scholarly journals 3D IMAGING OF INDIVIDUAL PARTICLES: A REVIEW

2012 ◽  
Vol 31 (2) ◽  
pp. 65 ◽  
Author(s):  
Eric Pirard

In recent years, impressive progress has been made in digital imaging and in particular in three dimensional visualisation and analysis of objects. This paper reviews the most recent literature on three dimensional imaging with a special attention to particulate systems analysis. After an introduction recalling some important concepts in spatial sampling and digital imaging, the paper reviews a series of techniques with a clear distinction between the surfometric and volumetric principles. The literature review is as broad as possible covering materials science as well as biology while keeping an eye on emerging technologies in optics and physics. The paper should be of interest to any scientist trying to picture particles in 3D with the best possible resolution for accurate size and shape estimation. Though techniques are adequate for nanoscopic and microscopic particles, no special size limit has been considered while compiling the review.

MRS Bulletin ◽  
2003 ◽  
Vol 28 (4) ◽  
pp. 284-289 ◽  
Author(s):  
E. Maire ◽  
A. Elmoutaouakkil ◽  
A. Fazekas ◽  
L. Salvo

AbstractThe use of microtomography to study the structure and especially the deformation modes of cellular solids is reviewed in this article. First, the technique is described in detail. Examples illustrating the power of the coupling ofin situdeformation with three-dimensional (3D) imaging, drawn from the recent literature and the authors' own work, are then given. The most detailed example is the study of the deformation modes of several samples made of different aluminum foams. Four kinds of closed-cell foams were investigated, corresponding to different routes available today for their manufacture. The initial macrostructure was quantified using the 3D images combined with 3D granulometry, allowing retrieval of pertinent information about the cell size and the wall and strut thicknesses. The global behavior exhibited by the foams during thein situcompression experiments was shown to vary from one brand of material to another. Some of these variations can be explained by differences in the known microstructure and the measured macrostructure of the samples.


2014 ◽  
Vol 08 (01) ◽  
pp. 132-140 ◽  
Author(s):  
Orhan Hakki Karatas ◽  
Ebubekir Toy

ABSTRACTImaging is one of the most important tools for orthodontists to evaluate and record size and form of craniofacial structures. Orthodontists routinely use 2-dimensional (2D) static imaging techniques, but deepness of structures cannot be obtained and localized with 2D imaging. Three-dimensional (3D) imaging has been developed in the early of 1990’s and has gained a precious place in dentistry, especially in orthodontics. The aims of this literature review are to summarize the current state of the 3D imaging techniques and to evaluate the applications in orthodontics.


Author(s):  
Tibor A. Zwimpfer ◽  
Claudine Wismer ◽  
Bernhard Fellmann-Fischer ◽  
James Geiger ◽  
Andreas Schötzau ◽  
...  

AbstractLaparoscopic surgery provides well-known benefits, but it has technological limitations. Depth perception is particularly crucial, with three-dimensional (3D) imaging being superior to two-dimensional (2D) HD imaging. However, with the introduction of 4K resolution monitors, 2D rendering is capable of providing higher-quality visuals. Therefore, this study aimed to compare 3D HD and 2D 4K imaging using a pelvitrainer model. Eight experts and 32 medical students were performing the same four standardized tasks using 2D 4K and 3D HD imaging systems. Task completion time and the number of errors made were recorded. The Wilcoxon test and mixed-effects models were used to analyze the results. Students were significantly faster in all four tasks when using the 3D HD perspective. The median difference ranged from 18 s in task 3 (P < 0.003) up to 177.5 s in task 4 (P < 0.001). With the exception of task 4, students demonstrated significantly fewer errors in all tasks involving 3D HD imaging. The experts’ results confirmed these findings, as they were also faster in all four tasks using 3D HD, which was significant for task 1 (P < 0.001) and task 4 (P < 0.006). The expert group also achieved better movement accuracy using the 3D HD system, with fewer mistakes made in all four tasks, which was significant in task 4 (P < 0.001). Participants in both groups achieved better results with the 3D HD imaging system than with the 2D 4K system. The 3D HD image system should be used when available. Trial registration: this trial is registered at research registry under the identifier researchregistry6852.


2015 ◽  
Vol 5 (2) ◽  
pp. 80-85 ◽  

ABSTRACT Objectives Different types of X-ray equipment are used in dental radiology. Purpose of this study was to measure the absorbed doses of some critical organs and tissues in head and neck which were exposed by dental imaging devices that are used routinely in dental radiology. Materials and Methods Radiation exposures were performed by using a human equivalent head phantom and dose measurements were determined with thermoluminescent dosimeters (TLD). After exposure of the phantom with dental imaging devices, absorbed and effective doses of critical organs were determined. Results Digital imaging systems produced lower effective doses. Effective doses of cone beam computed tomography (CBCT) and multi-slice computed tomography (MSCT) devices were close to each other. Conclusion Effective doses of digital imaging devices were measured lower than conventional imaging devices. Effective doses of 3D imaging devices were measured higher than all the other imaging devices. However, effective doses of 3D imaging devices were considered in acceptable levels. How to cite this article Eren H, Gorgun S. Evaluation of Effective Dose with Two-dimensional and Three-dimensional Dental Imaging Devices. J Contemp Dent 2015;5(2):80-85.


Author(s):  
Neil Rowlands ◽  
Jeff Price ◽  
Michael Kersker ◽  
Seichi Suzuki ◽  
Steve Young ◽  
...  

Three-dimensional (3D) microstructure visualization on the electron microscope requires that the sample be tilted to different positions to collect a series of projections. This tilting should be performed rapidly for on-line stereo viewing and precisely for off-line tomographic reconstruction. Usually a projection series is collected using mechanical stage tilt alone. The stereo pairs must be viewed off-line and the 60 to 120 tomographic projections must be aligned with fiduciary markers or digital correlation methods. The delay in viewing stereo pairs and the alignment problems in tomographic reconstruction could be eliminated or improved by tilting the beam if such tilt could be accomplished without image translation.A microscope capable of beam tilt with simultaneous image shift to eliminate tilt-induced translation has been investigated for 3D imaging of thick (1 μm) biologic specimens. By tilting the beam above and through the specimen and bringing it back below the specimen, a brightfield image with a projection angle corresponding to the beam tilt angle can be recorded (Fig. 1a).


Author(s):  
Judith M. Brock ◽  
Max T. Otten

A knowledge of the distribution of chemical elements in a specimen is often highly useful. In materials science specimens features such as grain boundaries and precipitates generally force a certain order on mental distribution, so that a single profile away from the boundary or precipitate gives a full description of all relevant data. No such simplicity can be assumed in life science specimens, where elements can occur various combinations and in different concentrations in tissue. In the latter case a two-dimensional elemental-distribution image is required to describe the material adequately. X-ray mapping provides such of the distribution of elements.The big disadvantage of x-ray mapping hitherto has been one requirement: the transmission electron microscope must have the scanning function. In cases where the STEM functionality – to record scanning images using a variety of STEM detectors – is not used, but only x-ray mapping is intended, a significant investment must still be made in the scanning system: electronics that drive the beam, detectors for generating the scanning images, and monitors for displaying and recording the images.


Author(s):  
Halit Dogan ◽  
Md Mahbub Alam ◽  
Navid Asadizanjani ◽  
Sina Shahbazmohamadi ◽  
Domenic Forte ◽  
...  

Abstract X-ray tomography is a promising technique that can provide micron level, internal structure, and three dimensional (3D) information of an integrated circuit (IC) component without the need for serial sectioning or decapsulation. This is especially useful for counterfeit IC detection as demonstrated by recent work. Although the components remain physically intact during tomography, the effect of radiation on the electrical functionality is not yet fully investigated. In this paper we analyze the impact of X-ray tomography on the reliability of ICs with different fabrication technologies. We perform a 3D imaging using an advanced X-ray machine on Intel flash memories, Macronix flash memories, Xilinx Spartan 3 and Spartan 6 FPGAs. Electrical functionalities are then tested in a systematic procedure after each round of tomography to estimate the impact of X-ray on Flash erase time, read margin, and program operation, and the frequencies of ring oscillators in the FPGAs. A major finding is that erase times for flash memories of older technology are significantly degraded when exposed to tomography, eventually resulting in failure. However, the flash and Xilinx FPGAs of newer technologies seem less sensitive to tomography, as only minor degradations are observed. Further, we did not identify permanent failures for any chips in the time needed to perform tomography for counterfeit detection (approximately 2 hours).


2021 ◽  
Vol 13 (2) ◽  
pp. 563
Author(s):  
Bing Ran ◽  
Scott Weller

Despite the growing utility and prevalence of social entrepreneurship, an accepted definition remains elusive and infeasible. Yet, it is imperative that the principles guiding social entrepreneurship are identified so that common ground is established to facilitate future research. On the basis of a systematic literature review, this conceptual paper proposes a theoretical framework outlining social entrepreneurship as a three-dimensional framework as a function of continua of “social” and “business” logics, “beneficial” and “detrimental” social change logics, and “innovation” and “mundane” logics. The framework accommodates the fuzziness and ambiguity associated with social entrepreneurship whilst remaining a workable, identifiable construct. By accounting for the shifting logics practiced by social entrepreneurship that both influence and are influenced by the organizational environment, this framework provides an exit strategy for the definitional elusiveness of social entrepreneurship. The resultant structures and functions of social entrepreneurship are shaped by these constraints as reflected by the fluidity and flexibility endorsed by the framework. Four avenues for future research regarding social entrepreneurship are recommended on the basis of the framework proposed in this article.


Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3652
Author(s):  
Cory Juntunen ◽  
Isabel M. Woller ◽  
Yongjin Sung

Hyperspectral three-dimensional (3D) imaging can provide both 3D structural and functional information of a specimen. The imaging throughput is typically very low due to the requirement of scanning mechanisms for different depths and wavelengths. Here we demonstrate hyperspectral 3D imaging using Snapshot projection optical tomography (SPOT) and Fourier-transform spectroscopy (FTS). SPOT allows us to instantaneously acquire the projection images corresponding to different viewing angles, while FTS allows us to perform hyperspectral imaging at high spectral resolution. Using fluorescent beads and sunflower pollens, we demonstrate the imaging performance of the developed system.


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