The Ionizing Radiation Interaction with Matter, the X-ray Computed Tomography Imaging, the Nuclear Medicine SPECT, PET and PET-CT Tomography Imaging

The mechanism of the ionizing radiation interaction with matter is described for heavy charged particles, electrons and photons. Those effects causing energy loss of the radiation with sequential effects of absorption or attenuation are presented. The features of some characteristic detector systems with the relative electronics and the data acquisition system (DAQ) are presented. Those detectors are related with the medical imaging sensor systems. The characteristics of the medical imaging process of the X-ray and nuclear imaging with SPECT, PET and the combination of PET-CT are presented. The computed X-ray tomography, called CT, and the nuclear medicine tomography are presented, implementing the most of the previous parts, as they are defined in PET and SPECT imaging plus the combination of PET with CT the PET-CT

Development and diffusion of building-integrated photovoltaics: analysing innovation dynamics in multi-sectoral technologies

The ongoing transformation of the energy system along a more sustainable trajectory requires advancements in a range of technological fields, as well as active involvement of different societal groups. Integration of photovoltaic (PV) systems in the built environment in particular is expected to play a crucial long-term role in the deployment of renewable energy technologies in urban areas, demanding the successful cooperation of planners, architects, engineers, scientists and users. The realisation of that technological change will require innovation at both an individual (within firms and organisations) and a collective (sector) level, giving rise to systemic approaches for its characterisation and analysis of its drivers. This study investigates the processes that either accelerate or hinder the development and diffusion of Building-Integrated PV (BIPV) applications into the market. Affected by developments in both the renewable energy and construction industries, the BIPV innovation system is a multi-sectoral case that has been explored only partially up to now. Acknowledging the fact that drivers of innovation span the globalised BIPV supply chain, this research adopts both an international and a national spatial perspective focusing on the UK. The analysis is based on a novel analytical framework which was developed in order to capture innovation dynamics at different levels, including technological advancements within firms, competition and synergy with other emerging and established innovation systems and pressures from the wider socio-economic configuration. This hybrid functional framework was conceived by combining elements from three academic strands: Technological Innovation Systems, the Multi-Level Perspective and Business Studies. The empirical research is based on various methods, including desktop research, semi-structured interviews and in-depth firm-level case studies. A thorough market assessment provides the techno-economic background for the research. The hybrid framework is used as a guide throughout the empirical investigation and is also implemented in the analytical part of the study to organise and interpret the findings, in order to assess the overall functionality of the innovation system. The analysis has underlined a range of processes that affect the development and diffusion of BIPV applications including inherent technological characteristics, societal factors and wider transitions within the energy and construction sectors. Future approaches for the assessment and governance of BIPV innovation will need to address its hybrid character and disruptiveness with regards to incumbent configurations, in order to appreciate its significance over the short and long term. Methodological and conceptual findings show that the combination of insights from different analytical perspectives offers a broader understanding of the processes affecting innovation dynamics in emerging technologies. Different approaches can be used in tandem to overcome methodological weaknesses, provide different analytical perspectives and assess the performance of complex innovation systems, which may span multiple countries and sectors. By better reflecting complexities, tensions and synergies, the framework developed here offers a promising way forward for the analysis of emerging sustainable technologies

Study of Tau-pair Production in Photon-Photon Collisions at LEP and Limits on the Anomalous Electromagnetic Moments of the Tau Lepton

Tau-pair production in the process e+e- -> e+e-tau+tau- was studied using data collected by the DELPHI experiment at LEP2 during the years 1997 - 2000. The corresponding integrated luminosity is 650 pb^{-1}. The values of the cross-section obtained are found to be in agreement with QED predictions. Limits on the anomalous magnetic and electric dipole moments of the tau lepton are deduced.Comment: 20 pages, 9 figures, Accepted by Eur. Phys. J.

Energy dependence of Cronin momentum in saturation model for p+Ap+A and A+AA+A collisions

We calculate $\sqrt{s}$ dependence of Cronin momentum for $p+A$ and $A+A$ collisions in saturation model. We show that this dependence is consistent with expectation from formula which was obtained using simple dimentional consideration. This can be used to test validity of saturation model (and distinguish among its variants) and measure $x$ dependence of saturation momentum from experimental data.Comment: LaTeX2e, 12 pages, 8 figure

CP asymmetry in B→ϕKSB \to \phi K_S in a general two-Higgs-doublet model with fourth-generation quarks

We discuss the time-dependent CP asymmetry of decay $B \to \phi K_S$ in an extension of the Standard Model with both two Higgs doublets and additional fourth-generation quarks. We show that although the Standard Model with two-Higgs-doublet and the Standard model with fourth generation quarks alone are not likely to largely change the effective $\sin 2 \beta$ from the decay of $B \to \phi K_S$, the model with both additional Higgs doublet and fourth-generation quarks can easily account for the possible large negative value of $\sin 2 \beta$ without conflicting with other experimental constraints. In this model, additional large CP violating effects may arise from the flavor changing Yukawa interactions between neutral Higgs bosons and the heavy fourth generation down type quark, which can modify the QCD penguin contributions. With the constraints obtained from $b \to s \bar{s} s$ processes such as $B \to X_s \gamma$ and $\Delta m_{B_s^0}$, this model can lead to the effective $\sin 2 \beta$ to be as large as $- 0.4$ in the CP asymmetry of $B \to \phi K_S$.Comment: 13 pages, 5 figures, references added, to appear in Eur.Phys.J.

A Precise Measurement of the Tau Lifetime

The tau lepton lifetime has been measured with the e+e- -> tau+tau- events collected by the DELPHI detector at LEP in the years 1991-1995. Three different methods have been exploited, using both one-prong and three-prong tau decay channels. Two measurements have been made using events in which both taus decay to a single charged particle. Combining these measurements gave tau_tau (1 prong) = 291.8 +/- 2.3 (stat) +/- 1.5 (sys) fs. A third measurement using taus which decayed to three charged particles yielded tau_tau (3 prong) = 288.6 +/- 2.4 (stat) +/- 1.3 (sys) fs. These were combined with previous DELPHI results to measure the tau lifetime, using the full LEP1 data sample, to be tau_tau = 290.9 +/- 1.4 (stat) +/- 1.0 (sys) fs.Comment: 27 pages, 7 figure

Search for composite and exotic fermions at LEP 2

A search for unstable heavy fermions with the DELPHI detector at LEP is reported. Sequential and non-canonical leptons, as well as excited leptons and quarks, are considered. The data analysed correspond to an integrated luminosity of about 48 pb^{-1} at an e^+e^- centre-of-mass energy of 183 GeV and about 20 pb^{-1} equally shared between the centre-of-mass energies of 172 GeV and 161 GeV. The search for pair-produced new leptons establishes 95% confidence level mass limits in the region between 70 GeV/c^2 and 90 GeV/c^2, depending on the channel. The search for singly produced excited leptons and quarks establishes upper limits on the ratio of the coupling of the excited fermio

Search for lightest neutralino and stau pair production in light gravitino scenarios with stau NLSP

Promptly decaying lightest neutralinos and long-lived staus are searched for in the context of light gravitino scenarios. It is assumed that the stau is the next to lightest supersymmetric particle (NLSP) and that the lightest neutralino is the next to NLSP (NNLSP). Data collected with the Delphi detector at centre-of-mass energies from 161 to 183 \GeV are analysed. No evidence of the production of these particles is found. Hence, lower mass limits for both kinds of particles are set at 95% C.L.. The mass of gaugino-like neutralinos is found to be greater than 71.5 GeV/c^2. In the search for long-lived stau, masses less than 70.0 to 77.5 \GeVcc are excluded for gravitino masses from 10 to 150 \eVcc . Combining this search with the searches for stable heavy leptons and Minimal Supersymmetric Standard Model staus a lower limit of 68.5 \GeVcc may be set for the stau mas

Measurement of the Tau Lepton Polarisation at LEP2

A first measurement of the average polarisation P_tau of tau leptons produced in e+e- annihilation at energies significantly above the Z resonance is presented. The polarisation is determined from the kinematic spectra of tau hadronic decays. The measured value P_tau = -0.164 +/- 0.125 is consistent with the Standard Model prediction for the mean LEP energy of 197 GeV.A first measurement of the average polarisation Pτ of tau leptons produced in e + e − annihilation at energies significantly above the Z resonance is presented. The polarisation is determined from the kinematic spectra of tau hadronic decays. The measured value Pτ=−0.164±0.125 is consistent with the Standard Model prediction for the mean LEP energy of 197 GeV.A first measurement of the average polarisation P_tau of tau leptons produced in e+e- annihilation at energies significantly above the Z resonance is presented. The polarisation is determined from the kinematic spectra of tau hadronic decays. The measured value P_tau = -0.164 +/- 0.125 is consistent with the Standard Model prediction for the mean LEP energy of 197 GeV