Time filter

Source Type

Ratkiewicz R.,Polish Institute of Aviation | Ratkiewicz R.,Polish Academy of Sciences | Strumik M.,Polish Academy of Sciences | Grygorczuk J.,Polish Academy of Sciences
Astrophysical Journal | Year: 2012

We study the effects of the strength and direction of the local interstellar magnetic field (ISMF) on the heliosphere geometry that generates the locus of points associated with the position of the IBEX ribbon of energetic neutral atoms. MHD heliosphere models are run for a variety of ISMF parameters to specifically study the correlation between locations of maxima of the ISMF magnitude along the field lines and places where the local ISMF B is perpendicular to radial vectors r from the Sun, i.e., B · r = 0. The study confirms the existence of a strong physical relationship between the ribbon and the ISMF. © © 2012. The American Astronomical Society. All rights reserved..

Zielinski P.,Polish Institute of Aviation
Journal of Psychophysiology | Year: 2016

The purpose of the experiment was to test the relationship between attributes of color, self-rated arousal, and autonomic reactions to color stimuli. Sixteen colored backgrounds of different hue, saturation, and brightness were each viewed by 64 subjects (females, Mage = 22.48) while skin conductance responses (SCRs) were recorded. Subjective judgments relating to pleasantness (valence) and arousal were also measured. Results show that among color attributes only saturation had an effect on SCR magnitude, F(1, 63) = 6.31, p <.05,ŋG 2 =.01. There was also significant correlation, r(14) =.64, p <.01, between aggregated SCR magnitude and arousal ratings. It confirms that SCR could be used as a marker of phasic arousal even in response to the abstract, devoid of content stimuli. Saturation seems to be the main property connected with color’s ability to elicit orienting response. More saturated stimuli are better in capturing attention regardless of hue, thus suggesting that at the first stage of color perception, color intensity is more important than qualitative properties. Such results clarify some incoherent findings known from previous studies on psychophysiological responses to color stimuli. © 2015 Hogrefe Publishing.

Ben-Jaffel L.,CNRS Paris Institute of Astrophysics | Strumik M.,Polish Academy of Sciences | Ratkiewicz R.,Polish Academy of Sciences | Ratkiewicz R.,Polish Institute of Aviation | Grygorczuk J.,Polish Academy of Sciences
Astrophysical Journal | Year: 2013

We report a new diagnosis of two different states of the local interstellar medium (LISM) near our solar system by using a sensitivity study constrained by several distinct and complementary observations of the LISM, solar wind, and inner heliosphere. Assuming the Interstellar Boundary Explorer (IBEX) He flow parameters for the LISM, we obtain a strength of ∼2.7 ± 0.2 μG and a direction pointing away from galactic coordinates (28, 52) ± 3° for the interstellar magnetic field as a result of fitting Voyager 1 and Voyager 2 in situ plasma measurements and IBEX energetic neutral atoms ribbon. When using Ulysses parameters for the LISM He flow, we recently reported the same direction but with a strength of 2.2 ± 0.1 μG. First, we notice that with Ulysses He flow, our solution is in the expected hydrogen deflection plane (HDP). In contrast, for the IBEX He flow, the solution is ∼20° away from the corresponding HDP plane. Second, the long-term monitoring of the interplanetary H I flow speed shows a value of ∼26 km s-1 measured upwind from the Doppler shift in the strong Lyα sky background emission line. All elements of the diagnosis seem therefore to support Ulysses He flow parameters for the interstellar state. In that frame, we argue that reliable discrimination between superfast, subfast, or superslow states of the interstellar flow should be based on most existing in situ and remote observations used together with global modeling of the heliosphere. For commonly accepted LISM ionization rates, we show that a fast interstellar bow shock should be standing off upstream of the heliopause. © 2013. The American Astronomical Society. All rights reserved.

The issues involved with recording vital functions in the magnetic resonance imaging (MRI) environment using fiber-optic sensors are considered in this paper. Basic physiological parameters, such as respiration and heart rate, are fundamental for predicting the risk of anxiety, panic, and claustrophobic episodes in patients undergoing MRI examinations. Electronic transducers are generally hazardous to the patient and are prone to erroneous operation in heavily electromagnetically penetrated MRI environments; however, nonmetallic fiberoptic sensors are inherently immune to electromagnetic effects and will be crucial for acquiring the abovementioned physiological parameters. Forty-seven MRI-tested or potentially MRI-compatible sensors have appeared in the literature over the last 20 years. The author classifies these sensors into several categories and subcategories, depending on the sensing element placement, method of application, and measurand type. The author includes five in-house-designed fiber Bragg grating based sensors and shares experience in acquiring physiological measurements during MRI scans. This paper aims to systematize the knowledge of fiber-optic techniques for recording life functions and to indicate the current directions of development in this area. © The Authors.

Kozak J.,Polish Institute of Aviation
Lecture Notes in Electrical Engineering | Year: 2013

Electrochemical machining (ECM) is an important manufacture technology in machining difficult-to-cut materials and to shape complicated contours and profiles with high material removal rate without tool wear and without inducing residual stress. This paper presents the physical and mathematical models on the basis of which of the simulation process module in the computer-aided engineering system (CAE-ECM) for ECM has been developed. The results of computer simulation of electrochemical sinking and examples of CAE-ECM system application are discussed. © 2013 Springer Science+Business Media.

Discover hidden collaborations