Fe-Ni Sulphides as Indicators of Alteration in CM Chondrites

This study looks at the sulphide abundance and composition of Fe-Ni sulphide grains in 12 CM chondrites to determine an alteration sequence for these chondrites

A study of the morphology, composition and mineral associations of Fe-Ni sulphides in CM carbonaceous chondrites

A study of the compositional and textural variations between Fe-Ni sulphides in a suite of pristine to extensively aqueously altered CM chondrites, using SEM and EMP techniques

Signature analysis of acoustic emission from graphite/epoxy composites

Acoustic emissions were monitored for crack extension across and parallel to the fibers in a single ply and multiply laminates of graphite epoxy composites. Spectrum analysis was performed on the transient signal to ascertain if the fracture mode can be characterized by a particular spectral pattern. The specimens were loaded to failure quasistatically in a tensile machine. Visual observations were made via either an optical microscope or a television camera. The results indicate that several types of characteristics in the time and frequency domain correspond to different types of failure

Fe-Ni Sulphides within a CM1 clast in Tagish Lake

The composition, abundance and mineral associations of Fe-Ni sulphides within a CM1 clast in Tagish Lake are described, and compared with Fe-Ni sulphides in the carbonate-rich and carbonate-poor lithology of Tagish Lake, as well as Fe-Ni sulphides from CI and CM chondrites

Different degrees of aqueous alteration in sulphides within the CI1 chondrites

Sulphides in four different CI1 chondrites were analysed, to evaluate their composition, texture and morphology. The results reinforce the view that CI1 chondrites could be divided into two subgroups, based on their level of aqueous alteration

Fe isotopic composition of Martian meteorites

In the present work, we have measured iron isotope compositions of a group of Martian meteorites to establish a baseline Fe-isotope fractionation pattern in the case of high-temperature igneous rocks from Mars

An ion probe study of the sulphur isotopic composition of Fe-Ni sulphides in CM carbonaceous chondrites

From the Introduction: The CM chondrites have endured variable degrees of aqueous alteration [1] which has changed their original mineralogy. A detailed study of the petrology and mineralogy of the sulphides in a suite of increasingly aqueously altered CMs, combined with sulphur isotope data measured in situ, can provide clues as to whether differences in the CM group are a result of different degrees of aqueous alteration, or whether they are the result of nebular heterogeneity

Design mobile satellite system architecture as an integral part of the cellular access digital network

The Cellular Access Digital Network (CADN) is the access vehicle through which cellular technology is brought into the mainstream of the evolving integrated telecommunications network. Beyond the integrated end-to-end digital access and per call network services provisioning of the Integrated Services Digital Network (ISDN), the CADN engenders the added capability of mobility freedom via wireless access. One key element of the CADN network architecture is the standard user to network interface that is independent of RF transmission technology. Since the Mobile Satellite System (MSS) is envisioned to not only complement but also enhance the capabilities of the terrestrial cellular telecommunications network, compatibility and interoperability between terrestrial cellular and mobile satellite systems are vitally important to provide an integrated moving telecommunications network of the future. From a network standpoint, there exist very strong commonalities between the terrestrial cellular system and the mobile satellite system. Therefore, the MSS architecture should be designed as an integral part of the CADN. This paper describes the concept of the CADN, the functional architecture of the MSS, and the user-network interface signaling protocols

Semi-Classical Description of Antiproton Capture on Atomic Helium

A semi-classical, many-body atomic model incorporating a momentum-dependent Heisenberg core to stabilize atomic electrons is used to study antiproton capture on Helium. Details of the antiproton collisions leading to eventual capture are presented, including the energy and angular momentum states of incident antiprotons which result in capture via single or double electron ionization, i.e. into [He$^{++}\,\bar p$ or He$^{+}\,\bar p$], and the distribution of energy and angular momentum states following the Auger cascade. These final states are discussed in light of recently reported, anomalously long-lived antiproton states observed in liquid He.Comment: 15 pages, 9 figures may be obtained from authors, Revte