Arrays of large-area, tip/tilt micromirrors for use in a high-contrast projector

Arrays of two-degree of freedom analog micromirrors are designed for use within an high-contrast projector and fabricated using a multi-user MEMS fabrication process. We demonstrate a novel way of optimizing the tradeoffs between tilt angle and mirror size by subdividing the mirrors into smaller functional subsections that move synchronously. The mirror design employs multiple mirrors within a gimbal frame. The frame rotates around one axis, and each mirror within the frame rotates around a perpendicular axis, resulting in two-degree of freedom rotation. The design employs specific electrode shapes to allow one-layer connections. Using these fabricated mirrors, simultaneous actuation of mirrors within a composite structure is achieved. A prototype array of fabricated mirrors is described, with 6 × 5 mirrors each of 160 μm × 160 μm forming one composite mirror of an array, giving total active area of 960 μm × 800 μm. The mirrors can achieve a maximum tilt angle of 2.25°. The fill factor of this design is 68%.     

32—STUDIES ON TEXTILE INSECTPROOFING. PART III: ORGANOPHOSPHORUS INSECTICIDES

An investigation is described in which Chlorpyrifos (O,O-diethyl-O-3,5, 6-trichloropyridyl-phosphorothioate) was found to be the most active of eleven organophosphorus insecticides evaluated as mothproofing agents. Its minimum effective concentration on wool was approximately 0.005%(w/w). Bioassay indicated that application of 0.05% of Chlorpyrifos (at 6O–80°C) conferred mothproofness that survived laundering and dry-cleaning. Chemical-residue analysis revealed large losses of this steam-volatile insecticide during fabric treatment, storage, and use that make it unsuitable for permanent mothproofing applications.     

Modeling Spatial-Temporal Data with a Short Observation History

A novel method is proposed for forecasting spatial-temporal data with a short observation history sampled on a uniform grid. The method is based on spatial-temporal autoregressive modeling where the predictions of the response at the subsequent temporal layer are obtained using the response values from a recent history in a spatial neighborhood of each sampling point. Several modeling aspects such as covariance structure and sampling, as well as identification, model estimation and forecasting issues, are discussed. Extensive experimental evaluation is performed on synthetic and real-life data. The proposed forecasting models were shown capable of providing a near optimal prediction accuracy on simulated stationary spatial-temporal data in the presence of additive noise and a correlated model error. Results on a spatial-temporal agricultural dataset indicate that the proposed methods can provide useful prediction on complex real-life data with a short observation history.     

Simulations of Phase Slippage in an Aperture Array

To understand the origins of synchronous and asynchronous phase slippages observed in an array of apertures connecting two reservoirs of superfluid ⁴He, we have investigated the role of thermal fluctuations in the critical velocity and the possible effects of having an array rather than a single aperture through several model simulations. The results are compared with recent experiments carried out near the superfluid transition temperature with an array of apertures as well as those carried out at low temperatures with a single aperture.     

Use of Doppler ultrasonography and positive-contrast corpus cavernosography to evaluate a persistent penile hematoma in a bull

A 32-month-old Angus bull was evaluated because of a 2-month history of a slowly progressive swelling located cranial to the base of the scrotum. The mass was 8 x 8 x 6 cm, and was causing phimosis. The mass was determined to be a penile hematoma on the basis of results of ultrasonography and exploratory surgery. Surgical evacuation was not performed initially because the deep fascia of the penis was intact and the hematoma was small; however, the hematoma enlarged slowly during the ensuring 2 months, despite sexual rest and isolation from other livestock. Doppler ultrasonography and positive-contrast corpus cavernosography were performed, and the hematoma was seen as a space-occupying mass within the corpus cavernosum penis; vascular anomalies were not found. The penile hematoma was surgically excised, and the bull was isolated for 60 days. At follow-up, the owner indicated that the bull had returned to pasture-breeding soundness and was still being used 2 years after surgery. The small penile hematoma in this bull was unusual in that it did not respond to medical treatment. Surgical treatment was apparently curative, even though surgery was not performed until 4 months after the hematoma was first detected.     

In Situ Formation of Dendrites in Eumelanin Thin Films between Gold Electrodes

Eumelanin is a ubiquitous pigment in the human body, animals, and plants, with potential for bioelectronic applications because of its unique set of physical and chemical properties, including strong UV‐vis absorption, mixed ionic/electronic conduction, free radical scavenging and anti‐oxidant properties. Herein, a detailed investigation is reported of eumelanin thin films grown on substrates patterned with gold electrodes as a model system for device integration, using electrical measurements, atomic force microscopy, scanning electron microscopy, fluorescence microscopy, and time‐of‐flight secondary ion mass spectroscopy. Under prolonged electrical biasing in humid air, one can observe gold dissolution and formation of gold‐eumelanin nanoaggregates, the assembly of which leads to the formation of dendrites forming conductive pathways between the electrodes. Based on results collected with eumelanins from different sources, a mechanism is proposed for the formation of the nanoaggregates and dendrites, taking into account the metal binding properties of eumelanin. The surprising interaction between eumelanin and gold points to new opportunities for the fabrication of eumelanin‐gold nanostructures and biocompatible memory devices and should be taken into account in the design of devices based on eumelanin thin films.     

11—STUDIES ON TEXTILE INSECTPROOFING. PART II: SUBSTITUTED PHENYLTHIOUREAS,INCLUDING FIBRE-REACTIVE DERIVATIVES

An account is given of a study of a series of substituted phenylthioureas, prepared and examined as feeding inhibitors for clothes-moth and carpet-beetle larvae. Some of these compounds were fibre-reactive. Bioassay indicated that bisulphite-assisted applications of N-phenyl-N'-vinylsulphonylpropionylthiourea (1% w/w) were fast on wool during laundering and dry-cleaning. With the exception of N-phenyl-N'-(benzothiazol-2-yl)thiourea, the moth-active compounds were poor inhitors of carpet-beetle feeding.