Superior Low-temperature Performance Research Articles

Effect of Aging on the Low-Temperature Properties of Asphalt Mixture

This article studies the low-temperature anti-cracking properties of plain asphalt mixtures and rubber-modified asphalt mixtures at different aging condition. Laboratory flexural test was conducted on the beam specimens of plain asphalt mixtures and rubber-modified asphalt mixtures. Experiment results indicate that rubber-modified asphalt mixtures have superior low-temperature anti-cracking performance than that of plain asphalt mixtures. Compared with the short term oven aging test, the long term oven aging test has more significant effect on the low-temperature anti-cracking of the mixture. In order to better represent the low-temperature anti-cracking of in-service aging asphalt pavement, the long term oven aging test should be used to appraise the low-temperature anti-cracking of asphalt pavements in china.

Low temperature behaviour of TiO 2 rutile as negative electrode material for lithium-ion batteries

High surface nanosized rutile TiO 2 is prepared via a sol–gel method from an ethylene glycol-based titanium-precursor in the presence of a non-ionic surfactant, at pH 0. Its electrochemical behaviour has been investigated at low temperature using two different potential windows. Typically, the potential window of the rutile system is 1–3 V but the use of an enlarged potential window (0.1–3 V), leads to an excellent reversible capacity of 341 mAh g −1 which is comparable to graphite anodes. The electrochemical performance was investigated by cyclic voltammetry and galvanostatic techniques at temperatures ranging from −40 to 20 °C. Nanosized TiO 2 exhibits excellent rate capability (341 mAh g −1 at 20 °C, 197 mAh g −1 at −10 °C, 138 mAh g −1 at −20 °C, and 77 mAh g −1 at −40 °C at a C/5 rate) and good cycling stability. The superior low-temperature electrochemical performance of nanosized rutile TiO 2 may make it a promising candidate as lithium-ion battery material.

Basics: Current base oil quality and technological options for its improvement— an Overview

AbstractRecent technological developments have revolutionised the lubricant industry by spurring a widespread quality improvement in both base oils and additives, giving superior finished lubricants. The upgrading of base oils is being brought about by more demanding requirements from original equipment manufacturers (OEMs), by government regulations, and through consumer awareness, environmental concerns, decreasing supply of high‐quality lubricant‐bearing crudes, and expanding markets worldwide.Present‐day lubricant demand is for maximum oxidation stability, superior low‐temperature performance, low volatility, and improved additive response, which are difficult to achieve through conventional processing. Conventional solvent lubricant refining produces base oils with a viscosity index (VI) of 100 with a fair amount of sulphur and aromatics, i.e., Group I base oils only. The current requirements of high‐performance base oils can conveniently be met through the hydroprocessing route. Depending upon the severity level, hydroprocessing is able to produce base oils of VI 95–110, in addition to low sulphur and high saturates content (Group II and Group III) by transforming the undesirable molecules into more useful structures. In countries such as India, a hybrid approach offers a technical solution to meet current demands for lubricant quality. This approach can be implemented in existing lubricant refineries without entailing major changes in refinery configuration, besides being cost‐effective.This paper describes the current requirements of modern lubricants in relation to API Groups and trends in these, and describes a sequence of technologies involving solvent refining, a cost‐effective hybrid scheme, and more recent hydroprocessing that allows a cost‐effective upgrading of Group I refining process. A case study is given that discusses the adoption of the hybrid scheme in Indian refineries.

Lithium ion batteries for Mars exploration missions

The desired performance characteristics and physical requirements of spacecraft batteries for planetary exploration are reviewed, particularly with respect to surface landers and rovers intended for near-future Mars missions. The use of lithium ion batteries is justified in terms of significant savings on mass and volume, and more importantly of superior low temperature performance deemed essential in the Mars lander and rover missions. Use of these batteries in planetary orbiters may require further improvements in their cycle life, especially at low depths of discharge. Various strategies currently being adopted to prolong the cycle life for orbiter applications, as well as, for extending their operating range down to temperatures as low as −30°C for more imminent Mars lander and rover missions are briefly discussed.

Flexomer™ Polyolefins-a Unique Class of Ethylene Copolymers for Low Temperature Film Applications

FLEXOMERTM polyolefins, referred to as very low density poly ethylenes (VLDPEs), are manufactured by a gas-phase, fluid bed process tech nology. Commercially available products typically range in density from 0.880 to 0.912 g/cc. The growing family of VLDPEs includes both narrow and broad molecular weight distribution polymers. The low crystallinity of these resins results in energy absorbing characteristics that yield outstanding low tempera ture impact properties. The lower brittleness temperature of VLPDE products provides superior low temperature performance when compared with ethylene vinyl acetate (EVA) and linear low-density polyethylene (LLDPE) copolymers.