Acoustic Vector-Corrected Impedance Meter

We describe the development of a novel instrument intended for the measurement of the acoustical reflection coefficient of materials. The instrument effectively implements a one-port vector-corrected network analyzer in the acoustic, rather than the electromagnetic, domain. Employing the well-documented methods of error correction familiar to microwave engineers, this instrument permits automated measurement of an acoustic impedance presented to a waveguide port. A dual-directional coupler allows a working frequency range of well over an octave. In principle, a set of six couplers would allow measurement from 100 to 50000 Hz

Determining acoustical directionality in an impedance tube using multiple fixed microphones

Acoustic impedance of a port or object is a valuable piece of knowledge describing how well sound is transmitted or reflected. The commonly used slotted-line method is labourious and time consuming, requiring manual movement to find the maxima and minima at each frequency. This paper outlines a technique to computationally determine the magnitude and phase of the constituent travelling waves from the standing plane sound wave measurements in an impedance tube. Measured magnitude and phase data from multiple fixed microphones carefully spaced along the length of the impedance tube is numerically fitted to incident and reflected wave models, which can then be used to calculate the complex acoustic impedance at each frequency of interest

Vehicle lead-acid battery state-of-charge meter

We describe a state-of-charge, or “residual-capacity” meter for lead-acid batteries that intelligently synthesizes coulometric and terminal-voltage methods in a new algorithm to provide reliable, continuous readout of remaining capacity. Novel electronic circuit design eliminates the need to install a shunt in the vehicle. The meter learns the characteristics of a battery to which it is attached, removing the need for setup, customisation, programming or calibration at time of installation or battery replacement. The meter can thus be installed by unqualified personnel. Initial measurements suggest the design to be robust and accurate

In a Gondola : Barcarolle

https://digitalcommons.library.umaine.edu/mmb-ps/1096/thumbnail.jp

Fourth Amendment Challenge to an Internal Revenue Code Section 7602 Summons: United States v. Sun First National Bank of Orlando, 510 F.2d 1107 (5th Cir. 1975)

In 1973, the Internal Revenue Service undertook an investigation of the consolidated income tax return of the First at Orlando. The IRS directed the audit of Sun First National, the lead bank, as part of this investigation. Sun was cooperative at first, providing free access to most of its files. Then the IRS decided to examine the common trust fund to determine Sun\u27s tax reporting performance concerning various trusts it managed. The bank refused to comply with the summons. The Fifth Circuit Court of Appeals ordered enforcement of the summons. The fourth amendment objection was disposed of in a conclusory manner. The court admitted that its opinion did not squarely address the issues raised because the facts in the record did not disclose arbitrariness. Despite the court\u27s avoidance of the fourth amendment issue, Sun is a correct application of present authorities on standing and intervention. However, this article will attempt to demonstrate that those authorities are unsound and unjustifiably preclude taxpayers and third parties from raising fourth amendment objections in cases like Sun, where the summoned parties possess an arguably protectable privacy right

Research and education in management of large- scale technical programs. Appendix A - Uses and misuses of computers in urban affairs. Appendix B - Build, a community development simulation game. Appendix C - Urban simulation and gaming, preliminary experience and perspectives. Appendix D - Public attitudes toward programs of large- scale technological change, some reflections and policy prescriptions Semiannual progress report

Research and education in management of large scale technical programs - computers in urban affair

To a Star : A I\u27Etoile

https://digitalcommons.library.umaine.edu/mmb-ps/1953/thumbnail.jp

Effects of contaminants of emerging concern on Megaselia scalaris (Lowe, Diptera: Phoridae) and its microbial community.

Drought, rising temperatures, and expanding human populations are increasing water demands. Many countries are extending potable water supplies by irrigating crops with wastewater. Unfortunately, wastewater contains biologically active, long-lived pharmaceuticals, even after treatment. Run-off from farms and wastewater treatment plant overflows contribute high concentrations of pharmaceuticals to the environment. This study assessed the effects of common pharmaceuticals on a cosmopolitan saprophagous insect, Megaselia scalaris (Diptera: Phoridae). Larvae were reared on artificial diets spiked with contaminants of emerging concern (CECs) at environmentally relevant concentrations. Female flies showed no oviposition preference for treated or untreated diets. Larvae exposed to caffeine in diets showed increased mortality, and larvae fed antibiotics and hormones showed signs of slowed development, especially in females. The normal sex ratio observed in M. scalaris from control diets was affected by exposure to caffeine and pharmaceutical mixture treatments. There was an overall effect of treatment on the flies' microbial communities; notably, caffeine fed insects displayed higher microbial variability. Eight bacterial families accounted for approximately 95% of the total microbes in diet and insects. Our results suggest that CECs at environmentally relevant concentrations can affect the biology and microbial communities of an insect of ecological and medical importance

Properties of scalar--isoscalar mesons from multichannel interaction analysis below 1800 MeV

Scalar-isoscalar mesons are studied using an unitary model in three channels: pi-pi, K-anti K and an effective 2pi-2pi. All the solutions, fitted to the pi-pi and K-anti K data, exhibit a wide f0(500), a narrow f0(980) and two relatively narrow resonances, lying on different sheets between 1300 MeV and 1500 MeV. These latter states are similar to the f0(1370) and f0(1500) seen in experiments at CERN. Branching ratios are compared with available data. We have started investigations of some crossing symmetry and chiral constraints imposed near the pi-pi threshold on the scalar-isoscalar, scalar-isotensor and P-wave pi-pi amplitudes.Comment: Talk given at XVth Particles and Nuclei Int. Conf. (PANIC99), Uppsala, Sweden, June 10-16, 1999; 4 pages, 3 figures, file espcrc1.sty include