scholarly journals Understanding of Symmetry: Measuring the Contribution of Virtual and Concrete Models for Students with Different Spatial Abilities

2021 ◽  
Vol 68 (3) ◽  
pp. 736-743
Author(s):  
Thayban Thayban ◽  
Habiddin Habiddin ◽  
Yudhi Utomo ◽  
Muarifin Muarifin
Keyword(s):  
Spatial Ability ◽  
Three Dimensional ◽  
Dimensional Representation ◽  
Chemistry Teaching ◽  
Three Dimensional Representation ◽  
Chemical Concepts ◽  
Collection Data ◽  
Quasi Experimental ◽  
Symmetry Tests ◽  
Concrete Model

Virtual and concrete models have been of interest in chemistry teaching to improve students’ understanding of a three-dimensional representation of chemical concepts such as symmetry. This study aims to determine the effectiveness of using concrete and virtual models on students’ understanding of symmetry. Students’ understanding was also explored in light of their spatial ability. The study was conducted using a quasi-experimental design with 62 students as participants. Two different instruments, spatial ability and understanding of symmetry tests, were employed for data collection. Data analysis was performed using the Pearson product-moment correlation and two-way variance analysis test. The results showed the virtual model’s contribution to improving students’ understanding of symmetry is higher than that of the concrete model for both students with high spatial ability (HSA) and low spatial ability (LSA). Also, the better students’ spatial ability, the better their understanding of molecular symmetry.

Revealing gross three-dimensional structure in the SEM

1987 ◽  
Vol 45 ◽  
pp. 656-657
Author(s):  
Sterling P. Newberry
Keyword(s):  
Freeze Drying ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Small Object ◽  
Final Solution ◽  
Dimensional Representation ◽  
X Ray ◽  
Three Dimensional Representation ◽  
Freeze Dried ◽  
Critical Point Drying

The beautiful three dimensional representation of small object surfaces by the SEM leads one to search for ways to open up the sample and look inside. Could this be the answer to a better microscopy for gross biological 3-D structure? We know from X-Ray microscope images that Freeze Drying and Critical Point Drying give promise of adequately preserving gross structure. Can we slice such preparations open for SEM inspection? In general these preparations crush more readily than they slice. Russell and Dagihlian got around the problem by “deembedding” a section before imaging. This some what defeats the advantages of direct dry preparation, thus we are reluctant to accept it as the final solution to our problem. Alternatively, consider fig 1 wherein a freeze dried onion root has a window cut in its surface by a micromanipulator during observation in the SEM.

scholarly journals Structured-light 3D scanning of exhibited historical clothing—a first-ever methodical trial and its results

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Jerzy Montusiewicz ◽  
Marek Miłosz ◽  
Jacek Kęsik ◽  
Kamil Żyła
Keyword(s):  
Cultural Heritage ◽  
Information Technologies ◽  
Structured Light ◽  
Three Dimensional ◽  
3D Models ◽  
3D Scanning ◽  
Dimensional Representation ◽  
3D Scanner ◽  
Three Dimensional Representation ◽  
3D Scanners

AbstractHistorical costumes are part of cultural heritage. Unlike architectural monuments, they are very fragile, which exacerbates the problems of their protection and popularisation. A big help in this can be the digitisation of their appearance, preferably using modern techniques of three-dimensional representation (3D). The article presents the results of the search for examples and methodologies of implementing 3D scanning of exhibited historical clothes as well as the attendant problems. From a review of scientific literature it turns out that so far practically no one in the world has made any methodical attempts at scanning historical clothes using structured-light 3D scanners (SLS) and developing an appropriate methodology. The vast majority of methods for creating 3D models of clothes used photogrammetry and 3D modelling software. Therefore, an innovative approach was proposed to the problem of creating 3D models of exhibited historical clothes through their digitalisation by means of a 3D scanner using structural light technology. A proposal for the methodology of this process and concrete examples of its implementation and results are presented. The problems related to the scanning of 3D historical clothes are also described, as well as a proposal how to solve them or minimise their impact. The implementation of the methodology is presented on the example of scanning elements of the Emir of Bukhara's costume (Uzbekistan) from the end of the nineteenth century, consisting of the gown, turban and shoes. Moreover, the way of using 3D models and information technologies to popularise cultural heritage in the space of digital resources is also discussed.

A Method for Measuring Deformation Rates in Hydrogel Structures: Multi-Plane Imaging and Measurement Limitations

2000 ◽  
Author(s):  
Joseph M. Bauer ◽  
David J. Beebe
Keyword(s):  
Cross Sections ◽  
Particle Image ◽  
Three Dimensional ◽  
Local Deformation ◽  
Dimensional Representation ◽  
Volume Changes ◽  
Mechanical Constraints ◽  
Seed Particles ◽  
Three Dimensional Representation ◽  
Image Velocimetry

Abstract A technique for determining the three dimensional motions of hydrogel structures in microchannels is introduced. In developing this technique, we have adapted microscopic particle image velocimetry (μPIV), a method for measuring velocity fields in microfluidic devices. The motions of 1 μm fluorescent seed particles that are incorporated into a hydrogel microstructure (200 μm tall × 400 μm diameter) are tracked over several expansion cycles using microscopy. Combining measurements taken in different planes produces a three-dimensional representation of the motions present during volume changes can be reconstructed. By providing cross sections of the local deformation rates in hydrogel microstructures, this technique allows for the optimization of device designs as well as providing a better understanding of the processes by which hydrogels change volume under mechanical constraints.

A CAD/CAM Representation Model Applied to Tolerance Transfer Methods

1998 ◽  
Author(s):  
Alain Desrochers
Keyword(s):  
Three Dimensional ◽  
Dimensional Representation ◽  
One Dimensional ◽  
Dimensional Tolerance ◽  
Representation Model ◽  
Three Dimensional Representation ◽  
Tolerance Chart ◽  
Cad Cam ◽  
Tolerance Charts

Abstract This paper presents the adaptation of tolerance transfer techniques to a model called TTRS for Technologically and Topologically Related Surfaces. According to this model, any three-dimensional part can be represented as a succession of surface associations forming a tree. Additional tolerancing information can be associated to each TTRS represented as a node on the tree. This information includes dimensional tolerances as well as tolerance chart values. Rules are then established to simulate tolerance chains or stack up along with tolerance charts directly from the graph. This way it becomes possible to combine traditional one dimensional tolerance transfer techniques with a powerful three-dimensional representation model providing high technological contents.

Has a fully three-dimensional space map never evolved in any species? A comparative imperative for studies of spatial cognition

2013 ◽  
Vol 36 (5) ◽  
pp. 557-557 ◽  
Author(s):  
Cynthia F. Moss
Keyword(s):  
Spatial Cognition ◽  
Dimensional Space ◽  
Large Body ◽  
Three Dimensional ◽  
Comparative Data ◽  
Dimensional Representation ◽  
Three Dimensional Representation ◽  
Space Coding ◽  
Three Dimensional Space

AbstractI propose that it is premature to assert that a fully three-dimensional map has never evolved in any species, as data are lacking to show that space coding in all animals is the same. Instead, I hypothesize that three-dimensional representation is tied to an animal's mode of locomotion through space. Testing this hypothesis requires a large body of comparative data.

scholarly journals A system for generating virtual seeds

1998 ◽  
Vol 55 (spe) ◽  
pp. 39-45 ◽  
Author(s):  
Y. Sako ◽  
K. Fujimura ◽  
M.B. McDonald ◽  
D. James
Keyword(s):  
Three Dimensional ◽  
Promising Method ◽  
Two Dimensional ◽  
Dimensional Representation ◽  
Accurate Identification ◽  
Computer Screen ◽  
Three Dimensional Objects ◽  
Three Dimensional Representation ◽  
Quicktime Vr

Seed analysts need to identify seeds, and seed catalogs are used as a reference to accomplish this task. Conventional seed catalogs supply two-dimensional photographs and hand-drawn diagrams. In this study, a new, three-dimensional representation of seeds is developed to supplement these traditional photographs and drawings. QuickTime VR is a promising method for viewing three-dimensional objects on a computer screen. It permits manipulation of an object by rotating and viewing it from any pre-specified angle at an interactive speed, allowing the viewer the sense of examining a hand-held object. In this study, QuickTime VR object movies of seeds were created as interactive "movies" of seeds that can be rotated and scaled to give the viewer the sensation of examining actual seeds. This approach allows the examination of virtual seeds from any angle, permitting more accurate identification of seeds by seed analysts.

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