867 research outputs found
Magnetic field generated resistivity maximum in graphite
In zero magnetic field, B, the electrical resistivity, rho(O,T) of highly oriented pyrolytic (polycrystalline) graphite drops smoothly with decreasing T, becoming constant below 4 K. However, in a fixed applied magnetic field B, the resistivity rho(B,T) goes through a maximum as a function of T, with larger maximum for larger B. The temperature of the maximum increases with B, but saturates to a constant value near 25 K (exact T depends on sample) at high B. In single crystal graphite a maximum in rho(B,T) as a function of T is also present, but has the effects of Landau level quantization superimposed. Several possible explanations for the rho(B,T) maximum are proposed, but a complete explanation awaits detailed calculations involving the energy band structure of graphite, and the particular scattering mechanisms involved
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Phase two of the source release modeling for the Los Alamos Area G Disposal Facility Performance Assessment
Analytic and numerical modeling of the aqueous phase release to the unsaturated zone of low level radioactive waste from a shallow burial disposal facility was initiated last year (Phase One) for the Los Alamos Area G Performance Assessment. This year (Phase Two) the effort is continuing to refine the results in the previous analyses. The previous results showed that the {open_quote}rapid release{close_quote} waste category (with solid-liquid phase partition coefficient, K{sub d} = 0) dominates the peak release concentrations and therefore controls the offsite dose. The model for the dissolution transition from the waste package solid phase to liquid phase for the rapid release inventory is improved to reflect a transition limited by the local percolation rate. The analytic solution to the previous model was singular for this case, and so a new solution is derived and applied to the site assessment. A detailed numerical analysis is completed of transient percolation and its effect on the source release model output as a function of time. Transients can be significant locally but attain average values rapidly over local variations in time and space. The site inventory is sorted into groups by time period of interest, allowing analysis of nuclide solubility limits by individual disposal unit. A detailed implementation of the source release model has been incorporated directly into the source term module of the 3-D unsaturated zone computational model used in the site performance assessment
Flipped gaming-testing three simulation games
© 2018 IEEE. At the Inland Norway University of Applied Sciences 'flipped gaming' has been tested with two student groups (in 2017). This paper will present a newer version of the 'flipping' and also how a total of eight groups utilized tree different types of simulators to play the scenarios. The scenarios were developed by the student themselves as this was their mandatory assignment. The mandatory assignment was handed out in January. The assignment was about making a playable script for an incident, in addition to conduct the planning, execution and evaluation of a complete exercise in crisis management. They were given feedback once before the workshop where they presented and played the script. The tools that were used was Rayvn (https://rayvn.global/), Microsoft HoloLens (https://www.microsoft.com/nb-no/hololens) and a simulator based on a platform from Bohemia Interactive Solutions (https://bisimulations.com/)-the same platform as Virtual Battle Space 3 uses. Rayvn is an incident management tool, mainly for communication. The written messages can then be logged and stored for later reflections. Microsoft HoloLens is a tool for 3D vision, a tool that can show environments in 3D and allow the player to carry out operations using movements that are recorded and executed. This was a prototype. The game based simulator is computer based. The different views are 2D maps and 3D environments. The players use the keyboard and mouse to move the vehicles and avatars around. This in a 'disaster town', called 'Lyngvik', a very poor planned city centre with a large accident/crisis potential. The study is based on the previous study of the learning outcome from assignment that is based on student input. The mandatory assignment was to develop a playable scenario and they could choose in which of the three different simulation tools they were to play their scenario. Two by two, the groups are to play each other's scenario. They have received some supervision and the lecturers have remarked on that the students may lack insight in what a 'playable scenario' require. One of the groups operates as the exercise management staff(the ones that makes the incidents happen and 'play out') and the other group is the ones who man the different roles in handling the scenario e.g.,-different call out services. This group is also calledmain training audience (MTA). The students are in their 6th and last semester in their Bachelor in Crisis Management. The students have been subjected to diverse teaching methods, but this is the first time they have a simulation tool to work with in order to enhance their learning outcome. The preliminary reports from the reflections after the simulating are very positive. The students report on a learning outcome, both from making the scenarios and from simulating. There is also a final report to be written where the students are to reflect on their learning outcome from the simulation and the work on the assignment. The paper shows the results from the whole undertaking and presents further details from the different phases. We also present the theoretical backdrop and the methodological reasoning behind the data collection and analysis
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
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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
How does Artificial Intelligence Pose an Existential Risk?
Alan Turing, one of the fathers of computing, warned that Artificial Intelligence (AI) could one day pose an existential risk to humanity. Today, recent advancements in the field AI have been accompanied by a renewed set of existential warnings. But what exactly constitutes an existential risk? And how exactly does AI pose such a threat? In this chapter we aim to answer these questions. In particular, we will critically explore three commonly cited reasons for thinking that AI poses an existential threat to humanity: the control problem, the possibility of global disruption from an AI race dynamic, and the weaponization of AI
The electrical double layer for a fully asymmetric electrolyte around a spherical colloid: an integral equation study
The hypernetted chain/mean spherical approximation (HNC/MSA) integral
equation is obtained and solved numerically for a totally asymmetric primitive
model electrolyte around a spherical macroparticle. The ensuing radial
distribution functions show a very good agreement when compared to our Monte
Carlo and molecular dynamics simulations for spherical geometry and with
respect to previous anisotropic reference HNC calculations in the planar limit.
We report an analysis of the potential vs charge relationship, radial
distribution functions, mean electrostatic potential and cumulative reduced
charge for representative cases of 1:1 and 2:2 salts with a size asymmetry
ratio of 2. Our results are collated with those of the Modified Gouy-Chapman
(MGC) and unequal radius Modified Gouy-Chapman (URMGC) theories and with those
of HNC/MSA in the restricted primitive model (RPM) to assess the importance of
size asymmetry effects. One of the most striking characteristics found is
that,\textit{contrary to the general belief}, away from the point of zero
charge the properties of an asymmetric electrical double layer (EDL) are not
those corresponding to a symmetric electrolyte with the size and charge of the
counterion, i.e. \textit{counterions do not always dominate}. This behavior
suggests the existence of a new phenomenology in the EDL that genuinely belongs
to a more realistic size-asymmetric model where steric correlations are taken
into account consistently. Such novel features can not be described by
traditional mean field theories like MGC, URMGC or even by enhanced formalisms,
like HNC/MSA, if they are based on the RPM.Comment: 29 pages, 13 figure
Preclinical/subclinical rheumatoid arthritis-associated interstitial lung disease: misleading terms with potentially deleterious consequences
Interstitial lung disease (ILD) is a leading cause of mortality in patients with rheumatic diseases, including rheumatoid arthritis. The 5-year mortality rate is twice as high in patients with rheumatoid arthritis-associated ILD than in patients with rheumatoid arthritis without ILD. Moreover, a report showed that mortality rates in patients with disease codes for rheumatoid arthritis-associated ILD remained unchanged from 2005–18, even though the overall rheumatoid arthritis mortality rate declined during this time period. Despite the evidence that ILD contributes to premature death in rheumatoid arthritis, screening for ILD in patients with rheumatoid arthritis is not routinely performed in clinical practice and numerous questions remain regarding the management of rheumatoid arthritis-associated ILD
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