Matrix Isolation Infrared Spectra of Hydrogen Halide and Halogen Complexes with Nitrosyl Halides

Matrix isolation infrared spectra of nitrosyl halide (XNO) complexes with HX and X2 (X = Cl, Br) are presented. The r elative frequency shifts of the HX mode are modest (ClNO · H-Cl, !\u27:..:v/v = = - 0.045; BrNO·H-Br, Av/v = ·-0.026), indicating weak hydrogen bonds 1-3 kcal/mo!. These shifts are accompanied by significant shifts to higher frequencies in the XN-0 stretching mode (CIN-O·HCl, Av/v = +0.016; BrN-O·HBr, Av/v = +0.011). Similar .;hifts were observed for the XN-0 · X2 complexes (ClN-0 Cl2, Aviv = +0.009; BrN-0-Br2, Av/v = +0.013). In all four complexes, the X- NO stretching mode relative shift is opposite in sign and about 1.6 times that of the NO stretching mode. These four complexes are considered to be similar in structure and charge distribution. The XN- 0 frequency shift suggests that complex formation is accompanied by charge withdrawal from the NO bond ranging from about .04 to .07 electron charges. The HX and X2 molecules act as electron acceptors, drawing electrons out of the antibonding orbital of NO and strengthening the XN-0 bond. The implications of the pattern of vibrational shifts concerning the structure of the complexes are discussed

REENGINEERING: A FRAMEWORK FOR EVALUATION AND CASE STUDY OF AN IMAGING SYSTEM

Reengineering or business process redesign has become very popular. This paper presents a framework for comparing and evaluating reengineering efforts. The framework is applied to a case study of the reengineering of the securities processing function at Merrill Lynch. The paper compares the old and new process at Merrill. The new process features image capture, character recognition and extensive redesign. The reengineering effort has had a substantial payback for the firm.Information Systems Working Papers Serie

RE-ENGINEERING: A FRAMEWORK FOR ANALYSIS AND CASE STUDY OF AN IMAGING SYSTEM

Re-engineering or business process redesign has become very popular. This paper presents a clear description of re-engineering and contrasts it with incremental change in systems. The paper also develops a framework for comparing two related systems. The framework is applied to a case study of the re-engineering of the Merrill Lynch Securities Processing System. This system features image processing, character recognition and extensive process redesign. The re-engineering effort has had a substantial impact on the firm.Information Systems Working Papers Serie

Increased cytotoxicity of oxidized flame soot

AbstractCombustion–generated particles released into the atmosphere undergo reactions with oxidants, which can change the particles’ physiochemical characteristics. In this work, we compare the physical and chemical properties and cellular response of particles fresh from a flame with those oxidized by ozone and nitrogen dioxide. The reaction with ozone and nitrogen dioxide does not significantly modify the physical characteristics of the particles (primary particle size, fractal dimension, and surface area). However, oxidation affects the chemical characteristics of the particles, creating more oxygen and nitrogen containing functional groups, and increases their hydrophilicity. In addition, oxidized soot generates more reactive oxygen species, as measured by the dithiothreitol (DTT) assay. Furthermore, oxidized soot is 1.5 – 2 times more toxic than soot that was not reacted with ozone, but the inflammatory response, measured by interleukin–8 (IL–8) secretion, is unchanged. These results imply that combustion–generated particles released into the atmosphere will have an increased toxicity on or after high ozone days

Search for correlation effects in linear chains of trapped ions

We report a precise search for correlation effects in linear chains of 2 and 3 trapped Ca+ ions. Unexplained correlations in photon emission times within a linear chain of trapped ions have been reported, which, if genuine, cast doubt on the potential of an ion trap to realize quantum information processing. We observe quantum jumps from the metastable 3d 2D_{5/2} level for several hours, searching for correlations between the decay times of the different ions. We find no evidence for correlations: the number of quantum jumps with separations of less than 10 ms is consistent with statistics to within errors of 0.05%; the lifetime of the metastable level derived from the data is consistent with that derived from independent single-ion data at the level of the experimental errors 1%; and no rank correlations between the decay times were found with sensitivity to rank correlation coefficients at the level of |R| = 0.024.Comment: With changes to introduction. 5 pages, including 4 figures. Submitted to Europhys. Let

System-Specific Differences in Behavior Regulation: Overrunning and Underdrinking in Molar Nondepriving Schedules

In two experiments we tested the molar regulation prediction that animals adjust schedule performance to reduce deviations from baseline response totals. Both experiments constrained the baseline drink-burst length under molar nondepriving schedules but allowed rats to continue running without drinking. In Experiment 1, rats were required to run in order to drink. In Experiment 2, water was delivered independently of running by fixed-time (FT) schedules. Under the run-to-drink contingency, rats exceeded their baseline amounts of running (overrunning) but failed to maintain their baseline water intake (underdrinking). The total amount of running that did not lead to drinking approximated baseline running. Under the FT schedules, rats again underdrank, but total running approximated baseline. These results do not support previous studies that have shown molar equilibrium effects under nondepriving reciprocal schedules. We conclude that (a) contingent running may not substitute for independent running; (b) intermittent access to water reduces the total instigation for drinking; (c) molar regulation differs under reciprocal and nonreciprocal schedules; and (d) more dynamic, system-specific regulatory models need to be developed. Molar behavior regulation models

Matrix Isolation Infrared Spectra of Hydrogen Halide and Halogen Complexes with Nitrosyl Halides

Matrix isolation infrared spectra of nitrosyl halide (XNO) complexes with HX and X2 (X = Cl, Br) are presented. The r elative frequency shifts of the HX mode are modest (ClNO · H-Cl, !\u27:..:v/v = = - 0.045; BrNO·H-Br, Av/v = ·-0.026), indicating weak hydrogen bonds 1-3 kcal/mo!. These shifts are accompanied by significant shifts to higher frequencies in the XN-0 stretching mode (CIN-O·HCl, Av/v = +0.016; BrN-O·HBr, Av/v = +0.011). Similar .;hifts were observed for the XN-0 · X2 complexes (ClN-0 Cl2, Aviv = +0.009; BrN-0-Br2, Av/v = +0.013). In all four complexes, the X- NO stretching mode relative shift is opposite in sign and about 1.6 times that of the NO stretching mode. These four complexes are considered to be similar in structure and charge distribution. The XN- 0 frequency shift suggests that complex formation is accompanied by charge withdrawal from the NO bond ranging from about .04 to .07 electron charges. The HX and X2 molecules act as electron acceptors, drawing electrons out of the antibonding orbital of NO and strengthening the XN-0 bond. The implications of the pattern of vibrational shifts concerning the structure of the complexes are discussed