8,107 research outputs found
A luminosity monitor for the A4 parity violation experiment at MAMI
A water Cherenkov luminosity monitor system with associated electronics has
been developed for the A4 parity violation experiment at MAMI. The detector
system measures the luminosity of the hydrogen target hit by the MAMI electron
beam and monitors the stability of the liquid hydrogen target. Both is required
for the precise study of the count rate asymmetries in the scattering of
longitudinally polarized electrons on unpolarized protons. Any helicity
correlated fluctuation of the target density leads to false asymmetries. The
performance of the luminosity monitor, investigated in about 2000 hours with
electron beam, and the results of its application in the A4 experiment are
presented.Comment: 22 pages, 12 figures, submitted to NIM
Investigation of Anaplasma marginale Seroprevalence in a Traditionally Managed Large California Beef Herd.
Recent observations by stakeholders suggested that ecosystem changes may be driving an increased incidence of bovine erythrocytic anaplasmosis, resulting in a reemerging cattle disease in California. The objective of this prospective cohort study was to estimate the incidence of Anaplasma marginale infection using seroconversion in a northern California beef cattle herd. A total of 143 Black Angus cattle (106 prebreeding heifers and 37 cows) were enrolled in the study. Serum samples were collected to determine Anaplasma marginale seroprevalence using a commercially available competitive enzyme-linked immunosorbent assay test kit. Repeat sampling was performed in seronegative animals to determine the incidence density rate from March through September (2013). Seroprevalence of heifers was significantly lower than that of cows at the beginning of the study (P < 0.001) but not at study completion (P = 0.075). Incidence density rate of Anaplasma marginale infection was 8.17 (95% confidence interval: 6.04, 10.81) cases per 1000 cow-days during the study period. Study cattle became Anaplasma marginale seropositive and likely carriers protected from severe clinical disease that might have occurred had they been first infected as mature adults. No evidence was found within this herd to suggest increased risk for clinical bovine erythrocytic anaplasmosis
Whitney coverings and the tent spaces for the Gaussian measure
We introduce a technique for handling Whitney decompositions in Gaussian
harmonic analysis and apply it to the study of Gaussian analogues of the
classical tent spaces of Coifman, Meyer and Stein.Comment: 13 pages, 1 figure. Revised version incorporating referee's comments.
To appear in Arkiv for Matemati
Electrodeposition in capillaries: bottom-up micro- and nanopatterning of functional materials on conductive substrates
A cost-effective and versatile methodology for bottom-up patterned growth of inorganic and metallic materials on the micro- and nanoscale is presented. Pulsed electrodeposition was employed to deposit arbitrary patterns of Ni, ZnO, and FeO(OH) of high quality, with lateral feature sizes down to 200â290 nm. The pattern was defined by an oxygen plasma-treated patterned PDMS mold in conformal contact with a conducting substrate and immersed in an electrolyte solution, so that the solid phases were deposited from the solution in the channels of the patterned mold. It is important that the distance between the entrance of the channels, and the location where deposition is needed, is kept limited. The as-formed patterns were characterized by high resolution scanning electron microscope, energy-dispersive X-ray analysis, atomic force microscopy, and X-ray diffraction
Aksijalni i elektromagnetski nukleonske strukturne funkcije u nefiziÄkom podruÄju
We study the annihilation channel in antiproton-nucleon collisions with production of a single charged or neutral pion and a lepton-antilepton pair. These processes offer a unique possibility to study the nucleon electromagnetic form factors in the unphysical region. The differential cross section in an experimental set-up, where the pion is fully detected, is given with explicit dependence on the relevant nucleon form factors.ProuÄavamo kanal poniĆĄtavanja u sudarima antiprotonânukleon s tvorbom jednog nabijenog ili neutralnog piona i para lepton-antilepton. Ti procesi pruĆŸaju jedinstvenu moguÄnost za prouÄavanje nukleonskih elektromagnetskih strukturnih funkcija u nefiziÄkom podruÄju. Dajemo diferencijalni udarni presjek u mjernoj postavi u kojoj je pion cjelovito detektiran uz izriÄitu ovisnost o dotiÄnim nukleonskim strukturnim funkcijama
Testing axial and electromagnetic nucleon form factors in time-like regions in the processes and , ,
In frame of a phenomenological approach based on Compton-like Feynman
amplitudes, we study the annihilation channel in antiproton nucleon collisions
with production of a single charged or neutral pion and a lepton-antilepton
pair. These reactions allow to access nucleon and axial electromagnetic form
factors in time-like region and offer a unique possibility to study the
kinematical region below two nucleon threshold. The differential cross section
in an experimental set-up where the pion is fully detected is given with
explicit dependence on the relevant nucleon form factors. The possibility to
measure heavy charged pion in the annihilation channel is also discussed.Comment: 23 pages, 9 figure
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