Operator matrices on topological vector spaces

A series of basic summability results are established for matrices of linear and some nonlinear operators between topological vector spaces.     

High spatial resolution multi-site EPR oximetry. The use of convolution-based fitting method

We describe a new method to enhance the spatial resolution of multi-site electron paramagnetic resonance (EPR) oximetry. The method is suitable for any shape (density distribution function) of a solid paramagnetic material implanted in tissue. It corrects distortions of lineshapes caused by the gradient and thus overcomes limitations of previous multi-site EPR oximetry methods that restricted the ratio of the particle size to the distance between sites. The new method is based on consecutive applications of magnetic field gradients with the same direction but with a different magnitude and uses a convolution-based fitting algorithm to derive Lorentzian EPR linewidths of each individual peak of the EPR spectrum. The method is applicable for any particulate EPR oxygen sensitive materials whose EPR spectra can be approximated by a Lorentzian function or a superposition of Lorentzian functions. By incorporating this model of the lineshape in the data processing, we are able to decrease significantly the number of parameters needed for the calculations and to recover the oxygen concentration, even from quite noisy spectra. We (i) describe our method and the data-processing algorithm, (ii) demonstrate our approach in model and in vivo experiments, and (iii) discuss the limitations.     

Tests on microconcrete model of hyperbolic cooling tower

In the past 18 years following the collapse of three cooling towers on November 1, 1965 in Ferrybridge, England, a considerable interest has developed in determining the buckling behavior of these thin-walled shells under the loadings normally encountered. An extensive number of theories exist attempting to predict buckling response and failure. Numerous tests on small, elastic models of metals or plastics have also been reported. However, little work has been reported on the physical testing to failure of concrete models. This paper describes work on the construction, instrumentation and testing of a microconcrete model of a hyperboloid of revolution proportioned to exhibit buckling prior to collapse. This model is the first in a series of models which will be constructed and tested with a variety of load and support configurations. The shell model was tested to failure under the action of uniform pressure (vacuum loading). The failure was of a local nature so the model was repaired and tested a second time to failure. The results of these tests showed good agreement with membrane theory (modified to account for geometric imperfections) for measured strains but the buckling mode of failure was of an unexpected type. Paper was presented at 1982 SESA Fall Meeting held in Hartford, CT on November 7–10, 1982.     

First direct measurement of the parity-violating coupling of the Z0 to the s quark

We present the first direct measurement of A(s), the parity-violating coupling of the Z0 boson to the strange quark, using approximately 550 000 e(+)e(-)-->Z0-->hadrons events recorded by the SLC Large Detector with a polarized e(-) beam. We tagged Z0-->s&smacr; events by the absence of B or D hadrons and the presence in each hemisphere of a high momentum K+/- or K(0)(s). Fitting the polar angle distributions of the strangeness-signed thrust axis gave A(s) = 0.895+/-0.066(stat)+/-0.062(syst). The analyzing power and uu+d&dmacr; background were constrained using the data, greatly reducing any model dependence.     

Precise measurement of the b-quark fragmentation function in Z0 boson decays

We have developed a new technique for inclusive reconstruction of the energy of B hadrons. The excellent efficiency and resolution of this technique allow us to make the most precise determination of the b-quark fragmentation function, using e(+)e(-)-->Z0 decays recorded in the SLAC Large Detector experiment. We compared our measurement with the predictions of a number of fragmentation models. We excluded several of these models and measured the average scaled energy of weakly decaying B hadrons to be = 0.714+/-0. 005(stat)+/-0.007(syst)+/-0.002 (model dependence).     

An apparatus for tensile testing of concrete

This paper describes a test fixture and alignment jig used for testing small concrete or rock cylinders in uniaxial tension. The fixture may be easily modified to test cube specimens and is adaptable for use in any standard universal testing machine. A testing procedure is described and results presented for 3 in. × 6 in. (76 mm × 152 mm) concrete cylinders. The main virtues of the fixture are its ease of construction, simple alignment procedure for the test specimen, and accuracy comparable to that obtained from the standard compression test of concrete cylinders.