352 research outputs found
Finitely generated ideal languages and synchronizing automata
We study representations of ideal languages by means of strongly connected
synchronizing automata. For every finitely generated ideal language L we
construct such an automaton with at most 2^n states, where n is the maximal
length of words in L. Our constructions are based on the De Bruijn graph.Comment: Submitted to WORDS 201
Sequential injection titration of chloride in milk with potentiometric detection
In this work, a sequential injection system for the pseudo-titration of chloride in milk is described. Milk was directly aspirated
into the system and sandwiched between two silver nitrate plugs (titrant). The aspirated zones were then propelled to the detector
(Ag2S/Ag tubular electrode), where the depletion in the titrant silver concentration (due to the formation of a AgCl precipitate) was
monitored. The results obtained by the developed sequential injection titration method were not statistically different from those
provided by the potentiometric reference procedure with relative standard deviations better than 3.4%. The sampling rates achieved
were 17 samples per hour.info:eu-repo/semantics/acceptedVersio
Determination of nitrate and nitrite in dairy samples by sequential injection using an in-line cadmium-reducing column
A sequential injection analysis (SIA) system for the spectrophotometric determination of nitrate in dairy samples was developed. A test
portion was aspirated into a carrier solution containing ethylendiaminetetracetic acid (EDTA) and ammonium buffer, which flowed into
a copperized cadmium reduction column installed in-line for the determination of the nitrate plus nitrite contents of samples. For the
nitrite determination, another test portion of sample was aspirated and directly sent to the detector without reduction. Nitrate content
was calculated from the difference between nitrate plus nitrite (expressed as nitrite) and nitrite content. The spectrophotometric
determination is based on the Griess reaction. The proposed method was used to test several dairy samples (ultrapasteurized milk with
1.7% milk fat, whey, raw bovine milk and several cheese varieties). Results were statistically in good agreement with those provided by
the reference procedure, with a detection limit of 0.15 mgL 1. A sampling rate of 21 determinations per hour can be achieved with this
procedure
Ramond-Ramond Fields, Fractional Branes and Orbifold Differential K-Theory
We study D-branes and Ramond-Ramond fields on global orbifolds of Type II
string theory with vanishing H-flux using methods of equivariant K-theory and
K-homology. We illustrate how Bredon equivariant cohomology naturally realizes
stringy orbifold cohomology. We emphasize its role as the correct cohomological
tool which captures known features of the low-energy effective field theory,
and which provides new consistency conditions for fractional D-branes and
Ramond-Ramond fields on orbifolds. We use an equivariant Chern character from
equivariant K-theory to Bredon cohomology to define new Ramond-Ramond couplings
of D-branes which generalize previous examples. We propose a definition for
groups of differential characters associated to equivariant K-theory. We derive
a Dirac quantization rule for Ramond-Ramond fluxes, and study flat
Ramond-Ramond potentials on orbifolds.Comment: 46 pages; v2: typos correcte
Preliminary Results on Light Conditions Manipulation in Octopus vulgaris (Cuvier, 1797) Paralarval Rearing
High paralarvae mortality is a major bottleneck currently hindering the control over the lifecycle of common octopus (Octopus vulgaris Cuvier, 1797). It is believed that this problem might be related to either zoo-technical and/or nutritional aspects. The present paper is focused on the study of different zoo-technical aspects related to light conditions on the rearing of paralarvae, including the effects of polarization in prey ingestion, the use of a blue filter to simulate natural conditions, and the use of focused light to avoid reflections of the rearing tank’s walls. In the first experiment, O. vulgaris paralarvae ingestion of Artemia sp. and copepods (Tisbe sp.) was assessed under either normal or polarized light. In the second experiment, the effect of a blue filter with natural light or focused artificial light on growth and mortality was assessed over 15 days of rearing. Ingestion rate was not influenced by light polarization. Nonetheless, a significantly higher ingestion of Artemia sp. with respect to copepods was observed. The blue filter promoted the use of natural light conditions in Octopus paralarval culture, while focused light reduced the collision of the paralarvae against the walls. However, no significant differences were found in paralarval growth nor survivalEn prens
Branching Fractions for D0 -> K+K- and D0 -> pi+pi-, and a Search for CP Violation in D0 Decays
Using the large hadroproduced charm sample collected in experiment E791 at
Fermilab, we have measured ratios of branching fractions for the two-body
singly-Cabibbo-suppressed charged decays of the D0:
(D0 -> KK)/(D0 -> Kpi) = 0.109 +- 0.003 +- 0.003,
(D0 -> pipi)/(D0 -> Kpi) = 0.040 +- 0.002 +- 0.003, and
(D0 -> KK)/(D0 -> pipi) = 2.75 +- 0.15 +- 0.16. We have looked for
differences in the decay rates of D0 and D0bar to the CP eigenstates K+K- and
pi+pi-, and have measured the CP asymmetry parameters
A_CP(K+K-) = -0.010 +- 0.049 +- 0.012 and
A_CP(pi+pi-) = -0.049 +- 0.078 +- 0.030, both consistent with zero.Comment: 10 Postscript pages, including 2 figures. Submitted to Phys. Lett.
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