Molecular manufacturing: perspectives on the ultimate limits of fabrication

1995 ◽  
Vol 353 (1703) ◽  
pp. 323-331 ◽  
Keyword(s):  
Molecular Machine ◽  
Atomic Precision ◽  
Scale Structures ◽  
Characteristic Features ◽  
Manufacturing Productivity ◽  
Machine Systems ◽  
Molecular Manufacturing ◽  
Defect Densities

Molecular machine systems, common in biology, can become a basis for a new style of physical technology. Characteristic features of the proposed systems and their products include nanometre-scale structures, atomic precision, low defect densities, and high manufacturing productivity.

Ferrocene-containing non-interlocked molecular machines

2016 ◽  
Vol 52 (12) ◽  
pp. 2451-2464 ◽  
Author(s):  
Synøve Ø. Scottwell ◽  
James D. Crowley
Keyword(s):  
Ball Bearing ◽  
Molecular Machines ◽  
Redox Properties ◽  
Molecular Machine ◽  
Molecular Systems ◽  
Reversible Redox ◽  
Wide Range ◽  
Machine Systems

Ferrocene is chemically robust and readily functionalized which enables its facile incorporation into more complex molecular systems. This coupled with ferrocene's reversible redox properties and ability to function as a “molecular ball bearing” has led to the use of ferrocene as a component in wide range of non-interlocked synthetic molecular machine systems.

scholarly journals Toward the Regulation of Molecular Machine Systems by Terahertz Waves

2013 ◽  
Vol 49 (11) ◽  
pp. 1082-1084
Author(s):  
Miki HIRABAYASHI ◽  
Ibuki KAWAMATA ◽  
Masami HAGIYA ◽  
Hiroaki KOJIMA ◽  
Kazuhiro OIWA
Keyword(s):  
Molecular Machine ◽  
Terahertz Waves ◽  
Machine Systems

Characteristics of perovskite-related materials

1989 ◽  
Vol 328 (1599) ◽  
pp. 409-416 ◽  
Keyword(s):  
Phase Transitions ◽  
Perovskite Structure ◽  
Structural Phase ◽  
Structural Instability ◽  
Structural Phase Transitions ◽  
Kinetic Behaviour ◽  
Characteristic Features ◽  
Polaronic Transport ◽  
Structural Instabilities ◽  
Defect Densities

Oxides with perovskite structure show characteristic features of their physical behaviour that can be relevant for the understanding of the mantle m aterial (MgFe)SiO 3 . Perovskites distort locally, and four different mechanisms have been found: tilt of octahedral complexes, off-centring of the octahedrally coordinated cation, distortion of the octahedral cage and off-centring of the 12-fold coordinated site. These deformations usually lead to structural instabilities related to phase transitions, extremely sluggish kinetic behaviour even leading to pseudo-glasses and polaronic transport. All these properties depend sensitively on the oxygen fugacities, defect densities and the rheology of the system. There is some evidence that the predicted structural phase transitions and glass states occur in CaSiO 3 whereas no structural instability has yet been reported in MgSiO 3 .

Some comments about observations and image processing of comet 29P/Schwassmann-Wachmann 1

1999 ◽  
Vol 173 ◽  
pp. 243-248
Author(s):  
D. Kubáček ◽  
A. Galád ◽  
A. Pravda
Keyword(s):  
Image Processing ◽  
Large Scale ◽  
Harvard College ◽  
Oak Ridge ◽  
Large Scale Structures ◽  
Short Period Comet ◽  
Short Period ◽  
Scale Structures ◽  
Harvard College Observatory ◽  
Period Comet

AbstractUnusual short-period comet 29P/Schwassmann-Wachmann 1 inspired many observers to explain its unpredictable outbursts. In this paper large scale structures and features from the inner part of the coma in time periods around outbursts are studied. CCD images were taken at Whipple Observatory, Mt. Hopkins, in 1989 and at Astronomical Observatory, Modra, from 1995 to 1998. Photographic plates of the comet were taken at Harvard College Observatory, Oak Ridge, from 1974 to 1982. The latter were digitized at first to apply the same techniques of image processing for optimizing the visibility of features in the coma during outbursts. Outbursts and coma structures show various shapes.

Exploring Coronal Structures with SOHO

2000 ◽  
Vol 179 ◽  
pp. 403-406
Author(s):  
M. Karovska ◽  
B. Wood ◽  
J. Chen ◽  
J. Cook ◽  
R. Howard
Keyword(s):  
Solar Corona ◽  
Image Enhancement ◽  
Coronal Mass Ejections ◽  
Dynamical Evolution ◽  
Small Scale ◽  
Low Contrast ◽  
Contrast Structures ◽  
Scale Structures ◽  
Small Scale Structures ◽  
Coronal Structures

AbstractWe applied advanced image enhancement techniques to explore in detail the characteristics of the small-scale structures and/or the low contrast structures in several Coronal Mass Ejections (CMEs) observed by SOHO. We highlight here the results from our studies of the morphology and dynamical evolution of CME structures in the solar corona using two instruments on board SOHO: LASCO and EIT.

Ultrastructural modification of cellular interactions in cancer tumor

1978 ◽  
Vol 36 (2) ◽  
pp. 318-319
Author(s):  
N. P. Dmitrieva
Keyword(s):  
Cancer Cells ◽  
Human Thyroid ◽  
Adjacent Cell ◽  
Main Role ◽  
Cellular Interactions ◽  
Electron Microscopic ◽  
Cancer Tumor ◽  
Normal Human ◽  
Characteristic Features

One of the most characteristic features of cancer cells is their ability to metastasia. It is suggested that the modifications of the structure and properties of cancer cells surfaces play the main role in this process. The present work was aimed at finding out what ultrastructural features apear in tumor in vivo which removal of individual cancer cells from the cell population can provide. For this purpose the cellular interactions in the normal human thyroid and cancer tumor of this gland electron microscopic were studied. The tissues were fixed in osmium tetroxide and were embedded in Araldite-Epon.In normal human thyroid the most common type of intercellular contacts was represented by simple junction formed by the parallelalignment of adjacent cell membranees leaving in between an intermembranes space 15-20 nm filled with electronlucid material (Fig. 1a). Sometimes in the basal part of cells dilatations of the intercellular space 40-50 nm wide were found (Fig. 1a). Here the cell surfaces may form single short microvilli.

Development of 200kV ultrahigh-resolution analytical electron microscope

1989 ◽  
Vol 47 ◽  
pp. 108-109
Author(s):  
T. Kaneyama ◽  
M. Naruse ◽  
Y. Ishida ◽  
M. Kersker
Keyword(s):  
Electron Microscope ◽  
Optical Constants ◽  
Materials Science ◽  
Objective Lens ◽  
The Finite Element Method ◽  
Ultrahigh Resolution ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Characteristic Features ◽  
Better Than

In the field of materials science, the importance of the ultrahigh resolution analytical electron microscope (UHRAEM) is increasing. A new UHRAEM which provides a resolution of better than 0.2 nm and allows analysis of a few nm areas has been developed. [Fig. 1 shows the external view] The followings are some characteristic features of the UHRAEM.Objective lens (OL)Two types of OL polepieces (URP for ±10' specimen tilt and ARP for ±30' tilt) have been developed. The optical constants shown in the table on the next page are figures calculated by the finite element method. However, Cs was experimentally confirmed by two methods (namely, Beam Tilt method and Krivanek method) as 0.45 ∼ 0.50 mm for URP and as 0.9 ∼ 1.0 mm for ARP, respectively. Fig. 2 shows an optical diffractogram obtained from a micrograph of amorphous carbon with URP under the Scherzer defocus condition. It demonstrates a resolution of 0.19 nm and a Cs smaller than 0.5 mm.

Defect reduction in oxygen implanted silicon-on-insulator material during high-temperature annealing

1989 ◽  
Vol 47 ◽  
pp. 604-605
Author(s):  
P. Roitman ◽  
B. Cordts ◽  
S. Visitserngtrakul ◽  
S.J. Krause
Keyword(s):  
High Temperature ◽  
Annealing Temperature ◽  
Silicon On Insulator ◽  
High Dose ◽  
High Temperature Annealing ◽  
High Current ◽  
Defect Reduction ◽  
Annealing Step ◽  
Multiple Cycle ◽  
Defect Densities

Synthesis of a thin, buried dielectric layer to form a silicon-on-insulator (SOI) material by high dose oxygen implantation (SIMOX – Separation by IMplanted Oxygen) is becoming an important technology due to the advent of high current (200 mA) oxygen implanters. Recently, reductions in defect densities from 109 cm−2 down to 107 cm−2 or less have been reported. They were achieved with a final high temperature annealing step (1300°C – 1400°C) in conjunction with: a) high temperature implantation or; b) channeling implantation or; c) multiple cycle implantation. However, the processes and conditions for reduction and elimination of precipitates and defects during high temperature annealing are not well understood. In this work we have studied the effect of annealing temperature on defect and precipitate reduction for SIMOX samples which were processed first with high temperature, high current implantation followed by high temperature annealing.

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