10,499 research outputs found
Lead-oxygen closed-loop battery system
Calculations show that battery can deliver up to 35 watt-hours per pound, conventional lead-acid batteries deliver 10 to 15 watt-hours per pound. Weight reduction is due to replacement of solid lead-peroxide electrodes with metal current-collector screen, catalyst, and Teflon membrane
The Firms Speak: What the World Business Environment Survey Tells Us about Constraints on Private Sector Development
This chapter summarizes the salient results of the World Business Environment Survey (WBES). It shows that important dimensions of the climate for business operation and investment can be measured, analyzed, and compared across countries, and that governance is key to the business environment and investment climate. The survey findings suggest that key policy, institutional, and governance indicators affect the growth of a firm's sales and investment and the extent to which firms operate in the unofficial economy. Further, the paper provides empirical support for some commonly held notions, while challenging others. It suggests a link between taxation, financing, and corruption on the one hand, and growth and investment on the other, and it highlights the costs to economies where the state is captured by a narrow set of private interests.
Seasonal Variation of Tremetol Concentrations Found in White Snakeroot, Eupatorium rugosum Houtt (Compositae)
White snakeroot is a perennial composite whose foliage is poisonous to livestock. The poison is an unidentified substance contained in a mixture called tremetol. Most cases of poisoning occurred in late summer, and it was presumed livestock were forced to eat the plants because of a dearth of forage. Field observations indicate cattle will voluntarily eat white snakeroot and perhaps the plant varies seasonally in toxicity. Preliminary bioassy using minnows (Notropis spp.) exposed to extracts of plants gathered monthly in 1977 indicated the plants were most toxic in July and August. Tremetol was extracted from plants gathered monthly in 1978. The highest concentrations were from plants gathered in August and September
HESS J1507-622: an unique unidentified source off the Galactic Plane
Galactic very high energy (VHE, > 100 GeV) gamma ray sources in the inner
Galaxy H.E.S.S. survey tend to cluster within 1 degree in latitude around the
Galactic plane. HESS J1507-622 instead is unique, since it is located at
latitude of ~3.5 degrees. HESS J1507-622 is slightly extended over the PSF of
the instrument and hence its Galactic origin is clear. The search for
counterparts in other wavelength regimes (radio, infrared and X-rays) failed to
show any plausible counterparts; and given its position off the Galactic plane
and hence the absorption almost one order of magnitude lower, it is very
surprising to not see any counterparts especially at X-rays wavelengths (by
ROSAT, XMM Newton and Chandra). Its latitude implies that it is either rather
close, within about 1 kpc, or is located well off the Galactic plane. And also
the models reflect the uniqueness of this object: a leptonic PWN scenario would
place this source due to its quite small extension to multi-kpc distance
whereas a hadronic scenario would preferentially locate this object at
distances of < 1 kpc where the density of target material is higher
The form and functions of the avicularia of Bugula (Phylum Ectoprocta)
The most important function of the bird\u27s head avicularium of Bugula simplex and B. stolonifera is that of reducing the tube-building activities of amphipods. These avicularia would probably also be effective in reducing predation by animals of such a size and shape that could be readily seized. That the avicularium is well adapted to such functions is indicated by: 1) the structurally sound design that maximizes the force that can be applied for the least amount of material; 2) the arrangement of the musculature that increases the ability to grasp objects of small diameter; 3) the reaction to mechanical stimuli, namely, nodding and closing the mandible; 4) the placement of avicularia on the colony in positions where they can easily seize crawling organisms. Animals effectively seized by avicularia are those that crawl over the colony and are 0.5 to 4 mm long with either many appendages or wormlike bodies less than 0.05 mm in diameter. Most animals outside this range of size and shape, including most potential predators and larvae of fouling organisms, are inhibited very little by Bugula-type avicularia
Spiders of Dubuque County
A collection of spiders, taken from Dubuque County and neighboring counties in 1961, consisted of representatives of 13 families and 54 species
More than words: Experimental evidence on the negative effects of red tape on quality and procedural justice
More than words: Experimental evidence on the negative effects of red tape on quality and procedural justice
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