The Deployment of Curved Closed Tubes

1996 ◽  
Vol 118 (3) ◽  
pp. 337-339 ◽  
Author(s):  
G. Greschik ◽  
K. C. Park
Keyword(s):  
Cross Section ◽  
Critical Review ◽  
The Other ◽  
Collapsible Tube ◽  
The Cross

A critical review of previous work on the unfurling of helically curved tubes (Greschik et al, 1994, 1996) is conducted, which leads to the proposition of a continuous and smooth deployment concept akin to the Collapsible Tube Mast (Aguirre, 1985) for curved tubes. This involves the collapse of the cross section and the subsequent roll-up of its halves one upon the other onto a storage drum. The concept’s applicability to closed tubes is investigated and a method for the alleviation of the deleterious membrane strains in the stowed state is proposed.

A New Approach to the Demonstration of Oxidase-Localization Using Tannic Acid Or Catechin

1973 ◽  
Vol 31 ◽  
pp. 698-699
Author(s):  
V. Mizuhira ◽  
Y. Futaesaku
Keyword(s):  
Cross Section ◽  
Tannic Acid ◽  
Elastic Fiber ◽  
The Other ◽  
New Approach ◽  
Tissue Block ◽  
Active Reaction ◽  
The Cross

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.

Diversity and evolution of stem structure in Eleocharis (Cyperaceae)

Rodriguésia ◽  
2021 ◽  
Vol 72 ◽  
Author(s):  
Jaqueline Priscila Bispo de Almeida Cardoso Marcondes ◽  
Rafael Trevisan ◽  
Maria Cecilia de Chiara Moço ◽  
Cleusa Bona
Keyword(s):  
Cross Section ◽  
Morphological Analysis ◽  
Plant Size ◽  
Molecular Data ◽  
The Other ◽  
Air Gaps ◽  
Ecological Aspects ◽  
The Cross ◽  
Poorly Drained Soils ◽  
Stem Structure

Abstract Eleocharis (Cyperaceae) includes more than 300 species of perennial or annual herbs, frequently found on poorly drained soils. The species are morphologicaly similar, and the taxonomy is difficult because their vegetative and reproductive structures are very reduced. Previous study on the stem architecture in the subgenus Limnochloa showed that anatomical features help in the interpretation of the evolution, taxonomy and ecological aspects of the group. Our objectives were to add new characters from the stem (= culm) structure, to explore the characters in a greater number of Eleocharis species, representatives of the other subgenera, and add these data in a new phylogenetic analysis with molecular data. The study covered 68 species obtained from herbaria and fixed material. In addition to the stem architecture, the internal organization of the tissues, the cross-section format, the presence or absence of stretched cells in aerenchyma air gaps and the plant size were included in the morphological analysis. Our data confirm that spongy aerenchyma pattern is the ancestral condition while the mixed and septate patterns occurred independent and punctually. Only the cross-section format was variable among specimens while the other characters were uniform and relevant for taxonomic use.

The Bakerian lecture.— On the forms of equipotential curves and surfaces and on lines of flow

1876 ◽  
Vol 24 (164-170) ◽  
pp. 1-32
Keyword(s):  
Cross Section ◽  
Outer Boundary ◽  
The Other ◽  
Curves And Surfaces ◽  
Conducting Wire ◽  
The Wire ◽  
The Cross ◽  
Current Flows ◽  
The One

When any portion of a conducting-wire which joins the two poles of a voltaic battei'y is increased in size, the resistance of the circuit is diminished and a greater current flows through the wire ; and as any increase in the cross section of any portion of the wire causes a corre­sponding increase in the current, it is clear that there is no part of the conducting-wire through which some portion of the current does not flow from the one pole to the other; and the outer boundary of such a wire will be a line of flow. A line of flow is a line drawn in a conductor which indicates at every point of it the direction of the current at that point. A portion of the conductor completely enclosed by lines of flow may be termed a tube of flow.

DISTRIBUTION OF ELEMENTS IN HUMAN SPINAL CORD

1992 ◽  
Vol 02 (04) ◽  
pp. 433-440 ◽  
Author(s):  
MASAE YUKAWA ◽  
T. KOBAYASHI ◽  
Y. QIU ◽  
N. KAMEDA ◽  
Y. ITO ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Cross Section ◽  
The Other ◽  
Current Understanding ◽  
Human Spinal Cord ◽  
Lumbar Level ◽  
Distribution Of Elements ◽  
The Cross

The distribution of elements in human spinal cord was investigated on unfixed frozen cord material using PIXE technique. Distribution of Cu, Zn and Fe were not uniform in the cross section of the spinal cord and concentrations of these elements were higher in the anterior gray horn than in the other areas, while K and Cl distributed uniformly. The content of K changed along the spinsl cord from the cervical to the lumbar level. These findings are discussed in relation to current understanding of the physiology of the spinal cord.

scholarly journals GENERAL CASE OF REINFORCED CONCRETE ROD ELEMENTS CALCULATION USING THE DIAGRAM METHOD

2021 ◽  
Vol 93 (1) ◽  
pp. 26-37
Author(s):  
O.V. RADAYKIN ◽  
◽  
L.S. SABITOV ◽  
L.SH. AKHTYAMOVA ◽  
T.P. ARAKCHEEV ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Longitudinal Force ◽  
Internal Force ◽  
The Other ◽  
Bending Moments ◽  
Diagram Method ◽  
The Cross ◽  
Three Components

In SP 63.13330 the general calculation case for the diagram method is oblique off-center compression, which takes into account only three components of internal force factors in the cross section: the longitudinal force-Nz – and two bending moments relative to the corresponding axes – Mx and My. The other three components-the QX and Qy transfer forces and the MZ torque – are left out of consideration. In addition, for this case, the search in the available literature, including the founders of the diagram method, for the output of calculation formulas was not successful – in all sources they are given in ready-made form without evidence. This article is intended to try to fill in these gaps. For this purpose, based on the expressions for rod displacements that are generally accepted in mechanics, in particular on the Mora integral of displacements, the resolving expressions of the diagram method are obtained in the most general form.

The Shock Tube

1954 ◽  
Vol 58 (524) ◽  
pp. 541-546 ◽  
Author(s):  
B. D. Henshall
Keyword(s):  
Shock Tube ◽  
Cross Section ◽  
Research Tool ◽  
The Other ◽  
Physical Description ◽  
The Cross

In recent years interest has been revived in an apparatus which was first developed more than fifty years ago. This apparatus, which is known today as a shock tube, is a very useful research tool, the versatility of which is not generally appreciated in this country. In this paper the author attempts to give a clear physical description of the flow in a shock tube and a review of the problems which may be investigated by means of this apparatus.Basically, a shock tube consists of a simple fabricated duct which may be closed or open at one end, and closed at the other end. A diaphragm divides this duct into two compartments which initially contain gases at different pressures. In a conventional shock tube the cross-section is constant, the ends are closed, and air is used on both sides of the diaphragm (Fig. 1).

scholarly journals ASYMPTOTIC BEHAVIOR OF STRUCTURES MADE OF CURVED RODS

2008 ◽  
Vol 06 (01) ◽  
pp. 11-22 ◽  
Author(s):  
GEORGES GRISO
Keyword(s):  
Asymptotic Behavior ◽  
Variational Problem ◽  
Cross Section ◽  
A Priori Estimates ◽  
A Priori ◽  
The Other ◽  
Linearized Elasticity ◽  
Curved Rods ◽  
The Cross ◽  
Linearized Elasticity System

In this paper, we study the asymptotic behavior of a structure made of curved rods of thickness 2δ when δ tends to 0. This study is carried on within the frame of linear elasticity by using the unfolding method. It is based on several decompositions of the structure displacements and on the passing to the limit in fixed domains. We show that any displacement of a structure is the sum of an elementary rods-structure displacement (e.r.s.d.) concerning the rods' cross sections and a residual one related to the deformation of the cross section. The e.r.s.d. coincides with rigid body displacements in the junctions. Any e.r.s.d. is given by two functions belonging to [Formula: see text] where [Formula: see text] is the skeleton structure (i.e. the set of rods with middle lines). One of this function [Formula: see text] is the skeleton displacement, the other [Formula: see text] gives the cross section rotation. We show that [Formula: see text] is the sum of an extensional displacement and an inextensional one. We establish a priori estimates and then, we characterize the unfolded limits of the rods-structure displacements. Eventually, we pass to the limit in the linearized elasticity system and using all results in [6], where on one hand, we obtain a variational problem that is satisfied by the limit extensional displacement, and on the other hand, a variational problem coupling the limit of inextensional displacement and the limit of the rod torsion angles.

Elastic Scattering of Electrons and Positrons by Screened Nuclei

1966 ◽  
Vol 21 (9) ◽  
pp. 1321-1327 ◽  
Author(s):  
Elmar Zeitler ◽  
Haakon Olsen
Keyword(s):  
Elastic Scattering ◽  
Cross Section ◽  
Cross Sections ◽  
Relativistic Effects ◽  
The Other ◽  
Elastic Electron ◽  
Positron Scattering ◽  
Electrons And Positrons ◽  
Two Factors ◽  
The Cross

Results of calculations of cross sections for elastic electron and positron scattering are given in angular steps of 15 degrees for elements Z=6, 13, 29, 50, 82, and 92 and energies T=0.2, 0.4, 0.7, 1, 2, 4, and 10 MeV. The calculation is based on the separability of the cross section into two factors, one describing screening and the other, spin and relativistic effects. The first factor is obtained by the MOLIÈRE approximation 8. The second factor is taken from a paper by DOGGETT and SPENCER 5. Different screening potentials for Z=29 were applied.

scholarly journals Design and Manufacturing of Fixture for Edge Prepration of Elbows

2018 ◽  
Vol 7 (3.34) ◽  
pp. 339
Author(s):  
Nagasankar P ◽  
Tamilselvi P ◽  
Babu T V B ◽  
Jasim Salahudin S ◽  
Aravindhan S ◽  
...  
Keyword(s):  
Cross Section ◽  
The Other ◽  
Design And Manufacturing ◽  
Manual Handling ◽  
The Cross ◽  
Edge Preparation

This paper is a description of an alternative fixture for the edge preparation of elbows and pipes before welding. The welding will not penetrate the cross section of the pipe if the thickness of the pipes is more than eight millimeter, so edge preparation is done before welding. Fixtures are used to hold the pipes during the process of edge preparation. This paper deals with two major issues from the design of previous fixtures.Requirement of manual handling of the part.Precise rotations are not possible. The fixtures being used currently require more setting up time and they require manual handling to machine the other side. This paper describes a fixture which can reduce manual handling and be able to rotate the elbow either manually or using a motor.  

scholarly journals Amplified cross-linking efficiency of self-assembled monolayers through targeted dissociative electron attachment for the production of carbon nanomembranes

2017 ◽  
Vol 8 ◽  
pp. 2562-2571 ◽  
Author(s):  
Sascha Koch ◽  
Christopher D Kaiser ◽  
Paul Penner ◽  
Michael Barclay ◽  
Lena Frommeyer ◽  
...  
Keyword(s):  
Cross Section ◽  
Current Density ◽  
Electron Attachment ◽  
The Other ◽  
Self Assembled Monolayers ◽  
Cross Linking ◽  
Dissociative Electron Attachment ◽  
Electron Dose ◽  
Assembled Monolayers ◽  
The Cross

The determination of the negative ion yield of 2′-chloro-1,1′-biphenyl (2-Cl-BP), 2′-bromo-1,1′-biphenyl (2-Br-BP) and 2′-iodo-1,1′-biphenyl (2-I-BP) upon dissociative electron attachment (DEA) at an electron energy of 0 eV revealed cross section values that were more than ten times higher for iodide loss from 2-I-BP than for the other halogenides from the respective biphenyls (BPs). Comparison with dissociative ionization mass spectra shows that the ratio of the efficiency of electron impact ionization induced fragmentation of 2-I-BP, 2-Br-BP, and 2-Cl-BP amounts to approximately 1:0.7:0.6. Inspired by these results, self-assembled monolayers (SAMs) of the respective biphenyl-4-thiols, 2-Cl-BPT, 2-Br-BPT, 2-I-BPT as well as BPT, were grown on a Au(111) substrate and exposed to 50 eV electrons. The effect of electron irradiation was investigated by X-ray photoelectron spectroscopy (XPS), to determine whether the high relative DEA cross section for iodide loss from 2-I-BPT as compared to 2-Br-BP and 2-Cl-BP is reflected in the cross-linking efficiency of SAMs made from these materials. Such sensitization could reduce the electron dose needed for the cross-linking process and may thus lead to a significantly faster conversion of the respective SAMs into carbon nanomembranes (CNMs) without the need for an increased current density. XPS data support the notation that DEA sensitization may be used to achieve more efficient electron-induced cross-linking of SAMs, revealing more than ten times faster cross-linking of 2-I-BPT SAMs compared to those made from the other halogenated biphenyls or from native BPT at the same current density. Furthermore, the transfer of a freestanding membrane onto a TEM grid and the subsequent investigation by helium ion microscopy (HIM) verified the existence of a mechanically stable CNM created from 2-I-BPT after exposure to an electron dose as low as 1.8 mC/cm2. In contrast, SAMs made from BPT, 2-Cl-BPT and 2-Br-BPT did not form stable CNMs after a significantly higher electron dose of 9 mC/cm2.

Sign in / Sign up

Export Citation Format

Share Document