Preliminary catalog of pictures taken on the lunar surface during the Apollo 15 mission

Catalog of all pictures taken from lunar module or lunar surface during Apollo 15 missio

Práticas Profissionais de Tecnologia das Construções: obras da universidade federal de Sergipe

A Construção Civil é um setor de importância na economia por seus impactos econômicos, sociais, tecnológicos e ambientais, e atualmente está em crescimento acelerado. A UFS passa por este momento de crescimento e a comunidade convive com construções e reformas. Deste modo, este estudo possibilita aos alunos de Engenharia Civil aprendizagem em canteiro de obras de técnicas construtivas, correlacionando teoria e prática, bem como a interação com a comunidade profissional e a sociedade. O método adotado consiste na elaboração de levantamentos quantitativos e orçamentos, ao consultar a realidade, com observações sistemáticas, projetos e documentos, com pesquisa documental. Os resultados mostram a aprendizagem dos alunos na prática das construções e sua interação com a sociedade. Em termos de obras públicas, comprova-se a seleção de empresas por menor preço, comprometendo a qualidade das edificações construídas. O estudo contribuiu para documentar o crescimento e a interiorização da UFS, com a participação da comunidade

Neutral Solar Wind Generated by Lunar Exospheric Dust at the Terminator

We calculate the flux of neutral solar wind observed on the lunar surface at the terminator due to solar wind protons penetrating exospheric dust grains with (1) radii greater than 0.1 microns and (2) radii greater than 0.01 microns. For grains with radii larger than 0.1 microns, the ratio of the neutral solar wind flux produced by exospheric dust to the incident ionized solar wind flux is estimated to be about 10^-4-10^-3 for solar wind speeds in excess of 800 km/s, but much lower (less than 10^-5) at average to slow solar wind speeds. However, when the smaller grain sizes are considered, this ratio is estimated to be greater than 10^-5 at all speeds, and at speeds in excess of 700 km/s reaches about 10^-3. These neutral solar wind fluxes are easily measurable with current low energy neutral atom instrumentation. Observations of neutral solar wind from the surface of the Moon would provide independent information on the distribution of very small dust grains in the lunar exosphere that would complement and constrain optical measurements at ultraviolet and visible wavelengths.Comment: in press in J. Geophys. Re

A miniature sensor for electrical field measurements in dusty planetary atmospheres

"Dusty phenomena such as regular wind-blown dust, dust storms, and dust devils are the most important, currently active, geological processes on Mars. Electric fields larger than 100 kV/m have been measured in terrestrial dusty phenomena. Theoretical calculations predict that, close to the surface, the bulk electric fields in martian dusty phenomena reach the breakdown value of the isolating properties of thin martian air of about a few 10 kV/m. The fact that martian dusty phenomena are electrically active has important implications for dust lifting and atmospheric chemistry. Electric field sensors are usually grounded and distort the electric fields in their vicinity. Grounded sensors also produce large errors when subject to ion currents or impacts from clouds of charged particles. Moreover, they are incapable of providing information about the direction of the electric field, an important quantity. Finally, typical sensors with more than 10 cm of diameter are not capable of measuring electric fields at distances as small as a few cm from the surface. Measurements this close to the surface are necessary for studies of the effects of electric fields on dust lifting. To overcome these shortcomings, we developed the miniature electric-field sensor described in this article."http://deepblue.lib.umich.edu/bitstream/2027.42/64202/1/jpconf8_142_012075.pd