2,165 research outputs found
An open reply to "What is going on at the Library of Congress?" by Thomas Mann
This is an open response to a report by Thomas Mann at the Library of Congress concerning changes in cataloging. The author contends that, although the current changes at the Library of Congress are suspect, changes are imminent and experienced catalogers must offer positive suggestions for change, otherwise they will be ignored by management
Non-oscillation probes of neutrino masses
The absolute scale of neutrino masses is very important for understanding the
evolution and the structure formation of the universe as well as for nuclear
and particle physics beyond the present Standard Model. Complementary to
deducing statements on the neutrino mass from cosmological observations two
different methods to determine the neutrino mass scale in the laboratory are
pursued: the search for neutrinoless double beta decay and the direct neutrino
mass search. For both methods currently experiments with a sensitivity of order
100 meV are being set up or commissioned.Comment: 13 pages, 5 figures Proceedings of the 11th International Workshop on
Neutrino Factories, Superbeams and Beta Beams NUFACT09, editor: Dan Kaplan,
AI
Beta decay in external field and neutrino mass
The results of the investigation of electromagnetic field effects on the
process of beta decay are used for analyzing experimental data on direct
neutrino mass search.Comment: 7 pages, 7 figures, late
Limit on sterile neutrino contribution from the Mainz Neutrino Mass Experiment
The recent analysis of the normalization of reactor antineutrino data, the
calibration data of solar neutrino experiments using gallium targets, and the
results from the neutrino oscillation experiment MiniBooNE suggest the
existence of a fourth light neutrino mass state with a mass of O(eV), which
contributes to the electron neutrino with a sizable mixing angle. Since we know
from measurements of the width of the Z0 resonance that there are only three
active neutrinos, a fourth neutrino should be sterile (i.e., interact only via
gravity). The corresponding fourth neutrino mass state should be visible as an
additional kink in beta-decay spectra. In this work the phase II data of the
Mainz Neutrino Mass Experiment have been analyzed searching for a possible
contribution of a fourth light neutrino mass state. No signature of such a
fourth mass state has been found and limits on the mass and the mixing of this
fourth mass states are derived
Wastewater treatment using tidal flow wetlands
Over the last century wastewater treatment has evolved immensely. This development is divided into two different ways of wastewater treatment. There are highly engineered wastewater treatment systems, which can achieve high treatment standards on a small area. And on the other hand there are natural treatment systems, such as constructed wetlands (CWs) that need large areas to achieve suitable treatment. Besides the difference of land area required by each of those systems they largely differ in the energy they require to perform such wastewater treatment.
This study investigates a new type of wastewater treatment system, the Tidal Flow Wetland (TFW). This system is part of a new generation of engineered treatment wetlands that aim to close the gap between highly engineered smaller systems and large CWs that treat wastewater naturally.
This study provides a comparison of different wastewater treatment options that are in direct competition to TFWs. It determines advantages and disadvantages of various systems for different situations. Furthermore a hypothetical wastewater situation for a small residential development has been developed to be able to compare a TFW and a conventional CW.
Overall the TFW achieved the same treatment standard to the hybrid conventional CW on less than a quarter of the area, while keeping energy consumption minimal. The results of the comparison also confirm the outstanding total nitrogen (TN) removal capability. While the TFW could achieve TN removal on only 24 m2, the hybrid system required more than half of its total size (284 m2 of 484 m2) for nitrate removal alone
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