12,168 research outputs found
The Spindle-Tuber Disease as a Factor in Seed Potato Production
The lines of experimentation that supplied the data herein reported, stated in very general terms, were as follows: (1) Tuber-line selection studies (2) Relation of environmental conditions to seed-potato production (3) Seed-potato strain trials of certified and uncertified stock (4) Spindle-tuber transmission experiments. Most of these general lines of experimentation will not be completely discussed as a unit in any one part of the bulletin. For the sake of clarity, consecutive thought, and elimination of repetition, data will be selected from any experiment for insertion and discussion under the most logical heading in any part of the bulletin. Unless otherwise stated, all the data presented in this bulletin deal with the Bliss Triumph variety
EC1272 Growing and Storing Progress Potatoes
Extension circular 1272 is about the growing and storing process of potatoes
Equilibrium states and invariant measures for random dynamical systems
Random dynamical systems with countably many maps which admit countable
Markov partitions on complete metric spaces such that the resulting Markov
systems are uniformly continuous and contractive are considered. A
non-degeneracy and a consistency conditions for such systems, which admit some
proper Markov partitions of connected spaces, are introduced, and further
sufficient conditions for them are provided. It is shown that every uniformly
continuous Markov system associated with a continuous random dynamical system
is consistent if it has a dominating Markov chain. A necessary and sufficient
condition for the existence of an invariant Borel probability measure for such
a non-degenerate system with a dominating Markov chain and a finite (16) is
given. The condition is also sufficient if the non-degeneracy is weakened with
the consistency condition. A further sufficient condition for the existence of
an invariant measure for such a consistent system which involves only the
properties of the dominating Markov chain is provided. In particular, it
implies that every such a consistent system with a finite Markov partition and
a finite (16) has an invariant Borel probability measure. A bijective map
between these measures and equilibrium states associated with such a system is
established in the non-degenerate case. Some properties of the map and the
measures are given.Comment: The article is published in DCDS-A, but without the 3rd paragraph on
page 4 (the complete removal of the paragraph became the condition for the
publication in the DCDS-A after the reviewer ran out of the citation
suggestions collected in the paragraph
Imaging ellipsometry of graphene
Imaging ellipsometry studies of graphene on SiO2/Si and crystalline GaAs are
presented. We demonstrate that imaging ellipsometry is a powerful tool to
detect and characterize graphene on any flat substrate. Variable angle
spectroscopic ellipsometry is used to explore the dispersion of the optical
constants of graphene in the visible range with high lateral resolution. In
this way the influence of the substrate on graphene's optical properties can be
investigatedComment: 3 pages, 3 figure
Discovery of a new PG1159 (GW Vir) Pulsator
We report the discovery of pulsations in the spectroscopic PG 1159 type
pre-white dwarf SDSS J075415.12+085232.18. Analysis of the spectrum by Werner,
Rauch and Kepler (2014) indicated Teff=120 000+/-10 000 K, log g=7.0+/-0.3,
mass M=0.52+/-0.02 Msun, C/He=0.33 by number.
We obtained time-series images with the SOAR 4.1 m telescope and 2.1 m Otto
Struve telescope at McDonald Observatory and show the star is also a variable
PG 1159 type star, with dominant period of 525 s.Comment: 5 pages, 3 figure
Exact Energy-Time Uncertainty Relation for Arrival Time by Absorption
We prove an uncertainty relation for energy and arrival time, where the
arrival of a particle at a detector is modeled by an absorbing term added to
the Hamiltonian. In this well-known scheme the probability for the particle's
arrival at the counter is identified with the loss of normalization for an
initial wave packet. Under the sole assumption that the absorbing term vanishes
on the initial wave function, we show that and , where denotes the mean
arrival time, and is the probability for the particle to be eventually
absorbed. Nearly minimal uncertainty can be achieved in a two-level system, and
we propose a trapped ion experiment to realize this situation.Comment: 8 pages, 2 figure
Indomethacin decreases viscosity of gallbladder bile in patients with cholesterol gallstone disease
There is experimental evidence that inhibition of cyclooxygenase with nonsteroidal anti-inflammatory drugs may decrease cholesterol gall-stone formation and mitigate biliary pain in gall-stone patients. The mechanisms by which NSAIDs exert these effect are unclear. In a prospective, controlled clinical trial we examined the effects of oral indomethacin on the composition of human gall-bladder bile. The study included 28 patients with symptomatic cholesterol or mixed gallstones. Of these, 8 were treated with 3 × 25 mg indomethacin daily for 7 days prior to elective cholecystectomy while 20 received no treatment and served as controls. Bile and tissue samples from the gallbladder were obtained during cholecystectomy. Indomethacin tissue levels in the gallbladder mucosa, as assessed by HPLC, were 1.05±0.4 ng/mg wet weight, a concentration known to inhibit effectively cyclooxygenase activity. Nevertheless, no differences between the treated and untreated groups were found in the concentrations of biliary mucus glycoprotein (0.94±0.27 versus 0.93±0.32 mg/ml) or total protein (5.8±0.9 versus 6.4±1.3 mg/ml), cholesterol saturation (1.3±0.2 versus 1.5±0.2), or nucleation time (2.0±3.0 versus 1.5±2.0 days). However, biliary viscosity, measured using a low-shear rotation viscosimeter, was significantly lower in patients receiving indomethacin treatment (2.9±0.6 versus 5.6±1.2 mPa.s; P < 0.02). In conclusion, in man oral indomethacin decreases bile viscosity without alteration of bile lithogenicity or biliary mucus glycoprotein content. Since mucus glycoproteins are major determinants of bile viscosity, an alteration in mucin macromolecular composition may conceivably cause the indomethacin-induced decrease in biliary viscosity and explain the beneficial effects of nonsteroidal anti-inflammatory drugs in gallstone disease
Material modeling in forming simulation of three-dimensional fiber-metal-laminates - A parametric study
Forming of fiber-metal-laminates (FML) into complex geometries is challenging, due to the low fracture toughness of the fibers. Several researchers have addressed this topic in recent years. A new manufacturing process has been introduced in our previous work that successfully combines deep drawing with thermoplastic resin transfer molding (T-RTM) in a single process step. During molding, the fabric is infiltrated with a reactive monomeric matrix, which polymerizes to a thermoplastic after the forming process is completed. In our previous work, a numerical modeling approach was presented for this fully integrated process, investigating a hybrid laminate with 1 mm thick metal sheets of DC04 as top layers and three inner glass fiber layers. Although initial results were promising, there were still some pending issues regarding the modeling of material behavior. The current study aims to address several of these open issues and to provide a general modelling framework for future enhancements. For this purpose, the existing modelling approach is extended and used for parameter analysis. Regarding the influence of different material characteristics on the forming result, shear, bending and compression properties of the fabric are modified systematically. It is shown, that the compression behavior and particularly the tension-compression anisotropy of the fabric is of high importance for modelling the combined forming of fabric and metal. The bending and shear properties of the fabric are negligible small compared to the metal stiffness which dominates the draping process. Finally, it is demonstrated that modelling the fabric layers using continuum shells provides a promising approach for future research, as it enables a suitable way to account for transversal compaction during molding
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