High-Magnification Long-Working Distance Plenoptic Background Oriented Schlieren (BOS).
Abstract not provided.
Guildenbecher, Daniel Robert↗
SEARCH · Engineering Papers
Results for “BOS”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Impact of Balance Of System (BOS) costs on photovoltaic power systems
The Department of Energy has developed a program to effect a large reduction in the price of photovoltaic modules, with significant progress already achieved toward the 1986 goal of 50 cents/watt (1975 dollars). Remaining elements of a P/V power system (structure, battery storage, regulation, control, and wiring) are also significant cost items. The costs of these remaining elements are commonly referred to as Balance-of-System (BOS) costs. The BOS costs are less well defined and documented than module costs. The Lewis Research Center (LeRC) in 1976/77 and with two village power experiments that will be installed in 1978. The costs were divided into five categories and analyzed. A regression analysis was performed to determine correlations of BOS Costs per peak watt, with power size for these photovoltaic systems. The statistical relationship may be used for flat-plate, DC systems ranging from 100 to 4,000 peak watts. A survey of suppliers was conducted for comparison with the predicted BOS cost relationship.
Hein, G. F.↗
Materials Data on Th(BOs)2 by Materials Project
Th(BOs)2 crystallizes in the tetragonal P4_2/n space group. The structure is zero-dimensional and consists of four thorium molecules and eight BOs clusters. In each BOs cluster, Os2- is bonded in a single-bond geometry to one B atom. The Os–B bond length is 1.78 Å. B is bonded in a single-bond geometry to one Os2- atom.
36 MATERIALS SCIENCE↗
Does geography matter? A study of technological learning and innovation in the U.S. Solar photovoltaic balance-of-systems (PV BOS) industry
Different learning channels (i.e., learning from upstream actors, local network, global codified knowledge, etc.) coexist in firms’ technological innovation processes. Although firms are exposed to globalization and convenient communication and transportation tools, researchers still argue about the role of geography in technology innovation. Geographic proximity can facilitate knowledge spillover and network-building. Localized learning and the significance of geography indicate the importance of local knowledge in innovative activities. Local knowledge tends to be more closely aligned with local firms’ technological demand and easier to understand and absorb, because they are created and applied in the same context. However, following Schumpeter, innovation researchers believe that diverse knowledge, especially knowledge from external industries and geographically distant places, is a valuable source for innovation, especially disruptive innovation. Therefore, firms must balance different learning channels, especially between localized learning and global learning. However, it is still unclear about the extent to which localized learning is important for technology innovations and which factors influence the degree of localized learning. Meanwhile, most studies in the area of localized learning usually take no account of the international dimension and the interdependent of knowledge at different geographic scales. Different learning channels (i.e., learning from upstream actors, local network, global codified knowledge, etc.) coexist in firms’ technological innovation processes. Although firms are exposed to globalization and convenient communication and transportation tools, researchers still argue about the role of geography in technology innovation. Geographic proximity can facilitate knowledge spillover and network-building. Localized learning and the significance of geography indicate the importance of local knowledge in innovative activities. Local knowledge tends to be more closely aligned with local firms’ technological demand and easier to understand and absorb, because they are created and applied in the same context. However, following Schumpeter, innovation researchers believe that diverse knowledge, especially knowledge from external industries and geographically distant places, is a valuable source for innovation, especially disruptive innovation. Therefore, firms must balance different learning channels, especially between localized learning and global learning. However, it is still unclear about the extent to which localized learning is important for technology innovations and which factors influence the degree of localized learning. Meanwhile, most studies in the area of localized learning usually take no account of the international dimension and the interdependent of knowledge at different geographic scales. To address this research gap, this paper empirically investigated firms’ learning and innovation processes in relation to the geography. The aim is to answer the following three questions: 1) how does geographic distance influence knowledge spillover; 2) how technological characteristics influence knowledge acquisition choices as regards local vs. non-local knowledge? and 3) how do local and non-local knowledge affect the quality of innovation? The subject of our empirical inquiry is photovoltaic balance-of-systems (PV BOS) components. This choice is primarily motivated by two factors: (1) large-scale deployment of distributed solar PV technologies is widely considered to be an important piece in addressing the environmental impacts of the electricity sector, making PV an important technology to study; furthermore, there is a general consensus that the biggest barrier for a wider deployment of PV is the high price of non-module components, and (2) technological aspects of non-module components of PV systems make local conditions (climate, regulation, learning networks, etc.) salient, thus affording a rich empirical setting to explore the geography-innovation-economy interactions at the local level. We find that the localization effect of technological learning in the solar PV BOS industry is at state level, the number of citations-based linkages decreases with distance, and we also find that international knowledge significantly contributes to the quality of patents, which suggests that state border might be a barrier of current knowledge spillover, and only focusing on local innovation networks is not sufficient for promoting PV BOS innovation.
29 ENERGY PLANNING, POLICY, AND ECONOMY↗
Dot tracking methodology for background-oriented schlieren (BOS)
We propose here a dot tracking methodology for processing background-oriented schlieren (BOS) images. The technique improves the accuracy, precision and spatial resolution compared to conventional cross-correlation algorithms. Our methodology utilizes the prior information about the dot pattern such as the location, size and number of dots to provide near 100% yield even for high dot densities (20 dots/32 × 32 pixels) and is robust to image noise. Furthermore, we propose an improvement to the displacement estimation step in the tracking process, especially for noisy images, using a “correlation correction”, whereby we combine the spatial resolution benefit of the tracking method and the smoothing property of the correlation method to increase the dynamic range of the overall measurement process. We evaluate the performance of the method with synthetic BOS images of buoyancy-driven turbulence rendered using ray-tracing simulations, and experimental images of flow in the exit plane of a converging–diverging nozzle. The results show that the improved spatial resolution results in a better accuracy of the tracking method compared to correlation-based methods in regions with sharp displacement gradients, and the correlation correction step reduces the noise floor of the measurement, resulting in a fourfold improvement in the dynamic range.
42 ENGINEERING↗
Visualization of Flow Separation Around an Atmospheric Entry Capsule at Low-Subsonic Mach Number Using Background-Oriented Schlieren (BOS)
This paper presents the results of visualization of separated flow around a generic entry capsule that resembles the Apollo Command Module (CM) and the Orion Multi-Purpose Crew Vehicle (MPCV). The model was tested at flow speeds up to Mach 0.4 at a single angle of attack of 28 degrees. For manned spacecraft using capsule-shaped vehicles, certain flight operations such as emergency abort maneuvers soon after launch and flight just prior to parachute deployment during the final stages of entry, the command module may fly at low Mach number. Under these flow conditions, the separated flow generated from the heat-shield surface on both windward and leeward sides of the capsule dominates the wake flow downstream of the capsule. In this paper, flow visualization of the separated flow was conducted using the background-oriented schlieren (BOS) method, which has the capability of visualizing significantly separated wake flows without the particle seeding required by other techniques. Experimental results herein show that BOS has detection capability of density changes on the order of 10(sup-5).
Mizukaki, Toshiharu↗
Background Oriented Schlieren (BOS) and other Flow Visualization Developments and Applications at GRC
This is a presentation to be given at an internal NASA Advanced Schlieren Working Group Meeting. The presentation will cover the recent developments and applications of flow visualization methods at GRC. The topics being discussed will include the use of Background Oriented Schlieren (BOS) in the study of screech and its associated shock spacing as well as in the investigation of broadband shock noise reduction in the Jet-Surface Interaction Tests. In addition, other flow visualiztion methods will be discussed in an on-going study comparing schlieren, shadowgraph, BOS, and focusing schlieren.
background oriented schlieren↗
Materials Data on BOs by Materials Project
BOs is Tungsten Carbide structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Os3+ is bonded to six equivalent B3- atoms to form a mixture of distorted corner, edge, and face-sharing OsB6 pentagonal pyramids. All Os–B bond lengths are 2.21 Å. B3- is bonded to six equivalent Os3+ atoms to form a mixture of distorted corner, edge, and face-sharing BOs6 pentagonal pyramids.
36 MATERIALS SCIENCE↗
HybridBOSSE (Hybrid Balance-of-System (BOS) Systems Engineering Model)
Hybrid Power Plants (HPPs) have the potential to increase the value of renewable energy systems and decrease their costs through shared development (e.g., permitting) and infrastructure (e.g., collection system). Prior work has identified potential cost savings and technical and economic performance improvements for solar plus storage plants. However, additional research is needed to understand cost drivers that are specific to hybrid wind plants. Here we analyze the potential for shared infrastructure cost savings at one type of hybrid plant: wind plus solar photovoltaic (PV). To perform this analysis, we developed a new open-source, Python-based cost modeling tool: the Hybrid Balance-of-System (BOS) Systems Engineering model (HybridBOSSE). HybridBOSSE is an extension of NREL's LandBOSSE tool.
Barker, Aaron↗
OffshoreBOS (Offshore Wind Balance-of-Station (BOS) Model) "S" was originally "System" [SWR-16-27]
+++ This repository was archived by the owner on May 4, 2020. It is now read-only. +++ An offshore balance of station (BOS) model for estimating the costs in assembly, installation, financing, and decommissioning of offshore wind plants.
Maness, Michael↗
Background Oriented Schlieren (BOS) of a Supersonic Aircraft in Flight
This presentation describes the development and use of Background Oriented Schlieren (BOS) on a full-scale supersonic jet in flight. A series of flight tests was performed in October 2014 and February 2015 using the flora of the desert floor in the Supersonic Flight Corridor on the Edwards Air Force Base as a background. Flight planning was designed based on the camera resolution, the mean size and color of the predominant plants, and the navigation and coordination of two aircraft. Software used to process the image data was improved with additional utilities. The planning proved to be effective and the vast majority of the passes of the target aircraft were successfully recorded. Results were obtained that are the most detailed schlieren imagery of an aircraft in flight to date.
Visualization↗
Materials Data on Nd(BOs)4 by Materials Project
Nd(OsB)4 is alpha Pu-derived structured and crystallizes in the tetragonal P4_2/n space group. The structure is three-dimensional. Nd2+ is bonded in a 8-coordinate geometry to eight equivalent Os2- atoms. There are four shorter (3.22 Å) and four longer (3.23 Å) Nd–Os bond lengths. Os2- is bonded in a 4-coordinate geometry to two equivalent Nd2+ and four equivalent B+1.50+ atoms. There are a spread of Os–B bond distances ranging from 2.14–2.19 Å. B+1.50+ is bonded in a 4-coordinate geometry to four equivalent Os2- atoms.
36 MATERIALS SCIENCE↗
Materials Data on Pr(BOs)2 by Materials Project
Pr(OsB)2 crystallizes in the orthorhombic Fddd space group. The structure is three-dimensional. Pr3+ is bonded in a 4-coordinate geometry to four equivalent Os+1.50- atoms. All Pr–Os bond lengths are 3.06 Å. Os+1.50- is bonded in a 4-coordinate geometry to two equivalent Pr3+ and four equivalent B atoms. There are two shorter (2.10 Å) and two longer (2.18 Å) Os–B bond lengths. B is bonded to four equivalent Os+1.50- atoms to form a mixture of distorted corner and edge-sharing BOs4 trigonal pyramids.
36 MATERIALS SCIENCE↗
Materials Data on Sm(BOs)2 by Materials Project
Sm(OsB)2 crystallizes in the orthorhombic Fddd space group. The structure is three-dimensional. Sm3+ is bonded in a 4-coordinate geometry to four equivalent Os+1.50- atoms. All Sm–Os bond lengths are 3.03 Å. Os+1.50- is bonded in a 4-coordinate geometry to two equivalent Sm3+ and four equivalent B atoms. There are two shorter (2.09 Å) and two longer (2.18 Å) Os–B bond lengths. B is bonded in a 4-coordinate geometry to four equivalent Os+1.50- atoms.
36 MATERIALS SCIENCE↗
Materials Data on Sm(BOs)4 by Materials Project
Sm(OsB)4 is alpha Pu-derived structured and crystallizes in the tetragonal P4_2/n space group. The structure is three-dimensional. Sm2+ is bonded in a 8-coordinate geometry to eight equivalent Os2- atoms. There are four shorter (3.21 Å) and four longer (3.22 Å) Sm–Os bond lengths. Os2- is bonded in a 4-coordinate geometry to two equivalent Sm2+ and four equivalent B+1.50+ atoms. There are a spread of Os–B bond distances ranging from 2.14–2.18 Å. B+1.50+ is bonded in a 4-coordinate geometry to four equivalent Os2- atoms.
36 MATERIALS SCIENCE↗
Materials Data on Ce(BOs)2 by Materials Project
CeOs2B2 crystallizes in the orthorhombic Fddd space group. The structure is three-dimensional. Ce3+ is bonded in a 4-coordinate geometry to four equivalent Os+1.50- atoms. All Ce–Os bond lengths are 3.01 Å. Os+1.50- is bonded in a 4-coordinate geometry to two equivalent Ce3+ and four equivalent B atoms. There are two shorter (2.09 Å) and two longer (2.17 Å) Os–B bond lengths. B is bonded in a 4-coordinate geometry to four equivalent Os+1.50- atoms.
36 MATERIALS SCIENCE↗
Materials Data on Ce(BOs)4 by Materials Project
CeOs4B4 crystallizes in the tetragonal P4_2/n space group. The structure is three-dimensional. Ce3+ is bonded in a 8-coordinate geometry to eight equivalent Os+0.75- atoms. There are four shorter (3.20 Å) and four longer (3.22 Å) Ce–Os bond lengths. Os+0.75- is bonded in a 4-coordinate geometry to two equivalent Ce3+ and four equivalent B atoms. There are a spread of Os–B bond distances ranging from 2.13–2.19 Å. B is bonded in a 5-coordinate geometry to four equivalent Os+0.75- and one B atom. The B–B bond length is 1.79 Å.
36 MATERIALS SCIENCE↗
Materials Data on La(BOs)2 by Materials Project
La(OsB)2 crystallizes in the orthorhombic Fddd space group. The structure is three-dimensional. La3+ is bonded in a 4-coordinate geometry to four equivalent Os+1.50- atoms. All La–Os bond lengths are 3.06 Å. Os+1.50- is bonded in a 4-coordinate geometry to two equivalent La3+ and four equivalent B atoms. There are two shorter (2.11 Å) and two longer (2.18 Å) Os–B bond lengths. B is bonded to four equivalent Os+1.50- atoms to form a mixture of distorted edge and corner-sharing BOs4 trigonal pyramids.
36 MATERIALS SCIENCE↗