Spread in flat rolling

A velocity field was derived for a flat workpiece undergoing plastic deformation between cylindrical rolls in a rolling mill. Using the velocity field, an expression was written for the total power input required for the rolling process in terms of the process parameters: roll diameter, thickness reduction, workpiece geometry, surface friction, and spread. The Upper Bound Theorem was applied to the power expression to establish an upper limit on it. This limit was minimized with respect to spread to determine the value of spread requiring the least amount of input power

A Study of the Effects of Atmospheric Phenomena on Mars Science Laboratory Entry Performance

At Earth during entry the shuttle has experienced what has come to be known as potholes in the sky or regions of the atmosphere where the density changes suddenly. Because of the small data set of atmospheric information where the Mars Science Laboratory (MSL) parachute deploys, the purpose of this study is to examine the effect similar atmospheric pothole characteristics, should they exist at Mars, would have on MSL entry performance. The study considers the sensitivity of entry design metrics, including altitude and range error at parachute deploy and propellant use, to pothole like density and wind phenomena

Asymptotic Parachute Performance Sensitivity

In 2010, the Mars Science Laboratory mission will pioneer the next generation of robotic Entry, Descent, and Landing systems by delivering the largest and most capable rover to date to the surface of Mars. In addition to landing more mass than any other mission to Mars, Mars Science Laboratory will also provide scientists with unprecedented access to regions of Mars that have been previously unreachable. By providing an Entry, Descent, and Landing system capable of landing at altitudes as high as 2 km above the reference gravitational equipotential surface, or areoid, as defined by the Mars Orbiting Laser Altimeter program, Mars Science Laboratory will demonstrate sufficient performance to land on 83% of the planet s surface. By contrast, the highest altitude landing to date on Mars has been the Mars Exploration Rover at 1.3 km below the areoid. The coupling of this improved altitude performance with latitude limits as large as 60 degrees off of the equator and a precise delivery to within 10 km of a surface target, will allow the science community to select the Mars Science Laboratory landing site from thousands of scientifically interesting possibilities. In meeting these requirements, Mars Science Laboratory is extending the limits of the Entry, Descent, and Landing technologies qualified by the Mars Viking, Mars Pathfinder, and Mars Exploration Rover missions. Specifically, the drag deceleration provided by a Viking-heritage 16.15 m supersonic Disk-Gap-Band parachute in the thin atmosphere of Mars is insufficient, at the altitudes and ballistic coefficients under consideration by the Mars Science Laboratory project, to maintain necessary altitude performance and timeline margin. This paper defines and discusses the asymptotic parachute performance observed in Monte Carlo simulation and performance analysis and its effect on the Mars Science Laboratory Entry, Descent, and Landing architecture

Boom for a load handling machine

A boom for a load handling machine, the boom has a mounting by which the boom is mounted on a body of the machine, and at least first and second telescoped sections. In use, the boom carries a load handling implement at or towards its outermost end. The first boom section is telescoped within the second section and is extendible and retractable relative to the second boom section by an actuator. At least the first boom section includes walls made at least predominantly of a composite material. A bearing member is located where adjacent walls meet to extend along a substantial length of the first boom section to provide bearing surfaces during sliding of the first boom section relative to the second boom section. Bearings also may be provided on the interior of the second boom section to further protect the first boom section

Boom for a load handling machine

A boom (12) for a load handling machine (10), the boom (12) has a mounting (20) by which the boom (12) is mounted on a body (11) of the machine (10), and first and second telescoped sections (24), the boom (12) carrying in use, at or towards its outermost end, a load handling implement (27), the second boom (24) section being telescoped within the first section and being extendible and retractable relative to the first boom sections (22) by actuating means, characterised in that at least one of the boom sections (22, 25) includes a plurality of walls (25a, 25b, 25c, 25d) each being a web made at least predominantly of a composite material, and where adjacent walls meet there being bearing members (30/35; 30a) which extend along a substantial length of the boom section (22, 25) to provide bearing surfaces (31) during sliding of the second boom section (25) relative to the first boom section (22)

Pan American Climate Study (PACS) mooring deployment cruise report : R/V Roger Revelle cruise number Genesis 4, 9 April-5 May 1997

Three surface moorings were deployed in the eastern equatorial Pacifc from the R/V Roger Revelle as part of the Pan American Climate Study (PACS). PACS is a NOAA-funded study with the goal of investigating links between sea surface temperature varabilty in the tropical oceans near the Americas and climate over the American continents. The three moorings were deployed near 125°W, spanning the strong meridional sea surface temperature gradient associated with the cold tongue south of the equator and the warmer ocean north of the equator, near the northernmost, summer location of the Intertropical Convergence Zone. The mooring deployment was done to improve understading of the air-sea fluxes and of the processes that control the evolution of the sea surface temperature field in the region. Two surface moorings of the Upper Ocean Processes Group at the Woods Hole Oceanographic Institution (WHOI) were deployed-one at 3°S, 125°W and the other at lO°N, 125°W. One mooring from the Ocean Circulation Group (R. Weisberg) at the University of South Florida (USP) was deployed on the equator at 128°W. The buoys of the two WHOI moorings were each equipped with meteorological instrmentation, including a Vector Averaging Wind Recorder, and an Improved Meteorological (IMET) system. The WHOI moorings also carried Vector Measurng Current Meters, single-point temperature recorders, and conductivity and temperature recorders located in the upper 200 meters of the mooring line. In addition to the instrumentation noted above, a variety of other instruments, including an acoustic current meter, acoustic doppler current meters, bio-optical instrument packages and an acoustic rain gauge, were deployed during the PACS field program. The USF mooring had an IMET system on the surface buoy and for oceanographic instrumentation, two RD Instruments acoustic doppler current profilers, single-point temperature recorders, and conductivity and temperature recorders. Conductivity-temperature-depth (CTD) profiles were made at each mooring site and during the transit between mooring locations. This report describes, in a general manner, the work that took place durig the Genesis 4 cruise aboard the R/V Roger Revelle. The three surface moorings deployed during this cruise will be recovered and re-deployed after approximately nine months, with a final recovery planned for 17 months after the first setting. Details of the mooring designs and preliminary data from the CT profies are included.Funding was provided by the National Oceanic and Atmospheric Administration under Contract No. NA66GP0130

Parachute Models Used in the Mars Science Laboratory Entry, Descent, and Landing Simulation

An end-to-end simulation of the Mars Science Laboratory (MSL) entry, descent, and landing (EDL) sequence was created at the NASA Langley Research Center using the Program to Optimize Simulated Trajectories II (POST2). This simulation is capable of providing numerous MSL system and flight software responses, including Monte Carlo-derived statistics of these responses. The MSL POST2 simulation includes models of EDL system elements, including those related to the parachute system. Among these there are models for the parachute geometry, mass properties, deployment, inflation, opening force, area oscillations, aerodynamic coefficients, apparent mass, interaction with the main landing engines, and off-loading. These models were kept as simple as possible, considering the overall objectives of the simulation. The main purpose of this paper is to describe these parachute system models to the extent necessary to understand how they work and some of their limitations. A list of lessons learned during the development of the models and simulation is provided. Future improvements to the parachute system models are proposed

Atomic Resonance and Scattering

Contains reports on nine research projects.U.S. Energy Research and Development Administration (Contract EG-77-S-02-4370)U. S. Air Force - Office of Scientific Research (Contract F44620-72-C-0057)Joint Services Electronics Program (Contract DAAB07-76-C-1400)National Science Foundation (Grant PHY75-15421-AO1)National Science Foundation (Grant PHY77-09155)National Science Foundation (Grant CHE76-81750)U. S. Air Force - Office of Scientific Research (Grant AFOSR-76-2972A

Regioselective synthesis of plant (iso)flavone glycosides in Escherichia coli

The flavonoids genistein, biochanin A, luteolin, quercetin, and kaempferol are plant natural products with potentially useful pharmacological and nutraceutical activities. These natural products usually exist in plants as glycosides, and their glycosylation has a remarkable influence on their pharmacokinetic properties. The glycosyltransferases UGT71G1 and UGT73C8 from Medicago truncatula are excellent reagents for the regioselective glycosylation of (iso)flavonoids in Escherichia coli grown in Terrific broth. Ten to 20 mg/L of either genistein or biochanin A 7-O-glucoside was produced after feeding genistein or biochanin A to E. coli expressing UGT71G1, and similar levels of luteolin 4’-O- and 7-O-glucosides were produced after feeding luteolin to cultures expressing UGT73C8. For the production of kaempferol 3-O-glucoside or quercetin 3-O-glucoside, the Phe148Val or Tyr202Ala mutants of UGT71G1 were employed. Ten to 16 mg/L of either kaempferol 3-O- or quercetin 3-O-glucosides were produced on feeding kaempferol or quercetin to E. coli expressing these enzymes. More than 90% of the glucoside products were released to the medium, facilitating their isolation

Epigenetic and Genetic Factors Predict Women's Salivary Cortisol following a Threat to the Social Self

10.1371/journal.pone.0048597PLoS ONE711