HVEM tomography: A new tool for the cell biologist

1993 ◽  
Vol 51 ◽  
pp. 548-549
Author(s):  
Joachim Frank
Keyword(s):  
Rapid Development ◽  
Three Dimensional ◽  
Full Potential ◽  
Automated Data Collection ◽  
3D Images ◽  
The Past ◽  
Cell Biologist ◽  
Transmission Electron ◽  
On Line ◽  
Transmission Microscope

The technique of three-dimensional imaging with the transmission electron microscope is a new tool ready to be used by the cell biologist. By itself, the transmission microscope is not capable of producing 3D images, but it allows collection of a tilt series of projections in a wide angular range. From such a series, a 3D image can be reconstructed using established mathematical principles. The first reconstructions of this kind were obtained by Walter Hoppe’s group in 1974, but the full potential of this approach was not realized until the mid-80’s when computers with sufficient speed and memory became available.Especially within the past three years, there has been a rapid development in the areas of instrumentation, computation, and visualization. New tilt stages meet the demands of high accuracy and wide angular coverage. Direct image readout systems and on-line control of the microscope make it possible to design automated data collection systems.

Nanostructure in Traditional Composites of Natural Rubber and Reinforcing Silica

2007 ◽  
Vol 80 (4) ◽  
pp. 690-700 ◽  
Author(s):  
Atsushi Kato ◽  
Shinzo Kohjiya ◽  
Yuko Ikeda
Keyword(s):  
Electron Microscopy ◽  
Carbon Black ◽  
Natural Rubber ◽  
Electron Tomography ◽  
3D Visualization ◽  
Three Dimensional ◽  
Rubber Matrix ◽  
3D Images ◽  
Transmission Electron ◽  
Filler Dispersion

Abstract Usual rubber products are a composite from rubber and nano-filler (e.g. silica, carbon black, etc.), and it is believed that the good dispersion of the nano-filler is the most important issue determining the performance of rubber vulcanizates. So far, transmission electron microscopy (TEM) has been the most useful tool for evaluation of the dispersion. However, it affords images of the sample projected on an x, y-plane, and the information along the thickness (z-axis) direction is missing. Three-dimensional (3D) visualization of nanometer structure of nano-filler dispersion in a rubber matrix is what all rubber technologists have been dreaming of. This dream is at last realized, and described in this paper. Use of TEM combined with computerized tomography (abbreviated as 3D-TEM in this paper, which is sometimes called electron tomography) enabled us to reconstruct 3D images of nano-filler (silica or carbon black) aggregates in rubbery matrix. It is said that nano-filler aggregate is a structure of size from 10 nm to 1000 nm, and agglomerate is an even larger structure. The 3D-TEM results on silica aggregates in natural rubber were presented in this paper. Silica aggregates were characterized by combining the 3D images of the vulcanizates. Furthermore, density of silica loaded natural rubber as an example of physical properties, was measured, and explained by the structure elucidated by 3D-TEM.

scholarly journals An Analysis of 3D Steganography Techniques

Electronics ◽  
2021 ◽  
Vol 10 (19) ◽  
pp. 2357
Author(s):  
Rohit Tanwar ◽  
Urmila Pilania ◽  
Mazdak Zamani ◽  
Azizah Abdul Manaf
Keyword(s):  
Image Processing ◽  
Systematic Study ◽  
Research Work ◽  
Three Dimensional ◽  
3D Images ◽  
The Past ◽  
Work Done ◽  
Evaluation Parameters

Steganography has become a preferred technique these days to successfully hide secret messages. Various research has been done in the past to justify and analyze suitable types of cover file, such as images, audio, videos, etc. Advancement in the image-processing domain has opened various possibilities of using three-dimensional (3D) images as cover files. In this paper, a systematic study of the research work done on 3D steganography in the last fifteen years has been carried out. The study is divided into different sections based on the types of algorithms used, additional security features, evaluation parameters, etc. Moreover, certain steganalysis techniques that are applicable for 3D steganography are also discussed.

Three-Dimensional Morphology of Carbon Black in NR Vulcanizates as Revealed by 3D-Tem and Dielectric Measurements

2006 ◽  
Vol 79 (4) ◽  
pp. 653-673 ◽  
Author(s):  
Atsushi Kato ◽  
Junichi Shimanuki ◽  
Shinzo Kohjiya ◽  
Yuko Ikeda
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Physical Properties ◽  
Rational Design ◽  
Electron Tomography ◽  
3D Visualization ◽  
Three Dimensional ◽  
Rubber Matrix ◽  
3D Images ◽  
Transmission Electron

Abstract Usual rubber products are a composite from rubber and nano-filler (e.g. carbon black, silica, etc.), and it is believed that the good dispersion of the nano-filler is the most important issue determining the performance of rubber vulcanizates. So far, transmission electron microscopy (TEM) has been the most useful tool for evaluation of the dispersion. However, it affords images of the sample projected on an x, y-plane, and the information along the thickness (z-axis) direction is missing. Three-dimensional (3D) visualization of nanometer structure of nano-filler dispersion in a rubber matrix is what all rubber technologists have been dreaming of. This dream is at last realized, and described in this paper. Use of TEM combined with computerized tomography (abbreviated as 3D-TEM in this paper, which is sometimes called electron tomography) enabled us to reconstruct 3D images of nano-filler aggregates in rubbery matrix. The 3D-TEM results on carbon black in natural rubber were presented in this paper. The network structure formed by agglomeration of carbon black aggregates was elucidated by combining the 3D images and physical properties of the vulcanizates. Density, electrical resistivity and dielectric relaxation of carbon black loaded natural rubber as an example of physical properties, were measured, and explained by the structure elucidated by 3D-TEM. This technique will prove to be more and more important for the rational design of the nano-composites of rubbery matrix.

scholarly journals Metabolic engineering of Vibrio natriegens

2021 ◽  
Author(s):  
Felix Thoma ◽  
Bastian Blombach
Keyword(s):  
Metabolic Engineering ◽  
Marine Bacterium ◽  
Genomic Organization ◽  
Current Knowledge ◽  
Rapid Development ◽  
High Growth ◽  
Full Potential ◽  
The Past ◽  
Consumption Rates ◽  
Production Host

Abstract Vibrio natriegens is emerging as a promising host for biotechnology which is basically due to the remarkable intrinsic properties such as the exceptionally high growth and substrate consumption rates. The facultatively anaerobic marine bacterium possesses a versatile metabolism, is able to utilize a variety of substrates as carbon and energy sources and is easy to handle in the lab. These features initiated the rapid development of genetic tools and resulted in extensive engineering of production strains in the past years. Although recent examples illustrate the potential of V. natriegens for biotechnology, a comprehensive understanding of the metabolism and its regulation is still lacking but essential to exploit the full potential of this bacterium. In this review, we summarize the current knowledge on the physiological traits and the genomic organization, provide an overview of the available genetic engineering tools and recent advances in metabolic engineering of V. natriegens. Finally, we discuss the obstacles which have to be overcome in order to establish V. natriegens as industrial production host.

scholarly journals Effects of Construction Sequences and Volume Loss on Perpendicularly Crossing Tunnels

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Yanwei Zang ◽  
Penglu Gan ◽  
Jia-jia Yan ◽  
Shiming Liu ◽  
Zihai Yan
Keyword(s):  
Urban Areas ◽  
Rapid Development ◽  
Three Dimensional ◽  
Ground Surface ◽  
Stress Transfer ◽  
Bending Moment ◽  
Small Strain ◽  
Research Attention ◽  
The Past ◽  
Three Dimensional Finite Element

The number of constructed tunnels has been gradually increasing for the past decades due to rapid development in urban areas. However, the soil-structure interaction problems arising from perpendicularly crossing tunnels attract relatively little research attention in the past. In this study, six three-dimensional finite element analyses were conducted to simulate tunnel excavation nearby a perpendicularly crossing existing tunnel, in an attempt to investigate the effects of construction sequences on cross-cutting tunnels. The hypoplastic constitutive model for sand is adopted in the numerical analysis to consider the soil small-strain stiffness. Computed results are presented and discussed in terms of ground surface settlement, displacement and deformation of the existing tunnel, and bending moment induced on the existing tunnel. The stress-transfer mechanism in soil nearby the existing tunnel due to tunnelling is also studied.

scholarly journals Digitalization of Bulgarian Cultural Heritage

2019 ◽  
Vol 8 (1) ◽  
pp. 6
Author(s):  
Georgi Nikolov Georgiev
Keyword(s):  
Cultural Heritage ◽  
Visual Information ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Digital Technologies ◽  
3D Images ◽  
The Past ◽  
Virtual Reconstruction ◽  
Ict Tools ◽  
Historical Heritage

The research of historical heritage is related to creation, storage and distribution of visual information about them. With the development of digital technologies, the three-dimensional scanning and visual regeneration of buildings of cultural heritage combined with 3D virtual reconstruction is becoming increasingly important tool for understanding and reconstructing the past. Instead of expensive laser scanning, cheaper photogrammetric methods for creating and processing of spatial (3D) images of historical and architectural monuments are finding a growing application. The article analyses the opportunities for use of different ICT tools, including inexpensive digital imaging options for preservation and exhibiting of large and diverse Bulgarian cultural heritage.

A multimedia case-based reasoning framework for assembly sequence planning

2019 ◽  
Vol 39 (4) ◽  
pp. 673-684
Author(s):  
Junhao Chen ◽  
Xiaoliang Jia
Keyword(s):  
Process Design ◽  
Design Methodology ◽  
Rapid Development ◽  
Three Dimensional ◽  
Assembly Sequence Planning ◽  
Case Based Reasoning ◽  
Assembly Sequence ◽  
Content Type ◽  
Sequence Planning ◽  
The Past

Purpose Assembly sequence planning (ASP) is a crucial job during assembly process design. However, it is still difficult to reuse the existing solution to solve a new ASP problem. In particular, with the rapid development of digital technologies, the reusable assembly information of an existing solution is not concentrated in one multimedia but dispersed in multiple heterogeneous multimedia, e.g. text, three-dimensional graphics, even images and videos. This paper aims to propose a multimedia case (MC)-based reasoning framework to solve ASP by reusing the existing solution whose assembly information is dispersed in multimedia. Design/methodology/approach The proposed framework is designed with the introduction of the MC. An MC seamlessly integrates the dispersed assembly information of an existing solution. Under the proposed concept and architecture, the assembly information of an existing solution is extracted to build assembly descriptors of multimedia. Therefore, the MC is captured by organizing the assembly descriptors of corresponding multimedia. Findings By means of the framework proposed, it is possible to reuse the existing solution whose assembly information is dispersed in multimedia to solve ASP. Moreover, the extraction method of assembly information can flexibly parse most of the multimedia. Finally, the MC has the capability to represent the existing solution by collecting dispersed assembly information. Originality/value The proposed framework can discover the similar existing solution and avoid the potential failures confronted in the past so that the feasibility of ASP result can be improved as much as possible.

scholarly journals 2D/3D Halide Perovskites for Optoelectronic Devices

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiang Chen ◽  
Hai Zhou ◽  
Hao Wang
Keyword(s):  
Performance Enhancement ◽  
Rapid Development ◽  
Three Dimensional ◽  
Light Emitting ◽  
The Past ◽  
Carbon Chains ◽  
Aliphatic Carbon ◽  
Halide Perovskites ◽  
Future Direction ◽  
Perovskite Lattice

The traditional three-dimensional (3D) halide perovskites (HPs) have experienced rapid development due to their highly power conversion efficiency (PCE). However, the instability of 3D perovskite on humidity and UV irradiation blocks their commercialization. In the past few years, two-dimensional (2D) halide perovskites attract much attention because they behave better stability due to the water resistance of the aliphatic carbon chains in the 2D perovskite lattice. In this review, we categorize the 2D/3D perovskites based on the applications [i.e., solar cells (SCs), light-emitting diodes (LEDs) and photodetectors (PDs)]. We further discuss the recent efforts in the performance enhancement of the 2D/3D perovskite-based devices. However, there are still some difficulties before 2D/3D HPs is fully commercialized. We will provide some scientific and technical challenges and prospects in the article to point out the future direction.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

Sign in / Sign up

Export Citation Format

Share Document