14 research outputs found
Dust Devil Tracks
Dust devils that leave dark- or light-toned tracks are common on Mars and they can also be found on the Earth’s surface. Dust devil tracks (hereinafter DDTs) are ephemeral surface features with mostly sub-annual lifetimes. Regarding their size, DDT widths can range between ∼1 m and ∼1 km, depending on the diameter of dust devil that created the track, and DDT lengths range from a few tens of meters to several kilometers, limited by the duration and horizontal ground speed of dust devils. DDTs can be classified into three main types based on their morphology and albedo in contrast to their surroundings; all are found on both planets: (a) dark continuous DDTs, (b) dark cycloidal DDTs, and (c) bright DDTs. Dark continuous DDTs are the most common type on Mars. They are characterized by their relatively homogenous and continuous low albedo surface tracks. Based on terrestrial and martian in situ studies, these DDTs most likely form when surficial dust layers are removed to expose larger-grained substrate material (coarse sands of ≥500 μm in diameter). The exposure of larger-grained materials changes the photometric properties of the surface; hence leading to lower albedo tracks because grain size is photometrically inversely proportional to the surface reflectance. However, although not observed so far, compositional differences (i.e., color differences) might also lead to albedo contrasts when dust is removed to expose substrate materials with mineralogical differences. For dark continuous DDTs, albedo drop measurements are around 2.5 % in the wavelength range of 550–850 nm on Mars and around 0.5 % in the wavelength range from 300–1100 nm on Earth. The removal of an equivalent layer thickness around 1 μm is sufficient for the formation of visible dark continuous DDTs on Mars and Earth. The next type of DDTs, dark cycloidal DDTs, are characterized by their low albedo pattern of overlapping scallops. Terrestrial in situ studies imply that they are formed when sand-sized material that is eroded from the outer vortex area of a dust devil is redeposited in annular patterns in the central vortex region. This type of DDT can also be found in on Mars in orbital image data, and although in situ studies are lacking, terrestrial analog studies, laboratory work, and numerical modeling suggest they have the same formation mechanism as those on Earth. Finally, bright DDTs are characterized by their continuous track pattern and high albedo compared to their undisturbed surroundings. They are found on both planets, but to date they have only been analyzed in situ on Earth. Here, the destruction of aggregates of dust, silt and sand by dust devils leads to smooth surfaces in contrast to the undisturbed rough surfaces surrounding the track. The resulting change in photometric properties occurs because the smoother surfaces have a higher reflectance compared to the surrounding rough surface, leading to bright DDTs. On Mars, the destruction of surficial dust-aggregates may also lead to bright DDTs. However, higher reflective surfaces may be produced by other formation mechanisms, such as dust compaction by passing dust devils, as this may also cause changes in photometric properties. On Mars, DDTs in general are found at all elevations and on a global scale, except on the permanent polar caps. DDT maximum areal densities occur during spring and summer in both hemispheres produced by an increase in dust devil activity caused by maximum insolation. Regionally, dust devil densities vary spatially likely controlled by changes in dust cover thicknesses and substrate materials. This variability makes it difficult to infer dust devil activity from DDT frequencies. Furthermore, only a fraction of dust devils leave tracks. However, DDTs can be used as proxies for dust devil lifetimes and wind directions and speeds, and they can also be used to predict lander or rover solar panel clearing events. Overall, the high DDT frequency in many areas on Mars leads to drastic albedo changes that affect large-scale weather patterns
The long-term effects of denominational secondary schools | Langfristige Einflüsse der konfessionellen Mittelschule
In the present study we examined the graduate students of higher educational institutions with
Hungarian as the language of teaching in Hungary, Rumania and the Ukraine. We were interested
in seeing whether divergences could be traced, years after graduation, among students
coming from certain secondary school sectors. Our results revealed that the more advantageous
situation of former denominational high school students could be detected especially in the
attitude to one’s work, the work concept of serving the common good, and the consumption of
intellectual high culture in the traditional sense. These achievements of former denominational
school students could not be explained with their social status, since these young people, in
many respects, are more disadvantaged than the average. However, their value system and relationship
network, and most of all their religiosity have a characteristic aspect. In regression
models, we matched the strength of the seemingly significant explanations in the two-variable
analysis. On the basis of the matching, we found that minding the influence of other explanations,
regarding the readiness of entering service, the work concept of seeking social utility, as
well as time spent on reading, sector-effect (effect of school maintainer) carries a very remarkable
weight. After the passing of denominational school-years the personal or small-community
worship can also inspire the formation or observance of this type of work concept, the
attendance of students’ extracurricular tasks and the classical intellectual leisure time habits. |
In vorliegender Studie untersuchten
wir Absolventen von Hochschulen in Ungarn und in grenznahen ungarischsprachigen Gebieten
in Rumänien und der Ukraine unter dem Gesichtspunkt, ob Jahre nach dem Abitur Unterschiede zwischen den Studenten aus verschiedenen Mittelschulsektoren festzustellen seien. Die Ergebnisse
zeigten, dass sich der Vorsprung der ehemaligen Schüler der konfessionellen Schulen vor
allem in der Einstellung zur Berufstätigkeit, einer dem Gemeinwohl verpflichteten Arbeitseinstellung
und der Teilnahme am kulturellen Leben der im herkömmlichen Sinne Intellektuellen
zeigt. Die Leistungen der einstigen Schüler der konfessionellen Schulen in diesen Bereichen
lassen sich nicht durch den gesellschaftlichen Status der Studenten erklären, da diese Jugendlichen
in vielerlei Hinsicht schlechter gestellt sind als der Durchschnitt; ihr Werte- und Beziehungssystem
sowie ihre Religiosität besitzen jedoch eine charakteristische Ausprägung. Die
Stichhaltigkeit der in der bivariablen Analyse signifikant erscheinenden Erklärungen untersuchten
wir anhand regressiver Modelle. Auf dieser Grundlage stellten wir fest, dass dem Einfluss
des Schulsektors bezüglich der Bereitschaft zur Berufstätigkeit, einer dem gesellschaftlichen
Nutzen verpflichteten Arbeitseinstellung und der auf das Lesen verwendeten Zeit auch
unter Berücksichtigung des Einflusses anderer möglicher Erklärungen ausgesprochen große
Bedeutung beizumessen ist. Im Anschluss an die in der konfessionellen Schule verbrachte Zeit
sorgen auch die individuelle und die in kleinen Gemeinschaften gelebte Glaubenspraxis für die
Entwicklung bzw. Wahrung der obigen Arbeitsauffassung, der Beteiligung der Studenten an
extracurriculären Aufgaben und der klassischen Freizeitgestaltung der Intellektuellen. |
Jelen tanulmányban Magyarország, Románia és Ukrajna határmenti, magyar tanítási nyelvű felsőoktatási intézményeinek végzős hallgatóit vizsgáltuk abból a szempontból, hogy kimutathatóak-e eltérések az egyes középiskolai szektorokból érkező hallgatók között évekkel az érettségi után. Az eredményeink azt mutatták, hogy főképpen a munkába álláshoz való viszony, a közjót szolgáló munkafelfogás és a hagyományos értelemben vett értelmiségi magaskultúra fogyasztása terén mutatható ki az egykori felekezeti középiskolások előnye. Az egykori felekezeti iskolások ezen teljesítménye nem magyarázható a hallgatók társadalmi státusával, hiszen ezek a fiatalok több vonatkozásban hátrányosabb helyzetűek az átlagnál, azonban karakteres arculata van az értékrendjüknek és a kapcsolatrendszerüknek, de leginkább a vallásosságuknak. A kétváltozós elemzésben szignifikánsnak tűnő magyarázatok erejét regressziós modellekben mértük össze. Ennek alapján megállapítottuk, hogy a munkába állási készség, a társadalmi hasznosságra törekvő munkafelfogás, valamint az olvasásra fordított idő vonatkozásában más magyarázatok befolyását is figyelembe véve kifejezetten jelentős súlya van a szektorhatásnak. A felekezeti iskolás évek elmúltával a személyes és a kisközösségi vallásgyakorlat is ösztönzi az ilyen típusú munkafelfogást, a hallgatói extrakurrikuláris feladatokban való részvételt és a klasszikus értelmiségi szabadidős szokások kialakulását, valamint mindezek megtartását is
Populations of small craters on Europa, Ganymede, and Callisto: initial Galileo imaging results
Changes in oxygen saturation following low-dose intramuscular ketamine in paediatric cardiac surgical patients
Carotid sinus syncope treated by pacing. Analysis of persistent symptoms and role of atrioventricular sequential pacing.
The Dawn Framing Camera
The Framing Camera (FC) is the German contribution to the Dawn mission. The camera will map 4 Vesta and 1 Ceres through a clear filter and 7 band-pass filters covering the wavelengths from the visible to the near-IR. The camera will allow the determination of the physical parameters of the asteroids, the reconstruction of their global shape as well as local topography and surface geomorphology, and provide information on composition via surface reflectance characteristics. The camera will also serve for orbit navigation. The resolution of the Framing Camera will be up to 12 m per pixel in low altitude mapping orbit at Vesta (62 m per pixel at Ceres), at an angular resolution of 93.7 �¼radâ��pxâ��1.
The instrument uses a reclosable front door to protect the optical system and a filter-wheel mechanism to select the band-pass for observation. The detector data is read out and processed by a data processing unit. A power converter unit supplies all required power rails for operation and thermal maintenance. For redundancy reasons, two identical cameras were provided, both located side by side on the +Z-deck of the spacecraft. Each camera has a mass of 5.5 kg