13,582 research outputs found
Intellectual Property, Antitrust and Strategic Behavior
Economic growth depends in large part on technological change. Laws governing intellectual property rights protect inventors from competition in order to create incentives for them to innovate. Antitrust laws constrain how a monopolist can act in order to maintain its monopoly in an attempt to foster competition. There is a fundamental tension between these two different types of laws. Attempts to adapt static antitrust analysis to a setting of dynamic R&D competition through the use of 'innovation markets' are likely to lead to error. Applying standard antitrust doctrines such as tying and exclusivity to R&D settings is likely to be complicated. Only detailed study of the industry of concern has the possibility of uncovering reliable relationships between innovation and industry behavior. One important form of competition, especially in certain network industries, is between open and closed systems. We have presented an example to illustrate how there is a tendency for systems to close even though an open system is socially more desirable. Rather than trying to use the antitrust laws to attack the maintenance of closed systems, an alternative approach would be to use intellectual property laws and regulations to promote open systems and the standard setting organizations that they require. Recognition that optimal policy toward R&D requires coordination between the antitrust and intellectual property laws is needed.
Serrated trailing edges for improving lift and drag characteristics of lifting surfaces
An improvement in the lift and drag characteristics of a lifting surface is achieved by attaching a serrated panel to the trailing edge of the lifting surface. The serrations may have a saw-tooth configuration, with a 60 degree included angle between adjacent serrations. The serrations may vary in shape and size over the span-wise length of the lifting surface, and may be positioned at fixed or adjustable deflections relative to the chord of the lifting surface
Dual-purpose self-deliverable lunar surface PV electrical power system
A safe haven and work supported PV power systems on the lunar surface will likely be required by NASA in support of the manned outpost scheduled for the post-2000 lunar/Mars exploration and colonization initiative. Initial system modeling and computer analysis shows that the concept is workable and contains no major high risk technology issues which cannot be resolved in the circa 2000 to 2025 timeframe. A specific selection of the best suited type of electric thruster has not been done; the initial modeling was done using an ion thruster, but Rocketdyne must also evaluate arc and resisto-jets before a final design can be formulated. As a general observation, it appears that such a system can deliver itself to the Moon using many system elements that must be transported as dead payload mass in more conventional delivery modes. It further appears that a larger power system providing a much higher safe haven power level is feasible if this delivery system is implemented, perhaps even sufficient to permit resource prospecting and/or lab experimentation. The concept permits growth and can be expanded to include cargo transport such as habitat and working modules. In short, the combined payload could be manned soon after landing and checkout. NASA has expended substantial resources in the development of electric propulsion concepts and hardware that can be applied to a lunar transport system such as described herein. In short, the paper may represent a viable mission on which previous investments play an invaluable role. A more comprehensive technical paper which embodies second generation analysis and system size will be prepared for near-term presentation
Putting zoo animal cancer into perspective
As part of a comparative research agenda that promises insights that help extend the human lifespan and combat cancer, cancer prevalence in zoo animals has received recent attention. Here, we want to draw attention to a principle of cancer research that was introduced into the zoo world as early on as 1933, but that seems to have gone somewhat forgotten: Cancer is mainly a disease of old age, and therefore studies aiming at identifying taxa that are particularly susceptible or resistant to cancer must control for whether the respective zoo populations are âold.â In a comparative context, âold ageâ cannot be measured in absolute terms (e.g., years), but only in relation to a species' maximum lifespan: Species that achieve, across zoos, a higher mean lifespan as a percent of their maximum lifespan are âolder.â When applying this metric to former as well as more recently published data on cancer prevalence, it appears that those species that become relatively old in zoosâin particular, the carnivoresâhave a relatively high cancer prevalence. Any improvement in animal husbandryâwhich reduces premature deathsâshould, by default, lead to more cancer. Cancer in zoo animals, like any other oldâage condition, might therefore be embraced as a proxy for good husbandry. Rather than following a sensationalist approach that dramatizes disease and death per se, zoos should be clear about what their husbandry goals are, what relative longevities they want to achieve for which species, and what oldâage diseases they should therefore expect: in the end, one has to die of something
A CD-ROM Based Agricultural Information Retrieval System
An information retrieval system for agricultural extension was developed using CD-ROM technology as the primary medium for information delivery. Object-oriented database techniques were used to organize the information. Conventional retrieval techniques including hypertext, fulltext searching, and relational databases, and decision support programs such as expert systems were integrated into a complete package for accessing information stored on the CDROM. A multimedia user interface was developed to provide a variety of capabilities including computer graphics and high-resolution digitized images. Information for the disk was gathered and entered using extension publications which were tagged using an SGML-based document markup language. The fully operational CD-ROM system has been implemented in all 67 county extension offices in Flori
Growth rate of YBCO single grains containing Y-2411(M)
Y-Ba-Cu-O (YBCO) single grains have the potential to generate large trapped magnetic fields for a variety of engineering applications, and research on the processing and properties of this material has attracted world-wide interest. In particular, the introduction of flux pinning centres to the large grain microstructure to improve its current density, Jc, and hence trapped field, has been investigated extensively over the past decade. Y 2Ba4CuMOx [Y-2411(M)], where M = Nb, Ta, Mo, W, Ru, Zr, Bi and Ag, has been reported to form particularly effective flux pinning centres in YBCO due primarily to its ability to exist as nano-size inclusions in the superconducting phase matrix. However, the addition of the Y-2411(M) phase to the precursor composition complicates the melt-processing of single grains. We report an investigation of the growth rate of single YBCO grains containing Y-2411(Bi) phase inclusions and Y2O3. The superconducting properties of these large single grains have been measured specifically to investigate the effect of Y2O3 on broadening the growth window of these materials
A Search for Young Stars in the S0 Galaxies of a Super-Group at z=0.37
We analyze Galaxy Evolution Explorer UV data for a system of four gravitationally bound groups at z = 0.37, SG1120, which is destined to merge into a Coma-mass cluster by z = 0, to study how galaxy properties may change during cluster assembly. Of the 38 visually classified S0 galaxies, with masses ranging from log (M *)[M â] â 10-11, we detect only one in the near-UV (NUV) channel, a strongly star-forming S0 that is the brightest UV source with a measured redshift placing it in SG1120. Stacking the undetected S0 galaxies (which generally lie on or near the optical red sequence of SG1120) still results in no NUV/far-UV (FUV) detection (\u3c2Ï). Using our limit in the NUV band, we conclude that for a rapidly truncating star formation rate, star formation ceased at least ~0.1-0.7 Gyr ago, depending on the strength of the starburst prior to truncation. With an exponentially declining star formation history over a range of timescales, we rule out recent star formation over a wide range of ages. We conclude that if S0 formation involves significant star formation, it occurred well before the groups were in this current pre-assembly phase. As such, it seems that S0 formation is even more likely to be predominantly occurring outside of the cluster environment
A small sealed Ta crucible for thermal analysis of volatile metallic samples
Differential thermal analysis on metallic alloys containing volatile elements
can be highly problematic. Here we show how measurements can be performed in
commercial, small-sample, equipment without modification. This is achieved by
using a sealed Ta crucible, easily fabricated from Ta tubing and sealed in a
standard arc furnace. The crucible performance is demonstrated by measurements
on a mixture of Mg and MgB, after heating up to 1470. We
also show data, measured on an alloy with composition GdMg, that
clearly shows both the liquidus and a peritectic, and is consistent with
published phase diagram data
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