodes. We have studied the effect of the HEF additive on the internal electrical resistance and the mechanical impact resistance of the electrodes. The additional MWCNTs reduced the internal electrical resistance of electrodes before mechanical abuse. Upon mechanical abuse, they could mitigate internal shorting and thermal runaway at normal battery working temperature.

Lower Emissions with DLC Coatings

The results are presented of an investigation into the effects of Diamond-Like Coatings (DLC) on the frictional behaviour of components within the valve train of a production engine. Components from a 40-cylinder, 1.6 litre Peugeot petrol engine were coated with Bekaert's Dylyn Plus, a coating specifically aimed at high volume automotive applications and with properties that can be tuned precisely to match the customer's needs. Tests were run on an electrically driven test rig using coated and uncoated mechanical and hydraulic tappets. The results were measured at 20, 50, 80 and 120degreesC where 20degreesC was considered to be a normal start-up engine temperature and 80 - 120degreesC the normal working temperature for an engine. The results for torque reduction are presented graphically. In the low rpm range friction reduction, and therefore energy requirement, was reduced by 24 per cent but this decreased with higher rpms. It is estimated that a reduction in fuel consumption of 1-2 per cent could be achieved implying a reduction in carbon dioxide emission of 2-3 per cent. It is suggested that the benefits of DLC coating would be most beneficial to smaller petrol cars.

Electrochemical synthesis of Fe–Mo and Fe–Mo–Pt alloys and their electrocatalytic activity for methanol oxidation

Electroplating of Fe–Mo and Fe–Mo–Pt alloys has been carried out using suitable plating bath solutions and working conditions. The deposits were characterized by SEM, XRD, TEM, EDAX, XPS and Polarization techniques. New phases appeared on heat treatment of the coatings. The composition (Fe–Mo) of the coatings and oxidation states of the alloying elements varied from the surface to the bulk of the material. The coatings acted as novel electrode materials with good electrocatalytic activities (low overpotentials) and good corrosion resistance for the anodic oxidation of methanol in H 2SO 4 at normal working temperature. The good corrosion resistance of the Fe–Mo alloy is accounted for by the existence of an oxyhydroxide passive film on the surface. The electrocatalytic activity of the Fe–Mo–Pt alloy is considerably higher when compared to the Fe–Mo alloy and Fe alone

Microstructure, surface and electrochemical studies of electroless Cr–P coatings tailored for the methanol oxidative fuel cell

Cr–P is a new material of great importance as a decorative coating with nickel in automobile industries. Electroless plating of Cr–P alloy has been carried out using a suitable plating bath solution and working conditions. The deposit is characterized by X-ray diffraction, transmission electron microscopy, energy-dispersive X-ray diffraction, X-ray photoelectron spectroscopy and polarization techniques. New phases appear on heat treatment of the coating. The composition (Cr/P) of the coating and the oxidation states of alloying elements vary from the surface to the bulk of the material. The coatings acted as a novel electrode material with good electrocatalytic activity (low overvoltage) and good corrosion resistance for anodic oxidation of methanol in H2SO4 at normal working temperature. The good corrosion resistance of the Cr–P film is accounted for by the existence of a double oxyhydroxide passive film on the surface. The electrocatalytic activity of Cr–P is very high when compared with chromium alone.

Trace Element Determination in Diesel Particulates by Total-Reflection X-Ray Fluorescence Analysis

Particulate matter of Diesel emissions collected from diluted exhaust during standard test runs with two Diesel fuels of different sulfur content was analysed by total-reflection X-ray fluorescence (TXRF). The trace elements determined were S, Ca, Cr, Mn, Fe, Ni, Cu, Zn and Pb. Additionally, some filter materials were tested with respect to their applicability for sample collection. Quartz fibre filters were found to be most suitable, both from a technical and a chemical point of view. A clear reduction of total particulate emissions during the whole test was observed when the fuel with very low sulfur content was used. In addition, it was found that the wear metal content of particulate matter emitted by a cold engine was higher than that observed during normal engine working temperature.

Ambient temperature dependent heating power control for motorola micro CO gas sensor

Gas sensors suffer from stability and reproducibility. In this paper, a new method of driving micro gas sensors to get reproducible behaviour under different ambient conditions is proposed. The new method consists of a proportional pattern of temperature modulation with alternating high and low power-heating pulses depending upon the effect of ambient temperature on sensing conductance of the micro gas sensor. The sensor conductance was very sensitive to changes in ambient temperature and was almost insensitive to changes in relative humidity in the working range of 50 to 95%. The sensor exhibited a reproducible CO gas response with sequential pulse technique and the measured conductance at the end of a low power pulse varied linearly with the square root of concentration of CO gas up to 400ppm. With the correct proportional power control, the sensor exhibited drift free, reproducible and almost constant CO gas response characteristics over the normal working temperature range of 25 to 40°C.

Properties of a Non-Film Forming Latex in Ceramic Tile Mortar

Abstract Latexes currently used for modifying portland cement contribute many property improvements to mortar and concrete. Many different polymers are used to make these latexes, but all have one thing in common: they form a film at normal working temperatures. It is the formation of this film that is generally understood to be critical to the performance of these latexes in portland cement and responsible for certain of the property improvements in the hardened mortar and concrete. Contrary to this accepted understanding, an experimental latex has been developed for use in portland cement that does not form a film at room temperature. Instead, the latex particles maintain their integrity as spheres after the portland cement mixture hardens and still provides property improvement in the hardened mixture. The lack of film-formation also eliminates the stickiness during finishing and the surface crusting from air-drying that are typical of the film-forming latexes used in portland cement. Tests of this latex were conducted on mortar with ceramic tile and compared to mortars using standard film-forming latexes. Workability, compressive strength, and shear bond of the mortars were evaluated. In addition, flexural bond strength of tile-to-plywood and cement backerboard was measured using a new test procedure.

4945302 Process and a circuit board for performing tests during burn-in of integrated semi-conductor circuits

A process for the burn-in of either or both analog and digital integrated circuits where the various functions in the individual circuits are tested continuously and individually, while the circuits are cyclically caused to work at extreme temperatures, and the test is stopped when a predetermined error rate has been reached. To perform the process, a circuit board comprises, in addition to the circuits tested at intermittent elevated temperatures, also auxiliary circuits for data collection and data compaction, said circuits being present at a constant normal working temperature during the burn-in sequence.

Temperature dependence of the R0A product of PbTe Schottky diodes

Evidence is presented that the incremental resistance area ( R 0 A) product of PbTe infrared detectors at their normal working temperature (77 K) is limited by tunneling currents. The R 0 A product of Pb Schottky barriers on PbTe with carrier concentrations in the low 10 17 cm −3 range has been measured and calculated by assuming simple band-to-band tunneling. The exponential dependence of the tunneling current on the carrier concentration implies a strong limitation on tolerable variations in the carrier concentration in order to achieve R 0 A products within the same order of magnitude among the individual detectors of an infrared detector array.

Radiation and temperature stability of ferrites with rectangular hysteresis characteristics

1. Metallic low coercive force materials with rectangular hysteresis characteristics are less stable to radiation than ferrites. 2. Irradiation of grade 50NP and 79NM alloys with an integrated flux of the order of 1018 neutrons/cm2 produces appreciable changes in the magnetic saturation and coercive force. 3. Irradiation of ferrite cores made from grade N-44 and grade N-85 ferrites with an integrated flux of 1018 neutrons/cm2 does not result in any observable changes in properties. 4. The normal working temperatures for grade N-44 and grade N-85 ferrite cores are 70–80 and 60–70° respectively. 5. The effect of the self-heating temperature of the ferrite cores depends on the magnitude of the magnetic induction and the remagnetization frequency. 6. The method developed for determining the core self-heating temperature under high frequency remagnetization conditions is an improvement on the indirect method.

Corrosion Notebook

Putty with a difference. British Insulated Callender's Cables Ltd. market a new versatile type of putty called Bicaseal, for sealing, repairing, jointing and waterproofing a variety of materials including metal, wood, glass, ceramics and some plastics. It has been developed by the Accessories Division, Prescot, and consists of a two‐part (resin and hardener) mix supplied in stick form. It is easy to work, using equal lengths of both sticks, and begins to set as soon as it is mixed, setting hard enough for most practical purposes in about 1½ hr. in normal working temperatures. When fully cured it can be drilled, tapped, filed or cut. It will set under water.

The lives of electron microscope filaments

The lives of the tungsten filaments used in electron microscopes can be limited by the thermal evaporation of the metal, or by chemical attack, in inferior vacua. The lives to be expected when either cause is dominant are calculated for a variety of operating conditions. Comparison of these calculated values with measured lives shows that thermal evaporation limits lives in microscopes used at high magnifications. The life limited by evaporation decreases as the temperature and thermionic emission increase, and so corresponding values of filament life and ideal gun output brightness (thermionic emission density per unit solid angle) have been calculated for normal working temperatures, in order that a compromise may be made.