22,107 research outputs found
Implementation of a 2-D 8x8 IDCT on the Reconfigurable Montium Core
This paper describes the mapping of a two-dimensional inverse discrete cosine transform (2-D IDCT) onto a wordlevel reconfigurable Montium Processor. This shows that the IDCT is mapped onto the Montium tile processor (TP) with reasonable effort and presents performance numbers in terms of energy consumption, speed and silicon costs. The Montium results are compared with the IDCT implementation on three other architectures: TI DSP, ASIC and ARM
Comparison of indices for the prediction of nitrogen mineralization after destruction of managed grassland
Intensively managed grasslands are occasionally chemically killed with herbicide and ploughed in order to grow an arable crop. After this management, large N mineralization rates with large losses to the environment are commonly observed. However, it remains to be determined to what extent the chemical killing contribute to increased N mineralization. In this study the potential nitrogen (N) mineralization from grasslands, that were killed with herbicides but otherwise undisturbed, was investigated in a laboratory experiment with undisturbed soil columns. Subsequently we assessed the predictive value of several laboratory indices for N mineralization after chemically killing of the grass. Mineralization rates varied from 0.5 to 3.0 g N m-2 wk-1. The contents of total N, total C, dissolved organic carbon (DOC) and hot-KCl extractable NH4 + were best related to N mineralization rates (R2=50, 48, 38 and 47%, respectively). In combination with information on the N content of the roots and stubble and the age of grassland at destruction, up to 62% of the variation in N mineralization rates could be explained. Although previous studies suggested that dissolved organic nitrogen (DON) is a good indicator for mineralization rates, this was not the case after chemically killing grass in the current study
A Reconfigurable Platform For Cognitive Radio
Today¿s rigid spectrum allocation scheme creates a spectrum scarcity problem for future wireless communications. Measurements show that a wide range of the allocated frequency bands are rarely used. Cognitive radio is a novel approach to improve the spectrum usage, which is able to sense the spectrum and adapt its transmission while coexisting with the licensed spectrum user. A reconfigurable radio platform is required to provide enough adaptivity for cognitive radio. In this paper, we propose a cognitive radio system architecture and discuss its possible implementation on a heterogeneous reconfigurable radio platform
Sexual hormones in Achyla. V. Properties of hormone A of Achyla bisexualis
1. The hormonal coordinating mechanism of the sexual process in Achlya is briefly reviewed.
2. A technique is described for culturing the female plant of Achlya bisexualis in sufficient quantity to furnish material for the chemical study of hormone A.
3. A modification of the biological assay for hormone A is described.
4. Many of the properties of hormone A have been determined: (a) solubilities in common organic solvents, (b) adsorption, (c) stability, (d) inactivation, and (e) reactions with certain reagents.
5. A procedure is described whereby enormous enrichment of the active principle has been achieved
W-Particle Distribution in ElectroWeak Tachyonic Pre-Heating
Results are presented of a numerical study of the distribution of W-bosons
generated in a tachyonic electroweak pre-heating transitionComment: Contribution to Strong and ElectroWeak Matter 2002, 5 page
Simulations of Cold Electroweak Baryogenesis: Finite time quenches
The electroweak symmetry breaking transition may supply the appropriate
out-of-equilibrium conditions for baryogenesis if it is triggered sufficiently
fast. This can happen at the end of low-scale inflation, prompting baryogenesis
to occur during tachyonic preheating of the Universe, when the potential energy
of the inflaton is transfered into Standard Model particles. With the proper
amount of CP-violation present, the observed baryon number asymmetry can be
reproduced. Within this framework of Cold Electroweak Baryogenesis, we study
the dependence of the generated baryon asymmetry on the speed of the quenching
transition. We find that there is a separation between ``fast'' and ``slow''
quenches, which can be used to put bounds on the allowed Higgs-inflaton
coupling. We also clarify the strong Higgs mass dependence of the asymmetry
reported in a companion paper (hep-ph/0604263).Comment: 18 pages, 20 figure
A new method for the separation of androgens from estrogens and for the partition of estriol from the estrone-estradiol fraction: with special reference to the identification and quantitative microdetermination of estrogens by ultraviolet absorption spectrophotometry
It is recognized generally that a qualitative and quantitative knowledge of the excretion pattern of the urinary estrogens is one index to an understanding of the functional activity of the ovary and adrenal cortex. Obviously, such determinations may be useful also in evaluating the normal and abnormal functions of other physiologically related endocrine glands as well as of organs like the liver and kidneys. The clinical applications of these data are self-evident.
Various attempts have been made to circumvent the notoriously inaccurate values which have been obtained for the urinary estrogens by a variety of bioassay methods and calorimetric techniques (1, 2). The acknowledged shortcomings of these methods have led us to investigate the application of ultraviolet absorption spectrophotometry to the quantitative determination of the urinary estrogens in an attempt to develop an objective physical method for their accurate determination. It is known that the infra-red portion of the spectrum yields more differentially characteristic curves, but those of the ultraviolet range are more readily obtainable, and consequently better adapted to clinical use.
This communication is concerned with studies of the following aspects of the problem: (1) spectrophotometric identification and quantitative micro determination of crystalline estrogens; (2) detection by spectrophotometric assay of gross errors in current methods for extraction and partition of estrogens; (3) studies on the ultraviolet absorption of substances comprising the background material; (4) separation of the phenolic estrogens from the so called neutral steroid fraction; (5) separation of urinary estrogens from other urinary phenolic substances by steam distillation; (6) micro-Girard separation of estrone from estradiol; (7) an essentially new method for the extraction and partition of crystalline estrone, estradiol, and estriol, and their quantitative assay by ultraviolet spectrophotometry
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Prototyping Large-Sized Objects Using Freeform Thick Layers of Plastic Foam
Current Rapid Prototyping systems are primarily aimed at small-sized objects containing many
shape details. In this paper a Rapid Prototyping technology is presented that is aimed at largesized objects having a complex, freeform outer shape. This new technology builds the model out
ofthick layers, each having freeform outside faces. The paper will present: an overview of current
methods to produce large prototypes, the basics of the new method, the technology used to
produce the layers, the toolpath planning and finally the overall system design.Mechanical Engineerin
Topical Results on Lattice Chiral Fermions in the CFA
We report new results on the lattice regularization of the chiral Schwinger
model and the chiral U(1) model in four dimensions in the CFA.Comment: LATTICE98(chiral
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