874 resultados para Moon landing


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Among the Solar System’s bodies, Moon, Mercury and Mars are at present, or have been in the recent years, object of space missions aimed, among other topics, also at improving our knowledge about surface composition. Between the techniques to detect planet’s mineralogical composition, both from remote and close range platforms, visible and near-infrared reflectance (VNIR) spectroscopy is a powerful tool, because crystal field absorption bands are related to particular transitional metals in well-defined crystal structures, e.g., Fe2+ in M1 and M2 sites of olivine or pyroxene (Burns, 1993). Thanks to the improvements in the spectrometers onboard the recent missions, a more detailed interpretation of the planetary surfaces can now be delineated. However, quantitative interpretation of planetary surface mineralogy could not always be a simple task. In fact, several factors such as the mineral chemistry, the presence of different minerals that absorb in a narrow spectral range, the regolith with a variable particle size range, the space weathering, the atmosphere composition etc., act in unpredictable ways on the reflectance spectra on a planetary surface (Serventi et al., 2014). One method for the interpretation of reflectance spectra of unknown materials involves the study of a number of spectra acquired in the laboratory under different conditions, such as different mineral abundances or different particle sizes, in order to derive empirical trends. This is the methodology that has been followed in this PhD thesis: the single factors previously listed have been analyzed, creating, in the laboratory, a set of terrestrial analogues with well-defined composition and size. The aim of this work is to provide new tools and criteria to improve the knowledge of the composition of planetary surfaces. In particular, mixtures composed with different content and chemistry of plagioclase and mafic minerals have been spectroscopically analyzed at different particle sizes and with different mineral relative percentages. The reflectance spectra of each mixture have been analyzed both qualitatively (using the software ORIGIN®) and quantitatively applying the Modified Gaussian Model (MGM, Sunshine et al., 1990) algorithm. In particular, the spectral parameter variations of each absorption band have been evaluated versus the volumetric FeO% content in the PL phase and versus the PL modal abundance. This delineated calibration curves of composition vs. spectral parameters and allow implementation of spectral libraries. Furthermore, the trends derived from terrestrial analogues here analyzed and from analogues in the literature have been applied for the interpretation of hyperspectral images of both plagioclase-rich (Moon) and plagioclase-poor (Mars) bodies.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In his last two State of the Union addresses, President Barack Obama has focused on the need to deliver innovative solutions to improve human health, through the Precision Medicine Initiative in 2015 and the recently announced Cancer Moonshot in 2016. Precision cancer care has delivered clear patient benefit, but even for high-impact medicines such as imatinib mesylate (Glivec) in chronic myeloid leukaemia, the excitement at the success of this practice-changing clinical intervention has been somewhat tempered by the escalating price of this 'poster child' for precision cancer medicine (PCM). Recent studies on the costs of cancer drugs have revealed significant price differentials, which are a major causative factor behind disparities in the access to new generations of immunological and molecularly targeted agents. In this perspective, we will discuss the benefits of PCM to modern cancer control, but also emphasise how increasing costs are rendering the current approaches to integrating the paradigm of PCM unsustainable. Despite the ever increasing pressure on cancer and health care budgets, innovation will and must continue. Value-based frameworks offer one of the most rational approaches for policymakers committed to improving cancer outcomes through a public health approach.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The study was done at Kayinja landing site, one of the six gazzeted landing sites located on the eastern side of Lake George, Kamwenge district to investigate illegal fishing practices on the lake. The objectives of the study were to identify the fish species most affected by illegal fishing, factors that drive illegal fishing on the lake, impact of illegal fishing to the fishery and livelihoods of the communities around the lake and to find out the prospect of ending illegal fishing on the lake. A participatory approach was used during the study where fishers and fisheries staff were interviewed for the fish species targeted, current management approach so as to find out species at risk and anticipate the prospect or ending illegal fishing respectively also past records of the daily catch ror a period of five years were used to study the trend henee ascertain the impact of illegal fishing to the fishery and livelihoods of the communities around. Results indicated that the most targeted fish hence other wise affected by illegal fishing is Oreochromis niloticus, the most immediate impact being a decline in fish stocks, whereas defining mechanisms to increase fish stocks through closed seasons and implementation of minimum mesh size policy being the prospect to end illegal fishing on the lake.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Title provided by cataloger.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A radical change took place in Mexican narratives of belonging during the 1990s, when NAFTA was first negotiated. Narratives of migration drastically changed the status of Mexican migrants to the US, formerly derided as ‘pochos’, presenting them as model citizens instead. Following Derrida, I argue the role of the migrant became that of a supplement, which is, discursively, at the same time external to and part of a given unit, standing for and allowing deeper transformations to take place in the whole discourse of bilateral relations and national identity more generally. I use Derrida’s concept of the supplement to discuss changing representations of Chicanos in Mexican cinema, and to assess the extent that they have succeeded in reframing the discourse on national identity, with a focus on gender.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A bimonthly literary magazine edited by Zhou Shoujuan 周瘦鵑, featuring fiction, topical articles, and entertainment features, published from September 1921 through November 1925.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A bimonthly literary magazine edited by Zhou Shoujuan 周瘦鵑, featuring fiction, topical articles, and entertainment features, published from September 1921 through November 1925.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A bimonthly literary magazine edited by Zhou Shoujuan 周瘦鵑, featuring fiction, topical articles, and entertainment features, published from September 1921 through November 1925.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A bimonthly literary magazine edited by Zhou Shoujuan 周瘦鵑, featuring fiction, topical articles, and entertainment features, published from September 1921 through November 1925.