Effect of dietary and synthetic chelating agents on the intestinal absorption of lead

The effect of a number of dietary and synthetic chelating agents on the intestinal absorption of lead has been examined using the everted sac preparation and the tracer isotope ²⁰³Pb. All the agents examined increased lead transport into the serosal compartment. An explanation of the way in which these agents modify the model to describe lead transport is proposed.     

Circular arrays of radial and tangential dipoles for turnstile antennas

A method of obtaining a turnstile antenna from a circular array of radial or tangential dipoles is presented. Approximate current distributions, terminal admittances, and radiation fields are given for arrays of 3, 4, and 5 half-wavelength elements for various array diameters.     

Teaching teamwork

Few computer science programs offer the software engineering training developers need. Team-based courses are essential to this training and can be structured in various ways. The authors discuss the benefits of using the Introductory Team Software Process in a computing curriculum and discuss its role in preparing students to work as industrial software engineers.     

A Microcomputer-Based Supervisory System for a Mercury-Cell Chlorine Plant

The hardware and software structure of a microcomputer-based supervisory system for a mercury-cell chlorine plant. The system monitors data for 52 chlorine cells and provides control of each cell for specified low and high set points which are functions of currents and voltages. The microcomputer consists of an 8080A microprocessor using 14 K of PROM and 17 K of RAM. The software is designed for a seven-level priority interrupt structure. The system stores 13 kbytes of data and generates a complete record of production totals and individual cell performance.     

C₆₀ oxide as a key component of aqueous C₆₀ colloidal suspensions

Stable aqueous fullerene colloidal suspensions (nC(60)) are demonstrated to rely on the [6,6]-closed epoxide derivative of the fullerene (C(60)O) for stability. This derivative is present, though often unrecognized, in small quantities in nearly all C(60) starting materials due to a reaction with air. The low-yield formation of nC(60) from organic solvent solutions results from a preferential partitioning and thus enrichment of C(60)O in the colloidal particles. This partitioning is significantly retarded in the nC(60) synthesis method that does not involve organic solvent solutions: long-term stirring in water. Instead, this method relies on trace levels of ozone in the ambient atmosphere to produce sufficient C(60)O at the surfaces of the nC(60) particles to allow stable suspension in water. Controlled-atmosphere syntheses, deliberate C(60)O enrichment, light scattering measurements, and extraction followed by HPLC analysis and UV-visible absorption spectroscopy support the above model of nC(60) formation and stabilization.     

The visual and driving performance of monocular and binocular heavy-duty truck drivers

This study compared the performance of 40 monocular and 40 binocular tractor-trailer drivers on measures of both visual and driving performance. On the visual measures, the mononuclear drivers were significantly deficient in contrast sensitivity, visual acuity under low illumination and glare, and binocular depth perception. They were not significantly deficient in static or dynamic visual acuity, visual field of individual eyes, or glare recovery. Driving measures of visual search, lane keeping, clearance judgment, gap judgment, hazard detection, and information recognition showed no differences between monocular and binocular drivers. Monocular drives were poorer than binocular drivers only in sign reading distance in both daytime and nighttime driving. This decrement correlated significantly with the binocular depth perception measure. There were large individual differences within each group for most of the visual and driving performance measures. It was concluded that monocular drivers have some significant reductions in selected visual capabilities and in certain driving functions dependent on these abilities, compared with binocular drivers. However, monocular drivers are not significantly worse than binocular drivers in the safety of most day-to-day driving functions. Implications of these findings and the large individual differences within each group are discussed.     

K band frequency-scanned waveguide array

This paper presents the design of aKband frequency scanned array in an RG 96/U waveguide. The radiating elements consist of slots machined in the narrow wall of the guide. experiment-resluts of the measured slot conductances for the antenna elements and the feed system are given for slot spacings of 0.25 inches and various slot orientations and depths. Theoretical optimum efficiencies for uniform, Chebyshev, and Taylor distributions are also presented. Finally, the experimental results for a 400-element planar array are given.     

SE2004: Recommendations for Undergraduate Software Engineering Curricula

Universities throughout the world have established undergraduate programs in software engineering, which complement existing programs in computer science and computer engineering. To provide guidance in designing an effective curriculum, the IEEE Computer Society and the ACM have developed the Software Engineering 2004 (SE2004) set of recommendations. The SE2004 document guides universities and colleges regarding the knowledge they should teach in undergraduate software engineering programs. It also provides sample courses and curriculum patterns. SE2004 begins with an overview of software engineering, explaining how it is both a computing and an engineering discipline. It then outlines the principles that drove the document's development and describes expected student outcomes. Next, SE2004 details the knowledge that universities and colleges should teach, known as SEEK (software engineering education knowledge), in a software engineering program. These recommendations are followed by general pedagogical guidelines, sample courses, and sample curriculum patterns     

具有Ni-Cr结合涂覆层无粘结剂的铜——聚酰亚胺基板

聚酰亚胺基板上的无粘结剂的铜将普遍应用于精细导线和高密度电子互连的领域。医疗、硬盘驱动和COF(chip on flex)应用上往往要求线宽/间距(L/S)为50μm(2mil)或更精细。无粘结剂材料将有利