Particle kinetic simulation of high altitude hypervelocity flight

In this grant period, the focus has been on the effects of thermo-chemical nonequilibrium in low-density gases, and on interactions between such gases and solid surfaces. Such conditions apply to hypersonic flows of re-entry vehicles, and to the expansion plumes of small rockets. Due to the nonequilibrium nature of these flows, a particle approach has been adopted. The method continues to undergo refinement and application to typical flows of interest. A number of studies have been performed for flows in thermo-chemical nonequilibrium. The effects of vibrational nonequilibrium on the rate of dissociation were studied for diatomic nitrogen. It was found that a new model reproduced the nonequilibrium behavior observed experimentally

Parameter-induced uncertainty quantification of soil N 2 O, NO and CO 2 emission from Höglwald spruce forest (Germany) using the LandscapeDNDC model

Assessing the uncertainties of simulation results of ecological models is becoming increasingly important, specifically if these models are used to estimate greenhouse gas emissions on site to regional/national levels. Four general sources of uncertainty effect the outcome of process-based models: (i) uncertainty of information used to initialise and drive the model, (ii) uncertainty of model parameters describing specific ecosystem processes, (iii) uncertainty of the model structure, and (iv) accurateness of measurements (e.g., soil-atmosphere greenhouse gas exchange) which are used for model testing and development. The aim of our study was to assess the simulation uncertainty of the process-based biogeochemical model LandscapeDNDC. For this we set up a Bayesian framework using a Markov Chain Monte Carlo (MCMC) method, to estimate the joint model parameter distribution. Data for model testing, parameter estimation and uncertainty assessment were taken from observations of soil fluxes of nitrous oxide (N2O), nitric oxide (NO) and carbon dioxide (CO2) as observed over a 10 yr period at the spruce site of the Höglwald Forest, Germany. By running four independent Markov Chains in parallel with identical properties (except for the parameter start values), an objective criteria for chain convergence developed by Gelman et al. (2003) could be used. Our approach shows that by means of the joint parameter distribution, we were able not only to limit the parameter space and specify the probability of parameter values, but also to assess the complex dependencies among model parameters used for simulating soil C and N trace gas emissions. This helped to improve the understanding of the behaviour of the complex LandscapeDNDC model while simulating soil C and N turnover processes and associated C and N soil-atmosphere exchange. In a final step the parameter distribution of the most sensitive parameters determining soil-atmosphere C and N exchange were used to obtain the parameter-induced uncertainty of simulated N2O, NO and CO2 emissions. These were compared to observational data of an calibration set (6 yr) and an independent validation set of 4 yr. The comparison showed that most of the annual observed trace gas emissions were in the range of simulated values and were predicted with a high certainty (Root-mean-squared error (RMSE) NO: 2.4 to 18.95 g N ha−1 d−1, N2O: 0.14 to 21.12 g N ha−1 d−1, CO2: 5.4 to 11.9 kg C ha−1 d−1). However, LandscapeDNDC simulations were sometimes still limited to accurately predict observed seasonal variations in fluxes

Electron holes in a regularized kappa background

The pseudopotential method is used to derive electron hole structures in a suprathermal plasma with a regularized κ probability distribution function background. The regularized character allows the exploration of small κ values beyond the standard suprathermal case for which κ > 3/2 is a necessary condition. We found the nonlinear dispersion relation yielding the amplitude of the electrostatic potential in terms of the remaining parameters, in particular the drift velocity, the wavenumber and the spectral index. Periodic, solitary wave, drifting and non-drifting solutions have been identified. In the linear limit, the dispersion relation yields generalized Langmuir and electron acoustic plasma modes. Standard electron hole structures are regained in the κ 1 limit

International Trade: Smarten up to talk the talk

International trade is currently under fire from many sides. Protectionist trade policies are on the rise, putting an end to the decade-long march of free trade. Making sense of the daily headlines and having an informed opinion on your own has rarely been more important than it is now. Our work aims to explain the driving forces behind international trade, its history, how it shaped the world, its economic models, issues ranging from job losses to the environment and why eating kangaroos is better than buying local. We summarize the most important academic literature on these topics in a non-technical, educational manner. If the readers conclude that our report has been useful in forming their own views on the pros and cons of international trade and that they can `talk the talk', we are gratified with the fruit of our work

Electron Holes in a Regularized Kappa Background

The pseudopotential method is used to derive electron hole structures in a suprathermal plasma having a regularized $\kappa$ probability distribution function background. The regularized character allows the exploration of small $\kappa$ values beyond the standard suprathermal case, for which $\kappa > 3/2$ is a necessary condition. We have found the nonlinear dispersion relation yielding the amplitude of the electrostatic potential in terms of the remaining parameters, in particular the drift velocity, the wavenumber and the spectral index. Periodic, solitary wave, drifting and non-drifting solutions have been identified. In the linear limit, the dispersion relation yields generalized Langmuir and electron acoustic plasma modes. Standard electron hole structures are regained in the $\kappa \gg 1$ limit

International Trade: Smarten up to talk the talk

International trade is currently under fire from many sides. Protectionist trade policies are on the rise, putting an end to the decade-long march of free trade. Making sense of the daily headlines and having an informed opinion on your own has rarely been more important than it is now. Our work aims to explain the driving forces behind international trade, its history, how it shaped the world, its economic models, issues ranging from job losses to the environment and why eating kangaroos is better than buying local. We summarize the most important academic literature on these topics in a non-technical, educational manner. If the readers conclude that our report has been useful in forming their own views on the pros and cons of international trade and that they can `talk the talk', we are gratified with the fruit of our work

Prevalence of Cardiovascular Disease Risk Factors in Migrants Participating in the PEP Family Heart Study, Nuremberg

Objectives: The aim of this study was to assess the prevalence of cardiovascularrisk factors in adults and their children from the 3 majorgroups of migrants participating in the PEP Family Heart Study 11 andto compare the cardio-metabolic risk profiles between migrants andGerman participants.Methods: In this community-based cross-sectional study, anthropometricdata, blood pressure and lipid profiles of migrants (480 children,363 adults) from Turkey (TUR), Eastern Europe (EEU) and Germanimmigrants from the former Soviet Union (GFSU) were comparedwith age- and gender adjusted German (GER) residents (3253 children,2491 adults).Results: The profile of risk factors differed considerably regardingspecificity and frequency. The prevalence of ≥3 risk factors was asfollows: in GFSU men 62%, women 36%, boys 19% and girls 17%; inTUR men 57%, women 30%, 15% boys and 6% girls; in GER men48%, women 19%, boys 4% and girls 6%; for EEU men 38%, women25% and 0% in children. No risk factor was present in GFSU men13%, women 25%, boys 38% and girls 42%; TUR men 13%, women28%, boys 27% and girls 22 %; GER men16%, women 45%, boys 46%and girls 41%; EEU men 17%, women 42 %, boys 29% and girls 27%.About 50% of the adults from Turkey and Eastern Europe were currentsmokers and one third of women and half of men from these twocountries were overweight.Conclusions: The implementation of primary care measures for theprevention of cardiovascular disease in migrants is necessary, and itshould consider the ethnic differences and the heterogeneous risk profile

Regional assessment and uncertainty analysis of carbon and nitrogen balances at cropland scale using the ecosystem model LandscapeDNDC

The assessment of cropland carbon and nitrogen (C and N) balances plays a key role in identifying cost-effective mitigation measures to combat climate change and reduce environmental pollution. In this paper, a biogeochemical modelling approach is adopted to assess all C and N fluxes in a regional cropland ecosystem of Thessaly, Greece. Additionally, the estimation and quantification of the modelling uncertainty in the regional inventory are realized through the propagation of parameter distributions through the model, leading to result distributions for modelling estimations. The model was applied to a regional dataset of approximately 1000 polygons, deploying model initializations and crop rotations for the five major crop cultivations and for a time span of 8 years. The full statistical analysis on modelling results (including the uncertainty ranges given as ± values) yields for the C balance carbon input fluxes into the soil of 12.4 ± 1.4 t C ha$^{−1}$ yr$^{−1}$ and output fluxes of 11.9 ± 1.3 t C ha$^{−1}$ yr$^{−1}$, with a resulting average carbon sequestration of 0.5 ± 0.3 t C ha−1 yr$^{−1}$. The averaged N influx was 212.3 ± 9.1 kg N ha$^{−1}$ yr$^{−1}$, while outfluxes of 198.3 ± 11.2 kg N ha$^{−1}$ yr$^{−1}$ were estimated on average. The net N accumulation into the soil nitrogen pools was estimated to be 14.0 ± 2.1 kg N ha$^{−1}$ yr$^{−1}$. The N outflux consists of gaseous N fluxes composed of N$_2$O emissions of 2.6 ± 0.8 kg N$_2$O–N ha$^{−1}$ yr$^{−1}$, NO emissions of 3.2 ± 1.5 kg NO–N ha$^{−1}$ yr$^{−1}$, N$_2$ emissions of 15.5 ± 7.0 kg N$_2$–N ha$^{−1}$ yr$^{−1}$ and NH$_3$ emissions of 34.0 ± 6.7 kg NH$_3$–N ha$^{−1}$ yr$^{−1}$, as well as aquatic N fluxes (only nitrate leaching into surface waters) of 14.1 ± 4.5 kg NO$_3$–N ha$^{−1}$ yr$^{−1}$ and N fluxes of N removed from the fields in yields, straw and feed of 128.8 ± 8.5 kg N ha$^{−1}$ yr$^{−1}$

How do Kosovar and Albanian consumers perceive food quality and safety in the dairy sector?

Kosovo and Albania, in a manner similar to other Western Balkan countries, face serious challenges in relation to national food safety and control in terms of legislation, infrastructure, institutional capacity and private investments. Consequently, food safety is a major concern for consumers in this region. The objective of this study was to gain a better understanding of consumer perspectives on food safety and quality. Two surveys, one with consumers in Prishtina and one in Tirana, targeted more than 600 consumers. Despite the prevalent problems with food safety, Kosovars perceive domestic dairy products as significantly better than Albanians do when compared with imported food products. Conversely, Albanian consumers use food safety- and quality-related information about cheese and milk more frequently. The most frequently used safety and quality cues for both samples are expiry date, domestic and local origin and brand reputation. Food safety certificates are used by Albanians more often than by Kosovars, and international food standards such as ISO, HACCP or Global GAP are mostly unknown to both consumer groups