Search results for "CAPTURE"
showing 10 items of 463 documents
Comparative Analysis of Nuclear Matrix Elements of 0νβ+β+ Decay and Muon Capture in 106Cd
2021
Comparative analyses of the nuclear matrix elements (NMEs) related to the 0νβ+β+ decay of 106Cd to the ground state of 106Pd and the ordinary muon capture (OMC) in 106Cd are performed. This is the first time the OMC NMEs are studied for a nucleus decaying via positron-emitting/electron-capture modes of double beta decay. All the present calculations are based on the proton-neutron quasiparticle random-phase approximation with large no-core single-particle bases and realistic two-nucleon interactions. The effect of the particle-particle interaction parameter gpp of pnQRPA on the NMEs is discussed. In the case of the OMC, the effect of different bound-muon wave functions is studied. peerRevie…
Ordinary Muon Capture on 136Ba : Comparative Study Using the Shell Model and pnQRPA
2023
In this work, we present a study of ordinary muon capture (OMC) on 136136Ba, the daughter nucleus of 136136Xe double beta decay (DBD). The OMC rates at low-lying nuclear states (below 1 MeV of excitation energy) in 136136Cs are assessed by using both the interacting shell model (ISM) and proton–neutron quasiparticle random-phase approximation (pnQRPA). We also add chiral two-body (2BC) meson-exchange currents and use an exact Dirac wave function for the captured s-orbital muon. OMC can be viewed as a complementary probe of the wave functions in 136136Cs, the intermediate nucleus of the 136136Xe DBD. At the same time, OMC can be considered a powerful probe of the effective values of weak axi…
The Hamburg/ESO R-process Enhanced Star survey (HERES)
2004
We report on a dedicated effort to identify and study metal-poor stars strongly enhanced in r-process elements ([r/Fe] > 1 dex; hereafter r-II stars), the Hamburg/ESO R-process Enhanced Star survey (HERES). Moderate-resolution (~2A) follow-up spectroscopy has been obtained for metal-poor giant candidates selected from the Hamburg/ESO objective-prism survey (HES) as well as the HK survey to identify sharp-lined stars with [Fe/H] < -2.5dex. For several hundred confirmed metal-poor giants brighter than B~16.5mag (most of them from the HES), ``snapshot'' spectra (R~20,000; S/N~30 per pixel) are being obtained with VLT/UVES, with the main aim of finding the 2-3% r-II stars expected to be a…
Are habitat loss, predation risk and climate related to the drastic decline in a Siberian flying squirrel population? A 15 year study
2014
To devise effective conservation actions, it is important to know which factors are associated with the population parameters of a declining population. Using mark–recapture methods, we estimated the annual population size, growth rate and survival probability of an ear-tagged flying squirrel population over a 15-year period in a 4,500 ha study area in western Finland. The species is considered vulnerable, but detailed knowledge concerning population sizes or trends is lacking. The population parameters and changes therein were regressed against habitat availability, an indicator of predation pressure, and mean winter temperature (an indicator of climate change), to reveal potential reasons…
The temporal variation in Siberian flying squirrel (Pteromys volans) population size
2011
Human land use causes declines of natural populations, for example, by loss of habitat area. Additionally, habitat fragmentation can cause the population size to decline more than is expected based on the area lost. Some ecological processes, such as demographic stochasticity and Allee effect, can expose already small populations to further decline. The endangered Siberian flying squirrel (Pteromys volans) has suffered from intensive forestry in Finland. In this thesis I estimated the size and growth rate of a local flying squirrel population living in nest boxes in Alavus using 15-year mark-recapture data. I regressed the estimated population size against habitat availability to detect rel…
Beta-decay studies for applied and basic nuclear physics
2020
In this review we will present the results of recent beta-decay studies using the total absorption technique that cover topics of interest for applications, nuclear structure and astrophysics. The decays studied were selected primarily because they have a large impact on the prediction of a) the decay heat in reactors, important for the safety of present and future reactors and b) the reactor electron antineutrino spectrum, of interest for particle/nuclear physics and reactor monitoring. For these studies the total absorption technique was chosen, since it is the only method that allows one to obtain beta decay probabilities free from a systematic error called the Pandemonium effect. The me…
Is a seminar based on student-created screen capture videos a meaningful way of learning?
2008
We ran a problem-based seminar with screen capture videos. The students worked in small groups of two or three students or they completed the coursework individually. In this seminar the students had a workspace in the Optima environment for publishing their coursework videos. At the final phase of the course the students were expected to familiarize themselves with the presentations of other groups. In this paper we analyze the benefit of our problem-based coursework on the web by comparing the different phases of it. After each phase the students were expected to analyze the benefit of it for their learning. peerReviewed
High-Resolution 3-D CZT Drift Strip Detectors for Prompt Gamma Ray and Neutron Detection in BNCT
2021
Spectroscopic imagers based on high-Z and wide-bandgap compound semiconductor detectors are widely proposed for the detection of prompt gamma rays in boron neutron capture therapy (BNCT). BNCT is a therapy based on the neutron capture reaction 10B (n,α)7Li. To perform a real-time monitoring of the spatial distribution of 10B during the treatments, the detection of the prompt gamma rays (478 keV), produced by the 7Li recoil nuclei, can be helpful. In this work, we presented the potentialities of new high-resolution CZT drift strip detectors, recently developed by our group, for BNCT measurements. The detectors, exploiting the analysis of the collected-induced charge pulses from anodes, catho…
Transformative direction of innovation and measurement of uncaptured GDP in the digital economy
2017
The Internet has dramatically changed business dynamics and our daily lives by providing extraordinary services and welfare never anticipated before. However, productivity in industrialized countries has confronted an apparent decline. The ICT advanced firms and countries are suffering with low marginal productivity of their ICT investments. This reveals the two-faced nature of ICT and productivity paradox in the digital economy. With the progression of technology and transition from commodity- oriented to information society, the consumers’ preferences are believed to be shifted beyond economic value. The digitization has promoted the free and un- monetized consumption of digital goods and…
Participation in Social Media: Studying Explicit and Implicit Forms of Participation in Communicative Social Networks
2016
The diverse forms of participation in social media raise many methodological and ethical issues that should be acknowledged in research. In this paper, participation in social media is studied by utilising the framework of explicit and implicit participation. The focus is on the communicative and communal aspects of social media. The aim of the paper is to promote the reconsideration of what constitutes participation when online users create connections rather than content. The underlying argument is that research on social media and the development of methods should concentrate more on implicit forms of participation.