Apollo 17 EVA-1 and EVA-2 Task Decomposition: Planning for Artemis and Future Mars Missions

A decomposition of the Apollo 17 mission extravehicular activities (EVA) tasks can be used to prepare for Artemis and future Mars missions. A categorized minute by minute breakdown of the astronauts activites could be used to plan future EVAs and determine which scientific tasks or equipment may be prioritized. This is especially relevant in this critical stage for the upcoming Atemis missions and science activity planning. The infographics generated from the decomposition provide a higher level view of actual EVAs and could aid in making future EVAs more efficient and successful

Inventions and patenting in Africa: Empirical trends from 1970 to 2010

Economic development is increasingly dependent upon on utilizing new knowledge to innovate and create value, even in traditional industries and in low-income countries. This analysis uses evidence on patent families to assess innovation activity throughout sub-Saharan Africa. We find patent activity in sub-Saharan Africa-both by African inventors and by foreign inventors-is comparable to similar regions around the world, when conditioned on economic size. Patent filings in Africa have grown, particularly, since the mid-1990s, but at different rates within different African jurisdictions. Types of technologies being patented in Africa have remained stable over 30 years, with most in pharmaceuticals, chemistry, biotechnology, and engineering. The majority of patent filings in Africa are from Europe, the United States, and other high income countries. Yet, in South Africa, between 15% and 20% of patent filings are by residents of South Africa, and 3% are from other developing and emerging economies. Only a small share of inventions globally are made in sub-Saharan Africa, but for those inventions that do arise in Africa, foreign filings are made widely outside of Africa

Increased Science Instrumentation Funding Strengthens Mars Program

As the strategic knowledge gaps mature for the exploration of Mars, Mars sample return (MSR), and Phobos/Deimos missions, one approach that becomes more probable involves smaller science instrumentation and integrated science suites. Recent technological advances provide the foundation for a significant evolution of instrumentation; however, the funding support is currently too small to fully utilize these advances. We propose that an increase in funding for instrumentation development occur in the near-term so that these foundational technologies can be applied. These instruments would directly address the significant knowledge gaps for humans to Mars orbit, humans to the Martian surface, and humans to Phobos/ Deimos. They would also address the topics covered by the Decadal Survey and the Mars scientific goals, objectives, investigations and priorities as stated by the MEPAG. We argue that an increase of science instrumentation funding would be of great benefit to the Mars program as well as the potential for human exploration of the Mars system. If the total non-Earth-related planetary science instrumentation budget were increased 100% it would not add an appreciable amount to the overall NASA budget and would provide the real potential for future breakthroughs. If such an approach were implemented in the near-term, NASA would benefit greatly in terms of science knowledge of the Mars, Phobos/Deimos system, exploration risk mitigation, technology development, and public interest

Rover-Based Instrumentation and Scientific Investigations During the 2012 Analog Field Test on Mauna Kea Volcano, Hawaii

Rover-based 2012 Moon and Mars Analog Mission Activities (MMAMA) were recently completed on Mauna Kea Volcano, Hawaii. Scientific investigations, scientific input, and operational constraints were tested in the context of existing project and protocols for the field activities designed to help NASA achieve the Vision for Space Exploration [1]. Several investigations were conducted by the rover mounted instruments to determine key geophysical and geochemical properties of the site, as well as capture the geological context of the area and the samples investigated. The rover traverse and associated science investigations were conducted over a three day period on the southeast flank of the Mauna Kea Volcano, Hawaii. The test area was at an elevation of ~11,500 feet and is known as "Apollo Valley" (Fig. 1). Here we report the integration and operation of the rover-mounted instruments, as well as the scientific investigations that were conducted

Coherent phonon scattering effects on thermal transport in thin semiconductor nanowires

The thermal conductance by phonons of a quasi-one-dimensional solid with isotope or defect scattering is studied using the Landauer formalism for thermal transport. The conductance shows a crossover from localized to Ohmic behavior, just as for electrons, but the nature of this crossover is modified by delocalization of phonons at low frequency. A scalable numerical transfer-matrix technique is developed and applied to model quasi-one-dimensional systems in order to confirm simple analytic predictions. We argue that existing thermal conductivity data on semiconductor nanowires, showing an unexpected linear dependence, can be understood through a model that combines incoherent surface scattering for short-wavelength phonons with nearly ballistic long-wavelength phonons. It is also found that even when strong phonon localization effects would be observed if defects are distributed throughout the wire, localization effects are much weaker when defects are localized at the boundary, as in current experiments.Comment: 13 page

Wannier-Stark ladders in one-dimensional elastic systems

The optical analogues of Bloch oscillations and their associated Wannier-Stark ladders have been recently analyzed. In this paper we propose an elastic realization of these ladders, employing for this purpose the torsional vibrations of specially designed one-dimensional elastic systems. We have measured, for the first time, the ladder wave amplitudes, which are not directly accessible either in the quantum mechanical or optical cases. The wave amplitudes are spatially localized and coincide rather well with theoretically predicted amplitudes. The rods we analyze can be used to localize different frequencies in different parts of the elastic systems and viceversa.Comment: 10 pages, 6 figures, accepted in Phys. Rev. Let

A multi-zone model for simulating the high energy variability of TeV blazars

We present a time-dependent multi-zone code for simulating the variability of Synchrotron-Self Compton (SSC) sources. The code adopts a multi-zone pipe geometry for the emission region, appropriate for simulating emission from a standing or propagating shock in a collimated jet. Variations in the injection of relativistic electrons in the inlet propagate along the length of the pipe cooling radiatively. Our code for the first time takes into account the non-local, time-retarded nature of synchrotron self-Compton (SSC) losses that are thought to be dominant in TeV blazars. The observed synchrotron and SSC emission is followed self-consistently taking into account light travel time delays. At any given time, the emitting portion of the pipe depends on the frequency and the nature of the variation followed. Our simulation employs only one additional physical parameter relative to one-zone models, that of the pipe length and is computationally very efficient, using simplified expressions for the SSC processes. The code will be useful for observers modeling GLAST, TeV, and X-ray observations of SSC blazars.Comment: ApJ, accepte

Moessbauer/XRF MIMOS Instrumentation and Operation During the 2012 Analog Field Test on Mauna Kea Volcano, Hawaii

Field testing and scientific investigations were conducted on the Mauna Kea Volcano, Hawaii, as part of the 2012 Moon and Mars Analog Mission Activities (MMAMA). Measurements were conducted using both stand-alone and rover-mounted instruments to determine the geophysical and geochemical properties of the field site, as well as provide operational constraints and science considerations for future robotic and human missions [1]. Reported here are the results from the two MIMOS instruments deployed as part of this planetary analog field test

Quantum chaos in nanoelectromechanical systems

We present a theoretical study of the electron-phonon coupling in suspended nanoelectromechanical systems (NEMS) and investigate the resulting quantum chaotic behavior. The phonons are associated with the vibrational modes of a suspended rectangular dielectric plate, with free or clamped boundary conditions, whereas the electrons are confined to a large quantum dot (QD) on the plate's surface. The deformation potential and piezoelectric interactions are considered. By performing standard energy-level statistics we demonstrate that the spectral fluctuations exhibit the same distributions as those of the Gaussian Orthogonal Ensemble (GOE) or the Gaussian Unitary Ensemble (GUE), therefore evidencing the emergence of quantum chaos. That is verified for a large range of material and geometry parameters. In particular, the GUE statistics occurs only in the case of a circular QD. It represents an anomalous phenomenon, previously reported for just a small number of systems, since the problem is time-reversal invariant. The obtained results are explained through a detailed analysis of the Hamiltonian matrix structure.Comment: 14 pages, two column