Fluid pressure balanced seal

A seal which increases in effectiveness with increasing pressure is presented. The seal's functional capability throughout both static and dynamic operation makes it particularly useful for sealing ball valve ports. Other features of the seal include the ability to seal two opposed surfaces simultaneously, tolerance of small misalignments, tolerance of wide temperature ranges, ability to maintain positive sealing contact under conditions of internal or external pressurization, and ability to conform to slight irregularities in seal or surface contours

Pressure responsive seal handles static and dynamic loads

Ported ball valves are sealed under both static and dynamic load conditions by a line-pressure responsive double-acting seal. The top of the seal engages the ported ball at the outer circumferential edge of the seal upper end, and the bottom of the seal seats on a flat circular land with a continuous wall

Oil and fat absorbing polymers

A method is described for forming a solid network polymer having a minimal amount of crosslinking for use in absorbing fats and oils. The polymer remains solid at a swelling ratio in oil or fat of at least ten and provides an oil absorption greater than 900 weight percent

Polymers used to absorb fats and oils: A concept

One approach to problem of excessive oils and fats is to develop method by which oil is absorbed into solid mixture for elimination as solid waste. Materials proposed for these purposes are cross-linked (network) polymers that have high affinity for aliphatic substances, i. e., petroleum, animal, and vegetable oils

Photonic integrated circuits based on quantum well intermixing techniques

The passive sections of a monolithic device must have a wider bandgap than the active regions to reduce losses due to direct interband absorption. Such bandgap engineering is usually realized by complicated regrown butt-joint or selective-area growth techniques. We, however, have developed a simple, flexible and low-cost alternative technique – quantum well intermixing (QWI) – to increase the bandgap in selected areas of an integrated device post-growth. To verify the QWI process, we have fabricated the following demonstrators: a 40 GHz semiconductor mode-locked laser producing pulses as short as 490 fs; a 10 GHz passively mode-locked extended cavity laser integrated with surface-etched distributed Bragg reflector (DBR) which can be tuned in both wavelength and pulse repetition rate; four 10 GHz 1.55 μm AlGaInAs/InP mode-locked surfaced-etched DBR lasers integrated combiner, a semiconductor optical amplifier and modulator where the four channels can be operated separately or simultaneously; a CWDM source with 12 nm wavelength separation based on an AlGaInAs/InP integrated distributed feedback laser array; and a 1.55 μm DFB laser monolithically integrated with power amplifier array. In all these applications, QWI has the advantage of eliminating crystal regrowth and the associated stringent tolerance requirements that are required in traditional integration schemes

155-μm distributed feedback laser monolithically integrated with amplifier array

We present a laterally coupled 1.55-μm distributed feedback laser monolithically integrated with multistage multimode interferences and semiconductor optical amplifiers, using low-bias currents and providing an output power of ∼100  mW with a quasi-single spatial-mode far-field pattern and low divergence angle of 3.5° in the horizontal direction. The fabrication techniques are based on side-wall gratings and quantum-well intermixing and offer a simple, flexible, and low cost alternative to conventional methods

Lunar simulation model and optical studies for Lunar Orbiter system support

Lunar model which simulates topographic and photometric characteristics of lunar surfac

Geologic utility of improved orbital measurement capabilities in reference to non-renewable resources

Spectral and spatial characteristics necessary for future orbital remote sensing systems are defined. The conclusions are based on the past decade of experience in exploring for non-renewable resources with reference to data from ground, aircraft, and orbital systems. Two principle areas of investigation are used in the discussion: a structural interpretation in a basin area for hydrocarbon exploration, and a discrimination of altered areas in the Cuprite district in Nevada

Service of process in the United States under Insolvency Rule 12.12

Explains the procedure to be followed by a UK based liquidator wishing to serve insolvency proceedings on parties based in the US under the Insolvency Rules 1986 r.12.12. Discusses the rule's requirements for obtaining leave of the court for service outside the jurisdiction, the court's discretion to order the manner of service, including the approach of the Chancery Division in Re Busytoday Ltd, and the obligations imposed by the Hague Convention on the Service Abroad of Judicial and Extrajudicial Documents in Civil or Commercial Matters 1965. Evaluates the methods of service authorised by the Convention and details the main elements involved in service by the Central Authority route or by a local process server

The Effect of Milwaukee’s Parental Choice Program on Student Achievement in Milwaukee Public Schools

This paper examines evidence on the “systemic effects” of expanding school choice in Milwaukee, Wisconsin. Milwaukee is home to one of the nation’s largest and longest-running school choice programs. If there are systemic effects from expanding school choice we should be able to see them in Milwaukee. This paper also introduces a novel method for analyzing systemic effects. Taking full advantage of student-level data, we develop a new measure of those effects based on the extent of voucher options that each student has each year. The idea behind this measure is that school systems face greater competitive pressure to serve students well when students have more options to leave. This type of measure might be useful for future analyses of systemic effects. Using this new approach, we find that students fare better academically when they have more options from Milwaukee’s voucher program. The effects are modest in magnitude, but they are robust to multiple specifications of the model