Polarimeter provides transient response in nanosecond range

Conventional polarimeter with a Senarmont compensator improves transient response and eliminates manual manipulation. A sampled photomultiplier output is fed to a low pass filter, resulting in a signal representing the optical state existing at the instant of sampling. With this technique, an unknown transient-induced retardation can be measured

Focal plane array optical proximity sensor

An optical proximity sensor for optically detecting an object within a predetermined detection volume is described. More specifically, an optical proximity sensor is disclosed having an illuminator assembly including lens and a plurality of light-emitting diodes located at first predetermined positions along the focal plane of the illuminator lens. A detector assembly including a detector lens and a plurality of photodiodes located at second predetermined positions along the focal plane of the detector lens is also provided. The two lenses are spaced apart a predetermined distance in order to define a predetermined detection volume. Additionally, a combination of optical proximity sensors, according to the invention, is disclosed wherein the sensors can be used in conjunction with a vehicle to provide a safety system for warning an operator when an object is within a volume defined by the proximity sensor combination

Variable area exhaust nozzle

An exhaust nozzle for a gas turbine engine comprises a number of arcuate flaps pivotally connected to the trailing edge of a cylindrical casing which houses the engine. Seals disposed within the flaps are spring biased and extensible beyond the side edges of the flaps. The seals of adjacent flaps are maintained in sealing engagement with each other when the flaps are adjusted between positions defining minimum nozzle flow area and the cruise position. Extensible, spring biased seals are also disposed within the flaps adjacent to a supporting pylon to thereby engage the pylon in a sealing arrangement. The flaps are hinged to the casing at the central portion of the flaps' leading edges and are connected to actuators at opposed outer portions of the leading edges to thereby maximize the mechanical advantage in the actuation of the flaps

Polarimeter for transient measurement Patent

Automatic polarimeter capable of measuring transient birefringence changes in electro-optic material

Miniature servo accelerometer is force- balanced

Miniature servo accelerometer measures unusually small forces of torques. The pendulous mass of the accelerometer is suspended by fused quartz torsion fibers in an electromagnetically force- balanced environment. It is used in gravity surveys for exploring mineral deposits

Light-direction sensor based on birefringency

Optical system consisting of polarizer, analyzer, quarterwave retarder converts incident light beam to one which has an intensity related to the extent the incident beam is off axis

HIV/AIDS mitigation strategies and the State in sub-Saharan Africa – the missing link?

BACKGROUND: The HIV/AIDS pandemic in sub-Saharan Africa is widely recognised as a development disaster threatening poverty reduction, economic growth and not merely a health issue. Its mitigation includes the societal-wide adoption and implementation of specific health technologies, many of which depend on functional institutions and State. DISCUSSION: Donor and International Institutions' strategies to mitigate HIV/AIDS in sub-Saharan Africa are premised on a single optimal model of the State, one which focuses on the decentralised delivery of public goods alone (such as healthcare) – the service delivery state. The empirical evidence, though sparse, of "successful" and "unsuccessful" sub-Saharan Africa states' performance in mitigating HIV/AIDS does not support this model. Rather, the evidence suggests an alternative model that takes a country context specific approach – encompassing political power, institutional structures and the level of health technology needed. This model draws on the historical experience of East Asian countries' rapid development. SUMMARY: For international public health policies to be effective, they must consider a country tailored approach, one that advocates a coordinated strategy designed and led by the State with involvement of wider society specific to each country's particular history, culture, and level of development

Remedial training: Will CRM work for everyone

The subject of those pilots who seem unresponsive to Cockpit Resource Management (CRM) training is addressed. Attention is directed to the need and opportunity for remedial action. Emphasis is given to the requirement for new perspectives and additional training resources. It is also argued that, contrary to conventional training wisdom, such individuals do not represent a hard core which is beyond assistance. Some evidence is offered that such a new perspective will lend itself to a wider appreciation of certain specific training needs. The role of appropriately trained specialists is briefly outlined, and a selected bibliography is attached. The combined experiences of several Pilot Advisory Groups (PAG's) within IFALPA member association form the basis for this discussion. It does not purport to desribe the activities of any one PAG. While much of the activities of PAG's have no relevance to CRM, there are clearly some very important points of intersection. The relevance of these points to diagnostic skills, and remedial training in the general domain of CRM is made obvious

Method and data evaluation at NASA endocrine laboratory

The biomedical data of the astronauts on Skylab 3 were analyzed to evaluate the univariate statistical methods for comparing endocrine series experiments in relation to other medical experiments. It was found that an information storage and retrieval system was needed to facilitate statistical analyses