18,951 research outputs found
Shock-operated valve would automatically protect fluid systems
Glandless valve shuts down high-pressure fluid systems when severe shock from an explosion or earthquake occurs. The valve uses a pendulum to support the valve closure plug in the open position. When jarred, the valve body is moved relative to the pendulum and the plug support is displaced, allowing the plug to seat and be held by spring pressure
Oral Health Advice for People With Serious Mental Illness
People with serious mental illness experience an erosion of functioning in day-to-day life over a protracted period of time. There is also evidence to suggest that people with serious mental illness have a greater risk of experiencing oral disease and have greater oral treatment needs than the general population. However, oral health has never been seen as a priority in people suffering with serious mental illness
Temporal frequency of radio emissions for the April 25, 1984 flare
The National Geophysical Data Center archives data of the solar-terrestrial environment. The USAF Radio Solar Telescope Network (RSTN) data allow performance of time series analysis to determine temporal oscillations as low as three seconds. The X13/3B flare which erupted in region 4474 (S12E43) on the 24 to 25 of April 1984, was selected. The soft X-rays, 1 to 8 A, remained above X-levels for 50 minutes and the radio emissions measured at Learmonth Solar Observatory reached a maximum of 3.15 x 10 to the 5th power SFUs at 410 MHz at 0000UT. A power spectral analysis of the fixed frequency RSTN data from Learmonth shows possible quasi-periodic fluctuations in the range two to ten seconds. Repetition rates or quasi-periodicities, in the case of the power spectral analysis, generally showed the same trends as the average solar radio flux at 245 and 8800 MHz. The quasi-periodicities at 1415 MHz showed no such trends
Fourier, Gauss, Fraunhofer, Porod and the Shape from Moments Problem
We show how the Fourier transform of a shape in any number of dimensions can
be simplified using Gauss's law and evaluated explicitly for polygons in two
dimensions, polyhedra three dimensions, etc. We also show how this combination
of Fourier and Gauss can be related to numerous classical problems in physics
and mathematics. Examples include Fraunhofer diffraction patterns, Porods law,
Hopfs Umlaufsatz, the isoperimetric inequality and Didos problem. We also use
this approach to provide an alternative derivation of Davis's extension of the
Motzkin-Schoenberg formula to polygons in the complex plane.Comment: 21 pages, no figure
PMI: A Delta Psi(m) Independent Pharmacological Regulator of Mitophagy
Mitophagy is central to mitochondrial and cellular homeostasis and operates via the PINK1/Parkin pathway targeting mitochondria devoid of membrane potential (ΔΨm) to autophagosomes. Although mitophagy is recognized as a fundamental cellular process, selective pharmacologic modulators of mitophagy are almost nonexistent. We developed a compound that increases the expression and signaling of the autophagic adaptor molecule P62/SQSTM1 and forces mitochondria into autophagy. The compound, P62-mediated mitophagy inducer (PMI), activates mitophagy without recruiting Parkin or collapsing ΔΨm and retains activity in cells devoid of a fully functional PINK1/Parkin pathway. PMI drives mitochondria to a process of quality control without compromising the bio-energetic competence of the whole network while exposing just those organelles to be recycled. Thus, PMI circumvents the toxicity and some of the nonspecific effects associated with the abrupt dissipation of ΔΨm by ionophores routinely used to induce mitophagy and represents a prototype pharmacological tool to investigate the molecular mechanisms of mitophagy
Curling Burley Tobacco from an Automated Harvesting System
If burley tobacco can be successfully cured at high density under waterproof covers in the field, a producer can expand production without the necessity of building new curing barns and can thereby more easily justify investment in the automated burley tobacco harvesting system (Wells et al., 1990a, b). Curing under waterproof covers in the field and curing on frames in the barn were evaluated over three curing seasons using two varieties (KY 14 and TN 86), two plant densities (32 and 43 plants/m2, 3 and 4 plants/ft2), position of tobacco on the frame (four levels ranging from edge to center) and stalk position (bottom, middle and top). Conventionally cured tobacco was used as the standard of comparison and grade index was used as the assessment of quality.
Averaged over a three-year period, burley tobacco cured in the field over sod and under waterproof covers and conventionally cured tobacco were of equal quality (56.0 and 55.8 grade index, respectively) and were both superior to tobacco cured on frames in the barn (52.0). During the dry curing season, burley tobacco cured under the covers had a higher grade index (54.9) than that cured conventionally (43.5) or on frames in the barn (43.7) but during the moderately wet and wet curing seasons, conventionally cured burley tobacco had a higher grade index (62.3 and 61.5, respectively) than that cured under covers (58.9 and 54.2, respectively) or on frame in the barn (59.0 and 53.4, respectively). During the wet curing season, leaf tips near the sod in the field and near the concrete in the barn cured dark red resulting in a lowered grade index. Burley tobacco from the automated harvesting system is better cured outside under waterproof covers than cured in a barn
Elliptical Combing Motion for Harvesting Bell Peppers
A new concept for mechanically harvesting bell peppers, intended specifically for multiple-pass harvesting, utilized spaced horizontal fingers combing vertically upward through plant foliage in an elliptical path alternating from both sides of the row. An apparatus based on this concept was designed and built, and harvest tests were conducted to determine the effect of two main machine operating parameters, vertical picking speed and disk angle. Harvesting performance was evaluated in terms of harvest efficiency, fruit damage, and plant damage as it related to multiple-pass harvesting. Fruit removal, both harvestable size and immature, increased significantly as vertical picking speed increased. Branch breakage also tended to increase as vertical picking speed increased, partially accounting for the increased fruit removal. Fruit damage increased significantly as the disk angle increased. Overall, the average harvest efficiency for the tests was 81% and the average fruit damage was 5.9%
Traction Characteristics of Prepared Traffic Lanes
Traction characteristics of lugged and smooth tires were compared on prepared traffic lanes and on conventional seedbed conditions. Results indicated that elevated traffic lanes offer important traction advantages over seedbeds in wet soil conditions. In dry soil conditions, traction on elevated traffic lanes was sometimes less than on the seedbed conditions. A timeliness advantage in mobility for the elevated traffic lanes was found to be up to 2 days in extremely wet conditions. A non-elevated traffic lane showed no traction advantage in wet conditions
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