scholarly journals New Methods for Studying the Orientation Order of Uniaxial Molecular Films on the Base of Optical Data

2020 ◽  
Vol 20 (1) ◽  
pp. 41-46
Author(s):  
E. M. Aver'yanov
2020 ◽  
Author(s):  
Menachem Domb

Optical Communication (OC) for data transmission was introduced more than 30 years ago. It employs two main technologies, fiber optics using a physical wire and Free Space Optical (FSO) wireless transmission. Fiber optics has been well developed over the years in terms of distance, bandwidth, speed, reliability, and other enhancements that contribute to its use. Recent developments in FSO transmission has made it the mainstream and a better alternative compared to RF wireless transmission, concerning all parameters. In this chapter, we focus on advancements in OC that represent innovative ideas of how to enable new methods of secured optical data transmission in different ways and not simply as an extension to current methods and technologies.


Author(s):  
S. Basu ◽  
D. F. Parsons

We are approaching the invasiveness of cancer cells from the studies of their wet surface morphology which should distinguish them from their normal counterparts. In this report attempts have been made to provide physical basis and background work to a wet replication method with a differentially pumped hydration chamber (Fig. 1) (1,2), to apply this knowledge for obtaining replica of some specimens of known features (e.g. polystyrene latex) and finally to realize more specific problems and to improvize new methods and instrumentation for their rectification. In principle, the evaporant molecules penetrate through a pair of apertures (250, 350μ), through water vapors and is, then, deposited on the specimen. An intermediate chamber between the apertures is pumped independently of the high vacuum system. The size of the apertures is sufficiently small so that full saturated water vapor pressure is maintained near the specimen.


Author(s):  
Earl R. Walter ◽  
Glen H. Bryant

With the development of soft, film forming latexes for use in paints and other coatings applications, it became desirable to develop new methods of sample preparation for latex particle size distribution studies with the electron microscope. Conventional latex sample preparation techniques were inadequate due to the pronounced tendency of these new soft latex particles to distort, flatten and fuse on the substrate when they dried. In order to avoid these complications and obtain electron micrographs of undistorted latex particles of soft resins, a freeze-dry, cold shadowing technique was developed. The method has now been used in our laboratory on a routine basis for several years.The cold shadowing is done in a specially constructed vacuum system, having a conventional mechanical fore pump and oil diffusion pump supplying vacuum. The system incorporates bellows type high vacuum valves to permit a prepump cycle and opening of the shadowing chamber without shutting down the oil diffusion pump. A baffeled sorption trap isolates the shadowing chamber from the pumps.


Author(s):  
Mickey E. Gunter ◽  
F. Donald Bloss

A single, reasonably homogeneous, nonopaque 30-to-300 μm crystal, mounted on a spindle stage and studied by immersion methods under a polarizing microscope, yields optical data frequently sufficient to identify and characterize a substance unequivocally. The data obtainable include (1) the orientation of the crystal's principal vibration axes and (2) its principal refractive indices, to within 0.0002 if desired, for light vibrating along these principal vibration axes. Spindle stages tend to be simple and relatively inexpensive, some costing less than $50. They permit rotation of the crystal about a single axis which is parallel to the microscope stage. This spindle or S-axis is thus perpendicular to the M-axis, namely the microscope stage's axis of rotation.A spindle stage excels when studying anisotropic crystals. It orients uniaxial crystals within minutes and biaxial crystals almost as quickly so that their principal refractive indices - ɛ and ω (uniaxial); α, β and γ (biaxial) - can be determined without significant error from crystal misorientation.


Author(s):  
Dai Dalin ◽  
Guo Jianmin

Lipid cytochemistry has not yet advanced far at the EM level. A major problem has been the loss of lipid during dehydration and embedding. Although the adoption of glutaraldehyde and osmium tetroxide accelerate the chemical reaction of lipid and osmium tetroxide can react on the double bouds of unsaturated lipid to from the osmium black, osmium tetroxide can be reduced in saturated lipid and subsequently some of unsaturated lipid are lost during dehydration. In order to reduce the loss of lipid by traditional method, some researchers adopted a few new methods, such as the change of embedding procedure and the adoption of new embedding media, to solve the problem. In a sense, these new methods are effective. They, however, usually require a long period of preparation. In this paper, we do research on the fiora nectary strucure of lauraceae by the rapid-embedding method wwith PEG under electron microscope and attempt to find a better method to solve the problem mentioned above.


2019 ◽  
Vol 3 (6) ◽  
pp. 707-711 ◽  
Author(s):  
Andrew Peterson ◽  
Adrian M. Owen

In recent years, rapid technological developments in the field of neuroimaging have provided several new methods for revealing thoughts, actions and intentions based solely on the pattern of activity that is observed in the brain. In specialized centres, these methods are now being employed routinely to assess residual cognition, detect consciousness and even communicate with some behaviorally non-responsive patients who clinically appear to be comatose or in a vegetative state. In this article, we consider some of the ethical issues raised by these developments and the profound implications they have for clinical care, diagnosis, prognosis and medical-legal decision-making after severe brain injury.


2000 ◽  
Vol 12 (4) ◽  
pp. 380-380
Author(s):  
Kazuei Ogoshi ◽  
Taiji Akamatsu ◽  
Hiroyasu Iishi ◽  
Daizo Saito ◽  
Nobuhiro Sakaki ◽  
...  
Keyword(s):  

2011 ◽  
Vol 44 (8) ◽  
pp. 14-15
Author(s):  
MARY ANN MOON
Keyword(s):  

Crisis ◽  
2013 ◽  
Vol 34 (4) ◽  
pp. 289-292 ◽  
Author(s):  
Laurent Auzoult ◽  
Sid Abdellaoui

Background: Suicide prevention is a major challenge for penal institutions in many countries. The traditional approach relies on the expertise of health professionals and is supplemented by the intervention of other professionals and the inmates themselves. New methods of suicide prevention based on peer support have been developed in recent years. Peer prevention programs rely on the ability of inmates to identify suicide risk. Aims: This study examines perceived suicide risk among inmates and explores possible explanations. Method: 54 inmates and 17 professionals working in prisons responded to a questionnaire. Results: The peer prevention program was found to change inmates’ expectations of support in the event of a suicide crisis. The study also found that the inmates involved in the program tended to underestimate the risk of suicide. The perception of the prevention program and the level of self-consciousness were found to account for the underestimation of suicide risk. Conclusions: Support for inmates involved in suicide prevention programs must take into account their isolation in prison. The training provided to inmates must also consider the biases affecting the assessment of risk.


PsycCRITIQUES ◽  
2006 ◽  
Vol 51 (7) ◽  
Author(s):  
Peter Merenda

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