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

Use of tunable nanopore blockade rates to investigate colloidal dispersions

Tunable nanopores in elastomeric membranes have been used to study the dependence of ionic current blockade rate on the concentration and electrophoretic mobility of particles in aqueous suspensions. A range of nanoparticle sizes, materials and surface functionalities has been tested. Using pressure-driven flow through a pore, the blockade rate for 100 nm carboxylated polystyrene particles was found to be linearly proportional to both transmembrane pressure (controlled between 0 and 1.8 kPa) and particle concentration (between 7 x 10^8 and 4.5 x 10^10 mL^-1). This result can be accurately modelled using Nernst-Planck transport theory. Using only an applied potential across a pore, the blockade rates for carboxylic acid and amine coated 500 nm and 200 nm silica particles were found to correspond to changes in their mobility as a function of the solution pH. Scanning electron microscopy and confocal microscopy have been used to visualise changes in the tunable nanopore geometry in three dimensions as a function of applied mechanical strain. The pores observed were conical in shape, and changes in pore size were consistent with ionic current measurements. A zone of inelastic deformation adjacent to the pore has been identified as critical in the tuning process

Formation of the Aerosol of Space Origin in Earth's Atmosphere

The problem of formation of the aerosol of space origin in Earth s atmosphere is examined. Meteoroids of the mass range of 10-18-10-8 g are considered as a source of its origin. The lower bound of the mass range is chosen according to the data presented in literature, the upper bound is determined in accordance with the theory of Whipple s micrometeorites. Basing on the classical equations of deceleration and heating for small meteor bodies we have determined the maximal temperatures of the particles, and altitudes at which they reach critically low velocities, which can be called as velocities of stopping . As a condition for the transformation of a space particle into an aerosol one we have used the condition of non-reaching melting temperature of the meteoroid. The simplified equation of deceleration without earth gravity and barometric formula for the atmosphere density are used. In the equation of heat balance the energy loss for heating is neglected. The analytical solution of the simplified equations is used for the analysis

ЕКОНОМІЧНА ЕФЕКТИВНІСТЬ БАГАТОТАРИФНОГО ОБЛІКУ ЕЛЕКТРОЕНЕРГІЇ В УКРАЇНІ

It has been established that applying a single-rate counter the consumer has not any motivation on when and what consumers of electric energy to turn overnight. In the case of multi-tariff counter, when the night is an opportunity to save money, there is some motivation. For user is enough to change the order of the day and he will get real savings to cover the cost for electricity. Thus, not only subscribers will pay less for electricity consumed at night, but also, they will contribute to leveling the load on the energy system. The application of multi-accounting in enterprises fully justified only if the technological process of manufacturing production is only at night. These bakeries, dry cleaning, laundry and more. Other companies are forced to adapt to our biological rhythms and cannot shift their power at night. In domestic use, multi-accounting has more nuances. It has been established that for the urban population the best is multiple-tariff accounting of electric energy in which exclude the possibility to pay for consumed electricity bigger than by using single tariff counters. But the economic effect of using multiple-tariff accounting of electric energy not everyone will feel the same way. The greater the volume of consumption and the most of them will be in the period between 23:00 and 07:00, the greater will be the benefit to the consumer. There has been proposed an analytical expression for determining the percentage of saving financial resources from the portion of electricity consumption at the night time periods by using multi-tariff accounting. Установлено, что при применении одно тарифных счетчиков у потребителя отсутствует какая-либо мотивация о том, когда и какие потребители электрической энергии в течение суток ему включать. В случае с двухтарифным счетчиком, когда ночью есть возможность сэкономить деньги, появляется определенная мотивация. Пользователю достаточно изменить распорядок дня, и он получит реальную экономию средств для покрытия расходов за потребленную электроэнергию. При этом абоненты будут не только платить меньше за потребленную ночью электроэнергию, но и способствовать выравниванию нагрузки на энергосистему. Применение многотарифного учета на предприятиях полностью оправдывает себя только тогда, когда технологический процесс изготовления продукции приходится исключительно на ночь. Это пекарни, химчистки, прачечные и так далее. Другие предприятия вынуждены подстраиваются под наши биологические ритмы и не могут сместить свои мощности на ночь. В быту использование многотарифного учета имеет еще больше нюансов. Установлено, что для городского населения наилучшим есть двотарифний учет электроэнергии, в котором исключена возможность платить за использованную электроэнергию больше, чем при использовании однотарифных счетчиков. Но экономический эффект от использования двохтарифного учета электроэнергии не каждый ощутит одинаково. Чем больше объёмы потребления и чем большая их часть придется на период от 23:00 до 07:00, тем большей будет выгода для потребителя.    Установлено, що для  міського населення найкращим є двотарифний облік електроенергії, у якому виключена можливість платити за спожиту електроенергію більше, ніж при використанні однотарифних лічильників. Але економічний ефект від встановлення двотарифного обліку електроенергії не кожен відчує однаково. Чим більше об’єми споживання і чим більша частка їх припаде на період з 23:00 до 07:00, тим більшою буде вигода для споживача

Proceso de diseño del Centro de Interpretación Cañadón del Duraznillo, Golfo San Jorge, Santa Cruz, Argentina

Este trabajo examina el proceso de diseño del Centro de Interpretación Cañadón del Duraznillo, ubicado en el Golfo San Jorge, Santa Cruz, Argentina. Desde los primeros esbozos morfológicos hasta la selección de materiales y detalles constructivos, dicho proceso fue guiado por simulaciones y estudios de las condiciones ambientales específicas a este caso particular, como así también recomendaciones generales apropiadas para este clima y localización geográfica a partir de bibliografía especializada y experiencias proyectuales anteriores. Los estudios desarrollados incluyeron simulaciones de asoleamiento, radiación solar, viento, iluminación natural y características térmicas de los materiales de la envolvente. El objetivo de este artículo es presentar un caso específico de arquitectura de bajo impacto ambiental y alto grado de eficiencia energética y examinar la productividad metodológica del diseño arquitectónico asistido por estudios en un laboratorio de estudios bioambientales.Fil: Kozak, Daniel Matias. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Saavedra 15. Centro de Estudios Urbanos y Regionales; ArgentinaFil: de Schiller, S.. Universidad de Buenos Aires. Facultad de Arquitectura y Urbanismo. Centro de Investigacion Habitat y Energia; ArgentinaFil: Evans, J. M.. Universidad de Buenos Aires. Facultad de Arquitectura y Urbanismo. Centro de Investigacion Habitat y Energia; ArgentinaFil: Adamo, G.. Universidad de Buenos Aires. Facultad de Arquitectura y Urbanismo. Centro de Investigacion Habitat y Energia; ArgentinaFil: Abálsamo, D.. Universidad de Buenos Aires. Facultad de Arquitectura y Urbanismo. Centro de Investigacion Habitat y Energia; Argentin