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Compared to traditional pn-junction photovoltaics, hot carrier solar cells offer potentially higher efficiency by extracting work from the kinetic energy of photogenerated 'hot carriers' before they cool to the lattice temperature. Hot carrier solar cells have been demonstrated in high-bandgap ferroelectric insulators and GaAs/AlGaAs heterostructures, but so far not in low-bandgap materials, where
I backspegeln är det ofta enkelt att konstatera att vetenskapliga discipliner förändrats. Teoribildningar, forskningsfrågor och analysmetoder som i ett tidigare skede varit centrala, har minskat i bruk eller försvunnit helt, samtidigt som nya har tillkommit. Frågan om en förändring ägt rum kan därför upplevas som relativt enkel att besvara. Men varför, hur och när ett vetenskapligt fält utvecklas
Several attempts have been made to model chronic myeloid leukemia (CML) in a xenograft setting but expansion of human myeloid cells in immunodeficient mice has proven difficult to achieve. Lack of cross-reacting cytokines in the microenvironment of the mice has been proposed as a potential reason. In this study we have used NOD/SCID IL2–receptor gamma deficient mice expressing human SCF, IL-3 and
This study investigates volatility spillovers to electric power from large exogenous shocks in the prices of gas, coal, and carbon emission allowances in the German energy market. Our sample ranges from 2008 to 2016 and covers periods of different market conditions. We use a general VAR-BEKK model and the volatility impulse response function methodology to analyze and evaluate the spillover effect
Despite the important medical implications, it is currently an open task to find optical non-invasive techniques that can image deep organs in humans. Addressing this, photo-acoustic tomography (PAT) has received a great deal of attention in the past decade, owing to favorable properties like high contrast and high spatial resolution. However, even with optimal components PAT cannot penetrate beyo
Integration of a third component into a single-junction polymer solar cell (PSC) is regarded as an attractive strategy to enhance the performance of PSCs. Although binary all-polymer solar cells (all-PSCs) have recently emerged with compelling power conversion efficiencies (PCEs), the PCEs of ternary all-PSCs still lag behind those of the state-of-the-art binary all-PSCs, and the advantages of ter
Data are presented from two-dimensional (2-D) PAGE analysis of Mycobacterium tuberculosis strain Harlingen grown during aerobic and anaerobic culture, according to a modified Wayne dormancy model. M. tuberculosis cultures were grown to the transition point between exponential growth and stationary phase in the presence of oxygen (7 days) and then part of the cultures was shifted to anaerobic condi
Regime-based asset allocation has been shown to add value over rebalancing to static weights and, in particular, reduce potential drawdowns by reacting to changes in market conditions. The predominant approach in previous studies has been to specify in advance a static decision rule for changing the allocation based on the state of financial markets or the economy. In this article, model predictiv
Spatial models, such as the Besag, York and Mollie (BYM)model, have long been used in epidemiology and disease mapping. A commonproblem in these subjects is the modelling of number of disease eventsper region; here the BYM models provides a holistic framework for bothcovariates and dependencies between regions.We use these tools to assess the relative insurance risk associated withthe policyholderSpatial models, such as the Besag, York and Mollie (BYM)model, have long been used in epidemiology and disease mapping. A commonproblem in these subjects is the modelling of number of disease eventsper region; here the BYM models provides a holistic framework for bothcovariates and dependencies between regions.We use these tools to assess the relative insurance risk associated withthe policyholder
In this talk, model predictive control (MPC) is used to dynamically optimize an investment portfolio. Thepredictive control is based on multi-period forecasts of the mean and covariance of financial returns from amultivariate hidden Markov model with time-varying parameters. Estimation and forecasting are done using anonline expectation--maximization algorithm. There are computational advantages t
Multilevel Monte Carlo is a novel method for reducing the computational costwhen computing conditional expectations of stochastic processes. This paper considersthe transition density for diffusion processes. It is known that the transitiondensity can be written as an expectation by utilizing the law of total probabilitycombined with the Markov property. This idea is combined with the multilevelMoMultilevel Monte Carlo is a novel method for reducing the computational cost when computing conditional expectations of stochastic processes. This paper considers the transition density for diffusion processes. It is known that the transition density can be written as an expectation by utilizing the law of total probability combined with the Markov property. This idea is combined with the multilev
Rail transport is an environmentally responsible approach and traffic is expected to increase in the coming decades. Little is known about the implications for quality of life of populations living close to railways. This study explores the way in which vibrations from rail are perceived and described by these populations. The study took place in the Västra Götaland and Värmland regions of Sweden.
This chapter traces the long-run development of Genuine Savings (GS) using a panel of eleven countries during the twentieth century. This panel covers a number of developed countries (Great Britain, Germany,Switzerland, France, the US, and Australia) as well as a set of resource-abundant countries in Latin America(Argentina, Brazil, Chile, Colombia, and Mexico). These countries represent approxima
A low-latency and area-efficient FFT/IFFT scheme is presented. The main idea is to utilize OFDM guard bands to reduce the operation counts and processing time, which results in 42% latency reduction compared to the reported pipelined schemes. To realize this idea, a modified pipelined architecture and an efficient data scheduling scheme are proposed. Furthermore, the proposed architecture is scala
We have studied an X-ray switch based on a gold coated indium antimonide crystal using time-resolved X-ray diffraction and demonstrated that the switch could reduce the pulse duration of a 100 ps X-ray pulse down to 20 ps with a peak reflectivity of 8%. We have used a dynamical diffraction code to predict the performance of the switch, which was then confirmed experimentally. The experiment was ca
A flying animal can minimize its energy consumption by choosing an optimal flight speed depending on the task at hand. Choice of flight speed can be predicted by modelling the aerodynamic power required for flight, and this tool has previously been used extensively in bird migration research. For insects, however, it is uncertain whether any of the commonly used power models are useful, as insects
Many animals engage in contests with conspecifics for access to resources. Understanding which resources individuals are contesting for, and what influences the outcome is central to our understanding of contest behaviour. We initially observed female bees of the genus Tetralonia (sp. n.) aggressively competing for access to burrows in the ground, without any clear indication of exactly which reso
The aim of model calibration is to estimate unique parameter values from available experimental data, here applied to a biocatalytic process. The traditional approach of first gathering data followed by performing a model calibration is inefficient, since the information gathered during experimentation is not actively used to optimize the experimental design. By applying an iterative robust model-
Background. Exposure to lead (Pb) in environmental and occupational settings continues to be a serious public health problem and may pose an elevated risk of genetic damage. Objectives. The aim of this study was to assess the level of oxidative stress and DNA damage in subjects occupationally exposed to lead. Material and methods. We studied a population of 78 male workers exposed to lead in a lea
