Modelling shape of architectural structure: Elliptic hyperboloid of one sheet

The combination of straight lines of constructive elements and curved contours of structural shapes is always challenging in the engineering practice. The 2nd order surface - elliptic hyperboloid of one sheet (ELHY) provides such combination. Given that in the architectural surroundings, arts, or other scientific fields ELHY is less common, than the other representatives of the same family of ruled surfaces, it is worth of attention and research. Here presented constructive geometry approach resulted in Auto CAD application for generating 3D wire-frame and triangulated net model of ELHY surface and some examples of structures - prototypes of structural shapes, designed by using ELHY fragments. [Projekat Ministarstva nauke Republike Srbije, br. TR36008: Development and application of scientific methods in design and building of high economic structural systems by application of new technologies, the part of which is the present study

On the role of circular sections of quadric surfaces

As a part of new advanced course curriculum of Descriptive geometry, in the Faculty of Civil engineering, creative 3D modeling of specific structures is included. These structures, inspired by contemporary architecture achievements, relay on quadric surfaces (quadrics). Here, student's knowledge concerning properties of the quadrics: cone, sphere, ellipsoid, elliptic hyperboloid, etc. (also elaborated in the course - Mathematics 2, in the same year of the studies) is necessary. Throughout two given 3D modeling tasks, students elaborate two separate subtopics: discretization of the surface elliptic hyperboloid of one sheet (ELHY) and spiral surfaces, both connected by key elements circular sections of quadrics. The subtopic's presentation methodology designed for students is conducted by "steps" in 3D structures modeling process, aided by applications and tools of most common engineering software Auto CAD. The applications presented below are created on a base of analytical geometry methods. The first topic - discretization of ELHY surface, i.e. generation of polygonal mesh structure, has a rather simple explanation and graphical presentation (wireframe and surface models) of geometrical procedures, i.e. constructions in opposite to the available analytical geometry solutions. A method of generating the ELHY surface is based on two arbitrary circular sections and one generatrix. The accompanying CAD application, created in Auto lisp, as a tool for discretization has the purpose to enable creative 3D task solution - model of geometric structure ELHY shaped. Three different options/solutions of discretization are offered. The second topic regarding 3D models of spiral surfaces/structures is nowadays very popular in the architecture. Here included spiral surfaces are one which geometric origins are quadrics. Since the term "spiral" is directly connected to the rotation and circle, geometric concept relay again on the circular sections of quadrics. This topic is supported by a Visual basic application (VBA) procedure implemented in Auto CAD. It also requires advanced 3D modeling tools for the design and visualization process of the final product. If comparing two given tasks, the second one is more creative and optional, while the students role in designing is more significant. However, we are sure that both tasks have an important educational value in better understanding of theory regarding quadric surfaces. It is reasonable to expect that in a certain moment (according to the level of programming knowledge) student could create his own software solution, or modify the offered one (application), aimed for such geometric topics. According to the palette of the surfaces included, variety of final "products" - structures and their purposes should be resulted in buildings, furniture, or art design

Comparing tablets (touchscreen devices) and PCs in preschool children' education: testing spatial relationship using geometric symbols on traffic signs

Touchscreen devices have dramatically increased the accessibility and usage of technology, causing escalating usage, especially by very young children. Although the effects of screen time have been shown to produce serious (negatively effects on executive functioning, attention problems, school difficulties, sleep and eating disorders, and obesity) and even life-threatening consequences (due to radiation emission), technology can be beneficial if it is carefully used. Child-centered technology is especially designed to be as entertaining and captivating as possible. In order to examine how touchscreen devices, influence the acquisition of some important spatial concepts and provide exciting opportunities for learning new abilities, an experimental research was conducted aimed to determine whether the type of device used (computers or tablets) in the natural kindergarten environment influences young children performances. For the purpose of this work, geometrical symbols on traffic signs were used to test spatial relationships – left/right, and longer/shorter relations. The test was carried out on a sample of 30 pre-school children. The results show significant differences between the two-testing media for identifying the longer vs. shorter relationships in favor of Tablet PC. Based on the results obtained, it can be concluded that the kinesthetic characteristics of tablets, the novelty factor and the opportunity to learn through playing, provide a positive approach to the early childhood education. Besides, the interactive environment created in a kindergarten by using tablets contributes to introduce new teaching methods which are expected to amplify the pedagogical capacity, changing the way of spatial concepts acquisition, as well as, children traffic education take place within

Perception of three-dimensional geometric shapes as virtual 3D road markings

Excessive speed and poor driver perception are the causes of a large number of traffic accident. Analysis of the influence of geometry in driver behavior has been widely performed by different researchers. One way to improve road safety is to provide adequate visibility in order to help drivers adopt adequate behaviors. When budget and financial situation do not allow the implementation of expensive traffic solutions, some of them can be replaced by innovative, but simple solutions. In this study, the experiment was performed to explore how driver perception and behavior are influenced by two virtual 3D shapes projections - 3D alternative crosswalk pattern and speed bumps consisted from triangular prisms. The results show statistically significant differences between willingness to reduce vehicle speed as a response to the road marking using the square (rectangular prism) as the basis compared to one that has been used triangle (triangular prism)

Synthesis and characterization of a new diiminedioxime ligand and its copper (ii) complex as potential 64Cu(ii)-radiopharmaceuticals

As a part of effort to an develop 64Cu-based radiopharmaceuticals for PET (positron emission tomography) imaging of multidrug resistance in cancer, a new diiminedioxime ligand was prepared. Its Cu(II) complex was synthesized from Cu(OAc)2 by heating in methanol. The structure of the ligand was established using elemental analysis, UV-Vis, IR, 1H and 13C NMR technique. The isolated complex was characterized by means of elemental analysis, IR and UV-Vis, and its structure was proposed

Application of ascorbic acid as a radiolytic stabilizer for [131I]mibg

In this paper the results of a stability of [131I]mIBG, stored under various conditions, are presented. The stability was followed during 14 days. The most important radiochemical impurity in [131I]mIBG is free [131I]iodide, formed by radiolysis. The results indicate that the rate of radiolytic decomposition of [131I]mIBG is much slower at higher concentration of ascorbic acid (20 mg/mCi) and at lower storage temperature (40C)

Climate, host and geography shape insect and fungal communities of trees.

Non-native pests, climate change, and their interactions are likely to alter relationships between trees and tree-associated organisms with consequences for forest health. To understand and predict such changes, factors structuring tree-associated communities need to be determined. Here, we analysed the data consisting of records of insects and fungi collected from dormant twigs from 155 tree species at 51 botanical gardens or arboreta in 32 countries. Generalized dissimilarity models revealed similar relative importance of studied climatic, host-related and geographic factors on differences in tree-associated communities. Mean annual temperature, phylogenetic distance between hosts and geographic distance between locations were the major drivers of dissimilarities. The increasing importance of high temperatures on differences in studied communities indicate that climate change could affect tree-associated organisms directly and indirectly through host range shifts. Insect and fungal communities were more similar between closely related vs. distant hosts suggesting that host range shifts may facilitate the emergence of new pests. Moreover, dissimilarities among tree-associated communities increased with geographic distance indicating that human-mediated transport may serve as a pathway of the introductions of new pests. The results of this study highlight the need to limit the establishment of tree pests and increase the resilience of forest ecosystems to changes in climate

Climate, host and geography shape insect and fungal communities of trees

13 Pág.Non-native pests, climate change, and their interactions are likely to alter relationships between trees and tree-associated organisms with consequences for forest health. To understand and predict such changes, factors structuring tree-associated communities need to be determined. Here, we analysed the data consisting of records of insects and fungi collected from dormant twigs from 155 tree species at 51 botanical gardens or arboreta in 32 countries. Generalized dissimilarity models revealed similar relative importance of studied climatic, host-related and geographic factors on differences in tree-associated communities. Mean annual temperature, phylogenetic distance between hosts and geographic distance between locations were the major drivers of dissimilarities. The increasing importance of high temperatures on differences in studied communities indicate that climate change could affect tree-associated organisms directly and indirectly through host range shifts. Insect and fungal communities were more similar between closely related vs. distant hosts suggesting that host range shifts may facilitate the emergence of new pests. Moreover, dissimilarities among tree-associated communities increased with geographic distance indicating that human-mediated transport may serve as a pathway of the introductions of new pests. The results of this study highlight the need to limit the establishment of tree pests and increase the resilience of forest ecosystems to changes in climate.We gratefully acknowledge the financial support of the Swiss National Science Foundation (Project C15.0081) Grant 174644 and the Swiss Federal Office for the Environment Grant 00.0418.PZ/P193-1077. This work was supported by COST Action “Global Warning” (FP1401). CABI is an international intergovernmental organisation, and R.E., M.K., H.L. and I.F. gratefully acknowledge the core financial support from our member countries (and lead agencies) including the United Kingdom (Foreign, Commonwealth and Development Office), China (Chinese Ministry of Agriculture and Rural Affairs), Australia (Australian Centre for International Agricultural Research), Canada (Agriculture and Agri-Food Canada), Netherlands (Directorate General for International Cooperation), and Switzerland (Swiss Agency for Development and Cooperation). See https://www.cabi.org/aboutcabi/who-we-work-with/key-donors/ for full details. M.B. and M.K.H. were financially supported by the Slovak Research and Development Agency (Project APVV-19-0116). H.B. would like to thank the botanist Jorge Capelo who helped with Myrtaceae identification and INIAV IP for supporting her contribution to this study. Contributions of M. de G. and B.P. were financed through Slovenian Research Agency (P4-0107) and by the Slovenian Ministry of Agriculture, Forestry and Food (Public Forestry Service). G.C, C.B.E. and A.F.M. were supported by OTKA 128008 research grant provided by the National Research, Development and Innovation Office. Contributions of K.A. and R.D. were supported by the Estonian Research Council grants PSG136 and PRG1615. M.J.J., C.L.M. and H.P.R. were financially supported by the 15. Juni Fonden (Grant 2017-N-123). P.B., B.G. and M.Ka. were financially supported by the Ministry of Science and Higher Education of the Republic of Poland for the University of Agriculture in Krakow (SUB/040013-D019). C.N. was financially supported by the Slovak Research and Development Agency (Grant APVV-15-0531). N.K. was partially supported by the Russian Science Foundation (grant № 22-16-00075) [species identification] and the basic project of Sukachev Institute of Forest SB RAS (№ FWES-2021-0011) [data analysis]. R.OH. was supported by funding from DAERA, and assistance from David Craig, AFBI. T.P. thanks the South African Department of Forestry, Fisheries and the Environment (DFFE) for funding noting that this publication does not necessarily represent the views or opinions of DFFE or its employees. In preparing the publication, materials of the bioresource scientific collection of the CSBG SB RAS “Collections of living plants indoors and outdoors” USU_440534 (Novosibirsk, Russia) were used. M.Z. was financially supported by Ministry of Science, Technological Development and Innovation of the Republic of Serbia (contract no. 451-03-47/2023-01/200197). We acknowledge the Genetic Diversity Centre (GDC) at ETH Zurich for providing computational infrastructure and acknowledge the contribution of McGill University and Génome Québec Innovation Center (Montréal, Quebec, Canada) for pair-end sequencing on Illumina MiSeq. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe

Comparing Tablets (touchscreen devices) and PCs in Preschool Education: Testing Spatial Relationship Using Geometric Symbols of Traffic Signs

Touchscreen devices have dramatically increased the accessibility and usage of technology, causing escalating usage, especially by very young children. Although the effects of screen time have been shown to produce serious (negatively effects on executive functioning, attention problems, school difficulties, sleep and eating disorders, and obesity) and even life-threatening consequences (due to radiation emission), technology can be beneficial if it is carefully used. Child-centered technology is especially designed to be as entertaining and captivating as possible. In order to examine how touchscreen devices, influence the acquisition of some important spatial concepts and provide exciting opportunities for learning new abilities, an experimental research was conducted aimed to determine whether the type of device used (computers or tablets) in the natural kindergarten environment influences young children performances. For the purpose of this work, geometrical symbols on traffic signs were used to test spatial relationships – left/right, and longer/shorter relations. The test was carried out on a sample of 30 pre-school children. The results show significant differences between the two-testing media for identifying the longer vs. shorter relationships in favor of Tablet PC. Based on the results obtained, it can be concluded that the kinesthetic characteristics of tablets, the novelty factor and the opportunity to learn through playing, provide a positive approach to the early childhood education. Besides, the interactive environment created in a kindergarten by using tablets contributes to introduce new teaching methods which are expected to amplify the pedagogical capacity, changing the way of spatial concepts acquisition, as well as, children traffic education take place within

The use of new technological devices in testing and education of young children

Rastući trend korišćenja uređaja povezanih na internet, posebno ekrana na dodir, tablet računara iliPC računara, podstiče napore da se unapredi metodologija edukacije i testiranja dece na ovom polju. Da bi se istražila ova nastojanja analiziran je tradicionalni i savremeni pristup testiranja dece uzrasta od 6 do 9 godina. Tradicionalni pristup uključuje testiranje na papiru, dok savremeni podrazumeva rešavanje istog problema na tablet računaru ili PC računaru. Za potrebe eksperimenta korišćen je neverbalni test koji se odnosi na prepoznavanje 2D i 3D geometrijskih oblika. Testiranje je sprovedeno na uzorku od 180 dece iz urbanih i ruralnih sredina. Rezultati prikazuju uzrastne i polne razlike, kao i razlike u postignuću na testovima između dece iz urbane i ruralne sredine. Cilj rada je da se ispitaju potencijalne razlike koje nastaju usled različitih pristupa testiranja i edukacije dece (tradicionalnog i savremenog). Na osnovu istraživanja, može se zaključiti da deca ispoljavaju veću motivaciju i postižu bolje rezultate u rešavanju zadataka kada koriste tablet računar iliPC računara. U skladu sa rezultatima rada, primena novih tehnologija u edukaciji dece može doprineti efikasnijem savladavanju sadržaja različitih kurseva, nego što je to slučaj kod klasičnog pristupa