2,653 research outputs found
Experiments in fireless cookery
Citation: Coffman, Edith E. Experiments in fireless cookery. Senior thesis, Kansas State Agricultural College, 1906.Morse Department of Special CollectionsIntroduction: The art of fireless cookery seems to have originated in Germany, where the housewives are noted for their many domestic virtues and especially for the economy of their cooking arrangements. The idea is not new. A fireless stove was exhibited in Paris as early as 1867 under the name of the Norwegian automatic cooker. No notice was taken of it however and the next heard of such an arrangement was from a German housewife who constructed one with a packing of hay for the purpose of keeping food, which had been already cooked, warm for some time. She soon found that the cooking temperature was maintained for several hours and that food which was only partially cooked could be completed in the box. Upon further experimentation it was discovered that for many articles of food from three to five minutes actual boiling on the stove was all that was required as the process would be completed in the box. Other foods, such as cracked wheat, navy beans, and meats require at least one-half hour at the boiling temperature. Many foods are warm enough to serve after ten hours in the box but others require heating through. Some foods, as baked beans, meat and so forth may be partially prepared in the box and then browned in the oven. Of course, the box cannot be used for broiling, frying, baking nor for preparing any food that requires crispness, as the heat necessary to cook the food must be supplied in the food itself or in water surrounding it. Foods cooked in water, as cereals, fruits and vegetables, or those set into a can of water, as custards and brown bread, are most successful in this method of cooking. All that is required in the construction of a fireless stove is a tight box packed well with some non-conducting material
Theoretical study of the design of a catalyst for para to ortho hydrogen conversion
The theory of Petzinger and Scalapino (1973) was thoroughly reviewed, and all of the basic equations for paramagnetic para to ortho hydrogen catalysis re-derived. There are only a few minor phase errors and errors of omission in the description of the theory. Three models (described by Petzinger and Scalapino) for the rate of para to ortho H2 catalysis were worked out, and uniform agreement obtained to within a constant factor of 2 pi. The analytical methods developed in the course of this study were then extended to two new models, which more adequately describe the process of surface catalysis including transfer of hydrogen molecules onto and off of the surface. All five equations for the para to ortho catalytic rate of conversion are described. The two new equations describe the catalytic rate for these models: H2 on the surface is a 2-D gas with lifetime tau; and H2 on the surface is a 2-D liquid undergoing Brownian motion (diffusion) with surface lifetime tau
Ketamine coadministration attenuates morphine tolerance and leads to increased brain concentrations of both drugs in the rat
Background and Purpose The effects of ketamine in attenuating morphine tolerance have been suggested to result from a pharmacodynamic interaction. We studied whether ketamine might increase brain morphine concentrations in acute coadministration, in morphine tolerance and morphine withdrawal. Experimental Approach Morphine minipumps (6mg center dot day(-1)) induced tolerance during 5 days in Sprague-Dawley rats, after which s.c. ketamine (10mg center dot kg(-1)) was administered. Tail flick, hot plate and rotarod tests were used for behavioural testing. Serum levels and whole tissue brain and liver concentrations of morphine, morphine-3-glucuronide, ketamine and norketamine were measured using HPLC-tandem mass spectrometry. Key Results In morphine-naive rats, ketamine caused no antinociception whereas in morphine-tolerant rats there was significant antinociception (57% maximum possible effect in the tail flick test 90min after administration) lasting up to 150min. In the brain of morphine-tolerant ketamine-treated rats, the morphine, ketamine and norketamine concentrations were 2.1-, 1.4- and 3.4-fold, respectively, compared with the rats treated with morphine or ketamine only. In the liver of morphine-tolerant ketamine-treated rats, ketamine concentration was sixfold compared with morphine-naive rats. After a 2 day morphine withdrawal period, smaller but parallel concentration changes were observed. In acute coadministration, ketamine increased the brain morphine concentration by 20%, but no increase in ketamine concentrations or increased antinociception was observed. Conclusions and Implications The ability of ketamine to induce antinociception in rats made tolerant to morphine may also be due to increased brain concentrations of morphine, ketamine and norketamine. The relevance of these findings needs to be assessed in humans.Peer reviewe
Pressurized fluid-submerged, internal, close-range photogrammetry system for laboratory testing
A device for measuring strain and volume of a soil sample including an enclosure adapted to receive a soil sample within another enclosure. A base adapted to hold the sample enclosure. The device also has a plurality of moveable arms located between the enclosures which may be a spaced distance apart and adapted to move around the sample. Cameras as included on the arms
On-line construction of position heaps
We propose a simple linear-time on-line algorithm for constructing a position
heap for a string [Ehrenfeucht et al, 2011]. Our definition of position heap
differs slightly from the one proposed in [Ehrenfeucht et al, 2011] in that it
considers the suffixes ordered from left to right. Our construction is based on
classic suffix pointers and resembles the Ukkonen's algorithm for suffix trees
[Ukkonen, 1995]. Using suffix pointers, the position heap can be extended into
the augmented position heap that allows for a linear-time string matching
algorithm [Ehrenfeucht et al, 2011].Comment: to appear in Journal of Discrete Algorithm
Pressurized fluid-submerged, internal, close-range photogrammetry system for laboratory testing
A device for measuring strain and volume of a soil sample including an enclosure adapted to receive a soil sample within another enclosure. A base adapted to hold the sample enclosure. The device also has a plurality of moveable arms located between the enclosures which may be a spaced distance apart and adapted to move around the sample. Cameras as included on the arms
Unified Solution of the Expected Maximum of a Random Walk and the Discrete Flux to a Spherical Trap
Two random-walk related problems which have been studied independently in the
past, the expected maximum of a random walker in one dimension and the flux to
a spherical trap of particles undergoing discrete jumps in three dimensions,
are shown to be closely related to each other and are studied using a unified
approach as a solution to a Wiener-Hopf problem. For the flux problem, this
work shows that a constant c = 0.29795219 which appeared in the context of the
boundary extrapolation length, and was previously found only numerically, can
be derived explicitly. The same constant enters in higher-order corrections to
the expected-maximum asymptotics. As a byproduct, we also prove a new universal
result in the context of the flux problem which is an analogue of the Sparre
Andersen theorem proved in the context of the random walker's maximum.Comment: Two figs. Accepted for publication, Journal of Statistical Physic
Local symmetry properties of pure 3-qubit states
Entanglement types of pure states of 3 qubits are classified by means of
their stabilisers in the group of local unitary operations. It is shown that
the stabiliser is generically discrete, and that a larger stabiliser indicates
a stationary value for some local invariant. We describe all the exceptional
states with enlarged stabilisers.Comment: 32 pages, 5 encapsulated PostScript files for 3 figures. Published
version, with minor correction
Universal Asymptotic Statistics of Maximal Relative Height in One-dimensional Solid-on-solid Models
We study the probability density function of the maximum relative
height in a wide class of one-dimensional solid-on-solid models of finite
size . For all these lattice models, in the large limit, a central limit
argument shows that, for periodic boundary conditions, takes a
universal scaling form , with the width of the fluctuating interface and the Airy
distribution function. For one instance of these models, corresponding to the
extremely anisotropic Ising model in two dimensions, this result is obtained by
an exact computation using transfer matrix technique, valid for any .
These arguments and exact analytical calculations are supported by numerical
simulations, which show in addition that the subleading scaling function is
also universal, up to a non universal amplitude, and simply given by the
derivative of the Airy distribution function .Comment: 13 pages, 4 figure
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