Cassini's floating potential in Titan's ionosphere: 3-D particle-in-cell simulations

Accurate determination of Cassini’s spacecraft potential in Titan’s ionosphere is important for interpreting measurements by its low energy plasma instruments. Estimates of the floating potential varied significantly, however, between the various different plasma instruments. In this study we utilize 3-D particle-in-cell simulations to understand the key features of Cassini’s plasma interaction in Titan’s ionosphere. The spacecraft is observed to charge to negative potentials for all scenarios considered, and close agreement is found between the current onto the simulated Langmuir Probe and that observed in Titan’s ionosphere. These simulations are therefore shown to provide a viable technique for modeling spacecraft interacting with Titan’s dusty ionosphere

Solar cycle modulation of Titan's ionosphere

This is the publisher's version, also available electronically from http://onlinelibrary.wiley.com/doi/10.1002/jgra.50463/abstractDuring the six Cassini Titan flybys T83–T88 (May 2012 to November 2012) the electron density in the ionospheric peak region, as measured by the radio and plasma wave science instrument/Langmuir probe, has increased significantly, by 15–30%, compared to previous average. These measurements suggest that a long‒term change has occurred in the ionosphere of Titan, likely caused by the rise to the new solar maximum with increased EUV fluxes. We compare measurements from TA, TB, and T5, from the declining phase of solar cycle 23 to the recent T83–T88 measurements during cycle 24, since the solar irradiances from those two intervals are comparable. The peak electron densities normalized to a common solar zenith angle Nnorm from those two groups of flybys are comparable but increased compared to the solar minimum flybys (T16–T71). The integrated solar irradiance over the wavelengths 1–80nm, i.e., the solar energy flux, Fe, correlates well with the observed ionospheric peak density values. Chapman layer theory predicts that inline image, with k=0.5. We find observationally that the exponent k=0.54±0.18. Hence, the observations are in good agreement with theory despite the fact that many assumptions in Chapman theory are violated. This is also in good agreement with a similar study by Girazian and Withers (2013) on the ionosphere of Mars. We use this power law to estimate the peak electron density at the subsolar point of Titan during solar maximum conditions and find it to be about 6500cm−3, i.e., 85–160% more than has been measured during the entire Cassini mission

Saturn’s near-equatorial ionospheric conductivities from in situ measurements

Cassini’s Grand Finale orbits provided for the first time in-situ measurements of Saturn’s topside ionosphere. We present the Pedersen and Hall conductivities of the top near-equatorial dayside ionosphere, derived from the in-situ measurements by the Cassini Radio and Wave Plasma Science Langmuir Probe, the Ion and Neutral Mass Spectrometer and the fluxgate magnetometer. The Pedersen and Hall conductivities are constrained to at least 10⁻⁵–10⁻⁴ S/m at (or close to) the ionospheric peak, a factor 10–100 higher than estimated previously. We show that this is due to the presence of dusty plasma in the near-equatorial ionosphere. We also show the conductive ionospheric region to be extensive, with thickness of 300–800 km. Furthermore, our results suggest a temporal variation (decrease) of the plasma densities, mean ion masses and consequently the conductivities from orbit 288 to 292

Дискримінація в спорті як грубе порушення прав людини в Україні

The urgency of the problem described in the article is the existence of an ineffective observance mechanism of athletes' and fans' rights in connection with the manifestations of discrimination in sports. Therefore, the purpose of the article is to find ways to improve Ukrainian legislation in terms of protection of human rights from any manifestations of discrimination. To achieve this goal, the system-structural method and the formal-legal method, the method of analysis, the formal-logical method were used. The Ukrainian legislation in the researched field is analyzed. The experience of other countries in combating discrimination in sports has been studied. It is proposed to create an institute of sports ombudsman in Ukraine and stressed the need not to improve the criminal legislation in terms of clarifying the provisions of Article 161 of the Criminal Code of Ukraine. The expediency of establishing administrative liability for non-compliance with anti-discrimination legislation, amending the Code of Ukraine on Administrative Offenses, which, in turn, will facilitate more prompt prosecution for human rights violations in sports. The practical value of the obtained results is that it can be taken as a basis for finding a mechanism to improve the fight against discrimination in sports.Актуальність описаної в статті проблеми зумовлена існуванням неефективного механізму дотримання прав спортсменів і вболівальників у зв’язку з проявами дискримінації в спорті. Тому мета статті полягає у пошуку напрямків удосконалення українського законодавства у частині захисту прав людини від будь-яких проявів дискримінації. Для досягнення поставленої мети було використано системно-структурний метод і формально-юридичний метод, метод аналізу, формально-логічний метод. У статті розглянуто правові основи порушення прав людини у зв’язку з дискримінацією у спорті. Проаналізовано українське законодавство у досліджуваній сфері. Досліджено досвід інших країн щодо протидії та боротьби з дискримінацією у спорті. Запропоновано створити інститут спортивного омбудсмена в Україні та наголошено не необхідності удосконалення кримінального законодавства у частині уточнення диспозиції статті 161 Кримінального кодексу України. Вказано на доцільність встановлення адміністративної відповідальності за недодержання антидискримінаційного законодавства, внісши відповідні зміни до Кодексу України про адміністративні правопорушення, що, своєю чергою, сприятиме більш оперативному притягненню до відповідальності за порушення прав людини у сфері спорту. Практична цінність отриманих результатів полягає в тому, що останні можуть бути взяті за основу при пошуку механізму удосконалення протидії та боротьби з дискримінацією у сфері спорту

Manifestations of Culture in Website Design

The web is a global phenomenon and its reach and influence ignores political and cultural boundaries. However, the web’s global presence and easy accessibility does not also mean there are no issues related to the understanding and interpretations of its content. Of particular interest to us is to find out whether there is any effect of culture on web design. In this paper, we report on our research into the identification of elements that can be attributed to culture on website design. We examined and compared South Korean and UK’s charity websites and identified these elements of the websites. The findings suggest that there are some differences and preferences in the website design that are mostly related to whether the websites employ multimedia and provide facilities for user input. <!--EndFragment--

Titan conductivities (Cassini)

This is the dataset for the article &quot;Conductivities of Titan&apos;s dusty ionosphere&quot;, Journal of Geophysical Research: Space Physics, DOI: 10.1029/2021JA029910Please see the article for the description and references for data derivations.ephemerides.xlsx contents (one flyby per sheet):UTC time stampaltitude [km] altitude above Titan surfacesc_Velocity [km/s] magnitude of Cassini spacecraft velocitySolar_Zenith_Angle [degrees] angle from the Sun direction (X-axis in solar ecliptic coordinates)sub_solar_lat [degrees] of sub-solar latitude (i.e. Titan geographic latitude where Sun is in zenith)Saturn_Local_time [hours] azimuthal coordinate of Cassini with respect to SaturnLocal_Time [hours] azimuthal coordinate of Cassini with respect to TitanLat [degrees] Titan geographic latitudeWest_Long [degrees] Titan geographic longitude, counted westwardRx_ecl_km, Ry_ecl_km, Rz_ecl_km [km] Titan-centered solar ecliptic coordinates of Cassini (X-axis towards Sun, Z-axis is the component of Titan angular rotation vector orthogonal to X, Y-axis completes right-handed set)input_data.xlsx contents (one flyby per sheet)% &lt;variable&gt;_err is the 2-sigma uncertainty in the same units as the variableUTC time stampN2 [cm^-3] molecular nitrogen number densityCH4 [cm^-3] methane number densityNe [cm^-3] electron charge densityNi [cm^-3] positive ion charge densityZN [cm^-3] negative dust charge number densityTe [K] electron temperatureTi [K] positive ion temperatureTd [K] negative dust temperatureZd mean negative dust charge numberMi [amu] mean positive ion massMd [amu] mean negative ion massB [T] magnetic fieldconductivities.xlsx contents (one flyby per sheet):% &lt;variable&gt;_err is the 2-sigma uncertainty in the same units as the variableUTC time stampnyElectrons [s^-1] total electron momentum transfer collision frequencynyIons [s^-1] total positive ion momentum transfer collision frequencynyDust [s^-1] total negative dust momentum transfer collision frequencysig_Parallel [S/m] field-parallel conductivitysig_Pedersen [S/m] Pedersen conductivitysig_Hall [S/m] Hall conductivitycasesl.xlsx contents (one time stamp per sheet):% &lt;variable&gt;_err is the 2-sigma uncertainty in the same units as the variableUTC time stampaltitude [km] altitude above Titan surfaceZd mean negative dust charge numbersig_Par [S/m] field-parallel conductivity for given Zdsig_P [S/m] Pedersen conductivity for given Zdsig_H [S/m] Hall conductivity for given Zdmi_spec [amu] positive ion mass spectra (INMS &amp; IBS combined)Ni_spec [cm^-3] positive ion charge density as a function of massmd_spec [amu] negative dust/ion mass spectra (ELS)Nd_spec [cm^-3] negative dust/ion charge density as a function of mas

Titan conductivities (Cassini)

This is the dataset for the article &quot;Conductivities of Titan&apos;s dusty ionosphere&quot;, Journal of Geophysical Research: Space Physics, DOI: 10.1029/2021JA029910Please see the article for the description and references for data derivations.ephemerides.xlsx contents (one flyby per sheet):UTC time stampaltitude [km] altitude above Titan surfacesc_Velocity [km/s] magnitude of Cassini spacecraft velocitySolar_Zenith_Angle [degrees] angle from the Sun direction (X-axis in solar ecliptic coordinates)sub_solar_lat [degrees] of sub-solar latitude (i.e. Titan geographic latitude where Sun is in zenith)Saturn_Local_time [hours] azimuthal coordinate of Cassini with respect to SaturnLocal_Time [hours] azimuthal coordinate of Cassini with respect to TitanLat [degrees] Titan geographic latitudeWest_Long [degrees] Titan geographic longitude, counted westwardRx_ecl_km, Ry_ecl_km, Rz_ecl_km [km] Titan-centered solar ecliptic coordinates of Cassini (X-axis towards Sun, Z-axis is the component of Titan angular rotation vector orthogonal to X, Y-axis completes right-handed set)input_data.xlsx contents (one flyby per sheet)% &lt;variable&gt;_err is the 2-sigma uncertainty in the same units as the variableUTC time stampN2 [cm^-3] molecular nitrogen number densityCH4 [cm^-3] methane number densityNe [cm^-3] electron charge densityNi [cm^-3] positive ion charge densityZN [cm^-3] negative dust charge number densityTe [K] electron temperatureTi [K] positive ion temperatureTd [K] negative dust temperatureZd mean negative dust charge numberMi [amu] mean positive ion massMd [amu] mean negative ion massB [T] magnetic fieldconductivities.xlsx contents (one flyby per sheet):% &lt;variable&gt;_err is the 2-sigma uncertainty in the same units as the variableUTC time stampnyElectrons [s^-1] total electron momentum transfer collision frequencynyIons [s^-1] total positive ion momentum transfer collision frequencynyDust [s^-1] total negative dust momentum transfer collision frequencysig_Parallel [S/m] field-parallel conductivitysig_Pedersen [S/m] Pedersen conductivitysig_Hall [S/m] Hall conductivitycasesl.xlsx contents (one time stamp per sheet):% &lt;variable&gt;_err is the 2-sigma uncertainty in the same units as the variableUTC time stampaltitude [km] altitude above Titan surfaceZd mean negative dust charge numbersig_Par [S/m] field-parallel conductivity for given Zdsig_P [S/m] Pedersen conductivity for given Zdsig_H [S/m] Hall conductivity for given Zdmi_spec [amu] positive ion mass spectra (INMS &amp; IBS combined)Ni_spec [cm^-3] positive ion charge density as a function of massmd_spec [amu] negative dust/ion mass spectra (ELS)Nd_spec [cm^-3] negative dust/ion charge density as a function of massTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

PIC simulation data of Cassini during the grand finale

This is the simulation data used in the publication Zhang et al. (2021): Particle-In-Cell Simulations of the Cassini Spacecraft's Interaction with Saturn's Ionosphere during the Grand Finale. This article was accepted on 8th March 2021, and full details on these simulations can be found in this article