11,358 research outputs found
Technique for abrasive cutting of thick-film conductors for hybrid circuits
Abrasive jet technique, producing prototype conductor networks for thick-film hybrid microcircuits, does not require screening and fixing procedures. Pantograph engraver is used to perform abrasive cutting of the conductor network
Flight-measured inlet pressure transients accompanying engine compressor surges on the F-111A airplane
Two-F-111A airplanes were subjected to conditions that caused engine compressor surges and accompanying duct hammershock pressure transients. Flight speed ranged from Mach 0.71 to Mach 2.23, and altitude varied from approximately 3200 meters to 14,500 meters. A wide range of compressor pressure ratios was covered. Stabilized free-stream, engine, and duct conditions were established before each compressor surge. Dynamic pressure instrumentation at the compressor face and in the duct recorded the pressure transients associated with the surges. Hammershock pressures were analyzed with respect to the stabilized conditions preceding the compressor surges. The hammershock transients caused large pressure rises at the compressor face and in the duct. Hammershock pressure ratios at the compressor face were not affected by free-stream Mach number or altitude but were functions of engine variables, such as compressor pressure ratio. The maximum hammershock pressure ratio of approximately 1.83 occurred at a compressor pressure ratio of approximately 21.7
Prosecuting Dark Net Drug Marketplace Operators Under the Federal Crack House Statute
Over 70,000 Americans died as the result of a drug overdose in 2017, a record year following a record year. Amidst this crisis, the popularity of drug marketplaces on what has been called the “dark net” has exploded. Illicit substances are sold freely on such marketplaces, and the anonymity these marketplaces provide has proved troublesome for law enforcement. Law enforcement has responded by taking down several of these marketplaces and prosecuting their creators, such as Ross Ulbricht of the former Silk Road. Prosecutors have typically leveled conspiracy charges against the operators of these marketplaces—in Ulbricht’s case, alleging a single drug conspiracy comprising Ulbricht and the thousands of vendors on the Silk Road. This Note argues that the conspiracy to distribute narcotics charge is a poor conceptual fit for the behavior of operators of typical dark net drug marketplaces, and that the federal “crack house” statute provides a better charge. Though charging these operators under the crack house statute would be a novel approach, justice is best served when the crime accurately describes the behavior, as the crack house statute does in proscribing what dark net drug marketplace operators like Ulbricht do
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HPC4Mobilty w/ UCB
The purpose of this project is to examine the energy impact of urban-scale traffic for the Los Angeles Basin by developing and implementing a scalable traffic assignment model. An energy optimization function will be posed and when integrated into the optimization code for travel assignment it can be mathematically proven to converge. The energy optimization function can then be compared to the typical travel time optimization that is traditionally used in traffic assignment models. The analysis will begin with static traffic assignment models with the routing for all origin and destinations computed in parallel on high performance computing facilities. Convergence of the numerical methods rely on the solution of convex programs (or extensions of these). This step will mostly consist of demonstrating the ability to parallelize the Frank Wolfe algorithm on various platforms. This work will contribute to LBNL’s efforts to develop new processes, analytical tools, program designs, and business models to advance the state of the art in next-generation sustainable transportation solutions
The Yarkovsky Drift's Influence on NEAs: Trends and Predictions with NEOWISE Measurements
We used WISE-derived geometric albedos (p_V) and diameters, as well as
geometric albedos and diameters from the literature, to produce more accurate
diurnal Yarkovsky drift predictions for 540 near-Earth asteroids (NEAs) out of
the current sample of \sim 8,800 known objects. As ten of the twelve objects
with the fastest predicted rates have observed arcs of less than a decade, we
list upcoming apparitions of these NEAs to facilitate observations.Comment: Accepted for publication by The Astronomical Journal. 41 pages, 3
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Exploratory wind tunnel tests of a shock-swallowing air data sensor at a Mach number of approximately 1.83
The test probe was designed to measure free-stream Mach number and could be incorporated into a conventional airspeed nose boom installation. Tests were conducted in the Langley 4-by 4-foot supersonic pressure tunnel with an approximate angle of attack test range of -5 deg to 15 deg and an approximate angle of sideslip test range of + or - 4 deg. The probe incorporated a variable exit area which permitted internal flow. The internal flow caused the bow shock to be swallowed. Mach number was determined with a small axially movable internal total pressure tube and a series of fixed internal static pressure orifices. Mach number error was at a minimum when the total pressure tube was close to the probe tip. For four of the five tips tested, the Mach number error derived by averaging two static pressures measured at horizontally opposed positions near the probe entrance were least sensitive to angle of attack changes. The same orifices were also used to derive parameters that gave indications of flow direction
Pressures measured in flight on the aft fuselage and external nozzle of a twin-jet fighter
Fuselage, boundary layer, and nozzle pressures were measured in flight for a twin jet fighter over a Mach number range from 0.60 to 2.00 at test altitudes of 6100, 10,700, and 13,700 meters for angles of attack ranging from 0 deg to 7 deg. Test data were analyzed to find the effects of the propulsion system geometry. The flight variables, and flow interference. The aft fuselage flow field was complex and showed the influence of the vertical tail, nacelle contour, and the wing. Changes in the boattail angle of either engine affected upper fuselage and lower fuselage pressure coefficients upstream of the nozzle. Boundary layer profiles at the forward and aft locations on the upper nacelles were relatively insensitive to Mach number and altitude. Boundary layer thickness decreased at both stations as angle of attack increased above 4 deg. Nozzle pressure coefficient was influenced by the vertical tail, horizontal tail boom, and nozzle interfairing; the last two tended to separate flow over the top of the nozzle from flow over the bottom of the nozzle. The left nozzle axial force coefficient was most affected by Mach number and left nozzle boattail angle. At Mach 0.90, the nozzle axial force coefficient was 0.0013
Michigan Production Costs for Tart Cherries by Production Region
The weighted average cost of producing tart cherries in Michigan on a representative farm in 2009 is 0.04/lb less for mid-sized farms in Northwest Michigan and 0.10/lb in West Central and Southwest Michigan, respectively. --This report was developed through interviews with tart cherry growers and other experts in each of the three main growing regions in 2005 and 2006. Many of the numbers were updated in 2009. --The cost of production calculation is based on estimates of operating costs, harvest costs, and management, interest and tax costs. It also includes an amortized cost of establishing an orchard and employing the land in production (versus some other use). The following tables summarize the cost findings for each of the production regions.Tart cherry, costs, production, Michigan, Agribusiness, Crop Production/Industries, Q100, Q120,
Balancing conservation with national development: a socio-economic case study of the alternatives to the Serengeti Road
Developing countries often have rich natural resources but poor infrastructure to capitalize on them, which leads to significant challenges in terms of balancing poverty alleviation with conservation. The underlying premise in development strategies is to increase the socio-economic welfare of the people while simultaneously ensuring environmental sustainability, however these objectives are often in direct conflict. National progress is dependent on developing infrastructure such as effective transportation networks, however roads can be ecologically catastrophic in terms of disrupting habitat connectivity and facilitating illegal activity. How can national development and conservation be balanced? The proposed Serengeti road epitomizes the conflict between poverty alleviation on one hand, and the conservation of a critical ecosystem on the other. We use the Serengeti as an exemplar case-study in which the relative economic and social benefits of a road can be assessed against the ecological impacts. Specifically, we compare three possible transportation routes and ask which route maximizes the socio-economic returns for the people while minimizing the ecological costs. The findings suggest that one route in particular that circumnavigates the Serengeti links the greatest number of small and medium sized entrepreneurial businesses to the largest labour force in the region. Furthermore, this route connects the most children to schools, provisions the greatest access to hospitals, and opens the most fertile crop and livestock production areas, and does not compromise the ecology and tourism revenue of the Serengeti. This route would improve Tanzania’s food security and self-reliance and would facilitate future infrastructure development which would not be possible if the road were to pass through the Serengeti. This case study provides a compelling example of how a detailed spatial analysis can balance the national objectives of poverty alleviation while maintaining ecological integrity
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