64,114 research outputs found
Letter dated 7 January 1921 from James H. McCann to Edith C. Tallmon
No full textLetter dated 7 January 1921 from James H. McCann, Treasurer for the North China Mission, to Edith C. Tallmon conveying donation for mission work at Lintsing; also a bank receipt and a Treasurer\u27s office record for a $347.95 donatio
[J. C. Keenan prepared to do his laundry]
No full textJ. C. Keenan hold his laundry and a bucket as he heads to the laundry bench. "A friend heading for the wash-bench" and "J. C. Keenan" are written on the back of the photograph.
The photograph was taken during one of McCann's two six-month tours in the Civilian Conservation Corps located in Pineland, Texas during the Great Depression
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
No full textThe prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region
Dwight J. McCann.
No full textR-C of D. McCann. 21 Jan. HR 5, 41-2, v1, 3p. [1436] Transport of annuity goods from Omaha to Fort Laramie in 1866
A laboratory study of seismic velocity and attenuation anisotropy in near-surface sedimentary rocks
No full textThe laboratory ultrasonic pulse-echo method was used to collect accurate P- and S-wave velocity (±0.3%) and attenuation (±10%) data at differential pressures of 5–50 MPa on water-saturated core samples of sandstone, limestone and siltstone that were cut parallel and perpendicular to the vertical borehole axis. The results, when expressed in terms of the P- and S-wave velocity and attenuation anisotropy parameters for weakly transversely isotropic media (?, ? , ?Q, ? Q) show complex variations with pressure and lithology. In general, attenuation anisotropy is stronger and more sensitive to pressure changes than velocity anisotropy, regardless of lithology. Anisotropy is greatest (over 20% for velocity, over 70% for attenuation) in rocks with visible clay/organic matter laminations in hand specimens. Pressure sensitivities are attributed to the opening of microcracks with decreasing pressure. Changes in magnitude of velocity and attenuation anisotropy with effective pressure show similar trends, although they can show different signs (positive or negative values of ?, ?Q, ? , ? Q). We conclude that attenuation anisotropy in particular could prove useful to seismic monitoring of reservoir pressure changes if frequency-dependent effects can be quantified and modelled
Velocity anisotropy and attenuation in shale in under and over pressured conditions
No full textUltrasonic compressional- and shear-wave attenuation measurements have been made on 40, centimetre-sized samples of water- and oil-saturated oolitic limestones at 50 MPa effective hydrostatic pressure (confining pressure minus pore-fluid pressure) at frequencies of about 0.85 MHz and 0.7 MHz respectively, using the pulse-echo method. The mineralogy, porosity, permeability and the distribution of the pore types of each sample were determined using a combination of optical and scanning electron microscopy, a helium porosimeter and a nitrogen permeameter. The limestones contain a complex porosity system consisting of interparticle macropores (dimensions up to 300 microns) and micropores (dimensions 5–10 microns) within the ooids, the calcite cement and the mud matrix. Ultrasonic attenuation reaches a maximum value in those limestones in which the dual porosity system is most fully developed, indicating that the squirt-flow mechanism, which has previously been shown to occur in shaley sandstones, also operates in the limestones. It is argued that the larger-scale dual porosity systems present in limestones in situ could similarly cause seismic attenuation at the frequencies of field seismic surveys through the operation of the squirt-flow mechanism
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Velocities of compressional and shear waves in limestones
No full textCarbonate rocks are important hydrocarbon reservoir rocks with complex textures and petrophysical properties (porosity and permeability) mainly resulting from various diagenetic processes (compaction, dissolution, precipitation, cementation, etc.). These complexities make prediction of reservoir characteristics (e.g. porosity and permeability) from their seismic properties very difficult. To explore the relationship between the seismic, petrophysical and geological properties, ultrasonic compressional- and shear-wave velocity measurements were made under a simulated in situ condition of pressure (50 MPa hydrostatic effective pressure) at frequencies of approximately 0.85 MHz and 0.7 MHz, respectively, using a pulse-echo method. The measurements were made both in vacuum-dry and fully saturated conditions in oolitic limestones of the Great Oolite Formation of southern England. Some of the rocks were fully saturated with oil. The acoustic measurements were supplemented by porosity and permeability measurements, petrological and pore geometry studies of resin-impregnated polished thin sections, X-ray diffraction analyses and scanning electron microscope studies to investigate submicroscopic textures and micropores. It is shown that the compressional- and shear-wave velocities (V-p and V-s, respectively) decrease with increasing porosity and that V-p decreases approximately twice as fast as V-s. The systematic differences in pore structures (e.g. the aspect ratio) of the limestones produce large residuals in the velocity versus porosity relationship. It is demonstrated that the velocity versus porosity relationship can be improved by removing the pore-structure-dependent variations from the residuals. The introduction of water into the pore space decreases the shear moduli of the rocks by about 2 GPa, suggesting that there exists a fluid/matrix interaction at grain contacts, which reduces the rigidity. The predicted Biot-Gassmann velocity values are greater than the measured velocity values due to the rock-fluid interaction. This is not accounted for in the Biot-Gassmann velocity models and velocity dispersion due to a local flow mechanism. The velocities predicted by the Raymer and time-average relationships overestimated the measured velocities even more than the Biot model
The human body as a terrorist weapon: hunger strikes and suicide bombers
No full textThis article argues that a major factor in terrorist acts is an appeal to the actor's own community at an emotional and symbolic level, through acts of sacrifice, particularly self-sacrifice. Although other aims also exist, a prime concern is to recall the actor's home audience to the struggle, because the actor regards himself as acting on their behalf. This utilizes the imagery and symbolism of traditional religion, implying a strong communal and non-material impetus to terrorist acts, rather than rational material calculation, that modern Western man finds difficult to comprehend. It also recalls much classical social theory, which emphasized the central role of religion in community. Self-sacrifice tells an emotional story to the actor's community that is comprehensible to them and will have an emotional appeal to maintaining the community. For the Northern Ireland hunger strikes (possibly analogous to suicide bombers) this is reflected in their appeal solely to a Catholic/nationalist community that equates strongly with ideas of a pre-modern society under threat from a modernizing society. All the hunger strikers were very normal for their community, but left non-Catholics completely unmoved. Consequently there is a need to understand the communal dynamics behind terrorism if one is to effectively counter the threat and that different societies may have different values regarding the individual, community, and life itself. Individual motivations do not provide an adequate explanation for much terrorism and it is a failure to grasp this that severely hinders much counterterrorism
Laboratory estimates of normal and shear fracture compliance
No full textLaboratory estimates of the normal (Bn) and shear (Bt) compliance of artificial fractures
in samples of Jurassic and Carboniferous limestone under wet and dry conditions
are presented. The experiments were performed over a range of confining pressures
(from 5 MPa up to 60 MPa), at ultrasonic frequencies in a Triaxial Hoek cell, using
the pulse-echo reflection technique. The results of this study confirm that the Bn/Bt
ratio of a fracture is dependent on the fluid fill. A value of Bn / Bt of less than 0.05 was
obtained for our wet (honey saturated) sample which is consistent with the prediction
that this ratio should be close to zero for fluid saturated fractures. Values of Bn/Bt for
the dry sample are significantly higher and increase with confining pressure from 0.2
to 0.5. It is suggested that a Bn/Bt ratio of 0.5 is probably a more representative value
to use in modelling studies of gas filled fractures than the common assumption that
Bn ? Bt
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
No full textFirst evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)
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