Volcanism on Venus: Large shields and major accumulations of small domes

The outer layers of the Venusian lithosphere appear to dissipate heat from the interior through mantle-driven thermal anomalies (hot spots, swells). As a result, Venus exhibits diverse forms of thin-skin tectonism and magmatic transfer to and extrusion from countless numbers of volcanic centers (e.g., shields, paterae, domes) and volcano-tectonic complexes (e.g., coronae, arachnoids). What is known about the distribution and morphologies of major Venusian shields is summarized, and the evidence for possible structural control of major accumulations as long as 5000 km of small volcanic domes is described

Comments on the tectonism of Venus

Preliminary tectonic mapping of Venus from Venera 15/16 images shows unquestionable evidence of at least limited horizontal tectonism. The majority of tectonic features on Venus have no relation to topography. In fact, many axes of disruption interconnect, and cross sharp topographic boundaries at large angles, thereby discounting gravity as the driving force. Compressional zones (CZ's), unlike Extensional zones (EZ's), tend to be discontinuous, and, whereas EZ's cross tectonic and topographic boundaries at various angles, many CZ's on Venus are subparallel to these boundaries. Strike-like faulting is curiously lacking from the mapping, possible due to the steep incidence angle of the radar, which is far from optimal for detecting faults of small throw. A chronology of horizontal crustal movements, and hence the analysis of Venus' thermal development, is large dependent on understanding the crater form features. Regardless of their uncertain origin, the craters still could hold the answer to whether, and to what extent, crustal shuffling is occurring on Venus

Clotho Tessera, Venus: A fragment of Fortuna Tessera

Clotho Tessera, adjacent to southeast Lakshmi Planum, may provide additional evidence for lateral crustal motions, and a model for the origin of small tessera fragments. Clotho Tessera and Lakshmi Planum are so noticeably different, and in such close proximity, it is difficult to derive a reasonable model of their formation in situ. Squeezing of material out from beneath Lakshmi has been suggested as an origin for Moira Tessera, which is also adjacent to Lakshmi and 1400 km west of Clotho. However, a logical model of juxtaposition of the two different terrains, originally from points once distant, can be made for Clotho and Lakshmi (and perhaps other small tesserae as well). It is suggested that Clotho Tessera was once part of Fortuna Tessera, but was cut off by a transcurrent fault zone (the DLZ) striking perpendicular to the Sigrun rift and carried westward where it collided with Lakshmi Planum (forming Danu Montes). A gravity anomaly along the southern border of Lakshmi, in the area of Danu Montes, was interpreted as indicating subduction there, providing additional supporting evidence for the collision hypothesis. Diffusion of the DLZ with proximity to Sigrun Fossae may be due to either higher ductility near the postulated Sigrun rift, or to burial by flows away from the rift nearer to Valkyrie Fossae. Other possible examples of migrating tesserae occur elsewhere: small pieces of Ananke Tessera can be fit back together as though they had rifted apart, and the spreading apart of Ananke and Virilis Tesserae has been suggested because of their symmetric locations about the axis of an inferred spreading zone. Other tessera fragments appear to have been isolated by rifting, with little, if any, significant lateral motion (e.g., Meni and Tellus Tesserae, and Thethus and Fortuna Tesserae). The migrating terrain model for Clotho Tessera supports Sukhanov's interpretation of tesseral fragments as rafts of lighter crustal material

Измерение скорости просачивания трансформаторного масла через электротехнический картон

The paper presents a new test stand for ivestigating the rate of penetration of transformer oil through electrotechnical pressboard. The stand consists of a pipe, to the lower end of which is glued a pressboard plate. The pipe is filled with insulating oil. A mirror is placed under the plate, which directs its image to the lens of the camera, which takes a series of photographs at a given time interval. After being saturated with the insulating oil, the pressboard changes colour from light to dark yellow. The absorbing time is defined as the time in which a dark yellow spot appears on the lower light surface of the pressboard after the pipe is filled with oil. A new way of determining capillary diameters has been developed when the number of capillaries is unknown and the volume of liquid flowing through them is not measurable. The distribution of the times of penetration of transformer oil through 2 mm thick electrotechnical pressboard was determined, the values of which range from about 220 min to about 550 min. It was found that the radii of capillaries through which the insulating oil penetrates are within the range from about 45 nm to about 70 nm. Due to the structure of the pressboard, which consists of cellulose fibres, arranged more or less tightly, there are capillaries in the structure of the board, each of which has sections of varying lengths of radii. This means that short sections of a single capillary can have radii both smaller than 45 nm and larger than 70 nm. The developed stand and the new analysis method can be used for testing various porous materials for penetration by various liquids

Multiple Model Methods for Cost Function Based Multiple Hypothesis Trackers

Multiple hypothesis trackers (MHTs) are widely accepted as the best means of tracking targets in clutter. This research seeks to incorporate multiple model Kalman filters into an Integral Square Error (ISE) cost-function-based MHT to increase the fidelity of target state estimation. Results indicate that the proposed multiple model methods can properly identify the maneuver mode of a target in dense clutter and ensure that an appropriately tuned filter is used. During benign portions of flight, this causes significant reductions in position and velocity RMS errors compared to a single-filter MHT. During portions of flight when the mixture mean deviates significantly from true target position, so-called deferred decision periods, the multiple model structures tend to accumulate greater RMS errors than a single-filter MHT, but this effect is inconsequential considering the inherently large magnitude of these errors (a non-MHT tracker would not be able to track during these periods at all). The multiple model MHT structures do not negatively impact track life when compared to a single-filter MHT

Digital solar system geology

All available synoptic maps of the solid-surface bodies of the Solar System were digitized for presentation in the planned Atlas of the Solar System by Greeley and Batson. Since the last report (Batson et al., 1990), preliminary Uranian satellite maps were replaced with improved versions, Galilean satellite geology was simplified and digitized, structure was added to many maps, and the maps were converted to a standard format, with corresponding standing colors for the mapped units. Following these changes, the maps were re-reviewed by their authors and are now undergoing final editing before preparation for publication. In some cases (for Mercury, Venus, and Mars), more detailed maps were digitized and then simplified for the Atlas. Other detailed maps are planned to be digitized in the coming year for the Moon and the Galilean satellites. For most of the remaining bodies such as the Uranian satellites, the current digitized versions contain virtually all the detail that can be mapped given the available data; those versions will be unchanged for the Atlas. These digital geologic maps are archived at the digital scale of 1/16 degree/ pixel, in sinusoidal format. The availability of geology of the Solar System in a digital database will facilitate comparisons and integration with other data: digitized lunar geologic maps have already been used in a comparison with Galileo SSI observations of the Moon

A preferred vision for administering secondary schools : a reflective essay

Teachers and principals need to work cooperatively to evaluate programs and make suggestions for the betterment of the students. The principal needs to involve the faculty, parents, community, and businesses to help develop a long-lasting relationship between the school and the outside world. Above all, it is the absolutely necessary for administrators to cultivate trust, confidence, integrity, and moral responsibility within the school. If I can create opportunities for educators to feel good about themselves, they will pass this feeling on to students and then into the community. By embracing these components of effective leadership, effective schools will result

Impact cratering and the surface age of Venus: The Pre-Magellan controversy

The average surface age of a planet is a major indicator of the level of its geologic activity and thus of the dynamics of its interior. Radar images obtained by Venera 15/16 from the northern quarter of the Venus (lat 30 to 90 degs) reveal about 150 features that resemble impact craters, and they were so interpreted by Soviet investigators B. A. Ivanov, A. T. Basilevsky, and their colleagues. These features range in diameter from about 10 to 145 km. Their areal density is remarkably similar to the density of impact structures found on the American and European continental shields. The basic difference between the Soviet and American estimates of the average surface age of Venus's northern quarter is due to which crater-production rate is used for the Venusian environment. Cratering rates based on the lunar and terrestrial cratering records, as well as statistical calculations based on observed and predicted Venus-crossing asteroids and comets, have been used in both the Soviet and American calculations. The single largest uncertainty in estimating the actual cratering rates near Venus involves the shielding effect of the atmosphere

Измерение скорости просачивания трансформаторного масла через электротехнический картон

The paper presents a new test stand for ivestigating the rate of penetration of transformer oil through electrotechnical pressboard. The stand consists of a pipe, to the lower end of which is glued a pressboard plate. The pipe is filled with insulating oil. A mirror is placed under the plate, which directs its image to the lens of the camera, which takes a series of photographs at a given time interval. After being saturated with the insulating oil, the pressboard changes colour from light to dark yellow. The absorbing time is defined as the time in which a dark yellow spot appears on the lower light surface of the pressboard after the pipe is filled with oil.A new way of determining capillary diameters has been developed when the number of capillaries is unknown and the volume of liquid flowing through them is not measurable. The distribution of the times of penetration of transformer oil through 2 mm thick electrotechnical pressboard was determined, the values of which range from about 220 min to about 550 min. It was found that the radii of capillaries through which the insulating oil penetrates are within the range from about 45 nm to about 70 nm. Due to the structure of the pressboard, which consists of cellulose fibres, arranged more or less tightly, there are capillaries in the structure of the board, each of which has sections of varying lengths of radii. This means that short sections of a single capillary can have radii both smaller than 45 nm and larger than 70 nm.The developed stand and the new analysis method can be used for testing various porous materials for penetration by various liquids. В работе представлена новая установка для исследования скорости просачивания трансформаторного масла через электротехнический картон. Установка состоит из прозрачной трубы, к нижнему концу которой приклеена пластинка электротехнического картона. Затем в трубу вливается трансформаторное масло. Под пластинкой находится зеркало, направляющее её изображение в объектив фотоаппарата, который регистрирует серию изображений пластинки с заданным временным интервалом. Электротехнический картон, смоченный трансформаторным маслом, изменяет свой цвет со светло-жёлтого на тёмно-жёлтый. Время просачивания трансформаторного масла через электротехнический картон определяется по появлению на изображении поверхности картона тёмно-жёлтого пятнышка, свидетельствующего о просачивании трансформаторного масла через пластинку.Разработан способ расчёта среднего диаметра капилляров, через которые трансформаторное масло просачивается через электротехнический картон в случае, когда их число является неизвестным, в связи с чем объём вытекающей через один капилляр жидкости невозможно измерить. Установлено, что в разных местах пластинки картона с толщиной 1 мм времена просачивания различаются. На основании проведённых измерений определено распределение времён просачивания, которые изменяются от 224 мин до 556 мин. Рассчитаны радиусы капилляров, через которые трансформаторное масло просачивается через электротехнический картон. Их величины изменяются от 47 нм до 75 нм. Структура картона представляет собой волокна целлюлозы, упакованные достаточно плотно. В связи с этим между волокнами существуют капилляры, каждый из которых состоит из участков с изменяющимися по длине радиусами. Таким образом, в картоне имеются короткие участки капилляров с радиусами как меньшими 47 нм, так и большими 75 нм.Разработанные установка и способ расчёта размеров капилляров могут быть использованы для исследования протекания различных жидкостей через пористые материалы

Selfie-Objectification: Does Taking One’s Own Picture Increase Levels of State Self-Objectification among College Females?

The current experiment investigated the effects of taking a selfie on self-objectification. In the experiment, 107 women either took 5 selfies, unlimited selfies, had 5 photos taken of them, or had no photos taken. Participants completed an Objectified Body Consciousness Scale and 10 “I am” statements, which were coded for self-objectification. Women in the unlimited selfie condition made more appearance-based self-statements than those whose photos were not taken