Psychophysical Research in Development of a Fiber-optic Helmet Mounted Display

The Fiber Optic Helmet Mounted Display (FOHMD) was conceived as an innovative solution to existing flight simulator display deficiencies. An initial (breadboard) version of the system was fabricated to permit experimentation which would help define design requirements for a more refined engineering prototype. A series of visual/human factors studies are being conducted at the USAF Human Resources Laboratory (AFHRL) Operations Training Division, Williams AFB, Arizona to determine the optimum fit of human observer operating characteristics and fiber optic helmet mounted display technology. Pilot performance within a variety of high resolution insert/binocular overlap combinations is being assessed in two classes of environment. The first two of four studies planned incorporate an air-to-air combat environment, whereas the second two studies will use a low level environment with air to ground weapons delivery

HUT observations of carbon monoxide in the coma of Comet Levy (1990c)

Observations of comet Levy (1990c) were made with the Hopkins Ultraviolet Telescope during the Astro-1 Space Shuttle mission on 10 Dec. 1990. The spectrum, covering the wavelength range 415 to 1850 A at a spectral emission of 3 A (in first order), shows the presence of carbon monoxide and atomic hydrogen, carbon, and sulfur in the coma. Aside from H I Lyman-beta, no cometary features are detected below 1200 A, although cometary O I and O II would be masked by the same emissions present in the day airglow spectrum. The 9.4 x 116 arcsec aperture corresponds to 12,000 x 148,000 km at the comet. The derived production rate of CO relative to water, 0.13 + or - 0.02, compared with the same ratio derived from IUE observations (made in Sep. 1990) which sample a much smaller region of the coma, 0.04 + or - 0.01, suggests the presence of an extended source of CO, as was found in comet Halley. Upper limits on Ne and Ar abundance are within an order of magnitude or solar abundances

CalFUSE v3: A Data-Reduction Pipeline for the Far Ultraviolet Spectroscopic Explorer

Since its launch in 1999, the Far Ultraviolet Spectroscopic Explorer (FUSE) has made over 4600 observations of some 2500 individual targets. The data are reduced by the Principal Investigator team at the Johns Hopkins University and archived at the Multimission Archive at Space Telescope (MAST). The data-reduction software package, called CalFUSE, has evolved considerably over the lifetime of the mission. The entire FUSE data set has recently been reprocessed with CalFUSE v3.2, the latest version of this software. This paper describes CalFUSE v3.2, the instrument calibrations upon which it is based, and the format of the resulting calibrated data files.Comment: To appear in PASP; 29 pages, 13 figures, uses aastex, emulateap

Research of stability of disc knives while cutting the elastomers

Приведено конструкцію пристрою до заточувального верстата для заточування дискових ножів, ножових блоків для розрізування еластомерів конвеєрних стрічок заданих розмірів. У результаті експериментальних досліджень встановлено межу працездатності ножів у часовому просторі й режими різання та заточування ножів.The construction of device of the grinding machine for sharpening unit disk blades for cutting elastomers conveyer belts of given size was shown. Industry of Germany exports rubber-cotton conveyer belt in roll of 0,9…2 m width and 50 m length to Ukraine. Special devices with the knives units and possibility of change their location due to the required belt width are used for cutting rolls into strips of the given width. Special devices for simultaneous grinding of two cutting blades was designed and produced with U-type bracket with the possibility of a circular rotation around the vertical axis. Knives unit which was designed as two parallel driven shafts with possibility of cranking circular and axial movement on a special support was installed inside of it. Cutting edges of circular blades are connected with grinding wire cup circles. As a result of experimental research the limit of performance of cutting elements in time space and cutting conditions during sharpening was found. The main problem in the design of cutting disc blades and selection of cutting regimes is their greasing by rubber sticking and fuming, and as a result – pollution of the environment. So, primarily task was to solve the problem with two contradictions: maximum performance of cutting process with the limited cutting speed, and elimination of tools heating to the melting point of the cord material. Limited cutting speed was determined experimentally. As a result of experimental researches rational cutting speed by circular knives within V=0,15-0,25 m/s was found. Diameter of disc blades due to conditions of the drive shaft strength, thickness of the conveyer belt, normal work conditions and other design parameters was selected. It was found that the outer diameter of blades is within 130-150 mm. Sharpening angle was selected experimentally and it is α = 12º, 19º, 25º and 30º. Due to result, of experiments and from the joint of view of stability and normal operation conditions it is recommended to take it within α = 16-22º. Criterion wearing allowance of disk blades was selected as 0,20 mm diameter, which is recommended and confirmed by our researches

Metal enrichment of the neutral gas of blue compact dwarf galaxies: the compelling case of Pox 36

We present the analysis of the interstellar spectrum of Pox 36 with the Far Ultraviolet Spectroscopic Explorer (FUSE). Pox 36 was selected because of the relatively low foreground gas content that makes it possible to detect absorption-lines weak enough that unseen components should not be saturated. Interstellar lines of HI, NI, OI, SiII, PII, ArI, and FeII are detected. Column densities are derived directly from the observed line profiles except for HI, whose lines are contaminated by stellar absorption. We used the TLUSTY models to remove the stellar continuum and isolate the interstellar component. The best fit indicates that the dominant stellar population is B0. The fit of the interstellar HI line gives a column density of 10^{20.3\pm0.4} cm-2. Chemical abundances were then computed from the column densities using the dominant ionization stage in the neutral gas. Our abundances are compared to those measured from emission-line spectra in the optical. Our results suggest that the neutral gas of Pox 36 is metal-deficient by a factor ~7 as compared to the ionized gas, and they agree with a metallicity of ~1/35 Z$_\odot$. Conclusions: The abundance discontinuity between the neutral and ionized phases implies that most of the metals released by consecutive star-formation episodes mixes with the HI gas. The volume extent of the enrichment is so large that the metallicity of the neutral gas increases only slightly. The star-forming regions could be enriched only by a small fraction (~1%), but it would greatly enhance its metallicity. Our results are compared to those of other BCDs. We confirm the overall underabundance of metals in their neutral gas, with perhaps only the lowest metallicity BCDs showing no discontinuity.Comment: Accepted for publication in A&

НАПРАВЛЕНИЯ ПОВЫШЕНИЯ КАЧЕСТВА ВНЕСЕНИЯ ПЕСТИЦИДОВ В ВЕТРЕНУЮ ПОГОДУ

The application of process solutions of pesticides in the field is inevitably accompanied by losses, which it is not possible to eliminate completely at this stage. The greatest damage to the environment is caused by the drifting of preparations off the treated object during treatment in windy weather. The process of drifting the drops of the process solution, taking into account the impact of environmental factors on them, has not been fully studied; consequently, the results of practical experiments can be different, sometimes contradictory. The issue of compliance with technological recommendations and use of technical devices that reduce or prevent the drifting of drops of working solutions when spraying crops remains relevant. The studies of the movement of pesticide drops under the influence of various factors, the directions of possible reduction of losses due to drifting and the use of various designs of windproof devices to field sprayers are considered in the paper. The results of experimental studies of quantitative and qualitative indicators of drifting using hydraulic sprayers are presented: slit Teejet TR40015E, vortex Lurmark 30НСX3 and centrifugal POK-0.6, as well as a windproof device made in the form of a louver grille. Drifting degree of the working fluid, characterized by the coefficient of targeted use of the fluid and the distance of drifting of droplets were taken as the objective functions. As a result, recommendations on the use of hydraulic sprayers of various types when spraying in windy weather and the technological parameters of a louvered windproof device are given and justified. The results obtained were implemented in development of agricultural machines for the band fertilizing during plant care of vegetables and can be used in the design and operation of field sprayers.Внесение рабочих растворов пестицидов в полевых условиях неизбежно сопровождается потерями, полностью исключить которые на данном этапе не представляется возможным. Наибольший урон окружающей среде наносит снос препаратов за пределы обрабатываемого объекта при обработках в ветреную погоду. Процесс сноса капель рабочего раствора с учетом воздействия на них факторов окружающей среды до конца не изучен, вследствие чего результаты практических экспериментов носят различный, иногда противоречивый характер. Актуальным остается вопрос соблюдения технологических рекомендаций и использования технических устройств, снижающих или предотвращающих снос капель рабочих растворов при опрыскивании сельскохозяйственных культур. В статье обобщен материал исследований движения капель пестицидов под воздействием различных факторов, обоснованы направления возможного снижения потерь из-за сноса и использования различных конструкций ветрозащитных устройств к полевым опрыскивателям. Представлены результаты экспериментальных исследований количественных и качественных показателей сноса при использовании гидравлических распылителей: щелевого Teejet ТР40015Е, вихревого Lurmark 30НСХ3 и центробежного РОК-0.6, а также ветрозащитного устройства, выполненного в виде жалюзийной решетки. В качестве целевых функций были приняты степень сноса рабочей жидкости, характеризуемая коэффициентом целевого использования жидкости, и дальность сноса капель. В результате даны рекомендации по использованию гидравлических распылителей различных типов при опрыскивании в ветреную погоду и обоснованы технологические параметры жалюзийного ветрозащитного устройства. Полученные результаты реализованы при разработке сельскохозяйственных машин для ленточного внесения гербицидов при уходе за посадками овощных культур и могут быть использованы при проектировании и эксплуатации полевых опрыскивателей.

Determining the neurotransmitter concentration profile at active synapses

Establishing the temporal and concentration profiles of neurotransmitters during synaptic release is an essential step towards understanding the basic properties of inter-neuronal communication in the central nervous system. A variety of ingenious attempts has been made to gain insights into this process, but the general inaccessibility of central synapses, intrinsic limitations of the techniques used, and natural variety of different synaptic environments have hindered a comprehensive description of this fundamental phenomenon. Here, we describe a number of experimental and theoretical findings that has been instrumental for advancing our knowledge of various features of neurotransmitter release, as well as newly developed tools that could overcome some limits of traditional pharmacological approaches and bring new impetus to the description of the complex mechanisms of synaptic transmission

Populations behind the source-subtracted cosmic infrared background anisotropies

While the upcoming telescopes will reveal correspondingly fainter, more distant galaxies, a question will persist: what more is there that these telescopes cannot see? One answer is the source-subtracted Cosmic Infrared Background (CIB). The CIB is comprised of the collective light from all sources remaining after known, resolved sources are accounted for. Ever-more-sensitive surveys will identify the brightest of these, allowing them to be removed, and - like peeling layers off an onion - reveal deeper layers of the CIB. In this way it is possible to measure the contributions from populations not accessible to direct telescopic observation. Measurement of fluctuations in the source-subtracted CIB, i.e., the spatial power spectrum of the CIB after subtracting resolved sources, provides a robust means of characterizing its faint, and potentially new, populations. Studies over the past 15 years have revealed source-subtracted CIB fluctuations on scales out to ~100' which cannot be explained by extrapolating from known galaxy populations. Moreover, they appear highly coherent with the unresolved Cosmic X-ray Background, hinting at a significant population of accreting black holes among the CIB sources. Characterizing the source-subtracted CIB with high accuracy, and thereby constraining the nature of the new populations, is feasible with upcoming instruments and would produce critically important cosmological information in the next decade. New coextensive deep and wide-area near-infrared, X-ray, and microwave surveys will bring decisive opportunities to examine, with high fidelity, the spatial spectrum and origin of the CIB fluctuations and their cross-correlations with cosmic microwave and X-ray backgrounds, and determine the formation epochs and the nature of the new sources (stellar nucleosynthetic or accreting black holes).Comment: Science whitepaper submitted to the Astro2020 Decadal Surve