The Maunakea Spectroscopic Explorer Book 2018

(Abridged) This is the Maunakea Spectroscopic Explorer 2018 book. It is intended as a concise reference guide to all aspects of the scientific and technical design of MSE, for the international astronomy and engineering communities, and related agencies. The current version is a status report of MSE's science goals and their practical implementation, following the System Conceptual Design Review, held in January 2018. MSE is a planned 10-m class, wide-field, optical and near-infrared facility, designed to enable transformative science, while filling a critical missing gap in the emerging international network of large-scale astronomical facilities. MSE is completely dedicated to multi-object spectroscopy of samples of between thousands and millions of astrophysical objects. It will lead the world in this arena, due to its unique design capabilities: it will boast a large (11.25 m) aperture and wide (1.52 sq. degree) field of view; it will have the capabilities to observe at a wide range of spectral resolutions, from R2500 to R40,000, with massive multiplexing (4332 spectra per exposure, with all spectral resolutions available at all times), and an on-target observing efficiency of more than 80%. MSE will unveil the composition and dynamics of the faint Universe and is designed to excel at precision studies of faint astrophysical phenomena. It will also provide critical follow-up for multi-wavelength imaging surveys, such as those of the Large Synoptic Survey Telescope, Gaia, Euclid, the Wide Field Infrared Survey Telescope, the Square Kilometre Array, and the Next Generation Very Large Array.Comment: 5 chapters, 160 pages, 107 figure

Novel micron- and nano-scale energetic materials for advanced gun propulsion, their material properties, and their effects on ballistic performance

This dissertation focused on the investigation of novel materials that are both energetic and inert in their micron- and nano-scale crystalline form. The characterization of the materials properties and its effects on the ballistic performance when incorporated into a composite material were evaluated as a gun propellant for application in a future weapon system for the US Army. Some of these materials may find dual use in civilian applications. Applications in small and medium arms, artillery, tank, aircraft, and shipboard gun systems will all benefit from these advancements. Not only will gun system performance be improved for greater stand-off range and accuracy, but the ability to perform consistently across a broad temperature range. Additionally, an improved performance and longer gun barrel life achievable by tailoring the combustion products, lowering the propellant flame temperature, minimum sensitivity of burning velocity to pressure, temperature and gas velocity (erosive burning) and with munitions that are insensitive to outside stimulus attack will give such systems a significant advantage during military use. In addition, green chemistry and lower lifecycle cost were taken into consideration during this research. The approach to be taken was to incorporate these novel materials into a gun propellant formulation by using nitramine-based micron scale cyclotrimethylene trinitramine (RDX) explosives in combination with synthesized novel ingredients in nanoscale crystalline form, characterize the material properties and predict the ballistic performance across the ballistic temperature range. The nano-scale crystalline materials evaluated consisted of polymeric nitrogen stabilized in single wall carbon nanotubes (SWNTs), nitrogenated boron nanotubes / nanofibers (BNNTs/BNNFs), nano-aluminum, and titanium dioxide. The polymeric nitrogen and the nitrogenated boron nanotubes / nanofibers (BNNTs/BNNFs), should provide an enhancement in the propellant burn rate by achieving the burn rate differential goal of 3:1 between the fast and the slow burning propellant and at the same time improve the gun propellant performance by lowering the CO/CO2 ratio and raising the N2 / CO ratio for mitigating gun bore wear and erosion, respectively. For the synthesis approaches of polymeric nitrogen stabilized in carbon nanotubes, the following synthesis method were performed, optimized and compared: Electrochemical Reactions, Microwave Induced Electrochemical Chemical Reactions and Plasma Enhanced Chemical Vapor Deposition (PE-CVD). The Electrochemical Reaction process has proven to be the most efficient synthesis approach for the polymeric nitrogen based on analytical results obtained through Raman Spectroscopy, Laser Ablation Mass Spectroscopy, Scanning Electron Microscope, Fourier Transform Infrared-Attenuated Total Reflectance (FTIR-ATR) and Differential Scanning Calorimeter/Thermal Gravimetric Analysis (DSC/TGA). The PE-CVD is the second recommended synthesis approach to synthesize the polymeric nitrogen although a cost benefit economic analysis has to be performed which is beyond the objectives of this research work. For the synthesis of the nitrogenated boron nanotubes, the use of the magnesium borohydride to initiate the reaction has proven to be the most optimized process due to a much lower reaction temperature which is approximately 500°C when compared with the reaction temperature of 950°C when using Magnesium Boride (MgB2) in the thermally induced CVD process. The small scale synthesis of boron nanotubes /nanofibers carried out using MgB2 powder, Nickel Boride (Ni2B) powder catalysts and mesostructured hexagonal framework zeolite powder was successfully achieved at 950C. The quality of the nanotubes produced was checked by Raman spectroscopy and transmission electron microscope analysis. The TEM data shows the production of 10-20 nm boron nanotubes using the MgB2, Ni2B and Mobile Crystalline Material (MCM-41) in the synthesis process

Structure determination of membrane proteins by electron crystallography

A fundamental principle of life is the separation of environments into different compartments. Prokaryotes shield their interior from the environment by a plasma membrane and in some cases also by a cell wall. Eukaryotes refine this compartmentalization by building different organelles for different parts of the cell metabolism. Nevertheless, these different compartments are dependent on each other and are interconnected by membrane proteins that transport specific nutrients, hormones, ions, water and waste products across the membrane and facilitate signal transmission between different compartments. Understanding the structure and function of membrane proteins can therefore allow an enormous insight into the regulation of different metabolic pathways. The electron microscope (EM) proved itself a great tool for studying membrane proteins, offering the unique opportunity to image membrane proteins within a lipid bilayer as close to the natural conditions as possible. Processing of images acquired by an electron microscope poses a challenging task for both scientist and processing hardware. Newly developed and optimized algorithms are needed to improve the image processing to a level that allows atomic resolution to be achieved regularly. Membrane proteins pose a difficult challenge for a structural biologist. To crystallize membrane proteins into well ordered two dimensional (2D) or three dimensional (3D) crystals is one of the most important prerequisites for structural analysis at the atomic level, yet membrane proteins are notoriously difficult to crystallize. One exception may be bacteriorhodopsin, which forms near-perfect crystals already in its native membrane. This may explain the fact that the first 2D electron crystallographic structure determined at 7 Å resolution by Henderson and Unwin[20][43] in 1975 was the structure of bacteriorhodopsin. In 1990 the structure of Br was determined to atomic resolution by Henderson et al.[19], being the first atomic structure of a membrane protein. The structure determination of Br was also the starting point for the mrc program suite, which is widely used at the moment in the, albeit small, 2D electron crystallography community. Using the mrc software Kühlbrandt et al.[26] solved the structure of the light-harvesting chlorophyll a/b-protein complex in 1994. For recording the images they used the spot scan technique developed by Downing in 1991[9]. The first aquaporin water channel determined was aquaporin 1, resolved by Walz et al. in 1997[45] at 6 Å resolution, and subsequently solved to atomic resolution by Murata et al. in 2000[29]. Recently, several more aquaporin structures were determined by 2D electron crystallographic methods, aquaporin-0 (AQP0) by Gonen et al. in 2004[14] at 3 Å and in 2005[13] at 1.9 Å and aquaporin-4 (AQP4) by Hiroaki et al. in 2006[22]. Interestingly, AQP4 shows exactly the same monomer arrangement as SoPIP2;1. The recent publications show that the trend goes from recording solely images to the recording of diffraction data in combination with images or even to recording diffraction data exclusively, and then using methods developed for x-ray crystallography to obtain the phase information. Given the fact that the software available for processing of 2D electron diffraction patterns is less evolved than the one for processing images, and given this new development of increased usage of diffraction patterns, it only makes sense to focus on implementing new and improved programs for 2D electron diffraction processing. In this work I would like to present the advances I achieved in the structural determination of aquaporin 2, as well as my contribution to other projects, in particular the structural investigations of SoPIP2;1 and KdgM. I will also explain the modified sample preparation methods which made data recording at high tilt angles more reliable and achieved an improvement in resolution of the measured data. A second, equally important and detailed part of my thesis is the work invested in improving and extending the image processing to a point where a user, not adept in programming in several languages, can use it and produce good results. For this I improved the functionality and performance at several points, including a strong emphasis on user friendliness and ease of maintenance

Volume 4, Chapter 8-3: Tropics: Epiphyte Ecology, Part 1

https://digitalcommons.mtu.edu/bryo-ecol-subchapters/1206/thumbnail.jp

Technology for large space systems: A bibliography with indexes (supplement 17)

This bibliography lists 512 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1987 and June 30, 1987. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems

Wrinkling behaviour of biaxial non-crimp fabrics during preforming

The necessary lightweighting of the transport sector to meet emission reduction targets can be helped through the expanded use of composites. However, for the high volume production of composites to be cost-effective, it is needed that they can be manufactured through automated liquid composite moulding (LCM). Furthermore, the defects that occur during the initial preforming stage of LCM, notably wrinkles, are a key obstacle preventing automation and adoption of LCM, because wrinkles significantly compromise the component performance, and because there is currently no reliable method for mitigating them. To pave the way towards wrinkling mitigation during preforming, this thesis aims to characterise the wrinkling behaviour of non-crimp fabrics (NCFs) as well as to investigate how the wrinkling severity is affected by the tool geometry. These aims are achieved through both experimental and numerical approaches. Firstly, experimental forming tests are conducted to characterise the mechanisms, severity and variability of wrinkling for a ±45° biaxial NCF during preforming, considering four contrasting benchmark geometries. Secondly, a large dataset of forming simulations for various tool geometries is generated and used to investigate the effect of geometry on wrinkling severity, and to develop a deep learning based surrogate model for rapidly predicting the fabric wrinkling over a given tool geometry. The results demonstrate that two macroscale wrinkling mechanisms exist for this NCF and that the most severe wrinkles occur consistently via lateral fabric compression during material draw-in rather than tow compression at shear-lockup. Furthermore, they show that the wrinkling variability is significant and is especially apparent for multi-layer forming. Additionally, the tool geometry is shown to have a substantial effect on wrinkling with more tapered geometries leading to less severe wrinkling. Lastly, the surrogate model is demonstrated to achieve similar predictions to the finite element simulations but at a much lower computational cost, thus enabling the optimisation of component geometry for minimal wrinkling

Functionalization of nanomaterials by atomic layer deposition

126 p.La deposición de capas atómicas o ¿Atomic Layer Deposition¿ (ALD) es unatécnica sencilla pero poderosa para el recubrimiento y la modificación de losnanomateriales. El proceso se basa en la reacción sólido-gas, en la cual losprecursores se introducen por separado en fase gaseosa y reaccionan con la superficiesólida. La introducción de los precursores por fases o ciclos, lleva finalmente, alcrecimiento controlado del material deseado. Este mecanismo de trabajo especial,presenta ventajas prometedores como la alta precisión del espesor, el crecimiento nodireccional y la alta uniformidad en comparación con otros métodos de recubrimientocomo la Deposición Química de Vapor o CVD (de sus siglas en inglés ChemicalVapor Deposition). Ocasionalmente se suele llevar a cabo un proceso de ALDmodificado, llamado infiltración en fase vapor, en el que se introduce y se infiltra unprecursor metálico en materiales blandos. Esto a menudo produce interesantesalteraciones en las propiedades intrínsecas de los materiales, incluyendo laspropiedades eléctricas, mecánicas, ópticas, etc. Tanto el recubrimiento como lainfiltración a través del ALD son cada vez más interesantes para la ciencia de losmateriales. Esta tesis estudia desde los aspectos fundamentales del mecanismo dereacción entre los precursores y los grupos funcionales en el ALD, hasta elcrecimiento de nanopartículas y la fabricación de nanoestructuras a través del ALD.En la primera parte de esta tesis, se presenta un método sintético para fabricardistintas nanoestructuras basados en ZnO incluyendo nanopartículas 0D, nanotubos1D y nanoláminas 2D a través de ALD y de la elección de diferentes plantillas. Porejemplo, moléculas hidrófobas e hidrófilas son auto-ensambladas como plantillas. Lasnanopartículas de ZnO se sintetizan en las zonas hidrófilas de la superficie medianteALD. Usando nanofibras electrohiladas o nanocubos de NaCl como plantilla, seobtienen nanotubos de ZnO 1D y nanoláminas 2D de ZnO por medio del crecimientode ZnO con ALD y la posterior eliminación de la plantilla. Esta ruta sintética usandoel ALD ofrece nuevas posibilidades para la síntesis sencilla de nanoestructuras, convarias aplicaciones potenciales.CIC NanoGUN

Topographic Influences on Trends and Cycles in Nutrient Export from Forested Catchments on the Precambrian Shield

This dissertation explored topographic controls on spatial and temporal patterns in water yield and nutrient (carbon, nitrogen and phosphorus) export from forested headwater catchments in the Turkey Lakes Watershed in central Ontario, where other factors contributing to differences in water yield and nutrient export, including climate, geology, forest, and soils, are relatively constant. Topographic characteristics, including (a) hydrological flushing potential (expansion of water table into nitrate-N producing areas); (b) hydrological storage potential (area of wetlands, which can alternatively allow water and nutrients to bypass wetlands when storage capacity is filled with water or to trap them when not filled); and (c) hydrological loading potential (differences in precipitation caused by elevation), were considered in deconstructing non-stationary (linear trends) and stationary (oscillating cycles) patterns in water yield and nutrient export data. Topography explained the majority of differences in water yield and nutrient export. For spatial variation, topographic metrics representing hydrologic flushing potential predicted the majority of the spatial variation in nitrate-N export. In contrast, topographic metrics representing hydrologic storage potential explained the majority of the observed spatial variation in dissolved organic carbon, dissolved organic nitrogen and total dissolved phosphorus export. For temporal variation, catchments with low hydrologic loading potential were generally more sensitive to trends and cycles for water and nutrient export. Among these catchments, hydrological storage potential had no significant effect on water export trends, but had a significant effect on water export cycles; namely, the water export range was larger in the catchments with higher hydrological storage potential, even though the water export average was the same as catchments with lower hydrological storage potential. For nutrient export, the non-stationary signals were not consistent among the nutrients, but the amplitude of stationary signals in nutrient export in catchments with high hydrological storage potential compared to those with low hydrological storage potential was higher for organic nutrients and lower for nitrate-nitrogen. Despite many similarities in these headwater catchments, topography influenced the absolute and relative magnitude of hydrological and biogeochemical export from these catchments, which will have implications on the productivity and biodiversity of downstream aquatic systems

Proceedings of the NASA Conference on Space Telerobotics, volume 4

Papers presented at the NASA Conference on Space Telerobotics are compiled. The theme of the conference was man-machine collaboration in space. The conference provided a forum for researchers and engineers to exchange ideas on the research and development required for the application of telerobotic technology to the space systems planned for the 1990's and beyond. Volume 4 contains papers related to the following subject areas: manipulator control; telemanipulation; flight experiments (systems and simulators); sensor-based planning; robot kinematics, dynamics, and control; robot task planning and assembly; and research activities at the NASA Langley Research Center