Isomerization and Decomposition of Chloromethylacetylene

The isomerization and thermal decomposition of chloromethylacetylene (CMA) has been studied with two shock tube techniques. The first experiment (Jerusalem) utilizes single-pulse shock tube methods to measure the isomerization rate of CMA to chloroallene. In addition, equilibrium constants can be estimated at ∼1200 K. The second experiment (Argonne) monitors Cl-atom formation at temperatures above ∼1150 K. Absolute yield measurements have been performed over the 1200–1700 K range and indicate that two decomposition channels contribute to CMA destruction, namely, Cl fission and HCl elimination. The results show that the branching fraction between processes is temperature dependent. Therefore, direct Cl-atom fission is accompanied by molecular elimination, undoubtedly giving HCl and one or more isomers of C₃H₂. MP2 6–31G(d,p) ab initio electronic structure calculations have been used to determine vibration frequencies and moments of inertia for three C₃H₃Cl isomers. Using these quantities, the experimental equilibrium constants required that ΔH⁰₀(CH₂Cl–C≡CH ⇌ CHCl=C=CH₂) = −;0.24 kcal mole⁻¹. A potential energy surface pertinent to the present system has been constructed, and RRKM calculations have been carried out in order to explain the isomerization rates. The isomerization data can be explained with E₀ = 52.3 kcal mole⁻¹ and 〈ΔE_down〉 = 225 cm⁻¹. Subsequent semi-empirical Troe and RRKM-Gorin modeling of the Cl atom rate data require E₀ = (67.5 ± 0.5) kcal mole⁻¹ with a 〈ΔE_down〉 = (365 ± 90) cm⁻¹. This suggests a heat of formation for propargyl radicals of (79.0 ± 2.5) kcal mole⁻¹.     

Optimization of on-chip ESD protection structures for minimal parasitic capacitance

Diodes are key components in on-chip electrostatic discharge (ESD) protection design. As the operating frequency of the microchip being protected against the ESD continues to increase, the parasitic capacitance associated with the diodes in the ESD structure starts to impose problems for RF operation. This paper presents a systematic approach to optimize the diode structure for minimal parasitic capacitance based on the requirements of breakdown voltage and heat dissipation. Device simulator Atlas with mix-mode simulation capability is calibrated against measurement data and used to carry out the optimization. An optimized diode structure with a parasitic capacitance of less than 30 fF at an operating frequency of 10 GHz and ESD charging voltage of 1 kV has been suggested. Furthermore, a case study to implement and optimize the ESD protection structure based on an existing 0.13-μm CMOS technology has been presented and verified.     

Treatment process factors and satisfaction with drug abuse treatment.

Examined treatment satisfaction (TS) in relation to treatment outcomes (i.e., tenure and relapse for opioid use) and client and treatment variables in 532 methadone maintenance clients in a data system by M. Allison et al (1982). Satisfaction data were limited to the 1st 3 mo in treatment. Most Ss stated that the treatment had helped them to some degree with their drug problem or that they were at least somewhat satisfied with treatment. About three-quarters of the clients felt that the treatment had helped them at least somewhat with other nondrug problems. Overall, results suggested that TS measured early in treatment does not have strong direct effects on during-treatment-outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Proximity printing of chrome masks

We have investigated the application of proximity printing to the copying of chrome masks used for integrated circuit fabrication. The mask blanks were coated with various positive and negative photoresists. When plotting the difference in width between etched lines on the print and the corresponding feature on the mask as a function of the separation, one observes fluctuations due to the movement of the diffraction peaks in the optical image. For the negative resist, the averaged difference in width is approximately constant to separations of 25 micrometer (μm), while for positive resists it changes monotonically with increasing gap spacing. The measured results are compared with calculations using a model of the resist exposure and development and good agreement is obtained. On the basis of these results we conclude that proximity printing would be difficult to apply to mask replication, but that it has considerable promise for replicating 10X step-and-repeat reticles.     

Comments on "The Paramorphic Representation of Clinical Judgment."

Hoffman's (see 34: 7779) position concerning the independent contribution of a variable in the judgment process is examined by presenting several empirical examples. It is concluded that the concept of relative weight will not provide any information about the independent contribution of a predictor. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis of rectangular waveguide-gratings for amplifierapplications

A slow-wave structure composed of a grating inside a rectangular waveguide is analyzed. This type of slow-wave structure is examined for use in a low-voltage amplifier application with a sheet electron beam. Dispersion curves, mode field profiles, and taper designs for the waveguide-grating are presented. The amplifier application places stringent requirements on the taper sections that match the smooth waveguide to the waveguide-grating with minimal reflection     

Judgments of consensus during group discussion.

6 groups of Ss held discussions during which the individuals' opinions and estimates of the group consensus were privately taken on various issues. "The degree of estimation accuracy achieved was not noticeably different from the accuracy found by other investigators under conditions of no discussion." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quantifying Software Validity by Sampling

The point of all validation techniques is to raise assurance about the program under study, but no current methods can be realistically thought to give 100% assurance that a validated program will perform correctly. There are currently no useful ways for quantifying how 'well-validated' a program is. One measure of program correctness is the proportion of elements in the program's input domain for which it fails to execute correctly, since the proportion is zero i.f.f. the program is correct. This proportion can be estimated statistically from the results of program tests and from prior subjective assessments of the program's correctness. Three examples are presented of methods for determining s-confidence bounds on the failure proportion. It is shown that there are reasonable conditions (for programs with a finite number of paths) for which ensuring the testing of all paths does not give better assurance of program correctness.     

Area decomposition for electromechanical models of power systems

Coherency and time scale properties of power system models are shown to be related by the dichotomic solution of a matrix Riccati equation. A grouping algorithm is proposed which reduces the area decomposition problem to obtaining a basis for the slow subsystem and performing a Gaussian elimination. Since the slow coherency measure allows for a lack of coherency in fast parts of machine transients, the resulting area decomposition is independent of fault locations. The procedure is illustrated by a 16-machine example.