37 research outputs found
The WITCH experiment: Acquiring the first recoil ion spectrum
The standard model of the electroweak interaction describes beta-decay in the
well-known V-A form. Nevertheless, the most general Hamiltonian of a beta-decay
includes also other possible interaction types, e.g. scalar (S) and tensor (T)
contributions, which are not fully ruled out yet experimentally. The WITCH
experiment aims to study a possible admixture of these exotic interaction types
in nuclear beta-decay by a precise measurement of the shape of the recoil ion
energy spectrum. The experimental set-up couples a double Penning trap system
and a retardation spectrometer. The set-up is installed in ISOLDE/CERN and was
recently shown to be fully operational. The current status of the experiment is
presented together with the data acquired during the 2006 campaign, showing the
first recoil ion energy spectrum obtained. The data taking procedure and
corresponding data acquisition system are described in more detail. Several
further technical improvements are briefly reviewed.Comment: 11 pages, 6 figures, conference proceedings EMIS 2007
(http://emis2007.ganil.fr), published also in NIM B:
doi:10.1016/j.nimb.2008.05.15
First detection and energy measurement of recoil ions following beta decay in a Penning trap with the WITCH experiment
The WITCH experiment (Weak Interaction Trap for CHarged particles) will
search for exotic interactions by investigating the beta-neutrino angular
correlation via the measurement of the recoil energy spectrum after beta decay.
As a first step the recoil ions from the beta-minus decay of 124In stored in a
Penning trap have been detected. The evidence for the detection of recoil ions
is shown and the properties of the ion cloud that forms the radioactive source
for the experiment in the Penning trap are presented.Comment: 9 pages, 6 figures (9 figure files), submitted to European Physical
Journal
The WITCH experiment: completion of a set-up to investigate the structure of weak interactions with a Penning trap
The WITCH experiment aims to study a possible admixture of a scalar or tensor
type interaction in beta decay by determining the beta-neutrino angular
correlation from the shape of the recoil energy spectrum. The installation
period was completed and intensive commissioning of the set-up was performed
already. The lay-out of the WITCH set-up and results of commissioning tests
performed until now are described here, showing that the full set-up up to the
spectrometer is now operational, although several efficiencies are still to be
improved. Due to its feature of being able to measure the energy spectrum for
recoil ions, the WITCH experiment also opens possibilities for other
observables.Comment: 31 pages, 18 figures. International Journal of Mass Spectrometry, in
pres
Progress at the WITCH experiment
The WITCH-experiment will measure the energy spectrum of the recoiling daughter ions in -decay to search for non-standard scalar and tensor type interaction. To facilitate this a Penning trap is used to store the radioactive ions. Thus the recoil ions can leave the source without any energy loss and their energy can be probed by the subsequent retardation spectrometer. The experiment is being set up at present at ISOLDE/CERN. The principle and the status of the WITCH-experiment will be presented. (12 refs)
On the Nature of the party statute
国内学者对于“党内法规”的研究相对完善,在不同角度分别给出了不同的定义,综合的来看我们可以将“党内法规”这一个宏观概念诠释为包含了法律、纪律、行政规范以及制度建设等多个方面。在本文的研究中我们应该严谨地来探讨“党内法规”的本意,并从中找到我们是在什么意义上或什么层面上使用这个概念。这样便于我们有效地进行有关的科学探讨。 在当前理论研究中,学术界对于“党内法规”这个提法是有一定争议的。有学者认为,“由于‘党内法规’这一提法不能准确地将党的规章制度与国家法律法规相区别,建议用‘党的纪律’代替‘党内法规’的相关定义,此种提法是相对准确的。同时,部分研究人员从法学的角度给出了不同的定义,其认为法规与..." Party regulations," the word as a concept , there are many inherent meanings , including party discipline , party system , the party's legal . From the party's history, " the party regulations," often from a different angle or significance used up . As an academic discussion , we should rigorously to explore the "inner regulations," the intention , and find meaning in what we are or what level t...学位:法律硕士院系专业:法学院法律系_法律硕士(JM)学号:X200812014
Seismic resistance of traditional timber-frame hımış
Hımış structures have hardly ever found as extensive a role as other traditional timber housing, such as those originating from Japan or Central Europe, within the wide discourse on the seismic performance of timber-frame architecture that has gained significant momentum in the last few decades owing to advancing testing technologies. While the hımış construction technique was perhaps not born as a result of a conscious search for a seismically resistant building form, it was soon widely appreciated for its structural features advantageous under seismic loading - especially from the sixteenth century when it has become a well-established construction technique in part of the Balkans and in today’s Turkey. Despite widely available anecdotal information based on post-disaster studies regarding its performance under earthquakes, robust quantitative data on the seismic behaviour of these structures were practically non-existent until quite recently, and are still somewhat limited. However, we are now able to confirm that hımış constructions do have intrinsic qualities that are very beneficial under seismic action. This paper aims to make a brief review of the current state of our knowledge on structural performance of hımış buildings under earthquake loading, with specific emphasis on infill/cladding techniques, connection details and energy dissipation characteristics
Specific gyrA gene mutations predict poor treatment outcome in MDR-TB
YesMutations in the gyrase genes cause fluoroquinolone resistance in Mycobacterium tuberculosis. However, the predictive value of these markers for clinical outcomes in patients with MDR-TB is unknown to date. The objective of this study was to determine molecular markers and breakpoints predicting second-line treatment outcomes in M. tuberculosis patients treated with fourth-generation fluoroquinolones.
We analysed treatment outcome data in relation to the gyrA and gyrB sequences and MICs of ofloxacin, gatifloxacin and moxifloxacin for pretreatment M. tuberculosis isolates from 181 MDR-TB patients in Bangladesh whose isolates were susceptible to injectable drugs.
The gyrA 90Val, 94Gly and 94Ala mutations were most frequent, with the highest resistance levels for 94Gly mutants. Increased pretreatment resistance levels (>2 mg/L), related to specific mutations, were associated with lower cure percentages, with no cure in patients whose isolates were resistant to gatifloxacin at 4 mg/L. Any gyrA 94 mutation, except 94Ala, predicted a significantly lower proportion of cure compared with all other gyrA mutations taken together (all non-94 mutants + 94Ala) [OR = 4.3 (95% CI 1.4-13.0)]. The difference in treatment outcome was not explained by resistance to the other drugs.
Our study suggests that gyrA mutations at position 94, other than Ala, predict high-level resistance to gatifloxacin and moxifloxacin, as well as poor treatment outcome, in MDR-TB patients in whom an injectable agent is still effective