____________ _ An intra-aortic balloon which can be inserted percutaneously has become an attractive adjunct in the past few years. The major benefits of this technique are ease and speed of insertion and the lack of need for a surgical cutdown. Early concerns about post balloon removal hemorrhage due to the large catheter size ( 12 French) have largely proven to be unfounded. Early experience ...

The article shows the effect of torsional rigidity of beam elements onto spatial work of bridges, floorings and other plate-ribbed systems It is shown that, in determining the torsional rigidity using existing methods it is necessary to have spatial spiral cracks, but torsional rigidity when normal cracks is not researched. A method is described for determining the torsional rigidity of reinfor...

A new lidar instrument has been developed to measure tropospheric ozone and water vapor at low altitude. The lidar uses Raman scattering of an UV beam from atmospheric nitrogen, oxygen, and water vapor to retrieve ozone and water-vapor vertical profiles. By numerical simulation we investigate the sensitivity of the method to both atmospheric and device perturbations. The aerosol optical effect ...

New Bedford Harbor (NBH), MA, is a Superfund site because of high polychlorinated biphenyl (PCB) concentrations in the sediment. From April 1994 to September 1995, a remedial dredging operation (termed the "Hot Spot") removed the most contaminated sediments (PCB concentrations greater than 4000 microg/g) from the upper harbor. During remediation, a monitoring program assessed the potential envi...

In this work, we use the homogenization theory to investigate the capability of wavy riblet patterns to influence the behaviour of a viscous flow near a ribbed boundary. Starting from perfect slip conditions on the wall, we show that periodic oscillations of wavy riblets in the lateral direction may induce a friction effect in the direction of the flow, contrary to what happens with straight ri...

The present paper reports on the application of Principal Component Analysis (PCA) on the flow and thermal fields generated by the large-eddy simulation (LES) of a square ribbed duct heated by a constant heat flux applied over the bottom surface of the duct. PCA allows to understand the complexity of the resulting turbulent heat transfer process, identifying the flow and thermal quantities whic...

The fluorescent technique is well recommended for in situ water vapor measurements in the upper troposphere, stratosphere and mesosphere on board balloons, highaltitude aircrafts and rockets. New version of the balloon optical fluorescent hygrometer (FLASH-BM) is presented. Special attention is devoted to the calibration procedures, stability, accuracy and precision of the flight instrument. Ne...

An elementary introduction to the inverse problem of radiative transfer as applied to remote measurements of infrared radiation from planetary atmospheres is presented, along with a review of work which has been done on the problem. Particular attention is given to the problems of inferring vertical temperature profiles and water vapor distributions in the earth's atmosphere. The principle meth...