Library

Notes: A novel miniature superconducting quantum interference device magnetometer with direct readout electronics has been developed. A high flux-to-voltage transfer factor of up to 2500 μV/Φ0 is achieved without additional positive feedback (Φ0 is the flux quantum). A flux resolution of 8×10−7 Φ0/Hz1/2, corresponding to a magnetic moment sensitivity of approximately 2×10−20 A m2/Hz1/2, has been measured. This magnetometer can be used to study the dynamic magnetization properties (including nuclear magnetic resonance and magnetic resonance imaging) of micron and submicron size particles and for high-resolution surface magnetometry. © 1997 American Institute of Physics.

Notes: The Chicago mineral-carbonate oxygen isotope fractionation curves have been combined with mineral-water fractionation data for jadeite, zoisite and rutile and new data for grossular-water to provide a set of self-consistent mineral-pair calibrations. The A coefficients in the equation 1000 In α=A× 106T-2 of the new mineral-pair fractionations areJadeite Zoisite Grossular RutileQuartz 1.69 2.00 3.03 5.02Jadeite 0.31 1.34 3.33Zoisite 1.03 3.02Grossular 1.99The isotopic fractionation properties of natural pyralspite garnet [(Ca, Fe, Mg, Mn)3Al2Si3O12] can be approximated by those of the grossular end-member. Appropriate substitutions also yield coefficients for the solid-solution minerals: sodic pyroxene and epidote, e.g. A quartz-sodic pyroxene= 2.75 - 1.06Xjd, A quartz-epidote= 2.00 + 0.75Xpswhere XJd and XPs are the mole fractions of the jadeite and pistacite components, respectively.The new data set is particularly suitable for the geothermometry of metamorphic rocks. δ18O data from minerals of the high-pressure metamorphic rocks of the Sesia Zone of Italy and Cyclades Complex of Greece yield well-constrained mean temperatures of 572 and 478d̀ C, respectively. Type III blueschist metabasalts of the Franciscan Formation of California give mean quartz-garnet temperatures of 354d̀ C.

Notes: Abstract Petrological, oxygen isotope and 40Ar/39Ar studies were used to constrain the Tertiary metamorphic evolution of the lower tectonic unit of the Cyclades on Tinos. Polyphase high-pressure metamorphism reached pressures in excess of 15 kbar, based on measurements of the Si content in potassic white mica. Temperatures of 450–500° C at the thermal peak of high-pressure metamorphism were estimated from critical metamorphic assemblages, the validity of which is confirmed by a quartz–magnetite oxygen isotope temperature of 470° C. Some 40Ar/39Ar spectra of white mica give plateau ages of 44–40 Ma that are considered to represent dynamic recrystallization under peak or slightly post-peak high-pressure metamorphic conditions. Early stages in the prograde high-pressure evolution may be documented by older apparent ages in the high-temperature steps of some spectra.Eclogite to epidote blueschist facies mineralogies were partially or totally replaced by retrograde greenschist facies assemblages during exhumation. Oxygen isotope thermometry of four quartz–magnetite pairs from greenschist samples gives temperatures of 440–470° C which cannot be distinguished from those deduced for the high-pressure event. The exhumation and overprint is documented by decreasing ages of 32–28 Ma in some greenschists and late-stage blueschist rocks, and ages of 30–20 Ma in the lower temperature steps of the Ar release patterns of blueschist micas. Almost flat parts of Ar–Ar release spectra of some greenschist micas gave ages of 23–21 Ma which are assumed to represent incomplete resetting caused by a renewed prograde phase of greenschist metamorphism.Oxygen isotope compositions of blueschist and greenschist facies minerals show no evidence for the infiltration of a δ18O-enriched fluid. Rather, the compositions indicate that fluid to rock ratios were very low, the isotopic compositions being primarily controlled by those of the protolith rocks. We assume that the fundamental control catalysing the transformation of blueschists into greenschists and the associated resetting of their isotopic systems was the selective infiltration of metamorphic fluid. A quartz–magnetite sample from a contact metamorphic skarn, taken near the Miocene monzogranite of Tinos, gave an oxygen isotope temperature of 555° C and calculated water composition of 9.1%. The value of δ18O obtained from this water is consistent with a primary magmatic fluid, but is lower than that of fluids associated with the greenschist overprint, which indicates that the latter event cannot be directly related to the monozogranite intrusion.

Notes: The features of the Intergraph InterMap digital photogrammetric workstation are described. The flexibility of the photogrammetric and image processing capabilities of InterMap allows the system to be fully integrated into a number of fields of special application without the need for a photogrammetric operator, but data handling should still be controlled by a photogrammetric expert. 〈section xml:id="abs1-2"〉〈title type="main"〉Résumé On d'crit dans cet article les l'ments caracteristiques de la station de photogramétrie numérique InterMap d'Intergraph. Si la souplesse des possibilityés offertes par InterMap dans les traitements ďimages ou de photogramétrie permet au systéme de s'intégrer pleinement dans un large domaine ďapplication spéciales sans recourir a'ľaide ďun opérateurphotogrammétre, il n‘en reste pas moins que la manipulation des donnees doit rester sous le contrôle ďun spécialiste de la photogramétrie. 〈section xml:id="abs1-3"〉〈title type="main"〉Zusammenfassung Beschreibung der Charakteristika der digitalen photogrammetrischen Arbeitsstation Inter Map von Intergraph. Die Flexibilität der photogrammetrischen und Bildverarbeitungs-komponenten gestattet die voile Integration des Systems bei einer Anzahl von Sonderanwendungen, ohne daβ dazu ein photogrammetrischer Auswerter erforderlich ist, jedoch sollte die Datenbehandlung weiterhin von einem photogrammetrischen Experten gesteuert werden.

Notes: Seventeen experienced anaesthetists and 15 novices were filmed intubating the trachea of a training manikin. Measurements were made of the distance from manikin's chin to subject's nose and of the angles at the elbow, the shoulder and of the forearm with the horizontal. Trained subjects stood further back (trained: median 43 cm, interquartile range 41–56 cm; novices 35 cm, 26–38 cm; Mann–Whitney U, p 〈 0.01), with a straighter arm (trained elbow angle: 108°, 99–121°; novices': 92°, 88–102°; Mann–Whitney U, p 〈 0.01). Trained subjects tended to hold the laryngoscope closer to the hinge, with a pincer grip; novices were more likely to use a full grip of the handle. Trainers should consider giving novices explicit intructions on how to stand and how to hold the laryngoscope.

Notes: The variation in myofibrillar protein thermostability was compared for various fish species, using differential scanning calorimetry. The tropical fish, catfish (Clarius gariepinus), carp (Cyprinus carpio), Nile perch (Lates niloticus), red snapper (Lutianus sebae), red mullet (Parpeneus barberinus), sea bream (Gymnocranius rivalatus), and cold-water reared trout (Salmo gairdneri) and cod (Gadus morhua) were analysed. Onset temperature of myofibrillar protein denaturation occurred at up to 11°C higher for tropical species (43.5°C, catfish), than cod (32.6°C) at pH 7 and low ionic strength (I). As pH (6.0-8.0) and I (0.05-1.00) were increased, thermal denaturation temperatures of myosins from tropical, but not cold-water, species decreased. Enthalpies of myofibrillar denaturation decreased for all species with increasing pH and I. Only one thermal transition was detected for myosin at pH 6 and low I, increasing to three as pH and I were increased. Changes in thermal characteristics of myosin subunits over iced and frozen storage suggest more rapid deterioration in cold-water than in tropical fish. The differences in myofibrillar stability of fish from different habitat temperatures have implications for the processing and storage of tropical fish.