1,333 research outputs found
A Large TPC Prototype with MPGD Readout: Status and Plans
The use of a TPC in future collider experiments needs significant research
and development. Within the EUDET program an infrastructure has been designed
and built to allow the efficient testing of TPC prototypes under realistic
conditions. The infrastructure consists of a test beam facility, located at
DESY Hamburg, and a multi-purpose TPC field cage.Comment: Conference LCES 2008, Chicag
Constraints from Neutrinoless Double Beta Decay
We examine the constraints from the recent HEIDELBERG-MOSCOW double beta
decay experiment. It leads us to the almost degenerate or inverse hierarchy
neutrino mass scenario. In this scenario, we obtain possible upper bounds for
the Majorana CP violating phase in the lepton sector by incorporating the data
from the neutrino oscillation, the single beta decay experiments, and from the
astrophysical observation. We also predict the neutrino mass that may be
measurable in the future beta decay experiments.Comment: 10 pages, 3 figure
The use of electrical discharge for ignition and control of combustion of solid propellants
As the first step of the study of the combustion control of solid propellants by electrical discharges, the effects of an arc discharge, which flows along the burning surface, on the burning rate and on the increase of enthalpy of the combustion product were investigated. For specially devised composite propellants, which are composed of Al and Teflon powders, it was shown that the combination can be controlled by an arc discharge; the combustion continues when the arc discharge is applied and is interrupted when the arc discharge breaks. In the present investigation, it was also shown that an arc discharge coupled with a high-frequency electrical discharge has potential as an effective ignition method for solid propellants. For the application of this type of combustion control to an ignitor for a solid propellant rocket motor or to a control rocket motor, this method lacks flexibility in the configuration scale and needs relatively high electric power at the present stage
Study for re-ASR behaviour of recycled concrete using ASR generated concrete and considering countermeasure technology
It is predicted that the concrete volume to be discarded will increase due to the renewal of the concrete structures and the increase in the returned concrete from construction site. The use of this concrete block as recycled aggregate is very important in terms of sustainability. However, recycled aggregate concrete is difficult to use due to large problems such as drying shrinkage and freeze-thaw action. On the other hand, the aggregate used for the raw concrete is often unknown, suggesting the danger of ASR. There is no previous research about what kind of danger is caused when an aggregate having an ASR risk is used as a recycled aggregate. Therefore, in this study, recycled aggregate was made from raw concrete where ASR occurred, after that recycled concrete was manufactured using this aggregate. After this, ASR tests were conducted again for the recycled concrete. In addition, we examined whether recycled concrete using aggregates with properties improved by using the previously reported carbonation technique could be an ASR countermeasure technology. As a result, it was found that the recycled concrete using the ASR-generated raw concrete as aggregate can suppress ASR by using recurring ASR aggregate treated by carbonation technology
Universal Texture of Quark and Lepton Mass Matrices
Against the conventional picture that the mass matrix forms in the quark
sectors will take somewhat different structures from those in the lepton
sectors, a possibility that all the mass matrices of quarks and leptons have
the same form as in the neutrinos is investigated. For the lepton sectors, the
model leads to a nearly bimaximal mixing with the prediction
|U_{e3}|^2=m_e/2m_\mu=0.0024 and \tan^2\theta_{sol} \simeq m_{\nu 1}/m_{\nu 2},
and so on. For the quark sectors, it can lead to reasonable values of the CKM
mixing matrix and masses: |V_{us}|\simeq \sqrt{m_d/m_s}, |V_{ub}| \simeq
|V_{cb}|\sqrt{m_u/m_c}, |V_{td}| \simeq |V_{cb}|\cdot |V_{us}|, and so on.Comment: 9 pages, Latex, talk given at The 4th workshop on "Neutrino
Oscillations and their Origin" (NOON2003) (Kanazawa, Japan, 10--14 Feb.
2002). To appear in the Proceeding
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