Nonlinear Structure of the Diffusing Gas-Metal Interface in a Thermonuclear Plasma

This Letter describes the theoretical structure of the plasma diffusion layer that develops from an initially sharp gas-metal interface. The layer dynamics under isothermal and isobaric conditions is considered so that only mass diffusion (mixing) processes can occur. The layer develops a distinctive structure with asymmetric and highly nonlinear features. On the gas side of the layer the diffusion coefficient goes nearly to zero, causing a sharp “front,” or well defined boundary between mix layer and clean gas with similarities to the Marshak thermal waves. Similarity solutions for the nonlinear profiles are found and verified with full ion kinetic code simulations. A criterion for plasma diffusion to significantly affect burn is given.United States. Dept. of Energy (Contract DE-AC52-06NA25396)United States. Dept. of Energy. Office of Science (Contract DE-AC52-07NA27344

Using games for teaching crisis communication in higher education and training

© 2016 IEEE. Terror actions and catastrophes are frequently described in media. As more and more countries experience terror actions and natural disasters, there has been a greater focus on learning how to handle and to manage them. In Norway on the 22nd of July 2011, Anders Behring Breivik placed a bomb in a car that exploded near the Governmental Offices killing 8 persons. He went on to an island where there was a political camp for youths killing another 67. The rescue operations unveiled an unprepared task force. The Gjrv-report provide a massive critique towards the call out services [1]. This kicked off a major work on updating safety routines in all municipalities. The municipalities are now obliged to have a plan for crisis preparedness [2]. This again triggered the need for education within the area of crisis preparedness, crisis training and crisis management. Hedmark University of Applied Science now offers different study programs, including a BA within these areas. It is, however, very expensive to train realistically and the need for different approaches regarding training has been discussed. One of the solutions that the University is currently working on, is the use of games. Game based learning, also called 'serious games', has become an academic genre and using games for learning and training has proven fruitful [3-12]. In the military, games have been used for simulation purposes [13] and spin offs from these have also reached a commercial market [14, 15]. Using games in education opens up a range of opportunities. One of them is within the area of Crisis Communication. Crisis Communication as a curriculum is about how to approach the area of crisis communication, understanding the key concepts and develop skills within the curriculum. Games that support communication between the gamers can for instance contribute towards a greater understanding of communication in a crisis situation. What is needed to communicate and how messages are received, in order to support handling a crisis, are amongst the concrete learning objectives one can attribute towards this type of training. To use games to support the hands on training can thus provide the learners with valuable know how, and support their learning outcome. The learning from this will be beneficial to the organizations they work in as they will have an experience that will aid them in the work on planning for and preparing for crisis in their own organizations

Student input-A case of an extended flipped classroom

© 2017 IEEE. The idea from Socrates about the knowledge being a part of the students' knowledge base or ability of combining accessible knowledge forms the backdrop for how the most recent course in Knowledge Management (spring of 2017) was conducted. The course is 7,5 ECTS and the students are primarily adults in a worklife. The course is net and seminar based, with three seminars per semester. During the seminars the concept of Flipped Classroom is used. This means that the students are provided with a recorded lecture in beforehand and only highlights are presented. The rest of the time during the seminar is used to activate the students through tasks and problem solving. However, the tasks are not predefined and prefabricated. The way this course is structured, the students themselves are giving the input to the tasks and assignments. This is based on the idea that the students themselves, coming from a worklife where knowledge management is a part of their every day worklife, should reflect upon their own practice. Also, it is important to share knowledge and by utilizing each students own experiences it is possible to enrich the 'database' of cases or tasks for the students to solve and work with in order to incorporate the new theory from the course curriculum. Basing the problem solving on student input provide the lecturer AND the students with a richer knowledge base and case portfolio. This does, however, require some effort from the lecturers side. The input from the students are generally key words and fragments. The session is facilitated by the lecturer, encouraging the students to bring forward own experiences or situations they would like resolved, either real or fiction. The key words and fragments are discussed amongst the students and the lecturer makes notes on a blackboard or on a digital canvas (MS PowerPoint or similar). The students are given a break and the lecturer collects the key words and synthesizes this into a case. Upon the return of the students, they solve the cases in groups and discuss possible solutions and what theory that apply to the different aspects of the case. Then a plenary session is facilitated where a suggested solution is developed. During a one-day seminar three to four cases are developed as a 'joint venture' amongst the students and the lecturer. The feedback from the students is very positive. They claim that this way of working strongly contributes to an enhanced learning outcome. Some students also report on utilizing knowledge acquired at these seminars back at their workplace. These are some results from the survey and interviews. This research will be presented in detail in the paper. We will also elaborate on how this way of flipping the classroom can be utilized in different courses and areas

A simulational and theoretical study of the spherical electrical double layer for a size-asymmetric electrolyte: the case of big coions

Monte Carlo simulations of a spherical macroion, surrounded by a size-asymmetric electrolyte in the primitive model, were performed. We considered 1:1 and 2:2 salts with a size ratio of 2 (i.e., with coions twice the size of counterions), for several surface charge densities of the macrosphere. The radial distribution functions, electrostatic potential at the Helmholtz surfaces, and integrated charge are reported. We compare these simulational data with original results obtained from the Ornstein-Zernike integral equation, supplemented by the hypernetted chain/hypernetted chain (HNC/HNC) and hypernetted chain/mean spherical approximation (HNC/MSA) closures, and with the corresponding calculations using the modified Gouy-Chapman and unequal-radius modified Gouy-Chapman theories. The HNC/HNC and HNC/MSA integral equations formalisms show good concordance with Monte Carlo "experiments", whereas the notable limitations of point-ion approaches are evidenced. Most importantly, the simulations confirm our previous theoretical predictions of the non-dominance of the counterions in the size-asymmetric spherical electrical double layer [J. Chem. Phys. 123, 034703 (2005)], the appearance of anomalous curvatures at the outer Helmholtz plane and the enhancement of charge reversal and screening at high colloidal surface charge densities due to the ionic size asymmetry.Comment: 11 pages, 7 figure

imported berry mix cake suspected to be the source of infection in Norway

Ongoing hepatitis A outbreak in Europe 2013 to 2014

Systemic sclerosis is associated with specific alterations in gastrointestinal microbiota in two independent cohorts.

ObjectiveTo compare faecal microbial composition in patients with systemic sclerosis (SSc) from 2 independent cohorts with controls and to determine whether certain genera are associated with SSc-gastrointestinal tract (GIT) symptoms.DesignAdult patients with SSc from the University of California, Los Angeles (UCLA) and Oslo University Hospital (OUH) and healthy controls participated in this study (1:1:1). All participants provided stool specimens for 16S rRNA sequencing. Linear discriminant analysis effect size demonstrated genera with differential expression in SSc. Differential expression analysis for sequence count data identified specific genera associated with GIT symptoms as assessed by the GIT 2.0 questionnaire.ResultsThe UCLA-SSc and OUH-SSc cohorts were similar in age (52.1 and 60.5 years, respectively), disease duration (median (IQR): 6.6 (2.5-16.4) and 7.0 (1.0-19.2) years, respectively), gender distribution (88% and 71%, respectively), and GIT symptoms (mean (SD) total GIT 2.0 scores of 0.7 (0.6) and 0.6 (0.5), respectively). Principal coordinate analysis illustrated significant microbial community differences between SSc and controls (UCLA: p=0.001; OUH: p=0.002). Patients with SSc had significantly lower levels of commensal genera deemed to protect against inflammation, such as Bacteroides (UCLA and OUH), Faecalibacterium (UCLA), Clostridium (OUH); and significantly higher levels of pathobiont genera, such as Fusobacterium (UCLA), compared with controls. Increased abundance of Clostridium was associated with less severe GIT symptoms in both cohorts.ConclusionsThe present analysis detected specific aberrations in the lower GIT microbiota of patients with SSc from 2 geographically and ethnically distinct cohorts. These findings suggest that GIT dysbiosis may be a pathological feature of the SSc disease state

Universality in two-dimensional Kardar-Parisi-Zhang growth

We analyze simulations results of a model proposed for etching of a crystalline solid and results of other discrete models in the 2+1-dimensional Kardar-Parisi-Zhang (KPZ) class. In the steady states, the moments W_n of orders n=2,3,4 of the heights distribution are estimated. Results for the etching model, the ballistic deposition (BD) model and the temperature-dependent body-centered restricted solid-on-solid model (BCSOS) suggest the universality of the absolute value of the skewness S = W_3 / (W_2)^(3/2) and of the value of the kurtosis Q = W_4 / (W_2)^2 - 3. The sign of the skewness is the same of the parameter \lambda of the KPZ equation which represents the process in the continuum limit. The best numerical estimates, obtained from the etching model, are |S| = 0.26 +- 0.01 and Q = 0.134 +- 0.015. For this model, the roughness exponent \alpha = 0.383 +- 0.008 is obtained, accounting for a constant correction term (intrinsic width) in the scaling of the squared interface width. This value is slightly below previous estimates of extensive simulations and rules out the proposal of the exact value \alpha=2/5. The conclusion is supported by results for the ballistic deposition model. Independent estimates of the dynamical exponent and of the growth exponent are 1.605 <= z <= 1.64 and \beta = 0.229 +- 0.005, respectively, which are consistent with the relations \alpha + z = 2 and z = \alpha / \beta.Comment: 8 pages, 9 figures, to be published in Phys. Rev.

Abrupt grain boundary melting in ice

The effect of impurities on the grain boundary melting of ice is investigated through an extension of Derjaguin-Landau-Verwey-Overbeek theory, in which we include retarded potential effects in a calculation of the full frequency dependent van der Waals and Coulombic interactions within a grain boundary. At high dopant concentrations the classical solutal effect dominates the melting behavior. However, depending on the amount of impurity and the surface charge density, as temperature decreases, the attractive tail of the dispersion force interaction begins to compete effectively with the repulsive screened Coulomb interaction. This leads to a film-thickness/temperature curve that changes depending on the relative strengths of these interactions and exhibits a decrease in the film thickness with increasing impurity level. More striking is the fact that at very large film thicknesses, the repulsive Coulomb interaction can be effectively screened leading to an abrupt reduction to zero film thickness.Comment: 8 pages, 1 figur