Measurement of release wave speed in shock-compressed polycrystalline alumina and aluminum

Values of release wave speed in shock-compressed polycrystalline alumina and aluminum (2024) have been measured to 400 and 260 kbar, respectively. These values, as well as previous data for aluminum and iron, have been compared with fourth-order finite strain extrapolations of the longitudinal sound speed V_p. For alumina in the pressure range 200–300 kbar and for α iron and ∈ iron the observed release wave speeds fall below any reasonable extrapolation of V_p. In the range 360–400 kbar the data for alumina indicate that M(∂^2M/∂ P^2) ≃ −50 (where M and P are longitudinal modulus and pressure, respectively); this value is in approximate agreement with Graham's ∼200-kbar data on elastic shock compression of single-crystal aluminum oxide. For aluminum the data indicate a value for M(∂^2M/∂ P^2) of 2.7±5.7

The effect of magnetic pinch pressure on boron nitride, cadmium sulfide, graphite, silica glass, and some other materials.

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1970.Bibliography: leaves 129-136.Sc.D

Measurements of the longitudinal modulus of Pierre clay shale at varying strain rates

The propagation speed of finite-amplitude compressional waves of strain-rate 10^3 - 10^4 sec^(-1) in Pierre clay shale have been measured using shock wave techniques. The inferred longitudinal modulus perpendicular to the bedding is approximately a factor of four higher than that measured by others in uniaxial strain tests at strain rates of 1-5 sec^(-1). The present shock wave speeds measured in the laboratory and in-situ finite-amplitude explosive experiments measured by others correlate more closely with field seismic velocities than with laboratory uniaxial strain measurements. Elastic properties of this highly saturated friable material measured parallel to the bedding are less sensitive to sampling disturbances than those measured in the perpendicular direction

THE HUGONIOT ELASTIC LIMIT OF ALON

Abstract. We performed plate impact experiments on the transparent polycrystalline ceramic aluminum oxynitride (A1ON, transparent alumina). From VISAR measurements, the Hugoniot Elastic Limit, GHEL, is 11.0-11.4 GPa with a corresponding yield strength of 1.2-1.5 GPa. A transverse gauge gives a yield strength of 8.7 GPa for a longitudinal stress of 13.9 GPa, which implies that the failed A1ON possesses at least its GHEL strength

How can patients and their physicians contribute to an outbreak investigation? Experiences from a nationwide listeriosis outbreak in Switzerland

QUESTIONS UNDER STUDY/PRINCIPLES: Gathering patient information to contain an outbreak of Listeria monocytogenes is difficult because of the patients' severe illness or death. Extending the range of interviewees to acquire epidemiological data can thus be important to maximise information. METHODS: We built the current analysis on a case-case outbreak investigation conducted during a Swiss listeriosis outbreak between 30 January and 11 May 2014, including 31 patients with confirmed L. monocytogenes infection. We interviewed treating physicians and patients or their next of kin to gather information on clinical aspects, eating habits and food consumption. We compared the different information sources with regards to their potential to provide specific, complete and rapid information on the affected population and their food consumption history. RESULTS: We obtained a 100% response rate among physicians, providing detailed information on the affected population by describing health status, underlying conditions, and signs and symptoms. Detailed information on food history could not be obtained from physicians, making the information vague and unspecific. Less than 50% of patients could be interviewed, limiting our information base. Nevertheless, patient information on the food history was sufficiently detailed and helped to identify the outbreak source CONCLUSIONS: Outbreak investigation teams confronted with limited information from patients and with small numbers of cases can enhance information on the affected population and the outbreak source by combining information from physicians and patients. Physicians provided comprehensive information on signs and symptoms, underlying conditions and the general health status. Patients remain vital to provide detailed information on the food consumption history