39 research outputs found
Outlook of solar energy in Europe based on economic growth characteristics
Solar power production in Europe has raised from about 130 MW to 110 GW of installed capacity (corresponding to 90 GWh to 120 TWh in annual electricity generation) during the present century. Together with wind power, it constitutes the largest growth within renewable energy sources in the last decades. At present however, clear signs of saturation can be observed in the leading areas of solar power in Europe. Here, the development of solar power in Europe is analysed and, for the three leading countries (Germany, Italy, Spain) a logistic growth path at the national level and a proportionality between saturation level of the growth curve of each country and its gross domestic product (GDP) is found. The sum of the next three countries (France, UK, Belgium) is well described by a logistic path with a time offset relative to the first group of three, and the sum of the two logistic paths, representing in total about 85% of European solar power production, describes the growth pattern in the corresponding area very well. Based on this, an estimate of a future saturation level for solar power in Europe is obtained by extrapolation. Finally, a model based on logistic growth patterns and learning curves that links solar power production data to investment data, is proposed. The proposed model is validated and calibrated on historical European data and extrapolated into the future. In a future scenario where European investments continue to decrease, a saturation level that is fully in line with our GDP based 200 TWh/y estimate is found and the application of the findings is discussed in a global context
High-order photoelectron holography in the midinfrared-wavelength regime
We study the dynamical photoelectron holography of an excited hydrogen atom with a strong midinfrared laser field using numerical solutions of the three-dimensional time-dependent Schr\uf6dinguer equation. A clear holographic interference pattern of first and high order (hologram) is recorded in the two-dimensional (2D) momentum distribution of the photoelectron. The patterns are well reproduced by additional quantitative calculations based on the Lippmann-Schwinger equation. Here, the high-order interference effect is linked to the multsicattering of low-momentum electrons driven by the midinfrared laser field prior to ejection. The phenomenon manifests by low-momentum structures in 2D momentum distributions and is found to be sensitive to the change of the optical carrier-envelope phase (CEP). By analyzing the temporal evolution of the buildup of the hologram, we show that this sensitivity results from the birth time of the continuum wave packet with an offset in time during the subcycle dynamics, thus encoding information about the ionization mechanism which is mapped into the CEP-resolved 2D momentum distributions and angle-resolved photoelectron spectra. It is indeed an indicator that the ejected electrons exhibit a memory of their birth-time. These findings suggest that the CEP-resolved photoelectron holography serves as a tool for a direct measurement of attosecond dynamics. Furthermore, the effects due to such multiple scattering electron paths can be used to design new atom interferometers to highlight mechanisms that require higher accuracy
Femtosecond-pulse-train ionization of Rydberg wave packets
We calculate, based on first-order perturbation theory, the total and differential ionization probabilities from a dynamic periodic Rydberg wave packet of a given n-shell exposed to a train of femtosecond laser pulses. The total probability is shown to depend crucially on the laser repetition rate: For certain frequencies the ionization probability vanishes, while for others it becomes very large. The origin of this effect is the strong dependence of the ionization probability on the Stark quantum number. Correspondingly, the angular electronic distribution also changes significantly with the increasing number of pulses for certain repetition rates.publishedVersio
Antibiotic-loaded bone cement in prevention of periprosthetic joint infections in primary total knee arthroplasty: A register-based multicentre randomised controlled non-inferiority trial (ALBA trial)
Introduction The current evidence on the efficacy of antibiotic-loaded bone cement (ALBC) in reducing the risk of periprosthetic joint infections (PJI) after primary joint reconstruction is insufficient. In several European countries, the use of ALBC is routine practice unlike in the USA where ALBC use is not approved in low-risk patients. Therefore, we designed a double-blinded pragmatic multicentre register-based randomised controlled non-inferiority trial to investigate the effects of ALBC compared with plain bone cement in primary total knee arthroplasty (TKA).
Methods and analysis A minimum of 9,172 patients undergoing full-cemented primary TKA will be recruited and equally randomised into the ALBC group and the plain bone cement group. This trial will be conducted in Norwegian hospitals that routinely perform cemented primary TKA. The primary outcome will be risk of revision surgery due to PJI at 1-year of follow-up. Secondary outcomes will be: risk of revision due to any reason including aseptic loosening at 1, 6, 10 and 20 years of follow-up; patient-related outcome measures like function, pain, satisfaction and health-related quality of life at 1, 6 and 10 years of follow-up; risk of changes in the microbial pattern and resistance profiles of organisms cultured in subsequent revisions at 1, 6, 10 and 20 years of follow-up; cost-effectiveness of routine ALBC versus plain bone cement use in primary TKA. We will use 1:1 randomisation with random permuted blocks and stratify by participating hospitals to randomise patients to receive ALBC or plain bone cement. Inclusion, randomisation and follow-up will be through the Norwegian Arthroplasty Register.
Ethics and dissemination The trial was approved by the Western Norway Regional Committees on Medical and Health Research Ethics (reference number: 2019/751/REK vest) on 21 June 2019. The findings of this trial will be disseminated through peer-reviewed publications and conference presentations.
Trial registration number NCT04135170.publishedVersio
New relative intensity ambulatory accelerometer thresholds for elderly men and women: the Generation 100 study
Relationship between freight accessibility and logistics employment in US counties
This paper analyzes the relationship between freight accessibility and logistics employment in the US. It develops an accessibility measure relevant for logistics companies based on a gravity model. This allows for an analysis of the accessibility of US counties focusing on four different modes of transportation: road, rail, air, and maritime. Using a Partial Least Squares model, these four different freight accessibility measures are combined into two constructs, continental and intercontinental freight accessibility, and related to logistics employment. Results show that highly accessible counties attract more logistics employment than other counties. The analyses show that it is very important to control for the effect of the county population on both freight accessibility and logistics employment. While county population explains the most variation in the logistics employment per county, there is a significant relationship between freight accessibility and logistics employment, when controlling for this effect
Measuring the free fall of antihydrogen
After the first production of cold antihydrogen by the ATHENA and ATRAP experiments ten years ago, new second-generation experiments are aimed at measuring the fundamental properties of this anti-atom. The goal of AEGIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) is to test the weak equivalence principle by studying the gravitational interaction between matter and antimatter with a pulsed, cold antihydrogen beam. The experiment is currently being assembled at CERN's Antiproton Decelerator. In AEGIS, antihydrogen will be produced by charge exchange of cold antiprotons with positronium excited to a high Rydberg state (n > 20). An antihydrogen beam will be produced by controlled acceleration in an electric-field gradient (Stark acceleration). The deflection of the horizontal beam due to its free fall in the gravitational field of the earth will be measured with a moire deflectometer. Initially, the gravitational acceleration will be determined to a precision of 1%, requiring the detection of about 105 antihydrogen atoms. In this paper, after a general description, the present status of the experiment will be reviewed
Absolute and relative accelerometer thresholds for determining the association between physical activity and metabolic syndrome in the older adults: The Generation-100 study
Exploring the WEP with a pulsed cold beam of antihydrogen
The AEGIS experiment, currently being set up at the Antiproton Decelerator at CERN, has the objective of studying the free fall of antimatter in the Earth's gravitational field by means of a pulsed cold atomic beam of antihydrogen atoms. Both duration of free fall and vertical displacement of the horizontally emitted atoms will be measured, allowing a first test of the WEP with antimatter