86 research outputs found
REMOTE: An overview of the FLUKA particle transport code and its graphical user interface Flair
No full textAbstract:An overview shall be presented of FLUKA, a general-purpose code for the Monte Carlo simulation of radiation transport, and of its powerful graphical interface Flair. FLUKA can transport over 60 particle species, including photons, leptons, hadrons and ions, at energies up to the PeV domain and down to the keV domain, with the exception of neutrons, which can be transported down to the meV. Material geometries can be described via FLUKA's combinatorial geometry package, from the simplest geometries up to elaborate geometries e.g. extended portions of the Large Hadron Collider. FLUKA accounts for the most relevant electromagnetic and hadronic interaction mechanisms, providing a self-contained approach to the simulation of coupled hadronic and electromagnetic radiation showers. FLUKA's graphical user interface Flair provides a fully integrated environment to run FLUKA, from the preparation of the input file, to the construction of the geometry, specification of the radiation source, of the quantities to be scored. Furthermore, it controls the execution of the simulation, the processing of output files, and the visualization of simulation results. To showcase the capabilities of Flair and FLUKA, several application examples shall be presented, ranging from neutronics to medical physics. Short Bio Vasilis VlachoudisDr. Vasilis Vlachoudis has a PhD in Nuclear Physics from Univ. of Bordeaux France. Currently holds a senior staff position as physicist in the Beam Matter Interactions section at CERN. The section is in charge of the FLUKA MC code development and its application to the CERN accelerator complex. Vasilis is leading the FLUKA (https://fluka.cern) code development and he is the lead author of flair (https://flair.cern) graphical interface used for FLUKA and for other MC codes. Furthermore, Vasilis has an active role in the neutron time of flight facility at CERN as responsible for the spallation target physics optimisation and design, as well as the experimental data processing chain.</p
The Psárský forest in the district of Prague - West as a location of school science excursion
No full textDiplomová práce NÁZEV: Psárský les v okrese Praha - západ jako lokalita přírodovědné školní exkurze AUTOR: Bc. Michala Prokopcová KATEDRA: Katedra biologie a environmentálních studií, Pedagogická fakulta, Univerzita Karlova VEDOUCÍ PRÁCE: doc. RNDr. Vasilis Teodoridis, Ph.D. ABSTRAKT Tato diplomová práce zpracovává lokalitu Psárského lesa v okrese Praha - západ jako vhodnou oblast pro realizaci přírodovědné školní exkurze. Hlavním cílem této práce byla příprava a realizace komplexní přírodovědné exkurze do Psárského lesa a ověření její edukační efektivity u žáků nižších tříd 2. stupně ZŠ formou pedagogického výzkumu. Výzkum byl uskutečněn prostřednictvím didaktických testů, které porovnávaly vstupní znalosti před exkurzí (pretest) a nabyté znalosti po exkurzi (posttest). Didaktický koncept přírodovědné exkurze do Psárského lesa byl zpracován v souladu s klíčovými aspekty oborové didaktiky biologie a na základě komplexního vyhodnocení zájmové oblasti pro plánovanou exkurzi, která tvořila podklad pro exkurzní náplň a vytipování vhodných stanovišť k exkurzním činnostem. Dále v rámci diplomové práce proběhlo navazující šetření prostřednictvím postojového dotazníku ke zjištění přínosu exkurzí ve výuce přírodopisu z pohledu žáků. Výsledky výzkumu potvrzují, že exkurze je vnímána jako efektivní a zároveň...Thesis TITLE: The Psárský forest in the district of Prague - West as a location of school science excursion AUTHOR: Bc. Michala Prokopcová DEPARTMENT: Department of Biology and Environmental Studies, Faculty of Education, Charles University SUPERVISOR: doc. RNDr. Vasilis Teodoridis, Ph.D. ABSTRACT The aim of the thesis is to examine the Psárský forest locality in the Prague-West region as regards its suitability for a school science excursion. The principal objective of the thesis was to prepare and take a comprehensive science excursion to Psárský forest and verify its educational efficiency for pupils of lower secondary school grades by means of pedagogical research. The research was carried out through didactical tests comparing the initial knowledge before the excursion (pretest) and acquired knowledge after the excursion (posttest). The didactical concept of the science excursion to Psárský forest was elaborated in accordance with the key aspects of the field biology didactics and based on complex evaluation of the fields of interest for the excursion planned to become a basis for the excursion contents and selection of suitable places for excursion activities. In addition to this, subsequent research via the attitude questionnaire to identify the excursions benefits within natural science education from...Katedra biologie a environmentálních studiíPedagogická fakultaFaculty of Educatio
Content analyses of the textbooks of biology (natural history) for pupils with hearing impairment as a starting point for creating workbooks
No full textTITLE: Content analyses of the textbooks of biology (natural history) for pupils with hearing impairment as a starting point for creating workbooks AUTHOR: RNDr. Jana Skýbová DEPARTMENT: Biology and Environmental Studies, Faculty of Education, Charles University in Prague TUTOR: doc. RNDr. Vasilis Teodoridis, Ph.D. ABSTRACT: The main aim of the dissertation thesis was to perform content analyses textbooks of biology (natural history) for elementary schools dedicated for pupils with hearing impairment as a base for the special workbooks creation in accordance with curricular and legislative documents. The next aim of thesis was the realization of educational research in all elementary schools for pupils with hearing impairment in the Czech Republic that focusing on teaching process of natural sciences and work with existing (author's) special textbooks for these pupils with accent on analysis of requirements of teachers and pupils for newly created workbooks. Methods of the mentioned pedagogic research was qualitative and quantitative, i.e. questionnaire complemented by interviews. The results of empirical research using textbooks of biology (natural history) in elementary schools dedicated for pupils with hearing impairment in the Czech Republic derived from the current requirements of the teacher-..
Students’ experiences and views on co-teaching: a systematic review
No full textFollowing the international inclusion movement, co-teaching between special and general educators has appeared as one approach to the education of students with and without disabilities in the general education classroom (Strogilos et al., 2017). Co-teaching consists of general and special educators partnering to plan, deliver, and assess instruction in a general education class where, together, they teach students with and without disabilities (Friend et al., 2010). Research on co-teaching has extensively grown in the last decades, due to the increasing number of schools which are educating students with disabilities in co-taught classrooms.Research on co-teaching has focused on its process and impact and especially the use of co-teaching models by the two educators. Seminal studies on co-teaching noted that during co-teaching both educators should be responsible for ‘instructional planning and delivery, assessment of student achievement, and classroom management’ (Nevin at al., 2008, p. 284), and highlighted that educators’ collaboration is paramount in responding to students’ needs (Thousand et al., 2006). Cook and Friend (1995) proposed a number of co-teaching models that co-teachers can select to group their students and to deliver instruction: one teacher leading while the other assists or observes (one-teach, one-assist/ observe/ circulate); both educators share the planning and delivering of instruction by each leading instruction (team teaching), the two teachers dividing students in half (parallel or alternative teaching); and dividing students in stations (station teaching). Systematic reviews on co-teaching:The last 20 years a number of reviews have been published mainly to describe teachers’ views on co-teaching (Iacono et al., 2021; Paulsrud & Nilholm, 2020; Scruggs et al., 2007; Solis et al., 2012; Strogilos et al., 2023; Van Garderen et al., 2012) or their students’ academic outcomes (King-Sears et al., 2021; Stefanidis et al., 2023). Only one review describes students’ perception on co-teaching (Wagner et al., 2023), which focuses on the identification of contextual variables surrounding co-teaching and some of its benefits and challenges. In some countries (e.g., England; DfE, 2015), the law requires the involvement of students with disabilities in decisions pertaining their education to empower a historically silenced group. Although the concept of ‘student voice’ has received increased attention, their participation in research studies depends on adult researchers’ perspectives on students’ ability to exercise influence upon their social world (Christensen & Prout, 2005). Students with and without disabilities who are educated in co-taught classes can provide valuable feedback about these experiences, which can be useful for not only researchers but for co-teachers and other school personnel striving to set up effective co-taught classes (e.g., Embury & Kroeger, 2012). Indeed, as more researchers establish lines of research that include students with and without disabilities in their studies (e.g., Leafstedt et al., 2007; Ronn-Lijenfeldt et al., 2023), students are important contributors about what does and does not promote their learning when co-taught. A systematic review on students’ views on co-teaching to synthesise all the different themes that have appeared in research studies is currently missing. The main aim of the present systematic review is to describe students’ views about a plethora of features that contribute towards students’ academic and social success in co-taught classrooms and to highlight valuable implications for policy, practice and research to improve co-teaching. The review is guided by the following research questions: What are the views of students with and without disabilities about co-teaching? What improvements can be made on co-teaching based on students’ feedback? Methods To identify studies, we undertook computerised searches in EBSCO, ERIC, Academic Search Complete, PsycINFO, OmniFile Full Text Select (H.W. Wilson), Open Dissertations, ProQuest Dissertations and Conference Proceedings Citation Index-Science. The search dates were between June 2023 and January 1990. We used the search terms: “coteach*”; “co-teaching”; “cooperative teaching”; “co-operative teaching”; “team teaching”; and “collaborative teaching” with the boolean operator “or” between the terms to search related titles, abstracts and keywords. “Calls to the field” for unpublished studies via social media and emails to organisations (e.g., AERA). References in eligible articles were hand-searched. Two authors independently examined titles, abstracts, and full texts. The inter-rater reliability for determining eligible studies was 87%. Another author scrutinised discrepancies to 100% consensus.Eligible criteria included: (a) original published or unpublished studies with primary data from students with and/or without disabilities in co-taught classrooms; (b) K-12 grades; (c) students received instruction from general and special educators as co-teachers; (d) in English; (e) when other participants in the study (e.g., parents, teachers), data from the students were disaggregated. Exclusion criteria included: (a) research with student data that was about inclusion but not about co-teaching; (b) data from others (e.g., co-teachers) was aggregated with the student data such that disaggregation could not occur; (c) students were preservice teachers rather than in K-12 grades; (d) general and special educators as part of a larger team working together but not co-teaching; (e) research featuring student’s academic achievement (e.g., standardized tests) only; (f) research in which co-teaching appeared in the findings but was not in the research aims/questions; and (g) studies which featured students responding to social validity surveys, with queries about aspects of a newly implemented intervention. For studies which featured other participants (e.g., co-teachers), only the portion featuring students was included. There were 15,203 records identified from the search; 8,758 were excluded due to repetition. The 6,445 records remaining were screened by title and abstract. After excluding non-related articles, full-text search occurred for 179 studies, with 68 considered eligible.Each study was reviewed for quality using either the Critical Appraisal Skills Program tool/checklist (CASP, 2018) for qualitative studies, or the checklist to assess quality of survey studies (Protogerou & Hagger, 2020). Findings included descriptive statistics and correlations from surveys, and themes from interviews and other qualitative methods. We employed thematic analysis (Braun et al., 2019) to elicit themes from the primary studies and to produce a narrative synthesis.Conclusions, expected outcomes or findings Our preliminary analysis elicited eight main themes about students’ views on co-teaching: Models of co-teaching, prevalence, and student preferences; the roles of co-teachers and their collaboration; student feelings; academic learning; social participation; behaviour management; belonging; and self-efficacy. Students with and without disabilities believe that co-teaching has an overall positive academic and social impact on all students. Many students with and without disabilities reported important academic benefits from both teachers. When the co-taught class was not the place they were learning best, this was attributed to teachers’ insufficient collaboration, lack of individual support for students with disabilities, or the lack of academic challenges for students without disabilities. Students with and without disabilities also reported positive views on their social participation in the co-taught classrooms, especially in relation to friendships. Other important findings include the prevalence of the “one teach, one assist/drift/observe” model and students’ preference for a variety of co-teaching models; students’ satisfaction that special educators can support all students and not just students with disabilities; and students’ view that when there is a low level of co-teachers’ collaboration occurring, this creates frustration and leads to low academic benefits. In addition, most students expressed positive feelings about having two teachers, noting that co-teaching can be fun. However, some students with disabilities were confused and frustrated when the material was difficult or when co-teachers were speaking simultaneously. Also, some felt stigmatised when the special educator was constantly working near their desk. The few studies that examined students’ belonging and self-efficacy reported high levels for both attributes and, in some cases, positive associations between them and student academic progress. Based on the above, we intent to discuss the following: improvements on co-teaching, factors related to findings, cautions about future research, and implications for policy and practice. <br/
Material tests report - Wrapped Composite Joints project
No full textInterest in composites for application in Civil Engineering structures, has seen significant increase in recent years. From composite repairs on existing structures from concrete or structural steel, to composite decks in bridges or even structures made solely out of fibre reinforced composites, the structural industry is following the already existing trend in automotive and aerospace industry where composite solutions present a great potential that traces back to 1960’s. Within this framework the Wrapped Composite Joints project, under Dr. M. Pavlovic, attempts to bring the composites technology to jacket designs of offshore wind turbines and replace the traditional welding technology that is used for connecting the steel tubular members of the jacket frame. Higher stiffness, more sustainable and lightweight design due to reduced steel weight and most importantly higher fatigue resistance are just some of the benefits that the developing technology brings in the structure. Developing a new technology especially when a novel material solution is used, requires robust knowledge of the inherent material as well as bond properties. For this experimental testing series should take place along different structural levels. Goal of such experimental series is to investigate the capabilities of the material as well as the assembled components up to total failure.In the current Additional graduation work a coupon testing series comprising of different standard test methods, part of the Wrapped Composite joints project is presented. Aim of this study is the establishment of fundamental material elastic as well as fracture properties for the composite layup used in the project. Outcomes of the experimental study will be used as input for the realistic representation of the material and the bonded interface through Finite Element Models(FEM) of several scales, from small specimens to large and full scale Joints.Civil Engineerin
Towards a Low Emission Port: Development of a decision making tool for technologies for the reduction of the shore-related emission footprint of existing ports in respect to the stakeholders’ values
No full textEnergy-related and environmental issues are getting more attention and are becoming more important over the years. Currently, they are considered as one of the greatest challenges worldwide. The widespread use of fossil fuels causes the increase of the harmful emissions which are associated with significant health and environmental issues. Ports are no exception to this problem as they are considered as major contributors. Although there are some measures available, the high majority of them focus only on technologies that can reduce the vessel emissions. The focus of this research study is on the development of a decision making tool for technologies that can be used for the reduction of the emission footprint of the ports’ shore-operations. The decision making for such technologies is not an easy process. The large number of stakeholders, the environmental concerns as well as the fast changing business environment create a complicated decision making scheme. This scheme represents specific practical and theoretical issues which need to be addressed. A list of known theories that solve these issues and a list of methods and tools that deal with values and data were used for the development. The developed decision making tool describes a ten step approach that provides specific guidelines and sub-tools for the assessment of the port’s situation and the technologies until the final technology selection. Considering the diverse character of ports, their fast changing business environment as well as the innovations concerning the low emission technologies, this tool has no static data-input. It reacts with the business environment and provides with the best technology choice related to the values of the stakeholders at a specific moment of time. The developed tool was applied as an illustration study to the port of Piraeus for the following vision: ““Implementation of renewable energy technologies for electricity generation that can reduce the emission footprint of the Piraeus’ shore-operations”. The decision making tool can be used by port authorities either as the main decision tool or as supplementary tool that provides port authorities with an indication. The tool can be applied to all types of ports without restrictions such as the size or the economic activity. Its main characteristic is that it quantifies the decision making process by creating a “common language” for understanding the current situation in terms of decision criteria importance and technology opportunities. The application of the tool proved that it is particularly efficient for gradually identifying the values and their importance as decision criteria. The idea of dynamic input of data provides the flexibility to possible changes which consists an important aspect for making responsible decisions. Electrical Engineering | Sustainable Energy Technolog
Development and Preliminary Evaluation of the Main Features of the Particle Finite Element Method (PFEM) for Solid Mechanics
No full textThe Particle Finite Element Method is a numerical tool that has been introduced more than a decade ago for the solution of engineering problems involving large deformations. The method falls under the category of mesh-based particle methods, meaning that all information is stored on moving particles that represent the domain under analysis and a computational mesh is used for the solution of the governing equations. Although the method was initially developed for simulating fluid\hyp{}structure interaction problems, owing to its versatility in handling large deformation and constant changes in domain boundaries and contact interfaces, it has been recently employed for solid mechanics applications. However, the lack of a consistent framework for this kind of problems has lead to different implementations of the method presented in the literature, each with its own special features. The main objective of this thesis is to implement a variation of the Particle Finite Element Method and investigate the efficiency of the different features available in literature. Initially, the meshing procedure of the method was developed, which consists of a Delaunay triangulation for assessing the connectivity of the particles and the -shape method for detection of the boundaries of the different domains. This was followed by an investigation on the influence of the related parameter on the outcome of the analysis; it appears that this choice has an impact on the results, in terms of the recovered domain volumes and the simulation response; this parameter has to be selected with care, with respect to the nature of the examined problem. Volume variations are also observed, caused by element deletion and/or addition during remeshing, which, eventually, lead to mass oscillations. These effects can be mitigated by either adjusting the value of the parameter, refining the particle distribution or prescribing the boundary surface during remeshing, by using a constrained Delaunay triangulation.Another important feature of the PFEM is the treatment of contact, which is, typically, done in literature via employment of an interface mesh. This mesh is generated during remeshing, using the same scheme as for the regular domain meshes, i.e. a Delaunay triangulation and the -shape method, and the generated contact elements are then used to enforce the contact constraints, with a variety of methods. In this work, a simple algorithm that disallows inter-penetration and allows free separation and free movement perpendicular to the contact surfaces was formulated and validated against benchmark solid mechanics problems. The automatic contact detection and interface mesh generation allows for the incorporation of more advanced contact treatment schemes.Transference of information between successive meshes is important in PFEM for solid mechanics, especially when the history of elemental variables, e.g. stresses, is required for capturing the solid material behavior accurately. The most popular technique is the nodal smoothing technique, where the values are mapped back and forth between the integration points and the particles at each time step; other schemes have been also presented in literature. This scheme has been shown to introduce some smoothing of information, which can be reduced by refining the particle distribution and, in general, does not seem to affect the overall system response significantly. The developed method was, finally, compared with the available in-house implicit Material Point Method code, which shares the same formulation, on some benchmark quasi-static and dynamic solid mechanics problems. The PFEM demonstrates a more stable behavior in terms of capturing the evolution of stresses and kinematic variables, despite some inaccuracies caused by the smoothing of information and the use of simple, constant-strain triangles. On the other hand, the MPM -in its standard form- exhibits some instabilities in the assembly of equations and stress recovery, which is intensified when cell-crossing occurs, i.e. jumping of material points between elements. Regarding the computational cost of the two methods, the MPM seems to be faster and require less computer memory for the same number of information points, i.e. particles, with the simulation times, however, increasing exponentially with the number of degrees of freedom
Numerical investigation of passive heat transfer enhancement in mixed convective turbulent flows
No full textHeat transfer deterioration has been observed by researchers in turbulent upward flows under the effect of buoyancy. This is a problem for industrial applications since deteriorated heat transfer requires heat exchangers of increased volume and cost. Passive heat transfer enhancement in turbulent mixed convection upward flows through a uniformly heated pipe is studied numerically, using RANS modelling. A constant properties approach is implemented, using the Boussinesq approximation to predict the influence of buoyancy. Turbulence is modelled using two different models, the “Menter shear stress transport turbulence model” and “Spalart-Allmaras” model. Numerical simulations of air flows are conducted at a turbulent Reynolds number of 𝑅𝑒=5300, at a uniform pipe wall heating rate of 𝑞𝑤𝑎𝑙𝑙=1285 𝑊/𝑚2. The effect of transverse rib geometries on heat transfer is studied for various pitch-to-diameter, 𝑝/𝐷, and depth-to-diameter, 𝑒/𝐷, ratios, with ranges equal to 𝑝/𝐷= 1−1.75 and 𝑒/𝐷 = 0.1 −0.175. The effect of ribs on heat transfer is compared to the effect on flow friction, using the overall enhancement ratio, 𝜂. Results show that transverse rib geometries can lead to a maximum overall enhancement of 𝜂=2.20 and 𝜂=2.30 depending on the turbulence model. Recommendations for further research are presented in the end.Mechanical Engineering | Energy, Flow and Process Technolog
Mixed Integer Linear Programming (MILP) Approach to Deal with Spatio-temporal Water Allocation
No full textAbstractWater of sufficient quantity and quality is indispensable for multiple purposes like domestic use, irrigated agriculture, hydropower generation and ecosystem functioning. However, in many regions of the world water availability is limited and even declining. Moreover, water availability is variable in space and time so that it does not match with the spatio-temporal use pattern of the water consumers. To overcome the temporal discrepancy between availability and consumption, reservoirs are constructed. Monitoring and predicting the water available in the reservoirs, the needs of the consumers and the losses throughout the water distribution system are necessary requirements to fairly allocate the available water for the different consumers. In this article, the water allocation problem is considered as a Network Flow Optimization Problem (NFOP) to be solved by a spatio-temporal optimization approach using Mixed Integer Linear Programming (MILP) techniques
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