Apparatus for detecting the amount of material in a resonant cavity container Patent

Quantitative liquid measurements in container by resonant frequencie

The Angular Momenta of Neutron Stars and Black Holes as a Window on Supernovae

It is now clear that a subset of supernovae display evidence for jets and are observed as gamma-ray bursts. The angular momentum distribution of massive stellar endpoints provides a rare means of constraining the nature of the central engine in core-collapse explosions. Unlike supermassive black holes, the spin of stellar-mass black holes in X-ray binary systems is little affected by accretion, and accurately reflects the spin set at birth. A modest number of stellar-mass black hole angular momenta have now been measured using two independent X-ray spectroscopic techniques. In contrast, rotation-powered pulsars spin-down over time, via magnetic braking, but a modest number of natal spin periods have now been estimated. For both canonical and extreme neutron star parameters, statistical tests strongly suggest that the angular momentum distributions of black holes and neutron stars are markedly different. Within the context of prevalent models for core-collapse supernovae, the angular momentum distributions are consistent with black holes typically being produced in GRB-like supernovae with jets, and with neutron stars typically being produced in supernovae with too little angular momentum to produce jets via magnetohydrodynamic processes. It is possible that neutron stars are imbued with high spin initially, and rapidly spun-down shortly after the supernova event, but the available mechanisms may be inconsistent with some observed pulsar properties.Comment: ApJ Letters, accepte

Determination of Fares: Pricing Theory and Economic Efficiency

The concept of economic efficiency is described, its application to the pricing of air transport services, and its relevance as a policy objective are outlined. The first two sections discuss economic efficiency in general terms, whereas the third applies this norm to several airline pricing problems. The final section emphasizes the importance of industry behavior as a parameter in policy analysis

Physical environment, nutrient budget, and ecology of Lake Moana-nui, Tokoroa

This report is based on fortnightly monitoring data collected over a 14 month period from November 2000 to January 2002 and a survey of the lake bathymetry and vegetation distribution. The project also included a detailed investigation into the associations between macroinvertebrates and the native and exotic plants in the lake, and experiments evaluating the effects of the large populations of the water flea Simocephalus vetulus that the lake maintains on algal concentrations and therefore water clarity. The aim of this report is to present and discuss the results of the monitoring, surveys, and experiments in order to make recommendations for the future management and health of Lake Moana-nui

Secondary reflectors for economical sun-tracking energy collection system: A concept

Mechanism is simpler and lower in cost because it moves heat-collector pipe to stay in focus with sun, instead of moving heavy reflectors

A two-degree Kelvin refrigerator

Open-cycle cryogenic refrigerator maintains temperature as low as 2K for periods up to six months. Designed to cool an infrared detector, refrigerator can be used in cooling Josephson-junction devices, magnetic bubble domains, and superconducting devices

Low-cost solar tracking system

Smaller heat-collector is moved to stay in focus with the sun, instead of moving reflector. Tracking can be controlled by storing data of predicted solar positions or by applying conventional sun-sensing devices to follow solar movement

Underground mineral extraction

A method was developed for extracting underground minerals such as coal, which avoids the need for sending personnel underground and which enables the mining of steeply pitched seams of the mineral. The method includes the use of a narrow vehicle which moves underground along the mineral seam and which is connected by pipes or hoses to water pumps at the surface of the Earth. The vehicle hydraulically drills pilot holes during its entrances into the seam, and then directs sideward jets at the seam during its withdrawal from each pilot hole to comminute the mineral surrounding the pilot hole and combine it with water into a slurry, so that the slurried mineral can flow to a location where a pump raises the slurry to the surface

Chemotactic Turning Behaviour of Tubularia Spermatozoa

1. The movements of Tubularia spermatozoa in the vicinity of micropipettes filled with extracts of female hydranths, which chemotactically attract the spermatozoa, have been recorded by multiple-flash photomicrography. 2. When a spermatozoon turns in response to a chemotactic stimulus, the flagellum continues to beat, with a highly asymmetrical pattern of bending, during the turn. 3. The magnitude of the turn, particularly the duration of the period of asymmetrical beating, is variable, but each spermatozoon is only able to make turns in one direction, relative to its own body. 4. Most of the behaviour of these spermatozoa may be explained if the turning mechanism is activated when the spermatozoon detects a decreasing concentration of the chemotactant