Low-Power Architecture for an Optical Life Gas Analyzer

Analog and digital electronic control architecture has been combined with an operating methodology for an optical trace gas sensor platform that allows very low power consumption while providing four independent gas measurements in essentially real time, as well as a user interface and digital data storage and output. The implemented design eliminates the cross-talk between the measurement channels while maximizing the sensitivity, selectivity, and dynamic range for each measured gas. The combination provides for battery operation on a simple camcorder battery for as long as eight hours. The custom, compact, rugged, self-contained design specifically targets applications of optical major constituent and trace gas detection for multiple gases using multiple lasers and photodetectors in an integrated package

In Situ Aerosol Detector

An affordable technology designed to facilitate extensive global atmospheric aerosol measurements has been developed. This lightweight instrument is compatible with newly developed platforms such as tethered balloons, blimps, kites, and even disposable instruments such as dropsondes. This technology is based on detection of light scattered by aerosol particles where an optical layout is used to enhance the performance of the laboratory prototype instrument, which allows detection of smaller aerosol particles and improves the accuracy of aerosol particle size measurement. It has been determined that using focused illumination geometry without any apertures is advantageous over using the originally proposed collimated beam/slit geometry (that is supposed to produce uniform illumination over the beam cross-section). The illumination source is used more efficiently, which allows detection of smaller aerosol particles. Second, the obtained integral scattered light intensity measured for the particle can be corrected for the beam intensity profile inhomogeneity based on the measured beam intensity profile and measured particle location. The particle location (coordinates) in the illuminated sample volume is determined based on the information contained in the image frame. The procedure considerably improves the accuracy of determination of the aerosol particle size

Two approaches to reversing language shift and the Soviet publication program for indigenous minorities

The present paper discusses the interplay between the Soviet state policy towards indigenous languages of "Northern Minorities" and the attitudes of the indigenous communities to their languages and to language endangerment. The author uses statistics on the Soviet state program of publishing books (primarily school books) in indigenous languages that was launched in the late 1920s and underwent considerable changes in the course of the decades to follow. It is argued that the publishing policy for all languages of indigenous minorities of the Far North followed the same consistent pattern that included several phases: "a glorious beginning" in the 1930s interrupted by the war, then a strong continuation in the 1950s, then a drop in the 1960-70s, and a resurrection in the 1980s, interrupted by the economic crisis of the early 1990s. The most interesting and the least clear period is the two and a half decades between mid-1950s and late 1970s where changes of the state policy may be connected with changes in community attitudes towards their native languages. A successful policy of language preservation and revitalization is possible only if it is supported simultaneously by the state and the indigenous community.L'article discute de l'interaction entre la politique soviétique officielle concernant les langues indigènes des «minorités du Nord» et les attitudes de ces communautés envers leurs propres langues et envers leur mise en danger. L'auteur exploite les statistiques du programme soviétique étatique de publication d'ouvrages en langues indigènes (essentiellement des manuels pour l'école primaire), lancé par l'État dans les années 1920, et qui subit des modifications considérables au cours des décennies suivantes. La thèse développée est que les programmes de publication pour les langues minoritaires du Grand Nord ont tous obéi à peu près au même schéma et ont connu les phases suivantes: un début flamboyant dans les années 1930, interrompu par la guerre, puis une reprise vigoureuse dans les années 1950, ainsi qu’un abandon dans les années 1960-70, suivi d'une résurrection dans les années 1980, à son tour interrompue par la crise économique du début des années 1990. La plus intéressante, et la moins claire des phases étudiées est celle de la reprise qui va du milieu des années 1950 jusqu'à la fin des années 1970. Les changements intervenus dans la politique de l'État peuvent être mis en rapport avec ceux dans l'attitude des communautés vis-à-vis de leurs propres langues natales. Une politique de préservation et de revitalisation de la langue ne saurait avoir de succès que si elle est soutenue tant par les communautés indigènes que par l'État

Digital Architecture for a Trace Gas Sensor Platform

A digital architecture has been implemented for a trace gas sensor platform, as a companion to standard analog control electronics, which accommodates optical absorption whose fractional absorbance equivalent would result in excess error if assumed to be linear. In cases where the absorption (1-transmission) is not equivalent to the fractional absorbance within a few percent error, it is necessary to accommodate the actual measured absorption while reporting the measured concentration of a target analyte with reasonable accuracy. This requires incorporation of programmable intelligence into the sensor platform so that flexible interpretation of the acquired data may be accomplished. Several different digital component architectures were tested and implemented. Commercial off-the-shelf digital electronics including data acquisition cards (DAQs), complex programmable logic devices (CPLDs), field-programmable gate arrays (FPGAs), and microcontrollers have been used to achieve the desired outcome. The most completely integrated architecture achieved during the project used the CPLD along with a microcontroller. The CPLD provides the initial digital demodulation of the raw sensor signal, and then communicates over a parallel communications interface with a microcontroller. The microcontroller analyzes the digital signal from the CPLD, and applies a non-linear correction obtained through extensive data analysis at the various relevant EVA operating pressures. The microcontroller then presents the quantitatively accurate carbon dioxide partial pressure regardless of optical density. This technique could extend the linear dynamic range of typical absorption spectrometers, particularly those whose low end noise equivalent absorbance is below one-part-in-100,000. In the EVA application, it allows introduction of a path-length-enhancing architecture whose optical interference effects are well understood and quantified without sacrificing the dynamic range that allows quantitative detection at the higher carbon dioxide partial pressures. The digital components are compact and allow reasonably complete integration with separately developed analog control electronics without sacrificing size, mass, or power draw

Optical Multi-Gas Monitor Technology Demonstration on the International Space Station

The International Space Station (ISS) employs a suite of portable and permanently located gas monitors to insure crew health and safety. These sensors are tasked with functions ranging from fixed mass spectrometer based major constituents analysis to portable electrochemical sensor based combustion product monitoring. An all optical multigas sensor is being developed that can provide the specificity of a mass spectrometer with the portability of an electrochemical cell. The technology, developed under the Small Business Innovation Research program, allows for an architecture that is rugged, compact and low power. A four gas version called the Multi-Gas Monitor was launched to ISS in November 2013 aboard Soyuz and activated in February 2014. The portable instrument is comprised of a major constituents analyzer (water vapor, carbon dioxide, oxygen) and high dynamic range real-time ammonia sensor. All species are sensed inside the same enhanced path length optical cell with a separate vertical cavity surface emitting laser (VCSEL) targeted at each species. The prototype is controlled digitally with a field-programmable gate array/microcontroller architecture. The optical and electronic approaches are designed for scalability and future versions could add three important acid gases and carbon monoxide combustion product gases to the four species already sensed. Results obtained to date from the technology demonstration on ISS are presented and discussed

Optical Breath Gas Sensor for Extravehicular Activity Application

The function of the infrared gas transducer used during extravehicular activity (EVA) in the current space suit is to measure and report the concentration of carbon dioxide (CO2) in the ventilation loop. The next generation Portable Life Support System (PLSS) requires next generation CO2 sensing technology with performance beyond that presently in use on the Shuttle/International Space Station extravehicular mobility unit (EMU). Accommodation within space suits demands that optical sensors meet stringent size, weight, and power requirements. A laser diode (LD) spectrometer based on wavelength modulation spectroscopy (WMS) is being developed for this purpose by Vista Photonics, Inc. Two prototype devices were delivered to NASA Johnson Space Center (JSC) in September 2011. The sensors incorporate a laser diode based CO2 channel that also includes an incidental water vapor (humidity) measurement and a separate oxygen (O2) channel using a vertical cavity surface emitting laser (VCSEL). Both prototypes are controlled digitally with a field-programmable gate array (FPGA)/microcontroller architecture. Based on the results of the initial instrument development, further prototype development and testing of instruments leveraging the lessons learned were desired. The present development extends and upgrades the earlier hardware to the Advanced PLSS 2.0 test article being constructed and tested at JSC. Various improvements to the electronics and gas sampling are being advanced by this project. The combination of low power electronics with the performance of a long wavelength laser spectrometer enables multi-gas sensors with significantly increased performance over that presently offered in the EMU.

The Concept of Work in Yupik Eskimo Society Before and After the Russian Influx: A Linguist’s Perspective

The Yupik language has a word to signify ‘work’ derived from the stem qepgha(gh)- (qepghaq ‘work’ [noun], qepghaghtuq ‘he works’, qepghaghta ‘worker’, etc.) The scope of the meaning of this word changed drastically after the Russians came to Chukotka to stay in the 1930s. While in the pre-(intensive) contact times the word mainly meant ‘house work’ or ‘processing the carcass of a killed animal’, in mid-20th century it acquired new meanings, borrowing them from Russian. The usage of the word also became a replica of Russian usage: the concept acquired new dependent words, like evaluative adverbs and adjectives, or inanimate agents. This change of meaning reflected social changes that took place in the Yupik world as a result of the modernisation process of the 1950s and 1960s, and is an indicator of the deep transformation the society underwent under Russian (Soviet) influence. The paper analyses this process using two sources from two different epochs: Yupik texts recorded by Yekaterina Rubtsova in the 1940s, that is, in the pre-(intensive) contact period, and a modern Russian-Yupik dictionary compiled by Natalia Rodionova, a teacher of Yupik Eskimo at the Anadyr college, and published 70 years later, in 2014.&nbsp

Optical Breath Gas Sensor for Extravehicular Activity Application

The function of the infrared gas transducer used during extravehicular activity in the current space suit is to measure and report the concentration of carbon dioxide (CO2) in the ventilation loop. The next generation portable life support system (PLSS) requires next generation CO2 sensing technology with performance beyond that presently in use on the Space Shuttle/International Space Station extravehicular mobility unit (EMU). Accommodation within space suits demands that optical sensors meet stringent size, weight, and power requirements. A laser diode spectrometer based on wavelength modulation spectroscopy is being developed for this purpose by Vista Photonics, Inc. Two prototype devices were delivered to NASA Johnson Space Center (JSC) in September 2011. The sensors incorporate a laser diode-based CO2 channel that also includes an incidental water vapor (humidity) measurement and a separate oxygen channel using a vertical cavity surface emitting laser. Both prototypes are controlled digitally with a field-programmable gate array/microcontroller architecture. The present development extends and upgrades the earlier hardware to the Advanced PLSS 2.0 test article being constructed and tested at JSC. Various improvements to the electronics and gas sampling are being advanced by this project. The combination of low power electronics with the performance of a long wavelength laser spectrometer enables multi-gas sensors with significantly increased performance over that presently offered in the EMU