Coexisting Cardiac and Hematologic Disorders.

Patients with concomitant cardiac and hematologic disorders presenting for noncardiac surgery are challenging. Anemic patients with cardiac disease should be approached in a methodical fashion. Transfusion triggers and target should be based on underlying symptomatology. The approach to anticoagulation management in patients with artificial heart valves, cardiac devices, or severe heart failure in the operative setting must encompass a complete understanding of the rationale of a patient\u27s therapy as well as calculate the risk of changing this regimen. This article focuses common disorders and discusses strategies to optimize care in patients with coexisting cardiac and hematologic disease

High-temperature mass spectrometry - Vaporization of group 4-B metal carbides

The high temperature vaporization of the metal-carbon systems TiC, ZrC, HfC, and ThC was studied by the Knudsen effusion - mass spectrometric method. For each system the metal dicarbide and tetracarbide molecular species were identified in the gas phase. Relative ion currents of the carbides and metals were measured as a function of temperature. Second- and third-law methods were used to determine enthalpies. Maximum values were established for the dissociation energies of the metal monocarbide molecules TiC, ZrC, HfC, and ThC. Thermodynamic functions used in the calculations are discussed in terms of assumed molecular structures and electronic contributions to the partition functions. The trends shown by the dissociation energies of the carbides of Group 4B are compared with those of neighboring groups and discussed in relation to the corresponding oxides and chemical bonding. The high temperature molecular beam inlet system and double focusing mass spectrometer are described

Thermodynamics and kinetics of the sulfation of porous calcium silicate

The sulfation of plasma sprayed calcium silicate in flowing SO2/air mixtures at 900 and 1000 C was investigated thermogravimetrically. Reaction products were analyzed using electron microprobe and X-ray diffraction analysis techniques, and results were compared with thermodynamic predictions. The percentage, by volume, of SO2 in air was varied between 0.036 and 10 percent. At 10 percent SO2 the weight gain curve displays a concave downward shoulder early in the sulfation process. An analytical model was developed which treats the initial process as one which decays exponentially with increasing time and the subsequent process as one which decays exponentially with increasing weight gain. At lower SO2 levels the initial rate is controlled by the reactant flow rate. At 1100 C and 0.036 percent SO2 there is no reaction, in agreement with thermodynamic predictions

The role of NaCl in flame chemistry, in the deposition process, and in its reactions with protective oxides as related to hot corrosion

Sodium chloride is believed to be the primary source of turbine engine contamination that contributes to hot corrosion. The behavior of NaCl-containing aerosols ingested with turbine intake air is very complex; some of the NaCl may vaporize during combustion while some may remain as particulates. The NaCl can lead to Na2SO4 formation by several possible routes or it can contribute to corrosion directly. Hydrogen or oxygen atom reaction with NaCl(c) was shown to result in the release of Na(g). Gaseous NaCl in flames can be partially converted to gaseous Na2SO4 by homogeneous reactions. The remaining gaseous NaCl and other Na-containing molecules can act as sodium carriers for condensate deposition of Na2SO4 on cool surfaces. A frozen boundary layer theory was developed to predict the rates of deposition. The condensed phase NaCl can be converted directly to condensed Na2SO4 by reaction with sulfur oxides and O2. Reaction of gaseous NaCl with Cr2O3 results in the vapor phase transport of chromium by the formation of complex Cr-containing gaseous molecules. Similar gaseous complexes are formed with molybdenum. The presence of gaseous NaCl was shown to affect the oxidation kinetics of Ni-Cr alloys. It also causes changes in the surface morphology of Al2O3 scales formed on Al-containing alloys

Computer programs for the interpretation of low resolution mass spectra: Program for calculation of molecular isotopic distribution and program for assignment of molecular formulas

Two FORTRAN computer programs for the interpretation of low resolution mass spectra were prepared and tested. One is for the calculation of the molecular isotopic distribution of any species from stored elemental distributions. The program requires only the input of the molecular formula and was designed for compatability with any computer system. The other program is for the determination of all possible combinations of atoms (and radicals) which may form an ion having a particular integer mass. It also uses a simplified input scheme and was designed for compatability with any system

The dissociation energy of gaseous titanium mononitride

Dissociation energy of gaseous titanium nitrid

Dissociation energies of some high temperature molecules containing aluminum

The Knudsen cell mass spectrometric method has been used to investigate the gaseous molecules Al2, AlSi,AlSiO, AlC2, Al2C2, and AlAuC2. Special attention was given to the experimental considerations and techniques needed to identify and to measure ion intensities for very low abundance molecular species. Second- and third-law procedures were used to obtain reaction enthalpies for pressure calibration independent and isomolecular exchange reactions. Dissociation energies for the molecules were derived from the measured ion intensities, free-energy functions obtained from estimated molecular constants, and auxiliary thermodynamic data. The bonding and stability of these aluminum containing molecules are compared with other similar species

Mass spectrometric determination of the dissociation energies of titanium dicarbide and titanium tetracarbide

Mass spectrometric determination of dissociation energies of titanium dicarbide and titanium tetracarbid

Social Sector Business Ventures: The Critical Factors That Maximize Success

This paper seeks to help social sector leaders understand the factors that they should consider when launching revenue-generating business ventures. Given that much of the research on social sector business ventures is based on the personal experiences of individual practitioners, there is a wide array of advice for organizational leaders who are thinking about launching business ventures. Consequently, we approach the subject of social sector business ventures in a systematic and analytic way in order to determine what organizational leaders really need to know about launching successful ventures. We introduce a framework called "business in a box" that separates the process of thinking about launching business ventures from the organizational characteristics and dynamics that influence these ventures. We assert that organizational leaders who wish to maximize the success of their business ventures must explore (1) what is "inside" the box (The Business and its Context) to understand the business fundamentals of launching a venture and (2) what is "outside" the box (Assets and Internal Destructive Forces) to understand the forces and dynamics within the organizational context that impact these ventures.This publication is Hauser Center Working Paper No. 43. The Hauser Center Working Paper Series was launched during the summer of 2000. The Series enables the Hauser Center to share with a broad audience important works-in-progress written by Hauser Center scholars and researchers

Spectroscopic measurements of solar wind generation

Spectroscopically observable quantities are described which are sensitive to the primary plasma parameters of the solar wind's source region. The method is discussed in which those observable quantities are used as constraints in the construction of empirical models of various coronal structures. Simulated observations are used to examine the fractional contributions to observed spectral intensities from coronal structures of interest which co-exist with other coronal structures along simulated lines-of-sight. The sensitivity of spectroscopic observables to the physical parameters within each of those structures is discussed