Search results for "LIFETIME"
showing 10 items of 212 documents
Dependence of two-proton radioactivity on nuclear pairing models
2017
Sensitivity of two-proton emitting decay to nuclear pairing correlation is discussed within a time-dependent three-body model. We focus on the $^6$Be nucleus assuming $\alpha + p + p$ configuration, and its decay process is described as a time-evolution of the three-body resonance state. For a proton-proton subsystem, a schematic density-dependent contact (SDDC) pairing model is employed. From the time-dependent calculation, we observed the exponential decay rule of a two-proton emission. It is shown that the density dependence does not play a major role in determining the decay width, which can be controlled only by the asymptotic strength of the pairing interaction. This asymptotic pairin…
Effect of the linkage location in double branched organic dyes on the photovoltaic performance of DSSCs
2015
Two novel double branched D–π–A organic dyes (DB dyes) are synthesized to investigate the influence of the linkage location in DB dyes on the performance of dye-sensitized solar cells (DSSCs), where phenothiazine is introduced as a donor, thiophene–benzotriazole unit as the π-bridge and cyanoacrylic acid as the electron-acceptor. The photophysical, electrochemical and photovoltaic properties of the dyes are systematically investigated. The results show that the location of the linkage unit has a small effect on the physical and electrochemical properties of the dyes. However, when the dyes are applied in DSSCs, an obvious decline of short-circuit current (Jsc) and open-circuit voltage (Voc)…
Sociodemographic and behavioural correlates of lifetime number of sexual partners: findings from the English Longitudinal Study of Ageing.
2018
BackgroundNo current data are available on correlates of lifetime sexual partners at older ages. This study aimed to explore correlates of the lifetime number of sexual partners in a sample of older adults.MethodData were from 3054 men and 3867 women aged ≥50 years participating in the English Longitudinal Study of Ageing. Participants reported their lifetime number of sexual partners and a range of sociodemographic characteristics and health behaviours. Multivariable multinomial logistic regression was used to examine correlates of lifetime number of sexual partners, with analyses performed separately for men and women and weighted for non-response.ResultsYounger age, being separated/divor…
Global, regional, and country-specific lifetime risks of stroke, 1990 and 2016
2018
Background: The lifetime risk of stroke has been calculated in a limited number of selected populations. We sought to estimate the lifetime risk of stroke at the regional, country, and global level using data from a comprehensive study of the prevalence of major diseases.Methods: We used the Global Burden of Disease (GBD) Study 2016 estimates of stroke incidence and the competing risks of death from any cause other than stroke to calculate the cumulative lifetime risks of first stroke, ischemic stroke, or hemorrhagic stroke among adults 25 years of age or older. Estimates of the lifetime risks in the years 1990 and 2016 were compared. Countries were categorized into quintiles of the sociode…
Impact of Service Quality Dimensions on the Formation of Customer Value in B to B Services
2013
PurposeCustomer and value‐oriented business strategies are increasingly important in the context of business to business services. However, little is known about the construction of customer value of B to B services. Also the influences of specific dimensions of service quality on customer value are open to debate. This study aims to explore the construction of customer value of B to B services, and to examine how specific dimensions of service quality contribute to customer value.Design/methodology/approachThe research data consists of 90 questionnaires which were collected through the structured interview method among Finnish business organizations. Hypothesis testing was conducted throug…
Identifying potential sources of value in a packaging value chain
2013
Purpose – The purpose of this paper is to propose a process approach for identifying potential sources of customer value of a package in a packaging value chain and illustrate the approach through interview data. Design/methodology/approach – The proposed process approach is a synthesis of customer value theories presented in marketing literature and packaging functions presented in packaging-related literature. Packaging value chain members were interviewed to illustrate the critical packaging-related processes among their business processes and to reveal value in the level of packaging attributes and packaging functions/consequences in use situations. Findings – Interviews with packaging …
Charge injection and trapping at perovskite interfaces with organic hole transporting materials of different ionization energies
2019
The extraction of photogenerated holes from CH3NH3PbI3 is crucial in perovskite solar cells. Understanding the main parameters that influence this process is essential to design materials and devices with improved efficiency. A series of vacuum deposited hole transporting materials (HTMs) of different ionization energies, used in efficient photovoltaic devices, are studied here by means of femtosecond transient absorption spectroscopy. We find that ultrafast charge injection from the perovskite into the different HTMs (<100 fs) competes with carrier thermalization and occurs independently of their ionization energy. Our results prove that injection takes place from hot states in the valence…
Positronics of radiation-induced effects in chalcogenide glassy semiconductors
2015
Using As2S3 and AsS2 glasses as an example, the principal possibility of using positron annihilation spectroscopy methods for studying the evolution of the free volume of hollow nanoobjects in chalcogenide glassy semiconductors exposed to radiation is shown. The results obtained by measurements of the positron annihilation lifetime and Doppler broadening of the annihilation line in reverse chronological order are in full agreement with the optical spectroscopy data in the region of the fundamental absorption edge, being adequately described within coordination defect-formation and physical-aging models.
Optical and photovoltaic properties of indium selenide thin films prepared by van der Waals epitaxy
2001
Indium selenide thin films have been grown on p-type gallium selenide single crystal substrates by van der Waals epitaxy. The use of two crucibles in the growth process has resulted in indium selenide films with physical properties closer to these of bulk indium selenide than those prepared by other techniques. The optical properties of the films have been studied by electroabsorption measurements. The band gap and its temperature dependence are very close to those of indium selenide single crystals. The width of the fundamental transition, even if larger than that of the pure single crystal material, decreases monotonously with temperature. Exciton peaks are not observed even at low temper…
Particle Detectors made of High Resistivity Czochralski Grown Silicon
2004
We describe the fabrication process of fullsize silicon microstrip detectors processed on silicon wafers grown by magnetic Czochralski method. Defect analysis by DLTS spectroscopy as well as minority carrier lifetime measurements by µPCD method are presented. The electrical and detection properties of the Czochralski silicon detectors are comparable to those of leading commercial detector manufacturers. The radiation hardness of the Czochralski silicon detectors was proved to be superior to the devices made of traditional Float Zone silicon material.