1,659 research outputs found
Development of a Pulse Shape Analysis for the CONUS Experiment
The CONUS experiment, using four 1 kg-sized point-contact high-purity germanium detectors (HPGe), aims to detect coherent elastic neutrino-nucleus scattering (CEνNS) in the fully coherent regime. It is located close to the reactor core of the nuclear power plant in Brokdorf, Germany. For the success of the experiment excellent background suppression is crucial. A new opportunity for further background reduction is the analysis of the pulse shape of each event. Depending on whether the incoming particle interacts in the fully depleted bulk region or in an outer layer of the Ge diode, the resulting pulse shapes are different. In this thesis, a technique will be presented to discriminate the different low energy interactions based on a rise time fit of their pulses. It will be shown that the rise time fit analysis can be used down to energies of ∼ 200 eV and that an additional background reduction of about 25 % in the region of interest for CEνNS is achievable. For this purpose, a new method will be presented to calculate the efficiencies of a pulse shape cut, including systematic uncertainties. The universality of the rise time fit is shown by demonstrating the feasibility of discriminating multi-site events at high energies
Prenatal Determinants of Early Behavioral and Cognitive Development: The Generation R Study
Child development is fascinating in its complexity and for more than 120 years
psychologists have applied scientific methods to its examination, but the concept of
child development did not receive much attention from philosophers during classical
antiquity and the Middle Ages (Oerter & Montada, 2002). Based on his analysis of
art work the historian Philippe Ariès (1962) assumed that the concept of childhood
did not exist in the medieval period and concluded that children were considered as
little adults. In the medieval period, most young people were apprentices, became
workers in the fields and normally entered the adult world very early in life (Ariès,
1962).
Very important for the emergence of the concept of child development were two
opposing philosophical views of human nature from the 17th and 18th century (De-
Hart, Sroufe, & Cooper, 2004). On the one hand, the English empiricist John Locke
(1632-1704) argued that at birth the mind of a child is tabula rasa, “a totally blank
slate to be written on by life’s experience” (DeHart et al., 2004). This blank slate view
suggests that differences among children can be explained in terms of differences in
their environments (Boyd & Bee, 2009). On the other hand, Jean Jacques Rousseau
(1712-1778) claimed that all human beings possess innate goodness and seek
out experiences that help them grow (Boyd & Bee, 2009). According to Rousseau,
child development unfolds naturally in positive ways as long as society allows it to do
so (Boyd & Bee, 2009). To this day, these two opposing views of human nature are
still reflected in the so-called nature-nurture debate addressing of how heredity and
environment influence development
Automated Reconstruction of Particle Cascades in High Energy Physics Experiments
We present a procedure for reconstructing particle cascades from event data
measured in a high energy physics experiment. For evaluating the hypothesis of
a specific physics process causing the observed data, all possible
reconstruction versions of the scattering process are constructed from the
final state objects. We describe the procedure as well as examples of physics
processes of different complexity studied at hadron-hadron colliders. We
estimate the performance by 20 microseconds per reconstructed decay vertex, and
0.6 kByte per reconstructed particle in the decay trees.Comment: 8 pages, 2 figures. Submitted to Computational Science & Discover
Recurrent shell infall events in a B0.5e star: HD 58978 1979-1988
Infall from the circumstellar envelope onto the bright B0.5 IVe star, HD 58978 was studied. The IUE data indicate that the star was surrounded by a low and moderately ionized circumstellar shell at least 12 times between 1979 and 1988. During 6 of these episodes, the signatures of cool circumstellar material were redshifted with respect to the photosphere by 20 to 80 km/sec. The data indicate that the transition from infall to minimal shell absorption can occur in under 10 days, and are consistent either with infall phases lasting up to 6 months, or with infall episodes shorter than 10 to 15 days. The long term behavior of the shell episodes is compared with variability in the stellar wind
Empowering victims of domestic violence in developing countries:The role of education and employment
Search for the magnetic field of the O7.5 III star xi Persei
Cyclical wind variability is an ubiquitous but as yet unexplained feature
among OB stars. The O7.5 III(n)((f)) star xi Persei is the brightest
representative of this class on the Northern hemisphere. As its prominent
cyclical wind properties vary on a rotational time scale (2 or 4 days) the star
has been already for a long time a serious magnetic candidate. As the cause of
this enigmatic behavior non-radial pulsations and/or a surface magnetic field
are suggested. We present a preliminary report on our attempts to detect a
magnetic field in this star with high-resolution measurements obtained with the
spectropolarimeter Narval at TBL, France during 2 observing runs of 5 nights in
2006 and 5 nights in 2007. Only upper limits could be obtained, even with the
longest possible exposure times. If the star hosts a magnetic field, its
surface strength should be less than about 300 G. This would still be enough to
disturb the stellar wind significantly. From our new data it seems that the
amplitude of the known non-radial pulsations has changed within less than a
year, which needs further investigation.Comment: 2 pages, 6 figures, contributed poster at IAU Symposium 259 "Cosmic
Magnetic Fields: from Planets, to Stars and Galaxies", Tenerife, Spain,
November 3-7, 200
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