Computer Determination of Electromagnetic Wave Shielding Effectiveness

The author has developed a technique for rapid determination of the shielding effectiveness of any metal through use of the IBM remote access computing system (RAX). RAX consists of one central computer and numerous control terminals placed throughout Bell Aerosystems engineering areas. To obtain a matrix of shielding information versus frequency the engineer activates his terminal, inserts his program from the library file, and supplies the desired metal thickness, conductivity, permeability, and test distance. The terminal then prints a table of shielding effectiveness. The entire process can be accomplished in about four minutes. This paper includes several samples of output data, lists the program which was used, and shows how the engineer communicates with the machine to obtain the desired output.     

Direct Graphical Determination of Optimum Shielding and Suppression

Signal parameters which will result in satisfactory levels of interference can be obtained directly from the graphs included in this paper. These graphs may be used to determine permissible waveforms for pulses, step functions, and CW signals for compliance with broad-band radiated, narrow-band radiated, and conducted interference limits. Curves are included for MIL-I-26600, MIL-I-6181D, MIL-I-11748, and MIL-STD-826. The curves are extremely simple for designers to use in determining shielding and suppression requirements. They may also be incorporated into the interference control plan to indicate to the customer that adequate interference control techniques will be incorporated.     

Simulation package for small-scale systems

A simulation package for microcomputers has been developed which is applicable to small- and medium-size problems in the educational and industrial environment. The package consists of: an ordinary differential equations simulator capable of solving up to 12 simultaneous first-order ordinary differential equations; a simultaneous linear and nonlinear equations solver capable of solving systems containing up to 12 linear and nonlinear equations; an extended polynomial/nonlinear curve fitting program capable of fitting a variety of equations to a set of data points of Y_i versus X_i; and an extended multiple-linear-regression program which can fit mathematical models containing up to five linear parameters to experimental data.The paper describes this simulation package, demonstrates some typical applications, and summarizes recent experience in using the package in an educational environment.     

Regulation of mitochondrial iron accumulation by Yfh1p, a putative homolog of frataxin

The gene responsible for Friedreich's ataxia, a disease characterized by neurodegeneration and cardiomyopathy, has recently been cloned and its product designated frataxin. A gene in Saccharomyces cerevisiae was characterized whose predicted protein product has high sequence similarity to the human frataxin protein. The yeast gene (yeast frataxin homolog, YFH1) encodes a mitochondrial protein involved in iron homeostasis and respiratory function. Human frataxin also was shown to be a mitochondrial protein. Characterizing the mechanism by which YFH1 regulates iron homeostasis in yeast may help to define the pathologic process leading to cell damage in Friedreich's ataxia.     

Effects of Cry1F and Cry34Ab1/35Ab1 on storage pests

Two crystalline protoxins from Bacillus thuringiensis (Bt), Cry1Fa1 and Cry34Ab1/Cry35Ab1 (Cry1F, Cry34/35Ab1), were evaluated for efficacy against lepidopteran and coleopteran storage pests. Cry1F was tested against the lepidopterans Sitotroga cerealella (Angoumois grain moth) and colonies of Plodia interpunctella (Indian mealmoth) that are susceptible or resistant to Bt Cry1Ab and Cry1Ac toxins, Bt subspecies entomocidus, and the commercial formulation Dipel^®. Cry1F was also tested against the coleopterans Cryptolestes pusillus (flat grain beetle) and Tribolium castaneum (red flour beetle). Cry34/35Ab1 was tested against S. cerealella, C. pusillus, and T. castaneum, and against additional coleopteran storage pests, including Tenebrio molitor (yellow mealworm), Trogoderma variabile (warehouse beetle), Oryzaephilus surinamensis (sawtoothed grain beetle), Rhyzopertha dominica (lesser grain borer), and Sitophilus oryzae (rice weevil). Strains of Bt-susceptible or -resistant P. interpunctella generally were more sensitive to Cry1A protoxin or toxin than either Cry1F protoxin or Dipel. Despite difficulties with the bioassay of S. cerealella larvae, the data suggest that Cry1F and Cry34/35Ab1 caused increased larval mortality, and a developmental delay was observed and no pupae emerged with 0.9% Cry1F. Neither Cry1F nor the corn rootworm-active toxin Cry34/35Ab1 significantly affected the biological parameters of the coleopteran species evaluated.     

Evaluation of a System for Residential Treatment and Reuse of Wastewater

Approximately one-quarter of housing units in the United States are not connected to centralized, publicly owned wastewater treatment works and instead operate their own cesspools or septic tanks that provide only partial treatment. A study was conducted in which a commercially available, on-site, residential wastewater package unit was tested at its design capacity according to an established protocol to determine if it could produce a high-quality effluent. Additional pilot-scale sand filtration and ultraviolet disinfection units were fabricated and operated to determine the feasibility of producing recycled water suitable for residential reuse and which could meet strict water reuse regulations. The results indicate that the package unit can produce an effluent equivalent to secondary effluent when properly operated and maintained. In addition, using add-on sand filter and ultraviolet light disinfection units, it was possible to produce the highest quality of reclaimed water recognized by Hawaii regulations (oxidized, filtered, disinfected, unrestricted use). It was also possible and may be economically feasible to produce a slightly lower quality reclaimed water (oxidized, disinfected, R-2) suitable for residential subsurface irrigation.     

Polarized 3He Spin Filters for Slow Neutron Physics

Polarized ³He spin filters are needed for a variety of experiments with slow neutrons. Their demonstrated utility for highly accurate determination of neutron polarization are critical to the next generation of betadecay correlation coefficient measurements. In addition, they are broadband devices that can polarize large area and high divergence neutron beams with little gamma-ray background, and allow for an additional spin-flip for systematic tests. These attributes are relevant to all neutron sources, but are particularly well-matched to time of flight analysis at spallation sources. There are several issues in the practical use of ³He spin filters for slow neutron physics. Besides the essential goal of maximizing the ³He polarization, we also seek to decrease the constraints on cell lifetimes and magnetic field homogeneity. In addition, cells with highly uniform gas thickness are required to produce the spatially uniform neutron polarization needed for beta-decay correlation coefficient experiments. We are currently employing spin-exchange (SE) and metastability-exchange (ME) optical pumping to polarize ³He, but will focus on SE. We will discuss the recent demonstration of 75 % ³He polarization, temperature-dependent relaxation mechanism of unknown origin, cell development, spectrally narrowed lasers, and hybrid spin-exchange optical pumping.     

The relationship between treatment, incarceration, and recidivism of battering: A program evaluation of Seattle's coordinated community response to domestic violence.

Men who batter (N?=?387) were followed over 2 years using a quasi-experimental design. "Batterers" were court-mandated into domestic violence (DV) group treatment, DV treatment plus chemical dependency treatment, or were incarcerated in lieu of treatment. Official criminal records of treatment completers, treatment noncompleters, and incarcerated batters were compared 2 years after sentencing. Batterers who completed DV group treatment had fewer DV reoffenses at follow-up, and incarcerated batterers had a greater number, as compared with DV treatment noncompleters, after controlling for criminal record and demographics. The number of DV sessions attended was negatively correlated with recidivism. This study provides suggestive evidence that the coordinated domestic violence intervention may have a statistically significant but small impact on reducing domestic violence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analog characteristics of metal-insulator-metal capacitors usingPECVD nitride dielectrics

The frequency dependence of PECVD nitride and LPCVD oxide metal-insulator-metal (MIM) capacitors is investigated with special attention for precision analog applications. At measurement frequencies of 1.0 MHz, nitride MIM capacitors show capacitance linearity close to that of oxide MIM capacitors, indicating potential for precision analog circuit applications. Due to dispersion effects, however, nitride MIM capacitors show significant degradation in capacitor linearity as the frequency is reduced, which leads to accuracy limitations for precision analog circuits. Oxide MIM capacitors are essentially independent of frequency